Patent ID: 6170534
Filing Date: 2001-01-09
Classification: B32B,F16L

Abstract:
A layered tubing for use in a motor vehicle, the tubing comprising:an outer layer having an inner and an outer face, the outer layer consisting essentially of an extrudable thermoplastic;an intermediate layer uniformly connected with the inner face of the outer layer in underlying relation to the inner face, the intermediate layer consisting essentially of an extrudable melt processible thermoplastic capable of sufficiently permanent laminar connection with the inner face of the outer layer, wherein the thermoplastic material employed in the intermediate layer exhibits at least some resistance to interaction with short-chain hydrocarbon molecules present in material conveyed through the tubing; andan inner layer uniformly connected with the intermediate layer, the inner layer consisting of an extrudable, melt-processible thermoplastic capable of sufficiently permanent laminar connection with the intermediate layer, the thermoplastic containing as a major constituent a fluoroplastic selected from the group consisting of polyvinylidine fluoride, polyvinyl fluoride, and mixtures thereof; andwherein the resulting layered tubing has hydrocarbon permeation level below 0.5 g/m.sup.2 per 24 hour period.