| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a multi-layer polyolefin resin-based foamed sheet, consisting of at least three layers, which is almost free from thickness irregularities and suitably of a broad width for plate flatness, with a large proportion of a surface layer. SOLUTION: The polyolefin-based resin containing a foaming agent is kneaded/melted by an extruder, and the molten mixture is extruded into a foamed sheet from an extruder die. Further, the polyolefin-based resin is kneaded and melted by the extruder and the molten mixture is extruded to the surface of the foamed sheet from the extruder die as a laminated surface layer. In this method, the foamed sheet and/or the foamed sheet with the laminated surface sheet are shaped and cooled while being held by a pair of endless steel belts at 60°C to a temperature near the melting point of the polyolefin-based resin as a sheet inlet part temperature and at 0 to 20°C as a sheet discharge part temperature. Thus the multi-layer polyolefin resin-based foamed sheet is manufactured. COPYRIGHT: (C)2009,JPO&INPIT |
