Patent GB-535140-A (GB)
Title: Manufacture of artificial wool
IPC: D02G1/12
Filed: 1939-09-12
Abstract: 535,140. Crimping fibres ; resinous condensation products. DU PONT DE NEMOURS & CO., E. I. Sept. 28, 1939. No. 26815. Convention date, Sept. 29, 1938. [Classes 2 (iii) and 15 (ii)] Fibres of synthetic linear polymers are carded and compressed into bales and the compressed fibres are subjected to a setting treatment in order to produce a crimped wool-like product. The setting treatment may be a, dry heat treatment or a treatment with a mild swelling agent, e.g. steam, hot water, methanol or ethanol liquid or vapour, at atmospheric or elevated pressure. The mild swelling agent is preferably an hydroxyl compound. The treatment may be carried out on fibres obtained from filaments which have been subjected to a cold drawing process. Synthetic linear polymers specified are polyamides such as those from monoaminocarboxylic acids or their amide forming derivatives including caprolactam, and those from diamine-dibasic acid mixtures or their equivalents. After treatment with the setting agent the fibres are unpacked from the bales and again carded. The crimp produced is stable to tension, friction, and water or steam at 100C. or higher temperature. In examples, fibres of polyhexamethylene adipamide are carded, compressed tightly into a small bale, treated with steam, methanol vapour, or ethanol vapour under pressure, dried, and re-carded. In another example, a bale of tightly packed fibres of polydecamethylene adipamide is treated with acetone vapour under pressure. Fibres made of synthetic linear polymers modified by incorporation of plasticizers, resins, oils, cellulose derivatives, dyes, or pigments, may be treated. Polyamides obtained from tetramethylene adipamide, suberamide, or sebacamide, pentamethylene sebacamide, hexamethylene adipamide or sebacamide, octamethylene adipamide, decamethylene adipamide or p-phenylene diacetamide, and p-xylylene sebacamide are specified polyamides from diamines and dicarboxylic acids. Polymers from 7-aminoheptoic acid, 9-amino nonanoic acid, and 11- amino undecanoic acid may be used. Fibres from interpolymers of a mixture of polyamide reactants, e.g. two diamines with one or more dicarboxylic acids, or a mixture of a diamine dicarboxylic acid and an amino acid, or fibres from polyesters, polyacetals, or interpolymers with polyamides may be used. The fibres may be mixed with cellulose acetate or viscose rayon fibres. The polyamides may be derived from esters, acid halides, anhydrides, amides, or lactams, of monoamino monocarboxylic acids, or from monoamino mononitriles, or from diamines and dinitriles, diisocyanates. diisothiocyanates, diurethanes, dithiodiurethanes, or tetrathiodiurethanes. The setting treatment of the compressed fibres may be effected with water, ethanol, methanol, isobutanol, propanol, acetone, methyl ethyl ketone, dibutyl ether, amyl alcohol, or toluene, at 100-150C, or higher, or with hot aqueous solutions of phenol, formic acid, ethylene glycol, acetamide, hydrogen chloride, or sodium chloride. The process may be carried out continuously by leading the carded fibres into a compressing device enclosed in the setting chamber and pushing them out continuously on the other side of the chamber as crimped staple yarn. Specifications 461,236 and 514,821 are referred to.