What matters should be paid attention to when acid dyes are fixed?

Nowadays, acid dyes have been widely used in the dyeing of fabrics and are often used by people. However, the dyes usually have poor color fastness. Therefore, some users are fixing the dyes to meet the standard, but we need to pay attention to When the dye is fixing the color, the things to know, let's take a look!

Applicable technical guide: used for dyeing nylon fibers with acid dyes, and then processing the dyed products. After dyeing nylon fibers with acid dyes, the dyed product can be treated with NBS to improve its wet fastness, especially to water, sea water, washing, and sweat. The fastness can be significantly improved. Similar to all such additives, The degree of improvement in fastness varies depending on the dyeing method and fiber.

Concentration of acid dye: 1.0-2.0% (owf) NBS (calculated based on cloth weight) After dyeing nylon fiber with TELONL, SUPRANOL or other selected acid dyes, wash it with soft water, and then dye the dyed product with NBS at PH4.5, 70-80℃, 20-30 minutes, post-treatment.

Note: If you increase the amount of NBS by one third, you can also use hot air to complete the fixation operation. The wet fastness has been improved to a considerable extent, but the temperature should not exceed 180-185℃. If the temperature exceeds, or treatment with saturated steam, it will affect the NBS. When dissolving or diluting NBS, it is necessary to prevent direct contact with concentrated acetic acid. The contact of NBS with concentrated acetic acid will cause precipitation. Any precipitation that has occurred can be easily dissolved by adding a small amount of ammonia.

The presence of non-ionic additives in the post-treatment will cause precipitation and damage the NBS effect (the soap can be washed before fixing to prevent abnormalities). If the dyed material is coated with PU or covered with a film in the post process, do not use NBS for fixing treatment, otherwise it will affect its sticking effect. Nylon batt is treated with NBS and has a coarser feel, which will affect the subsequent textile operations. Therefore, for this kind of dyeing, only dyes with better wet fastness are selected for dyeing, and no fixation treatment is performed.