| 摘要 |
<p>Packaging material with sealing edges consists of water-insoluble base material laminated with a cold water-soluble film of polyvinyl alcohol (PVAL) or starch-acetalized PVAL, arranged so that the water-soluble film overlaps to form welded bonding zones for sealing the pack, which can be resealed after opening by moistening the soluble film. Packaging with an envelope consisting of a foldable sheet of packaging material in the form of a laminate with at least two edges forming the bonding zone to make the envelope, in which: (a) the laminate comprises a water-insoluble base material (A) and a cold water-soluble film (B) consisting of polyvinyl alcohol (PVAL) with a degree of hydrolysis (DH) of 83-95 mol%, or acetals of PVAL with DH values (for liberation of OH groups from polyvinyl acetate) of 80-98 mol%, up to 50 wt% acetalized with starch; (b) the edges of the laminate layers are arranged with the water-soluble films overlapping one another to form welded bonding zones for sealing the pack; and (c) the opened pack can be resealed by moistening the soluble film at the edges. An Independent claim is also included for a process for the production of packaging material by bringing two strips of the above laminate together by means of rollers, so that two edges of the cold water-soluble film overlap to form bonding zones (for cold- or hot-welding).</p> |
