What is cheese dyeing? Cheese dyeing is a method of dyeing yarn. It is wound on a special plastic bobbin with small holes through a spool car to allow the dye to penetrate into the cheese. The cheese dyeing process is a chemical change and requires pre-treatment, Enter the vat for high-temperature dyeing, dehydration and drying and other steps to turn the grey yarn into cheese yarn.
For cheese dyeing, the cotton embryo yarn or blank shaft that needs to be dyed according to the plan is dropped into the dyeing vat under computer control. After chemical treatment in the high temperature and high pressure dyeing vat, the embryo yarn is processed into various customer needs. For white yarn and dyed yarns of different colors, the textile industry mainly uses Sanshan color card and Pantone color card. Of course, the colors include Fuchun White and Fuchun Black.
1. Pre-treatment: The pre-treatment is mainly to remove natural impurities in the yarn, such as: unremoved cotton seed hull, wax and other pigments, to improve the whiteness of the package yarn to create conditions for dyeing processing. Higher-quality pre-treatment can not only improve the brightness of the yarn but also improve the wet friction of the yarn.
2. Dyeing: cheese dyeing can be said to be a very ancient process. Different fibers also have different dyeing characteristics, and various dyes also have different dyeing methods. The same is that their dyeing has a dyeing process. . The so-called dyeing is a process in which the dye is gradually transferred to the fiber after it becomes the dye solution and gradually penetrates into the yarn fiber.
3. Post-processing: The post-processing of yarn is divided into three steps:
①Soaping: After the cheese is dyed, a large amount of hydrolysates and unreacted dyes remain in the dye liquor and on the surface of the yarn, and these residual dyes must be removed by washing with a soaping agent at a high temperature of 100° . Its function is to remove the floating color on the yarn and improve the vividness of dyeing, so as to meet the color fastness requirements of customers.
②Fixation: After the soaping is completed, for dark and medium colors, in order to achieve their non-fading color in the subsequent desizing and mercerizing process, a fixing agent needs to be added to fix the color. Fixing agent is a kind of polymer chelate, its function is to form a protective film on the surface of the yarn, so that the dye on the yarn will not fall off during finishing and processing.
③Too soft: When the yarn is dyed, the natural wax on the surface of the yarn will be damaged, which will increase the friction between the sand and river threads and harden the hand. After the dyeing is completed, the yarn needs to add silicone oil and other compounds. In order to reduce the friction between the yarn and the yarn, it is convenient to protect the luster and feel of the colored yarn and facilitate unwinding.
In short, the dyeing process of yarn is formulated according to the characteristics of cotton fiber and reactive dyes. The time to dye a cylinder of white yarn is about 4-5 hours, while the time to dye a cylinder of colored yarn takes 8-13 hours. In the dyeing vat, a pressure pump applies pressure to the dyeing liquor in the dyeing vat, so that the dyeing liquor can penetrate from the outer layer of the package to the inner layer, or from the inner layer to the outer layer, so as to achieve the purpose of bleaching and dyeing the package evenly.