Theme: digital textile

Chemical auxiliaries used for dyeing

Depending on the type of fibers, various additives are used to improve the dyeing process. In the case of cellulose fibers, where the baths take place in an alkaline environment, it is crucial to maintain the suitable pH of the bath. The most commonly used for this purpose is soda lye, i.e. an aqueous solution of sodium hydroxide (caustic soda).

Other additives used in the process of dyeing cellulose fibers are oxidizing agents (most often hydrogen peroxide is used here) and detergents that provide an effective course of the washing operation after dyeing. The Roksol series (PSWN, ICESOLDE PAN / 35L and AZR) is a group of effective washing and cleaning agents. These products can be used as agents for industrial washing of textile products. They dissolve very well in water and improve the effectiveness of dyeing through their penetrating properties. Roksol products allow the removal of a number of substances, such as natural fats, lubricants, synthetic waxes and sizing. Thanks to their low-foaming properties, they can be used in many technological processes on various types of apparatus without causing disturbances in their work.

In the case of wool fibers, where the dyeing process takes place in an acidic environment, sulfuric acid or acetic acid is used to provide a suitable pH for the bath. In addition, reducing agents (e.g., sodium thiosulphate) and leveling agents are also added to the solution, which are used to obtain uniform dyes.

In dyeing of synthetic fibers, a number of additives are also used. PES (polyester) fibers require the use of thickeners (e.g. polyacrylates) to limit dye migration during drying. PA (polyamide) fibers require strict pH control and for this purpose sulfuric or acetic acid is used. In addition, a number of levelling and dispersing agents are also used. The PCC Group offers a number of specialized products that can perform this function. The NNOC E dispersant is a product used in dyeing processes as a dispersing and equalising agent. It maintains sparingly soluble dyes in a homogeneous dispersion in colouring baths.