STUDY REGARDING THE INFLUENCE OF THE BIOSCOURING TREATMENT IN ULTRASOUND ON 60 % COTTON + 40 % HEMP MATERIALS PART II. STUDY REGARDING THE INFLUENCE OF BIOSCOURI NG TREATMENT FOLLOWED BY A WHITENING TREATMENT USING VARIOUS METHODS

Abstract

This study shows a comparative characterization of whitening treatment using various processes for 60 % cotton +40 % hemp materials scoured by Bioscouring treatment in ultrasound described in our previous work. The results of the extraction of noncellulosic impurities using the Bioscouring treatment was ex pressed as weight loss, hydrophilicity. Some of these bio-scoured samples were whitened using various procedures: Classical procedure with hydrogen peroxide (30%), with catalyst and with laccase enzyme. By whitening procedure, the double bonds from chromophore groups of natural pigments from cotton and hemp are destroyed by oxidation reactions, the Π electrons being those responsible for the yellow color of the fabrics. In order to characterize the quality of the enzymatic pretreatment compared to the classical one, the values of the degree of white were studied after different type of bleaching (hydrogen peroxide, catalyst and laccase) for the samples treated with the same concentration of enzyme SERA ZYME C-PE (ROGLYR ECO 183) - Pectate Lyase. For comparing the degradation occurred during the enzymatic preatreatment of cellulosic fabrics, before and after bleaching with enzymes, catalyst and classical method, measurements of the tensile strength and elongation at break for the treated 60 % cotton +40 % hemp material, were performed.

Keywords

• cotton
• hemp
• bioscouring tretment with ultrsound
• weight loss
• whitening
• whiteness degree