Project Database

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, to achieve the designed finishing. 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. Hong Kong Productivity Council (HKPC) has gained good experience in electrolytic technology for the textile dyeing and finishing industry through the previous ITF projects on development of electrolytic dyeing reduction and electrolytic bleaching which are similar technologies to this project


Machinery and Machine Tools Design Certificate of Merit in the 2012 Hong Kong Awards for Industries (2012)
Project No. (ITC) GHP/058/08TP
Project Type Platform
Project Co-ordinator Dr. MO Sam
Research Institute Hong Kong Productivity Council
ITF Amount HK$ 1,796,000
Start Date DD/MM/YY 2009-08-01
Completion Date DD/MM/YY 2011-07-31
AIE Holdings Limited
Crystal Knitters Limited
Link Dyeing Works Ltd
Tai Kung Weaving (HK) Factory Limited
TAL Apparel Limited
IP Number