pagev dsm presentation pa6 in film

DSM Engineering Plastics

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PAGEV Turkish Plastics Industry Congress - 2006

Improved performance with PA6 in multilayer barrier films

PA6 with modified rheology

Ted Brink

Application Development Extrusion


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OverviewOverview

• Introduction• Why PA6 in food packaging• Trends in barrier films• Akulon XP – high productivity PA6• Conclusion


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Evolution

DSM: over a century of successful DSM: over a century of successful transformationstransformations

Chemical engineering

Polymer technology

Fine chemicals

Material science

Mechanical engineering

Biotechnology

Technological competences

Life Science Products

Coal

Fertilizers

Petrochemicals

Performance Materials

Bioterials / Biologics

1902 1930 19701950 1990 2000


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DSM today DSM today

• Globally active “multi-specialty” chemical company• active on 5 continents, more than 200 locations• approximately ~ 21.000 employees

• Leadership positions in ~75 % of the portfolio• R&D spending ~ 5 % of sales• Solid balance sheet

• € 8 billion sales in 2005

Life Science Products

Performance Materials

Industrial Chemicals

Other

DSM NutritionalProductsDEP

DSM Engineering Plastics€705 million sales in 2005

1300 employees


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DEP: partner for innovative film conceptsDEP: partner for innovative film concepts

• Today one of the leading PA6 film resin suppliers• New plant started with 18.000 t/y capacity in 2001• Additional capacity of 35.000 t/y in 2005• Introduction of Akulon XP• Portfolio of resins for the film industry

NOH


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DSM product portfolio for film applicationsDSM product portfolio for film applications

• Akulon PA6• Akulon PA66• Akulon XP high productivity PA6• Yparex PE-g-MAH tie resin• Stanyl PA46 high heat resistant for specialty films• Arnitel COPE breathable film

portfolio of standard gradesfor cast and blown film


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PA6 in barrier filmPA6 in barrier film

• food packaging (> 80 %)• meat• cheese• fish• sausage casings

• non-food applications• release films for SMC• medical film• protective bubble film• agricultural film


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Why PA6 for film in food packaging?Why PA6 for film in food packaging?

• Oxygen barrier• Aroma and flavour barrier• Mechanical protection• Puncture resistance• Printability• Transparency• Heat resistance


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Trends in PA barrier filmTrends in PA barrier film

• Use of BOPA• Improvement of barrier properties

• nanocomposites• oxygen scavengers• blends

• Active & intelligent packaging• More complex film structures (Akulon

XP)• Down gauging – improved productivity (Akulon XP)• Shift from PA6.66 to PA6


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Examples of coextruded multilayer structuresExamples of coextruded multilayer structures

cheese/meat

tie layer

PE

PA

fresh meat

PEtie layer

EVOH

tie layerPP

PA

PA


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Multilayer film with viscosity matchMultilayer film with viscosity match

desired situation

However, in practice ideal situations are rare


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Multilayer film with viscosity mismatchMultilayer film with viscosity mismatch

Viscosity mismatch:• limits flexibility

• more grades required

• different film structures on one machine not always feasible

• quality risk• more material use

polymer with higher viscosity


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Viscosity curves of LDPE and PA6Viscosity curves of LDPE and PA6

10

100

1000

10000

0.01 0.1 1 10 100 1000

shear rate [1/s]

visc

osi

ty [

Pa.

s]

LDPE

Akulon F132


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Polymer flow in a coat hanger diePolymer flow in a coat hanger die

Coat hanger die:• different flow rates in the die• multilayer structures require viscosity match

to prevent interface disturbances


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processing window

Standard materials result in interfacial Standard materials result in interfacial instabilityinstability

Rheology mismatch PA6 and LDPE

10

100

1000

10000

0.01 0.1 1 10 100 1000

shear rate [1/s]

visc

osi

ty [

Pa.

s]

PA6

LDPE

leads easily to problems

poor elasticity and viscositymatch creates wave effect

one component missing at edges


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Viscosity curves of unmodified materialsViscosity curves of unmodified materials

10

100

1000

10000

0.01 0.1 1 10 100 1000

shear rate [1/s]

visc

osi

ty [

Pa.

s] LDPE

Akulon F126

Akulon F130

Akulon F132

Akulon F136


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wide processing window

The Akulon XP solutionThe Akulon XP solution

10

100

1000

10000

0.01 0.1 1 10 100 1000

shear rate [1/s]

visc

osi

ty [

Pa.

s]

Minimizes the difference in melt viscosity and melt elasticity of coextruded materials.

Result: widening of processing window

Akulon XP exhibits:enhanced

shear-thinning behaviour:

• less motor power at high rpm

• higher zero shear viscosity

LDPEMFI 1.9

Akulon XP


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The “trick”: branching of the PA6 chainThe “trick”: branching of the PA6 chain

Random long chain branching of PA6• increase of zero-viscosity• flow behaviour becomes more shear thinning• enhanced melt strength in elongational flow

Furthermore:• branching allows very high molecular weights, not possible

with linear PA6


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Effects of branched polymersEffects of branched polymers

Linear polymers show Newtonian flow behaviour

Short chain branching:• reduction of density• minor influence on rheology

Long chain branching:• strong influence on rheology• enhanced shear thinning• strain hardening


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Effects of branchingEffects of branching

Control of viscosity• melt stability (uncontrolled polymerization)• gels !!

Controlled branching is realized by:• branching agent: addition of a trifunctional compound• to prevent formation of gels: addition of a monofunctional

compound


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Neck-in on cast film and extrusion coatingNeck-in on cast film and extrusion coating

maximum die width

chillroll

standard PA6 Akulon XP

extruded film width


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Web stability in cast film and extrusion Web stability in cast film and extrusion coatingcoating

die

chillroll

standard PA6 Akulon XP

web instability


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Improved layer thickness distributionImproved layer thickness distribution

thin sections are quality riskand determine

barrier and mechanical properties

classical PA6

Akulon XP

edge trim edge trim


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The thermoforming processThe thermoforming process

film

mould

IR heater

vacuum


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The thermoforming processThe thermoforming process

film

mould

IR heater

vacuum


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Thermoforming issuesThermoforming issues

thin corners

Issues:• thin corners• limited elongation


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Thermoforming behaviourThermoforming behaviour

• drawing is influenced by:• temperature• stretch ratio• drawing rate• polymer viscosity• molecular structure• crystallization rate


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Thermoforming of COPA and PA6Thermoforming of COPA and PA6

• advantage COPA is lower crystallization rate• drawing of PA6 can be improved by:

• keep the sheet as amorphous as possible• addition of amorphous polyamide• addition of COPA

• improved thermoformability of Akulon XP compared to regular PA6• more even thickness in the corners• higher elongation possible


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Effects of Akulon XP in multilayer cast filmEffects of Akulon XP in multilayer cast film

• less neck-in

• better web stability• improved layer thickness

distribution• wider processing window

• shear thinning

waste reduction (side trims)

improved machine efficiency

higher production speed

less material use

better quality

less down-time

higher output

less motor power at high rpm

higher output possible


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Akulon XP propertiesAkulon XP properties

• improved processing efficiency• cast film• blown film• extrusion coating• thermoforming• stretching

• barrier properties same as classical PA6• mechanical properties comparable to classical PA6• crystallization behaviour unchanged


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Advantages of Akulon XP in non-film applicationsAdvantages of Akulon XP in non-film applications

• extrusion blow moulding• improved melt strength

• monofilaments• improved roundness at large diameters

• stock shapes• improved symmetry in tubes with large diameters due to high melt stabilty

• convoluted tubes• improved dimensional stability at low diameters tube


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ConclusionConclusion

Akulon XP is a new polyamide 6 with improved processing behaviour, which can lead to lower conversion costs and improved film properties


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İLGİNİZ İÇİN TEŞEKKÜR EDERİM

pagev dsm presentation pa6 in film

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