Method of manufacturing thermoplastic resin container
AssigneeToyo Seikan Kaisha, Ltd.
InventorsTsutomu Iwasaki, Masahito Kogure, Hideo Kawasaki, Yasushi Hatano
Life of this patent
Estimating the term…
Abstract
In a method for manufacturing a thermoplastic resin vessel, in which a cup-shaped vessel is thermally formed from a thermoplastic resin sheet by a plug, the method including the steps of: pre-forming a portion of the thermoplastic resin sheet corresponding to an orifice portion or a flange portion of the cup-shaped vessel; and clamping the pre-formed portion of the thermoplastic resin sheet to accomplish the forming. According to the manufacturing method, thickening of a vessel bottom part and warpage of the flange portion can be improved.
Claims3
A method for manufacturing a thermoplastic resin vessel, comprising the sequential steps of:
- 1) fixing an outer periphery of a portion to be formed to a cup-shaped vessel of a thermoplastic resin sheet by pre-clamped molds;
- 2) pre-forming an inner portion of the fixed portion of the thermoplastic resin sheet by a plug, wherein a portion corresponding to an orifice portion or a flange portion of the cup-shaped vessel is drawn;
- 3) clamping the portion corresponding to the orifice portion or the flange portion of the cup-shaped vessel further by an upper mold and a lower mold;
- 4) drawing an inner portion of the clamped portion further by the plug;
- 5) pneumatically forming the drawn portion into a shape of the lower mold heated at not less than a crystallization temperature of the thermoplastic resin sheet, and thermally fixing the sheet;
- and
- 6) decompressing an inside of the formed article to contract the formed article into a shape of the plug which is a final vessel shape, and cooling the article.
Dependencies are inferred from the claim text.