Abstract
A drum-type washing machine washes more effectively and consumes less water than the other type washing machines. We need to find the most effective washing conditions to increase the rinsing performance with the reduced amount of rinsing liquid in the drum-type washing machine. In order to determine the most effective washing conditions on the rinsing performance, we have considerd the following factors: main-washing liquid ratio, spin-drying time, spin speed during spin-drying, rinsing liquid ratio, number of rinses, rinsing time, and load of fabric. We also compared the rinsing performance between a controlled wash cycle of the drum-type washing machine and a standard wash cycle of a commercial pulsator-type washing machine. We measured the electrical conductivity of the liquid which was extracted from the fabric after the main-wash and each number of rinse. Increasing the number of rinses was the most important factor in increasing the rinsing performance. Then the rinsing liquor ratio, the main-washing liquid ratio, the load of the fabric, and the spin speed during spin-drying had a decreasing effect on the rinsing performance in that order. In our research the rinsing time and the spin-drying time did not show meaningful difference. The rinsing performance of the drum-type washing machine with a lower rinsing liquor ratio could be the same as or better than that of the pulsator-type washing machine because of the lager drum radius and a much higher spin speed.
