| 摘要 |
<p>Unitary molded plastic hinged article and method of making in which a fluid molten mixture of heat softenable resin and a blowing agent in substantially unfoamed condition is introduced into an expandable mold cavity to fill the cavity and the mold is expanded to allow foaming of the resin to form at least one foam cored article section while the resin adjacent the mold surface is still fluid and in which the hinge structure is formed by a member adapted to form a thin, flex portion and portions transitional from the thickness of the flex portion to the thickness of a cored article section, the shaping member being slidably disposed in an aperture in the mold with portions of the walls of the aperture exposed within the mold cavity at the time the molten mixture is introduced and the exposed portions of the walls being wiped by the shaping member when the mold is expanded. Cooling of the mixture by the mold prevents development of blowing gas for expansion of the resin adjacent the mold and shaping member to provide an unfoamed surface for the article and an unfoamed flex portion of the hinge structure with a progressive increase in central foam in the transitional portions from the flex portion to the cored article sections.</p> |
