New developments and latest trends in cast stretch film extrusion Giovanni Roscini CSO of Torninova Srl AMI Stretch & Shrink 2011, Atlanta (USA)
Future trends for stretch film market
• Sustainable packaging will create more pull for downgauging, driving technical innovations on machines • Low Gauge (9-12 øm cast hand film rolls, <15 øm machine film rolls): Thinner but stronger film Saving up to 40% per pallet High quality performance Eco-Friendly • Low Cost -> Converting Cost -> balance output, gauge, good physical properties & material cost • High Output machine (energy saving, speed over the actual 600 m/min)
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Key Drivers â&#x20AC;˘Resins producers - New resins to increase film processing and higher alpha olefin (HAO) performance benefit - Work closely with film converters to provide technical solutions for end users â&#x20AC;˘Machine producers - Decrease recepies cost - Increase speed and production output - Decrease downtime and increase automation (less manpower) - Energy saving - Production of low gauge film but still ensuring pallet integrity and possibility to use low thickness cores (even coreless) - Layers distribution to increase film performance - Decrease required machine overall dimensions (more compact machines) â&#x20AC;˘Stretch film producers and distributors - Invest in marketing for new films promotion (Think thin to win!) - Place products as an added value - Marketing plan and strategy on cost saving and sustainability for end users Torninova Srl
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Compact Motor Gear a complete new drive concept Power drives used commonly in extrusion systems Hydraulic drives â&#x2021;&#x2019; Hydromotors Water cooled AC (or DC) motors with gear boxes Fully electric drives â&#x2021;&#x2019; High-Torque Motors Comparison of power drives utilized:
Hydromotor Efficiency
Motor and Gearbox
High-Torque Motor
Compact Motor Gear
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Power density
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Environment pollution
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Compact Motor Gear a complete new drive concept Arrangement of four Asynchronous motors in a compact built way; 4 short building 3 phase AC motors built around a central hole Electrical behavior similar to a single asynchronous motor Stators especially designed for frequency controllers Incremental encoder for speed control Safety devices like PTC und KTY- Sensors. Liquid cooling without additional cooling lines Extremely silent due to low circumferential speeds (reduction up to 10 dB(A) compared with standard systems)
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Compact Motor Gear a complete new drive concept Size comparison (for same power output): Compact Motor Gear Oil contents: 14 Ltr. ( 3.7 gallons)
Standard drive Oil contents: 50 Ltr. (13.2 gallons)
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Compact Motor Gear a complete new drive concept Efficient water cooling: direct heat transfer from stator to cooling coil and motor housing
Easy replacement of single motor; in case of emergency replacement, possibility to continue working without one or two motors
Cooling Supply: 1x Input, 1x Output Connection In common for all four motors Torninova Srl
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Infra Red (IR) heaters
Torninova uses IR heaters on their extruders from more than 7 years to deliver significant energy savings to customers.
Advantages: • significant energy savings ( -30/40% compared to conventional heaters) • quick reach of the set temperature • absolute uniformity of irradiation • possibility of high power in small areas • long life, rapid replacement, ease of assembly Torninova Srl
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Chill-Rolls unit A correct surface finishing has a key role in improving film quality â&#x20AC;˘If the chill-roll surface is too rough, it can scuff the film or cause it to stick to the roll. â&#x20AC;˘With thin films, a too smooth surface finishing can also create a vacuum due to lack of air release, causing the film to stick. Design the best covering surface in order to: - Increase film contact surface and therefore a better cooling outcome - Increase film stability
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Chill-Rolls unit New axial motor directly connected to the chill-rolls Advantages: - No gear box required - No belts required Zero Maintenance Request! - Water cooled motors - Low noise level - Absolute constant and perfect rotation - High motor efficiency
One inner axial motors for each chill-roll with independent controls
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Chill-Rolls unit Integrated thickness measuring device - Thickness measurement of the film immediately after the second chill-roll - Less machine overall dimensions - Total absence of vibrations, wrinkles and longitudinal oscillations - Neck-in thickness measurement - Transversal thickness automatic control - Longitudinal thickness automatic control - Neck-in and dual chamber vacuum boxes automatic control algorithm
Final verification by weight and length measurement (on winder end) of each single produced roll
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FeedBlock and Cast Die New Trends
MULTILAYERS TECHNOLOGY
Number of extruders = number of layers obtained - 3 layers with 3 extruders - 5 layers with 5 extruders - 7 layers with 7 extruders A B C D E
Possibility to use different raw materials for each layers. To improve strength and performance is important to exploit each single layer (especially on downgauging). Possibility to adapt the machine with extruders with specifically dedicated screws for each single layer to be extruded according to the raw material in use. Torninova Srl
Example
Importance of sub skins
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Winder HISTORICAL FACT: First winder in the world on a stretch film machine that was able to produce inline hand rolls (1997) on 2-inch core
NEW DEVELOPMENTS: • Remove the overall pneumatics from the winder • Improve the exterior aspect of the produced rolls for a perfect outcome • Possibility to utilize thin cardboard cores • Decrease of film length from the trims cutting and the web separation to the core winding (< 2 m); low winding pull, rewinding without film stress • Extremely fast cycle time (< 10 sec) • Improve film conduction from extrusion to core winding to improve stability
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Winder Production speed approach to 1.000 m/min New transmissions without contacts: - no belts, no elastic joints and therefore no maintenance Electric winding pressure; - No compressed air or hydraulic systems. Electrically operated systems (with brushless motors) for all the winder operations; - Cores load, rolls unload, turrets rotation, shafts rotation, etc..
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Winder
New contact roll and satellite roll multilayer surface; Magnetic dust helix on first layer creating a spiral from the center towards the edges expelling air
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Winder
Treated surface to improve film gripping on rollers, better stability and cutting resistant surface (scratch-resistant)
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Winder
Hand roll quality; Total absence of air within the rolls (no fish bones) and perfectly smoothed tails (CD-ROM effect) Torninova Srl
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Winder
Rolls quality; Thanks to the satellite roller, the film is winded peripherally until the cut. Winding rolls remain in contact with the contact roller or the satellite roller at all times during index. Torninova Srl
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Winder
What happens when stretch or shrink film is winded around the core?
RADIAL PRESSURE - Film Gauge - Number of film wrapped - Environment - Age of Roll - Film type, formulation, etc.
Factors that influence the applied radial pressureâ &#x201E;â &#x201E;
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Winder
Key Trends on cores – Reduced Wall Segment
Wall (Past)
Wall (Today)
Wall (Tomorrow)
Machine Grade Stretch
12-13 mm
7-8 mm
3-4 mm Coreless ?
Hand-Held Stretch
5-6 mm
4 mm
2-3 mm Coreless ?
How has this been possible? • Improved Film Production • Improved Winding Equipment • Improved Knowledge of Radial Pressures and On-site Measurement • Improved Core Design to Resist Radial Pressure • Engineered Core Materials and Structures
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Winder
Core Technology - 3-inch core, 3 mm wall, weight lower than 350 gr per core - 2-inch core, 2 mm wall, weight lower than 160 gr per core
Modular winding shaft, no core restriction due to low tension of winding, possibility to use standard and thin cores
- Coreless
Dedicated shafts that give the possibility to produce coreless rolls Torninova Srl
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Winder WE ARE ALREADY HERE!! Roll: Gross weight: 2.983 g (6,58 lb) Net weight: 2.844 g (6,27 lb) External diameter: 103,9 mm (4,09 in) Core: Core weight: 139 g (0,31 lb) Core wall: 1,75mm (0,07 in) External diameter: 53,6 mm (2,11 in) Internal diameter: 50.1 mm (1,97 in)
TOTAL ABSENCE OF AIR!!!! Roll made on a COMPACT STRETCH 2.000 MACHINE, 5 LAYERS, HAND AND MACHINE ROLLS QUICKSILVER-4S WINDER
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Winder Fiber vs Plastic Core
Advantages
Disadvantages
Fiber
Plastic
- Lower costs - Ready to be Recycled - More sustainable (from recycled and renewable resource)
- Water resistant - More Dimensionally Stable
- Less water resistant - Less Dimensionally Stable (avoidable with low tension winders with new technologies)
- Higher costs to produce a good and usable product - Brittle at low temps - More Difficult to Recycle - Less sustainable - On hand rolls, creation sharp edges
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Winder
NEW WINDER MODELS QUICKSILVER-4S速 winder: - 4 shafts turret system - For hand and machine rolls on 2 or 3 inches cores - Available sizes from 1.000 mm to 3.000 mm - Very fast cycling time: <10 sec - Working speed of over 800 m/min QUICKGOLD-4S速 winder: - 4 shafts turret system - For hand, machine and jumbo rolls on 2 or 3 inches cores - Jumbo rolls production up to 420 mm of diameter (50 kg rolls) - Available sizes from 1.000 mm to 3.000 mm - Very fast cycling time: <18 sec - Working speed of over 800 m/min - Patented by Torninova Srl Torninova Srl
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Winder
QUICKSILVER-4S® 1000 mm
QUICKGOLD-4S® 1500 mm
For 2.000 mm Winder: Double turret – Two 1.000 mm turrets For 3.000 mm Winder: Double turret – Two 1.500 mm turrets
Maintains high speed, quality and stability of production
NO centre-supported shaft: avoids loss of flexibility on roll width, mechanical problems and increased cycling time NO overhead separated winders: avoids different length and tension of the two webs, avoids necessity of double unloading positions of the produced rolls and double positions for core loading
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Winder - Double turrets system - 4 shafts for each turret - Mechanical speed of 1.000 m/min - Stretch film thickness range from 6 to 50 microns - Contact roll and satellite roll Pressure with electric linear actuators for a controlled thrust - Torninova winding algorithm (VP2); rolls diameter control, film thickness, air quantity, roll eccentricity, roll edge, etc.. - Minimum cycle time: <10 sec - Automatic load of cardboard cores with single cores storage area on ground level - Automatic download of produced rolls conveyed to a single collecting area - Automatic weighting of each roll
QUICKSILVER-4S速 2.000 WINDER
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Trims in-line recycling AIM: the system must operate as if the trims do not exist!! The user is satisfied when the trims no longer represent a production variable
Solution with rere-pelletizing inin-line systems It is a good solution but not the best If the recycled pellets are immediately reutilized:
Extra extruder handling during production
3째fusion of material
Increase of production costs
If the recycled pellets are stored to be utilized later:
Difficult and complicated recepies handling
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Increase of required production spaces
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Trims in-line recycling ALTERNATIVE SOLUTION IN-LINE RECLAIM OF ALL TRIMS WITH SAME RECEPIE THIS SOLUTION MUST BE RELIABLE AND GUARANTEED FOR EACH SPEED, THICKNESS AND RECEPIE UTILIZED NO GELS Because virgin and reclaimed materials are blended avoiding creation of space for oxygen
NO PROBLEMS The operator can remain on the „first floor‰
NO MATERIAL 3° EXTRUSION
NO EXTRUDER PRESSURE OSCILLATIONS No longitudinal oscillations as in side trims extrusion system
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Trims in-line recycling
DETAIL OF THE IN-LINE RECLAIM SYSTEM „FULLFEED®‰ DESIGNED BY TORNINOVA SRL
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Trims in-line recycling EACH EXTRUDERÊS PRESSURE REMAINS CONSTANT DURING ALL THE PRODUCTION PROCESS, INCLUDING THE EXTRUDER WHERE THE FLUFF IS RE-INSERTED. THIS IS DUE TO THE BLENDING WITH „NO AIR‰ AND TO TORNINOVA (VP1) ALGORITHM THAT AUTOMATICALLY CONTROLS ANY TRIMMING VARIATION WITHOUT OPERATOR INTERVENTION EXTRUDER ± 100 mm PRESSURE PROGRESS (RED LINE) WHERE ALL THE SYSTEM TRIMS ARE RECLAIMED (UP TO 50% OF THE SYSTEM GROSS PRODUCTION CAPACITY)
PRESSURE CONTROL WINDOW FOR 1.000 mm MACHINE EQUIPPED WITH EXTRUDERS OF 55, 70 AND 100 mm DIAMETER MOST EXTREME CASE Torninova Srl
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Overall Dimensions Reduction LAYOUT MACHINE COMPACT STRETCH 2.000 by TORNINOVA SRL
Edge Trims Granulator
10 m
Cores Storage
Produced Rolls collection table
EQUIPPED WITH: 5 LAYERS – 4 EXTRUDERS QUICKSILVER-4S® WINDER DOSING UNITS FULLFEED® SYSTEM WATER THERMOREGULATION PUMPS SYSTEM
ONLY 100 m2 REQUIRED!!
H=7m
MAIN CABINET
10 m Torninova Srl
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Which is the ideal plant for a stretch film producer? •EASE OF OPERATIONS •REDUCED OVERALL DIMENSIONS •REDUCED PRODUCTION WASTES (<0,5%) DURING START UP AND THICKNESS CHANGES
•TOTAL ABSENCE OF PROBLEMS (CORES HANDLING, TRIMMING, ROLLS COLLECTION)
•VERY FAST AUTOMATIC THICKNESS CHANGES (MACHINE ACCELERATIONS AND DECELERATIONS WITHOUT MACHINE HALTS AND PRODUCT DAMAGE)
•REDUCED ENERGY CONSUMPTION (< 0,45 kW/Kg) •REDUCED NOISE AND ABSENCE OF DUST Torninova Srl
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Which are the variables that a plant producer must keep into consideration?
•PRODUCE SYSTEMS ACCORDING TO HIS PRODUCT PRODUCTION DIRECT EXPERIENCE. •TECHNOLOGY; ALWAYS BE ON THE CUTTING-EDGE OF THE MARKET AND OF ITS MUTABLE DEMANDS AND ALWAYS TAKING INTO CONSIDERATION THE SUSTAINABILITY, INCREASING SPEED OF PRODUCTION AND DECREASING ENERGY CONSUMPTION.
•SPECIFICITY; NO „PRE-ASSEMBELED‰ PLANTS; THE PLANT SHOULD NOT BE A SUM OF DIFFERENT COMPONENTS NOT SPECIFICALLY DESIGNED FOR STRETCH FILM PRODUCTION AND WITH SEPARATED CONTROLS. EACH PART OF THE PLANT SHOULD BE SPECIFICALLY DEVELOPED TO BE AN INTEGRAL AND INSEPARABLE COMPONENT OF AN EFFICIENT SYSTEM.
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Thank You! We would like to thank the following companies for their contribution and support to this presentation:
For further information: giovanni.roscini@torninova.com Torninova Srl
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