edgard chow (technical manager) robert armstrong (ts&d director) kuraray america inc. pasadena,...
TRANSCRIPT
Edgard Chow (Technical Manager)
Robert Armstrong (TS&D Director)
Kuraray America Inc.
Pasadena, TX
SPE Polyolefins Conference
Houston TX
February 2012
Improving the performance of bulk packaging of liquids through the use of modified ethylene vinyl alcohol (EVOH)
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
a semi-crystalline thermoplastic and a random copolymer of
Ethylene and Vinyl ALcohol
(CH2-CH2)m (CH2-CH)n
OH
3235
27
384448
More flexibleMore orientable
Ethylene mol %
Higher densityHigher melt point Higher barrier
24
What is EVOH?
EVOH Protects Food
Oxygen, off-odors, off-flavors, other contaminants
Flavor, aroma, vitamins, modified atmosphere gases
(Outside of packaging)
(Inside of packaging)
Oxygen barrier Aroma barrier Vitamin protection Flavor preservation Solvent barrier Hydrocarbon barrier
Versatility of EVOH
Coffee
Oxygen
Toluene Vitamin CMintXylene
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/
• High barrier– 0.5 ~ 0.8 cc/m2.day.atm @ 20°C, 65%RH– EVAL™ L171B = 27mol% Et. EVOH
• High abuse resistance
• Pinhole formation• OTR deterioration
Wine BIB Requirements
• Up/down motion in land• Side/side motion in sea
• 0 pinholes max. after 200 gelbo flex cycles• 2 pinholes max. after 400 gelbo flex cycles• OTR < 1.0 cc/m2.day.atm
Potential OutcomeTransportation Abuse
Adopted Wine Industry Specifications
• ASTM F193-92• ASTM D3985
Standard Test Method
Evaluation Method
ASTM F193-92 Reapproved 200445 CPM, full flex condition
ASTM D3985 20°C, 65%RH
Gelbo flex testing Oxygen transmission rate
Evaluation of Market Samples
Inner layer : PE40
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/dayTest conditions: OTR:20ºC/65%RH, WVTR:40ºC/90%RH
PE inner liner
Barrier outer liner
Evaluation of Market SamplesOxygen Transmission Rate After Gelbo Flex
BIB Applications (3 – 20L)Juice
concentrate
Coffee concentrate
Cola SyrupOlive Oil
Drums (200L) IBC(1000 – 1500 L)
Sealed Air CryovacEntapack®
Aran Packaging Bluesept55®
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
Inhibition of crack growth is critical to improve flexible crack resistance
EVAL Technologies for Liquid Packaging
Type Technology Illustration Flex crack resistance
EVAL Conventional Good
EVAL SP Amorphous EVOH Better
EVAL FS Elastomer modified EVOH
Domain-matrix
Best
Film Pilot Equipment
• Materials– 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
Blown film productionBrampton Engineering7-layer, 6” pancake die
Cast film productionToyo-seiki
20mm metering screw300mm coat hanger die
• Gelbo flex conditions– 45 CPM, full flex, room temperature
Coex blown film structure: LLDPE/Tie/EVAL/Tie/LLDPE = 36 / 5 / X / 5 / 36μm
Effect of EVOH Grade and ThicknessNumber of gelbo cycles to create one (1) pinhole
Effect of Structure Stiffness
• 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
Number of gelbo cycles to create one (1) pinhole
Flex Crack Resistance of EVAL FS101
• Structure: 90μm blown film: LLDPE/LL-Tie/EVAL/LL-Tie/LLDPE = 36/5/8/5/36
Number of gelbo cycles to create one (1) pinhole
More developments underway
• Structure: 20μm monolayer cast film
Number of gelbo cycles to create one (1) pinhole
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
AcknowledgementMr. Wataru Hirose (EVAL R&D Japan)