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additional information about this research in Agricultural Research. Wool and Cotton Can Now Dye
TogetherBy Tara
Weaver-Missick November 9, 2000A process to make cotton more
chemically similar to wool so the two fibers can be combined into an easily
dyed fabric blend has been developed by Agricultural Research Service chemists. Scientists at ARS Eastern Regional
Research Center in Wyndmoor, Pa., developed the new single-bath dyeing
procedure, called union dyeing, for wool/cotton blends. Normally, when wool and
cotton are blended together, two separate dye baths are required. Before the new process was developed, dyeing a cotton/wool blend was
difficult because the two fibers have different chemical makeups, leading to
uneven coloring. Wool takes up most of the dye, while the cotton is left mostly
undyed. ARS simple approach is to reverse the chemical charge of cotton from
negative to positive before dyeing so that both fabrics are positively charged.
Wool is already positive. The scientists use positively charged compounds
called cationic fixatives, which are typically applied after cotton is dyed to
help it retain color. Since the dye is negatively charged and opposites attract, the cotton and
wool dye to a uniform shade because the dye is attracted equally to both
fibers. This one-step union-dyeing process can be done with one dye, in one
bath, under one set of conditions. Experimental textile treatments like this one may broaden the market for
cool-weather garments made of wool and cotton blends. This technology could cut
textile dyeing costs, savings that can be passed to consumers seeking versatile
garments for both the spring and fall months. Additional information about this research is available in the November
issue of ARS' Agricultural
Research magazine. ARS is the chief scientific research agency of the
U.S. Department of Agriculture. Scientific contacts: William N. Marmer and Jeanette M. Cardamone,
Hides, Lipids and Wool Research Unit, ARS Eastern Regional Research Center,
Wyndmoor, Pa.; phone (215) 233- 6585 [Marmer], (215) 233-6680 [Cardamone]; fax
(215) 233-6795; [email protected],
[email protected]. U.S. Department of Agriculture |