What is EVOH film used for?
EVOH is an ethylene vinyl alcohol polymer that mainly consists of carbon, oxygen and hydrogen. The EVOH film is used in our multilayer technology as a barrier layer and protective layer and is of central importance in the food packaging industry.
What is an EVOH layer?
Ethylene vinyl alcohol copolymer (EVOH) barriers comprise a family of extrudable plastic barrier materials with excellent barrier properties for oxygen and a variety of other gases and volatile products (flavor barrier).
Is EVOH a good moisture barrier?
When compared to other common films, EVOH is considered to have superior barrier properties. However, when exposed to moisture, EVOH loses its good gas barrier properties.
What is EVOH resin?
Ethylene-vinyl alcohol copolymer or EVOH is a flexible, crystal clear, and glossy thermoplastic copolymer produced through alcoholysis of poly(vinyl acetate). In commercial EVOH resins, the vinyl alcohol content typically various between about 55 and 75 mole percent.
What is EVOH made of?
Ethylene–vinyl alcohol (EVOH) is a copolymer of ethylene and vinyl alcohol. The structure of EVOH is shown in Fig. 10.4 and has a CAS number of 26221-27-2. These materials are highly crystalline and are produced with various levels of ethylene content.
Who makes EVOH?
Kuraray has been manufacturing and marketing ethylene vinyl-alcohol copolymers (EVOH) under the name EVAL™ since 1972, and remains the world leader in EVOH production and market development.
Where is EVOH made?
Industrial production Nippon Gohsei produces EVOH under the trade name Soarnol. It has production sites in Mizushima, Japan; La Porte, Texas in the USA; and at Salt End, Hull, England. Chang Chun Petrochemical produces EVOH under the trade name EVASIN.
What is the density of EVOH?
1.12 – 1.24 g/cc
| Physical Properties | Metric |
|---|---|
| Density | 1.12 – 1.24 g/cc |
| Moisture Absorption at Equilibrium | 1.50 – 8.50 % |
| Moisture Vapor Transmission | 0.360 – 3.10 cc-mm/m²-24hr-atm |
| Water Vapor Transmission | 14.28 – 217.1 g/m²/day @Temperature 37.8 – 37.8 °C |
What is Coco-injection molding?
Co-injection molding takes advantage of a characteristic of injection molding called fountain flow. As the cavity is filled, the plastic at the melt front moves from the center line of the stream to the cavity walls.
What are the applications of coinjection machine?
When polyolefins are processed, a gastight material like EVOH is used as a barrier layer in the core. Another special application of coinjection is interval injection molding, used to produce a marbled appearance in molded parts.
What are some examples of co-injection molding applications?
Examples of co-injection applications include: The use of plastic regrind as the core material, while maintaining surface finish quality by using virgin plastic as the skin material. The use of a core material that is thermally more stable, to increase the thermal resistance of a part.
What is the marbling effect in injection molding?
Because of repeated switching between the two components during the injection process, a reproducible marbling effect is created when molding parts with complex profiles, and a tiger stripe pattern in the case of simple profiles.