1. Field of the Invention
The invention relates to a method of producing an article of thermosetting resin.
2. Prior Art
In British Pat. No. 1,266,097 a method of producing an article of thermosetting resin is proposed, which comprises impregnating a sheet having an open-cell foam structure with a curable thermosetting resin, applying a layer of fibrous reinforcing material to a side of the impregnated foam sheet, compressing the foam sheet and reinforcing layer so that resin is expelled from the sheet into the fibrous reinforcing layer thus impregnating this layer with resin throughout its thickness, and allowing the resin in the sheet and layer to cure whilst maintaining the compression.
In accordance with the present invention, the compression of the assembly formed by the impregnated foam sheet and reinforcing layer is effected by the expansion pressure of a foaming composition. The present method has the advantage that no special compression means are required to compress the resin impregnated foam sheet, because the expansion pressure of a foaming composition is used for this purpose. Furthermore, the resulting product, which consists of a layer of foamed material formed by the foaming composition with a rigid facing formed by the compressed original foam sheet and resin-impregnated fibrous material, is particularly useful for many applications. Depending on the intended use of this product, the foaming composition can be selected so as to produce a foam which is rigid, flexible or semi-flexible.