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US 6,322,735 B1Granted
Method for molding thermoplastic resin
AssigneeAsahi Kasei Kogyo Kabushiki Kaisha
InventorsHiroshi Yamaki, Yoshimasa Matsuura, Hiroshi Kataoka
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Abstract
A method for molding a thermoplastic resin by filling a molten thermoplastic resin into a mold which comprises carrying out the molding of the resin while reducing the solidification temperature of the resin surface which contacts with the mold during the step of filling the resin. According to this molding method, the state of the mold surface can be faithfully transferred to molded articles.
Claims14
In a method for molding a thermoplastic resin comprising the steps of:
- filling a mold cavity having a formed surface with a gas;
- filling said thermoplastic resin in a molten state into said mold cavity;
- cooling and solidifying said thermoplastic resin thereby forming an article of said thermoplastic resin;
- and
- taking the article of said thermoplastic resin out of the mold, the improvement comprising the steps of
- using as said thermoplastic resin a resin consisting of an amorphous thermoplastic resin;
- using carbon dioxide as said gas, thereby dissolving carbon dioxide that is at the surface of the amorphous thermoplastic resin in the mold cavity and reducing the solidification temperature of the amorphous thermoplastic resin surface which contacts with the mold;
- and
- pressing said resin to the surface of the mold for transferring the form of the surface of the mold to the surface of said amorphous thermoplastic resin, before the step of cooling and solidifying said thermoplastic resin.
6 more elements
Dependencies are inferred from the claim text.