| 摘要 |
<p>Laminates consisting of a metal foil 2 having an uncoated surface which has been directly heat sealed to the surface 4 of a polymeric web 1 by an outer surface 4 of the web, the outer surface 4 of the web 1 consisting of a blend of an ethylene/vinyl acetate copolymer and an additive which embrittles the copolymer at room temperature. Packages produced by directly heat sealing metal foils 2, preferably aluminum foil, to polymeric webs 1 having the specified outer surface have exhibited peel strengths, for example in the range of from 2 to 6N/15mm, which enable press through packages to be produced which do not peel open when tablets are pushed through them but will peel when in the form of pouches (see Figure 5). The additive may comprise poly-di-pentene, a polyterpene, a -methyl styrene resins or modified aromatic resins. The polymeric web may comprise an intermediate layer 5 comprising a blend of a polyolefin and an incompatible additive which reduces the internal cohesion of the polyolefin. Incompatible additives may comprise polypropylene, polybutene-1, chalk, talc, titanium dioxide, barium sulphate or magnesium sulphate.</p> |
