Bio-washing of Pigment Dyed Denim with Laccases

Nowadays, pigment dyeing is one of the most interesting methods that is applied to make specific designs on denim and fashionable garments. Here, in this research, the bio-washing of pigment dyed denim has been considered with laccases. The desizing and bleaching of denim samples are first carried out and they are subsequently dyed with two types of pigments (Bemacol Blue GF and Ricoprint OSD Serie Blue) through the exhaustion method. The pigment dyed samples are then washed with various laccase concentrations, with and without the use of pumice stones. Color changes, bending and wrinkle recovery are examined. Furthermore, the surface morphology of the products is verified by a scanning electron microscope (SEM) and a Projectina microscope. The samples washed with laccases and pumice stones show higher dye stripping compared with those without the use of pumice stones. The bending properties of the samples treated by pumice stones show desirable results compared with the laccases, but this caused intense damage to the samples. Also, desirable results have been achieved by using laccases in the washing process. Treatment with laccases helps to obtain brilliant samples with decreased staining on the samples with a pocket and also lowers pigment discharge in the effluent.