Abstract: A polymer material of the fluorine-containing polyurethane acrylate type for coating an optical fiber or for an optical fiber tape, the material being based on at least a diol, a diisocyanate, and an acrylate, and being characterized by the fact that at least one of the above compounds contains fluorine and that at least one of the above compounds contains sulfur.

Abstract: A multi-waveguide cylindrical optical conductor for telecommunications cable, the conductor comprising a plurality of optical fibers, each of which is a unit cylindrical fiber constituted by a core and by cladding, the unit fibers are all connected together by silica after a fiber-drawing operation, wherein said core of said unit cylindrical fiber has a diameter of about 8 .mu.m to 10 .mu.m, wherein said cladding has an outside diameter lying in the range 25 .mu.m to 35 .mu.m, and wherein all of the cores of said unit fibers are either situated regularly on generator lines of a cylinder having the same axis as said conductor, or else are parallel with one another and are coplanar. An optical conductor can thus be obtained having an outside diameter of 125 .mu.m and containing six waveguides each having a diameter of about 25 .mu.m to 35 .mu.m.

Abstract: The present invention relates to the preparation of an optical fiber in a form suitable for use in the manufacturing of a telecommunications cable having one or several fibers. The fiber is reinforced by a longitudinally disposed support element intended to bear at least a part of any traction forces which would otherwise be borne by the fiber.

Abstract: The present invention relates to optical fibres with a protective covering for use in cables. The fibre is protected by a covering of plastic material extruded from an extruder the punch of which protrudes 0.5 to 1 mm beyond the draw plate, and rapidly cooled at the outlet of the draw plate, so that it surrounds the optical fibre with a clearance between 1 and 10 microns.

Abstract: A method of extruding a cross-linked material, more particularly an insulating cross-linked material around an electrical cable. In an extrusion machine comprising a housing terminated with an extrusion head and provided with a filtering means adjacent the outlet end of said housing, the cross-linkable product is fed without addition of a cross-linking agent, said cross-linking agent being first introduced in said cross-linkable material downstream said filtering means. The cross-linkable material is kept in the housing at an elevated temperature to be in a fluid state, the cross-linking agent being introduced at a temperature slightly lower than its reaction temperature, whereby the extrudate may be at a temperature near the maximum temperature admissible for the extrusion of said material.

Abstract: A method of extruding a cross-linked material, more particularly an insulating cross-linked material around an electrical cable. In an extrusion machine comprising a housing terminated with an extrusion head and provided with a filtering means adjacent the outlet end of said housing, the cross-linkable product is fed without addition of a cross-linking agent, said cross-linking agent being first introduced in said cross-linkable material downstream said filtering means. The cross-linkable material is kept in the housing at an elevated temperature to be in a fluid state, the cross-linking agent being introduced at a temperature slightly lower than its reaction temperature, whereby the extrudate may be at a temperature near the maximum temperature admissible for the extrusion of said material.

Abstract: Coating for optical fibres comprising at least one layer of a resinous composition which hardens in the cold and in a few seconds upon contact with a gaseous catalyst applicable more particularly to optical fibres intended to be assembled together in a cable.