US 4,608,220 A · Method of forming composite material articles

Abstract

Improvements in manufacturing composite material articles. The use of male molds in forming such articles has the problem of requiring large tolerances for the outer dimensions of the articles. The use of female molds has the problem of inaccurate forming of highly contoured inner surfaces. The invention produces an accurately formed inner surface by molding material against a male mold, and outer dimensions within close tolerances by curing the material in a female mold. A male caul (34) is positioned on a male mold (30). A preplied stack (32) of composite material is supported on a blanket (36) and held in position against caul (34) with caul (34) and mold (30) in an inverted position. Stack (32) is heated. A vacuum causes blanket (36) to mold stack (32) against caul (34). Mold (30) is rotated 180.degree., and stack (32) is allowed to cool. A female mold surface (43) is placed into contact with formed stack (32). Male mold (30) is moved away, leaving caul (34 ) and formed stack (32) in female mold (42). Stack (32) is cured in female mold (42), preferably by a vacuum bagging operation.

Claims18

Dependent claims

A method of manufacturing an article from a plastic material, comprising:

providing male mold means having a male mold surface with a shape essentially identical to the desired shape of the inner surface of the completed article;
forming said material onto said mold means to conform said material to said shape, to accurately form the inner surface of the article;
providing a female mold having a female mold surface with a shape and dimensions essentially identical to the desired shape and dimensions of the outer surface of the completed article, and placing the female mold surface into contact with the formed material on the male mold means;
curing the formed material in the female mold, including exerting through flexible means essentially uniform pressure on the material to urge it against the female mold surface, to accurately control the outer dimensions of the article;
and
while placing the female mold surface into contact and curing the formed material, maintaining said shape of the inner surface of the article.

3 more elements

A method of manufacturing an article from a plastic material, comprising:

providing a male mold having a male mold surface with a desired shape;
providing a male caul that conforms to said shape, and positioning the caul on the mold in contact with said surface;
forming said material onto the caul positioned on the mold to conform said material to said shape;
providing a female mold having a female mold surface with a shape and dimensions essentially identical to the desired shape and dimensions of the outer surface of the completed article, and placing the female mold surface into contact with the formed material on the caul and the male mold;
moving the male mold away from the caul, and leaving the formed material and the caul in the female mold;
and
curing the formed material in the female mold between the caul and the female mold surface, including exerting pressure on the caul to exert essentially uniform pressure on the material and urge the material against the female mold surface.

4 more elements

Dependencies are inferred from the claim text.

Method of forming composite material articles

Life of this patent

Method of forming composite material articles

Life of this patent

Abstract

Claims18