Cotton classing

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Cotton classing is the measurement and classification of cotton by its specific physical attributes. This information is attached to individual bales, thus clarifying their value and helping producers market them. For cotton buyers, i.e. the spinning mills, this precise information about the cotton fiber enables them to achieve consistent yarn quality by optimizing raw material selection and blending.

Contents

History

According to the USDA, an international group of cotton industry representatives met 1907 in Atlanta, Georgia to address serious problems that had developed in the marketing of cotton. A resolution was passed which recommended the establishment of uniform cotton standards to “eliminate price differences between markets, provide a means of settling disputes, make the farmer more cognizant of the value of their product, and, therefore, put them in a better bargaining position, and in general be of great benefit to the cotton trade.” In response to this and similar calls for action over the next several years, laws were passed authorizing the USDA to develop cotton grade standards and offer cotton classification services. [1]

Since 1991, USDA cotton classification has applied an instrument-based classing process using the so-called High Volume Instrument (HVI) by Uster Technologies. [2]

Classification of cotton

Classification of cotton, or cotton classing, is based on fiber characteristics that include staple length, strength, cotton maturity, micronaire (a measure of the cotton's fineness), color grade, color reflectance, color yellowness, and trash percent area. [2] [3]

In order to improve objectivity, cotton classing has largely moved from human senses (visual checks by certified classers) to high-volume, precision instruments that measure different parameters in a matter of seconds. [4] [3]

Cotton classing is usually organized by governmental agencies for the entire crop grown in their own countries. The first body to systematically conduct instrument-based classing was the United States Department of Agriculture (USDA), running a series of air-conditioned classification offices where the entire cotton crop is sampled and classified. Other countries running similar classification organizations include China, Australia, Uzbekistan, Brazil and Greece. [4]

Staple length

Staple length is a term referring to the average length of a group of fibers of any composition. Short staple cotton fibers produce carded yarns that are generally irregular and have protruding hairs, hence a low yarn quality. Long-staple fibers contribute to better spinnability and strength, delivering regular yarns of superior quality. The USDA standardizes staple length as follows: [5] [6]

CategoryFiber length (Inches)
Very Short staple<0.25
Short staple0.25-0.94
Medium staple0.94-1.13
Long staple1.13-1.38
Extra long staple>1.38

Cotton grading

There are 39 cotton color grades.

Color is described as white, light spotted, spotted, tinged, or yellow. Color is also described in terms of lightness to darkness: plus, light gray, and gray.

Textiles by Kadolph, Sara J

[3]

Cotton maturity

The maturity of individual cotton fiber is an essential aspect of cotton classing. Cotton maturity also contributes to the aesthetics of the product. For instance, it may affect appearance. Therefore, immature cotton that does not absorb dye is called ''dead fiber'', ''dead cotton'', and ''mote fibers.'' [7] [8] [3]

See also

Related Research Articles

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A textile is a flexible material made by creating an interlocking bundle of yarns or threads, which are produced by spinning raw fibers into long and twisted lengths. Textiles are then formed by weaving, knitting, crocheting, knotting, tatting, felting, bonding, or braiding these yarns together.

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Staple refers to textile fibers of discrete length. The opposite is a filament fiber, which comes in continuous lengths. Staple length is a characteristic fiber length of a sample of staple fibers. It is an essential criterion in yarn spinning aids in cohesion and twisting. Compared to synthetic fibers, natural fibers tend to have different and shorter lengths. The quality of natural fibers like cotton is categorized on staple length such as short, medium, long-staple and, extra long. Gossypium barbadense, one of several cotton species, produces extra-long staple fibers. The staple fibers may be obtained from natural and synthetic sources. In the case of synthetics and blends, the filament yarns are cut to a predetermined length.

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Uster Technologies Swiss manufacturer of analytical instruments and on-line monitoring systems

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Cotton recycling

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A blend is an intimate mixture of two or more fibers. In yarn spinning, different compositions, lengths, diameters, or colors may be combined to create a blend. The term, blend, refers to spun fibers or a fabric composed of such fibers. There are several synonymous terms: a combination yarn is made up of two strands of different fibers twisted together to form a ply; a mixture or mixed cloth refers to blended cloths in which different types of yarns are used in warp and weft sides.

Aesthetics (textile) Concept of serviceability of textiles. It is determined by visual perception and the touch

Aesthetics in textiles is one of the basic concepts of serviceability of textiles. It is determined by the perception of touch and sight. Aesthetics imply the appearance and attraction of textile products; it includes the color and texture of the material. It is a statement about the end user (consumer) and the target market. When combined with fabric construction, the finish of the clothing material, garment fit, style, and fashion compatibility, colours create an aesthetic comfort. All of these elements work together to satisfy our visual perception. Aesthetics incorporates the role of evaluation also.

References

  1. ↑ "History and Scope". USDA.
  2. 1 2 "US cotton standards". United Nations Conference on Trade and Development. Archived from the original on 2007-02-14. Retrieved 2009-12-10.
  3. 1 2 3 4 Kadolph, Sara J. (2007). Textiles. Internet Archive. Upper Saddle River, N.J. : Pearson Prentice Hall. pp. 45, 46. ISBN   978-0-13-118769-6.
  4. 1 2 "The Classification of Cotton". Cotton Inc. Retrieved 2022-02-09.
  5. ↑ Kadolph, Sara J. (1998). Textiles. Internet Archive. Upper Saddle River, N.J. : Merrill. pp. 38, 39. ISBN   978-0-13-494592-7.
  6. ↑ American-egyptian co. 1951. pp. 34, 35, 36.
  7. ↑ Service, United States Agricultural Research (1944). Research Achievement Sheet. p. 127.
  8. ↑ "The Classification of Cotton". 2011-01-14. Archived from the original on 2011-01-14. Retrieved 2021-01-14.
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