Conventional bleaching of textiles is carried out at high process temperatures and requires considerable amounts of water, wastewater, and energy, as well as the addition of alkali to activate the required hydrogen peroxide.
German company Zschimmer & Schwarz developed a new process for bleaching that claims to provide both ecological and economic efficiency. Their bleaching process is named ‘COLD WHITE’ and is claimed to enable powerful bleaching at temperatures below 80°C, resulting in savings of energy and time, a lower carbon dioxide emission and decreased wastewater pollution.
Additionally, the milder bleaching conditions apparently lead to lower degreasing of the cotton. Further side effects are a smooth fabric passage in the jet machine and a much lower tendency to knot formation, the quantity of a crease preventing agent required for goods that tend to creasing can be reduced and the pilling propensity of the fabrics can be diminished as well. Bleaching at low temperatures also causes less damage to the cotton fibre (higher degree of polymerization). In short, low-temperature bleaching not only involves a responsible dealing with our environment, but also has a positive effect on economic aspects like high production safety, consistent quality and improved customer orientation.