초록 ▼

A surface-reinforced lightweight article is described, which includes a honeycomb structure whose sidewalls are reinforced by an expanded foam. The article can be manufactured by laying a fibrous third layer, such as several layers of dry tissue paper backed by a layer of dry fiberglass cloth, on th

A surface-reinforced lightweight article is described, which includes a honeycomb structure whose sidewalls are reinforced by an expanded foam. The article can be manufactured by laying a fibrous third layer, such as several layers of dry tissue paper backed by a layer of dry fiberglass cloth, on the walls of a mold, laying a second layer of multi-cell honeycomb-like material against the third layer, and laying a finely porous first layer such as tissue paper over the second layer. Foamable plastic is poured in the mold over the three layers and the mold is closed. As the plastic foams and expands, it forces the three layers into a tight sandwich and permeates the layers to reinforce them. Specifically, expanded foam in the cells of multi-cell honeycomb-type material braces the honeycomb sidewalls against collapse, to greatly increase the strength and rigidness of the article. It is found that the density of foam is much greater in the cells than in the core of the article that lies inside the layers, so that high strength foam lies where it is needed while keeping the core lightweight.

대표청구항 ▼

A surface-reinforced article, comprising: a core of foam material having a first outer side; a surface region of said article which includes a porous but flow-through resistant first layer lying on said outer side of said core, a multi-cell honeycomb-type sheet structure lying outside said first lay

A surface-reinforced article, comprising: a core of foam material having a first outer side; a surface region of said article which includes a porous but flow-through resistant first layer lying on said outer side of said core, a multi-cell honeycomb-type sheet structure lying outside said first layer and a fibrous third layer lying outside said honeycomb-type structure; said first layer, said cells of said honeycomb-type sheet structure, and said fibrous third layer each being impregnated with the same foam material as said core, and the foam material in said core, first layer, cells, and third layer is of the same composition throughout.