The knitted fabric to be printed must also be pre-treated to remove cotton stains, impurities, grease, wax, etc., increase the whiteness of the fabric and improve the wetting and water absorption properties of the fabric, so as to achieve a good printing effect. Pretreatment processes can be divided into two categories, namely traditional alkali treatment and modern bio-enzyme treatment. Bio-enzyme treatment meets the requirements of environmental protection processing, but it is difficult to meet the requirements of fabrics with high whitening or bleaching requirements at present, so conventional alkali treatment processes are still widely used. It is very necessary to gradually cool down the water washing of spandex fabrics after pretreatment to prevent sudden cooling from causing fiber shrinkage and creases.
