| 摘要 |
A plastics pipe which comprises an inner core and an outer protective layer, in which the dimensions of the pipe and the protective layer are such that the ratio of the external diameter of the pipe to the thickness of the protective layer is at least 70, preferably at least 100, and the cohesive strength of the outer protective layer, excluding any lines of weakness, at least at the ends of the pipe is greater than the strength of the adhesive bond between the outer protective layer and the inner core. |
