PART II. STUDY REGARDING THE INFLUENCE OF BIOSCOURING TREATMENT ON 60 % COTTON + 40 % COTTONISED FLAX MATERIALS FOLLOWED BY A WHITENING TREATMENT USING ALTERNATIVE METHODS

Abstract

A comparative study of whitening treatment using various methods for 60 % cotton +40 % flax materials was made. The samples materials were scoured by bioscouring treatment in ultrasound as was described in our previous work (part I). The removal of noncellulosic impurities using the bioscouring treatment was evaluated by weight loss and hydrophilicity of the treated samples. Some of these bio-scoured samples were further bleached using the folowing procedures: Classical procedure with hydrogen peroxide (30 %), bleaching with catalyst and with laccase enzyme. Hydrogen peroxide is usually used as oxidative bleaching agent for cotton and cotton blends. A high and stable degree of whiteness is obtained by this treatment. The advantages of the treatment are: low costs, flexibility of application and the possibility of a one-bath (scour/bleach) procedure. But, high temperature of bleaching under alkaline conditions necessitates high energy utilization that can cause considerable fiber damage. Different solutions like the use of enzymes and catalysts have been investigated to overcome such problems. In order to characterize the quality of the enzymatic pretreatment compared to the classical one, the values of the whiteness degree after different type of bleaching (hydrogen peroxide, catalyst and laccase) for the samples treated with the same concentration of enzyme were studied. The tensile strength and elongation at break of treated materials were investigated.

Keywords

• Cotton
• flax
• Bioscouring treatment with ultrasound
• Weight loss
• Alternative whitening methods
• whiteness degree