Effects of Laundering on
the Colorfast Properties of
Reactive- and Direct-Dyed Cotton Fibers
Melanie Doyal and Mary Warnock1
RESEARCH PROBLEM
Arkansas always has been a cotton-producing state. It now ranks fifth in the United
States with most of the cotton fibers being used in ready-to-wear clothing (Kadolph et
al., 1993). One of the greatest problems facing the garment industry is the colorfastness
of dyed cotton fibers. If the consumer is to continue purchasing cotton wearing apparel,
the dyes must be colorfast. Knowing that reactive dyes were specifically developed for
cotton fibers, and that direct dyes also can be used with cotton fibers, the question then
became: which dye would be the most colorfast following laundering and which would
be the best choice for the garment industry when dyeing cotton fibers?
BACKGROUND INFORMATION
Fiber-reactive dyes provide clear, bright shades, have good fastness properties,
allow versatility in application methods and contain lower substantivity levels than do
direct dyes (Mansfield, 1983; Aspland, 1992). The higher emphasis on reactive dyes
reflects the U.S. consumer’s interest in bright, high-fastness fashion shades in cotton
fibers. Currently, nearly one-third of the money spent on dyes for cellulose in the U.S.
is spent on reactive dyes. Reasons for this include the high consumption of cotton, consumer demand for bright colors, and the higher degree of colorfastness. The question of
comparing reactive dyes with vat dyes as to which class is better in terms of colorfastness was addressed by Stetson in 1973 (Stetson, 1973). No comparative analyses have
been done between reactive and direct dyes. This study addressed that issue in trying
to determine the effects of laundering on reactive- and direct-dyed cotton fibers.
Undergraduate honor student and professor, respectively, School of Human Enviromental Sciences,
Fayetteville.
1
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AAES Research Series 543
RESEARCH DESCRIPTION
The Deltapine 50 cotton cultivar (Gossypium hirsutum L.) was used for experimental purposes. Fibers were scoured and carded before dyeing with either the Procion
Red MX 305 reactive dye or the Diazol C 380 Basic Red direct dye. Both dyes matched
Cotton Corporation’s Fall/Winter 2004/2005 color card in the “wildflower” category.
An Ahiba Texomat G VI B dyeing machine (Ahiba, Inc., Charlotte, N.C.) was used to
dye the experimental fibers. Colorimeter values (L, a, b) were determined after dyeing
and following 1, 2, and 3 accelerated launderings in an Atlas Launder-ometer (Atlas
Electric Devices Co., Chicago, Ill.). The L, a, b data were analyzed as a split-plot design
in which the whole-plot structure was a completely randomized, two factor factorial
(fiber type x dye type) and the split-plot factor was number of launderings. Means were
separated using a protected LSD at = 0.05.
RESULTS AND DISCUSSION
Figure 1 exhibits the mean L, a, b colorimeter values as related to dyeing and
laundering. Laundering did make a difference on the reactive- and direct-dyed cotton
fibers in that color was lost following each laundering period. On the whole, the reactive dye produced a lighter colored cotton fiber than did the direct dye. This result is
supported by the higher mean values as shown in Figure 1. No matter the dye type, the
cotton fibers were not colorfast.
PRACTICAL APPLICATION
Knowing the colorfastness properties of these particular cotton fibers is an indication to the clothing industry as to their apparel utilization. This study has proven
that Procion Red MX 305 reactive dye resulted in a lighter dyed-cotton fiber than did
the Diazol C 388 Basic Red direct dye. Depending on the desired coloration of the end
product, clothing manufacturers now have choices between dye types, even though the
direct dye, like the reactive dye, was not specifically created for dyeing cotton fibers.
Dye choices made by the clothing industry will enhance the variety of dyed products
available for consumer consumption.
LITERATURE CITED
Aspland, J.R. 1992. Reactive dyes and their application. Textile Chemist and Colorist, 24:31-36.
Kadolph, S.J., A.L. Langford, N. Hollen and J. Saddler. 1993. Textiles. 7th ed. New
York, N.Y.: MacMillan Publishing Company.
Mansfield, R.G. 1983. Fiber reactives: Brightest lights on the dye marquee. Textile
World, 133:93-94.
Stetson, R. 1972. Polychromatic dyeing and fiber reactive dyes. American Dyestuff
Reporter, 61:42.
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Summaries of Arkansas Cotton Research 2005
Fig. 1. The mean colorimeter values of dyed and laundered 100% cotton fiber.
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