Central Glass Co Ltd and the National Institute of Industrial Science & Technology (AIST) of Kansai (Japan) had jointly developed technology to produce recyclable coloured glass. The newly introduced technology involves the coloration of glasses by photo-irradiation (ultraviolet or X-rays) and decolouration by heat treatment. By applying this technology, glass manufacturers can overcome the difficulties of recycling coloured glasses, thereby increasing glass recycling rates. There are several features inherent in the new technology. Glass products coloured by this method will not have the problem of surface hardness, which often must be solved when polymer-coating method is used. Products could also retain their shapes when they undergo decolouration. The technology is also free from the problem of pollution caused by vaporised organic compounds.
