RU2257434C1 - Cotton fabric dyeing process - Google Patents

Abstract

FIELD: textile industry.

SUBSTANCE: invention proposes sulfur dyes for dyeing cotton fabrics utilizing process consisting in impregnating fabric with sulfur dye, seaming, treating sheet with ozone-air mix, washing while simultaneously introducing ozone-air mix into wash water in order to remove dye from waste water, and drying.

EFFECT: intensified dyeing process, increased strength characteristics of dyed fabric, and performed cleaning of waste water.

1 dwg, 2 tbl

Description

The invention relates to the textile industry of light industry, namely, dyeing of cotton fabrics with sulfur dyes.

Known alkaline-reduction method of dyeing with vat dyes, which consists in adding tissue to a solution of a reduced dye, steaming, oxidizing treatment, washing with a detergent solution and drying [1].

There is also known a method of continuous dyeing with sulfur dyes, used at textile enterprises, which consists in impregnating the fabric on top with a solution of the restored dye, steaming in a steam roller chamber, oxidizing with cold water in the first bath, washing the fabric in the second, third, fourth washing baths with hot water with the use of textile detergent 1-2 k / l and drying on drying drums [2].

This method is the closest to the claimed invention in technical essence and the achieved result.

The disadvantages of the described methods are: low selectivity of the dye with a cotton cloth and severe contamination of the wash water.

The objective of the invention is to intensify the dyeing process in the direction of the beneficial use of the dye, increasing the strength properties of the dyeing of a cotton cloth while cleaning the wash water.

The technical result is achieved by the fact that in the method of dyeing cotton fabric, which consists in impregnating the fabric with a solution of sulfur dye, then steaming the impregnated fabric, washing and drying it, according to the invention, between the operations of steaming and washing, the fabric is processed by oxidation in the chamber with an ozone-air mixture, after which excess ozone-air the mixture is fed into the wash water for wastewater treatment from the dye.

There is also a method of processing textile material, which consists in impregnating it with a dye solution, processing with ultraviolet radiation, impregnating and drying [3].

However, this method does not provide the required color indices, especially in terms of abrasion resistance, and pollutes waste water due to incomplete oxidation by ultraviolet radiation.

The intensification of the dyeing process, the increase in the strength properties of the dyeing of a cotton cloth with the simultaneous purification of washing water are achieved due to more intense oxidation of the dye on the canvas after the steaming operation.

In addition, the achievement of the technical result is confirmed by the test results (see tab. 1 and 2).

The drawing shows a diagram for implementing the inventive method, where the positions 1-7 indicate the following elements of the device:

1 - plus for impregnation,

2 - a steam chamber for steaming,

3 - chamber for ozonation,

4 - pipeline for supplying the ozone-air mixture in the first wash bath,

5 - washing baths

6 - dryer

7 - rolling machine.

An example of the practical implementation of the method.

To test the method, a laboratory stand was developed and manufactured, which allows dyeing of the fabric both according to the prototype technology and according to the claimed method, for which a chamber for processing the textile fabric with an ozone-air mixture was introduced into the stand.

The sequence of operations for the prototype is as follows: impregnation of the canvas, its steaming, washing and drying.

The sequence of operations according to the method of the invention: impregnation of the fabric with sulfur dye, its steaming, oxidation of the fabric in the chamber with an ozone-air mixture under pressure, washing with simultaneous processing of washing water and drying.

The effectiveness of dyeing methods is characterized by the intensity and strength of the color. The intensity was determined spectrophotometrically using a Spekol instrument, and the color fastness was determined in accordance with GOST 9733-61. The test results of the fabric dyed by the compared methods are shown in table 1.

Table 1 Test results of textile samples dyed with sulfur dye black No. Way Intensity, K / S * Color fastness Wash 60 ° To rubbing over friction To wet wiping dry wet 1 According to the prototype 0.78 4/4/4 4 2-3 3 2 The claimed 0.94 4/5/5 4-5 3-4 4-5 * K / S is determined by [4].

Wastewater was also tested after washing the textile web without ozonizing effluents and with ozonation. The test results are shown in table 2. The color was evaluated by optical density, which was determined on the device KFK-2 (concentration photoelectric colorimeter).

table 2 Wash Water Test Results Way Chromaticity D (λ = 540 nm), (nm) 1st wash bath Oxidation of COD, mg O ₂ / l Color (hot water + textile detergent), (nm) According to the prototype 0,800 52.84 0.67 According to the invention, with ozonation 0.508 36.46 0.31

In the method according to the invention, the ozone-air mixture is supplied directly to the tissue swollen after steaming under pressure. As a result, the dye is rapidly and completely oxidized uniformly throughout the structure of the fabric, and not just on the surface. This provides intensive, uniform coatings with the necessary indicators of abrasion resistance. Complete oxidation of the dye to an insoluble pigment significantly reduces the pollution of wash water. Moreover, this method is especially effective when using sulfur dyes.

As a result of the application of the invention, the color intensity of the canvas increased by 17%, the strength of the color increased by 1 point. The color of cold wash water in an oxidizing bath decreased by 36%, in a hot wash bath with the addition of a fine detergent by 53%. This creates the prerequisites for the regeneration of detergents. A sharp (31%) decrease in the oxidizability of wastewater indicates the breakdown of sulfur-containing reducing agents, which helps to eliminate one of the main disadvantages of sulfur dyeing.

List of sources used

1. Physico-chemical fundamentals of the processes of finishing production: Textbook. manual for universities / B.N. Melnikov, T.D.Zakharova, M.N. Kirillova. - M .: Light and food industry, 1982, - p.198.

2. Finishing cotton fabrics: Handbook edited by B.N. Melnikov, - Ivanovo: publishing house "Talka", 2003, - p.208.

3. RF patent No.2010617, IPC B 05 C 3/12, 1994.

4. Laboratory workshop on the chemical technology of fibrous materials: Textbook for universities (T.S. Novoradovskaya and others. Edited by G.E. Krichevsky). - M., 1994, - p. 310.

Claims (1)

The method of dyeing cotton fabric, which consists in impregnating a solution of sulfur dye, then steaming the impregnated fabric, washing and drying it, characterized in that between the operations of steaming and washing, the fabric is processed by oxidizing the ozone-air mixture in the chamber, after which excess ozone-air mixture is fed into the washing water for wastewater treatment from dye.