sulphur black 240% is a high molecular compound containing more sulfur, its structure contains disulfide bonds and polysulfide bonds, and it is very unstable. In particular, the polysulfide bond can be oxidized to sulfur oxide by oxygen in the air under certain temperature and humidity conditions, and further interact with water molecules in the air to generate sulfuric acid, thus reducing the strength of the yarn, fiber brittleness, and all fibers are embrittle into powder when serious. For this reason, in order to reduce or prevent fiber brittleness damage after dyeing with vulcanized black dye, the following points must be noted:
① The amount of vulcanized black dye should be limited, and the amount of mercerized special color dye should not exceed 700g/ package. Because the amount of dye is high, the chance of brittleness is large, and the dyeing fastness is reduced, and the washing is more difficult.
② After dyeing, it should be fully washed to prevent unclean washing, and the floating color on the yarn is easy to decompose into sulfuric acid during storage, which makes the fiber brittle.
③ After dyeing, urea, soda ash and sodium acetate must be used for anti-brittleness treatment.
④ The yarn is boiled in clean water before dyeing, and the embrittlement degree of yarn dyed in clean water is better than that of lye after dyeing.
⑤ The yarn should be dried in time after dyeing, because the wet yarn is easy to heat in the pile process, so that the content of yarn anti-brittleness agent is reduced, the pH value is reduced, which is not conducive to anti-brittleness. After drying the yarn, it should be cooled naturally, so that the temperature of the yarn can be packaged before falling to room temperature. Because it is not cooled after drying and immediately packed, the heat is not easy to distribute, which increases the energy for the decomposition of the dye and the acid, causing the possibility of the fiber to be brittle.
⑥The selection of anti-brittle-sulphur black dyes, such dyes have been added to formaldehyde and chloroacetic acid when manufacturing, the resulting methyl-chlorine vulcanized anti-brittle-black, so that the easily oxidized sulfur atoms become a stable structural state, which can prevent the oxidation of sulfur atoms to generate acid and brittle fiber.
Post time: Jan-22-2024