A good printing and dyeing process determines the color fastness of fabric and clothes. The following are common processes on the market: reactive dyes Silk charmeuse The dying used in traditional printing and dyeing processes are mostly direct, acidic and neutral dyes. Most of the color fastnesses are onlylevel 3, and the deep color is still far from this index. Therefore, to make real Silk charmeuse truly reach the goal of washing and wearing, it is necessary to solve the problem of color fastness.
At present, there are fatal weaknesses in the dying and printing processes used in Silk charmeuse printing and dyeing, which are mainly manifested in the following five aspects:
(l) Most dyes used in Silk charmeuse printing and dyeing are weak acid dyes, neutral dyes and direct dyes. , Printing, dyeing and taking process cause pollution to the environment. Such as: excessive metal chromium ions in the production process of neutral dyes seriously pollute the environment. Some countries in Germany and Europe have proposed strict control of the residual amount of heavy metal ions in textiles.
(2) The fastness of wet treatment is poor. Generally, the dark and medium colors are about 2 to 3 grades, and the dyeing and printing of individual dyes are only about 2 grades. The performance of taking it can not be washed in the same bath with other months and equipment. At the same time, it will cause light color due to fading. Get old.
(3) The sun fastness is poor, generally only about l-2 grade, especially the bright green lotus, lake blue, brilliant blue and other colors, it will fade after a summer, lose the timeliness of taking, and cannot be consumed by the majority Accepted by the person.
(4) With the gradual maturity of anti-shrinkage and anti-wrinkle finishing technology, the disadvantages of washing, such as fading, staining, and oldness, are becoming more and more prominent, and it does not solve the problem of color fastness. It is really "washable and wearable" in the true sense.
(5) Whether it is a domestic product or an export product, it is generally required to print and dye real Silk charmeuse with high fastness (washing and soaping fastness requirements above 4; wet rubbing fastness above 3), the current factory can not be industrialized production. There is an urgent need to solve this problem. In recent years, with the development of the chemical industry, a number of new reactive dyes have been developed, and the performance of printing and dyeing has been rapidly improved. The reactive dyes have a high dyeing rate, level dyeability, fixation rate, improvement rate, and stability. There have been great improvements in terms of performance and process sensitivity, which laid the foundation for the development of reactive dye printing and dyeing processes. Therefore, it is the most important task to be solved in the current silk charmeuse industry to accelerate the resolution of the weakness of the Silk charmeuse products such as fading and aging, accelerate the research on the printing and dyeing process of the reactive dyes of Silk charmeuse, and develop new high-fastness Silk charmeuse products.
Adding environmentally friendly reactive dyes Increasing environmentally friendly dyes not only requires no pollution or less pollution in the production process of dyes, but the reactive dyes produced by the project are less polluted during the printing and dyeing process, and the processed clothing must meet environmental protection requirements. Some of the prohibited dyes have been substituted, and a batch of reactive and reactive reactive dyes have been developed in recent years.
Reactive dye dyeing process :
Acid bath method The acid bath method is suitable for the dyeing of Silk charmeuse and viscose jacquard cross fabrics. The neutral bath method or alkaline bath method will make the viscose pattern stain or color. Process flow: fabric treatment → dyeing → pickling → soaping → water washing → cold water roll. The application of reactive dyes on textile fibers should have at least the following conditions: high water solubility; high storage stability; not easy to hydrolyze; high reaction to fiber and high fixing rate; chemical stability of the bond between dye and fiber High, that is, it is not easy to break the bonds during use. It has good diffusibility, level dyeing and good dye penetration; various dyeing fastnesses, such as sunlight, climate, washing, friction, chlorine bleaching resistance, etc. . There are more special requirements for dyes for silk satin printing:
Printing process flow: grey Silk charmeuse preparation → printing → drying → steaming → washing → soaping → washing → drying.
(l) Steaming: After the fabric is printed and dried, it needs to undergo a steaming process to dissolve most of the dye remaining in the slurry film in the presence of water, transfer to the fiber, and diffuse into the fiber. The selected steaming equipment is to hang the fabric on the star rack and put it into the steaming box for steaming.
(2) Soap washing: The fixing rate of general reactive dyes is only about 70%, and the high ones are only 80%. Unfixed dyes dissolve into the washing liquid during washing, and when the concentration of dye in the washing liquid is high, Stained fabric due to fiber absorption. Therefore, reducing the dye concentration in the wash solution as much as possible is a measure to reduce contamination. First wash with cold water, then hot water, soap, and finally hot water and cold water.