초록 ▼

This invention is a self-welding packaging film made by blending at least two ethylene polymers, one of the polymers having a melt flow substantially greater than any of the other polymers in the blend, and thereafter extruding a film from the blend. The film may be self-supporting or it may be an i

This invention is a self-welding packaging film made by blending at least two ethylene polymers, one of the polymers having a melt flow substantially greater than any of the other polymers in the blend, and thereafter extruding a film from the blend. The film may be self-supporting or it may be an inner layer in a multi-ply film. Preferred ethylene polymers for the blend are the ethylene-vinyl acetate copolymers wherein one copolymer has a melt flow of less than 5.0 and the other has a melt flow greater than 28.0.

대표청구항 ▼

A self-welding packaging film comprising: (a) a self-welding layer comprising a blend of at least two copolymers of ethylene-vinyl acetate, each copolymer having a different melt flow, the melt flow of one copolymer being less than 5.0 and the melt flow of another copolymer being greater than 28.0;

A self-welding packaging film comprising: (a) a self-welding layer comprising a blend of at least two copolymers of ethylene-vinyl acetate, each copolymer having a different melt flow, the melt flow of one copolymer being less than 5.0 and the melt flow of another copolymer being greater than 28.0; (b) a substrate layer comprising a cross-linked, heat shrinkable polymeric material said polymeric material selected from the group consisting of polyethylene and ethylene-vinyl acetate copolymers; and, (c) a layer having low gas permeability, the material for said layer being selected from the group consisting of: (1) copolymers of vinylidene chloride; (2) polyamides; (3) polyesters; (4) polyvinyl alcohol; (5) acrylonitrile copolymers; and, (6) hydrolized ethylene vinyl acetate copolymers; said substrate layer being located between the self-welding layer and the impermeable layer. The self-welding film of claim 6 wherein said tube is sealed transversely to form a bag. A multi-layer, self-welding packaging film comprising: (a) a self-welding layer comprising a blend of two polymers, (i) one polymer comprising the major portion of the blend and being selected from the group consisting of polyethylenes, ethylene-vinyl acetate copolymers, and ionomers having melt flows less than 5.0 and (ii) the other polymer comprising a minor portion of the blend and being selected from the group consisting of ethylene-vinyl acetate copolymers and ethylene terpolymers having melt flows greater than 28.0; and, (b) at least one additional film layer comprising a polymeric material selected from the group consisting of polyethylenes, ethylene-vinyl acetate copolymers, hydrolyzed ethylene-vinyl acetate copolymers, polyvinyl alcohols, copolymers of vinylidene chloride and vinyl chloride, polyamides, and acrylonitrile copolymers, said additional layer being heat shrinkable.