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 thermoplastic polyurethane (TPU); (b) an intermediate polyvinylidene difluoride (PVDF) polymer or PVDF copolymer layer extruded in tubular form over the inner TPU layer, and (c) a TPU extruded in tubular form over the outside surface of the intermediate layer and being coextensive therewith. Optionally, a fourth outer layer is included and covers layer (c). The tubular articles of the invention have a maximum permeation rating of 15 g/m2/day under SAE J1737 test conditions.