Views: 1000 Author: Site Editor Publish Time: 2021-11-17 Origin: Site
Reactive dye digital printing without steaming and washing:
Because the current process of reactive digital printing must be sizing, steaming, and washing, the process is cumbersome and the quality control requirements are high. Many people are inspired by the decentralized digital thermal transfer and want to achieve the reactive printing process without steaming and washing just like thermal transfer. People follow what they like and claim that they have developed active digital printing non-steaming and washing technology
Why is it unreliable to say that reactive dye printing does not need to be steamed and washed? Recently, some people have promoted that reactive dye printing can be steam-free, and the finished product can be obtained by drying after printing.
Reactive dyes, as the name suggests, are alive. Anything that is alive has the possibility of dying. What are the dead reactive dyes? It is a reactive dye that is hydrolyzed, and its reactive group loses the ability to form a covalent bond with the fiber. In the production process of reactive dyes and during storage, hydrolyzed dyes are formed. During the printing process, a large number of hydrolyzed dyes are also formed. For the multi-reactive dyes with the highest dye uptake rate and fixation rate, the fixation rate can only reach about 90%, while the conventional reactive printing monochloros-triazine The fixing rate of the active base is generally about 70%, which means that there are 10-30% of the dead hydrolyzed dyes in the active printing, which needs to be washed off after the printing is finished, otherwise the color fastness of the final product will be seriously affected.
In addition, in reactive printing, in order to absorb water during steaming, there is a large amount of urea. In order to ensure the sharpness of the outline, there is a large amount of printing paste. In order to provide alkaline conditions, a large amount of alkali agent is added, which must also be removed by washing. Otherwise, the physical and chemical indicators are unlikely to meet the standards, and the performance is lost.