Industrial & Specialty Printing - January / February 2011

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• Automating Your Pad-Printing Operation Automation is an important part of efficient, consistent pad printing.

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• Membrane Switch: Screen Printing 101 The membrane-switch market has experienced dramatic growth and soared to an unprecedented level.

• Industry Insider The Importance of Printed Electronics to P&G

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CONTENTS

INDUSTRIAL + SPECIALTY PRINTING January/February 2011 • Volume 02/Issue 01

23

FEATURES

12 Advanced RFID Tagging Applications Create New Opportunities for Specialized Printing Bob Hamlin, Tego, Inc.

New tag types and packaging technologies are getting a start in aviation and expanding into new areas.

16 Focusing on Film-Insert Molding, Part 2 Neil Bolding, Jim Plamann, and Peter Warwick, MacDermid Autotype

This wraps up the two-art article on film-insert molding with a discussion on films, processing, and finishing.

20 A Look at Large-Format Pad Printing Julian Joffe, Pad Print Machinery of Vermont

When substrates are rough or undulating, or three-dimensional in nature, pad printing can make easy work of large-format applications.

23 OLEDs Shine a Whole New Light on Displays Joseph Fjelstad, Verdant Electronics

Read this article to learn how OLEDs work, who is making what, and which opportunities can make a difference to printers of high-definition displays.

26 Sticking with Printable Adhesives Lisa Krueger Castillo, KIWO, Inc.

This article describes the characteristics of print-applied adhesives and their use in industrial applications.

30 SGIA Review

Ben P. Rosenfield and Gail Flower

Take a look at the latest predictions and products for industrial printing from SGIA 2010. www.linkedin.com/ groups?gid=2658424

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INDUSTRIAL + SPECIALTY PRINTING, (ISSN 2125-9469) is published bi-monthly by ST Media Group International Inc., 11262 Cornell Park Dr., Cincinnati, OH 45242-1812. Telephone: (513) 421-2050, Fax: (513) 362-0317. No charge for subscriptions to qualified individuals. Annual rate for subscriptions to non-qualified individuals in the U.S.A.: $42 USD. Annual rate for subscriptions in Canada: $70 USD (includes GST & postage); all other countries: $92 (Int’l mail) payable in U.S. funds. Printed in the U.S.A. Copyright 2011, by ST Media Group International Inc. All rights reserved. The contents of this publication may not be reproduced in whole or in part without the consent of the publisher. The publisher is not responsible for product claims and representations. POSTMASTER: Send address changes to: Industrial + Specialty Printing, P.O. Box 1060, Skokie, IL 60076. Change of address: Send old address label along with new address to Industrial + Specialty Printing, P.O. Box 1060, Skokie, IL 60076. For single copies or back issues: contact Debbie Reed at (513) 421-9356 or Debbie.Reed@STMediaGroup.com. Subscription Services: ISP@halldata.com, Fax: (847) 763-9030, Phone: (847) 763-4938, New Subscriptions: www.industrial-printing.net/subscribe.

COLUMNS 8 Business Management

Steve Gilbertson, Kammann USA The author talks about direct printing on bottles as a means of eliminating some waste while creating recyclable products.

10 Safety Management

Gregory A. Burr, CIH; Elena H. Page, M.D., M.P.H. ; Maureen T. Neimeier, B.B.A., NIOSH Learn how one printer reported eye symptoms among employees to NIOSH and what NIOSH suggested to prevent the adverse reactions.

37 Industry Insider

Ray Greenwood, SGIA As a leader of the membraneswitch and printed-electronics activities in the SGIA, Greenwood looks at the near-future of industrial printing from a practical viewpoint.

DEPARTMENTS 4 Editorial Response 5 Product Focus 34 Industry News 34 Upcoming Events 39 Advertising Index 40 Shop Tour ON THE COVER

Wafers hold thousands of ASIC chips.

The heart of an RFID tag is the electronic ASIC chip that stores the ID number and handles communications with the reader. Find out more about new RFID technologies on page 12. Cover concept courtesy of Tego, Inc. Cover design by Keri Harper.

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EDITORIAL RESPONSE

Printed-Electronics Market Shows Growth GAIL FLOWER Editor

The printed-electronics market has bumped along for quite a few years. Now, as the recession winds down, the industry has begun to show signs of steady growth. For instance, forecaster iSuppli declared that global revenue from consumer-electronics manufacturing in 2010 is rebounding from the downturn of 2009, setting stage for a sustained rise during the next four years. That’s reassuring as more consumer-electronics manufacturers turn to printing and other low-cost production methods. iSuppli says that OEM revenue for consumer electronics in 2010 is projected to reach $304.4 billion, up 6.2% from $320.7 billion last year.

IDTechEx predicts that the printed-electronics market will grow to more than $50 billion over the next ten years, including display technologies, photovoltaics, and logic representing the largest segments. Lots of positive news broke at their Printed Electronics USA conference in Santa Clara, CA, November 30 to December 3.

Heraeus announced that they are furthering growth in their product range for the electronics industry by the sale of the Clevios conductivepolymers business unit of H.C. Starck GmbH to Heraeus, Germany effective December 1, 2010. Clevios shared the conference stand with Heraeus at Printed Electronics USA. Heraeus Precious Metals Business Group has long been known for supplying metallic materials such as pastes and inks to the electronics industry, and now it can add the Clevios conductive polymers to its offerings, including a range of PEDOT: PSS polymers and related chemicals. From paste to flexible substrates, more materials that fit the printed-electronics marketplace are now coming from the company.

PARC (Palo Alto Research Center), a center for commercial innovation, and Soligie Inc., a provider of design and manufacturing services for flexible and printed electronics, also announced an agreement aimed at advancing the

commercialization of printed-electronics technologies and capabilities. By working together, both companies plan to help their customers bring a range of novel and custom electronic solutions to the market. One of the disconnects in printed technologies has been a noted gap in the concept-to-market pathways for printed electronics. This sounds like a bit of Americanized IMEC, though without the government support.

The conference’s display floor abounded with new machinery, materials, and services.

For example, the Korea Institute of Machinery & Materials displayed a printed electromechanical system, a lab-scale press printing roll-to-roll for manufacturing electronics with micrometer precision using a variety of techniques (inkjet, gravure, offset, flexo, and pad printing). It filled the entire booth. Aixtron AG won the Technical Development Manufacturing Award for its organic thin-film vaporphase-deposition equipment, a truly disruptive technology that could affect the speed of OLED production.

If you wanted to see some current and future devices at the conference, a stroll down Demonstration Street at Printed Electronics USA provided some real-life examples. Mannequins wore electroluminescent T-shirts. Solar lamps manufactured at Riso National Labs in Denmark lighted the area. Neuber’s solar bag, incorporating a flexible, organic, photovoltaic solar cell by Konarka, was displayed so that a visitor could see the battery charger unit for notebooks and cell phones on the inside of the shoulder bag. Many international travelers would have bought one had the solution been available for purchase on site. The Morphpad, Mflex’s flexible-circuit-technology offering, was integrated into the Toshiba Biblio e-book reader/mobile phone on display. Many signs and posters using electroluminescent ink hung on the walls of the darkened display area. OLEDs made several new products glow with light.

When printed electronics really becomes a mainstream manufacturing process, it could create jobs worldwide, giving employment to many and a changed lifestyle to all.

4 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net

Industrial + Specialty Printing www.industrial-printing.net

STEVE DUCCILLI Group Publisher steve.duccilli@stmediagroup.com GREGORY SHARPLESS Associate Publisher gregory.sharpless@stmediagroup.com GAIL FLOWER Editor gail.flower@stmediagroup.com BEN P. ROSENFIELD Managing Editor ben.rosenfield@stmediagroup.com KERI HARPER Art Director keri.harper@stmediagroup.com LINDA VOLZ Production Coordinator linda.volz@stmediagroup.com BUSINESS DEVELOPMENT MANAGERS Lou Arneberg – Midwest Lisa Zurick – East US, East Canada, Europe Ben Stauss – West US, West Canada, Asia EDITORIAL ADVISORY BOARD Joe Fjelstad, Dolf Kahle, Bruce Kahn, Ph.D., Rita Mohanty, Ph.D., Mike Young, Wim Zoomer

JERRY SWORMSTEDT Chairman of the Board TEDD SWORMSTEDT President JOHN TYMOSKI Associate Director/Online

CUSTOMER SERVICE Industral + Specialty Printing Magazine Customer Service P.O. Box 1060 Skokie, IL 60076 ISP@halldata.com F: 847-763-9040

The latest equipment and materials for industrial printing

FUJIFILM Dimatix (www. dimatix.com) recently introduced its DMP-5000 Series Materials Printer.

The company says the news system features a (500 x 500-mm) printable area with positional accuracy and repeatability of ±5 and ±1 µm and accommodates multiple interchangeable printheads with drop volumes from 1-35 pl with both individually calibrated and tunable jets supported. The large-format, non-contact, fluid-deposition system is capable of jetting functional fluids and uses a temperature-controlled vacuum platen to register, maintain, and thermally manage substrates during printing. Examples include plastic, glass, ceramics, and silicon, as well as flexible substrates such as membranes, gels, thin films, and paper products. The DMP-5000 includes an integrated drop-visualization system that captures droplet formation images dynamically as dropletejection parameters are adjusted to produce a tuned printhead and fluid combination. The printhead can be calibrated on a per-nozzle basis to compensate for channel-to-channel variability. A second camera system allows substrate measurements and alignment, observations of fluiddrying behavior, with droplet measurement and placement calculations.

product focus

Materials-Deposition System

Label Media for Roland Inkjet Printers Roland DGA Corp. (www.rolanddga.com) and FLEXcon (www. flexcon.com) recently teamed up to bring users of Roland’s VersaUV LEC series of UV-LED wide-format inkjet printer/cutters a specialized pressure-sensitive polypropylene media for labeling applications. The companies say Roland’s VersaUV LEC Series inkjet printer in combination with FLEXcon’s FLEXmark polypropylene produce durable, high-quality labels for product identification and product-promotion applications. FLEXmark polypropylene label media is available in 30-in. x 150-ft (762mm x 45.7-m) rolls and in 2.0-mil clear, 2.3-mil white, and 2.0-mil metalized-silver formats. january/february 2011 |

Redesigned Pad Printers

Pad Print Machinery of Vermont (www.padprintmachinery.com) says it has redesigned KP Series pad-printing presses with an emphasis on operator accessibility, safety, and ability to view the support table. With the new design, the sealed cup remains stationary while the cliche, mounted to the support, moves forward and back. The pad is in the back position as the cycle starts, and Pad Print Machinery says the operator can work unobstructed while loading and unloading parts, thereby increasing productivity and simplifying tooling design.

Screen Wash

Hot-Stamping System Spartanics (www. spartanics.com) says it designed the new M590 hot-stamping machine for optimum efficiency for finishing secure and non-secure foil feature cards and similar printed products. The system can be used inline with other finishing solutions from Spartanics or as a standalone unit. Applications include cards, metal and plastic nameplates, packaging, branding, and security. M590 supports output of up to 540 hot stamps/min and can accommodate multiple stamps simultaneously (six-up and more). It registers sheet or web materials in X, Y, and/or Theta (rotation) and can be customized to specific application requirements. Each foil stamp is adjusted individually and automatically for pressure, flatness, temperature, and dwell time.

Inkjet System for Packaging Applications

Easiway Systems, Inc. (www.easiway.com) added VersaSolv Concentrated Screen Wash to its line of screen-cleaning products.

The company describes it as an environmentally approved, highly concentrated screen wash that mixes with water, has low VOCs, is extremely quick penetrating and fast acting, and is designed to dissolve and clean a variety of screen inks from mesh without the hazards and odors usually associated with aggressive solvents. According to Easiway, VersaSolv, when mixed with water, conforms to the restrictions on solvent-based screen-cleaning products in California. VersaSolv is packaged in quarts, gallons, 5-gal pails, and 55-gal drums.

Print-Applied Adhesive KIWO (www.kiwo.com), recently introduced Kiwoprint D 159 AF, a print-applied adhesive formulated for automotive and electronics applications. KIWO says the adhesive provides very aggressive tack and high bond strength to most metals and plastics and that high viscosity allows printing onto absorbent surfaces, such as felt and PE foam. According to KIWO shear-adhesion-failure temperature of more than 203°F (95°C) enhances the printability of the waterbased acrylic formula through coarse mesh. Kiwoprint D 159 AF is an APEO-free adhesive. | Industrial + Specialty Printing www.industrial-printing.net

Xennia’s (www.xennia.com) new Aquamarine is an inkjet printer designed to print full-color graphics, logos, barcodes, and other data onto the sides of rigid boxes, cartons, and other types of packaging. The system uses UV or solvent inks and prints onto two opposing vertical sides of rigid EPS boxes, chill boxes, bottle crates, transit packs, plastic trays, and other secondary packaging. Aquamarine supports a maximum print height of 4.7 in. (120 mm) and speeds up to 131.2 ft/min (40 m/min), which Xennia says is the equivalent to more than 1800 boxes/hr using 31.5-in.

(800-mm) boxes. Automated maintenance and variable-data printing are also available. The system includes a substrate-transport conveyor, and it can be used as a standalone printing system or integrated into a production line.

Stencil-Printing Solution

Pad-Press-Setup System

ITW Trans Tech (www.itwtranstech.com) says its new ExpressPad is designed to allow users to replace pads with absolutely no tools, cut replacement time, and improve the precision and repeatability of pad placement. It can be used for short and long runs and is available in 2.4-, 3.5-, and 5.1-in. (60-, 90-, and 130-mm) configurations. ExpressPad is available on all ITW Trans Tech Aero and Syncro pad-printing presses, and retrofit systems are available for customers using other pieces of equipment.

Send us your product news!

Email ben.rosenfield@stmediagroup.com

DEK (www.dek.com) recently launched ProActiv, a process technology designed to enable electronics manufacturers to increase miniaturization. The company says its solution is ideal for manufacturers dealing with high-density heterogeneous boards and ultra-fine pitch assemblies. ProActiv is engineered to support consistent printing of small apertures for 0.01-in. (0.3-mm) CSPs and 01005 passives. It contains a control subsystem and a set of squeegees featuring embedded electronics. ProActiv energizes the paste that is in contact with, or in very close proximity to, the squeegee blade. DEK says the energizing action does not alter the paste, but causes it to be far more compliant, thereby improving the packing density of solder particles into apertures and enhancing the bond between those particles.

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business management

Building Profitability into Sustainable Packaging Steve Gilbertson Kammann USA

Sustainability is currently the front-running concern in the United States packaging industry. The trend has many packagers scrambling to find ways to respond to the need for eco-friendly packaging while minimizing disruption to their manufacturing infrastructure and production costs. Can a green package be an effective one that’s also efficient, high-quality, and profitable? Some European companies seem to have already discovered ways to achieve simultaneous quality, ecology, and cost-effective production.

There are a few decorating contractors in Europe and the U.S. who enjoy a solid reputation as innovative packagers, committed to leading the industry in effective packaging methods that produce high-quality results. These companies have always been direct-bottle branders who view labeled bottles as an inefficient and inferior quality product. With the burgeoning ecological trend overtaking the industry, this label-less production has put them at a great advantage.

Direct branding: ecological, economical, and aesthetic The direct-printing trend has been in full force since approximately mid 1980s due to the simplicity of the production process and the growing environmental concerns associated with the labeling process. Several companies have committed to direct bottle printing (Figure 1) since it entered the packaging market, in part due to the fact that the brands prefer direct bottle packaging to labels. The reasons are clear.

Ecology Label-less bottle equals clean scrap.

Glass is lauded as the one true cradle-to-

cradle, or endlessly recyclable product, as it is the most easily processed recycled container. Deterioration is rare, even when the glass is consistently recycled.

Adding a label, however, will render the glass un-recyclable if the label can’t be completely stripped, rendering it dirty scrap. Direct-to-glass printing solutions using eco-friendly lead-free inks ensure that the glass can be completely recycled indefinitely.

Direct printing also allows plastic molders to practice green manufacturing. The same recycling advantages of the direct-to-glass bottle-printing process can be applied to the market for plastic containers. Plastic molders practice green manufacturing by grinding rejected or scrap bottles in-house and then recycling the material. If the label can’t be stripped off the container, the dirty scrap is usually sold to an outside vendor instead of being recycled in the plant.

Direct printing reduces carbon footprints. Laminated labels contribute greatly to carbon footprints. Labels have many layers that need to decompose, including transparent plastic film and transparent pressure-sensitive-adhesive layers.

Direct printing is a viable alternative that reduces the materials and inventory requirements and greatly increases the recyclability of the container. Furthermore, a finished label is cookie-cut from a larger master version of the finished product. The finished label on a bottle is usually only 1/3 of the original, leaving 2/3 non-recyclable garbage. Direct printing eliminates this waste.

Economy Direct bottle printing can prove to be

| Industrial + Specialty Printing www.industrial-printing.net

the most efficient production method, assuming you use the right production equipment. Computerized screen-printing equipment (Figure 2) allows the decorator to make varied production runs on many different bottle sizes and shapes.

Many machines today are offered in a circular, rather than inline, design and allow the users to input computerized settings for different production runs versus the traditional mechanical method. This design gives them the ability to respond quickly to multiple changeovers and varied production runs. Computerized control reduces retooling times and productions costs.

Eliminating the pressure-sensitive label removes an entire process from the production workflow and the associated manpower, as well as the need to inventory label material. Direct printing facilitates a print-on-demand model without the need to store and potentially scrap millions of outdated, poorly designed/defective labels.

Aesthetics Direct screen printing provides users with the ability to deliver a variety of strong and opaque colors when their clients demand it. This feature gives decorators whose customers emphasize the quality image of their bottles the edge over other traditional bottle decorators. Screen printing has also provided decorators with the ability to offer a highly desirable tactile feel to the bottle.

Customer satisfaction Decorators attribute their many years of success to the ability to respond to customer needs. Many clients in the supply chain are filling companies that have

a strong preference for label-less bottles.

Filling material, be it food or cosmetics, can spill over onto the bottle, thereby affecting the label and rendering the bottle defective. Some containers are labeled by third parties in different facilities, sometimes in different countries, which make the process of reworking a spoiled container that much more costly.

Labels once enjoyed a surge in popularity due to the ability to customize a bottle using varying colors, sizes, and shapes. But now, with the computerized settings offered by computerized screenprinting equipment, these variations can be met with minimal retooling processes, while still enjoying the green effect and the superior look and feel that directbottle branding can offer.

Bottle packagers looking for ways to offer a green package in a competitive economy can take a huge leap forward by converting to direct-bottle branding, thereby eliminating the unattractive, unrecyclable, and inefficient processes associated with conventional labeling.

Today’s environment demands it; fortunately, today’s production solutions have evolved to rise to the occasion, providing quality and efficient branding methods that are also kind to the environment.

Why stay analog?

Manufacturers are now making innovative web-fed screen-printing and converting technologies available as individual plugand-play component modules (Figure 3).

In this highly adaptable format, you can incorporate one unit or several units of precision component technologies into your existing equipment—right where you need them most—and expand your capabilities instantly.

Options Decorators and convertors can customize their production configurations to meet specific in-house requirements and those of their customers. Options include flatbed and rotary screen printing, flexography, offset, hot and cold foil stamping, inkjet, hot air and UV/LED curing, a variety of computerized controls, and more.

Innovations have made these components more reliable, precise, efficient, and better overall in terms of quality.

More reliability Machine functions are operated with gearless drives for more control.

Figure 1 (top left) Direct glass printing streamlines the manufacturing workflow and reduces consumables use in the process.

Figure 2 (bottom) Enhanced precision afforded by computer numeric control (CNC) helps minimize waste by limiting rejects and maximizing the use of consumables.

Figure 3 (top right) Modular screen-printing stations allow container decorators to add colors inline as needed while maintaining the accuracy required for their work.

Better repeatability Operators can input job data directly at a main terminal, including image length, screen stroke, squeegee movement, kiss-cutting length, material tension, and material thickness.

Higher precision Cylinder print stations with flat screens enhance flexibility, precision, and quality.

Improved efficiency Reusable aluminum screen frames reduce costs, and quick-change printing plates reduce labor time.

More innovation Continuous-motion material transport through print stations is one example of the kind of developments that drive efficiency and accuracy.

Better quality Air-cooled UV-curingaggregates for efficient ink curing, chill rollers in UV-curing aggregate for heat reduction, and other technologies enhance output quality.

Now what?

The sustainability of decorating machines is as important as the packages they help create. Our world economy is demand-

ing change for the better. We have all experienced the impact of the economic downturns of the past few years. The ability to re-tool and utilize machines with maximum flexibility is available today.

Eco-friendly printing machines and decorating process, like hybrid automobiles are not an option for the future, they are a necessity.

Steve Gilbertson Kammann USA

Steve Gilbertson earned a bachelor’s degree in marketing from Winona State University in 1992. Prior to joining Kammann Machines, Inc., he was employed with Wallace, an RR Donnelley Company. Steve has held the positions of president and Midwest sales manager for Kammann. He is now the vice president of sales and marketing for the newly formed Kammann USA. Steve is a member of the Institute for Packaging Professionals, Society of Plastic Engineers, Organic Electronics Association, Society of Glass and Ceramic Decorators, and Specialty Graphic Imaging Association. january/february 2011 |

safety management

Visual Disturbances Related to Amine Exposure Gregory A. Burr, CIH; Elena H. Page, M.D., M.P.H.; Maureen T. Niemeier, B.B.A. NIOSH

Visual disturbances among employees at a flexo-printing company prompted its managers to request assistance from the National Institute for Occupational Safety and Health (NIOSH). The facility prints labels on paper or plastic using water-based, UV-cured, and fluorescent inks. The plant had approximately 100 employees working as press operators, rewinder operators, and press assistants. The facility was divided into two printing areas: the line division (approximately 15,000 sq ft) and the prime division (approximately 9,000 sq ft). Although adjacent to one another, the divisions were separated by a concrete wall and flexiblestrip doorway curtains.

Line-division employees were reporting eye problems. This division had eight highspeed (400-ft/min) printing presses and used primarily water-based inks for printing less detailed labels, such as those on milk and orange juice containers. Fluorescent inks were used occasionally; UV inks were not used.

Prime-division employees were not reporting vision problems. This division had seven lower-speed (150- to 175-ft/min) printing presses and primarily used waterbased inks to print detailed labels, such as those on cosmetics and automotive products. Fluorescent and UV inks were used in this division. Both divisions used 5-gal pails for holding inks before pumping the inks into troughs.

Managers reported to NIOSH that line-division employees were experiencing intermittent blurred vision at work. One employee was evaluated by an ophthalmologist who found a “film over his eyes.” Employees said their blurred vision was like looking through a fog or mist. The effect was most noticeable when looking at lights, causing a halo. Vision changes typically resolved within a couple of hours after leaving work.

However, it was difficult for employees to do their jobs and drive home safely. Symptoms were unpredictable, but they seemed to be increasing in frequency. Employees and managers were unable to associate these visual changes with use of a particular substance, but noticed that symptoms were only reported by line-division employees and only on Mondays through Thursdays, when production activity was highest.

After meeting with management and employee representatives, our team monitored the air for chemical exposures and assessed the exhaust ventilation system. We sampled in both divisions to identify air contaminants unique to these production areas.

We surveyed employees using a medical questionnaire and performed eye exams on line-division employees and any prime-division employees who had experienced visual disturbances in the past. Eye exams were conducted at the beginning and end of work shifts for one week.

We found an association between visual symptoms and exposure to two chemicals: dimethylaminoethanol (DMAE) in the water-based ink and clean print additive (used to lengthen drying time so the ink did not dry too quickly) and dimethylisopropanolamine (DMIPA) in the pH adjuster. DMAE and DMIPA belong to a class of chemicals called tertiary amines.

Amines, derived from ammonia, are classified as primary, secondary, or tertiary.

Tertiary amines irritate skin and mucous membranes and can cause headache, nausea, and faintness when inhaled. Published reports describe reversible effects, including blurred vision, halo vision, or blue-grey vision among people exposed to amines. At this facility, DMAE was found in the inks and in the clean print additive the prime division used to extend the drying time of the inks. No reports of visual disturbances

10 | Industrial + Specialty Printing www.industrial-printing.net

Figures 1 and 2 This employee’s cloudy cornea at the end of a work shift (top) was determined to be caused by exposure to dimethylisopropanolamine, a tertiary amine.

The same employee’s cornea (bottom) is clear the next day.

in humans exposed to DMAE were in the scientific literature at the time of our evaluation. Animal experiments have documented corneal clouding, swelling, and ulcer (infection) with exposures to DMAE. DMIPA, which was used in the pH adjuster at this facility, had not been reported to cause visual disturbances in humans. There are no occupational exposure limits (OELs) for DMAE or DMIPA. We found visual symptoms including blurry, halo, and blue-grey vision; corneal opacity (clouding); and decrements in visual acuity (ability to read the 20/20 vision line of an eye chart) and contrast sensitivity (ability to detect a pattern on a similar

background). Figure 1 shows an employee’s cloudy cornea at the end of a work shift, while Figure 2 shows clearing of the same cornea the next day. We found that air exhausted from the facility was getting back inside and concluded that ventilation in the line division was inadequate. We recommended covering ink containers and the use of butyl rubber gloves (not latex rubber).

Butyl rubber is impermeable to amines, isopropyl alcohol, ammonia, and 2-butoxyethanol (the chemicals in use). We also recommended air monitoring after process changes, or when new chemical products are introduced.

The company immediately reduced the amount of DMIPA used in both divisions by diluting the pH adjuster that contained DMIPA with water and improved ventilation. We, and the company, suspected DMIPA to be the primary cause of the employees’ vision problems because we measured higher DMIPA concentrations in the line division (the complaint area). The company eventually replaced the DMIPAcontaining product.

Fifteen months after our first evaluation, we returned to the facility to determine whether process changes, such as eliminating DMIPA, had reduced amine exposures.

We sampled the air for DMAE and DMIPA and asked employees if they were currently experiencing blurry vision at work.

No visual problems were reported. There was little to no DMIPA in the air in either division. DMAE was in the air, but in lower concentrations than we first measured. We concluded that ventilation improvements stopped the re-entry of exhausted air and that the health hazard related to DMIPA and DMAE was gone.

Health effects and occupational exposure limits Occupational exposure limits (OELs) suggest levels of exposure to which most employees may be exposed up to 10 hours per day, 40 hours per week for a working lifetime without experiencing adverse health effects. However, a small percentage of employees may experience adverse health effects even if they are not exposed to substances at levels higher than the OELs because of individual factors such as their personal susceptibility, pre-existing medical conditions, or hypersensitivity (allergy).

Some hazardous substances may act in combination with other workplace

exposures, the general environment, or with medications or personal habits of the employee to produce health effects even if the occupational exposures are below the exposure limit. Some substances can be absorbed by direct contact with skin and mucous membranes in addition to being inhaled, which contributes to the person’s overall exposure.

The Occupational Safety and Health Administration (OSHA) mandates legally enforceable permissible exposure limits (PELs) for workplaces covered by the Occupational Safety and Health Act. However, not all hazardous chemicals have specific OSHA PELs, and the legally enforceable and recommended limits for some substances may not reflect current healthbased information.

To eliminate or minimize identified hazards, we encourage, in order of preference, the use of the traditional hierarchy of controls: substitution or elimination of the hazardous agent, engineering controls (local exhaust ventilation, process enclosure, dilution ventilation), administrative controls (limiting time of exposure, employee training, work practice changes, medical surveillance), and personal protective equipment (respiratory protection, gloves, eye protection). This approach groups actions by their likely effectiveness in reducing or removing hazards. In most cases, the preferred approach is to eliminate hazardous materials or processes and install engineering controls to reduce exposure or shield employees.

Until such controls are in place, or if they are not effective or feasible, administrative measures and/or personal protective equipment may be needed.

General recommendations Consider the following actions, listed in order of preference, for reducing anime hazards: Substitution/elimination Eliminate or substitute amine-containing products with different products. If not possible, dilute the amine-containing product with water as much as possible without reducing the product’s effectiveness.

Ventilation Assess the ventilation system to see, for example, whether exhausted air is re-entering the building. Consult an industrial hygienist or ventilation engineer if necessary. Consider ventilation at or near the printing presses (local exhaust ventilation) to capture any airborne contaminants

released quickly and efficiently. Cover ink and chemical containers when not in use to reduce the amount of chemicals evaporating into the work environment.

Assessment of personal protective equipment (PPE) use Complete a comprehensive assessment (required by OSHA for all employers) to determine whether hazards are present, or likely to be present, that would require the use of PPE—safety glasses, protective gloves, respirators, and others. Employees must be trained in the use and maintenance of the PPE. OSHA requires written documentation that PPE hazard assessment and employee training have been completed. Information about PPE can be found at www.osha.gov/SLTC/ personalprotectiveequipment/index.html.

Skin protection Latex rubber gloves can cause allergies in some people, and some chemicals can permeate them. Instead, wear gloves made of materials such as butyl rubber, if appropriate for your workplace.

Consult a reference guide such as “Quick Selection Guide to Chemical Protective Clothing,” 5th Ed. (Krister Forsberg, S. Z. Mansdorf) to select appropriate PPE for the chemicals at your facility.

Working with NIOSH NIOSH, in the Centers for Disease Control and Prevention (CDC), conducts research and makes recommendations for the prevention of work-related injury and illness. The NIOSH health hazard evaluation (HHE) program is available for employees, employers, or union representatives to ask NIOSH’s experts for an investigation of their health and safety concerns.

NIOSH contacts the requestor and discusses the problems and how to solve them.

This may result in sending the requestor information, referring them to a more appropriate agency, or making a site visit (which may include environmental sampling and medical testing). If NIOSH makes a site visit, a report is provided that includes specific recommendations and general guidance for following good occupational-health practices. HHE reports are available online at www.cdc.gov/niosh/hhe.

Gregory Burr and Elena Page are employees of the National Institute for Occupational Safety and Health (NIOSH). Maureen Niemeier is a contract employee of NIOSH working as a health communications manager for National Associates, Inc.

january/february 2011 | 11

COVER STORY

Advanced RFID Tagging Applications Create NEW OPPORTUNITIES for Specialized Printing Bob Hamlin Tego, Inc.

New tag types and packaging technologies are getting a start in aviation and expanding into new areas.

12 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net

Figure 1 (opposite page) This ASIC chip, shown in wafer form, holds several thousand die.

Figure 2 (top) This photomicrograph shows a TegoChip that can hold up to 32 KB of non-volatile writable/readable memory. Its actual size is 3 x 1.4 mm.

Figure 3 (bottom) Flexible inlays used in RFID tags include the electronic chip attached to a copper antenna on a flexible substrate.

R

adio Frequency Identification (RFID) tags have been a mainstay in supply-chain management for many years and are starting to show up in some unlikely places.

High-memory tags are now used in aircraft parts to store 20- to 30-year maintenance histories directly on the parts.

This aerospace application requires that the tag be inflammable and withstand wide temperature ranges, shock, and vibration. This is just one area where industrial printing could ultimately be applied in conjunction with RFID technology to improve costs and efficiencies.

Paper documents are another area ripe for RFID applications. Despite the move to a digital world, many areas still rely on the printed word. An opportunity is looming for industrial printers to combine document printing with RFID-tagging technologies to create new uses and benefits. These could range from storing entire document copies on a printed tag, including photographs and related work, to cryptography information for document authentication.

In January of 2010, Airbus announced it would begin requiring its suppliers to deliver aircraft parts with RFID tags already attached and encoded. This announcement was significant for two important reasons. The first is that this represents the first time an airframe manufacturer

plans to use tags on flying aircraft and, as such, those tags will have to meet stringent requirements for harsh environments and long life. The second is that Airbus is requiring the use of high-memory tags, starting with 4-KB tags and moving quickly to 8 KB. The demand for additional memory in RFID tags has grown for many years. The challenge for high-memory-tag designers is to create a passive UHF tag. A passive tag takes its power only from the RF energy supplied over-the-air by the tag interrogator (also known as a reader). This means that only ultra-low power levels are available to run the tag and its memory.

The additional data-storage requirements by aerospace for long life and high temperature resistance are impossible to meet using standard RFID tags that use chargebased flash-memory arrays. However, recent developments present the possibilty of supporting up to 32 KB of non-volatile memory on standard, passive tags, thereby

opening up many new applications and opportunities, including those where printing is the viable solution.

Tag construction The heart of any RFID tag is the electronic ASIC chip that stores the identification number and handles the communications with the reader. In the case of the passive RFID that holds up to 32 KB of non-volatile writable/readable memory, shown in wafer form in Figure 1, wafers hold thousands of individual die. Producing these wafers and sawing them into chips is the first step in the tag-production process. A close-up photograph of the chip is shown in Figure 2. All that is necessary for operation is to connect the chip to an antenna.

The standard method for creating the antenna is to etch copper onto a flexible substrate such as PET. Only two or four electrical connections to chip are necessary, and this is sometimes done using january/february 2011 | 13

Figure 4 (top) This example shows a rigid, ruggedized inlay along with its encapsulation shell. The finished tag shown in the upper right is attached with an adhesive backing and can withstand temperatures up to 150°C. Figure 5 (bottom) This finished package includes the high-memory chip on a substrate that presents two large copper pads for attachment. The 50-Ω impedance of the pads is suitable for connection through inductive coupling.

for further ruggedization and to provide mounting options. Such an inlay with its encapsulation shell is shown in Figure 4.

The shell can be molded to include an open cavity that accepts the inlay, or the inlay can be encapsulated using injectionmolding techniques.

Most inlays are manufactured by copper etch, but this is a carryover from the supply-chain RFID industry and is done for high-speed, high-volume production and to keep costs down. The aerospace application represents an opportunity for the industrial printer because the volumes are initially small and features like ruggedness and inflammability are critical. If printing methods could be applied to the aerospace-tagging market, supply could begin at modest levels while product speed and costs issues are worked out, eventually leading to opportunities for higher volumes and in additional markets.

wirebonding techniques that involve stitching 1-mil wire from bond pads on the chip to copper pads on the substrate. The much more common method, however—especially for high-volume production—is to attach metal bumps or balls to the bond pads on the chip, then use flip-chip attachment methods to attach to the substrate. No bonding wires are used in a flip-chip attachment. Instead, the die is inverted and the bumps that were previously attached to the die make direct contact with metal pads on the substrate and are held in place through soldering or conductive adhesive.

The result is what is known as an inlay.

Examples are shown in Figure 3.

The inlays shown in Figure 3 use a flexible PET substrate and are common in supply-chain applications where the lifetime of the tag is expected to be short.

In aerospace applications, and specifically for tags that will be used on aircraft, the requirements are much more severe.

Tags, as well as the data stored on them, are required to last for 20-30 years and be capable of withstanding large temperature ranges as well as shock and vibration. They must also be inflammable and must not emit smoke in the presence of flame or high temperatures. A rigid inlay built on a durable substrate is used for these applications. The inlay is often encapsulated

14 | Industrial + Specialty Printing www.industrial-printing.net

Formatting the data New tag-construction methods are critical technologies for these applications, but the real advances are created by the storage possibilities of high memory. RFID tags traditionally have the capacity to store 96 digital bits and are used to hold an identification number only. But new RFID technology supports data storage up to 256 Kb on a single chip. Airbus plans to store all significant manufacturing information related to a part, known as the birth record, directly on the tag attached to the item. Additionally, details about any maintenance performed on an item will be stored in a part-history record during all maintenance events over the lifetime of a part. The ability to write to this new chip in the field using standard RFID interrogators allows anyone to write history records

involved with the part. As a result, the large storage capacity of the tag, in addition to acting as a repository of information about the item, becomes a communications medium across the supply chain.

The Airbus example is the first largescale use of high-memory tags and, as a result, is being watched by many industries. Airbus, along with other key players in aviation, is taking a standards-based approach to high-memory RFID. Instead of simply writing data to raw memory locations, a container structure is in use that is similar to the file-structure format used by computers. The container structure is standardized in the Air Transport Authority’s SPEC2000, and work is underway to align the format with ISO standards.

The container format allows data written by one interrogator to be located, read, and understood by any other interrogator.

Because data are stored in a self-describing fashion and have provisions for file types such as XML, the approach has garnered the attention of other industries and is being looked at carefully by players in oil and gas, pharmaceuticals, automotive, and others.

Tagging paper Now that high-memory tags are available, along with the storage standards needed to organize the data stored in memory, one emerging application of particular interest to the printing community is that of tagging paper documents. In spite of the rapid migration to a digital world, there are many circumstances that still rely on printed documents. Among them are law enforcement, judicial systems, legal departments, and many medical organizations. Many of these groups have already started tagging paper documents and file folders with RFID tags.

In the existing use cases, tagging is done strictly for identification purposes in an effort to improve workflow. With the availability of high-memory tags, additional information can be stored on the tag, thereby creating new uses and benefits.

For example, a facsimile of the document or detailed scans of small portions of the document could be stored on the tag along with cryptography information, thus providing a strong indication of the document’s authenticity. Or the entire document could be stored on the tag, thus

providing the option for rapid electronic viewing or processing, in addition to the paper copy that might be required for statutory or workflow reasons. In perhaps the most common case, the paper document might provide a necessary certificate or cover sheet, while the electronic tag holds a more complete repository, including photographs and related works.

Paper documents are currently tagged with identification tags that are of the peeland-stick label variety. This time-consuming manual intervention could be short-circuited with a printing approach, although some new technology is in order. A much more efficient workflow is to allow the printer to create both tagged and untagged documents. To do so, when creating tagged documents, the printer would print the readable/viewable portion of the document and would also print an antenna using specialized conductive inks. The remaining job would be to attach the RFID chip.

The wirebonding and flip-chip attachment methods described earlier involve close alignment of small structures. Bond pads are typically 50-100 μm2, and bumps used for flip-chip attachment are of similar size. As such, die attachment using these methods requires careful and expensive machine setups for production volumes.

But a new technology has emerged that may make die attachment suitable for a printing process—possibly even in standard printers.

Figure 5 shows a high-memory RFID device in a package format that is roughly the same size as the chip die and about twice as tall. In the photograph, the backside of the die can be seen on one side. The die in the package has already been attached to the substrate in flip-chip fashion. The substrate brings out two large copper pads for easy attachment to antennas. The copper pads are readily seen in the photograph.

In addition to the attachment benefits brought by the large pads, the package also includes an impedance-matching network so that a constant 50-Ω load is presented at the antenna port. That this impedance matching can occur in a package barely larger than the die is surely part of the magic, but it also results in huge benefits to the antenna designer and creates many attachment options. In fact, good electrical connection is not even necessary as the

copper pads will inductively couple to an antenna in proximity.

For paper documents it should be possible to print an antenna on the document, then simply attach this type of package on top using nothing more than a drop of adhesive. Alignment of the die is not critical and can be off by as much as several millimeters in any direction, so it is quite feasible for the die placement and attachment to be done by a printer is a very inexpensive fashion. This process is possible for virtually any volume and represents a great advantage over standard RFID production setups that are only economical for very large volumes.

Summary The combination of high-memory electronics in passive UHF designs and rugged packaging technology makes RFID tags attractive for new applications, and the standardized data formats put in place for these applications are being watched carefully by many industries. High-memory tags will eventually be ubiquitous. These evolutions represent great opportunities in the printing industry as tags will start to show up in unexpected places. Tagged documents, for example, lend themselves naturally to printing, and the advent of miniature RFID packages means even the formerly expensive die-attachment process can be handled by printers. These markets will be large and lucrative for those willing to pursue the technology and overcome its challenges.

Bob Hamlin Tego, Inc.

Bob Hamlin is Chief Technology Officer at Tego, Inc. where he is responsible for product development and future technology directions.

He is the architect of the company’s flagship TegoChip, a 32-KB passive UHF tag. Bob has more than 20 years of experience in semiconductor development and systems architecture. He has held senior engineering and management positions TranSwitch Corp., General Datacomm Industries, and International Fiber Systems. He holds 10 U.S. and international patents, with several more pending, and has a Bachelor of Science degree in electrical engineering from Carnegie Mellon University. january/february 2011 | 15

FEATURE STORY

Focusing on Film-Insert Molding, Part 2

The conclusion of this two-part article about the film-insertmolding process focuses on films, processing, and finishing.

Neil Bolding, Jim Plamann, and Peter Warwick MacDermid Autotype

M

ost assume that the film used in a film-insert-molded part must be the same polymer as the molding resin. While this is a good rule of thumb, it is not an absolute rule. Considerations include melting points of the film and the resin, shrink rates of the film, and resin warping.

The most important issue is to ensure that there is at least a reasonably close match between the melting points of the film and resin. Film that melts at a temperature much lower than that of the molding resin is at risk for melting, especially in areas close to the injection gate. The cooling effect of the tool provides some protection, but serious damage quickly becomes obvious at the point of mismatch as distortion to the print in the gate area. This is easily confused with ink wash, but it will occur even with the best ink when the film itself is melting.

Most of the films used in film-insert molding (FIM) have relatively high melting points and do not cause issues even with high-process-temperature resins like PC. PMMA is a notable exception and must be used with great care with pure PC and even PC/ABS blends. To be safe, it is better to use PMMA films only with PMMA resins.

A mismatch in the other direction can also be a problem. Film that melts at a point that is much higher than the resin’s process temperature makes poor adhesion very likely. This is because adhesion relies on intermingling of the two polymers at the interface. The problem is not necessarily insurmountable, however, 16 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net

because the ink can provide a bridging layer. If the ink adheres well to the film, and the resin adheres well to the ink, then all is well. Remember that there may be part areas that are free of ink, such as lenses. Poor adhesion may be tolerated in these areas, provided the areas are not close to a part edge, but careful testing is required to preclude field failures.

Different polymers expand differently upon heating and, therefore, shrink differently upon cooling. Part warping may occur when two such polymers are molded together. If the film is thin compared to the wall thickness of the part, this may not be a problem; but even then, the stresses built up by the differential shrinkage can challenge resin-to-film adhesion and lead to delamination, especially on thermal or mechanical shock testing.

These issues can generally be resolved by good cooperative design with material suppliers and processors. The possible exception is with polyolefin materials, which have very high shrink rates compared to other materials. Great care must be taken in testing when the combination of olefins with other polymers is proposed.

MECHANICAL REQUIREMENTS OF THE DECORATIVE LAYER Second-surface FIM requires the decorative layer to fulfill a structural and decorative function. Ink adhesion to the film and to the molding resin is important, and the cohesive strength of the ink layer is critical. High pigment levels, especially metal-flake pigments, reduce the cohesive strength of the ink and should be

REGISTRATION IN PRINTING Registration, both to the sheet edge and from color to color, is easier to achieve on a small sheet than on a large one. The registration system used should ideally be common to both printing and forming operations, and it is necessary to design registration marks into the artwork outside the part area to allow for punchregistration holes to be added prior to forming. Many factors in screen printing affect registration, most notably mesh selection and mesh tension.

FORMING In many ways, forming is the economic heart of the FIM process.

It is where projects are made or broken. Unlike processes using only 2-D shapes, where patterning the parts onto a sheet or roll of film effectively is simple, the need to create complex, 3-D shapes makes the prediction of material use through forming processes very difficult.

FORMING PROCESSES Available pressure is the main parameter that characterizes the forming process. If available pressure is low, then it will be difficult to form the film unless it is heated to a relatively high temperature. At these high temperatures, the film tends to relax and may sag. Internal stresses are released and the shape of the film changes. If the film is carrying a graphic image that needs to be positioned precisely onto the form profile, then film movement caused by heating can lead to disastrous loss of registration between print and form.

As forming pressure increases, the temperature required for the film to form decreases and print-to-form registration improves.

Unfortunately, there is always a trade-off. The film becomes more elastic at lower temperatures, and deformation under pressure can relax once the pressure is removed—much like an elastic band that recovers its original size when released. The effect of this elastic behavior is that the 3-D shape produced may become less precise at low temperatures. The pre-formed part will not fit into the mold accurately and may be damaged by the molding; or the film edges may not match the part edge accurately, leaving an undecorated area at the part line. We can see that high-temperature forming yields good shape conformance but poor print-to-form registration; low-temperature forming yields the opposite.

The optimum process differs from part to part. Processors tend to invest in one particular forming process, so be sure that the selected processor has the equipment suitable for the parts you wish to make. Let’s review the specific processes available.

High-pressure forming (HPF or Niebling forming) Niebling forming (Figure 1) was the first high-pressure process specifi-

HOT

HOT

HOT AIR UNDER PRESSURE

Flat film before forming

HOT

avoided in areas subject to significant stress in use—particularly part edges, where delamination can result. It is usually safe to use highly pigmented inks in the middle of parts.

Conduct aggressive adhesion tests on prints as a quality check.

However, it is not sufficient to specify tests on the printed part alone. The forming and molding processes add mechanical and thermal stresses to the part that can affect adhesion. Only stress testing of finished parts can give a definitive view of the durability of the construction.

Film formed to forming tool profile Forming tool

Figure 1 Niebling forming, or high-pressure forming, was the first high-pressure process specifically designed for film-insert molding. It is still the most popular method for manufacturing small to medium-size parts.

HEATED OIL-FILLED BLANKET UNDER PRESSURE Polyurethane blanket

Film formed under blanket Forming tool

Figure 2 The accuform process, while similar to high-ressure forming, uses higher pressures and applies force through a hot fluid medium behind a flexible membrane.

cally designed for FIM and remains the most popular choice for producing a wider range of small to medium-size parts. The film is preheated to a moderate temperature, usually somewhat above the softening temperature. Hot air is applied to the film under high pressure up to 300 bar, which exerts a lot of force. The larger the area formed, the higher the forces. The engineering required for large sheet sizes to contain the pressure becomes relatively expensive. Large-format machines are becoming available, but most machines on the market are designed around a form platen approximately DIN A4 in size. Cycle time tends to be about 30 seconds, so typically this process has a similar throughput cavity for cavity to injection molding (IM). Processors, therefore, need a similar number of forming machines as IM presses to handle a project.

Selvedge can claim a significant area of a sheet, and the cost of a tool bolster is relatively high, so inserts are usually made to fit a standard bolster. This means that the platen size tends to be fi xed and cannot necessarily be optimized for a specific part size. A standard platen may accommodate only a small quantity of parts, which means more sheet material is lost down the center of the JANUARY/FEBRUARY 2011 | 17

low heat and very high pressure

Male forming tool

Film formed with high pressure Female forming tool

Figure 3 Matched metal forming involves the use of hardened-steel tools that are heated and impacted on the film with great force.

Flat film before forming

Film formed to forming tool profile Forming Tool

Vacuum

Vacuum

Figure 4 Vacuum forming, or thermoforming, uses atmospheric pressure to shape heated films.

cavity and around the parts. Investigating alternate layouts may allow significant savings in material costs. Careful planning at the tool stage can have major cost benefits.

Accuform This process (Figure 2) is similar to the HPF process and uses even higher pressures, but the force is applied through a hot fluid medium behind a flexible membrane. This membrane, in contact with the film, gives good support, and the likelihood of sagging is low. Very good print-to-form registration can be achieved. The contact of the membrane with the first surface for the film can leave witness marks. This effect can be minimized or eliminated by introduction of a liner on the film’s surface. The liner must be chosen with care. The optimum material may vary from film to film and from one design to another.

The use of a fluid medium rather than air to apply force makes the engineering for larger platen sizes a little easier. The machines available can process sheets of about 18 x 24 in. (457 mm x 610 mm) in size. Cycle time is similar to Niebling, so again, throughput is similar to IM. Matched metal forming Matched tools made of hardened steel 18 | Industrial + Specialty Printing www.industrial-printing.net

(one male, one female) are heated and impacted on the film with great force. Matched metal forming (Figure 3) uses more pressure than other technique available and allows the use of the lowest temperatures. Protective foil is often used to minimize the damage caused by the contact made between the hard metal tool and the decorative front surface of the film. Typical equipment is relatively simple to produce, but it tends to be limited to small-area forming—usually single, small parts per cycle. Cycle time is fast, so output can be high and the economics attractive.

One low-cost machine can service several IM presses. The low temperature makes the registration good, but shape conformance can be very poor due to film elasticity.

Vacuum forming/thermoforming In this process (Figure 4), the film is heated to a very high temperature, well above the softening temperature, and then formed over a tool using air at atmospheric pressure. The force available is low. Because the pressures are low, this process is capable of forming very large sheets of film without the need for heavily engineered equipment. It may be the only process suited to large-format parts.

Remember that print-to-form registration is relatively poor and design accordingly, avoiding challenging tolerances. The shape conformance of the part is good, however, and very tight radii can be produced. The cycle time is similar to IM. Pack density This is one of the most important concepts in FIM. Pack density is the number of parts that can be made using a square meter of film material. It is the primary driver of the economic equation in forming. Clearly, the more parts that can be made on 1 sq m of film, the more cost effective the process. This is, however, a big caveat. Forming presses usually have limited platen size, so formable sheet size is also limited. The high-pressure and vacuum processes need a pressure-tight seal around the edge of the sheet, and this requires a significant selvedge around the formed area.

Controlling print-to-form registration often requires the subdivision of tooling to isolate one formed area from the next to prevent material being pulled laterally during the forming process. This, too, consumes valuable sheet area.

Draw ratio Draw ratio is defined as film thickness before forming divided by film thickness after forming. This ratio varies over the surface of a form profile. The most critical point is where the ratio reaches a maximum and the film is at its thinnest. Note that that this point of maximum draw ratio won’t necessarily coincide with the deepest area of the part profile.

The amount of film material available locally to form the shape required is another consideration not often visible on the finished part. The amount of material between one form feature and the next, or between a form feature and the clamp of the forming tooling, is an influential factor. Draw ratio also depends on the type of film used. Recall the thermo-mechanical properties of the various films discussed in the first part of this article.

Films with a bump in the stress-strain curve are easier to draw once the yield point has passed and will draw further. Films without the bump are more difficult to draw once the yield

point is passed, so areas not previously deformed will pick up the strain.

The draw for PC or PMMA (films with bumps) is concentrated in one area that then propagates outward as the draw continues. The draw ratio on this type of film tends to be higher. The draw for PET (with a bump) is distributed over a larger area, and the draw ratio tends to be lower at any given point. Note that in both cases the total elongation is the same; only the distribution of the strain is different.

Forming-tool design The following guidelines will help you optimize the design for your forming tools.

Maximize part radius. Avoid very small radii on the part. A very small radius at the bottom of a form dramatically increases the draw ratio at this point and may overstress the film. A very small radius at the top of the form may puncture the film.

Maximize pack density. Consider the number of parts that can be formed and molded per cycle from the flat film. Factors that influence this include the size of the forming and molding machine and the size and depth of part required. The greater the draw depth, the greater the amount of requisite film around each printed part to draw to the appropriate depth. As a rule, allow a minimum of 2 in. (50 mm) between each printed part on the flat film, but keep in mind the minimum distance required between parts varies depending on the draw, film type, and forming process used. For example, spacing should be five times the draw depth between parts and three times the draw depth from the outer part edge to the clamp when using films with limited forming capability. In most cases, spacings of four times the draw depth between parts and two times the draw depth of the outer part edge to the clamp can be achieved, but trials are essential to establish process capability on specific tooling and form processes. Using low-cost film can be a false economy.

Pack density is reduced when formability is reduced, and the amount of film required increases.

Avoid unnecessary draw depth. Determine the depth of the part and then design the forming tool to achieve this depth.

Excessive depth increases manufacturing complexity.

Exercise care in graphic placement. Try to avoid designing detailed text, logos, and graphics on areas of the film where the film will be drawn. Failure to do so leads to image distortion.

You should design these types of decoration for areas of the film that remain fairly flat. The area of film least likely to move is that which contacts the tool surface first during the forming operation. Note that this means that where graphics are required on the flat top surface of a part, such as a battery cover, the tooling really must be male. If a female cavity were used, the flat area would be the last part of the film to touch the tool and would be subjected to larger deformation and, therefore, misregistration.

Avoid first-surface contact between the film and forming tool.

Damage can occur to the film surface, potentially altering the gloss level at point of contact, when contact is made between what will be the exposed surface of the finished part and the forming tool.

Trimming A pneumatic press is usually the tool of choice for trimming, which is often completed after forming. Support of the formed material is critical in this stage to prevent damage.

Molding Molding is, in some respects, the simplest part of the FIM process. The use of film inserts does not affect machine specifications substantially. Cycle time is slightly increased compared to a non-insert-mold reference, so the capital investment cost is a little higher. The main consideration is not the machine, but the tooling. The key questions to ask are: • How will I insert the film into the tool?

• How will I hold the film in the tool?

• How will the film insert affect the melt flow?

• Will the melt flow damage the film or the inks?

• Will the film move as the melt front advances?

We have highlighted in these two articles the key stages of film-insert molding and related considerations. Specialty films are available, and widely used, that require additional care and attention in the processing stages to maximize their potential. FIM is now a widely accepted manufacturing process in the telecommunications and automotive markets and will see increased interest as functional switches are required in a molded part—and as these key industries look to simplify some of their components to gain significant cost savings and have access to a greater variety of decorative finishes.

neil bolding

MacDermid Autotype Inc. Neil Bolding has been employed by MacDermid Autotype for more than 25 years and involved in the printing industries for 30 years. He’s involved in customer-application support, regulatory compliance, quality management and product development support for screen printing and flexible electronics applications. He holds a bachelor’s degree in chemistry from London University and an M.B.A. from Roosevelt University, Chicago.

Jim Plamann

MacDermid Autotype Inc. Jim Plamann is the OEM program development manager for MacDermid Autotype. He is responsible for sales and project development for OEMs in the telecom, appliance, automotive, and medical-equipment industries.

Plamann has more than 20 years of experience in plastics-decorating/ manufacturing processes, including in-mold decoration, screen printing, membrane switches, and printed electronics.

Peter Warwick

MacDermid Autotype Ltd. Peter Warwick has worked for MacDermid Autotype for 20 years, more than 10 of which were spent working in the area of FIM. In his role as technical service manager for FIM products, he is responsible for supporting of existing products and evaluating of new products through every stage of the FIM process. january/february 2011 | 19

FEATURE STORY

A Look at

LARGE-FORMAT Pad Printing Julian Joffe

Pad Print Machinery of Vermont

Pad printing is an imaging process that can make easy work of products designed with irregular surfaces. Find out about technological advancements that make the method a match for large-format applications.

Figure 1 Shown here are examples of large-format pad printing used in the manufacture of keyboards and keypads for consumer electronics.

M

ost printers, when faced with a large-format print job, choose from a few popular methods—mostly digital or screen printing. Either choice is a suitable one when the substrate is flat and the images are composed of large areas of background color. Few engineers consider alternatives to the typical options, except when those processes will not work.

One such scenario is when the substrate is rough or undulating, or referred to as being three-dimensional in nature. In fact, they’ll often look for ways to manufacture the part flat then print and change it to the desired shape later, often going out of their way to avoid printing a compound surface. This option is expensive and unnecessary when a more convenient solution exits: pad printing.

We defi ne large format for the purposes of this discussion as items such as control panels for appliances, front bezels

on televisions, keyboards and keypads (Figure 1), and satellite dishes. The consideration for using pad printing as an alternative should be based upon the following considerations: • How large is the total image area?

• How many colors are to be printed?

• How much area does each color cover?

• Can the images be broken down into more manageable, smaller images that fit within the limits of the padprinting equipment?

• Are we dealing with large, solid areas of ink or realistic coverage that is broken up somewhat?

• How curved or uneven are the print surfaces?

Large areas of ink coverage are difficult to handle. In dealing with a single color, printing the part with a single hit using a

20 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net

large pad printer may be possible (Figure 2). Another way would be to break down the image and hit it many times to complete the image area. The same applies to a multicolor image. This option works, but it also decreases productivity, especially on single-color pad presses, which require multiple cycles to complete the printing. On the other hand, if a pad-printing machine that supports two or more colors or a servo-driven, CNC-equipped printer is used, the job can be completed in a single hit with a large pad or with multiple hits that occur in sequence during a single cycle of the machine.

Several advances in pad-printing equipment have been made to allow large-format printing to become an affordable and doable option. Advancements in pad-printing inks—from primitive, hand-milled pigments to inks that are formulated with better flow-control agents—allow adher-

Figure 2 (above) Propane tanks present the challenge of printing large areas of ink coverage.

Figure 3 (right) Pad selection and precise picking are among the automated features possible with multicolor, servo-driven, CNC pad presses.

ence to a variety of substrates with faster curing and durability. Pad materials have also been modified from a gelatin base to a high-tech, fast-curing, durable silicone material. Pads can now be designed and created in any shape and durometer to meet specific requirements.

On the other hand, the evolution from open-inkwell to sealed-cup systems has moved the industry slightly backwards in terms of the total image area available on a single cliche. The sealed ink cups are limited to a diameter of 10 in. and smaller.

One exception is the development of the cupslide, which uses a longer cliche, thereby permitting the image length to far exceed the cup diameter. With the use of a cupslide, images as long as 3-4 ft are possible with a single cliche and print pass. This technique has been used successfully in marking catheters for medical applications.

Pad-printing equipment and technology exists at its current level of sophistication due to advances in other technologies.

Pad printers have progressed from manual to motorized to pneumatic to servo-driven systems. The integration of computernumeric-control (CNC) servomotor technology was the single most important factor in making large-format pad printing possible. Servo-driven CNC pad printers (Figure 3) are able to select a suitable pad, step to the cliche area, and precisely pick up one of the multiple images from a polymer plate. The image being picked up could be a very opaque, white, solventbased ink or a UV-curable ink, depending upon the choice or requirements of the manufacturer. Large, hollow pads allow us

to pick up and print much larger images than we did as few as 15 years ago. Inks with better flow-control agents allow us to print smoother and larger surfaces of ink.

Pad printers can be designed with a row of independent pads, a conveyor system to move the parts, and cliches with multiple images etched. These systems can operate without limiting from where the images are picked or placed or in what sequence. The servo drive gives more flexibility in positioning and, coupled with independent pad systems, the ability to print an image wherever it needs to be printed. As an example, a pad printer can reproduce a 15-in. line using two 7.5-in. lines etched on a plate side by side and print both in perfect alignment.

A comparison can be made to the machine-tool industry in printing situations where the substrate needs to be decorated with multiple images of different shapes and sizes. A CNC machine can change cutting tools or drills mid-job, just as the pad printer can change from one pad shape to another. This process combines several single-color jobs into a single multicolor run.

Servo- and stepping-motor drives adopted in areas of tooling and fi xtures also facilitate the printing of large-format parts. Some situations require printing on more than one surface using the same image or a group of images. The creative use of this technology allows a part to be printed in one pass through the machine even though multiple sides require images.

Previously, if a large-format part were printed, smaller machines would be used and the part would have to pass through a

series of machines. Each machine would be responsible for decorating a part of the whole, thereby adding labor and space for moving and storing parts during the print operations.

The shuttle-type conveyor with its servo-drive is designed to add the extra axis needed to print large-format components with multiple images over a large surface area, while using sealed ink cups with diameters as small as 5 in. The servo drive on the printer gives the necessary positioning capability on the Y axis, and servo shuttle provides the positional control for the X axis.

Let’s not forget the one thing that binds all this technology together—the computer or programmable logic controller (PLC). Machines now run on industrial PCs, coupled to a PLC, integrating all of the automation. Some pad printers can now memorize production routines, repeat the job, and even recall all the critical settings so that there is a minimal amount of repeat work when setting up previous jobs. It is possible to network through an intranet where management can see at any moment how the machines are working in the manufacturing process.

ADVANTAGES AND CHALLENGES The advantages of pad printing are the ability to print a variety of applications with unique decorating requirements.

Uneven substrate surfaces (Figures 4 and 5) present little or no problem to malleable pads. Wet-on-wet printing is not an issue because of the limited amount of ink transferred to the surface and the quick drying capability of the inks. The cost of JANUARY/FEBRUARY 2011 | 21

Figures 4 and 5 Uneven surfaces are suited to the pad-printing process.

Shown here are appliance panels on press and finished.

producing the cliches in-house can be very reasonable and often requires a nominal investment in equipment. Pad printing is relatively simple to learn and implement, and four-color process is now commonplace with pad-printing equipment.

One major challenge associated with large-format pad printing is that large surfaces of ink coverage are difficult, and sometimes impossible, to deal with. The problem can be managed by using halftoned cliches to prevent scooping and using multiple hits to improve coverage. The multiple-hit option works, but it is costly in terms of production speed lost, particularly on single-color pad printers, which require multiple cycles to complete the print. Using a multicolor pad press speeds up the process of printing a one-color job that requires two or more hits to complete the image. Jobs put on multicolor, servo-driven, CNC pad printers may be completed in a single hit with a larger pad or with multiple hits during a sequence in the single-job cycle.

Large areas of solid ink do not print very evenly because the pad, to print well, rolls into the image. A properly designed pad generally has a wedge-shaped profile of a rooftop or mountain shape. The point of the pad applies more pressure on the ink’s surface than does the outer perimeter and, when picking up a large pool of ink, the point zone will usually displace the ink more than the outer area. This creates a

surface of ink that is uneven and, in many cases, will look like the surface of a pond with ripples emanating from the center.

The orientation of images on a cliche also plays an important role in whether or not scooping will occur. For example, if a 5- x 1-in. rectangle were positioned with the smaller edge perpendicular to the cup motion, scooping would be minimized.

On the other hand, if the cup were to cross the image at the widest dimension, scooping could occur, causing faded areas in the image. It would seem that rotating the image is a simple solution, but then the substrate needs to be rotated as well in order to orient the image correctly. In fact, it is no problem as head/pad rotation with servo control exists, and the image orientation on the cliche can be manipulated. The operator can save time by programming the head/pad rotation into the software. The rotating head is a great feature for preserving the registration of multicolor images.

The number of colors and the image area are important factors, as the size limitation of some multicolor pad printers may be as small as 8 in./color in diameter.

In the past, pad printing a large image was defined by the limitations of the machine’s cup/cliche size. The precision of modern, servo-driven equipment and the sophistication of the logic systems that control them allow the images to be broken into pieces and colors to be printed in separate

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hits. The greater the number of printheads on the press, the more efficient and precise the printing. Another solution for extremely large image areas is to use a pad printer that has the capability to print the part corner to corner.

Other printing challenges include jobs in which the overall size exceeds the traversing range of the conveyor or shuttle system holding the parts being printed. In these circumstances, the only option may be to reset the printer to have two separate passes to print the part. While this method is not the most economical, it will get the job done.

The flexibility that pad printing offers in decorating irregular surfaces not only makes this process an excellent complement to screen printing and digital imaging, but it also makes the technology an effective first choice. Advances in padprinter technology and accessories make large-format printing more accurate and cost effective. This technological evolution makes pad printing and exciting field.

Julian Joffe Pad Print Machinery of Vermont Julian Joffe is CEO and owner of Pad Print Machinery of Vermont (www.padprintmachin ery.com) East Dorset, VT. He has more than 30 years of experience in the pad-printing industry, including equipment engineering and machine design.

feature story

OLEDs Shine a Whole New Light on

Joseph Fjelstad Verdant Electronics

ake a trip to the main street of nearly any major town or city in the world at night and your eyes will be treated to a feast of light and color, flashing on and off, beckoning for your attention. Lighted displays came into existence soon after the development of the incandescent electric light bulb. The early versions were crude by today’s standards, but they were effective.

All that was needed was to create a pattern of light sockets, screw in the bulbs, and turn on a switch. These were augmented in the 1920s and 1930s up to the present by neon lights bent into shapes to form words and images in the night scene.

Actually, Edison’s idea of getting light on demand from electricity sparked the imaginations of many other inventors, scientists, and experimentalists who followed his exploits. One of note in the early part of the 20th century is Englishman Henry Round, who is credited with discovering electroluminescence in 1907, making the basic technology behind the light-emitting diode (LED) more than a century old.

However, it was not until the mid 1920s that O.V. Lossev demonstrated an LED in Soviet Russia. Unfortunately, there was no

apparent follow up, so the idea languished.

There was intervening development work on IR devices using the diode principle; however, the visible-spectrum LED did not finally appear on the scene until 1962 when Nick Holonyak invented the first such device, a red LED, earning him the title of Father of the Light-Emitting Diode. In the years that followed, small red LEDs began to appear in a range of consumer products, from wrist watches and hand-held calculators to alphanumeric displays for toys and games, but these simple applications gave no hint as to what was to come in the decades that followed.

OLED display technologies Since the birth of practical LEDs, their efficiency and light output have increased at an impressive rate—as have the range of possible colors. The fundamental attributes of efficiency and light output double approximately every 36 months and are now poised to overtake all other forms of traditional lighting in the not too distant future. This has not gone unnoticed by governments or the public and, due in part to legislative push and in part to consumer

pull along with the desire for more environmentally friendly solutions and energy savings, LED lighting (in combination with fluorescent lighting) is on it the way to obviating Edison’s venerable incandescent lamp.

However, when it comes to matters of light for those involved in the printing industry, the technology of greatest current interest in the area of organic light-emitting diodes OLEDs (see iSP, Nov./Dec. 2010, p. 22, “Bringing Opportunities to Light with OLEDs”). For reference and future appreciation of the terms of lighting, especially for displays, the unit most commonly applied to output is the nit. In lighting, the nit is a unit of visible-light intensity equivalent to 1 candela/sq m. It is a relatively small unit of light as one might be able to surmise from the basic definition and when one considers that a typical active-matrix LCD panel has an output between 200-300 nits. That aside, there are actually two major types of OLEDs, passive-matrix OLEDs (PMOLEDs) and active-matrix OLEDs (AMOLEDs). Of the two, passive matrix is most common and most practical in alphanumeric displays january/february 2011 | 23

One pixel (insertion of cathode and anode)

BASIC OLED CONSTRUCTION Glass or transparent flexible film Cathodes Light-emitting polymer

Figure 1 This illustration depicts the various layers and components necessary to build an OLED display.

Conductive polymer Anodes Glass or flexible film base

Red emitting polymer ink

Green emitting polymer ink

Blue emitting polymer ink

INKJET PRINTING OF COLOR-EMITTING SUB-PIXEL INKS

rather than high-resolution graphical displays. The latter is more the domain of active-matrix displays.

In a passive-matrix OLED display, the matrix of electrically conducting rows and columns forms a two-dimensional array of picture elements, or pixels as they are commonly called. Between the orthogonal column and row lines, in sandwich-like fashion, are thin films of organic material for the OLEDs. When a current is applied to the designated row and column lines, the OLED pixel is activated and emits light.

The basic structure of an OLED is illustrated in Figure 1. The individual pixels are defined by the intersection of anode and cathode conductors, which are fired and refreshed at high data rates. The brightness of each pixel is proportional to the amount of current applied to the OLED of the pixel. While PMOLEDs are fairly simple structures to design and fabricate, PMOLED displays are typically limited to fewer than 100 lines for a number of technical reasons. In addition, their power consumption is significantly higher than that required by an active-matrix OLED—a point that is increasingly

Figure 2 Shown here is the fundamental process of inkjet printing OLED components.

important in the ongoing effort to reduce power use and/or extend battery life.

Active-matrix OLED displays comprise organic light-emitting-diode pixels that have been deposited or integrated onto a thin-film transistor (TFT) array, forming a matrix of pixels that emit light upon electrical activation. In contrast to PMOLED displays, where electricity is distributed row by row, the active-matrix TFT backplane acts as an array of individual switches coupled with sample-and-hold circuitry that controls and maintains the amount of current flowing through each individual OLED pixel during the total frame time. Thus, the active-matrix TFT array continuously controls the current flowing to the OLEDs in the each of pixels and can signal to each individual OLED how brightly to light up. This offers a tremendous advantage in terms of contrast and performance and provides ample evidence as to why active-matrix displays are on the rise.

DRIVING DOWN COST The manufacturing equipment and materials technologies that have been brought

24 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net

to bear on the challenge of OLED-display production have helped to drive down costs while improving quality. Leading the charge has been the development of organic semiconductor inks by well known materials developers, such as DuPont and Dow Corning, that can be printed using a range of different printing technologies—inkjet technology included—to print colored, light-emitting materials. Equipment companies such as Fujifilm and Xaar are addressing this growing opportunity. Figure 2 illustrates fundamental processing.

Inkjet technology plays a key role in the production of color displays in the printing of the color-emitting inks that make such structures possible. A recent report suggests that DuPont has developed materials and processes that allow for the production of 50-in. printed OLED TV displays in less than two minutes using their materials and a new printing technology. If this development plays as hoped and can be scaled up in terms of manufacturing, the total cost of OLED TVs would obviously be greatly reduced. The developer team also submits that displays made with the technology and operated during

Figure 3 Sony’s flexible OLED display can be rolled and unrolled more than 1000 times without loss in image quality.

a typical eight-hour day every day could possibly last up to 15 years. This development actually helps stage an important feature of printed organic-polymer OLED structures: they can be fabricated on thin, flexible films, thereby making roll-to-roll processing possible. Moreover, it opens the door to applications that are yet to be imagined by tomorrow’s engineers and product developers.

Figure 3 shows an example of a flexible display from Sony. The display, which is capable of displaying still images and video and can be rolled up while content is still playing, is slightly more than 4 in. and 432 x 240 pixels and has a curvature radius of just 4 mm. Sony engineers report that, even after rolling and unrolling the display 1000 times, there was no apparent damage to the quality of the display.

A growing market opportunity OLEDs are making impressive strides to change the rules of display technology.

OLEDs are being used to make highdefinition displays, and displays like those shown by Sony are so thin as to have been largely unimaginable by practicing engineers just a decade or so earlier than today. Due, at least in part, to this important feature, there is a large and growing demand for OLED-display products in an ever-expanding range for products.

According to various market-watching sources, the global OLED market is expected grow to somewhere in the range of 350 million units in the next few years, which translates to about $5 billion of the nearly $95 billion market for displays.

The compound annual growth rate for OLEDS is somewhere near 25% at present, compared to the total market, which is expected to grow at about a 4% rate. For comparison purposes, inorganic TFT LED displays enjoy a nearly 85% share.

PMOLEDs made up almost 90% of the total OLED market among OLED-display types as recently as three years back; however, as mentioned earlier, because of their important advantages, AMOLED displays are expected to enjoy a much higher growth rate. As for materials, the recent report “OLED Lighting Materials Market Trends and Impact” from industry watcher NanoMarkets indicates the market for materials used in OLED lighting will be around $1.4 billion in 2015, which will represent about 20% of the total OLED market at that time.

The applications for OLED displays are numerous and give credence to the projections. Presently, active- and passive-OLED displays can be found in many applications, including automotive instruments and GPS displays, industrial controller displays, medical monitors and diagnostic tools, home appliances and white goods, in

and outdoor advertising, telecommunications, and handheld devices of every sort, and, of course, small-and large-format televisions. In truth, this brief listing just scratches the surface of potential uses for OLED technology.

Summing it all up OLED is an impressive technology that offers capabilities that cannot be had by any other. With a constant flow of new materials, equipment, and manufacturing technologies to improve the technology and help drive down technology costs, OLED display technology is poised to take on a broad range of display challenges in the very near future. The technology that underpins the entire effort is printing. Those in the printing business should know that their skills and capabilities are secure even as the form of the printed word changes shape.

Joseph Fjelstad Verdant Electronics

Joseph Fjelstad is a 34-year veteran of the electronics-interconnection industry and is an international authority, author, columnist, lecturer, and innovator who holds more than 150 issued and pending U.S. patents in the field. He is the founder and president of Verdant Electronics and co-founder and CEO of SiliconPipe. He has also worked with IC-package developer Tessera Technologies. january/february 2011 | 25

FEATURE STORY

W

Sticking with Printable Adhesives Lisa Krueger Castillo KIWO, Inc.

This article describes the characteristics of print-applied adhesives and discusses their use in industrial applications.

Transfer tape on a part Photo courtesy GM Nameplate

26 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net

hen it comes to printing adhesives, does one size really fit all? The honest answer is no. In printed electronics, there are many places where a printapplied adhesive is the right choice. In the middle ground, there are numerous applications where either print-applied or transfer tape adhesives can be used.

In a membrane switch, for example, print-applied pressure-sensitive adhesives (PSAs) are used to bond the overlay, bond different layers, and for bonding the membrane switch to substrates and housings.

The key advantage of transfer tape is that it is ready to use and the adhesive performance is predetermined, in that a given PSA formula is coated to a consistent thickness, smoothness, and cure. Once you’ve selected the right formula to fit the intended conditions or specifications, only verification, compatibility testing (to component layers), and processing remain. The transfer tape is die cut before transferring, and the less surface area to be covered by the adhesive, the greater the waste matrix. The more intricate the pattern, the more difficult to hand position onto the part, with expensive labor, tooling, and waste (Figure 1).

The beauty of printed PSAs is that they can be printed in virtually any shape or zone without waste or need of die cutting or tooling. Additionally attractive is that adhesive performance can be manipulated by the printer, through deposit thickness, smoothness, and even by subjecting the dry adhesive to slightly elevated temperature, for a given time, in a batch oven (Figure 2). They are more economical than transfer tape, not only in thousand-square-in. (MSI) pricing, but also in exponentially reduced waste because there is no weeding of die-cut waste.

A HISTORICAL OVERVIEW OF PRINTED PSAS Pressure-sensitive adhesives have been around, in various forms, for most of our lives. Pressure-sensitive tapes were created in the 1930s, and Stan Avery is widely credited with inventing the first adhesivecoated label in 1935.

In 1978, Kissel & Wolf GmbH was the first to make screen-printing-applied PSAs, together with industrial partners, to meet the temperature extremes and environmental conditions in the automotive and nameplate industries. These adhesives had to flow out, dry to a smooth surface, and stick aggressively when bonded. The early printable PSAs were solventbased adhesives with synthetic rubber polymers. They were later based on acrylate polymers. High-performance, water-based acrylate polymers were in use by the beginning of the 1990s.

The inquiries and applications soon grew to encompass electronics, including sectors of the printedelectronics market, such as consumer-oriented products, hand-held electronics, medical controls, and

more. These markets are served with water-based, solventbased, and UV-curable print-applied PSAs. DESIGN FREEDOM OF PRINT-APPLIED PSAS You can print single dots, dot patterns/groupings, and fine lines, down to approximately 1.5-2 mm (60-80 mils) wide.

This freedom of design is put to good use in some switches to move or channel air out of the way during activation.

The air movement can be put in the spacer, or even in the adhesive.

As far as issues such as edge ooze, it really depends on the formula. The in-dustry’s safe approach is to bleed the pattern away from the edge. And, in terms of bleed-through,

Figure 1 (top) The transfer tape is die cut before transferring.

Figures 2a and 2b (bottom) Print-applied pressure-sensitive adhesives (PSAs) are used to bond different layers and for for bonding membrane switches to substrates and housings.

2a

2b

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industrial-printing.net JANUARY/FEBRUARY 2011 | 27

24 hr dwell 1 min dwell

25 20 15 10 5 0

20-300 25-260 Mesh (threads/in. - micron thread diameter) Figure 3 (left) Different adhesive force, with the same adhesive, but different mesh Figure 4 (right) Squeegees are the heart of the printing process.

it depends on the formulation and the chemical form of the ink. Bleed-through can happen, so it’s important to use a special adhesive that does not contain any migratory content. Like transfer tapes, once you’ve selected the formula, to fit the conditions, only verification, compatibility testing, and pro-cessing remain.

Selecting and defining limits of print-applied PSAs One consideration is adhesive type. Match the adhesive formula to the climate and temperature extremes typical in the service life, transportation, and storage of the part you’re making. In the screen-printing industry, the common choices are: Acrylic adhesives These have the broadest temperature range, due to the lower glass transition Tg (the phase transition from viscous liquid to glass). They resist aging, and some formulas have excellent resistance to combined high temperature and humidity, even water immersion.

The two types are water based, which typically handle -40°C/F up to 350°F (or higher), and solvent-based, which typically handle -20/-40°C to 60/ 80°C or -4/-40°F to 140/176°F. Rubber adhesives These are normally synthetic rubber and stick to most things.

They exhibit very high initial tack, peel strength, and humidity/moisture resistance with medium temperature resistance (-20/ -30°C to 82°C or -4/-22°F to 180°F).

UV-curable adhesives These are attractive for processing speed, ease, and for being complete systems. UV-curable PSAs can have excellent moisture resistance

with moderate temperature resistance, typically -30°C to 85°C or -22°F to 95°F. They have good peel strength, though they are not yet equivalent to higher performance tapes and print-applied PSAs. The newest developments aim toward complete UV-curable systems, making rapid drying possible even in thicker layers, to achieve increased productivity. The 100%, or complete, systems give hope for the best production possibilities and already show considerable conversion.

Bond surfaces and substrates involved are other key considerations. It’s easy to find an adhesive’s peel strength and general compatibility to various plastics and metals. The part thickness, contour, porosity, and roughness are critical considerations because they can have an affect on the bond by inherent stress. For example, a thick, self-adhesive part, bonding to contoured housing, has to have a high-tack adhesive of good thickness and strength to prevent pop-off or failure after installation. When sufficient pressure is applied, the adhesive’s flow, tack, affinity for the substrate, and cohesion (internal strength) have to overcome the memory of the thick substrate to achieve wet-out and maintain adhesion to the contour of the housing.

Adhesion is the force that holds these substrates together against all the stresses exerted to pull them apart. If the adhesive were to separate from the substrate, or the adhesive itself break apart, the bond would fail. The bond performance of print-applied PSAs is greatly influenced by processing (Figure 3).

Printable PSAs are simply printed, to

28 | Industrial + Specialty Printing www.industrial-printing.net

the intended thickness, like another layer of ink. Actual PSA printing strongly resembles printing with inks, and the screen-printing equipment used is essentially the same. The screen-printing stencil and the printing and drying process parameters differ from that of standard graphics and technical screen printing.

Printable PSAs are usually ready for use; although, in some special cases, solvents, anti-foaming agents, wetting agents, and dyes (for visibility) are available for use with them. The main difference from printing ink is the use of very coarse screen-printing mesh because thick deposits of adhesives are often necessary.

As with tape, thicker adhesive is stronger. The limit thickness of print-applied adhesives is 150-160 μm (6.4 mils) of dry adhesive. Above this, one would have to use tape. While dry-adhesive thickness of 4-6 mil is sometimes used in the wet white goods sector of printed electronics, dry thickness of 2 mil (50 µm) is more the standard target for print-applied PSAs. A 54-thread/in. mesh with 140-μm thread diameter is commonly used to reach approximately 2 mil dry thickness for most high-solids, high-performance water-and solvent-based printable PSAs. UV-curable printable PSAs use slightly finer mesh, as low as 92 threads/in. and 90-μm thread diameter and finer. Label and decal applications are applied with mesh beginning as low as 195 threads/in. and 55-μm thread diameter. Some graphics applications and repeatedly removable bondings can have adhesive thicknesses between 10-15 µm. The mesh charts of the manufacturers contain the theoretical ink volume as a reference point for the adhesive volume that can be printed (Figure 3). This diagram shows the different adhesive force, with the same adhesive, but different mesh.

Mesh specifics Most companies choose polyester mesh over stainless steel because of lower cost and reduced wear on the squeegee. Those that choose stainless steel do so because it offers thinner wire and greater stability of screen tension. This may be an advantage, in extreme cases, providing improved smoothness.

For these coarse meshes, select an emulsion that is made to coat 1:1 or 2:2, without dripping, and that works with the

adhesive system you chose: water, solvent, or UV-curable. Emulsion coated on coarse mesh requires more drying time before exposure and a post exposure to the squeegee side for best resistance. Your emulsion manufacturer will be glad to help you.

The sheer variety of press types (flatbed and rotary), meshes (polyesters or stainless steel), and other parameters requires on-site optimization, off-contact, squeegee pressure, squeegee angle, and drying (air, IR, NIR, UV). Aside from the mesh, the squeegee is at the heart of these printing parameters (Figure 4). In general, I like the idea of the even pressure supplied across the screen by the hingedsqueegee concept. I look forward to further testing with it and print-applied PSAs. The increased speed that it touts would increase production tremendously while putting more pressure on drying.

Drying a print-applied PSA is critical to achieve full adhesive strength. One particular dryer manufacturer has moved to increase speed of the drying process. With glass frit inks, UV curing PSAs, and for a conductive, drying/cure rates were increased in the area of two to three times the speed compared to traditional systems. What the figure could be with a water-based print applied PSA is yet to be determined.

Occasionally, there are special challenges during printing, such as when the adhesive will not print to the edge of a circle or die-cut hole. In this case, it’s beneficial to use a more rigid squeegee that is sharpened to get a wedge/angle on its blade. This serves to print more adhesive than the cell would normally hold. The bottom line is good process controls and QC will maintain the repeatability.

systems and, not surprisingly, continues with water-based acrylic formulas. The industry is trying to use print-applied PSAs as spacers.

For the moment, the best use of print-applied PSAs in membrane switches is for bonding of different layers and for bonding the membrane switch to substrates and housings.

Lisa Krueger Castillo KIWO, Inc

Lisa Krueger Castillo is the industrial-adhesive product manager for KIWO (Kissel + Wolf), a manufacturer of chemical products for screen-making and specialty adhesives. She has been involved in technical marketing and sales capacities in the screen-printing industry for two decades. Her articles have been published domestically and internationally, primarily through Screen Printing magazine. She holds a bachelor’s degree from California University of PA and a master’s degree from Clemson University.

Contact her at 1-800-KIWO-USA or la.Castillo@att.net.

Conclusion The ever expanding printed-electronics market is using print-applied PSAs. Focused interest remains on 100% UV-curable january/february 2011 | 29

FEATUE STORY

SGIA EXPO 2010

Find out about the future of industrial printing and learn about some of the products on display at SGIA 2010.

in Review Photo cour tesy of Darek Johnson

T

he 2010 SGIA Expo in Las Vegas, NV, held October 13-15, was a record-breaking event, according to the Specialty Graphic Imaging Association. The total number of registrants, nearly 22,000, set a new record for SGIA. There were more than 480 companies exhibiting on the show floor, occupying more than 180,000 sq ft.

This year’s show featured the Industrial Application Zone, a section set aside for industrial printers and for viewing the-stateof-the-art processes used to produce high-tech products. Many of the same exhibitors there were also on the main portion of the show floor; however, for the first time, products such as medical sensors, automotive decorative parts and panels, membrane switches, and printed circuit boards (PCBs) had a place in thet annual event.

THE FUTURE OF INDUSTRIAL AND SPECIALTY PRINTING While traveling around the whole show floor, we asked exhibitors for a look into the future for industrial printers. At present, the industry seems split into many areas. A little interpretation of where it is going gives perspective. Here are a few of their predictions.

FRED ROSENZWEIG, PRESIDENT EFI We see the need for digital industrial applications and specialty printing applications growing in the marketplace. The new ability 30 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net

to provide graphics on many substrates opens up this marketplace.

As digital printing continues to get faster, the break-even crossover point for digital solutions for industrial applications will grow. This market is an emerging and exciting space.

EMMA K.R. SCOWEN, INDUSTRIAL PRODUCT MANAGER MACDERMID AUTOT YPE LTD. Customers are looking for increased efficiencies and to eliminate process steps. For instance, film-insert molding (FIM) is one technique designed to decrease process steps. It’s used a lot in Europe, but is just beginning to grow in importance in the U.S. ANDREW ORANSKY, DIRECTOR OF PRODUCT MANAGEMENT ROL AND DGA CORPORATION By keeping equipment flexible, we can incorporate many processes in one piece, thereby controlling costs for printers. Also, if a printer—or even a manufacturer—wants to be successful, it’s important not to define yourself in an extremely narrow niche.

MIKE YOUNG, PRESIDENT IMAGETEK CONSULTING INT’L This year’s SGIA Expo spoke volumes of industrial screen printing as a soaring fabricating process of choice, due to its absence—notwithstanding the Industrial Zone. While sounding like an oxymo-

ron, the statement is supported by the fact that more consumables are being shipped to the screen-printing community, both in volume and in value, against the backdrop of less activity in the commercial arena.

Varying estimates suggest the industrial sector could be as much as 20 fold the current commercial marketplace—not exactly small pickings to leave out in the cold!

But where do these seemingly invisible industrial printers go for their shot in the arm with technology, supplies, and processing technique updates? The highprofile Industrial Zone at the Expo was exceedingly refreshing to see and certainly welcomed, but much more has to be done if we want to embrace the hundreds, if not thousands, of industrial in-plant printers into our fold.

On that train of thought, I believe the Industrial Zone could, in the future, be used as a perfect launch pad to embrace other industries, where the process of screen printing is used abundantly in the manufacturing/fabricating world—inevitably, where the finished print or coating becomes the heartbeat of the final product.

The question is how does one connect and attract these industrial in-plant operations so they can embrace both a specific trade association and enlightening conventions that are geared explicitly to their needs.

They would learn a great deal simply by stepping outside of their proverbial enclosed box and be updated continuously with newer products, suppliers, ideas, and techniques that will immensely enhance their respective endeavors and well being.

One can be assured that the guys taking care of heating, cooling, and ventilation of large hotels do not attend Hotel, Resort, and Vacation Expos, but rather those designed specifically for their professions.

The gloves are off and the challenge is on: How do we best tackle the situation to outreach and get these industrial printers from out of the woodwork? No doubt the answer is staring us in the face but hidden due to the trees. I did hear form an undisclosed source that attempts in this direction are in the works, but I think the most influential live-wire to achieve this objective is thorough suppliers—the very people that end users come to see at such event Moreover, perhaps SGIA could set up a separate entity specifically to seek out

these unseen, but extremely prominent, practitioners of the screen process that one does not typically find along Main Street or listed in the Yellow Pages, so the whole screen-printing community can become richer and more distinguished by default in larger numbers.

Ryan Moor, President Ryonet Corporation I think that fashion will dictate simpler, smaller prints, less color, and cleaner designs. Look at what Apple is doing for computers, iPads, and their image overall. It’s clean and simple, but very hip.

Dayton “Joe” Deetz, President Visual Magnetics, LP Specialty and industrial printing is a broad field. Many aspects of this niche will continue to flourish with advances in print technology and tend to stay stateside, where other sections of this sector will find haven overseas, whether China or Italy. Many of these customers are so price conscientious that it will not take too much to send them abroad.

Manufacturing firms in industries such as ceramics, solar, and digital label presses are utilizing industrial digital inkjet already. Other industries with products suitable for industrial digital are automotive, medical, sporting goods, ad specialty, consumer goods, electronics, apparel, glass, and many more. Digital is here.

Ben Reutter, Business Development Manager Transfer Express, Inc. I expect more automation and more digital printing. I expect industrial and specialty printing to get even more specialized. With so many media/carriers available, it’s no longer one-size-fits-all.

Manufacturers will have different media available for specific functions and will have more choices available.

Products for Industrial Printers Promoted at SGIA The companies and products listed below represent a cross-section of industrial-oriented technologies on display at the SGIA 2010 Expo.

Bayer Material Science—Films Unit

Sigi Knappik, Manager of New Business Development ITW Trans Tech Industrial and specialty printing will con-tinue to grow at an increased pace and evolve. One of the primary drivers of the increased growth is the ability to digitally print directly onto a product in full, four-color process at productionline speeds. The technology is making analog equipment and processes obsolete.

Industrial digital is cleaner than analog processes and environmentally friendly as well. Digital is also creating new marketing opportunities for companies because of the vast options now available.

Cost per print is being driven down dramatically at time when graphical capability is increasing. In addition to printing full, four-color-process, highend imagery, barcoding or lot-code numbering can also be incorporated into the print. Every print is essentially an original. This type of decoration can be incorporated into existing manufacturing processes with single-pass or flatbed-style printers to minimize production costs.

promoted its line of polycarbonate films, Chemical Resistant, Weatherable, and other specialty films.

Douthitt promoted its CTS Digital Screen Imager. The system, available in three formats, is designed to eliminate film-based stencil making and streamline prepress for screen printing.

Dynamesh focused on V-Screen mesh, woven from VECRY-based monofilament thread. It is engineered for high strength, low elongation, improved chemical resistance, and water-repellant characteristics.

EFI showed its Jetrion narrow-format UV label-printing solution.

FLEXcon emphasized its polymeric materials technologies, including barrier films, optical hardcoats, roll-to-roll films, laminates, and custom solutions for electronics applications.

Gerber showcased its CAT UV, a wideformat inkjet printer that features the company’s Cold Fire Cure technology for imaging directly onto a variety of materials, including heat-sensitive plastic, vinyl, fabric, and paper-based materials. The company also highlighted the M Series Turbo flatbed cutting table. january/february 2011 | 31

Heraeus Amba/Heraeus Noblelight made UV-curing and metal-halide lamps for industrial applications the focus at its booth.

The company’s lamps may be used in the manufacture of graphics and packaging, labels, circuit boards, decorated metals and glass, inkjet printing, adhesive curing, and more.

INX Digital showed the Evolve DCP100, a four-color (CMYK) an inkjet printer designed for printing on two-piece coated or uncoated aluminum cans. It features a UV LED curing system. The company also introduced Triangle EDX ECO ink, an eco-solvent formulation.

ITW Trans Tech highlighted the InDecs direct-to-substrate UV inkjet printer. The modular system uses a six-color ColorBond inkset (CMYKW+Clear) and supports imaging resolutions up to 360 dpi (900-dpi apparent). Print width is expandable in increments of 2.1 or 2.7 in. (53 x 69 mm).

The system features inline UV curing and ink pinning and prints at speeds of 10 in./sec (254 mm/sec) or more. It accepts the optional QuickFix tooling-tray system, vacuum table, and other parts-handling solution. Control is via a Windows XP-based system with custom graphic user interface.

Marabu focused on its new UltraSwitch UVSW UV-curable screen ink and Maraswitch MSW solvent-based screen ink for membrane switches. The inks can be used separately or together in the same application. They’re formulated for very good multilayer adhesion in full-area prints, elasticity and excellent post-processing, high peel-off, opacity, and more. The company also showed Ultraglass UVGL and Ultraglass UVGO, both of which are UV-curable inks for glass. The heavy-metal-free formulations are designed to resist dishwashing, alkalines, and scratching.

Mimaki highlighted the UJF-3042, a tabletop-format inkjet printer designed to image directly onto a variety of materials.

It features UV LED curing, simultaneous white over and under printing, a six-color inkset, and clearance for media up to 1.97 in. (50 mm) thick. The system supports variable data.

Norcote emphasized its IM Series NVP-free in-mold-decorating system. The inks are formulated for excellent opacity, flexibility, and gate-wash resistance. IM Series inks do not require the use of a tie-coat. Norcote says the system delivers

a very durable and abrasion-resistant ink film after forming and molding.

Nicomatic promoted its CrimpFlex Connector System; SwitchAir Non-Stick Metal Snap Domes, designed for use with pick-and-place machines; Ultra-Thin SMD LEDs, designed for the membrane-switch industry; and more.

Owosso Graphic Arts promoted its brass, copper, and magnesium dies for hot stamping, thermal kiss-cutting, overlay embossing, custom applications, and more.

OYO Instruments promoted its thermal films, designed to support creation of positives and negatives at resolutions up to 1200 dpi, as well as its direct-toscreen systems, which are engineered to work without the use of inks, toners, or chemicals.

Pad Print Machinery of Vermont put the spotlight on its XD070, an inkjet printer designed for multicolor printing on flat and semi-flat surfaces. Features include support for variable data; continuous, multicolor printing in a single pass; integrated RIP; print speeds up to 16 in./sec (406 mm) at 360 dpi; support for printable items up to 12 x 12 in. (305 x 305 mm); automatic height detection; optional automatic parts handling, pre-treatment, and vision systems; job queuing; and more.

Proell spotlighted its NoriCue MPF, a UV-curable screen-printing ink designed for deep-draw applications. Proell says the inks show good adhesion to a wide range of substrates, can be drawn to 350% without color variation, and cure quickly.

The inks are NVP-free. The company also showed its Mirror Ink series, which includes M1, a high-gloss formulation; M2, designed for scratch resistance after jet drying and available in eight colorants; M3, developed for highest gloss, easy processing, and excellent resistance to humidity; and FSI, formulated for first-surface applications.

Richmond Graphic Products promoted its SolarBeam DirectJet screen-exposure system, designed to create stencils from screens imaged on CTS systems, as well as the DirectJET Pro computer-to-screen system, engineered to use UV-blocking inks and equipped with Z-axis motion for printhead protection.

Roland showcased its VS Series VersaCAMM wide-format inkjet printer/cutters. They feature three Eco-Sol Max ink

32 | Industrial + Specialty Printing www.industrial-printing.net

configurations (CMYKLcLm, 2 x CMYK, CMYKLcLm+Silver+White) and are available in 42-, 54-, and 64-in. (1067-, 1372-, and 1626-mm) models. Each supports maximum imaging resolution of 1440 x 720 dpi and offers cutting force/offset of 30-300 gf/0-1.5 mm. Maximum print speeds are 248, 228, and 125 sq ft/hr for the 64-, 54-, and 42-in. models, respectively. Maximum cutting speed is 11.8 in/sec (300 mm/sec) for all models.

SaatiPrint USA promoted its mesh, chemical emulsions, frames, stencil films, Bopp wire cloth, Duralife squeegees, screen inks from Dubuit and Marabu, and more.

Screen USA showcased its Truepress Jet2500UV, a hybrid inkjet printer that accommodates rigid media up to 98.4 x 51.1 in. (2500 x 1300 mm) and roll-fed media up to 164 ft (50 m) long. It supports imaging resolutions up to 1500 dpi and print speeds up to 72 sq ft/hr (67.5 sq m/hr).

Truepress Jet2500UV prints a four-color (CMYK) inkset. Light cyan, light magenta, and white are available as options. Other options include additional print table, battery box, cart for roll media, signal tower, and guide for corrugated cardboard.

In conclusion Industrial and specialty printing is becoming a greater part of many printing and electronics shows. This year, for the first time, the IPC introduced a new conference in printed electronics in Irvine, CA, this January. The FlexTech Alliance will sponsor an ever-growing Flexible Electronics and Display Conference in February this year. The SGIA’s Printed Electronics and Membrane Switch Conference has enlarged each year in exhibitors and attendees.

IDTechEx has conferences worldwide specifically covering printed electronics and photovoltaics. SEMI covers the subject each year during SEMICON West.

Most of the conferences are held in the West and Southwest near the semiconductor production areas in the U.S. As the world demands smaller, faster, cheaper products with more functionality, industrial and specialty printing will respond accordingly, and we predict that these conferences will grow in popularity.

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Market movements and association updates

INDUSTRY NEWS

Northeast Ohio: Mecca for Flexible Electronics?

NorTech, a regional, nonprofit, technology-based, economic-development organization, announced the completion of a shared vision and action plan to accelerate the growth of Northeast Ohio’s emerging flexible-electronics industry. The global electronics industry demands small, low-cost devices that consume less power with more functionality that are integrated into a consumer’s everyday life, including apparel and mobile devices. The flexible-electronics industry has emerged to address that demand. According to the International Electronics manufacturing Initiative (iNEMI), the global flexible-electronics market is estimated to grow to a $250B by 2025.

NorTech lead the strategic roadmapping process in partnership with 23 technology and industry experts from Northeast Ohio research institutions, manufacturers, materials suppliers, and product developers. The roadmap outlines strategies for developing low-cost manufacturing of electronic devices printed on flexible materials for multiple global market applications.

During the process, participants set a vision for the state to become an epicenter of flexible-electronics innovation and manufacturing. The ultimate goal is to add 1,500 jobs, $75M in payroll, and $100M in capital to Northeast Ohio by 2017. The brand name FlexMatters has been adopted to identify the Northeast Ohio cluster of interconnected businesses, suppliers, service providers, and associated institutions with the flexible-electronics industry. FlexMatters has gained recognition and support from the federal government, Ohio’s Third Frontier Program, as well as regional philanthropic and economic organizations. In September, FlexMatters gained a $500,000 grant from the U.S. Small Business Administration Innovative Economies initiative. For more information, visit www.nortech.org.

upcoming events Jan 18-19 IPC Conference on Printed Electronics: What Does It Mean for the Printed Circuit Board Industry?

Irvine, CA. www.ipc.org/printed-electronics Feb 7-10 FlexTech Alliance: Tenth Annual Flexible Electronics and Display Conference Phoenix, AZ. www.flexconference.org

APR 3-7 IDTechEx Printed Electronics & Photovoltaics Europe.

Dussledorf, Germany. www.idtechex.com APR 12-14 IPC APEX Expo, Las Vegas, NV. www.ipc.org

34 | Industrial + Specialty Printing www.industrial-printing.net

May 24-27 FESPA Hamburg, Germany. www.fespa.com

July 12-14 SEMICON West IPC San Francisco, CA. www.ipc.org

June 14-16 SGIA Printed Electronics & Membrane Switch Symposium San Jose, CA. www.sgia.org

Sep tember 27-28 RFID Europe IdTechEx Cambridge, UK. www.idtechex.com

FDC and AUO Partner to Drive Flexible AMOLED Work

Rice Uses Graphene for Single-Transistor Amps

Tempe, AZ-based Flexible Display Center at Arizona State University and Au Optronics (AUO) will collaborate on the development of mixed-oxide thin-film transistors to accelerate the commercial availability of active-matrix organic light-emitting diode (AMOLED) flexible displays. AMOLED displays have already begun to gain market traction in conventional glass displays for smart phones because of the vibrant colors they deliver. The partnership will focus on bringing the benefits of AMOLED displays, including full-color, full-motion video to flexible displays.

“The FDC has significant experience in adapting standard flat panel display manufacturing technologies for use with flexible substrates, which is a critical aspect of being able to bring flexible AMOLEDs to market,” says Yong-Hong Lu, VP of AUO Technology Center.

AUO and the FDC will work in active partnership with dedicated engineering teams to advance mixed-oxide transistor technology and the handling capabilities of conventional flatpanel-display manufacturing processes to accommodate the thin, plastic substrates used for flexible displays. Mixed-oxide TFTs offer a better ability to drive currents and improve the lifetime and stability of transistors used for OLED displays.

“As one of the leading FPD manufacturers in the world, AUO brings significant expertise in AMOLED display technology and manufacturing,” says Nicholas Colaneri, director of the Flexible Display Center at ASU.

Research at Rice University uses triple-mode, single-transistor amplifiers based on graphene and could prove to be a game changer for future electronic circuits.

Kartik Mohanram, assistant professor of electrical and computer engineering at Rice, is collaborating with researchers at the University of California, Riverside on a three-terminal, singletransistor amplifier made of graphene. The amp can be changed during operation to positive or negative carriers on the fly, depending on the input signal. The three terminal, single-transistor amp made of graphene can be changed to one of three modes depending on the use of carriers that are positive, negative, or both. It is ambipolar, allowing current to flow when a transistor is open in either direction around a point of negative contact. With a single transistor that could function in three different modes, the possibility of replacing many transistors in an integrated circuit becomes an interesting possibility for researchers.

In October 2010, Andre Geim and Konstantin Novoselov split the Nobel Prize in Physics for their work on carbon-compound graphene. Graphene is a single-atom-thick sheet of carbon atoms.

Arrayed in a honeycombed pattern, graphene is said to be the strongest material discovered, though it remains flexible, conducts electricity better than silicon, and resists heat. (For more information about graphene, see “Developments in Conductive Inks” by Sanjay Monie, Ph.D., iSP, May/June 2010, p. 28.)

IPC Lists Top Ten Trends LED Backlight Penetration Research conducted by IPC (Association Connectin LCD TV Panels reaches ing Electronics Industries) indicated the top ten 26% in Q3 of 2010 technology trends to watch in electronics manufacturing, including:

1. Miniaturization 2. High performance 3. High-density interconnect 4. Embedded technology 5. Flexible circuits 6. Lead free 7. Halogen free 8. Light-emitting diodes 9. Optoelectronics 10. Printed electronics

Industry experts and executives at printed-circuit-board manufacturers, electronics-manufacturing-services companies, and original equipment manufacturers, as well as suppliers of materials and equipment to those industries, contributed their views on the trends, time horizons, and potential impact of these trends. The white paper is available for download at www.ipc.org/tech-trendswhite-paper.

DisplaySearch reports that shipments of large-area TFT LCDs larger than 9.1 in. fell to 163 million units in Q3 2010, with 4% Q/Q decline, but 7% Y/Y growth. Revenues reached $21.3 billion, down 7% Q/Q, but up 7% Y/Y. According to the latest Quarterly Large Area TFT LCD Shipment Report, panel makers are targeting 3% shipment growth in Q4 of 2010 as the capacity utilizations have been in a controlled range due to the slow demand in the end market and supply-chain inventory adjustments.

“The TFT LCD industry experienced an oversupply in Q3 2010 and, as a result, shipments declined, panel prices fell, and suppliers reduced capacity utilization rates due to the lack of orders and inventory reduction. However, even as overall shipments declined, LED-backlit-panel shipments are still growing, continuing the industry’s irreversible trend toward LED,” says David Hsieh, VP Greater China market, DisplaySearch.

Table: Top Three LED Panel Suppliers for Each Application in Q3 2010 Rank

LCD Monitor

Notebook PC

Mini/ Note/Slate

LCDT V

Public Display

1.

LG Display

LG Display

LG Display

LG Display

Sharp

2.

AUO

Samsung

Samsung

Samsung

Samsung

3.

Chimei

AUO

HannStar

NA

Sharp

Source: DisplaySearch Quar terly L arge-Area T F T LCD Shipment Repor t

january/february 2011 | 35

DuPont Produces Tedlar at North Carolina Plant

IMEC and Partners Support Smart Textile Manufacturing

As part of DuPont’s multi-phase $295 million investment in doubling Tedlar film capacity, the company has revealed that production of polyvinyl fluoride (PVF) polymer resin, used in its Tedlar PVF film was launched at its Fayetteville, NC facility. With this second production line, the company plans to pump up the volume of Tedlar film with additional production also beginning in Circleville, OH, in September of 2011.

Leuven, Belgium-based IMEC and its project partners launched the European FP7 (Framework Program) project called PASTA (Integrating Platform for Advanced Smart Textile Applications) aimed at developing large-area smart textiles. Large-area manufacturability is an essential aspect in bridging the gap between lab prototyping and the industrial manufacturing of smart textiles for sports and leisure wear, technical textiles for safety and monitoring applications, and textiles for healthcare and monitoring purposes.

The PASTA project combines research on electronic packaging and interconnection technology with textile research to realize an innovative approach to smart textiles. By introducing new concepts for electronic packaging and module interconnect, a seamless, more comfortable and more robust integration of electronics will be possible. The research will concentrate on developing a concept for bare die integration into a yarn using micromachining, a new interconnect technology based on mechanical crimping, and the development of a stretchable interposer for stress relief.

IMI Holds Security Printing Conference Information Management Institute (IMI) held its seventh annual Security Printing Conference on November 15-17, 2010, at the Hollywood Beach Marriott in Hollywood, FL. Presentations included security printing, international anti-counterfeiting initiatives, global protection strategy, microtag authentication, inkjet printing for security applications, graphene-based inks for security, variable-data security printing, and more. For more information, visit www.imiconf.com.

Conductive Carbon-Nanotube Inks Print in High Volume Norman, OK-based SouthWestNanoTechnologies presented performance data on its latest conductive carbon-nanotube inks at the Printed Electronics and Photovoltaics USA Conference in Santa Clara, CA, in December, 2010. Philip Wallis, Ph.D., SouthWestNano’s quality director, presented a paper on high-volume, low-cost CNT printing on commercial equipment. He also presented samples using the company’s latest ink products.

European Parliament Drops Priority Substance Restrictions Members of the European Parliament (MEPs) have agreed to drop demands for a list of priority substances for new restrictions under the RoHS Directive. The IPC (Association Connecting Electronics Industries) has opposed the creation of such a list, calling for science to be the basis of all future RoHS revisions.

The list of four substances for priority assessment, also identified as substances of very high concern under REACH, was originally proposed by the EU Commission. Last June, the Parliament’s Environment Committee voted to expand the list to include approximately 40 substances, including brominated flame retardants, such as Tetrabromobisphenol-A (TBBA), the most common flame retardant used in printed boards, despite the fact that TBBPA was declared safe for human health. MEPs also dropped their demand for a revised RoHS Directive to contain a ban on nanosilver. MEPs opted for the mention of a future priority review of nanosilver.

36 | Industrial + Specialty Printing www.industrial-printing.net

RFID Usage Successfully Deployed in Many Stores After a decade of experimentation, RFID is now used by several department stores. The Bloomingdale’s store in Manahttan’s SoHo district is now achieving inventory accuracy of 95%, a lift in sales and margins, and improvements in inventory shrink rates, reports Susan Reda in STORES.org. Dillards reported a 17% improvement in inventory accuracy, along with a time savings of 96% when it comes to performing cycle counts.

Furthermore, American Apparel, having tagged all merchandise, now reports 99% inventory accuracy and 14% sales increase.

These are not the only stores that Reda mentioned. J.C. Penny has implemented RFID tagging in more than 30 stores. Wal Mart tagged jeans, underwear, T-shirts and socks in 2010 and plans to increase tagging other products in the future. Banana Republic has extended its RFID pilot operations. As the cost control, inventory control, and other benefits continue to be appreciated, experts predict that more retail operations will use RFID technology, even on lower-cost items, such as socks and underwear.

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industry insider

The Near-Future of Industrial Printing Ray Greenwood

SGIA

The question of where industrial imaging is going is one of the most widely asked within our industry. People ask me; I ask other people; everyone asks someone. I compare notes with everyone I can. The only way to get an inkling of what might be a trend in industrial imaging is to talk to as many people as possible (printers, substrate manufacturers, ink manufacturers, machine manufacturers) and pay close attention to as many applications as possible.

I am primarily a screen printer; however, it would be negligent to not mention that inkjet, flexography, gravure, pad printing, engraving, and photolithography are all part of the industrial-printing industry.

Though primarily concerned with screen and inkjet printing, I am also aware of other printing methods and where they intersect within our industry.

Let’s break the usual question into usable parts: How big is the industrial screen and digital industry? Which print method is the most lucrative moving forward? What products are the hot, upcoming ones involved with printing? From a wide range of sources, the entire industry in which screen and digital printing are prevalent (textile, graphics, and some industrial and printed electronics) is estimated to be between 23,000-28,000 businesses of all types.

The printed-electronics industry alone on this continent is estimated to be between 6,000-8,000 businesses of all types and sizes.

Industrial screen printing and digital imaging are intertwined within the printedelectronics (PE) industry. Industrial printing comprises perhaps as much as 40% of what we know as the printed-electronics industry. The increasingly high-tech segments of both of these groups became more visible over the past five years as OEMs

and in-plant operations shed dedicated plants for cheaper contractors. As industrial imaging and PE move further into the public eye, they will add to the total number of combined screen and digital businesses.

An important part of this growing market segment views industrial printing as perhaps 40-45% of PE. Because of shared processes and substrates, it is nearly impossible to separate these two accurately. As they emerge further, there will be an increase in the total numbers of both combined in the next three years by perhaps 10-15%.

The total number in screen and digital (23,000-28,000) has not really increased much over the past decade because of the high rate of attrition among textile and graphics screen printers. Typically, 15-20% of all startup textile and graphics shops fail within the first 18 months. A high number of start-up industrial and graphics producers began business in the past three to five years as strictly digital shops, but the real trend in the past two years has been diversification of capability, such as screen printers adding digital and digital operations adding screen printing.

Everyone is augmenting service offerings by adding material handling and finishing capabilities. The industrial and printed-electronics segments have always been far ahead in this respect by incorporating a wide range of integrated print platforms (screen, digital, pad printing, flexo, and gravure). Virtually all industrial printing facilities are integrated at some level.

To get a mental grip on industrial printing, it’s essential to first break down the range of what’s being printed into groups that describe volume and importance.

Volume alone can define a trend. It’s an

expression of demand. More precisely, volume reflects which product becomes a commodity with mass usage as compared to items necessary in sub-assembly for a specific product with more limited usage.

Keep in mind that there are hundreds of specific applications within each of these loose headings.

In printed electronics, we have: • Devices for industry and social services, such as medical sensors, traffic sensors and controls, and fluid, chemical, and gas sensors for disposable, one-time usage • Consumer-driven electronic devices, such as displays, touchscreens, telecom/wireless/personal devices, appliances, and LED, LCD, OLED lighting • Technology controls in automotive, military, aeronautics, and micro- and macro-hydraulics • Interactive/active/passive devices, such as RFID, capacitive RFID, and embedded logic • Specialty applications, including solar In 3-D imaging for packaging, we find: • In-mold decoration/in-mold-labeling • Decoration of finished 3-D parts • Industrial marking and coding systems In near-industrial graphics, we have: • Specialty and challenging substrates, such as glass and engineered plastics • Very short-run prototyping of all types • High-speed label application to finished products • Large-scale mass production of adspecialty and consumer novelty items These lists describe the largest centers of activity within the industrial printing industry. They do not, however, advocate a january/february 2011 | 37

single print process or technology. Some of these, though listed separately, are already intertwined. For example, the high-speed food-packaging industry already uses inline industrial marking and coding, mostly by inkjet, right alongside high-speed roll-toroll label printing, which is often flexo, digital, and some screen. This segment already uses vast quantities of in-mold decorating for disposable packaging— yogurt and dairy labels, for example.

A decade ago, the automotive industry showed new direction by having body and dash panels molded first in color, then with graphics. This trend has spread to everything from computer cases and machine and appliance covers to toys and cellular phones.

The most telling indicators of where printed industrial applications are headed come from substrate and ink manufacturers. They are the first to be asked for the consumables used to create new products or improve existing ones. Although there are constant improvements to the finepitch-printing capabilities of screen presses and ever smaller ink droplets with inkjet printers, both approaches support imaging

resolutions that are high enough to produce a vast array of products. New inks, coatings, functional particles, and substrate innovations are truly driving our existing methods to new places.

Changes in rheology, chemistry, and particle size of conductive inks allow thinner, more complex multilayer circuits, membrane switches, and display technologies. New IR-absorbing/blocking inks, new thermochromic inks, nanoparticle inks, hydrochromic/aquachromic inks, and chemically reactive inks are at the heart of the printing advances so important to the production of medical sensors, chemical/gasmonitoring systems, and disposable sensors.

New varieties of functional inks drive the printed-electronics industry. The in-mold labeling/decorating industry for non-packaging-related hard products is increasing rapidly as the range of deep-draw inks and plastic films grows and diversifies. There appears to be no end to the worldwide thirst for consumer electronics and, therefore, custom shaped and colored, non-durable, plastic-molded goods. Precision, short-run prototyping—especially for off-continent mass production—is an

increasing trend. Inkjet printing and digital milling for soft-material prototype work are on the rise.

It’s far too early to say which direction an industrial printer should take next. However, it is clear that increasing substrate diversity, streamlining production methodology, and increasing quality control are the keys to surviving and staying in the game. The really interesting thing is that industrial printers actually seem to be reinstating a streamlined version of an industrial model that is more than a century old.

This is vertical integration light: Increase your capabilities, send out less sub-assembly work, convert your own raw materials, do all of your own design and engineering, and learn to make a new product that uses similar production platforms.

RAY GREENWOOD SGIA

Ray Greenwood is technical services associate, Specialty Graphic Imaging Association (SGIA), Fairfax, VA.

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ADVERTISING INDEX

January/February 2011

Advertiser

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page

AWT World Trade Inc.

27

Kammann Machines Inc.

Douthitt Corporation

3

MacDermid Autotype

1

Dynamesh Inc.

29

Mimaki USA

7

Franmar Chemical Inc.

IBC

Nazdar

OBC

Graphic Parts INternational

27

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27

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Ampco Manufacturers Inc.

location Coquitlam, British Columbia, Canada other info With its core processing functions in screen printing, digital printing, converting, and supply chain management, Ampco Manufacturers specializes in supplying OEM industries with durable decals, membrane switches, graphic overlays, and fabricated rubber and plastic components. Ampco Manufacturers operates from its 63,000 sq-ft facility in the greater Vancouver area. For more information, visit www. ampcomfg.com.

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Screen-printed, backlit graphics are die cut and applied to plastic switch panels.

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Laser cuting is a dieless method that is also used to shape overlays. Here, a sheet of overlay printed on an HP Indigo is being laser cut.

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Multicolored warning decals are going through the drying process after being screen printed and clear coated.

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Health and safety product liners that were screen printed and die cut are assembled with die-cut adhesive parts in a clean-room environment.

Graphic overlays, printed on an HP Indigo, are being assembled with screen-printed conductive circuits and tactile-dome components to form membrane switches.

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Banners are being printed on a large-format inkjet printer for exterior architectural applications.

40 | Industrial + Specialty Printing www.industrial-printing.net