Molding method for eliminating fiber readout
AssigneeLibbey-Owens-Ford Co.
InventorWilliam R. Weaver
Life of this patent
Estimating the term…
Abstract
Fiber reinforced molded plastic articles, without fiber readout surface defects, are prepared in either resin transfer molding or reinforced reaction injection molding processes, by disposing a surface finishing film across the mold cavity prior to the insertion of the fiber preform and the injection of the curable polymeric precursor materials, thereby producing a finished article wherein the surface finishing film is bonded to the surface of the article filling the areas between those fibers near the surface which would otherwise cause fiber readout.
Claims22
A process for preparing a fiber reinforced molded plastic article, comprising the steps of:
- (A) providing a mold, including at least two cooperating mold sections, having a cavity therein for forming the fiber reinforced molded plastic article, wherein at least a portion of the mold cavity defines a mold cavity surface adjacent which a finished surface of the plastic article is to be molded;
- (B) disposing a surface finishing film across the mold cavity surface;
- (C) conforming the surface finishing film to substantially the configuration of the mold cavity surface;
- (D) positioning a fiber preform into the mold cavity having the surface finishing film conformed to the surface thereof, the fiber preform having substantially the same configuration as the mold cavity;
- (E) closing the mold;
- (F) injecting polymeric precursor materials into the mold cavity behind the surface finishing film, wherein the polymeric precursor materials fill the mold cavity and simultaneously:
- (i) impregnate the fiber preform to form a molded fiber preform;
- and
- (ii) deform the surface finishing film into intimate contact with the mold cavity surface;
- and
- (G) curing the polymeric materials inside the mold, thus allowing the surface finishing film to maintain intimate contact with the mold surface while bonding the surface finishing film o the molded fiber preform;
- whereby the surface finishing film provides a finished surface, whose outside shape matches the inside of the mold surface, and is free from fiber readout, on the fiber reinforced molded plastic article.
A process for preparing a fiber reinforced molded plastic article, comprising the steps of:
- (A) providing a mold, including at least two cooperating mold sections, having a cavity therein for forming the fiber reinforced molded plastic articles, wherein at least a portion of the mold cavity defines a mold cavity surface adjacent which a finished surface of the plastic article is to be molded;
- (B) disposing a surface finishing film across the mold cavity surface, the film having a thickness from about 0.5 to about 15 mils, and selected form the group consisting of polyesters and polyurethanes;
- (C) conforming the surface finishing film to substantially the configuration of the mold cavity by applying a vacuum to the mold cavity surface;
- (D) positioning a glass fiber preform into the mold cavity having the surface finishing film conformed to the surface thereof, the fiber preform having substantially the same conformation as the mold cavity;
- (E) closing the mold;
- (F) injecting polymeric precursor materials, selected from the group consisting of precursors for the preparation of polyurethanes, polyesters and crosslinked epoxy resins, into the mold cavity behind the surface finishing film, wherein the polymeric precursor materials fill the mold cavity and simultaneously:
- (i) impregnate the fiber preform to form a molded fiber preform;
- and
- (ii) deform the surface finishing film into intimate contact with the mold cavity surface;
- and
- (G) curing the polymeric materials inside the mold, thus allowing the surface finishing film to maintain intimate contact with the mold surface mold while bonding the surface finishing film to the molded fiber preform;
- whereby the surface finishing film provides a finished surface, whose shape matches the inside of the mold surface, and is free from fiber readout, on the fiber reinforced molded plastic article.
Dependencies are inferred from the claim text.