Ozonation: a Green Source for Oxidized Cotton

Abstract

Research was carried out on the oxidation of cellulose by ozone treatment. It is considered as environment friendly in comparison with the existing oxidation methods used in industry for a long time. This treatment is used in different applications such as the scouring / bleaching of cotton fabrics and in improving the properties of Kraft pulp cellulose in the paper industry. In this study, the effect of Ozone treatment on cotton yarn properties was investigated. This investigation can help in obtaining the maximum crystalline percentage of cotton for the production of nano-crystalline cellulose. Two-ply cotton ring spun yarn was treated with ozone gas for different time periods. Yarn tensile properties, wickability, the copper number and physical appearance were observed. It is evident that yarn tensile properties deteriorate drastically after a certain time, while the wickability and copper number increase simultaneously. n Material and method In this study, cotton fibres (Medium Sta ple Pakistan Cotton) with average values of 28 mm staple length and 1.65 dtex (fi bre linear density) were used to produce 25.5 tex ring spun yarns with 711 t.p.m. (Z twist). Afterwards these single yarns were folded and twisted to produce twoply yarn with 364 t.p.m. (S twist). 8 yarn samples, 0.5 grams each, were mounted separately on special stainless steel holders and kept in closed containers filled with the ozone gas. The setting of the ozone generator - „TRIOTECH GO 5LAB-K” (Czech Republic) was kept same for all samples: 1.5 minutes for the ozone charging time, and 4.5 mg/litres of ozone gas. The samples were kept in their containers for different time periods and then taken out according to the plan shown in Table 1.