| 摘要 |
PURPOSE:To obtain a sheet in oil-containing high molecular materials which has been hard conventionally to manufacture by subjecting an oil-containing high molecular material to extrusion molding with a high molecular material having no compatibility therewith layered on its back and front and then removing back and front layers after molding. CONSTITUTION:An oil-containing high molecular material is extruded with an oilless high molecular material having no compatibility therewith layered on its back and front simultaneously in a sheet die. After molding into a sheet through a sheet molding machine, the oilless high molecular material layers are removed. For example, an oil-containing high molecular material is fed through a flow passage 50, an oilless high molecular material is fed through flow passages 60, 70 to extrusion, and thus a sheet 10 is obtainable in 3-layer construction with a center layer 1 coming in oil-containing high molecular material and front and back layers 2, 3 in oilless high molecular material. Since the portion in contact with the wall of die 4 is covered with the oilless high molecular material in this case, the extrusion molding is free from oil percolation and hence is carried out smoothly. |
