Method of manufacturing formed articles, equipment for practicing same, and formed articles manufactured by the method
AssigneeToyo Seikan Kaisha, Ltd.
InventorsKazumi Hirota, Kikuo Matsuoka
Life of this patent
Estimating the term…
Abstract
A thin sheet having a low rigidity is drawn while being depressed over the radiused corner of a die by elastic force or hydrostatic force to obtain a formed article whose sidewall part and flange part have no wrinkles. The force is applied through an annular rigid body on which elastic is exerted. The hardness of the rubber is preferably approximately 70 to 85 in accordance with ASTM D 2240 Durometer A. A laminate not more than about 200 .mu.m in thickness and consisting of a thermoplastic resin film, aluminum foil and a heat-sealable resin film is drawn into a formed article or a container which is light in weight and suitable for containing foods, for instance.
Claims11
A drawing machine comprising:
- a punch, and a die having a cavity formed therein corresponding to said punch and having a radiused corner, said punch for drawing a thin sheet having a relatively low rigidity into said cavity in said die to manufacture a formed article, and
- means comprising a depressing member having an end surface of the depressing member being formed substantially conforming to the shape of the radiused corner which is disposed movable around said punch in such a manner that said end surface of said depressing member is brought to cooperate with said radiused corner with said thin sheet therebetween into contact with a surface of said thin sheet which is opposite to a face of said thin sheet which is brought into contact with the radiused corner of said die and said sheet is depressed by said depressing member substantially throughout the drawing.
Dependencies are inferred from the claim text.