Abstract: Provided is an optical fiber cable that is easier to be laid and enables higher-density packaging than an existing cable. This optical fiber cable is a slotless type optical fiber cable including: an optical unit formed by collecting and twisting a plurality of optical fibers or ribbons each formed by arranging the plurality of optical fibers; a cable core housing the optical unit; and a cable jacket provided around the cable core, and a tension member made of a fiber body within the cable core.

Abstract: Provided is a polyethylene resin for use in a spacer for an optical fiber cable, the polyethylene resin having a density of 0.952 g/cm3 or more, containing a polyethylene having a molecular weight of 10,000 or less in a weight fraction of 22% or more, and containing a polyethylene having a molecular weight of 300,000 or more in a weight fraction of 12% or more.

Abstract: Provided is a polyethylene resin for use in a spacer for an optical fiber cable, the polyethylene resin having a density of 0.952 g/cm3 or more, containing a polyethylene having a molecular weight of 10,000 or less in a weight fraction of 22% or more, and containing a polyethylene having a molecular weight of 300,000 or more in a weight fraction of 12% or more.

Abstract: An optical fiber cable includes: optical fiber units obtained by collecting a plurality of optical fiber ribbons in which a plurality of optical fibers are arranged in parallel; and a slot rod including a plurality of slot grooves formed in a spiral shape in order to store the optical fiber units. The optical fiber units are stranded in a longitudinal direction of the optical fiber cable in a state in which the optical fiber ribbons are not twisted, and the optical fiber units are stored in the longitudinal direction of the optical fiber cable in a state of being untwisted stranding in the slot grooves.

Abstract: Provided is an optical fiber cable that is easier to be laid and enables higher-density packaging than an existing cable. This optical fiber cable is a slotless type optical fiber cable including: an optical unit formed by collecting and twisting a plurality of optical fibers or ribbons each formed by arranging the plurality of optical fibers; a cable core housing the optical unit; and a cable jacket provided around the cable core, and a tension member made of a fiber body within the cable core.

Abstract: A method of producing a synthetic resin rod (wire), comprising: an extruding step of extruding a synthetic resin rod; a pre-cooling step of spraying a cooling medium on the rod to pre-cool the rod extruded down to a temperature (T° C.) satisfying the following condition: T?{(a softening point of the synthetic resin)+5} [° C.]; and a main cooling step of letting the rod thus pre-cooled pass through water to cool the rod.

Abstract: In a method of making a ribbon type coated optical fiber 3 comprising the step of inserting a plurality of optical fibers 1 flatly arranged parallel to each other through a die orifice 11a so as to collectively coat the optical fibers with a coating resin 2, the ratio W/H of a clearance W in the width direction between the inner surface of the die orifice 11a and the outer surface of the optical fibers 1 to a clearance H in the thickness direction therebetween is set within the range of 1.0 to 2.5.

Abstract: In a split type ribbon optical fiber core cable capable of being split into cables, there are a plurality of ribbon optical fiber core cable units, each of which are constituted by a plurality of colored optical fiber core cables arranged in a row; a coating resin of an ultraviolet curable resin wholly coats the plurality of colored optical fiber core cables; and a bonding resin of an ultraviolet curable resin bonds the ribbon optical fiber core cable units arranged in a row. In this cable, an adhesion strength between the coating resin and the bonding resin is in the range of 1 to 100 g/cm. Further, the bonding resin after curing has a Young's modulus of from 5 to 100 kg/mm.sup.2. The bonding resin after curing has an elongation coefficient of from 5 to 80%.

Abstract: An optical fiber ribbon is manufactured under a condition where, assuming that the optical fiber ribbon has a thickness of 2d (mm), a guide roller has a diameter of 2R (mm), and a period of time till the optical fiber ribbon comes into contact with the guide roller after leaving an ultraviolet irradiation apparatus is t (ms), a relationship of d/?(R+d).times.t!<0.2 is satisfied. Accordingly, no damages are imparted to the optical fiber ribbon, and no micro-bendings occur in its coated optical fibers, whereby the transmission characteristic can be prevented from deteriorating.

Abstract: In a method for producing an optical fiber ribbon, a plurality of coated optical fibers is fed out so that the plurality of coated optical fibers are arranged in a plane in a concentrator. A ribbon matrix composed of ultraviolet-curing resin is applied onto the plurality of coated optical fibers in a coater. Ultraviolet rays is radiated to cure the ribbon matrix. The plurality of coated optical fibers are arranged at intervals in a plane in the concentrator.