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The Changing Market - From Monolayer to Multilayer CoextrusionFlexPackCon 2016Memphis, TN
Dan FallaOctober, 2016
Source: PMMI 2010 Report & NOVA Chemicals View
Flexible Packaging Statistics
2
• Provides engineered films over a wider variety of widths and line speeds with unique properties
• Offers cost savings on the amount of premium resins used by filling the core layer with lower cost materials
• Allows multi-layer, multi-functional structures to be produced in a single pass
UNIQUE PROPERTIES LOWER COST SAVE TIME
Photo Courtesy Reifenhauser
Conversion from Mono-Layer to Co-extrusion
3
Co-Extrusion Benefits
• Combine the desirable characteristics of multiple materials into one structure to achieve enhanced properties.
• Produce multilayer sheet, blown film, cast film, tubing, wire coating and profiles.
• Imparts unique properties to the film structure.
• Reduces need for lamination.• Tailor low seal initiation, stiffness, barrier
and sealant layer.• Use less expensive material in the bulk layer
to create a more functional, economical film.Photo Courtesy Reifenhauser
The goal of food packaging is to contain food in a cost-effective way that satisfies industry requirements and consumer desires, maintain food safety, and minimize environmental impact.
4
Film Extrusion Equipment Trends
5
Photo Courtesy Reifenhauser
Co-ex FundamentalsThe making of an engineered film
6
Horizontal Oscillating Nip
Photo Courtesy Brampton Engineering
Randomizing Haul-off
Bubble Stabilizing Cage
Air Ring
Extruders
Feeding & Control
Bubble Collapsing Frame
Control Panel
Secondary Nip
Typical Multi-Layer Co-extrusion Line
7
Cost is always an important consideration while achieving the desired properties in a given film structure. The ultimate objective is to increase productivity, down-guage, and improve performance.
“The Balancing Act”: for Engineered Films
PERFORMANCECOST
8
Print layer –advertise &
display graphics
Adhesive/Tie – bonds
incompatible materials
Barrier –improved shelf life
Structural –enhanced
film machinability & physicals
Abuse – protect package during handling and transportation
Sealant –maintain package
integrity at faster
packaging speeds
What do high performing films need?
Photo Courtesy: Robert Kneschke/Shutterstock.com
9
Packages can be surface printed or reverse printed using flexographic and/or rotogravure printing. Reverse printing on PET/OPP protects the print from scratching. Surface printing may also have an over-lacquer applied to it to protect the print.
Print layer
Print layer –advertise &
display graphics
Adhesive/Tie– bonds
incompatible materials
Barrier –improved shelf life
Structural –enhanced film machinability & physicals
Abuse –protect
package during
handling and transportation
Sealant –maintain package
integrity at faster
packaging speeds
10
Tie layers comprised of functional polymers extruded between dissimilar materials in coextrusion or coating are intended to keep different layers bonded and prevent delamination.
Tie Layer
*http://www2.dupont.com/Packaging_Resins/en_US/Modeling_Tools/Tie_Resin_Selector/
Chart courtesy of DuPont Packaging and Industrial Polymers
Print layer –advertise &
display graphics
Adhesive/Tie– bonds
incompatible materials
Barrier –improved shelf life
Structural –enhanced film machinability & physicals
Abuse –protect
package during
handling and transportation
Sealant –maintain package
integrity at faster
packaging speeds
PolyesterEVOH
Nylon 6Polystyrene
PolypropyleneHDPELDPE
EVAZinc lonomer
Sodium lonomerAcid Copolymer
Good
Fair
Poor
PolyethyleneTie
Nylon
Maleic anhydride modified polyolefins are commonly used for bonding to Nylon & EVOH for barrier structures
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Flexible packaging films provide barrier to gases such as oxygen, nitrogen, carbon dioxide, and water vapor. It is important to know the packaging environment during filling, processing, distribution, and storage to determine permeation needs. Taste and aroma barrier can be important in some applications. Oil/grease resistance of a polymer is influenced by its polarity and crystallinity.
Barrier Layer
Moisture (WVTR)
Al-FoilmOPPmPET
Barrier HDPEHDPEOPPPVdCLDPEEVA
IonomerPET
EVOHNylon
Oxygen (OTR)
Oxygen(OTR)
Al-FoilEVOHmPETPVdCNylonMOPPPETOPP
Barrier HDPEHDPELDPEEVA
Ionomer
Barrier properties –decreasing performance
Chart data source: NOVA Chemicals
Print layer –advertise &
display graphics
Adhesive/Tie– bonds
incompatible materials
Barrier –improved shelf life
Structural –enhanced film machinability & physicals
Abuse –protect
package during
handling and transportation
Sealant –maintain package
integrity at faster
packaging speeds
12
This layer provides machinability, a balance of stiffness and toughness, and sometimes optics. As density increases, stiffness increases, and toughness and optics decrease. Stiffeners add bulk to the package, allowing it to hold its shape more easily. HDPE blends with butene LLDPE and/or octene LLDPE may offer a good balance of stiffness and toughness.
Structural/Stiffness Layer
The ability of a film to run on
packaging equipment
without difficulty
Photo Courtesy Macro Engineering
Print layer –advertise &
display graphics
Adhesive/Tie– bonds
incompatible materials
Barrier –improved shelf life
Structural –enhanced
film machinability & physicals
Abuse –protect
package during
handling and transportation
Sealant –maintain package
integrity at faster
packaging speeds
13
• Machine direction or cross directional tear strength and puncture are important for packaging sharp objects
• Dart impact is the ability of package to withstand a drop from a store shelf or countertop• Abrasion, flex crack resistance are also important attributes
Abuse Resistance Layer
Print layer –advertise &
display graphics
Adhesive/Tie– bonds
incompatible materials
Barrier –improved shelf life
Structural –enhanced film machinability & physicals
Abuse –protect
package during
handling and transportation
Sealant –maintain package
integrity at faster
packaging speeds
Scuff marks are caused by packages rubbing against each other as well as with secondary packaging during handling and transportation.
14
Sealants maintain package integrity and protect its contents. Choose a sealant that is able to seal over a wide range of temperatures, has good hot tack, heat seal, and is able to seal through contamination.
Sealant Layer
Resins Hot Tack
Temp Range
Low Seal temp
Seal throughcontamination
LDPE X X X X
LLDPE XX XX X XX
ULDPE XX XX XXX XX
mPEPlastomer XXX X XXXX XX
EVA XX XX XXX XX
EEA XXXX XXX XXX XXXX
Ionomer XXXX XXX XXX XXX
X = Poor; XX = Average; XXX = Good; XXXX = Excellent
Print layer –advertise &
display graphics
Adhesive/Tie– bonds
incompatible materials
Barrier –improved shelf life
Structural –enhanced film machinability & physicals
Abuse –protect
package during
handling and transportation
Sealant –maintain package
integrity at faster
packaging speeds
15
Engineered Structure: I-Beam Effect
Stiffer films feel thicker than softer films. Also, downgauging of films can be limited by film stiffness due to packing systems. Separation of HDPE will result in higher film stiffness: I-Beam Effect
http://commons.wikimedia.org/wiki/File:Beam_mode_3.gif
http://commons.wikimedia.org/wiki/File:Beam_mode_2.gifLLDPE
LLDPELLDPELLDPE
HDPE
HDPE
Stiffness
HDPE
HDPE
vLLDPE vLLDPEvLLDPE
HDPE
OTR 67.8 cc/100in2/day 67.6 cc/100in2/day 67.7 cc/100in2/day
WVTR 0.16 g/100in2/day 0.16 g/100in2/day 0.17 g/100in2/day
1% Secant 564 Mpa 568 Mpa 568 Mpa
MD Tear 491 g 506 g 507 g
Bending Stiffness
5.0N-um 5.8N-um 7.7N-um
16
LLDPE
Cost Savings from Downgauging: Poultry Bag
C8 LLDPE
HDPE
C8 LLDPE
vLLDPE
HDPE
C8 LLDPE
vLLDPE
Barrier HDPE
C8 LLDPE
3.25 mil9.06¢/msi
C8 LLDPE
1990
1996
2000
20162010
4.0 mil 3.0 mil 2.75 mil 2.75 mil
8.36¢/msi 7.12¢/msi 6.67¢/msi10.6¢/msi
Cost
vLLDPEB.HDPE
LLDPE
B.HDPE
C8 LLDPE
Desired Properties
Medium oxygen barrier
Seal-through contamination
Dart and puncture resistance
Burn-through resistance
VFFS capability
17
C8 LLDPE
Tie
Tie
C8 LLDPE
EVOH
3.5 mil
15.90¢/msi
3.25 mil
14.08¢/msi
vLLDPE
C8 LLDPE
Tie
EVOH
Tie
C8 LLDPE
vLLDPE
C8 LLDPE
HDPE
TieEVOH
TieBarrier HDPE
C8 LLDPE
vLLDPE
3.25 mil
13.73¢/msi
19952008 2016
Film Application Structures: Barrier Meat
Cost
Desired Properties
Medium/ High oxygen barrier
Abuse resistance
Seal-through contamination
Excellent clarity, high gloss
18
C8 LLDPE
www.dupont.com
Typical Film Structures
19
Blown Film Coextrusion
Film Application Structures
HDPE (Moisture Barrier type)
HDPE (Moisture Barrier type)
Peel Seal PB / EVA/ LDPE blends or Ionomer
HDPE
LLDPE
Cereal Inner Liner
Moisture barrier HDPE such as SURPASS HPs167-AB resin offer a best-in-class solution, with as much as 50% improvement in barrier performance (both moisture and oxygen) and significant improvement in stiffness over conventional high density polyethylene resins.
Desired PropertiesMoisture barrier
Good peel seal properties
VFFS machinability• Hot tack strength• Designed stiffness
Puncture resistanceBarrier HDPE
20
Adhesive Lamination
Film Application Structures
Adhesive
C8LLDPE
C4LLDPE or sLLDPE
C4LLDPE or sLLDPE
C8 LLDPE
vLLDPE
OPPInk
Retail Salad Bag
Lettuces continue to "breathe" even after they've been picked. To keep salads at peak freshness, special breathable bags are designed to allow the right amount of oxygen in and carbon dioxide to escape, preserving their just-picked flavor.
Desired Properties
Oxygen barrier (breathability)
VFFS machinability• Hot tack strength• Seal-through
contamination
Reverse Printed OPPThin seal layer with vLLDPE
21
Adhesive
C8LLDPE
C4LLDPE
C4LLDPE
C8 LLDPE
C8 LLDPE
OPP or PETInk
Film Application Structures
Adhesive Lamination
Frozen Microwavable Vegetable Bag
From freezer to your dinner table in seconds? Yes, the microwavable frozen steam bag offers not only quick and easy meal preparation, but also healthy choices for families.
Desired Properties
Ability to withstand wide range of temperatures
VFFS machinability• Hot tack strength• Seal-through
contamination
Abuse and scruff resistance
Octene LLDPE are ideal sealants for microwave bag
22
Surpass HPs167-AB HDPE has excellent clarity
Separation of HDPE gives I-Beam effect
Film Application Structures
C4LLDPE
C4LLDPE
PB / EVA/ sLLDPE blends or Ionomer
PP
sLLDPE
Blown Film Coextrusion
Single Slice Cheese Innerwrap
Desired Properties
Machinability
Peelable, hermetic seal
Contact clarity
Easy cheese release
23
Film Application Structures
Blown Film Coextrusion
C4LLDPE or HDPE
C8 LLDPE
Tie
EVOH
Barrier HDPE
C8 LLDPE
vLLDPE or Peel Seal blend
vLLDPE
Tie
Block Cheese Packaging
Desired Properties
Moisture barrier - minimal
Machinability
Peelable, hermetic seal
Contact clarity
Cheese release
vLLDPEs impart excellent physical properties and processibiltiy
24
Film Application Structures
vLLDPE
Barrier HDPETie
Nylon
Tie
HDPEPeel Seal (PB / EVA/ vLLDPE blends or Ionomer)
Nylon
EVOH
Blown Film Coextrusion
Forming Film for Processed Meat
EVOH barrier properties decrease with moisture. Barrier HDPE is used to the EVOH from moisture by placing it on the wet side. Nylon strength increases with moisture.
Desired Properties
Medium oxygen barrier
Abuse resistance
Seal-through contamination
Excellent clarity, high gloss
Thermoformability
Peelable sealBarrier HDPE for EVOH layer
Barrier HDPE
25
HDPE
LLDPE/LDPE
LDPE
LDPE
Film Application Structures
Collation Shrink Film
Products packaged using collated shrink films have eliminated cardboard trays and evolved to nested or staggered configurations resulting in increased product quantity for a given footprint resulting in HUGE savings.
Desired Properties
Reproducible shrink properties
Low-tunnel-temp shrink initiation
Stiffness for high converting speeds
Excellent tear, puncture, and tensile yield characteristics
Blown Film Coextrusion
LDPE skins for shrinkage Core for strength
26
EVA/PBPE
NylonPE
Sealant layer
Barrier
Sealant layer
Barrier and improvedthermoformability
PE contains tie concentrate to
ensure bonding with Nylon
4-mil Peelable Lid
7-mil Bottom Base
Balanced HDPE to help reduce curl
Film Application Structures
Nylon
Peel Seal
Nylon
Tie
Nylon
Tie
sLLDPE
HDPE + Tie
Barrier HDPE + Tie
Nylon
Tie
Nylon
Tie
sLLDPE
HDPE + Tie
Nylon
Barrier HDPE + Tie
C8 LLDPE
Self Rising Frozen Pizza Package
Key AttributesExcellent thermoforming and resistance to flex cracking
Clarity and peelablity for opening
Maintenance of package integrity
27
• Co-extrusion continues to drive conversion from rigid to flexible packaging
• Key drivers include excellent shelf presence, convenience, and improved manufacturing efficiencies
• Balancing performance and cost becomes a critical factor in co-extruded performance films
• Cost-performance relationships is a critical factor to consider for co-extruded performance films
• Contents of the package drives the demand for different film structures
• Technology will continue to drive multilayer co-extrusion lines to provide even more precise properties in the most cost-effective configurations possible
• It is critical to understand market requirements when designing a film structures to determine best fit.
• Asking the right questions will help improve understanding of what the customer/market really wants/needs
Conclusion
28
Questions?
29
is a registered trademark of NOVA Brands Ltd.; authorized use/utilisation autorisée. Advanced SCLAIRTECH™ is a trademark of NOVA Chemicals. SCLAIR® is a registeredtrademark of NOVA Chemicals Corporation in Canada and of NOVA Chemicals (International) S.A. elsewhere; authorized use/utilisation autorisée. NOVAPOL® is a registered trademark of NOVA Brands Ltd.; authorized use/utilisation autorisée. SURPASS® is a registered trademark of NOVA Chemicals Corporation in Canada and of NOVA Chemicals (International) S.A. elsewhere.
The information contained herein is provided for general reference purposes only.By providing the information contained herein, NOVA Chemicals makes no guaranty or warranty and does not assume any liability, with respect to the accuracy or completeness of such information, or product results in any specific instance, and hereby expressly disclaims any implied warranties of merchantability or fitness for a particular purpose or any other warranties or representations whatsoever, expressed or implied. Nothing contained herein shall be construed as a license to use the products of NOVA Chemicals in any manner that would infringe any patent. Nothing herein shall be copied, reproduced, distributed or otherwise used without the express written permission of NOVA Chemicals.
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