| 摘要 |
<p>A laminate comprises a substrate and a high frequency weldable surface layer of a copolymer (I) comprising 70-90 mol.% ethylene and 10-30 (esp. 14-18) mol% vinyl acetate. Teh substrate is pref. a polyolefin, polyester or polyamide, esp. polyethylene or polypropylene. Mfr. is by co-extrusion of the two layers. The film is used for welded packs which can be peeled open. Sachets can be prepd. by heat sealing the outer edges of the pack permanently, filling and then welding with high frequency to form a seal which can be peeled open. The seal can be formed without use of additional materials, overwrapping or using elevated temps. which may damage the content. The seal is stable and tight so that packaged goods have improved storability and aroma, moisture content and taste of tobacco are maintained. Packs can also be used for food, screws and electrical parts.</p> |
