What is the Alkaline problem during finishing process?

The pre-treatment of cotton fabrics usually needs to be treated with a higher concentration of alkali to remove fabric impurities (especially with a larger amount of mercerizing alkali). It is not easy to wash the alkali into the fiber. When dyeing (reactive dyes ,vat dyes), alkali should also be added. The cloth surface may be alkaline during finishing. 

The chemical fiber fabrics must undergo reduction cleaning after dyeing. At present, printing and dyeing factories are still using sodium hydroxide and caustic soda for cleaning. If the subsequent cleaning is not clean, it will also cause alkali on the cloth surface before softening. Ordinary silicone oil is not alkali resistant and will break under alkaline conditions. This is the reason why the factory sticks to the roll after passing several kilometers when it is soft. Therefore, the cloth surface must be cleaned with alkaline agent or added with acetic acid in the working fluid before softening to maintain the PH5-6 of the rolling tank.