Abstract
As today's washing machines have large capacities, rather thick items are now washed more than before. With this, the washing effects of the under side of thick items or fabrics lying one on top of another have become more important. However, the washing of inside surfaces has been little investigated to date. In this paper, methods of evaluating inside detergency of detergents or washing machines were investigated and a convenient one was proposed. Using that method, washing experiments were carried out, resulting in a number of interesting findings. Soap had the least inside detergency at low washing temperature and the largest at high washing temperature. Synthetic detergent A containing enzyme had the largest inside detergency at about 50 °C and, on average, it was significantly larger than any other detergents at each temperature. Light duty detergents B and C depended little on washing temperature. The effect of water pressure on inside detergency was greater for synthetic detergents A, B, and C than it was on ordinary detergency and the inside detergency depended little on detergents or washing temperature, while that of soap depended on washing temperature considerably. A statistical analysis was done on detergency. The washing machine and washing temperature contributed 30% to 50% on ordinary detergency with all detergents. However, the inside detergency of soap and that of synthetic detergents A, B and C were very different. The effectiveness of soap was 77% dependent on the washing temperature, while that of synthetic detergents A, B and C depended on the washing machine at the rate of 55%, 83% and 67% respectively.
