Laminated skin-foamed core sandwich structures and method for their preparation
AssigneeTenneco Polymers, Inc.
InventorIm K. Park
Life of this patent
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Abstract
Laminated skin-foamed core sandwich structures characterized by an excellent stiffness and load-bearing capability to weight ratio are prepared by heating in a closed mold a sandwich construction that comprises skin layers that comprise a thermoplastic polymer having a glass transition temperature in the range of 75.degree. to 85.degree. C. and reinforcing fibers and a core that comprises a thermoplastic polymer that is compatible with the polymer in the skin layers and that has a glass transition temperature that is 10.degree. to 20.degree. C. lower than that of the polymer in the skin layers and a blowing agent at a temperature sufficient to fuse and expand the core and to fuse the skin layers and bond them to the expanded core.
Claims15
The method of forming reinforced skin-foamed core sandwich structures that comprises the steps of
- A. forming a sandwich construction comprising
- 1. two skin layers, each comprising at least two plies of a thermoplastic polymer composition having a glass transition temperature in the range of 75.degree. to 85.degree. C. and at least one ply of reinforcing fibers,
- 2. a core composition comprising a thermoplastic polymer composition having a glass transition temperature in the range of 60.degree. to 70.degree. C., said glass transition temperature being 10.degree. to 20.degree. C. lower than that of the resin in the skin layers and said polymer being compatible with that in the skin layers, and a chemical blowing agent, and
- B. heating said sandwich construction in a closed mold at a temperature sufficient to fuse and expand the core and to fuse the skin layers and bond them to the expanded core.
A reinforced skin-foamed core sandwich structure that is the product obtained by
- A. forming a sandwich construction comprising
- 1. two skin layers, each of which comprises at least two plies of a thermoplastic polymer composition having a glass transition temperature in the range of 75.degree. to 85.degree. C. and at least one ply of reinforcing fibers and
- 2. a core comprising a thermoplastic polymer composition having a glass transition temperature in the range of 60.degree. to 70.degree. C., said glass transition temperature being 10.degree. to 20.degree. C. lower than that of the polymer in the skin layers and said polymer being compatible with the polymer in the skin layers, and a chemical blowing agent and
- B. heating said sandwich construction in a closed mold at a temperature sufficient to fuse and expand the core and to fuse the skin layers and bond them to the expanded core.
Dependencies are inferred from the claim text.