Elastic structural seal profiles - of cellular flexible PVC with a smooth soft solid skin using non-cellular flexible PVC or polyethylene for superficial continuity

摘要

Seal profiles for use around window frames, door frames etc. are made as extrudates with a core of expanded flexible PVC surrounded by a skin of solid elastic material at least 0.1 mm thick. The skin may be of similar material to the core, i.e. plasticised PVC(but non-cellular), or of a different material, specifically polyethylene. Pref the skin has a density =40% greater than that of the core and a thickness of =1/8th of the max cross-section of the seal profile. Pref the skin is of constant thickness, applied by co-extrucsion around the core, and opt. has a different colour to the core. The smooth, soft surface ensures a better interfacial seal with the adjacent structures than use of profiles with rigid surfaces or rough, cellular or dimpled surfaces. PVC used may be plasticised externally (by additives) or internally (by copolymerisation).