Skyzol®Reactive Dyes

Reactive dyes are dyes that form a chemical bond with the fiber during the dyeing process. They are mainly used on cellulose fibers such as cotton, viscose, and linen, and some types can also be applied to wool and silk. Because the dye becomes part of the fiber structure, reactive dyes are valued for their bright shades, good wash fastness, and clean overall performance.

Reactive dyes perform best on cellulose fibers, especially cotton. They are also widely used on viscose, rayon, linen, and other regenerated or natural cellulosic materials. Certain reactive dye types can be used on protein fibers like wool and silk as well. In commercial textile processing, cotton and cotton-rich fabrics are usually the main application area.

Salt helps drive the dye from the dye bath onto the fiber by improving dye exhaustion. Alkali is used to activate the fiber and create the conditions needed for the dye to react and bond with it. In simple terms, salt helps move the dye onto the fabric, while alkali helps fix it there. Both are important for achieving good color yield and fixation.

Dye hydrolysis happens when part of the reactive dye reacts with water instead of the fiber. Once that happens, the dye can no longer form a bond with the fabric, so it becomes unfixed dye. This lowers fixation efficiency, increases dye loss, and makes afterwashing more difficult. In production, excessive hydrolysis can raise costs and create more wash-off and wastewater treatment pressure.

An effective wash-off process removes unfixed and hydrolyzed dye from the fabric surface after dyeing. This step is critical for improving wash fastness, reducing backstaining, and keeping shades clean and stable. Without proper wash-off, the finished fabric may show poor rubbing or washing performance, especially in deeper shades. This is also where suitable soaping agents and wash-off auxiliaries can make a clear difference.