| 摘要 |
<p>A sandwich composite comprises (A) a core of a closed-cell, oriented foam based on a polystyrene which has a tensile modulus of at least 10,550 kg./cm2., and (B) two thermoplastic skins which are heat formable at 50 degrees-230 degrees C. and have a tensile modulus of at least 10,550 kg./cm2. One skin contains at least 75% polystyrene and the other at least 75% polyvinyl chloride. In particular one skin is of toughened polystyrene or an ABS polymer, and the other is of a vinyl chloride (94%)/vinyl acetate (6%) copolymer. Uses are as water-impermeable and grease-resistant packaging for food or cosmetics. Containers can be easily thermoformed.</p> |
