Desizing of Cotton fabrics

Desizing is the process of removal of size material applied on warp threads of a fabric to facilitate the process of weaving. Size forms a stiff, hard and smooth coating on warp yarns to enable them to withstand the cyclic tensions during weaving and reduce breakage. Desizing is an essential stage of all textile processing, in which ‘size’ is removed from fabric before completing the pre-treatment process, which is necessary before dyeing, printing and finishing.

Where does the size come from?

Before yarn is woven into fabric, the ‘Warp’ yarns are coated with sizing agents. This strengthens the yarn (decreasing breakages on the loom), reduces friction and improves productivity.

However the sizing agents often resist the dyes and chemicals commonly used in textile processing, so they have to be thoroughly removed before any wet processing can take place.

Most sizing agents (particularly for cotton yarns) are starch-based, for reasons of economy and weaving performance.