Patent GB-1484270-A (GB)
Title: Process of and apparatus for the manufacture of cordage and ropes and the cordage and ropes produced thereby
IPC: D07B1/02
Filed: 1974-07-31
Abstract: 1484270 Fibre ropes; braids CORDES EUROPE-FRANCE 31 July 1974 [1 Aug 1973 26 June 1974] 33748/74 Headings D1K and D1T A process for making fibre ropes comprises braiding or stranding a plurality of strands of aromatic polyamid fibres together, the strands of the rope being impregnated with either an aqueous dispersion of a fluorcarbon resin or a solution of urethane polyesters and aromatic isocyanates, the rope being heated to remove moisture therefrom and tensioned. When the impregnation is with a flourocarbon resin, a non-ionic wetting agent may be added during said impregnation to facilitate penetration. Such a rope, after it has been dried by heating, can be provided with a sheath for example a sheath of the same agent as that used for the impregnation. The following impregnating mixture may be used the proportion being by weight. 100 parts of pre polymerized long-chain urethane polyester; 12 parts ,of polyfunctional aromatic isocyanate serving as an adhesive on the filaments;  1.6 parts of an organic nitrogen derivative, combined with a metallic compound, acting as an accelerator and as an anti-cryptogamic agent; and  1 part of polyurethane wax, for preventing the turns of rope sticking together when wound on the final drum. Modifications may be made in the above proportions for the purpose of greater suppleness; greater adhesion or for varying the polymerization period. The mixture confers the following qualities to the rope: elasticity, abrasion resistance, resistance to tearing, resistance to ageing under the action of oxygen and ozone, resistance to severe climatic conditions and high stability to organic solvents, fatty materials and oils. The components may be disolved in a solvent such as ethyl acetate. The following concentrations may be selected in ethyl acetate: 1) a 10 to 15% solution of prepolymerized urethane polyester; 2) a maximum of a 75% solution for the crosslinking agent; 3) a maximum of a 10% solution for the accelerator; 4) a solution of fluidity identical to 2 and 3 above of the polyurethane wax.  Colouring matter may be added to enable the ropes to be marked for to improve the appearance thereof. The impregnated stranded rope is then dried, for example by passing it through an oven in which its temperature is progressively raised, for example from 60 to 110‹C, to prevent the formation of blisters. On leaving the oven the rope is passed through a solution that will ensure a uniform and adhesive bonding with the sheath to be formed in the succeeding operation, for example:- 20 to 30% of prepolymerized urethane polyester. 75% of the cross-linking agent. 10% of the accelerator. The cable is then sheathed, for example by extruding a polyurethane elastomer around the rope. Alternatively, to guard against possible porosity the rope may be passed through a low-viscosity bath of electrically insulating silicone oil. The strands of the rope may be separated into groups by means of impermeable tapes, such as tapes of polvurethane. In Fig. 2 a core 20 has a tape 21 applied to it. The taped core then passes through a yarn stranding machine 24 from which it emerges as a stranded rope 25.