GB727660A - A process for improving the felting shrinkage resistance of wool or wool-containing textile materials - Google Patents

Abstract

The felting-shrinkage resistance of textile material made of or containing wool is increased by introducing into the material an aminoplastic resin from an acidic aqueous true solution of resin-forming components and/or an intermediate hydrophilic condensation product thereof at a temperature from about 80 DEG C. to the boiling temperature of the solution. The resins may be urea- or melamine-aldehyde resins. The resin-forming components may be added to an acidic solution, or an acid may be added to a solution of the resin components, or one component and an acidic substance may be present originally in the solution and the other component subsequently added. The resin-forming components may be added as solids. The aldehydic component may be paraformaldehyde or hexamine. An intermediate condensation product may be trimethylol melamine, tetramethylol melamine or dimethylol urea. The acid may be sulphuric, phosphoric, oxalic, tartaric or acetic, and may be added to the solution by continuous drip feed or in portions at intervals, or the solution may include an ammonium salt which develops acidity by reaction with formaldehyde. Alternatively, the acid may be introduced into the solution by using carbonized or acid-milled woollen material. After impregnation excess liquid is removed from the material, which may then be rinsed and dried. The solution may include a wetting agent, and after the treatment surface deposits may be removed from the material with dilute phosphoric acid. After an impregnation the solution may be prepared for re-use by first neutralizing it at an elevated temperature with ammonia or caustic soda, then adding resin-forming components or condensation products to replace the resin taken up by the fabric, and acidifying the solution. The solution may include an acid dyestuff, and the material may be pretreated or after-treated, if necessary, with a dichromate and a wetting agent, or the solution may include a dyestuff, sodium or potassium chromate and ammonium sulphate. In examples the solution comprises (21) Lissamine green, Glauber's salt, sulphuric acid, trimethylol melamine and p formalin; (22) Coomassie red, Glauber's salt, acetic acid, trimethylol melamine and formalin; and (23) Carbolan blue, ammonium acetate, trimethylol melamine and formalin. In other examples (24) wool fabric is treated with sodium dichromate and cream of tartar and is then impregnated with a boiling solution comprising Solochrome Azurine, a wetting agent, trimethylol melamine, formalin and acetic acid; (25) wool fabric is treated in a boiling bath comprising Solochrome Azurine B.S., a wetting agent, Glauber's salt, trimethylol melamine, formalin and acetic acid to which is later added formic acid and finally sodium bichromate; (26) wool fabric is treated at 95 DEG C. in a bath comprising Solochrome Azurine B.S., ammonium sulphate, sodium chromate, a wetting agent, trimethylol melamine and formalin.