| 摘要 |
PURPOSE:To facilitate a molding of a product, causing a resin inner core layer to flow smoothly by providing the thin skin layer resin having viscosity higher than that of inner core resin at molding, and being easily separable after molding, while coating the inner surface of dies with lubricant. CONSTITUTION:Thermoplastic resin is molded by compression molding, extrusion molding or rolling, coating the inner surface of dies with lubricant. The thermoplastic resin has at least three layers, and at least one skin layer being in contact with an inner core resin layer has higher viscosity at molding than that of the core resin layer. The skin layer resin and the core resin are easily separated after molding and are antiadhesive. The thermoplastic resin is molded such that the skin layer thickness is equal to or less than 1/10 of the core layer thickness. For instance, the thick material 16 composed of the core layer 17 and the skin layer 18 with said property at the temperature equal to or higher than the transition temperature of thermoplastic resin glass and equal to or lower than the melting point of said resin glass, is put on compression molding dies 15 whose inner surfaces are covered with lubricant and are heated. When the compression molding dies 15 compress the thick material 16, said material 16 is biaxially orientated. After its cooling and solidification, the resin product is taken out from the dies, and when the skin layer is separated from the product, the excellent biaxially orientated molded product may be obtained. |
