アルカリ脱脂液での脱脂過程の解析 [in Japanese] Analysis of Process on Alkali Degreasing [in Japanese]
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Surfactants greatly influence degreasing velocity. To explain the differences due to surfactant type, we analyzed the remaining oil film thickness (<i>T</i>) and the emulsion characteristics induced by the surfactants involved It became clear that <i>T</i> had a strong relationship to the average oil globule diameter <i>r</i><sub>∞</sub> in the oil emulsion, which had been formed at a low concentration. <i>T</i> and (<i>dT/dt</i>)are summarized as follows: T=r<sub>∞</sub>;/R, dT/dt<sub>(initial)</sub>=-C<sub>1</sub>*r<sub>a</sub>(T-r<sub>∞</sub>)/√r<sub>∞</sub>, dT/dt<sub>(end)</sub>=-C<sub>2</sub>*√r<sub>∞</sub>.<br><i>R</i>: Water wetting area ratio, <i>r</i><sub>a</sub>: Substantial oil globule diameter of highly concentrated emulsion in boundary film. The degreasing velocity (<i>dT/dt</i>) in all surfactants was decided by <i>r</i><sub>a</sub> and <i>r</i><sub>∞</sub> size. These sizes characteristically depended on the surfactant type and oil concentration. The ideal surfactant for high-speed degreasing, should therefore form an oil globule distribution at the smallest size<0.1 and <i>r</i><sub>∞</sub>=2, <i>r</i><sub>a</sub>>30μm.<br>Little possibility existed; however, that (<i>dT/dt</i>) was controllable by using the specific globule size alone, which had the slowest movement velocity, only when degreasing by the surfactant ABS, etc., had nearly been completed.
- Jitsumu Hyomen Gijutsu
Jitsumu Hyomen Gijutsu 49(2), 185-190, 1998-02-01
The Surface Finishing Society of Japan