| 摘要 |
<p>A packaging film (10) is characterized by the inclusion of a layer (14) of a vinylidene chloride copolymer, e.g. VDC-methylacrylate copolymer, between at least two other layers (16, 18) which contain ethylene vinyl acetate, and optionally linear low density polyethylene. The film may be unoriented or molecularly oriented, may be heat set, and if oriented, optionally the film may be cross-linked. A process of making the cross-linked film includes the steps of joining the layers in face-to-face contact e.g. by coextrusion and of crosslinking the film after assembly of the vinylidene chloride copolymer layer into the structure. Cross-linking can be achieved by electron beam irradiation at a level of at least 1.5 megarads. The film can have a further layer or layers e.g. for heat sealing and for improving its abuse resistance, and can be made into a heat shrinkable bag suitable for packaging foodstuffs.</p> |
