Mini Flute Packaging

T E C H N I C A L

B U L L E T I N

Mini-Flute Packaging

B,E,F and N Flute

Outer Beauty/Inner Strength Mini-Flute is not short for a small flutist in an orchestra; it refers to the family of corrugate that uses small flutes (low profile), and a high number of flutes per inch (flute pitch) to produce a smooth surface. When a printed top-sheet is applied to single face, the result is a corrugated box with the look and feel of a folding carton. Typical miniflute (micro-flute) profiles include B, E, F and N flutes.

Why mini-flute?

In the modern retail environment, the carton is the silent salesman attracting attention to your product. The addition of high-end graphics has converted the conventional brown-box into the primary product package. The traditional secondary or tertiary role of corrugated is now that of a messenger of quality inside. Mini-flute minimizes the washboard look of wider flute profiles and gives the appearance of a paperboardfolding carton.

Did You Know?

History of corrugated in the America • 1690: The first paper mill in North America built near Philadelphia.

• 1767: England imposed the Stamp Act, which included a tax on all paper made in the colonies. Many consider this fuel for the American Revolution.

• 1856: Corrugated was patented for sweatband material in hats.

• 1871: Unlined corrugated first appears as packaging material for glass. Albert L. Jones patents “A” flute to wrap glass chimneys for kerosene lamps.

• 1895: “Cellular board boxes”, later called corrugated boxes, are produced by sandwiching fluted medium between two liners. Wells Fargo begins using boxes for small freight shipments.

• 1919: Railroad classification codified into Rule 41, which specifies minimum caliper and Mullen (burst strength).

• 1968: National Motor Freight Classification (NMFC) Item 222 provides truck-shipping rules and specifications for corrugated packaging.

• 1991: The Edge Crush Test is added to NMFC and Rule 41 as an alternative to burst strength.

• 1990’s to 2005: Mini-flute takes off, as

customers demand high-quality printing and finishing on corrugated cartons. Club stores and large retailers require the “box to sell the product” and become the silent salesman of the retail aisle.

Have you seen this on a corrugated box and wondered what it meant?

Deconstructing mini-flute: The structure of mini-flute is the same as conventional corrugated, except the flute height is lower and the external liner (top sheet) is printed. Additionally, the top sheet is usually printed on a 10 or 12 pt. stock, which provides a smooth external surface and excellent printability. This also dramatically reduces or eliminates any score fracturing that can occur when you laminate a label onto a corrugated sheet. There are top sheet alternatives including foil laminated paperboard, CCNB and variety other substrates.

These circles are called Certificates of Box Manufacture or “Box Certs”.

A throwback to federal regulation of the trucking industry, the government

specified minimum packaging required for freight to be accepted for truck and/or rail transport. The regulations dictate that all shipping cartons bear a manufacturer’s certification of compliance to transport regulation and a guarantee that you are getting what you paid for.

Each number is a specification threshold for the box’s performance standards.

On most top sheets, DISC can apply unique coatings, stamp or emboss to enhance the graphic features and wow the consumer. You can also add cellophane or rigid window materials to allow easy product viewing without comprising product protection. Pre-printed top sheet liners can be printed using offset sheet fed or flexo web presses. In most instances, offset is more cost effective because of the lower plate costs, which also provides flexibility for copy and image changes.

Flexo is typically meant for large volume runs due to the high up-front plate and die costs.

A. Bursting Strength (Mullen Test) simply measures the strength of the liners (the two outside walls of the corrugate). The test is a measure of the pressure required to burst through or rupture a piece of board. For example, 200 pounds of pressure is required to rupture a piece of 200-pound test corrugated.

B. The Minimum Combination Weight is the total weight of the liners. Example: a 200 lb. test carton has two 42 lb. liners so the total is 84.

C. Size limit is a recommendation of the maximum outside dimension (MOD) to hold a certain weight.

Formula: Length + Width + Depth = MOD D. Gross Weight Limit is the maximum weight that a carton and its contents should weight in pounds.

Next we’ll look at the middle or medium, which is the fluted portion of the corrugated. The inspiration behind creating flutes came from the architectural structures of arches and columns. When sandwiched between two liners the arches are capable of supporting a significant amount of weight and when placed on end the column effect provides excellent stacking strength. The term flute is named after the vertical grooves in an architectural column.

Kraft (brown paper stock) is traditionally used to create the medium in weights from 18 to 40 lbs. The flute configuration is formed by applying steam for moisture to the sheet as it comes off the role. The paper is pressed through two gear-like rollers called corrugating rolls.

The next step is applying the liner (inside ply) to the flutes. An adhesive, in the form of starch, is applied to the tips of the fluted medium and the linerboard is married to the flute forming “single face” corrugated. Upon exiting a dryer, the exposed edge of the flutes receives an application of a cold glue adhesive and the face liner or top sheet is applied. In many applications, the top sheet is pre-printed with high-quality graphics. The pre-print can be done on a web and applied directly from a roll or sheet-fed, which is Disc Graphics’ specialty. The finished role is slit into sheets and stacked in preparation for die cutting, folding, gluing and conversion into a folding carton or other constructions.

Above is the other common Box Certificate, which includes Edge Crush Test (ECT).

This alternative classification focuses on the edgewise compression or stacking strength of the carton rather than burst resistance. Simply stated ECT measures the amount of force, in terms of pounds, necessary to crush the edge of a corrugated box.

Resources: Perkins, S. and Schnell, P. (2000). The Corrugated Containers Manufacturing Process. Tappi Press: Danvers, MA. Fibre Box Association (1999). Fibre Box Handbook. Fibre Box Association: Rolling Meadows, Il.

Flute Height Specification: Below are the most common mini-flute configurations:

47 Flutes Per Ft. / 155 Per Meter

B

.097

N-flute is one of the smallest flute configurations, which minimizes the look of corrugated without comprising the strength you expect.

Which liner/medium configurations to use?

The look and cost of the final carton will be impacted by your choice of liner and medium: • Typical configuration for a printed mini- flute carton is a kraft inside liner and medium, combined with a printed top sheet.

• White liner/kraft medium. The white liner is normally a #3 grade referred to as “mottled white”, “Oyster white” or “Sno-Top”. This configuration is used in beverage boxes, pizza and food boxes.

This offers modest printability, but presents a more upscale look than Kraft.

• Triple white: bleached white liner and medium. Used in cosmetics, pharmaceuticals and presents a premium look.

Retail Ready, Shelf Ready, Display Ready and PDQs (Pretty Darn Quick) packaging The term Retail Ready packaging (RRP) generally describes packaging that fits within the meaning of the “five easies”: • Easy to Open • Easy to Identify • Easy to Stock • Easy to Shop • Easy to Dispose

Isopure

Droll Yankees

Isopure 6pk Promo Box w/ Insert Specifications: E-Flute Carton Top Sheet: 12pt. SBS, 4-Color Process + PMS Kraft Medium and Liner

Droll Yankee Bird Feeder Specifications: B-Flute Carton Top Sheet: 12pt. SBS, 4-Color Process Kraft Medium and Liner

K’NEX

K’nex-Motorized Madness Specifications: E-Flute Carton Top Sheet: 10pt. silver-Mylar foil, Hexachrome 6-Color Process + PMS

Hypertherm

Plasma Torch Box Specifications: B-Flute Carton Top Sheet: 12pt. SBS, 4-Color Process Kraft Medium and Liner

10 Gilpin Avenue Hauppauge NY 11788 631.234.1400 discgraphics.com

DISC Products and Services

• Printed paperboard packaging (print, die cut, fold/glue, foil stamping, embossing, UV

coating in-house)

• Print technologies include offset sheet-fed lithography, narrow web flexography, digital

and silk screen

• Printed substrates include all varieties of paperboard comprising SBS, CCNB, SUS;

specialty stocks such as foil laminated board; paper; plastic and synthetic materials

• Mini-flute corrugated for “high-end” graphics (B, E, F and N flute) in house • Rigid boxes and similar specialty packaging • DVD, CD paper inserts, wraps, booklets • Stickers and labels • Commercial printers and posters • Vacuum formed packaging • Displays • Lenticular printing • Windowing (both rigid window and cellophane) • Specialty packages for a variety of products and markets • P.A.S.S. program (Packaging Authentication Security Solutions) • Full service in-house creative team for structural and graphic design