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United States Department of Agriculture

Agricultural Research Service

Title: Statistical Parameters of Cotton Short Fibers

item Cui, Xiaoliang
item Thibodeaux, Devron
item Robert Jr, Kearny
item Calamari Jr, Timothy

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: February 1, 2004
Publication Date: June 1, 2004
Citation: Cui, X., Thibodeaux, D.P., Robert Jr, K.Q., Calamari Jr, T.A. 2004. Statistical parameters of cotton short fibers. In: Proceedings of the Beltwide Cotton Cotton Conference. p. 2383-2386.

Interpretive Summary: Short fiber content (SFC) is an important quality parameter of cotton. Cotton with low SFC can produce strong, fine, and uniform yarns, which increase the efficiency in textile processing because of less yarn breakage or ends-down. However, the measured SFC has very high variation and hence lack of accuracy and precision. Various statistical parameters of cotton fiber length distribution were studied in this reseach based on 21 samples of different varieties and growth areas. A new statistical parameter, Lower Half Mean Length (LHML) has very high correlation with the short fiber content, but only one third (1/3) of its variation. Therefore, the LHML becomes a good candidate to subsitute the SFC. In the U.S., the short fiber content is defined as the percentage of fibers shorter than 1/2-inch in length. However, the defining length in China is 16 mm for short stapel cotton and 20 mm for long staple cotton. The short fiber content values defined by different limiting lengths were studied in this research, and the results showed that they all well correlated with short fiber content defined by 0.5 inch, indicating the SFC currently used in the U.S. is a good indicator of short fibers in cotton. The correlation of the short fiber content with other length parameters was also studied, including two parameters used in the U.S. cotton classing system, namely, Upper Half Mean Length (UHML) and Uniformity INdex (UI). The study showed that the UI contains a significant amount of information about short fibers, but the UHML very little. The results enhanced our understanding of the relationships among the various statistical parameters of cotton short fibers, and hence benefit cotton research, cotton trade, and textile processing.

Technical Abstract: Various statistical parameters of cotton fiber length distributions were calculated from AFIS (Advanced Fiber Information System) test data on 21 cottons of different varieties and growth locations. The results show that the SFC (short fiber content) defined by 0.5 inches is a good indicator of short fibers in a sample based on the high correlation coefficients with short fiber content values defined by other lengths such as 0.4 or 0.6 inches. However, the measured short fiber content has very high variation, as high as 6.8 times the CV% of UHML (Upper Half Mean Length). The high variation of SFC is one of the major problems hindering its use in the cotton classing system. The LHML (Lower Half Mean Length)l a new indicator for short fibers in introduced in this study. The results show that the LHML has very strong correlation with SFC, but much lower variation, only 1/3 of the CV% (Coefficient Variance) of the SFC. Therefore the LHML is a very good candidate for indicating the short fiber content. The uniformity index that is used in the U.S. classing system correlates to the SFC, but the Upper Half Mean Length has very low correlation with the SFC.

Last Modified: 4/24/2014
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