| 摘要 |
<p>There is provided a multi-layered foamed article. The foam article has a layer of foam material on either side of an inner peel layer disposed roughl y in the middle of the foam. The portion of the foam in closest proximity to the peel layer is subjected to the greatest amount of heat during extrusion forming mostly large open cell foam. The foam near the surface of the multiplayer foam article is cooled by the atmosphere or contact with cooling surfaces and comprises most ly small closed-cell foam. There is also provided a method for making a multi- layer foamed article by co-extruding an inner peel layer sandwiched between two expanded layers of a foam material. Each of the expanded foam layers on eith er side of the peel layer of the article is easily peeled or stripped from the peel inner layer and the multi-layer article is converted into a foamed article with absorbing characteristics on one side and non-absorbing characteristics on the other side. Thus, the foam is predominantly open-cell on one side of the structure a nd predominantly closed-cell on the opposing side. The open-cell portion of the article is highly absorbent and easily soaks up liquids. The closed cell portion of the foam article acts as a waterproof layer preventing liquid from moving al l the way through the thicknessof the foam. After blowing the polymer melt, the extrusion product comprises a foam article with a peel layer disposed roughl y in the middle of the foam. A preferred embodiment of the multi-layer article is polystyrene foam for the two outer layers and a polyethylene film as the inn er peel layer.</p> |
