The pre-dyeing stage includes a series of operations that prepare the textile product for subsequent finishing treatments such as dyeing, printing and finishing.
These operations vary according to the type of fibre on which they have to be carried out, to the structure of the textile product (staple, top, sliver, yarn, fabric) and also depend on the subsequent treatments to be carried out, which may change according to various factors such as market demands, customer requirements, staff experience, and availability of machines.
The pre-dyeing stage includes for example desizing, singeing, mercerising, scouring, and bleaching. Each process varies according to the processing conditions and the above-mentioned specific situations.
Some of these processes (for example bleaching and mercerising) can be considered either preliminary operations or finishing treatments; this depends on the type of the downstream processes to be carried out on yarns or fabrics.