| 摘要 |
<p>PURPOSE: To sterilize a product in a bag by using a heat shrinkable relatively gas impermeable thermoplastic packaging film, thereby holding at a high temperature for a long time. CONSTITUTION: A first surface sealing layer of a packaging film is selected at its first component of a blend from the group consisting of a propylene homopolymer and a copolymer, and at the other component from the group consisting of a butene-1 homopolymer and a copolymer. A second layer is made of a polymer selected from the group consisting of an ethylene homopolymer and a copolymer. A third low gas permeable layer is made of a polymer selected from the group consisting of a vinylidene copolymer and a hydrolyzed ethylene- vinyl acetate copolymer. A fourth outer surface layer is made of a blend specified with respect to the first layer. Thus, a multi-layer, heat shrinkable, thermoplastic packaging film which is heat sealed to itself to provide improved strong seals at a high temperature is provided.</p> |
