Composite foam roof insulation

摘要

A heat-insulating sandwich-like composite comprising a core of foamed resin based compound sandwiched between and adhering to single face corrugated board with a high wet strength. The single face corrugated board is perforated prior to foaming of the resin based compound so as to allow the excess of volatile matter to escape and some foaming mixture to penetrate inside the corrugated flute. The composite board further is provided with post-perforations made after foaming the resin compound between the corrugated board skins.