| 摘要 |
An improved elongate deformable tube for use in the conveyance of fluids and/or fluid transmission signals under pressure having a bore therethrough enclosed by a composite annular wall comprising a seamless, as welded, or welded and drawn inner tubular shaped layer made from a metallic material and an outer tubular shaped layer made from a polymeric material. The walls of both the inner and outer layers are substantially uniform in radial thickness around their circumferences with the radial wall thickness of the outer polymeric layer being 50% or more than the total radial thickness of the composite wall of the tube. The outer layer is preferably formed about the inner layer by means of an extrusion process. The inner and outer layers are bonded together by means of a polyamide based hot melt adhesive interposed therebetween which preferably contains an amount by weight of piperazine used in the process of making the polyamide which is less than about 15% by weight to the total weight of the polyamide and that is sufficient to enhance the bond between the layers without adversely affecting its resistance to water degradation. The outer diameter of the outer layer is sized, during the process of making the tube, such that the tube can be attached, without further dimensional alteration, to fittings standardly used to couple equivalently dimensioned tubes having a singular polymeric or metallic wall. |
