| abstract |
The use is described of rigid foam cores in panels, especially doors, of the kind comprising a foam core ( 22 ) between two molded skins ( 8,10 ). The weather-resistance, especially the resistance to thermally-induced bowing, of such panels is improved by forming the panel of at least one vacuum-formed thermoplastics skin ( 8,10 ) adhesively bonded to a substantially open-cell, rigid foam core ( 22 ). If the foam has frangible cell walls, it can be conformed to accommodate the depressed zones of a molded overlying door skin ( 8,10 ) by crumbling under compression, with fracture of the cell walls to accommodate the zones. A preferred open-cell rigid foam is a phenolic foam reinforced with finely divided particulate filler. |