Tendering of cotton

Recent approaches directed toward preventing oxidation of cotton cloth included using accelerated aging of alkaline-treated cotton cloth for neutralization of acidic, oxidized, cellulose decomposition components that in cellulosic textiles and in paper are responsible for age tendering and yellowing. Conclusions regarding the relative effectiveness of treatments at room temperature were based on results of treatments at one elevated temperature (8). Predictions of long-term effects of these treatments are unknown (9). 

Zimmerman, C. L., Some Studies of the Tendering of Sulfur Black Dyed Cotton, M. S. thesis,... 

Chlorine retention n. A characteristic of several resins and textile finishes whereby they retain some of the chlorine from bleach. On heating of the goods, the chlorine forms hydrochloric acid, causing tendering of the cloth. This is especially true of certain wrinkle resistant finishes for cotton and rayon. 

Tendering Effects. CeUulosic materials dyed with sulfur black have been known to suffer degradation by acid tendering when stored under moist warm conditions. This effect may result from the Hberation of small quantities of sulfuric acid which occurs when some of the polysulfide links of the sulfur dye are mptured. A buffer, such as sodium acetate, or a dilute alkaH in the final rinse, especially after oxidation in acidic conditions, may prevent this occurrence. Copper salts should never be used with sulfur black dyes because they cataly2e sulfuric acid generation. Few instances of tendering with sulfur dyes other than black occur and the problem is largely confined to cotton. 

Many substances wiU prevent the growth of mildew. Zinc, copper, and mercury salts, phenols, chlorophenols, and phenylphenols have been used. Zinc chloride is very effective and was used extensively in the past, but it was not without objections, such as a tendency to cause tendering, particai-larly during singeing. The British Cotton Industry Research Association found that salicylanUide ... 

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