| 摘要 |
PURPOSE:To shorten a molding time by heating a slush mold filled with a thermoplastic resin powder by infrared rays. CONSTITUTION:A slush mold composed of a Ni-Cu system is heated for 90 sec while irradiated with infrared rays using an infrared gas burner of LPG combustion. The preheated mold is filled with a thermoplastic resin powder for 10 sec to perform skin molding for 10 sec to form the first resin layer in a sintered state and the mold is reversed to discharge the excessive thermoplastic resin powder out of the mold. A mixture of a heat-decomposition type foaming agent and the thermoplastic resin powder is allowed to fill the mold to perform foam skin molding for 10 sec and the second resin layer is formed on the first resin layer while the mold is reversed to discharge the excessive thermoplastic resin powder to the outside of the mold. Further, the mold is introduced in a hot air recirculation type furnace held to 250 deg.C to heat the molded resin for 20 sec to foam the same and subsequently put in a cooling chamber to eject cooling water to the mold for 20 sec before demolding. |
