Glass fibre reinforced polymer roofing sheets - made by applying resin-filler mixt. to both sides of glass fibre web, pressing between film support and curing

摘要

Sheets are made by (1) applying a layer of a mixt. of a filler and a synthetic resin to a lower covering film on a moving convertor; (2) applying a glass fibre reinforcement; (3) applying a further layer of the resin/filler mixt; (4) applying an upper covering layer of the film; (5) compressing the resulting laminate e.g. by rolling to remove occluded air and (6) polymerising or polycondensing the synthetic resin to form an opt. profiled sheet material. The resin/filler mixt. is esp. of a phenolic resin in an amt. of 75-85%, esp. 77.83%, and aluminium silicate filler in an amt. of 4-8%, 7.78%, together with 2-5, esp. 2.33% colourant, 3-4% water and 6-10% p-toluenesulphonic acid catalyst. The upper layer of resin/filler mixt. and top covering foil may be applied together. Pref. after the glass fibre reinforcing layer has been applied to the lower resin/filler layer, the web is drawn flat over a perforated suction plate to that the resin/filler mixt. distributes uniformly over the web. After the laminate is complete, it passes through a heat treatment zone e.g. contg. infra red heaters to cure the resin. The process gives prods. avoiding occlusion of air in the lower layer. Prods. are esp. useful as replacements for asbestos-cement roofing and siding sheets, and are cheaper than polyester/glass sheets which have a high content of relatively expensive polyester resin.