| 摘要 |
<p>Roofing panels are made by moulding and mating of complementary shells of fibre-reinforced resin to produce hollow panels which can be supported and assembled in rows to cover a roof. At least one face of the hollow panel is profiled, i.e. by undulation, to enhance the stiffness. The shells are laid up in pairs of moulds, which are exposed to heaters to precure the faces prior to mating and curing the rims of pairs of shells before the resin in the rim zones has set. Pref. panel shells are made of a phenol (resole/aldehyde resin reacted with a glycol (12-35% wt. in resole content) using acid catalysts. The fibres are pref. mineral, specifically of glass and/or asbestos. The moulding composition may incorporate a powdered filler. The exposed face may be covered with a weather-resistant gel coat, opt. polyester resin based. The panels are lighter and provide better thermal insulation than conventional concrete or brick tiles. The materials used are less flammable than e.g. PVC, or acrylic resin based profiles.</p> |
