Patent GB-654925-A (GB)
Title: Improvements in or relating to method of producing fibre-reinforced resinous parts and the product resulting therefrom
IPC: B32B27/00
Filed: 1946-05-31
Abstract: 654,925. Moulding fibre-reinforced resinous articles. STEVENS, A. H. (Marco Chemicals, Inc.). May 31, 1946, No. 16587. [Class 87 (ii)] Fibre-reinforced resinous articles, e.g. hats, are formed by introducing a fibrous base 9, Fig. 1, between complementary mould parts 10, 11 providing a mould space having an outlet 13 for air and liquid, introducing a polymerizable or condensible resinous material in liquid state into the mould space to cause it to flow through the space to impregnate the base 9 and to drive therefrom and from the mould space air contained therein, and curing or setting the impregnated base and resinous material while retained between the mould parts. The fibrous base is draped about the male part 11 and the assemblage is then placed in the female part 10, which may be provided with heating or cooling means. The resinous material is then fed under pressure to the mould space through a sprue 12 until it flows out of the peripheral space 13 or bleed holes provided for this purpose. The curing or setting may be effected under low pressure, e.g. the weight of the male part alone or an applied pressure of up to 300 pounds per square inch. As shown in Fig. 2, the assemblage of mould parts and base is placed in a tank of the resinous material and suction is applied through the pipe 18. Alternatively, instead of the tank, a tube may be connected from the male mould part to a source of resinous material which is sucked up through the tube into the mould, in which case the outlet 21 is sealed. In further modifications the closing action of the mould parts provides the force necessary to drive the material into the fabric and air therefrom. Thus, the fabric is stretched across the mouth of the female mould part which contains the resinous material and the downward movement of the male part draws the fabric into the female part and forces the resinous material to impregnate the base &c. Alternatively, the resinous material is poured directly on the fabric bridging the mouth of the female part. Laminated articles may be formed by placing a fibrous sheet into the female part, adding the resinous material, then placing a second sheet on the resinous material and moving the male part on to the materials and into the female part. The fibrous base may be already coated on one side with a resin or with a nitrocellulosic or other lacquer, and may be already impregnated with sizing, resinous materials &c. as long as it is capable of further impregnation. To provide a gloss on the outer surface of the moulded article, the mould surface may be preliminarily coated with a thermosetting resin which is partially or completely cured before the impregnation of the fibrous base. The mould surfaces may be treated with lubricants, regenerated cellulose plastic sheeting, metal foils, rubber sheeting or other liners to prevent adhesion. The moulds may be of any shape, e.g. flat, and reinforcing inserts may be introduced into the mould and formed integral with the fibrous base during the curing or setting step. The resinous materials may be compounded with various fillers, pigments, softeners, plasticizers &c, and many examples of suitable resinous materials and mixtures thereof are given in the Specification together with examples of catalysts which may be used with materials polymerizable with heat and/or light. Examples of fibrous materials used are sheets of cotton or wool fabrics, canvas, duck, muslin, linen, rayon or nylon fabrics, woven or felted glass fibre, paper, asbestos or cotton batting, sisal, macerated fabrics and combinations of these in a plurality of layers with or without added filler materials.