Development of a Novel Electrolytic Ozone Spray Process to Achieve Aged-look Effect for Denim Wear

Over 70% fashioned denim wear need to go through a partial bleaching process to achieve aged-look or antique finishing effect. Traditionally, this has to be done by treatment with an oxidizing agent, potassium permanganate.

As potassium permanganate forms an insoluble manganese dioxide which needs to be cleaned by an aqueous reducing agent such as oxalic acid, this treatment step generates large amount of waste water and chemicals which creates environmental problems and hazards to the workers.

It is proposed to develop an electrolytic ozone spraying system for conducting the bleaching process. Ozone is a powerful oxidizing agent. The reaction of ozone with indigo dye in an aqueous medium can achieve a significant bleaching effect. The advantage of ozonation over the other oxidants is that it is a self-decomposed chemical. During processing, ozone converts the dye stuff into carbon dioxide and water, any residual ozone in the system will be decomposed into oxygen due to its instable nature.

Project Name (ITF)
Development of a Novel Electrolytic Ozone Spray Process to Achieve Aged-look Effect for Denim Wear
Project Number (ITF)
GHP/058/08TP