SU118223A1 - Method of bleached linen yarn - Google Patents

Description

There are known methods for bleaching yarn with alkali hypochlorite peroxide method and alkali peroxide method.

The disadvantages of these methods are that they require substantial costs of steam, water and electricity.

In the process of cooking, along with hydrolysis, emulsification and dissolution of impurities, some of their condensation reactions take place, which largely cause darkening of the yarn (or fabric). Removal of condensation products presents known difficulties.

The described bleaching method by oxidative cooking reduces these drawbacks, reduces the bleaching process and improves the quality of yarn.

For this purpose, alkaline decoction and bleaching with hydrogen peroxide at a temperature of 90-100 ° for 1.5-2 hours are combined in one process.

Before the process, the yarn is treated for 25-30 minutes. circulating cold working solution.

In the presence of flax yarn microflora, the yarn is pretreated with mineral acid or soda ash solution, or with hot water, with or without a wetting agent, or with hot air, or steam.

The method is carried out as follows.

Before oxidative cooking, flax yarn is processed for 30-40 minutes. one of the following reagents: weak mineral, for example, sulfuric acid, cold acid; weak solution of soda ash at a temperature of 70-80; hot water at a temperature of 90 ° C with or without a wetting agent, with hot air at a temperature of 90-100 ° C, or steam.

Then, after appropriate washes, the yarn is subjected to oxidative boiling in a bath containing 1 silicate, soda ash, caustic soda and hydrogen peroxide. In the case of hard water, calgon is given. Depending on the module of the bath, the number of reagents is Berel -118: HZ-o -

with various. For example, for a 1: 8.5 module, the active oxygen concentration is 1.7-2.0 g / l; alkali concentration, calculated on caustic soda, 4.2-6.0 g / ug; silicate concentration of 5.5-6 g1l.

First, the process is treated in a cold peroxide solution for 30 minutes, after which the temperature is gradually raised to 90-100 ° and the treatment is continued for 1.5-2 hours. The total duration of the bleached yarn process is 3-3.5 hours.

After appropriate washing, the yarn is dried.

In the presence of hard water, additional kislovka is carried out followed by flushing.

Subject invention

Claims (3)

1. A method of bleaching yarn by oxidative cooking, characterized in that, in order to reduce the process and improve the quality of the yarn, combine alkaline decoction and bleaching with hydrogen peroxide at a temperature of 90-100 ° for 1.5-2 hour. 2. Acceptance of the method according to claim 1, characterized in that prior to carrying out the process, the yarn is treated for 25-30 minutes. circulating, working, cold solution. 3. Acceptance of the method according to Mon. 1 and 2, distinguished by the fact that, in order to ensure the correct flow of the combined process in the presence of flax right microflora, the yarn is subjected to a preliminary treatment for 30–40 minutes before carrying out the process. weak mineral, for example, sulfuric acid, cold or a weak solution of soda ash at a temperature of 70–80 °, or hot water at 90 ° with or without a wetting agent, or hot air at a temperature of 90-100 °, or { ferry.