GB465875A - Improvements in or relating to the finishing of textile fabrics - Google Patents

Abstract

Crease-resistant properties are imparted to textile fabrics by treating them with reinforcing substances such as synthetic resin components, starches, or proteins, subjecting the applied substances to a hardening treatment, and mechanically treating the fabrics so as to separate the individual fibres or to prevent them from becoming stuck to each other. The fabrics may be subjected to the mechanical treatment before the hardening step and in this case they should be dried in order to avoid re-sticking of the fibres. The mechanical treatment may comprise passing the fabric under and over breaker-bars, and through a cold nip on a mangle. A stentering process may be included, or the use of expanders, to give a weft-wise treatment. For small articles a manual treatment by crumpling and scrubbing together severely may have the desired effect of unsticking the fibres. Cotton, wool, silk, and artificial silk fabrics may be treated. The reinforcing substances are of an adhesive or film-forming nature and include casein, albumen, starch, modified starches, dextrines, animal glues and gelatines, vegetable gelatines such as those from seaweed, locust-bean gum, gum arabic, algin, alginates, and synthetic resin components. Hardening may be effected in many cases by treatment with formaldehyde. It may be carried out at elevated temperature preferably under increased pressure. Catalysts such as sodium bisulphate, or sodium tetraoxalate may be used. Fillers such as French chalk, alumina, gum, and dextrines may be added to the synthetic resin components. In cases where the reinforcing substance would be still hygroscopic after hardening, a quantity of a synthetic resin component may be added to counteract this property. Fabrics may be padded with a dilute aqueous solution or dispersion of the reinforcing substance, dried, and then mechanically treated to separate the fibres. They may then be exposed to the action of paraformaldehyde at raised temperature and pressure. When casein is used, it is freed from fats and dissolved in water containing a little ammonia, the solution then being neutralized with tartaric or acetic acid, or the casein may be brought into solution with acetic acid. For the hardening step, paraformaldehyde powder may be dusted on the fabrics prior to their entry into the pressure chamber, or the powder may be volatilized in the chamber, or a dispersion of the paraformaldehyde may be padded on to a back-cloth which is dried at low temperature, then rolled up with the fabric to be treated and placed in a heating-chamber. If desired, the fabrics may be sprayed with formalin solution and then placed in the heating-chamber. Acid salts, tartaric, acetic, or oxalic acid may be present as accelerators. Paraformaldehyde dispersion may be directly padded on to the fabrics. In an example, dyed mercerized voile is padded with a solution containing casein, formalin, bisulphate, soap and sodium chlorate. It is then dried and subjected to mechanical treatment. Before drying it may be steeped in copper sulphate or acetic acid solution. Dyed voile is treated with pearl starch solution, dried, mechanically treated, and hardened with paraformaldehyde vapour. Woven fabric is treated with a solution of egg albumen, water, formalin, and potassium tetroxalate, or with a solution of skin glue, Irish moss extract, algin extract, gum arabic or locust bean extract, followed by drying, loosening, and hardening. Woven fabric with cellulose acetate warp and viscose cr<\>zepe weft is treated with a solution containing casein, water, a syrup of urea, thio-urea, and an aldehyde, and potassium tetroxalate. Resorcin and lime, or phthalic acid resins may be used instead of the urea-aldehyde. Instead of casein there may be used skin glue, locust-bean gum, or agar-agar. Viscose fabric is treated with sago starch, and urea, thio-urea, and aldehyde syrup, if desired with additional amounts of formaldehyde, tartaric acid, and alginate of alumina. Woven fabric is treated with urea, thio-urea, and aldehyde syrup, dissolved in water and containing potassium tetroxalate. Woven fabric containing cellulose acetate warp and viscose weft is treated with urea or thio-urea, formalin, and tetroxalate, or with urea-aldehyde syrup, locust - bean gum, chalk, formalin, and tetroxalate. Aluminium acetate may also be present. Woven fabric is treated with urea-aldehyde resin syrup, sago starch, alum, sodium acetate, tartaric acid, formalin, and water. Colloidal china clay may also be present. The fabric is dried, subjected to the mechanical treatment, and heated to effect hardening. Specification 452,766 is referred to.