No.8（2013）21.Effect of cotton bleaching using ozone micro-bubbles

Ichiro Enomoto, Koji Takeda, Risa Nagao,Shin Soeda, Yukinori Hoshi, Yoshiro Takahashi, Ryoiti Shibuya, Fumi Masuko, Chizuru Mitani

  Cotton fabrics bleached using ozone micro bubbles were examined. Since the solubility of ozone in water improves in acid, the effect of adding an acid (acetic acid) to water, and the effect of adding an electrolyte (NaCl) to stabilize micro-bubbles were investigated; a low temperature and pH 6 with 45 g of electrolyte gave the best conditions, and 1 hour of bleaching a cotton fabric gave a whiteness of more than 85. The scale of the experiment was expanded based on these processing conditions, a 2.2 kW micro-bubble generator was used, and 1 kg of cotton fabric was processed. The same whiteness of more than 85 was achieved from 1 hour of ozone micro-bubble processing, just like the previous experiment. The ozone concentration at this time was about 11 mg/L, a high concentration. Degradation of the cotton fabric due to ozone oxidization was investigated, and tensile strength was found to be comparable to the original fabric, and no degradation due to the bleaching processing was seen. However, since a merit of using ozone is expected to be an antibacterial effect, we used coliform bacillus in an examination and after the ozone micro-bubbles process was implemented, none of the bacteria could be detected.

Keywords
Cotton fabrics, Bleaching, Whiteness, Ozone micro bubble

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