MULTI-LAYERED FUEL TUBING

摘要

The invention describes a flexible tubular article for transport of volatile hydrocarbons comprising: (a) an inner layer of a polyvinylidene difluoride (PVDF) polymer or a polyvinylidene difluoride copolymer; (b) an intermediate thermoplastic polyurethane (TPU) layer extruded in tubular form over the inner PVDF layer, and (c) a polyvinyl chloride polymer extruded in tubular form over the outside surface of the intermediate layer and being coextensive therewith. The tubular articles of the invention have a maximum permeation rating of 15 g/m2/day under SAE J1737 test conditions.