Improving the performance of bulk
packaging of liquids through the use of
modified ethylene vinyl alcohol (EVOH)
Edgard Chow (Technical Manager)
Robert Armstrong (TS&D Director)
Kuraray America Inc.
Pasadena, TX
SPE Polyolefins Conference
Houston TX
February 2012
Agenda
• EVAL™ EVOH
– Typical applications
– Properties
• Liquid packaging formats
– Bag-in-box
– Intermediate bulk containers
– Flexitants
• Improving the properties of EVOH
– Conventional EVOH
– Amorphous EVOH
– Elastomer modified EVOH
What is EVOH?
Higher density
Higher melt point
Higher barrier
Ethylene mol %
More flexible
More orientable
24
27
32
35
38
44
48
a semi-crystalline thermoplastic
and a random copolymer of
Ethylene and Vinyl ALcohol
(CH2-CH2)m
(CH2-CH)n
OH
EVOH Protects Food
(Outside of packaging)
Oxygen, off-odors, off-flavors, other contaminants
Flavor, aroma, vitamins, modified atmosphere gases
(Inside of packaging)
Versatility of EVOH






Oxygen barrier
Aroma barrier
Vitamin protection
Flavor preservation
Solvent barrier
Hydrocarbon barrier
Toluene
Xylene
Oxygen
Mint
Vitamin C
Coffee
Agenda
• EVAL™ EVOH
– Typical applications
– Properties
• Liquid packaging formats
– Bag-in-box
– Intermediate bulk containers
– Flexitants
• Improving the properties of EVOH
– Conventional EVOH
– Amorphous EVOH
– Elastomer modified EVOH
The Iconic BIB Application
• Advantage over glass
– More functional
• Single cup dispensing convenience
• No headspace
• Can stay open up to 21 days
– More sustainable*
• 85% less packaging/landfill waste
• 53% less CO2 emissions
Source: www.betterwinesbetterworld.com/
Wine BIB Requirements
• High barrier
– 0.5 ~ 0.8 cc/m2.day.atm @ 20°C, 65%RH
– EVAL™ L171B = 27mol% Et. EVOH
• High abuse resistance
Transportation Abuse
Potential Outcome
Standard Test Method
•
•
•
•
•
•
Up/down motion in land
Side/side motion in sea
Pinhole formation
OTR deterioration
ASTM F193-92
ASTM D3985
Adopted Wine Industry Specifications
•
•
•
0 pinholes max. after 200 gelbo flex cycles
2 pinholes max. after 400 gelbo flex cycles
OTR < 1.0 cc/m2.day.atm
Evaluation Method
ASTM F193-92 Reapproved 2004
45 CPM, full flex condition
Gelbo flex testing
ASTM D3985
20°C, 65%RH
Oxygen transmission rate
Evaluation of Market Samples
 Inner layer : PE40
PE inner liner
Barrier outer liner
 Outer layer : (in) PE30//VM-PET12//EVA40 (out)
 OTR : 1.0cc/m2/day/atm, 2.8cc/m2/day/atm
 WVTR : 5.7g/m2/day
 Inner layer : PE90
 Outer layer : (in) PE40/Tie/EVOH6/Tie/PE60 (out)
 OTR : 0.8cc/m2/day/atm
 WVTR : 2.6g/m2/day
 Inner layer : PE40
 Outer layer :
(in)
EVA15/Tie/EVOH6/Tie/EVA7 //ON10//PE30 (out)
 OTR : 0.6cc/m2/day/atm
 WVTR : 5.9g/m2/day
Test conditions: OTR:20ºC/65%RH, WVTR:40ºC/90%RH
Evaluation of Market Samples
Oxygen Transmission Rate After Gelbo Flex
BIB Applications (3 – 20L)
Olive Oil
Cola Syrup
Drums (200L)
Aran Packaging
Bluesept55®
Juice
concentrate
Coffee
concentrate
IBC(1000 – 1500 L)
Sealed Air Cryovac
Entapack®
Flexitank Market
• Typically in the 12,000 to 36,000L range
• Must comply with the Code of Standards by the Container
Owners Association
• The flexitank market size is ~500,000 units
• Recent 7-layer installation by Raven Industries
Flexitank Benefit
• 20 ft Container payload
– 15% higher than IBCs
– 44% higher than drums
Source: www.unedecom.com
Flexitank Market
• EPT Wine-Pac™ has a third inner liner of EVOH film
• OTR of 0.4 cc/m2.day
• Applications
– Food & beverage: wine, oils, juice concentrates, etc.
– Cosmetics: detergents, bleaching solutions, cleaners, etc.
– Industrial chemicals: adhesives, paints, biofuels, fuel additives, etc.
Source: http://eptpac.com
Trends with big bags
• The larger the bag, …
– the lower the barrier requirements
• Surface area to volume ratio factor
– but the higher the physical abuse on the bag
• Normal stresses induced by higher loads
• Use of multiple liners similar to BIB is also practiced
3 – 5L
retail BIB
3 – 20L
institutional
BIB
200 – 1500L
IBC
12000 – 36000L
Flexitank
High Barrier Flexitank Challenges
• Limited experience base producing large, thick
bags with thin EVOH layers
– Larger dies, longer residence time in the melt demand
improved thermal stability
• Use of higher ethylene grades
• Selection of EVAL 7-series
– Longer time for the bubble to reach its finished
geometry
• Higher ethylene grades have a lower recrystallization
temperature
– Higher flex crack resistance
• Use of softer modified grades
Agenda
• EVAL™ EVOH
– Typical applications
– Properties
• Liquid packaging formats
– Bag-in-box
– Intermediate bulk containers
– Flexitants
• Improving the properties of EVOH
– Conventional EVOH
– Amorphous EVOH
– Elastomer modified EVOH
Failure Mechanism of Pinhole Formation
Fatigue Cracking
From radical generation on to micro-crack generation
Inhibition of crack growth is critical to improve
flexible crack resistance
EVAL Technologies for Liquid
Packaging
Type
Technology
Illustration
EVAL
Conventional
Good
EVAL SP
Amorphous EVOH
Better
EVAL FS
Elastomer modified
EVOH
Best
Domain-matrix
Flex crack
resistance
Film Pilot Equipment
•
Materials
–
–
–
–
–
Cast film production
Toyo-seiki
20mm metering screw
300mm coat hanger die
Blown film production
Brampton Engineering
7-layer, 6” pancake die
Sclair FP120 C8-LLDPE
Ultrathene UE624000 18% vinyl acetate EVA
Admer NF498A LLDPE-based tie resin
Dupont Byner 3861 EVA-based tie resin
Various types of EVAL
•
Gelbo flex conditions
–
45 CPM, full flex, room temperature
Effect of EVOH Grade and Thickness
Number of gelbo cycles to create one (1) pinhole
Coex blown film structure: LLDPE/Tie/EVAL/Tie/LLDPE = 36 / 5 / X / 5 / 36μm
Number of cycles to 1 pinhole
1200
1000
1000
1000
900
900
800
800
700
600
400
400
300
300
200
30
0
20μm
Mono
4μm
6μm
15μm 20μm 20μm
Coex
F171
Mono
4μm
6μm
15μm 20μm
Coex
FS101
Effect of Structure Stiffness
Number of gelbo cycles to create one (1) pinhole
• Film structure
– 20μm monolayer cast film
– 90μm blown film: LLDPE/LL-Tie/EVAL/LL-Tie/LLDPE = 36/5/8/5/36μm
– 90μm blown film: LL+EVA/EVA-Tie/EVAL/EVA-Tie/LL+EVA = 36/5/8/5/36μm
Flex Crack Resistance of EVAL FS101
Number of gelbo cycles to create one (1) pinhole
•
Structure: 90μm blown film: LLDPE/LL-Tie/EVAL/LL-Tie/LLDPE = 36/5/8/5/36
16
14
Average Number of Pinholes
14
12
10
9
F171(32)
8
J171(32)
6
4.6
3.8
4
2
0
1
0
3.2
1
0
500
1000
Number of Gelbo Cycles
2000
FS101(32)
More developments underway
Number of gelbo cycles to create one (1) pinhole
• Structure: 20μm monolayer cast film
EVAL Grades for Liquid Packaging
Type
Technology
Flex crack
resistance
Grades (et.mol%)
EVAL
Conventional
Good
L171(27)
F171(32)
H171(38)
E171(44)
EVAL SP
Amorphous EVOH
Better
SP521(27)
J171(32)
XEP-1035(38)
EVAL FS
Elastomer
modified EVOH
Best
FS101(32)
XEP-1273(32)
Summary
• EVOH has excellent barrier properties
• EVOH has great flex crack resistance when
coextruded with softer polyolefin resins
• The use of EVOH in BIB is established but grades
with improved the flex crack resistance for larger
bags such as flexitanks have been developed
• We can sample any of the mentioned grades upon
your request
Thank You!
Presented by:
Edgard Chow
phone (281) 474-1558
edgard.chow@kuraray.com
Acknowledgement
Mr. Wataru Hirose (EVAL R&D Japan)