Plastic body prepn. with protective sleeve for electric or optic fibre cable - comprises extruding body with thermally shrinkable plastic layer while simultaneously extruding with tensile strength elements to embed them into layer, giving high strength and resistance

摘要

Prepn. comprises extruding body with a thermally shrinkable plastics layer (KS1) while simultaneously extruding the elements (ZE11, ZEn) for tensile strength with the layer (KS1) for them to be embedded. Polymer materials are used for the plastics layer (KS1) and the tensile elements (ZE11, ZEn) which, after extrusion bond together. Identical or similar polymers are pref. used for the plastics layer (KS1) and the tensile elements (ZE11,ZEn). During or after extrusion, the plastics layer (KS1) material is crosslinked followed by orientation across the longitudinal axes of the tensile elements (ZE11,ZEn) while hot. During cooling, the material is not allowed to return to its original condition. Polyolefins and polyolefin blends, which can be crosslinked, are pref. used for the plastics layer (KS1), together with a previously added radical creator or other additive before extrusion, to give or strengthen crosslinking. The crosslinking is effected at least partially by the extrusion heat, followed by further heating. A silane crosslinking reaction can be used or the material can be irradiated by energy radiation for crosslinking. The material for the tensile elements (ZE11,ZEn) contains additives for a stronger crosslinking than in the material for the plastics layer (KS1), usng partially crystalline polymer with crystallite m.pts., or amorphous polymer with a softening temp. above the softening or m.pt. of the plastics layer (KS1). USE/ADVANTAGE - The extruded material is a flat plastics film, tube or hose which, when crosslinked and oriented, forms a protective sleeve, a cable coupling or a protective sleeve or outer mantle for an electrical or optic fibre cable. The plastics body is esp. strong and resistant.