Patent ID: 8685508

Claim:
A plastics pipe which comprises an inner core and an outer removable skin layer bonded thereto, the inner core comprising polyethylene, the outer removable skin layer comprising an adherent polymeric material comprising a propylene block co-polymer, chosen for its physical and mechanical properties, and an appropriate amount of an adhesion-reducing additive, the adhesion-reducing additive being present in the skin layer in an amount such that the adhesion of the skin layer to the inner core is sufficient to prevent substantial undesired relative movement between the skin layer and the core during installation, but insufficient to prevent the outer skin layer from being cleanly removed by peeling, at least at the ends of the pipe, and insufficient to cause a substantial reduction in the impact strength of the inner core, wherein the adhesion reducing additive is an ester of glycerol with erucic acid, stearic acid, lauric acid, linoleic acid, myristic acid, oleic acid, palmitic acid, ricinoleic acid or behenic acid, or a fatty acid amide selected from oleamide, stearamide, erucamide, behemamide and ethylene-bis-stearamide wherein the adhesion-reducing additive in the skin layer is present in an amount of from 0.5% to 10% by weight; and the skin layer has a thickness of from 0.3 to 2.0 mm such that the adhesive bond between the skin layer and the inner core having a strength of from 0.2 N/mm to 2.0 N/mm, when measured by a rolling drum peel test as described in Appendix 1.