Antiblocking structure/properties

General Description Ethylene Vinyl Acetate (EVA) Copolymer is a copolymer resin ranging in vinyl acetate content from 7.5 wt% to 33 wt%. DuPont Elvax and Equistar Ultrathene grades vary by vinyl acetate content. Some grades are available with antiblock and slip additives. The vinyl acetate units in the copolymer modify the basic polyethylene structure and its properties. The addition of vinyl acetate to polyethylene provides lower sealing temperature, increased flexibility, improved optical properties, greater adhesion, increased impact, and puncture resistance. 

Unmodified multilayer film with heat-sealable skin layers has an inherently high coefficient of friction and film-to-film blocking properties. Therefore, slip additives and antiblocking particulates are traditionally added to the film structure to lower the coefficient of friction and provide improved machinability to produce, for example, food packages. 

The structured boehmite provides essentially equivalent film antiblock and film clarity properties as antiblocking quality silica, when both are employed in a 1 mil blown LDPE film at a 0.25% loading level. This equivalent film perfor-... 

---