Abstract
Washing experiments were performed by implementing different modes of action on a single sheet of artificially soiled cotton fabric : bending alone at one portion and a combination of bending and friction at another. The degrees of reflection at different portions were measured to separately evaluate the effects of bending and those of friction. A simple device was employed to measure the energy given to fabric sheets when they are bent at some curvatures. The energy data were used to assess the washing effects based on bending.
The results obtained were as follows.
1) In washing, the effects of friction appeared in a short period of time, but those of bending took more time to appear.
2) The effects of bending and friction were both approximately 30 percent of the entire washing effects.
3) The effects of bending increased monotonously with the curvature until it reached 0.2 (1/mm); and there was no increase any longer for greater curvatures.
4) The effects of bending were practically equal independent of positive and negative curvatures (front and reverse sides of the sheet).
5) The washing effects based on bending were practically proportional to the energy given to the sheet for a curvature of 0.2 (1/mm) or less.
