| 摘要 |
Disclosed is an automotive fuel conduit which comprise an inner tube, an outer tube substantially surrounding the inner tube and mechanical locking structure at the interface between the outer surface of the inner tube and the inner surface of the outer tube for preventing substantial relative movement between the inner and outer tubes. The mechanical locking structure preferably comprises a plurality of mating projections and indentations on the inner surface of the outer tube and the outer surface of the inner tube, such as grooves, cuts and ridges. The inner and outer tubes are preferably each formed of polymeric material and each contain both projections and indentations. Methods are also disclosed which comprise providing a first polymeric tubular product having projections and/or indentations in at least a portion of the external surface thereof and melt extruding over said first tubular product a second polymeric tubular product such that the polymeric material of said second tubular product flows into said indentations and/or around said projections during the extrusion process. |
