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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
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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
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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
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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
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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:
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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
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Comparison Sequential / Simultaneous
LISIM® Simultaneous stretch. technology
123456789
10
Simultaneous Stretching
Useful area
MD
TD
TDOMDO
123456789
10
Sequential Stretching
MD
TD
Useful area
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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.)
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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
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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
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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)
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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 - - -
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Possible Applications: Research Project „Thin Films“
Database Simulation
Project coordination
Film-production
sequentialsimultaneous
End user
MetallizationSiOx
LaminationPrint
Adhesive
Packaging Packagingproperties
e.g. haptics
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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
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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:
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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 !
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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
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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 !
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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)
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Thank you very much for your attention!