New Products # 1995 Edinburgh
PVC products have suffered in the last years from attack by environmental activists. The production of PVC with its chlorine based raw material and the incineration of PVC with the suggested emission of dioxine have been used as arguments to try to curtail the use of PVC in all application areas. The PVC pipe manufacturers in Holland, united in the FKS (The Federation of Manufacturers of Plastic Piping Systems), decided in 1990 to address this problem and to show that the use of PVC in piping systems is a justifiable activity, in particular, when considering environmental issues. The first action was to avoid the possibility that used pipes and fittings coming from the demolition of buildiigs or renovation projects should find their way to waste dumps or incineration plants. Therefore, a system has been devised to collect this pipe and fitting waste and deliver it to the members of the FKS. Special techniques have been developed to provide sorted, cleaned and ground raw material suitable for the extrusion of a pipe product of acceptable quality. The coextrusion of non-pressure sewage pipe, already developed in the 1980's and introduced into the Dutch market in 1987, has provided the outlet for this waste. The coextruded pipe, up to 4500 mm,has the external compact layers in virgin PVC material whilst the intermediate layer consists of scrap material regenerated from the collected waste. This intermediate layer can be compact or foamed depending upon the application of the sewage pipe. These pipes meet national standards and international standards are being drafted. Liie cycie analysis has shown that this coextruded pipe, contrary to pp'rila : opinioc, is es environmentally friendly as the traditional concrete and clay sewage pipes.