| 摘要 |
This invention relates to an improved injection foam molding method in which a foamable mixture of molten synthetic polymer resin and a chemical blowing agent in unfoamed condition is injected into a gas-pressurized expandable mold having a mold section movable for expanding the mold cavity to a position in which the surface of that section is in registry to the surface of another mold section, in which process the mold is filled under conditions resisting foaming of the material prior to filling of the mold and a novel controlled time sequence effective to form a fine mold crease line is employed in releasing the gas pressure and expanding the mold to allow foaming of the mixture into conformity with the mold surface. |
