MANUFACTURE OF LAMINATED SHEET

摘要

PURPOSE:To remove voids contained in resin efficiently and control the generation of thin spots developed by the voids on a molded laminated sheet by pressurizing the sheet with a low initial pressure to the state of a given reduced pressure and then pressurizing with a pressure higher than the initial pressure. CONSTITUTION:A laminated material is pressurized with a low initial pressure up to the state of given reduced pressure and then pressurized with a pressure higher than the initial pressure in the manufacturing method of a laminated sheet in which a plurality of laminated material consisting of piled up inner layer materials, resin impregnating bases, metal foils and the like are heated and pressurized under the pressure reduced atmosphere. A plurality of piled up resin impregnating bases are disposed between hot platens to vacuum atmosphere and a laminated sheet is manufactured by heating and pressurizing under the pressure reduced atmosphere. The degree of vacuum is 100Torr or less, and lowering pressure is 5-150kg/cm<2>, while molding temperature is 100-200 deg.C and molding time is around 30-100min. The initial pressure is 5-10kg/cm<2> and the pressure is applied until the degree of vacuum comes up to 500-100Torr.