What are the characteristics of cold pad dyeing?

Cold pad-batch open-width dyeing is a semi-continuous dyeing process. Compared with the traditional dip dyeing, two-phase continuous steam pad dyeing, and wet short steam continuous pad dyeing, it has the following characteristics:

1 High fixation rate

During cold pad-batch dyeing, the dye and alkali in the dyeing solution are in the same bath and stacked for a long time at room temperature. Therefore, during the dyeing process, the three stages of adsorption, diffusion and fixation of reactive dyes are carried out slowly at the same time. The hydroxyl groups in the cellulose fiber react to form ether bonds. The ether bonds have high acid hydrolysis resistance and also play a leading role in improving the fixation rate. Due to the low temperature and the slow reaction of the dye fixation time, the hydrolysis of the dye is reduced and increased The probability of dyeing cellulose on the dye is improved, and the fixation rate of the dye is improved; the fixation rate is improved, the dye hydrolysis is less, the dry rubbing and wet rubbing fastness are also improved, and the chromaticity of the sewage that removes the floating color is also greatly reduced.

The cold pad-batch dyeing process, and the two-phase continuous pad-dyeing and steaming process, the three stages of adsorption, diffusion, and fixation in the dyeing process complete the dyeing process in a relatively short time, and require a strong alkali agent. The dye reacts with the fiber and fixes on the fabric, causing part of the dye to be hydrolyzed, which can save 10% to 20% of the dye. Therefore, cold pad-batch dyeing and dark dyeing have obvious advantages.

2 Small head-to-tail difference

Compared with immersion jig dyeing, cold pad dyeing has smaller color difference between coil and coil, head and tail, and the reproducibility of selection is good. Because "cold pile" also saves steam, but the reaction time is longer.

3 Save energy

Compared with the two-phase continuous pad dyeing process, the cold pad-batch dyeing process does not require the cold pad-batch dyeing process. In the two-phase continuous pad dyeing process, the fabric needs to go through far infrared rays, pre-drying, drying drum, The drying process of the dryer is the steaming and fixing process of immersing in salt and alkali fixing liquid after drying, thus greatly reducing the power consumption and hot steam consumption of the machine, and significantly reducing the energy cost.

4 The cold pad-batch dyeing process does not need to be stacked after dipping the pad dyeing solution. The drying process of the traditional active two-phase process not only saves energy, but also overcomes the migration of dyes during the drying process. The disadvantages of the chromatic aberration in the edge are especially suitable for thin fabrics due to uneven drying, resulting in color streaks and blooms on the cloth surface, as well as to avoid wrinkles produced during drying of high-woven and high-density fabrics. It is more suitable for the production of velveteen fabrics, corduroy and other products. The bottom is white and uneven.

5 Compared with wet short steaming process, cold pad-batch dyeing has good consistency of color difference before and after, energy saving, high dye fixation rate, good product stability and good reproducibility.

6 The cold pad dyeing process equipment is simple, the equipment investment is small, the process is short, the equipment cleaning is easier, the production preparation time is less, and the production labor is less. It is suitable for the production of small batches, multiple varieties, and multiple color positions. It can also be combined with two-phase production. The method is the same as the continuous pad dyeing process, producing large batches of color positions, and the consistency of the front and back is relatively stable.