| 摘要 |
<p>The thermoplastic material, in sheet or tubular form, is chosen so that one layer has a softening point at least 20 degrees C lower than the other layers, to aid bonding with fibres of natural, synthetic, mineral or metallic origins. A metallic sheet is introduced to make the material waterproof and vapour-proof and to prevent odours penetrating through, for use in packaging foodstuffs. At least one thermoplastic layer may be shrinkable to make the sheeting suitable for shrink wrapping.</p> |
