CS217562B1 - Method of washing textile materials after printing and dyeing with anionic or disperse dyes - Google Patents

Abstract

A method of washing textile materials after printing or dyeing with anionic or disperse dyes using sorption materials, in which the washing is carried out at a bath pH value of 2 to 6 in the presence of particles of a polyamide-based polymer sorbent with a specific surface area greater than 5 m2.g-1.

Description

The invention relates to a method of washing textile materials after printing and dyeing with anionic or disperse dyes using polymeric polyamide-based sorbents. In principle, it is based on a combination of physical sorption and chemisorption, which ensure the removal of excess free dye from the washing system. The preferential sorption of this free dye onto the sorption polyamide powder prevents its re-settling onto the washed textile material.

Thus the whiteness of the prints is achieved and at the same time the color and print stability is increased. Another advantage of the process is the possibility of obtaining technological washing water of original purity and temperature of the washing, which can be reused. The dye trapped sorbent can be regenerated with an organic solvent so that it can also be reused.

The present process ensures, in contrast to the methods currently used, complete removal of the dye released in the washing process after printing or dyeing from the washing system. This avoids the redeposition of the non-fixed dye back to the actual textile substrate, which makes it difficult to obtain whitish prints and, in addition, significantly deteriorates the stability of these prints or dyeings.

These problems are particularly pronounced in the processing of mixed textile fabrics by combining different types of organic dyes. In some cases, the possibility of using certain combinations of dyes with subsequent washing by classical methods is excluded, since embedding in white pools cannot be prevented. The proposed process, however, allows the use of these blends to achieve brilliant tones.

Conventional methods of washing also cause other problems in the field of ecology and energy intensity, resulting from the pollution of washing water by the dye removed. Due to the large volumes of such processed goods and high water consumption, the proportion of waste water polluted in this way in the total volume of refining plants is very high.

With few exceptions, the washing processes currently in use are unable to solve the problems outlined. A partial solution is to mark the procedure according to MS. No. 193 247. While it achieves some improvement in the above-mentioned technological properties of prints, the environmental issue and the overall energy balance of the process remain unresolved. The proposed processes using organic sorption polymer powders, in our case based on polyamide, in process washing processes are not otherwise known. The advantages of these processes are not only a significant improvement of the technological results of the prints, but also the opening of the possibility of recirculation of water of unchanged purity and related savings connected with its heating, as well as a positive impact on the ecological sphere.

It is an object of the present invention to provide a dye not fixed on a textile substrate which is removed from the material by a washing process. . 4 is adsorbed to the surface of the polyamide-based polymer powder, while at the same time chemisorption to the polymer component added to the wash liquor takes place. The released dye is constantly removed from the washing system by sorption competing with undesired dye re-sorption (redeposition) to the textile substrate. In addition to the possibility of utilizing the improved affinity of the polyamide sorbent to certain types of dyes, as opposed to the actual fabric substrate to which other synthetic fiber components are added, the sorption advantage is ensured by a substantially higher adsorption and diffusion rate. The textile substrate itself is formed by an oriented, compact polymer with a low surface area. In the case of a polyamide sorption powder, the dye trapping is aided by shifting the pH of the washing system to the acidic range (ph = 2 to 6).

Polyamide powder with a porous structure and large specific surface area can be prepared by caprolactam melt precipitation according to the GDR pat. No. 8027. Waste in the manufacture of fibers or other polymeric products can be advantageously used to prepare the sorbent powder for the proposed use in the washing process. This gives the possibility to efficiently utilize this waste, the amount of which is large in relation to the total fiber production volume and constitutes a sufficient raw material base for the preparation of sorbents. In case of regeneration of the sorption powder, its multiple use is guaranteed.

By preferential sorption of the released dye to the present sorption polyamide powder, the present process ensures whitish prints, even for mixed textile materials printed with dye combinations. The proposed process makes it possible to use for printing purposes also for the purposes of a non-traditional group of dyes and their combinations, which achieve brilliant shades and their application is economically advantageous. Their hitherto application is prevented by the incorporation of unfixed dye into uncovered textile substrate collections in conventional washing processes (eg printing of PES / ba or PES / VS mixtures by combination of disperse and reactive dyes J).

In addition, the process ensures high stability achieved on printed or dyed textile materials.

A further advantage of the invention is to obtain the washing water used in the initial purity, which can be recycled again in the process process after removal of the sorption powder by the quantitatively retained dye. This affects not only the total, in this case particularly high, water consumption, but also the resulting energy balance, since pure water recovered by this process has a temperature corresponding practically to the temperature of the washing process carried out.

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Example 1

PES / ba fabric (65/35) was printed with a combination of disperse and reactive dye:

g C.I. Disperse Red 121, 20 g C.I. Reactive Red 24 per 1 kg of printing paste with semi-emulsion throat of conventional composition. After the prints were fixed by HT steaming (180 ° C / 6 minutes) and by thermofixation (200 ° C / 1 minute), the samples were subjected to a washing process according to the following scheme:

1. prewash - running water, 3 minutes

2. sorption washing - bath 1: 60, temperature 85 ° C, 5 minutes bath composition:

polyamide sorbent powder (type PAD 6) 10 g / l acetic acid (99%) 1.5 ml / l

3. sorption washing - bath 1: 60, temperature 85 ° C, 10 minutes bath composition:

polyamide sorbent powder (type PAD 6) 5 g / l acetic acid (99%) 1.5 ml / l

4. rinse hot water running 1 minute cold water running 1 minute

The same washing procedure was applied to other color combinations of the mentioned dye types on the PES / ba composite material (65/35). In all cases, brilliant, whitish prints with improved durability were achieved, especially in water and underwear. The initial purity of the wash water from operations 2 and 3 was not changed after removal of the sorption material. Pure recirculating water had a wash temperature.

Example 2

The washing process of Example 1 was treated with a 50/50 semi-linen linen / ba fabric printed with a combination of 500 g CI Reactive Blue 25, 500 g CI Reactive Blue 13 - pur 50 g. kg ^-1 paste. The whiteness of the prints has been greatly improved compared to the comparative result of a conventional washing procedure. The initial purity of the wash water remained unchanged.

Example 3

The washing process of Example 1 was used to treat a mixed VS / PES fabric (85/15) with a combination of reactive and disperse dyes

13.5 g C.I Disperse Blue 56, 27 g C.I. Reactive Blue 5, 2 g C.I. Disperse Red 121,

2.5 g C.I. Reactive Red 24 per kg of paste with semi-emulsion thickened paste after HT fixation by steaming (180 ° C / 6 minutes) or thermofix (200 ° C / l minute). The results obtained were identical to those obtained in Example 1.

Example 4

For washing the printed or dyed textile substrates of Examples 1-3, a polymeric sorption material of the PAD 66 type (poly-hexamethylene diammonium adipate) was used with the same results instead of the PAD 6 polymer polyamide sorbent (polycaprolactam).

Example 5

Instead of the dry powder forms of the polymeric materials of Examples 1 and 4, a suspension of these polyamide sorbents in water was obtained under the same conditions, obtained by omitting the drying phase in the sorbent preparation. Under the application conditions of Example 1, the same technological effects were achieved. The wash water obtained was reusable in the wash process after the sorbent was removed.

Claims (2)

A method of washing textile materials after printing or dyeing with anionic or disperse dyes using sorption materials, characterized in that the washing is carried out at a pH of 2 to 6 in the presence of particles of polymeric sorbent based on polyamide having a specific surface area of more than 5 m ² . g ^-1 · 2. A method according to claim 1, characterized in that the washing water is used in a closed cycle.