In order to increase the color and finish of indigo denim, the color (original) denim mainly includes bromine indigo (commonly known as turquoise blue in the market) denim and vulcanized black denim, super indigo" on Colored denim has two major characteristics: the color depth is very deep and the fastness to scrubbing and dyeing is very good.
Because the workwear made of super indigo color or extra deep indigo color denim can obtain the special effect of strong and bright color after being polished and finished, it is widely welcomed by consumers.
"Super Indigo" colored denim has two major characteristics: that is, the depth of color is very deep and the fastness to washing and dyeing is very good. The former refers to the amount of indigo dye dyed on the spinning yarn per unit weight (generally expressed as% of the dry weight of the dye, referred to as the color depth %). For example, the indigo color depth of conventional denim warp yarn is 1% ～3%, and the color depth of "Super Indigo" needs to reach 4% or more before it can be called Super Indigo or Extra Deep Indigo. The latter means that the "super indigo" colored denim needs to withstand repeated scrubbing and washing for more than 3 hours, and its color can still reach or exceed the color depth of conventional colored denim without scrubbing, and its color finish is better than conventional The colored denim is much brighter and brighter. For the scrubbing and dyeing fastness of indigo-colored denim, its essence depends on the degree of penetration of the dye to the spinning yarn, rather than the scrubbing fastness of the dye itself (the wet fastness of indigo is only level 1). That is, the better the degree of core penetration, the better the fastness to washing and dyeing.
Because the coloring depth of super-indigo denim is increased by more than 60% compared with conventional traditional denim, the indigo concentration of the dyeing solution will also be doubled, even reaching 3 to 4g/L. Deep color. In this way, the viscosity of the dye solution increases and the fluidity becomes poor, which affects the penetration ability of the dye leuco body, and reduces the fastness of the denim to the scrubbing and dyeing, which cannot meet the final depth requirements of the workwear production. The higher the concentration of indigo in the dyeing solution, the heavier the redness of the colored material and the darker the color, and there will be no "super indigo" effect. Therefore, at present, many production plants have or are planning to transform dyeing and pulping equipment to solve this problem by increasing the number of coloring channels. The dye uptake rate is the highest and the color is stable. At the same time, the color tension of the warp sheet is appropriately reduced to obtain a better "super indigo" coloring effect.
Colored denim with indigo as the base color In order to increase the color and color changes of indigo denim varieties, various colorized denim varieties are currently extremely popular. For example, indigo over-dyeing sulphur black, indigo over-dyeing sulphur grass green, sulphur black green, sulphur blue, etc., to meet the individual needs of the market. At the same time, denim manufacturers have their own patented new denim varieties to improve market competitiveness. In this regard, it should be noted that it is possible to control the concentration of the mother liquor properly to prevent excessive overflow of the dye liquor and cause the waste of dye and expand the pollution to the environment.
Colored denim mainly includes bromine indigo (commonly known as turquoise blue in the market) denim and sulphur black denim, as well as coffee, emerald, gray, khaki, sulphur blue denim with sulphur dyes and a small amount of naftor dyes. Or the scarlet, pink, concubine denim colored by reactive dyes, etc., although the production volume is not large, the market demand is relatively urgent and often cannot meet the needs. The main problem is that the color finish is not stable enough, and the emphasis on coloring is also poor. The workwear manufacturer does not like it. Of course, this is related to the small production batch and too many colors. Large, high consumption, high cost, and difficult to treat sewage, etc., also have a positive impact. The first solution is to reduce the number of color combinations during the design process. It is possible to use two color combinations, and at most three color combinations, or use other more stable dye varieties to replace them to adapt to the production characteristics of the dyeing and sizing machine. More stable coloring effect; Second, the more thorough solution is to adopt the yarn-dyed factory spinning high-capacity coloring, and the production process route of split warping to produce colored denim is ideal.