| 摘要 |
<p>PURPOSE:To obtain a flat and thick-walled high hollow injection molded article having uniform wall thickness and excellent surface appearance by preventing the formation of a stripelike projection on the inner wall of a hollow part. CONSTITUTION:After initial cavity vol. is expanded, the low foamable molten resin 5 in a mold cavity 2 is cooled to such a state that a part of the resin reaches solidifying temp. but the other part thereof does not reach the solidifying temp. and, in this state, an inert pressure fluid is introduced into the mold cavity 2 under pressure to expand the vol. of the cavity 2. Since the insoluble pressure fluid introduced under pressure flows in a uniformly dispersed state from a place where the interior of a molded object becomes a foamed layer 4 and the molten resins of the opposed surfaces of the foamed layer are not mutually pulled to be stretched, the foamed layer 4 is cleanly divided into two parts without forming a stripelike projection.</p> |
