EVAL™ Resins – The Better Barrier for Fuel Containment

EVAL™ Resins – Essential for Environmental Performance

EVAL™ BARRiERs MAkE thE DiffEREncE

Why do so many plastic fuel tanks have an EVAL™ barrier layer? The key reason is that EVAL™ resins’ fuel barrier properties are superior to any other conventional polymer. EVAL™ is about 4,400 times greater than HDPE and many times greater than that of Nylon 6. By preventing gas permeation through the wall of the tank, the EVAL™ gas barrier minimizes fuel vapor emissions. With emissions regulations becoming more stringent around the world, the EVAL™ layer makes compliance possible, cost-effective and reliable.

ADVAntAgEs thRoughout thE fuEL systEM

In addition to their application in automotive, marine and small engine fuel tanks, EVAL™ resins are the ideal solution for a number of fuel system components. EVAL™ functions as an outstanding barrier to HFC, CO2, N2 and H2, which makes it the better choice for reducing emissions in air conditioning system parts, hydrogen fuel cell applications, fuel lines and filler pipes.

EVAL™

usED in AutoMotiVE AppLicAtionsAround the world, multilayer plastic fuel tanks and fuel system components have become the preference of automobile designers and manufacturers; and for good reason. Plastic exhibits several advantages over metals, such as its light weight and ease of fabrication. And with the unparalleled barrier performance of EVAL™ resins from Kuraray, these tanks are as good for the environment as they are for the industry.

• With unparalleled fuel barrier properties, the EVAL™ barrier layer keeps fuel vapor within the walls of the fuel system, out of the atmosphere, and in compliance with strict EPA: Tier 1, Tier 2, Tier 3 (pending) and CARB: LEV I, LEV II, PZEV, LEV III emission standards.

• Highly resistant to hydrocarbons, oils and organic solvents, EVAL™ resins remain durable over time, preventing the evaporation of chemicals.

• EVAL™ resins provide good long-term thermal stability, even in high-temperature environments.

• Easy to process, EVAL™ resins can be coextruded with HDPE and other component layers on conventional equipment in a single step. A range of grades is available to meet diverse processing requirements.

• Global reach: manufactured and sold by the EVAL™ companies of Kuraray in the Americas, Europe and Japan/Asia.

thE EVAL™ REsins ADVAntAgE

1

typicAL co-ExtRuDED six-LAyER stRuctuRE

In comparison with the other treatments used as barrier material for HDPE fuel tanks, multilayer co-extrusion with EVAL™ is the leading technology that meets U.S. Environmental Protection Agency (EPA) and the California Air Resource Board (CARB) emission standards. Kuraray has already prepared the next generation of EVAL™ barrier technology, capable of taking tank shell performance well beyond PZEV requirements.

E10 BARRiER coMpARison of VARious MAtERiALs

thE EVoLution of AutoMotiVE fuEL tAnks

Almost 40 years ago, most fuel tanks were made of steel. However, steel tanks have their disadvantages: they are heavy, increase risk of leakage and corrosion, and cannot be fabricated into unique shapes. The auto industry looked for an alternative and turned to plastic.

The first plastic fuel tanks were introduced in Europe during the 1960s and later came to the U.S. due to the implementation of the CARB LEV I legislation. Blow-molded monolayer fluorinated fuel tanks had been the preferred technology in the U.S. The development of the slosh test, however, called for a technology that would give consistent performance over time. This led to the use of six-layer fuel tanks with an EVAL™ barrier layer, which is now the dominant plastics technology used in the market.

EVAL™

usED in fuEL tAnks

ADHESIVE 2%

3%

ADHESIVE 2%

HDPE 38%

HDPE 15%

REGRIND 40%

EVAL™ RESIN BARRIER

0

250

500

750

1,000

3,000

3,500

4,000

4,500

GC Based Method

E10

Tra

nsm

issi

on

Rat

e (g

.20

mu

/m2.

day

)

M10

0

F10

1

PA6

POM

ETFE

20

HD

PE

PA12

1 3

500

100

4,000

800

2

• Stronger and lighter, reducing overall car weight and improving fuel efficiency

• Safer — less likely to perforate and leak in crash

• More space-efficient — can be molded into complex geometries to optimize space

• Economical to produce — regrind is recycled and reused

• Cleaner — less waste is produced in the workplace environment

MuLti-LAyER pLAstic fuEL tAnks stAnD up to stEEL

EVA

L™ R

esin

s –

The

Alte

rnat

ive

Mad

e P

oss

ible

3

EVAL™ UsEd in fuEL tAnks

Safer Than Steel Plastic fuel tanks increase safety in the event of a crash. Unlike metal fuel tanks, plastic tanks can bend and flatten rather than tear, rupture and spill gasoline. Because they are more likely to stay intact, they significantly reduce the likelihood of fuel leakage that can cause a fire or explosion.

More Design Flexibility Plastic fuel tanks allow car designers to optimize the space available for the fuel tanks because of their shape adaptability.

typical Applications typical structure (in/out)

Fuel tanks (automotive)

HDPE/tie/EVAL™/tie/regrind/HDPE + masterbatch

Small-engine gas tanks (lawn mowers, chainsaws, ATVs)

Jerry cans, marine tanks

EVAL™ UsEd in fuEL LinE AppLicAtions

Plastic fuel lines are lightweight, cost-effective and allow complex geometrics, which makes them very appealing for manufacturers. Plastic fuel lines containing an EVAL™ barrier layer provide exceptional permeation resistance, meeting stringent international emission regulations (EURO, EPA and CARB) and durability characteristics. Plastic fuel lines enable manufactures to optimize the cost, space, weight and fit parameters while surpassing safety and emission requirements.

typical Application typical structure (in/out)

Fuel lines PA 6/EVAL™/PA 6/tie/PA 12

EVAL™

AppLicAtions

• Plastic-lined tanks containing an EVAL™ layer weigh much less than steel tanks

• The barrier against hydrogen is 1,000 times better than that of polypropylene

ADVAntAgEs of using EVAL™ LAyERs in

MuLtiLAyER pLAstic hyDRogEn tAnks

4

EVAL™ UsEd in pipE AppLicAtions

Compared to their metal equivalents, multilayer plastic fuel pipes are lighter in weight and more flexible than conventional steel pipes. This gives manufacturers greater freedom in the positioning of the fuel tank underneath the car to optimize safety and design while reducing the overall weight of the vehicle.

The barrier properties of an EVAL™ layer add superior barrier performance to the fuel pipes and to the entire fuel system. An EVAL™ layer in a multilayer fuel pipe reduces the fuel vapor permeation to an absolute minimum, meeting strict international emission standard regulations.

typical Applications typical structure (in/out)

Fuel filler pipes HDPE/tie/EVAL™/tie/regrind/HDPE + masterbatch

Underground fuel pipes EVAL™/tie/HDPE

EVAL™ UsEd in hyDRogEn fuEL cELLs

Hydrogen fuel cells are a promising technology that can provide energy for stationary applications, for mobile use in transport and even power generation for a laptop or camcorder. Hydrogen fuel cells are environmentally friendly; they do not produce polluting emissions or greenhouse gasses.

In the coming years, it is expected that fuel cells will be commercially introduced into several transportation and utility power markets. It is very important that the fuel cells are reliable and provide outstanding barrier against hydrogen gas. EVAL™ EVOH resins can be used to ensure very low-hydrogen gas permeation in hydrogen storage and fuel-cell systems.

Ethylene mol% h2gtR cc/m2.d.atm for 0.1 mm | 20°c, 0% Rh

EVAL™ 24 mol% 3

EVAL™ 32 mol% 6

EVAL™ 44 mol% 40

Polypropylene 2,000

• Tanks containing an EVAL™ layer are environmentally friendly

• Because of EVAL™’s excellent barrier properties, less raw material is required for the same result

5

EVAL™ Resins – Right for Our Environment

AutoMotiVE EVApoRAtion EMission REguLAtions

Regulation Regulatory Agency

Emission Allowed on Light-Duty Vehicle

tested item useful Life Required

Tier 1 EPA 2,000 mg/test for 3 day diurnal Entire vehicle 100,000 miles

Tier 2 EPA 950 mg/test for 3 day diurnal Entire vehicle 120,000 miles

Tier 3 EPA pending

LEV I CARB 2,000 mg/test for 3 day diurnal Entire vehicle 100,000 miles

LEV II CARB 500 mg/test for 3 day diurnal Entire vehicle 150,000 miles

PZEV CARB

350 mg/test for 3 day diurnal

54 mg/test for 3 day diurnal

Entire vehicle

Fuel System

150,000 miles

LEV III – Option 2 CARB300 mg/test for diurnal with E10 fuel

Entire vehicle 150,000 miles

7

EVAL™

EnViRonMEntAL REguLAtions

• Permeation Specification: 1.5 g/m2/24hr @ 28°C

• Test fuel is E10

• Procedure is based on weight loss

• 20 week soak at 25°C with fuel

Estimated value using EVAL™ F101 is less than 0.5 g/m2/24 hr

sMALL tAnk – EpA REguLAtions

8

EVAL™

BARRiER pRopERtiEsEVAL™ Resins Have Excellent Resistance to Standard & Flex Fuels

pLAstic fuEL tAnk shED MEAsuREMEnt

pERMEAtion Vs. thicknEss

conDitions:

Test fuel: Phase II and CARB LEV III E10 <Preliminary Specification>

Soaking at 40°C for 20 wks with refreshing fuel every 4 wks

Tank Volume: 47 L

SHED-Tank Shell only without components0

2

4

6

8

10

Per

mea

tio

n (

mg

/24

hrs

)

SHED Measurement by CARB LEV III E10

PHASE IIEVAL-F32mol%

CARB E10EVAL-F32mol%

CARB E10EVAL-L27mol%

CARB E10EVAL-M24mol%

EVAL Thickness

2%4%

0.00 10 20 30 40 50 60 70

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

Tota

l Per

mea

tio

n, E

10 (

g/m

2.d

ay)

EVAL THICKNESS (microns)

F101M100

9

EVAL™ ethylene vinyl alcohol (EVOH) copolymer resins are characterized by their outstanding gas barrier properties and by their excellent process ability.

The key to this balance of characteristics is the combination of the proper copolymerization ratio of ethylene to vinyl alcohol. Kuraray’s unique proprietary manufacturing process has produced the world’s widest available range of EVOH grades.

EVAL™ M type offers superior barrier performance for automotive applications.

EVAL™ L type has very low ethylene content and is suitable as an ultra-high barrier grade in several applications.

EVAL™ f type offers superior barrier performance and is widely used for automotive, bottle, film, tube and pipe applications.

EVAL™ c type can be used for high-speed co-extrusion coating and cast flexible applications.

EVAL™ h type has a perfect balance between high barrier properties and long-term run stability and is especially suitable for blown film.

EVAL™ E type has a higher ethylene content which allows for greater flexibility and even easier processing. Different versions have been specially designed for cast and blown film as well as for pipe.

EVAL™ g type has the highest ethylene content, making it the best candidate among standard EVAL™ grades for stretch and shrink film applications.

EVAL™ sp resins are a new family of resins that combine the gas barrier performance of traditional EVOH resins with improved orientability. This “softer” EVOH is ideal for applications where orientation is key and more flexible barrier polymer is needed.

50

49

48 mol%

47

46

45

44 mol%

43

42

41

40

39

38 mol%

37

36

35 mol%

34

33

32 mol%

31

30

29

28

27 mol%

26

25

24 mol% M

L

F

C

H

E

G

EVAL™ is a registered trademark of Kuraray Co. Ltd.

hEADquARtERs

2625 Bay Area Blvd., Suite 600 Houston, TX 77058

Tel: (800) 423-9762 Fax: (281) 204-4622

pLAnt

11500 Bay Area Blvd. Pasadena, TX 77507

www.kuraray.us.com

Rev 7/2012