BiaxiallyBiaxially OrientedOriented BOPPBOPP BarrierBarrierFilmsFilms withwith thinthin EVOHEVOH LayersLayers

EuropeanEuropean MetallizersMetallizers Association, 9Association, 9thth+10+10thth ofof MarchMarch, 2006, 2006

Brückner Maschinenbau GmbH, Siegsdorf, GermanyDr. J. Breil, R. Lund, Dr. M. Wolf

© Brückner

Overview:

Introduction

Simultaneous biaxial orientation of different EVOH grades

LISIM PrincipleLISIM Laboratory Line: High flexibility in choice of

base materials and machine settings

Results and Summary

Possible Applications: Research Project „Thin Films“, costcomparisons

Path forward and Conclusion

© Brückner

High-Barrier-Materials Worldwide (in 1000 mt/ a)

89,9%13Na1<1PAA coated Film

10,7%20,0%11PVOH

20,7%3412,5%1610Glass coated film

10,4%559,2%3726EVOH Film

7,8%2057,2%152115Metallized Film

0,6%1641,5%160151PVDC Film

AGR2008AGR20042000Material

Introduction:

60% of film consumption is transparent films, 40% is metallisedOnly 5.3% of the total EVOH film consumption is oriented films

Source: Allied Development Corporation

© Brückner

Transparent bioriented OTR Barrier Films –Types and Advantages

Transparent biaxially oriented barrier films:

•Coated bioriented BOPP/ BOPET/ BOPA films:SiOx, AlOx, PVDC, Acrylics, EVOH a.o.

•PVDC barrier films, mainly blown film

•EVOH barrier films, mainly blown film and double bubble films(Exception e.g. Exxon Mobil Films), coated films

Advantages against e.g. metallized or non oriented films:

- Microwaveability- Product visibility- Design potentials- Deep drawability- Improved mechanical and optical properties- Thinner EVOH-layers

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Comparison of different Barrier Films

0,01

0,1

1

10

100

BOPET/PE

12/50

BOPPm/P

E20

/50

BOPA/PE

15/50

BOPP/PVDC

26

PE/PVDC/P

E25

BOPET/PVDC

BOPP-Sio

x/Bopp

20/20

BOPET/PE-E

VOH12

/50

BOPET-Alo

x/PE

12/50

BOPETm/P

E12

/50

BMS-Bar

rier 25

BOPET-Sio

x/PE

12/50

BOPA-Sio

x/PE

12/50

BOPET/Alu

/PE

12/7/

30

WV

TR

[g/m

²]O

TR

[cm

³/cm

²xd

xbar

]

OTR WVTR

© Brückner

Packaging Requirements for Barrier Films

600-3.00030-4.000Fresh Bakery Products

300-7007-11Fresh spec. cheese

2-41-3Fresh Meat c

2-420-40Fresh Meat b

10-3.00010.000-200.000Fruits, vegetables, salad

10-502-20Meat/ MAP

0,8-50,2-3Vacuum coffee

0,7-30,2-2Instant coffee

0,7-30,1-0,8Baby food

2-80,7-10Peanuts, snacks

WVTR [g/ m2 d]OTR [cm3/ m2 d bar]Packaging Good

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Simultaneous biaxial orientation of different EVOH grades

Source:

© Brückner

Fundamental Issues:Crystallisation behaviour of EVOHProperty overlap

●Crystallisation temperature overlaps the optimum orientationtemperature range of other polymers

Sequential orientation●Sequentiell orientation of EVOH is difficult due to the orientation

crystallisation and formation of microfibril structureSimultaneous orientation

●Simultaneous orientation at low stretching temperatures and/ or highstretching speeds subdues crystallization

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Processes for the production of biaxially oriented films

Sequential Stretching

Double-BubblePentagraph, Spindle, LISIM

Simultaneous Stretching

MDO - TDO

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LISIM® PrincipleLinearmotor Simultaneous Stretching technology

Clips

Cast-film

Simultaneous stretched film

Linear motors

© Brückner

Comparison Sequential / Simultaneous

LISIM® Simultaneous stretch. technology

123456789

10

Simultaneous Stretching

Useful area

MD

TD

TDOMDO

123456789

10

Sequential Stretching

MD

TD

Useful area

© Brückner

Comparison of mechanical film properties:Sequential / Simultaneous

268531303500TD

407030602000MDE-modulus[N/mm²]

1108255TD

5278200MDElongation atbreak [%]

208252290TD

310258140MDTensile-strength[N/mm²]

10 x 58 x 85 x 9Stretching ratio(MD x TD)

LISIM®Sequential

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LISIM® Pilotline

© Brückner

LISIM® pilot line for simultaneous stretching

70200250Net output (max.) [kg/h]

50150150Speed (max.) [m/min]

3 –55 –103 –5Stretching ratio TD

3 –56 –103 –6Stretching ratio MD

5 –253 –601 –150Thickness range [ µm ]

PAPPPETFilm types

Winder LISIM®

stretchingoven

IR-preheating

ExtrusionChill-roll

© Brückner

Laboratory Stretching Frame

Low amounts of material neededComparison of materials or mixturesData for upscaling experiments

mode: simultan bei 155°C 7,5x7,5; 400%/s

0,00

5,00

10,00

15,00

20,00

25,00

30,00

35,00

1 2 3 4 5 6 7 8

TD-Stretching Ratio [-]

Forc

e[N

]

E27_S

E32_S

E38_S

E44_S

E47_S

E44_N

E32_N

© Brückner

Lab-Stretching Unit

Production-Line

Pilot-Line

Advantages Demonstration of the LISIM® - Technology potential Basic R & D for film stretching Development of new film types Development of new components Production of Sample Rolls for Pre-Marketing

Method Evaluation of Process Window Optimisation of Film Properties Measurement of Stretching Forces Simulation with

FEM-Method Upscaling to

production scale

Upscaling Process

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7-layer BOPP/ EVOH barrier film (Ethylene content 27%)

Cross section of the stretched film:

Total

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Improved orientation through suppressionof crystallisation behaviour

7-Layer Film with EVOH ( Ethylen-Content 27% )Comparison Simultaneous/Sequential

simultaneous 5x5sequential 5x5

© Brückner

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

25 30 35 40 45 50

Ethylene content [%]

OT

R23

°C@

75%

RH

[cm

³x20

µm/m

²xd

xbar

] Stretching Ratio MDXTD=7x7Stretching Temperature=160°CStretching Speed= 400%/s

7-Layer Barrier FilmInfluence of EVOH-ethylene-content on OTR-Values

© Brückner

Influence of OTR on relative humidity for BOPP based filmsEVOH-thickness 1,5 µm

0

5

10

15

20

25

30

50 55 60 65 70 75 80 85 90 95 100Relative Humidity [%]

OTR

[cm

³/m²x

dxb

ar]

27%

SiOx

PVDC

© Brückner

Influence of the temperature on the OTR

0

5

10

15

20

25

30

35

40

45

0 20 40 60Temperature [°C]

OT

R[c

m³x

25µm

/m²x

dxb

ar] EVOH 30%

PVDC

© Brückner

Comparision with Customary Barrier Films

(38°C / 90% RH)4,554,2

WVTR [g/m²d]

(23°C / 75% RH)1,4320

OTR [cm³/m²dbar]

0,150,250,25Coefficient of Friction [µs]

160275275Tensile Strength TD [N/mm²]

211135135Tensile Strength MD [N/mm²]

180735003500Young‘s Modulus TD [N/mm²]

252622002200Young‘s Modulus MD [N/mm²]

22,52,5Shrink TD (120 °C, 5 min) [%]

433Shrink MD (120 °C, 5 min) [%]

1,61,11,6Haze [%]

919098Gloss [ ]

292526Thickness [µm]

(EVOH 27 % PE)PVOH coatedPVDC coated

7-LayerCommercial 2Commercial 1

© Brückner

7-Layer High Barrier s-BOPPCost Calculation in €/kg

1,48

3,50,52

0

0,5

1

1,5

2

2,5

3

3,5

4

€/kg

Production Costs

Material Costs

Market Price

© Brückner

Barrier Shrinkfilm

0

10

20

30

40

50

60

80 90 100 110 120 130 140Shrink temperature [°C]

Sh

rin

k[%

]

BMS-Barriershrink MD

BMS-Barriershrink TD

Barrier properties: OTR: 3.5 cm³/m² d bar (23°C / 75% r.h.)(before shrinkage) WVTR: 11 g/m²d (38°C / 90% r.h.)

© Brückner

Simultaneous biaxial orientation

Structure of a density reduced, opaque, barrier BOPP film

Density: 0,78 g/ cm3

OTR: 1,2 cm3/ m2 d bar 23°C/50% r.h.

WVTR: 1,2 g/ m2 d 23°C/0 - 85% r.h.

0,5 µmAdhesive Layer

1,4 µmEVOH

12,7 µmHomopolymer, CaCo3

30 µmGauge:

1,1 µmTerpolymer

0,5 µmAdhesive Layer

12,7 µmHomopolymer, CaCo3

1,1 µmTerpolymer

© Brückner

Summary of the EVOH biaxial orienting tests:

Sequential stretching is possible at higher Ethylene content of 44%

Simultaneous stretching possible with all types, even with only 24%ethylene content

High stretching speeds and/ or low stretching temperaturessuppress crystallization and thus „net structure“, good optics

Low OTR values

High flexibility due to choice of base material and machineadjustments:

●Shrink barrier films●Density reduced films

© Brückner

Source: Alcan Packaging Homepage

OTR [cm3/ m2 d bar] (25°C/ 50% r.h.)

WV

TR

[g/m

2d

](2

5°C

/100

%r.

h.)

SteelAluminiumGlass

PP-Ometallized

PETmetallized

Barrier values for different film systems

BMS(1.5µm)

© Brückner

Comparison of different BOPP barrier film systems

+++---- -Flex-Crack

++

+

-

-

+

+

+

AlOx

--++- -Retortability

++++Colour Index

-+--++VIS Light

Protection

0+-0++UV-

Protection

+++++++++Aroma

ooo++++WVTR

+++++++OTR

PVDCEVOH

opaque

EVOH

transp.

SiOxMetallized

++ + o - - -

© Brückner

Possible Applications: Research Project „Thin Films“

Database Simulation

Project coordination

Film-production

sequentialsimultaneous

End user

MetallizationSiOx

LaminationPrint

Adhesive

Packaging Packagingproperties

e.g. haptics

© Brückner

Definition of the targets

To demonstrate with selectedfilm systems

along the entire added valuechain

up to the final application,that a 50% reduction in materialis possible without significantlimitations of the technicalfunctionality

© Brückner

Motivations for Material Reductions

Cost savings for a 50% reduction in thickness: Up to 17% (Calculation IVV). Climbing raw material costs increase the share of the raw material on total

production costs and therefore enforce higher yields

The German Regulation of Packaging as well as the European packagingdirective 2004/12/EG make avoidance and material reduction a priority.

Demonstration of conformity with the European packaging directive accordingto DIN EN 13 427 ff.

Reduction of material input at retained functionality is in this norm an explicitlytermed criteria.

Source:

Why should there be a further material reduction in filmpackaging systems?

Cost savings and packaging law:

© Brückner

Example for substituted film laminates, cost comparison:Possible application: Peanuts

Duplex Compound1 Lamination Steps

Triplex Compound2 Lamination steps

Remark

212 €/ 1000 m2

76 µm

Sequential

PET 12µm //BOPETmet 12µm //PE-LD 50µm

Actual Standard

147 €/ 1000 m2Packaging costs

51 µmGauge

Process

Material

LISIM®

7-Layer EVOH 20µm // BOPP17µm / PE-LLD 13µm

Future Potentials

BOPET,12µm,Reversed Print

BOPET, 12µm, metal.Lamination

PE-LD, 50µmLamination

Transparentbarrier, 27% ELamination

Thin sealingfilm, 30 µm

Packaging cost reduction of ~ 28-32 % possible !

© Brückner

1-step simultaneous biaxial oriented PP/ EVOH/ PE

Additional cost reduction possibilities:„Integrated production process“:

0,5 µmAdhesive Layer

1,5 µmEVOH

10,5 µmHomopolymer

55 µmGauge:

30 µmPE

0,5 µmAdhesive Layer

10,5 µmHomopolymer

1 µmTerpolymer

© Brückner

Example for substituted film laminates:Possible application: Peanuts

1 Step ProcessTriplex Compound2 Laminating Steps

Remark

212 €/ 1000 m2

76 µm

Sequential

BOPET 12µm //BOPETmet12µm // PE-LD 50µm

Actual Standard

118 €/ 1000 m2Packagingcosts

55 µmDicke

Process

Material

LISIM®

7-Layer 20 µm / PE-LLD 30µm

Future Potentials

FilmtypwithoutLamination

BOPET,12µm,Reversed Print

Lamination

PE-LD, 50µmLaminationBOPET, 12µm, metal.

Packaging cost reduction of ~ 40-45 % possible !

© Brückner

Path Forward and Conclusion

Sample production for converting and packaging trials, discussionswith film converters and end users

Optimization of properties, e.g. shrink, mechanical properties and testsof further raw materials e. g. UV-Stabilizer or O2-scavengers

Replacement of PVOH and/or PVDC coated films (cost 4 Euro kg)

Possible application as shrink film (shrink 40% at 120°C@5 min)

Replacement of film laminates (PA/ PE, PET/ PE)

Penetration in the domain of metallized films (better flex crackresistance, less leakage, opaque films)

© Brückner

Thank you very much for your attention!