Prefabricated cellular insulating element of phenolic foam - with outer protective layer of paper and aluminium foil

摘要

Prefabricated heat and sound insulating laminated element e.g. for pipes, comprises a low density phenolic foam core, a high density skin and a surface layer of fire-retardant paper bonded to Al foil. A 2 - 15 um thick coat of varnish, e.g. vinyl chloride/vinyl acetate copolymer, may be applied to the Al foil and between the upper and the foil. The element may be made by conforming a preformed paper/Al foil laminate to the mould surface, injecting the phenolic resin, placing a layer of fire-retardant paper on the upper part of the mould, foaming and curing. The Al surface is moisture- and vapour-impermeable. Prefabrication avoids the need for special treatment after installation.