| Abstract: | The purpose of this study was to investigate the bleaching efficiency of activated sodium perborate at low washing temperatures and the resulting energy saving. The comparison of the washing efficiency of basic and activated detergent was based on practical washing tests. The types of dirt used were coffee, fruit juice, tea, blood and a soot-oil mixture. The washing temperatures were 50, 60, 70 and 80°C. The cleanness of the washing was determined by a whiteness measurement. The consumption of electrical energy was measured with a kWh-meter. The higher the temperature, the more effectively all the types of dirt were removed from the textiles. With activated detergent a cleanness was obtained at 50°C and 60°C that was almost as good as with basic detergent at 80°C. The coloured types of dirt washed out more easily than blood or the soot and oil mixture. An average saving of 20% in the consumption of energy was obtained when the washing temperature was lowered by 10°C. With activated detergent, 45% of the energy consumed using basic detergent was saved with no reduction in the final cleanness. |
