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Abstract
SUMMARY This study has been dealt with the determination of color matching of cotton fabrics dyed with different classes of dyes namely: direct, reactive and vat dyes.For given a set of color matching, the fabrics were dyed by different dye shades. The extent of the coloration is given by both the dye classes and the mixture ratio of their different concentrations.The increase in the dye concentration leading to an increase of the color strength of the dyed materials which expressed as K/S value.
Each colored material has its own distance appearance based on the three elements: hue, value and chroma. By using these three attributes we can accurately identify a particular color and distinguish it from any other.Hue is how to perceive a color. Value describes its luminous intensity, that is, its degree of “lightness”.
Chroma is the vividness or dullness of a color. The assessment of color is an assessment of color match or color difference from a known standard. CIE L a b are attempt to be used for comparing the color of dyed samples with other colors of different dyes and their different concentrations.L*a*b* color space of the colored materials is expressed as a rectangular coordinate system L*a*b* color tolerancing lead to L*c*h* color tolerancing which is expressed as a cylindrical polar coordinate system.CMC tolerancing is a modification of CIELAB which is expressed as ellipse coordinate. CMC tolerancing provides better agreement between visual assessmentand instrumentally measured color difference. the collor difference for the rectangular coordinates are: ΔL*, Δa* and Δb*. The total color difference of the dyed materials is ΔE*ab.
The color difference for the cylindrical coordinates are: ΔL*, Δc* and Δh°
The total color difference of the dyed materials is ΔE*ch
CMC color difference (DECMC), a modification (transformation) of CIE L*c*h* color difference, has proven to be a useful measure of the commercial acceptability of colored products and for textile industry acceptability applications, CIE94 was used.
KL=2 KC=1 KH=1
SL=1 SC=1+0.045.C* SH= 1+0.015.CColour matching using computer in the textile garment industry helps it to obtain the more suitable choice of dyestuffs or mixtures for dyeing which give the right and required colors of textile garments with good fastness properties and saving in costs and time.