Taşkın ŞEN

Flexible Lamination

2019

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Basic concepts and technologies of lamination for flexible packaging.

Requirements for Flexible Packaging

Solvent-less Lamination process during and after

Solvent-based Lamination process during and after

Our Brand – Flexbond

Curing

Summary

Basic Concepts Main lamination techniques on flexible packagings..

Solventbased coating side view

LCI Results, Energy UseMJ/Ream

Feedstock Processing& Transport

Total

Solvent-free Adhesive 16 37 53

Waterborne Adhesive 31 122 153

Solvent-borne Adhesive 55 203 258

0

100

200

300

Solvent-free Waterborne Solventbased

LCI Results Energy, MJ/Ream

Feedstock Energy Transportation Energy Production and Use

1 ream≈30.000m2

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Basic Concepts

Adhesive Types/Class As supplied (basedon solids)(gr/m2)

As appliedsolids(without-diluent )(gr/m2)

Solventless General and Medium Performance 1,7 1,7

Solventless High/Special Performance 2,8 2,8

Solventbased General and Medium Performance 2,5 4,5

Solventbased High/Special Performance 3,2 6,0

Waterbase General and Medium Performance 1,3 2,6

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Structural features

Physical strength, elongation, abrasion and puncture resistance.

Performance

saleability, environmental tolerance, machine acceptance.

Barrier

Against moisture, gas, odours and ultraviolet light.

Aesthetic

Clarity, opacity, feel and metallic appearance.

Basic Concepts: Properties of Films

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Basic Concepts: Layer Composition

Four layers laminates

Three layers laminates

Two layers laminates

Single layer laminates

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Solvent-less

Solvent-based

Water-based

UV

Wax/Hotmelt

Laquering/Water-based

Surface finishing coating

Seal coating (cold seal)

Barrier coating(special film/alu/paper borne productions, PVDC coating.

Basic Concepts: Lamination Techniques

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RequirementsTypical design of flexible packaging for coffee

PET -> printable abrasion resistentFoil -> gas / aroma barrierPE -> sealable

Flexible films/foils are laminated and used for food packaging gas-proof

flavor proofed, hermetically sealed

water proofed

impermeable for fat

capable for heat sealing/heat sealable

abrasion-resistant

printable

Can only be fulfilled with a combination of films/foils based on different materials

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Advantages• Applicable to porous surfaces

• High operation speed

• Medium Price Level

• Solvent-free operation

• Low cost of operation(without solvent recyling and low work safety conditions)

• Lower investment costs(more complicated machinery)

Disadvantages• Lower initial tack

• Lower temperature / hydrolisis resistance

• High viscosity → Low adhevie coating weight → low adhesion strength

Solventless adhesives-Advantages and Disadvantages

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Solventless adhesives-Advantages and Disadvantages

Adhesive coating station

The amount of glue on the surface is adjusted by the space between therollers and the number of turns.

carrier substrate

lamination station forsolventless adhesives

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Solvent-based adhesives-Advantages and Disadvantages

Advantages

• Compared to solvent free adhesives

• Higher application weights possible (> 3 g/m²)

• Higher molar mass of adhesive structure possible

• Higher amount of polyesters based on aromatic structures possible

• This leads to properties not available by other lamination processes

• High bond strength

• High initial tack

• Good bearing capacity

• High temperature resistance

• Highly hydrolysis resistant

Disadvantages

• Porous materials(e.g. paper) not processable

• Lower processing speed(higher price)

• Higher processing costs(solvent recovery/combustion, labour protection)

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Lamination with solvent based adhesives

Solvent based adhesives – Lamination process

Solvent based adhesive is coated on carrier substrate Solvent is dried from the surface of the carrier substrate Coated carrier is pressed together with 2nd substrate

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Solvent based adhesives – Lamination proces

Coating station forsolvent-based

adhesive

transfer roll

V < 400 m/dak

Carrier substrate

backing roll

Adhesivediluted in

solvent (EA)

film thickness adjusted by gap between rolls and by roll speed difference

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Solventless adhesives –Application Range

Standart

Medium-High Perf.

High Perf.

Highest filling good resistance on Al foil, Boiling and

sterilization resistance on Al foil up to 121°C / 30 min.!

Pharmaceutical industry.

Film/film up to sterilization (85°C 15min.) and pasteurization,

Highest safetyness, greater film range (also PEwhite+EVA)

Very short migration times

Base-system, long potlife, No Pasteurization,

No Boiling, No sterilisation, suitable for all films

except PEwhite+EVA

Medium Perf.

filling good resistance on Alu, boiling on Al foil

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RTC Chemical-FLEXBOND Adhesive

RTC Chemical «Flexbond» adhesivesare based on polyurethanechemistry. They are suitable toproduce food flexible packaging andtechnical laminates.

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Our Brand:FLEXBOND

Substrate surface/Adhesion zone

Cohesion zone

Substrate

Substrate

Adhesive

FROZEN FOODStructures:OPP+white PEPET+PEmetPETmet+PEOPP+PETmet+PE

SAUCESStructures:PET+Alu+PEPET+Alu+OPA+PEPET+PE baririerPE+PET+PE barrier

COFFEEStructures:PET+Alu+PEPET+PETmet+PEOPPmat+Alu+PEPaper+Alu+PE

SnacksStructures:OPP+OPPOPP+PEOPP+PETmet+PE

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RTC Chemical-FLEXBONDPERFORMANCE LEVEL APPLICATIONS

High Performance

Used for packaging structures that need sterilization, for hot filling, for all the

applications that require high thermal and chemical resistance.

fresh pasta, fruit juices, meat and fish, cosmetics, pharmaceuticals

Medium-High Performance

Used for packaging structures that require only pasteurization and a good level

of chemical resistance.

coffee, liquid soaps, spices, sauces, frozen food, milk and derivatives, bakery

products

Medium PerformanceUsed for packaging structures that require high strength and medium heat

resistance and not medium chemical resistance.

Snack food, coffee, rice

General purposeUsed for packaging structures that don’t require any specific performance level.

snack food, chips, dry pasta, cookies, rice

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FLEXBOND-Solventless One Comp.

ONE COMPONENT NCO OH CHARACTERISTICS

RTFB 200 X One component polyester based adhesive, suitable for paper , aluminum foil lamination, excellent wettability. Excellent initial bonds.

RTFB 210 X This grade is modified version of RTFB 200 for better bonding to difficult substrates

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FLEXBOND-Solventless Two Comp.-1

TWO COMPONENT NCO OH CHARACTERISTICS

RTFB 101A/102A/103A

RTFB 101C

XX

Two Component general purpose Adhesive. Low viscosity an good wettability on metalized films.Highreactivity. 100:80

RTFB 101A/102A/103A

RTFB 102C

XX

Two Component pasteurizable Adhesive. Low viscosity an good wettability on metalized films and aluminum foils. Good reactivity. 100:60

RTFB 101A/102A/103A

RTFB 105C

XX

Two Component pasteurizable Adhesive. Low viscosity an good wettability on metalized films and aluminum foils. Longer Potlife. 100:50

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FLEXBOND-Solventless Two Comp.-2TWO COMPONENT NCO OH CHARACTERISTICS

RTFB 101A/102A

RTFB 202C/203C

XX

Two Component polyester based Adhesive. Mediumviscosity and good wettability on metalized films and aluminum foils. No evoparation on the machine, glossysurface. Good reactivity. Longer pot life

RTFB 100A

RTFB 212C/213C/222C/223C

XX

Two Component polyester based Adhesive. High viscosity and perfect wettability on metalized films and aluminum foils.

RTFB 101A/102A

RTFB 212C/213C/222C/223C

XX

Two Component polyester based Adhesive. High viscosity and perfect wettability on metalized films and aluminum foils.

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FLEXBOND-Solventbased Two Comp.

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TWO COMPONENT NCO OH CHARACTERISTICS

RTFB 750A/6100

RTFB 75C/80C/80CS

XX

Two Component general purpose Adhesive. Low viscosity an good wettability on metalized films and aluminum foils.

RTFB 40A

RTFB 45C

XX

Two-component polyester based adhesive, only for technical laminates with high thermal and high

chemical resistance.

100:10

PU based lamination adhesives –Curing time

Time Before

Slitting Sealing PAA decay Final filling

Solvent-basedAdhesives

12-24 hours

3 – 5days

7 – 14days

7 – 14days

SolventlessAdhesives

1 – 2days

5 – 7days

1 – 7days

5 – 7 days

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Flexible Packaging: – Requirements formigration-free laminates

Nomigration

food packagingbefore the adhesive fully curing

high monomercontaining adhesive

correct monomer contentcorrect storage time for curing

1. MDI migrates into food.2. MDI reacts with moisture.3. Formation of aromatic amine

→ T+, possibly carcenogenic

1. MDI migrates to surface2. MDI reacts with moisture3. Formation of aromatic amine4. reaction of MDI with aromatic amine to form

polyureafilm on surface of sealing layer.→ heat sealing problems

• no formation of aromatic amines• no heat sealing problems

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QUESTIONS?

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THANKS!

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