GB389823A - Improvements in the treatment of artificial filaments and like products - Google Patents

Abstract

Artificial filaments, threads, yarns, and like materials containing organic derivatives of cellulose particularly materials of low extensibility obtained by wet spinning or by dry spinning with stretching, are treated with organic solvents, latent solvents, or swelling agents, in the absence of tension sufficient to stretch them, and preferably they are allowed to shrink, whereby the extensibility is increased with little or no loss of tenacity. Treatment with shrinking agent is carried out in the absence of or with low tension. If higher tension is employed, it is subsequently decreased or removed to allow the material to shrink. The shrinking agent may be acetic, formic, or lactic acid, acetone, diacetone-alcohol, mono- or dimethyl or ethyl ether of ethylene glycol, glycol monoacetate, methyl glycol mono-acetate, dioxane, ethers of propylene glycol, ethers of diethylene glycol, phenols, acetins, dichlorethylene, ethyl lactate, or diethyl tartrate. Latent solvents such as chloroform, methylene chloride, ethylene chloride, tetrachlorethane, or ethyl acetate may be used in the case of acetone-soluble cellulose acetate. The shrinking agent may be diluted with water, glycol, glycerol, benzene, toluene, xylene, benzine, petrol, kerosene, carbontetrachloride, trichlorethylene, perchlorethylene, tetrahydronaphthalene, or decahydronaphthalene. The shrinking agent is applied in the form of vapour, or by spraying, dipping, or padding methods. The yarns may be treated loose, in hanks, on bobbins, on swifts, in cakes or in other package form. By providing resilient bobbins, shrinkage may be allowed while the yarn is in package form, or it may be wound off, allowed to shrink, and rewound at a slower winding speed. If the yarn is wound loosely, shrinkage may take place even on non-resilient bobbins. The process may be carried out continuously with wet spinning, or dry spinning with stretching and the softening agent remaining on the filaments after the stretching operation may be utilized as the shrinking agent. The process may be applied to yarns in warp formation. If desired the yarn may be dried without washing out the shrinking agent. Specifications 177,868, 179,234, 277,089, 323,790, 336,217, [all in Class 2 (ii), Cellulose &c.], 340,324, 340,325, 340,326, 340,436, 340,437, 362,939, 370,430, 371,461, 378,074, and 378,858 are referred to. The Provisional Specification also includes local treatment with the shrinking agent.