Improvements in and relating to the manufacture of strengthened fibrous cord and thelike

摘要

600,424. Cords; catgut substitutes. TELEGRAPH CONSTRUCTION & MAINTENANCE CO., Ltd., DEAN, J. N., DUNLOP RUBBER CO., Ltd., and VAUGHAN, G. Oct. 5, 1945, No. 26035. Drawings to Specification. [Class 109] Strengthened fibrous cord, particularly catgut substitute, comprises strands of fibrous material of natural or artificial origin individually coated with a thermoplastic material comprising mainly polythene. The cord may additionally have an outer coating of the thermoplastic material. The polythene may be pure or admixed with up to 10 per cent of a diluent such as polyisobutylene, paraffin wax, or chlorinated naphthalene such as that known under the Registered Trade Mark " Halowax." The fibres specified comprise silk, rayon, nylon, manilla and glass. In one method of manufacture, the separate strands are passed through an extrusion machine where they are impregnated and coated with the thermoplastic material, then through a cooling tank and a trimming die to the haul-off drum ; they are finally reheated by passage through a furnace chamber before twisting to a composite cord in a twisting machine. Alternatively, the! separate strands are passed through a bath of the heated thermoplastic material and then immediately through the trimming die on to the haul-off drum, which is simultaneously rotated on an axis at right angles to the axis of the winding rotation, so as to twist the strands to a composite cord whilst still hot. To impart a smooth surface and a circular cross-section to the cord, the latter is again passed through the bath of thermoplastic material, trimming due and finally to the haul-off drum spaced at a distance to allow of cooling and hardening of the thermoplastic material. The fibrous material, the thermoplastic and the finished coated material may all be subjected to vacuum treatment to remove air, moisture and other volatiles. Specification 581,496 is referred to.