| 摘要 |
<p>Method for molding plastic articles by forming a parison on a core within an injection mold, cooling the internal and external walls of the parison thus formed by heat transfer through the core and the injection mold, transferring said core to a delay position for permitting redistribution of heat from the interior of the parison to the exposed walls to obtain a more uniform temperature just above the material's glass transition temperature, and subsequently transferring said core to an expansion mold for expanding same, the cooling and heat redistribution permitting a greater degree of orientation of the polymer chains of the formed articles. Preferably, the apparatus for practicing the process includes injection and expansion molds supported in such a relation as to permit a substantial time interval between injection and expansion of the parison.</p> |
