Mercerization is a treatment that is carried out on the cotton fabric under tension with caustic soda, concentrated at 30° Be (Baumè), at a temperature of 10/15°C. Cotton fabrics mixed with viscose rayon can also be mercerized, for which the most suitable parameters are 13° Be and a bath temperature of approximately 20°C. Due to the high tension that can be exerted on the fabric, the chain machine is the most suitable for carrying out mercerization with a high degree of brilliance, but for greater compactness
and yield, cylinder machines are usually used. However, these are fully automated machines, so the piece, after rinsing, comes out mercerized and ready for subsequent processing. Due to the difficulty of soda penetration, it is necessary to use wetting substances.
For knitted fabrics, given the particular structure of the fabric, the machine is equipped with motorized cylinders which prevent excessive stress on the fabric.