
Foaming of a resinous backing (2) to a glass sheet (1) is frustrated at the interface (3) with the glass by maintaining the glass sheet (1) cool during formation of the foam. The degree of foaming is nil at the interface (3) to effect a strong bond there, and increases progressively through the thickness of the foam body (2) away from the interface (3). The foam body (2) is backed by glass-fibre cloth (4) that is impregnated with the resin from which the foaming gas has been vented so as to bond...











