Sulfur black dyes are sulfur-containing macromolecular compounds that contain disulfide bonds and polysulfide bonds in their structures and are very unstable. In particular, the polysulfide bonds can be oxidized by the oxygen in the air to sulfur oxides under certain temperature and humidity conditions, and further react with the water molecules in the air to produce sulfuric acid, thereby reducing the strength of the yarns, causing the fibers to be brittle and serious. When the fibers are all embrittled into powder.
For the purpose of reducing or preventing fiber brittleness after dyeing with a vulcanized black dye, the following points must be noted:
1. The amount of sulfur black dye should be limited, and the amount of mercerized dye should not exceed 700g/bag. Because of the high amount of dye, there is a large chance of brittleness, and at the same time, the color fastness is reduced and the water washing is also more difficult.
2, after dyeing should be fully washed, to prevent water washing is not clean, the floating color yarn easily decomposed into sulfuric acid during storage and make the fiber brittle.
3, after dyeing must use urea, soda ash, sodium acetate and other anti-brittle treatment.
4. Before dyeing the yarn, simmer with clean water. The embrittlement of the dyed yarn after rinsing with the test water is better than that with lye.
5. After dyeing, the yarn should be dried in a timely manner, because the wet yarn is prone to heat during the stacking process, so that the content of the yarn anti-brittle agent is reduced, the pH value is lowered, and it is not good for preventing brittleness. After the yarn is dried, it should be cooled naturally, and the temperature of the yarn can be packaged after it has cooled down to room temperature. Because it is not cooled after being dried, it is packaged immediately, the heat is not easy to disperse, and the decomposition of acid by the dye increases the energy, and the possibility of brittleness of the fiber becomes greater.
6. Anti-brittle sulfur black dyes are used. Such dyes have been added with formaldehyde and chloroacetic acid during the production process. The resulting A-chlor type sulfur-proof and anti-brittle black makes the easily oxidized sulfur atoms a stable structural state. Sulfur atoms are prevented from oxidizing to generate acid and the fibers are brittle.
For more content, please follow this site
Biconcave Lenses
Professional Biconcave Lenses manufacturer is located in China, including Biconvex Lenses,Achromatic Lenses,Concave Lenses, etc.Founded in 2014, Bena was co-founded by several experienced engineers who have more than 10 years of optical design, process, production and test. We provide customization service for high precision (rms = 1/100λ, λ=632.8nm), large diameter plane mirror (>500mm) and aspherical lens, as well as professional spherical lens (such as Optical Domes with diameter 280mm), involving different materials including K9, Silicon, Sapphire, SiC, glass ceramics, fused silica, and other various optical glasses, and we can also deal with the nickel-phosphorus alloy surface on different substrates.
Biconcave Lenses,Biconvex Lenses,Achromatic Lenses,Concave Lenses
Changchun Bena Optical Products Co., Ltd , https://www.benaoptic.com
