| 摘要 |
PURPOSE:To provide a molded poyurethane having fine surfaces in RIM molding process for polyurethane by controlling the temperature of molds and the pressure in the molds. CONSTITUTION:In a RIM molding process for obtaining a molded polyurethane wherein at least two liquid raw components are mixed and injected into closed molds, the closed molds comprises at least two divided molds (an upper mold 1 and a lower mold 2) which can be clamped, and the temperature of one (for example the lower mold 2) of the divided molds where fine surfaces of a molded polyurethane are required is caused to be 5 deg.C higher than that of the other divided mold (for example the upper mold 1). After the liquid raw components has been injected into the closed molds, the clamping pressure will rapidly be reduced or a gas will be introduced into the closed molds. EFFECT:The adherence between surfaces of a molded article where its finess is required and inner surfaces of molds is improved to lessen uneveness or scars on the surface of the molded article due to the peeling, etc. |
