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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Cotton Structure and Quality Research » Research » Publications at this Location » Publication #345776

Research Project: Improved Quality Assessments of Cotton from Fiber to Final Products

Location: Cotton Structure and Quality Research

Title: Approaches to quantitating the results of differentially dyed cottons

item Peralta, Donna
item THIBODEAUX, DEVRON - Fiber Physics
item Delhom, Christopher - Chris
item RODGERS, III, JAMES - Retired ARS Employee
item Boykin, Deborah

Submitted to: Textile Research Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2018
Publication Date: 4/20/2018
Citation: Peralta, D.V., Thibodeaux, D.P., Delhom, C.D., Rodgers, J.E., Boykin, D. 2018. Approaches to quantitating the results of differentially dyed cottons. Textile Research Journal. 0(00):1-11.

Interpretive Summary: The differential dyeing (DD) process is a fiber dyeing technique used by the textile industry to visually judge the immaturity of cotton fibers, which can cause processing and dyeing difficulties. Micronaire is a cotton industry measurement for maturity and fineness of cotton fiber. The DD method is largely discretionary, so an attempt has been made to quantitate its results using a computer scanner's RGB (red, blue, green) color measurements. Traditional color measurements L*a*b* were compared to the RGB results. It was found that the G (green) and a* color measurements were found to have good correlations with the maturity measurement for cotton.

Technical Abstract: The differential dyeing (DD) method has served as a subjective method for visually determining immature cotton fibers. In an attempt to quantitate the results of the differential dyeing method, and thus offer an efficient means of elucidating cotton maturity without visual discretion, image analysis of cotton color images obtained via a scanner was performed and compared to spectrophotometrically measured color values. Low, Medium and High micronaire (Mic) cotton standards were differentially dyed, and it was determined that blending the dyed cotton was ideal for more precise color measurement; with the mean Red, Green and Blue (RGB) values for a Low Mic sample being 101.6 ± 23.9, 83.1 ± 22.0, and 98.3 ± 23.1, respectively while the same sample blended yielded RGB values of, 121.6 ± 9.0, 98.8 ± 8.6, and 116.0 ± 8.9 respectively. Comparing RGB values to sample Mic, it was found that the R and B color parameters do not show a trend with Mic, but the G values decreases with increasing Mic, indicating a decrease in green dye uptake with an increase in maturity. The conventional L*a*b* color space values were also obtained for the dyed cottons and compared to the RGB and Mic results. The % CV for the a* values are higher compared to the L* and b* measurements: ~31.9 %, 18.9 % and 8.6 % for Low, Medium and High Mic samples, respectively. L* and b* decrease with Mic, whereas the value of a* increases with Mic, indicating an increase in red dye with an increase in cotton maturity. The DD Bath method was found to be reliable, with R showing the greatest variances. The G and a* values obtained were found to be the best correlation of differences in Mic.