adhesive biopolmer film lamination hb fuller workshop

7/28/2019 Adhesive Biopolmer Film Lamination Hb Fuller Workshop

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2012 H.B. Fuller Company

Adhesives and KeyEssentials for LaminatingBiopolymer Films intoFlexible Packaging

Lowell Lindquist

Wayne Eklund


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2012 H.B. Fuller Company 2012 H.B. Fuller Company

H.B. Fuller Company 125 years of success as a manufacturer of specialty chemical products

Headquartered in St. Paul , Minnesota

Recognized for quality adhesives, sealants, coatings, and paints

Global with direct presence in 36 countries, 3300 employees, andcustomers in more than 100 nations

2010 sales of $1.4 billion

Public company listed on NYSE (FUL)

Component stock of the Standard & Poors Small Cap Index (S&P 600)


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Organization

Asia Pacific

H.B. Fuller Company is organizedgeographically:

Latin America

North America Europe


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Focus Market Areas Packaging

Case and Carton Container Labeling

Flexible Packaging

Packaging Reinforcement

General Assemble

Building and Construction

Personal Hygiene and Nonwovens

Paper Converting

Consumer Product Adhesives

Paper Converting Polymers

Woodworking


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Outline Flexible Packaging Review

Bio-Films that can be Laminated

Flexible Packaging Applications for Bio-Films

Lamination Processes

Dry Bond

Solvent Free

Bio-Film Surface Treatments

Adhesive Chemistry and Interactions with Bio-Films

Solvent Free

Solvent Based Water Based

Examples of Bio-Film Laminations


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Complete adhesive coverageacross entire film

Bonding a combination of films,foils, or paper

Often reverse printed inkbetween layers

Adhesive thickness ~ 1 lb/ream

Flexible Packaging Structure


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Flexible Packaging Film Cross SectionOuter layerPrinting inkAdhesive

Inner layers / Sealant film, barriers,..

Adhesive

Printing InkPrinting Ink


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Flexible Packaging Structure Substrate Surface

Not perfectly regular

Gaps and irregularities in ink

Adhesive

Must overcome surface irregularity

Typical coat weight 1.0 pounds /ream

Range coat weight 0.8-4.0 pounds/ ream

Thickness 1-5m

~2-6% of a lamination volume isadhesive

Scanning Electron Microscopy (SEM)


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Outer Layers

Reverse printed via flexo orgravure

Provide barrier properties

Carry brand image

Typical films

Cellophane PLA Paper Aliphatic-Aromatic Polyesters Blends of bio-esters Polypropylene (OPP) and Metalized

Oriented Polypropylene (MOPP)

Aclar

Polyester (PET) and MetalizedPolyester (METPET)

Nylon

Foil

Inner Layers

Primary purpose is to sealpackage

Direct contact with fill goods

Typical Films

Bio - Polyethylene (PE) PLA PHA Starch Based TPUs Aliphatic-Aromatic Polyesters PGA Blends of bio-esters Polypropylene (CPP or OPP) Polyethylene (LDPE, LLDPE,

metallocene, EVA, etc.)

Typical Package Construction

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Flexible Packaging Market Adhesives Perspective

Solvent Free Water-based Solvent-based

Market Volume

High Performance (Foil)

RetortDifficult Foil

Mid Performance (Film)

Barrier to BarrierChemical Resistance

Heat Resistance

General Purpose (Film)

Dry GoodsConfectionery SnackLid Stock

Cellophane with Barrier

Biodegradable Polyesters (PLA,PHA,etc.)



Potential Applications-Bio-Films Frozen Foods

Fresh Cut Produce

Room Temp Confectionary

Snack

Hot Fill

Condiment

Lid Stock

Overwraps

Pasta Package

Some industrial and consumer

Not currently used above hot filltemperature



Application of AdhesivesComparison of Lamination Processes

Solvent Free

Dry Bond



Flexible Packaging AdhesivesDry Bond Laminating Process

In-line corona treatment

Coat weight controlled by gravure

Coat weights of 0.8 -3.0 pound/ream

Line speed limited by drying process

Liquid carrier must be removed for healthand adhesive quality

Nip temperature and pressure as high as

possible limited by film properties Typical pot life is 8 hours

Smoothing bar is required for WBA

Drying related to temperature, air flow, andinlet humidity

Laminate Slit Pouch Fill



Dry Bond Laminator




Treatment level of films Adsorbed water on films due to hydroscopic nature may affect

adhesion

Speed ramp-up-rate is a critical due to tear propagation, many bio-filmsdo not like mechanical shock

Conventional coat weights (0.8 to 3.0 lbs/ream)

Smoothing bar critical for optimum appearance water-base only

Oven temperature limitations due to yield and shrink of some bio-films-(may limit line speed due to slower drying at low temp)

Bio-Film Considerations During Dry Bond LaminationLaminate Slit Pouch Fill




High nip temperature is desirable limited by film stability High nip pressure is desirable limited by film stability

Rewind tensions less critical due to high green strength

Must be aware of film relaxation (elasticity will cause corrugation andcrushed cores)

Sensitive to roll damage like nicks and bruises

Potential for film solvent sensitivity

Modified coat weight testing


Bio-Film Considerations During Dry Bond Lamination



Flexible Packaging AdhesivesSolvent Free Laminating Process

In-line corona treatment

Two part reactive system (meter-mixaccuracy is critical)

Pot life 30 to 60 minutes

Typical line speed > 1000 fpm

Typical coat weight 1.0 lbs/ream

Heat used to adjust viscosity

Very little green strength

Rewind tension is critical due to lack of green strength




Typical Solvent Free Laminator

Adhesive pumpedinto the machine

Primary filmnipped to thesecondary film

Adhesive applied

to the primary film

Lamination wound

onto a core

Secondary filmintroduced

Primary film introduced



Typical Solvent Free Meter-Mix




Check film dyne level treatment level of films (no solvent to help cleanfilm surface)

Adsorbed water on films due to hydroscopic nature may affectadhesion

Controlled speed ramp-up-rate is critical due to tear propagation, many

bio-films do not like mechanical shock Rewind tensions critical due to low adhesive green strength

Less aggressive nip but air must be excluded


Bio-Film Considerations During Solventfree Lamination




Must be aware of film relaxation (elasticity will cause corrugation,crushed cores, curl, ink smearing, and telescoping)

Sensitive to roll damage like nicks and bruises

Potential isocyanate reaction with film and ink components (glycol)

Conventional coat-weights (0.8-1.5 pounds / ream)

Yield and elasticity of some bio-films can create web handlingchallenges


Bio-Film Considerations During Solvent FreeLamination



Comparison of Lamination ProcessesShift toward Solvent Free AdhesivesDry Bond High Green Tack High Strength Adhesives

- High Energy Demand

- Emissions

- Footprint

- Speed Limited by Oven Size

olvent Free High Speed

No Emissions

Low Energy Demand

Small Footprint

- Need for accurate metering

- Little Green Tack



Bio-Film Surface Modification Surface treatments- (Initial treatment critical followed with in-line treatment)

Corona

Plasma

Chemical / Primers

Coatings

PVdC

Acrylic

PVOH

Urethane

Vapor Deposition

Metallization

Ceramic

Why do we treat the films? Remove contamination

Modify the polarity of film surface

Increase the surface roughness on film

Add or enhance chemical functionality of film surface

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Corona Treatment vs. Adhesion

100

200

300

400

500

600

700

0 0.5 1 1.5 2

BondStrength W-minutes/sq.ft.

Corona Treatment StudyPrinted Cello - Clear high slip LDPE



Corona Treatment: Adds polarity to film increasing adhesion

Removes contaminants

Increases surface roughness

Corona Treatment Adds Polarity to Film



Lamination AdhesivesSolvent Free Composition- Typical Example

No Solvent

Reactive chemistry Two-components

60%40%

Isocyanate Functional Prepolymer

Polyol Curative



Lamination AdhesivesSolvent Free Naming and CompositionCommon Names Chemical Representation

PolyolB-side

CurativeHydroxylIsocyanate

A-SideNCO

AdhesivePrepolymer

OH

OHOH


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The two components are mixed and applied to the film but have notreacted

The ratio of the two components is important for polymer creation Low viscosity to allow application to film

Very little green strength to hold films together

Water is supplied from the environment and films

OHOH

OH


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Partial polymerization after 3-12 hours creates enough adhesivestrength to allow film slitting

Curative and water are reacting to begin formation of ideal polymerstructure

Heat will accelerate polymer formation time and decrease time-to-slit.

OHOH

OHOH

OH


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Significant polymerization in 12-48 hours to provide heat resistance forseal making

Bond strength is very high

Water is used in reaction to increase stiffness of polymer by creating aurea group

OH


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Polymerization complete, food can be safely added

Full adhesive strength is produced

Product resistance is developed

This polymer is significantly different from the starting materials


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SF Lamination AdhesivesBio-Film Interactions Hydroscopic films may provide excessive water which will alter the

polymer that is formed

More polyurea (harder, more heat and chemical resistance)

Excessive water can cause CO2 generation (gassing)

Plasticizers can be difficult for SF adhesives to displace for optimum

adhesive strength Glycols and other reactive film components will likely react into the

adhesive which will alter the polymer that is formed

Because of the low molecular weight starting materials SF adhesivescan smear ink when film tensions are not matched. A film that is over

stretched during laminating will relax in the roll with a potential to smearink.

Covalent bonds to film moiety (specifically reaction with OH or COOHgroups)


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Bio-Film Construction Solvent Free

Goal Lamination of renewable films with maximum adhesion

Use 1 mil OPLA and 1mil LDPE

Unprinted films laminated with 1.0 pounds / ream of SF adhesive

Screened three adhesive systems

OPLA / LDPE and OPLA / OPLA for Snack Food


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1 Day 2 Day 5 Day 7 Day

SF Adhesive A

SF Adhesive B

SF Adhesive C

BOPP/BOPP (Reference Laminations)

All three Solvent Free Adhesives have destruct bond level on BOPP


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0

100

200

300400

500

600

700

800

900

1000

1 day2 day 5 day 7 day

SF Adhesive A

SF Adhesive B

SF Adhesive C

OPLA / OPLA

Not all the Solvent Free Adhesives were successful on these films


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0

100

200

300

400

500

600

700

800

900

1000

1 day2 day 5 day 7 day

SF Adhesive A

SF Adhesive B

SF Adhesive C

OPLA / High Slip LDPE

Not all Solvent Free Adhesives were successful on these films


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Bio-Film Construction Solvent FreeOPLA / LDPE and OPLA / OPLA for Snack Food Goal was reached by careful selection of SF adhesive system

Not all SF adhesives give high bond strength on OPLA / OPLA orOPLA / LDPE.

Recommendation: Involve the adhesive supplier early inbio-film projects

Conclusions


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Bio-Film Construction Solvent FreeExample Set #2 OPLA / Cellophane OPLA-PHA blend / Cellophane

OPLA / Met PLA

OPLA / Met PLA-PHA blend


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0

100

200

300

400

500

600

700

Adhesive 1Adhesive 2Adhesive 3

Bio-Film Constructions Solvent FreeBond Strength


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Bio-Film Construction Solvent FreeSample Set #2-ConclusionsLamination NotesOPLA / Cellophane Adhesive selection is critical, can achieve

excellent bonding.

PHA / Cellophane Adhesive selection is critical, can achieve

excellent bonding.OPLA / Met PLA These films had metal transfer to adhesive,

need to run primer study

OPLA / PHA Adhesive selection is critical, can achieveexcellent bonding.


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Flexible Packaging AdhesivesSolvent Based Composition Typical Example35%

5%

60% Prepolymer

CurativeSolvent

Long pot life

Very low viscosity at application station Very high viscosity at nipping station

Solvent must be removed in application process


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Common Names Chemical RepresentationPolyolB-side

Curative

HydroxylIsocyanate

A-SideNCO

Adhesive

SolventEthyl Acetate

OHOH

OH

Solvent

Lamination AdhesivesSolvent Based Naming and Composition

Sol ent Based Dr Bond Laminating


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The three components are in solution Very low viscosity due to solvent

Water is supplied from the environment or films

Solvent is a carrier to get the adhesive to the film

Application Drying Nipping

Solvent Based Dry Bond Laminating

OHOH

S l t B d D B d L i ti


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An in-line oven is used to evaporate the solvent

The chemical reaction is the same as for a solvent free adhesive but thestarting molecules are much larger

Reaction is not completed



OHOH


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The solvent is evaporated before nipping (dry bond)

Very high viscosity due to loss of solvent = high green strength

Oven air flow and temperature adjusted to evaporate all the solvent

Chemical reaction is not complete

OHOH




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Solvent Based Dry Bond

High starting molecular weight allows for slitting in as quick as one hour.

Curative and water react to form ideal polymer structure Heat will accelerate polymer formation time and decrease time-to-slit.

OH

OH

OH


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Significant polymerization to provide heat resistance for seal making

Less time to get to high polymer formation because of high molecular weightstarting material

Bond strength is very high

Water is used in reaction to increase stiffness of polymer


OH


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Polymerization complete, food can be safely added

Full adhesive strength allows for freezing, boiling, microwaving, etc.Thermal resistance dependant on films and adhesive

Product resistance is developed

Chemical resistance is one of the last properties to develop



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SB Lamination AdhesivesBio-Film Interactions Ethyl acetate in adhesive may soften bio-film resulting in poor web

handling, frosting, shrinking

Hydroscopic films may provide excessive water which will alter thepolymer that is formed

More polyurea (harder, more heat and chemical resistance)

Excessive water can cause CO2 generation (gassing)

Glycols and other reactive film components will likely react into theadhesive which will alter the polymer that is formed

Covalent bonds to film moiety (specifically reaction with OH or COOHgroups)


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40%

58%

2%

WB Polymer

water

Crosslinker - optional

Long pot life Can add cross-linker for added performance

Very low application viscosity

Water has to be removed in application process

Flexible Packaging AdhesivesWater Based Composition Typical Example


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WB Adhesive isgravure applied tothe film.

Water is evaporatedin the oven, film ofadhesive is formed.

Second film is drybonded to adhesive.

Primary Film

Primary Film

Coalesced Adhesive

Primary FilmCoalesced Adhesive

Secondary Film

Water Based Dry Bond


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The polymer cures, flows, crystallizes over a short time period and hasenough bond strength to be slit

Drying conditions should be ramped to avoid skinning or bubbling

Aggressive nip to increase bond strength and improve appearance

Nip conditions specifically set to match Tg of adhesive withoutexceeding film handling limits

Pouching is possible when the polymer is near full cure and has enoughheat resistance to make heat seals.


Primary FilmCoalesced Adhesive

Secondary Film

Water Based Dry Bond


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Bio-Film Construction Dry Bond WB Goal lightly printed biodegradable lid for biodegradable tray with

superior film-to-film adhesion

Use matched 1 mil oriented multilayer films for best web handling

Reverse printed with light ink coverage

Screened six adhesives and two co-reactants Both adhesive and co-reactant impact adhesion values

OPLA / OPLA for Lidstock


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0

100

200

300

400

500

600

700

800

Acrylic /CR1

Acrylic /CR2

Hybrid A /CR1

Hybrid A /CR2

Hybrid B /CR1

Hybrid B /CR2

UrethaneA / CR1

UrethaneA / CR2

UrethaneB / CR1

UrethaneB / CR2

UrethaneC / CR1

UrethaneC / CR2

Green peel

24 hr peel

2 week peel

PLA / PLA Bond StrengthDry Bond - WB


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Bio-Film Construction Dry Bond WBOPLA / OPLA for Lidstock Goal was reached

Acrylic performance is greatly influenced by co-reactant selection

Acrylic performance often approached urethane performancebased on selection

Not all urethanes are better than acrylics, selection of urethaneadhesive is important

Match the chemistry

Recommendation: Involve the adhesive supplier early in

bio-film projects

Conclusions


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Bio-Film Construction Dry Bond WBCellophane / Ecoflex+PLA blend for Compostable Pouches Goal printed biodegradable lid for biodegradable tray with superior

adhesion

Use matched 1 mil oriented multilayer films for best web handling

Reverse printed with light ink coverage

Choice of WB dry bond dictated by existing assets


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Bio-Film Construction Dry Bond WBCellophane / Ecoflex+PLA blend for Compostable Pouches

0

100

200

300

400

500

600grams / inch

Cellophane / LDPE Cellophane / Ecoflex+PLA


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Bio-Film Construction Dry Bond WBCellophane / Ecoflex+PLA blend for Compostable Pouches Goal was reached

The compostable sealant had web handling like a conventional sealant

The compostable sealant had superior adhesion properties to LDPEwith this adhesive.

Recommendation: Involve the adhesive supplier early inbio-film projects

Conclusions


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Adhesive ComparisonSolventBased Solvent Free Water Based

Coat Weight(#/Ream)

1.5-3.5 1.0-1.8 1.0-2.0

Initial Bonds 300 grams 20 grams 300 grams

Viscosity Low High Low

Pot Life 8 hours 30 minutes 8 hours

Retained Solvent Possible No Amine possible

Emissions Yes No No

Energy used High Low High

Lamination speed Oven limit 1500 Oven limit

Time to Slit 2 hours 12 hours 1 hour

Fire Hazard Yes No No

Cost (adhesive +energy)

3.5X X 2.7X


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Last Example

PLA / MetPLA snack food application


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Last Example

Correct adhesive gives high bondstrength

Correct adhesive gives soundreduction

Working together acceleratessuccess


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ITR Workshop SupportHB Fuller would like to thank the following supportersfor their contributions to this workshop!Taghleef Industries

Innovia

Metabolix

BioBag

Heritage Plastics/Plastimin

Imaflex

Sierra Converting


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Thank You

This presentation is for informational purposes only and does not constitute an offer by H.B. Fullerto sell or a warranty of any kind.

adhesive biopolmer film lamination hb fuller workshop

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