| 摘要 |
1335098 Thermosetting resin impregnated laminates SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ NV 17 Aug 1971 38524/71 Addition to 1266097 Heading B5N An article impregnated with thermosetting resin is produced by impregnating a sheet having an open-cell foam structure, e.g. polyurethane foam, with a curable thermosetting resin, e.g., an epoxy resin, applying a layer of fibrous reinforcing material, e.g., a glass fibre mat, to a side of the impregnated foam sheet, compressing the foam sheet and fibrous reinforcing layer to the extent that resin is expelled from the sheet into the fibrous reinforcing layer to impregnate this layer with resin throughout its thickness, and allowing the resin in the sheet and layer to curr whilst maintaining the compression, the compression of the assembly taking place in an enclosed space and being effected by the expansion of a foaming composition, e.g. of a polyurethane, rubber or urea-formaldehyde resin. The foaming composition may be in direct contact with the impregnated foam sheet or separated therefrom by one or more intermediate layers, e.g., of paper, thermoplastic material or glass fibres. The compression may be effected in a mould preferably having two moulding surfaces extending parallel to each other either straight or curved and treated with a mould release agent, the assembly being placed in the mould with fibrous reinforcing layer against the mould surface and the foam forming composition introduced by pouring or spraying as an unfoamed or partly foamed liquid. An assembly may be placed on each side of the mould and the mould cavity left between the two assemblies filled with foam forming compositions. Curing may be effected at room temperature or at an elevated temperature. |
