On washing of a cotton fabrics treated with caustic soda, the effects of temperature, stirring conditions fabric thickness were experimentally studied. These experimental results were also theoretically analyzed the diffusion equation of the fabric (or yarn) model assuming the homogeneous substances .
Up to the present, some studies have concluded that washing results not always coincide with theoretical equation assuming the diffusion theory. However the experimental values agreed well with the theoretical results in this report. The reasons were discussed why the experimental results of traditional studies did not coincide with theoretical values. It was concluded that, when the diffusion coefficent of washed material in fibers differs from that in water, the difference between experimental and theoretical results have occured.
On the basis of this study, the following theoretical equation were proposed :
C=T
1e
-αt+ T
2e
-βtwhere, C : mean concentration of washed material in a fabric,
t : washing time,
T
1, T
2α, β : constans which depend on initial values, diffusion coefficient, fabric properties and washing conditions.
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