Patent GB-545716-A (GB)
Title: Process for improving the tensile strength of cotton yarns and cords such as tyre cords
IPC: B29D30/40
Filed: 1941-02-03
Abstract: 545,716. Treating textiles with liquids ; proofing permeable materials ; coating webs. UNITED STATES RUBBER CO. Feb. 3, 1941, No. 1376. Convention date, Feb. 17, 1940. [Class 15 (ii)] [Also in Group VIII] Cotton yarns or cords are given improved tensile strength by treating them, while they still contain the natural waxes and similar constituents of the raw cotton, with a watersoluble wax-emulsifying compound and permitting the resulting wax compound to remain on the cotton. The treated yarns or cords are in general subjected to stretching to an extent just short of breaking point so as to increase the tensile strength still more. The process is applicable to the preparation of cotton tyre cords. The waxy materials present in raw cotton comprise sterols, glycerides, waxes, fatty acids, higher paraffin hydrocarbons and alcohols. The cords may be impregnated with rubber latex at the same time as the treatment with emulsifying agent. A number of cords may be agglutinated by the rubber latex so as to form a fabric. The cotton yarn or cord may be dipped in an aqueous solution of the emulsifying agent or it may be sprayed. The emulsifying agent may be an alkali metal salt of an alkylated aromatic or hydroaromatic compound containing a functional acidic group rendering it soluble in aqueous alkali.. It may be a salt of an alkylated aromatic or hydroaromatic carboxylic or sulphonic acid or phenol. It may be a sodium salt of the mixed resin acids and phenols occurring in commercial rosin or colophony, or it may be sodium abietate, an alkylated diphenyl-, hydroxy-, diphenyl-, or chloro-diphenyl sodium sulphonate, or a tetrahydro-naphthalene sodium sulphonate, a hydrogenated sodium abietate, abietene sodium sulphonate, or an alkylated naphthalene sodium sulphonate. Sodium silicate may be used with a penetrant. Mixtures of sodium rosinate with sodium silicate or phosphate may be used. In examples, there are used rosin with sodium hydroxide, rosin with sodium silicate, and sodium silicate with a sodium alkyl naphthalene sulphonate. Instead of sodium rosinate other alkali metal salts of rosin may be used. As shown in Fig. 1, cords 1 arranged in parallel manner, pass over roller 2, under roller 3, and over roller 7 into a trough 5 containing the treating liquid 4. Roller 6 causes the cords to dip into the liquid 4 which may be an aqueous solution of sodium rosinate. Surplus liquid is removed by passing the cords over the slotted pipe 9 connected to suction. The cords then pass into a bath of latex in the tank 14. They pass under immersed roller 15 and then over drying roller 16. The fabric so formed is wound on roller 18. As shown in Fig. 2, the cords 19 pass round roller 23 immersed in a solution of emulsifying agent, between squeeze rolls 24, 25, and then to the stretching rolls 26-28, and 29-31. A positioning roller 34 and squeeze rolls 32, 33, are placed between the stretching rolls. Excess of treating liquid still on the cords is removed by the water sprays 38, 39. The cords then pass through a bath of latex in tank 44 and then through a drying chamber. They may be wound up at the same speed as that of the second set of stretching rolls or at a lower speed in order that all or part of the original elongation may be removed by shrinkage.