SU35810A1 - The method of accelerated bleaching in rasparovka cotton and fabrics mixed with artificial silk - Google Patents

Description

The proposed method aims to accelerate the bleaching of cotton or silk-blended fabrics into silk by boiling them in the presence of alkali salts and emulsifying substances, with or without subsequent treatment with bleached solutions. The existing fabrics for fabrication into a raspravka are based either on the use of elevated pressure and high temperature or on a change in the duration of the decoction.

The duration of the decoction process and the need to apply high temperature and pressure make it difficult to design appropriate equipment, since in the case of high temperatures, the devices are very complex in design and inconvenient in operation (Welter, Müntad and Rovira), in the case of increasing the productivity of the apparatus decreases sharply (Botterworth).

The method of bleaching cotton products proposed by the authors of the present invention in 1929 (the accelerated emulsion method, bleaching, described in the author's certificate No. 15649), made it possible to reduce the decoction time to one hour and hold it at a temperature; do not exceed 51)

95-97 ° through the use of cooking liquor for cooking, which ensures the cleaning of products from impurities to be removed in the shortest possible time. Thus, a reduction in the decoction time and a decrease in its temperature (decoction without pressure) were compensated for by the increased activity of the working liquor.

The authors' proposed method of bleaching cotton fabrics mixed with artificial silk is aimed at further (as compared with the method published in the author's certificate No. 15649) reducing the boiling time with sufficient effect of cleaning the fabric and without using increased pressure, which is achieved as a result of increased exchange of lye in the thickness of the fabric, carried out by evacuating the liquid from the thickness by the last action of the steam jet, thus preparing the fabric for impregnation with a new amount of working liquor.

The method consists in that cotton or fabric mixed with rayon is treated in a closed apparatus (without the use of elevated pressure) with a weak solution of caustic alkali (3-4 ° Vyo) containing highly wetting and emulsifying

substances (e.g., T contact, Necale, soaps, tar soaps, sulphurization, etc.), as well as some alkali metal salts (silicates, sodium or potassium sulfite, etc.) The above treatment is carried out at not exceeding 100 ° by repeatedly soaking the fabric with the working solution followed by the direct jet of steam. Overall, the operation varies, depending on the type of fabric, from 4 to 7 minutes. After this operation, the product is thoroughly washed first with hot and then with cold water and treated with bleaching solutions (lime lime, sodium hypochlorite, hydrogen peroxide, etc.), after which it is acidic, washed again and dried in the usual way. In the case of preparation of goods for medium and dark dyeing, the process can be completed by washing after boiling. In some cases, preliminary preparation of the goods, as provided for in the author's certificate K 13109, can be done by impregnating the goods before boiling with caustic soda solution containing some wetting agent, with or without the addition of silicate, sulfite, . The above treatment of the product before decoction with diastasis-containing preparations, hypochlorite, peroxides, etc., enhances the cleaning effect of the fabric during decoction, but is not absolutely necessary.

Working liquor used for ho; It is approximately as follows:

10-35 g of sodium hydroxide 5-15 "contact T 7.5-25" sodium sulfite 5-15 "sodium silicate 39 ° Ve water

1000 g

Sodium sulphite may be replaced by potassium sulphite, contact by other T-products with sufficient wetting and emulsifying properties.

The subject matter of the invention.

1. A method for bleaching cotton and mixed with artificial silk fabrics by alkaline cooking in the presence of wetting substances and alkaline salts followed by treatment with bleaching solutions, or without it, characterized in that the fabric is alternately impregnated with the above designations it is heated at a temperature not exceeding 100 ° and exposed to a direct stream of steam in order to displace the solution from the fabric.

2. Accepting the implementation of paragraph 1 of the method, characterized in that the fabric prior to the boiling is subjected to pre-treatment set forth in patent No. 13109.