| 摘要 |
<p>The invention relates to a procedure of bleaching flax fibres with the help of ultrasound energy. The proposed procedure is based on peroxide (H2O2) bleaching in alkaline medium, applied to alkali- and enzyme pre-treated flax fibres. The advantage of the bleaching procedure by using ultrasound energy lies in its effect on the increased degree of whiteness according to CIE for 5,3 units in the case of alkaline and for 3,8 units in the case of enzyme pre-treatment, as well as in brightness (L*) of samples. The acting of ultrasound in a bleaching bath increases also the removal of impurities and incrusts and water retention ability (WRA), which is an important goal of all procedures for pre-treatment and bleaching of materials based on natural fibre-forming polymers. The acting of ultrasound in the bleaching process, however, does not affect significantly the reduction of degree of polymerisation and thus the loss of physico- mechanical properties.</p> |
