| 摘要 |
A method for the production of a plastics pipe ( 9 ) comprising an inner core and an outer removable skin bonded thereto, which method comprises co-extruding molten polymeric materials forming the inner core and the outer removable skin layer from one or more extruder dies, bringing the polymeric materials together and allowing them to solidify, and conditioning the solidified polymeric materials at a temperature and for a time sufficient to influence the adhesion of the outer skin layer to the inner core, such that on cooling the adhesion of the outer skin layer to the inner core is sufficient to prevent substantial undesired relative movement between the skin layer and the core during installation of the pipe (9), but insufficient to prevent the outer skin layer from being clearly removed by peeling, at least at the ends of the pipe ( 9 ), and insufficient to cause a substantial reduction in the impact strength of the inner core.
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