MULTI-LAYER TUBING HAVING AT LEAST ONE INTERMEDIATE LAYER FORMED FROM A POLYAMIDE/POLYKETONE ALLOY

摘要

A multi-layer tube (10) suitable for use in motor vehicle system to transport fluids containing hydrocarbons such as would be found in a fuel line, a vapor return line or a vapor recovery tube having a first layer (14) radially disposed innermost made up of an extrudable melt-processible thermoplastic material selected from the group consisting of aromatic polyketones, aliphatic polyketones and mixtures thereof, and second layer (16) made up of an extrudable, melt-processible thermoplastic material capable of sufficiently permanent laminar adhesion with the first layer so as to prevent delamination between the first and second layers during a desired lifetime of the tube, and a third layer (12) overlying the first layer made up of a melt-processible thermoplastic material such as polyamides, high density polyethylenes and mixtures thereof. The tubing of the present invention may, optionally, include additional layers interposed between the respective layers or may include additional layers which overlie the exterior surface of the second layer.