PRODUCTION OF SEAT PAD FOR VEHICLE HAVING VENT HOLE

摘要

PURPOSE:To obtain a thick-walled seat pad of high quality for a vehicle by performing foam molding in such a state that a solidified layer of wax held to a solid state at molding temp. and melted at predetermined temp. or higher is formed on the surface of a heatable pin and heating the surface of the pin to the m.p. of wax or higher after molding. CONSTITUTION:Wax having relatively high m.p. is applied to the surface of the pin 4 planted in a lower mold in such a state that upper and lower molds are opened and cooled to form the solidified layer 7 of the wax on the surface of the pin 4 in such a state that a Nichrome wire 5 is embedded in the solidified layer 7. Next, the upper and lower molds are closed and a foamable resin raw material is injected in the cavity formed by the molds and foamed under heating to mold a seat pad 10 for a vehicle having a predetermined shape. When a thick-walled seat pad is obtained, the Nichrome wire 5 is energized to heat the surface of the pin 4 to temp. equal to or lower than the m.p. of the wax and near to the temp. in the molds. At the time of demolding, the upper mold is opened and the Nichrome wire 5 is energized at the same time to heat the surface of the pin 4 to the m.p. of the wax or higher to melt the solidified layer 7 of the wax and the pin 4 is contracted in its diameter by the quantity corresponding to the molten wax and the wax acts as a lubricant.