摘要 |
<p>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 the cloth ( 4 ) to the body ( 2 ) and to an outer aluminium foil ( 5 ). The glass sheet ( 3 ) may be a mirror, and may be replaced by a glass laminate ( 20;23 ) that includes a fused-powder coating ( 22;25 ) with or without an aluminium foil backing.</p> |