MULTI-LAYER TUBING ASSEMBLY FOR FLUID AND VAPOR HANDLING SYSTEMS BUNDY CORPORATION

摘要

PURPOSE: A coextruded multi-layer tubing assembly is provided which has an inner fluoroplastic permeation resistant layer, a middle adhesive layer, and a non-vulcanized rubber-like multiphase polymer cover layer. CONSTITUTION: A tubing assembly includes an extruded innermost semi-conductive fluoroplastic layer. The fluoroplastic is made semi-conductive by mixing it with 1% to 10% by weight of conductive carbon black. Metallic conductive fillers such as silver, copper or steel are utilized. The tubing assembly has a surface resistivity in the range of about 10 to 1000000 ohm/sq, with a preferential range of 100 to 100000 ohm/sq. Herein, Suitable fluoroplastics include ETFE(ethylene tetrafluoroethylene), THV(a terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride), PVDF(polyvinylidene fluoride) or blends of these fluoroplastics. An inner permeation-resistant fluoroplastic layer coextrudable at temperatures below 600 degrees Fahrenheit is coextruded with and surrounds the innermost semi-conductive layer.