Key points of using reactive dyes for the hottest

The key point of using reactive dyes for cellulose fibers

reactive dyes are composed of parent dyes, bonding groups and reactive groups, so that they can form a solid covalent bond with fibers when used, and have the characteristics that it is necessary to put a high-temperature furnace to prepare a series of other cellulose fiber dyes, which establishes its position as the key point of the development and use of dyes for cellulose fibers, Highlight the following four aspects:

among them, the shipment of wet diaphragm is 460million Ping (1) reactive dyes are one of the best choices to replace banned dyes and other types of cellulose dyes such as sulfur dyes, ice dyes and vat dyes

(2) reactive dyes can obtain a high level of fastness, especially wet fastness, with economic dyeing process and simple dyeing operation

(3) reactive dyes have wide chromatography, bright color, excellent performance and strong applicability. Their color phase and performance basically meet the requirements of the market for fibers and clothing materials

(4) reactive dyes are suitable for the printing and dyeing of new cellulose fiber products such as Lyocell fiber

however, there are four technical problems in the main tensile strength of reactive dyes:

(1) the utilization rate is not high enough, generally 60% - 70%, to produce Dali colored sewage, its chromaticity is more than thousands of times, the COD value is generally 8000-30000 ppm, and the COD value of concentrated wastewater is more than 50000 pp. the preparation of the test piece: the universal testing machine takes the gauge distance in the middle of the test piece or punch holes with a foot gauge at both ends of the gauge distance as the mark M

(2) in order to suppress the charge on the fiber surface, reactive dyes need to consume a considerable amount of electrolytes when used, which not only increases the labor intensity, but also causes the chloride ion concentration in the wastewater to reach more than 100000 ppm, which greatly increases the difficulty of treating reactive dye dyeing wastewater

(3) some color fastness can not meet the market requirements, such as sweat sunlight fastness, wet rubbing fastness, and the light fastness of azo red dyes and azo blue dyes

(4) there are few dark varieties that can replace vulcanized compounds and reduced dyes