US 5,262,105 A · Method for molding hollow shaped bodies

Abstract

Molding a hollow shaped body which has a skin made of a synthetic resin and a hollow portion therein by a mold block provided with a mold cavity in the shape of the hollow shaped body, a tub into which an excess amount of the synthetic resin can flow and a small flow path communicating between the mold cavity and the tub. The process includes forming the skin of the hollow shaped body by injecting a molten synthetic resin into the mold cavity to fill up the cavity. Thereafter, a gas is introduced into the injected synthetic resin to thereby form the hollow portion. The gas injection forces a part of the synthetic resin out of the mold cavity and into the tub through the small flow path.

Claims8

Dependent claims

A method of molding a molding strip having a main frame and an end cap with a hollow portion therein, which comprises the steps of:

preparing said main frame of said molding strip so as to have a passage at a head portion thereof, while preparing a mold block so as to have a protrusion to form a small flow path by partially narrowing said passage;
disposing said main frame in said mold block so as to define a cavity for molding said end cap, said cavity being formed between the head portion of said main frame and said mold block;
injecting a molten synthetic resin into said cavity at least until a front end portion of said molten synthetic resin flow enters into said small flow path;
and
introducing a gas into said injected synthetic resin to thereby form said hollow portion, while simultaneously allowing a part of said injected synthetic resin to flow out from said cavity to said passage of said main frame through said small flow path.

2 more elements

Dependencies are inferred from the claim text.

Method for molding hollow shaped bodies

Life of this patent

Method for molding hollow shaped bodies

Life of this patent

Abstract

Claims8