Ethylene Vinyl Alcohol Copolymer

Ethylene vinyl alcohol (EVOH) is a copolymer of ethylene and vinyl alcohol. These materials are highly crystalline and are produced with various levels of ethylene content. 

EVOH film has many desirable properties that are summarized as follows: 

• Antistatic Properties: Since EVOH resin is a highly antistatic polymer, dust is prevented from building up on the package when used as a surface layer. 

• Luster and Transparency: EVOH resins produce a high gloss and low haze, resulting in outstanding clarity characteristics. The use of EVOH resin as the outer surface of a package provides excellent sparkle for improved package appearance. 

• Printability: With an OH group in its molecular chain, the EVOH resin surface can be easily printed without special treatment.

• Resistance to Oil and Organic Solvents: EVOH resins resist oils and organic solvents, makingthem particularly suitable for packaging oily foods, edible oils, mineral oils, agricultural pesticides, and organic solvents. 

• Weather Resistance: EVOH resins display excellent weatherability. Even when exposed to outdoor conditions, the polymer retains its color and does not become yellow or opaque. Mechanical property changes are minimal, demonstrating an overall high resistance to weather effects. 

• Permeability: EVOH resins offer outstanding gas (oxygen, carbon dioxide, nitrogen, and helium) barrier properties, and maintain their barrier property over a wide range of humidity. The oxygen-barrier properties of EVOH vary according to the ethylene content in the polymer. Packages containing EVOH resins can effectively retain fragrances and preserve the aroma of the contents within the package. At the same time, undesirable odors are prevented from entering or leaving the package. 

Film processing methods include monolayer film extrusion (blown or cast), coextruded film extrusion (blown or cast), coextrusion blow-molding, profile coextrusion, and coating. Applications and uses: Rigid packaging for entrees, edible oils, juice, cosmetics, pharmaceuticals, heating pipe, automotive plastic fuel tanks, and packaging for condiments and toothpaste. Flexible packaging: Processed meats, bag-in-box, red meat, cereal, pesticides, and agrichemicals.