Effects of Cotton Fiber Blending and Processing on HVI Measurements—Part I

Abstract

To obtain a better understanding of the relationships between fiber properties of the constituents of a cotton blend and the processes up to drawing, a review is presented of the effects of blending, orienting, and removing crimp from fibers on HVI test results. These effects are also explored experimentally by testing fibers from the same laydown in bale, card sliver, and drawn sliver form using HVI equipment. Apparent reductions in upper half mean and increases in short fiber content of card sliver may be due to the formation of hooks. Significant correlations between micronaire and fiber properties related to length that are present in bale samples are lacking in both card and drawn sliver samples, suggesting that there is at least one unmeasured factor in this analysis. Measured micronaire values are sensitive to crimp and fiber packing density. Differences in fiber property distributions can have significant effects on HVI measurements, and distributions of single fiber properties of a blend may differ drastically from those of single bales. Strength tests of blended bundles may not include all constituents in the blend, because only the longest fibers are clamped in the jaws. Testing the fiber population at various stages of processing yields different information about fiber bundles.High volume instrument ( HvI ) systems provide abundant fiber property data that affect all phases of the cotton industry; the results are used by those who breed, grow, gin, classify, and spin cotton to control processes and improve product performance. Originally intended to evaluate fiber quality of individual cotton bales following ginning, HvI systems are increasingly used to characterize fiber properties after further processing. In this paper, we explore the effects of blending and processing cotton on fiber property distributions and Hvt test results, both theoretically and experimentally. We investigate further the effects of fiber property distributions on HvI bundle strength in Part II, along with the effects of bundle characteristics and jaw placement.Fiber Blending ELONGATION . Cui tested 25,000 fibers from each of two American Upland cotton samples on a Mantis. single fiber tester [ 3 ] . Using X 2 statistics, he determined that normal distributions fit single fiber elongations very well.Sasser et al. [ 16 ] developed a method for calctalatina bundle load-elongation curves by superimposing the constituent single 6ber load-elongation cura The time-aligned array model may be used to simulate a bundle when single fiber crimp, elongation, and toad are known. The bundle load at a given elongation is the sum of all individual 6ber loads at that elongation, assuming a constant tensile modulus. Cui was able to simulate the bundles and create realistic bundle loadelongation curves. Fiber bundle strength decreased as the standard deviation of single 5ber elongation increased, but bundle strength and elongation decreased with mean single fiber elongation [ 3 ] .Adams used a similar approach in his analysis of bundle load-elo...

Effects of non-lint material on heritability estimates of cotton fiber length parameters

“…Excessive trash content in the sample may create air channels through the plug of fibers, resulting in an unreliable micronaire reading. Furthermore, since the mass of trash in the sample is unknown, the true lint mass is unknown (Lord 1956;Fryer et al 1996).…”

Evidence and potential explanation of the influence of fiber length on the High Volume Instrument measurement of cotton fiber strength

“…Fryer et al 16,17 modeled the effect of varying the jaw placement (i.e. the distance D1 in Figure 1) on the HVI strength measurement and demonstrated that placing the jaws at different span lengths may introduce errors into strength measurements by changing the subset of fibers in the test.…”

Applications of Multicriteria Analysis in Cotton Mill

“…To produce a yarn with specific characteristics, the blend construction is very important; the knowledge of the fiber properties and the careful selection of fiber bales (adequate to the spinning system) are considered critical stages of spinning preparation. High quality testing results for fiber characteristics (of bales) provide information to spinners, allowing the more efficient use of cotton [1][2][3][4].We propose the using of the statistical analysis with multicriteria decision-making tool, applicable by means of an easily approachable software STAT-ADM, in order to choose the most adequate mixture formula for appropriate rotor spinning yarn characteristics [5,6]. …”

“…To produce a yarn with specific characteristics, the blend construction is very important; the knowledge of the fiber properties and the careful selection of fiber bales (adequate to the spinning system) are considered critical stages of spinning preparation. High quality testing results for fiber characteristics (of bales) provide information to spinners, allowing the more efficient use of cotton [1][2][3][4].…”