STUDIES ON CYSTINE IN WOOL: (IV) IMPROVEMENTS ON SETTING PROCESS BY USING MERCAPTO ACID

It is well known that the crabbing is a process to set wool fabrics in weak basic aqueous soltion, but on pre-dyed fabrics acidic dyes are desorped through this treatment. So, authors tried to set the worsted fabrics on acidic side by using mercapto acid solution named “Cold Set Solution”. Results obtained are as follows. 1) Although the bath temperature of thioglycollic acid (T. G. A.) treatment was lower than the case of crabbing, T. G. A, treatment set plainly the wool fabrics under tension. On severe conditions this treatment gave the setting effect for fabric texture but anti-shrinkability was lowered, Rinsing and hydrogen peroxide treatment after the reduction treatment promoted the anti-shrinkability. The wool fabrics treated alone in T. G. A. solution had higher anti-shrinkability than those treated in basic T. G. solution, but this order was reversed by hydrogen peroxide treatments respectively after reducing. The necessary quantity of T. G. A. into wool to set was about 10mg equivalents/100g wool. 2) when the wools reduced on acidic and basic sides showed the same alkali-solubility, the former contained more quantity of T. G. A, than the latter. Other anionic ions in T, G. A. bath decreased the adsorption of T. G. A. by wool, but those in basic T. G. bath gave little effects. Hydrogen peroxide acted more effectively for the wool reduced with T. G. in basic solution than in acidic, while the rinsing was effective for the wool reduced in reduced in acidic. Therefore, it seems that the rinsing effect is caused by the desorption rather than by the oxidation of T. G. A. contained excessively in the reduced wool. From the facts mentioned above, some differences in mechanism between acidic T. G. A. and basic T. G. treatments on wool was noted.