Staple (textiles)

A staple fiber is a textile fiber 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, and 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 into 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 (staple length). ^{[1][2][3][4][5][6]}

Etymology

The word staple, used about a fiber of wool, is attested from the 15th century; the use was later broadened to include other fibers such as cotton. The origin of the word is not known for certain. It may be a back-formation either from the obsolete noun stapler meaning wool-stapler, a merchant trading in wool who would sort and class the wool according to quality, or else from the obsolete verb staple, to receive goods such as wool at a staple port.^[7]

History

For cotton and wool, staple length was originally tested by hand, the tester removing a clump of fiber and then arranging it on a dark cloth for measurement. In the 1970s, machines were invented to do this task, taking around 5 minutes for cotton and for wool around 20 minutes. Today, machines such as Optical scanning methods like digital fibro graph and HVI are used to measure fiber length; they can measure the staple length efficiently.^[8][9][10]

Staple length

Staple length, a property of staple fiber, is a term referring to the average length of a group of fibers of any composition. Staple length depends on the origin of the fibers. Natural fibers (such as cotton or wool) have a range of lengths in each sample, so the staple length is an average. For synthetic fibers which have been cut to a certain length, the staple length is the same for every fiber in the group.

Staple length is an important criterion for spinning fiber, as shorter fibers are more difficult to spin than longer ones, so staple length varies from short to longer length fibers, short fibers also resulting in more hairy yarns. ^{[11][12][9][13]} Long staple fibers or extra-long staple fibers produces soft linens, and superior clothing products. Fine (thin) yarn requires long fibers.

Cotton traders use many systems to classify the quality of cotton fiber. One of the most significant distinctions is "staple length", length of the individual fibers. Traditionally, cultivars of Gossypium barbadense fall into the "long-staple" category. The term extra-long staple (ELS) first came into use in 1907. The International Cotton Advisory Committee, in an attempt to standardize classification, defined extra-long-staple as 1⅜ inches (34.9mm) or longer, and long-staple as 1⅛ to 1 5/16 inches (28.6 to 33.3 mm). Under this classification scheme, most cultivars of G. barbadense produce extra-long-staple fibers, but some cultivars qualify as long-staple.^[3]

Categorization of staple length

Short staple cotton fibers produce carded yarns that are generally irregular and have protruding hairs, hence a cheap yarn quality. Long-staple fibers contribute to better spinnability and strength, delivering regular yarns of superior quality. The staple length of cotton fibers are divided into 19 lengths with a fixed range. The United States Department of Agriculture categorizes the staple length of cotton fibers for convenient cotton classing as follows:^[14][15][16]

Category	Fiber length (Inches)
Very Short staple	<0.25
Short staple	0.25-0.94
Medium staple	0.94-1.13
Long staple	1.13-1.38
Extra long staple	>1.38

Wool

In wool, fineness is the major criterion.^[17] Wool classification and grading are focused on measuring the wool's diameter in microns; Merino wool is typically 90–115 mm (3.5–4.5 in) in length and is very fine (between 12 and 24 microns).^[18] Longer (more than 3 in (7.6 cm)) and finer wool yarns are used in fine worsted materials, and coarser and short-staple yarns (1–3 in (2.5–7.6 cm)) produce woolen materials. Worsted fabrics are smoother and more expensive.^[19][20][21]

Filament fiber

Synthetic fibers are produced artificially by humans through chemical synthesis. The process includes polymerization. These fibers are formed with extruding fiber-forming materials through spinnerets. The product is continuous strands. These are called filament yarns. Examples of synthetic fibers are polyester, polyamide, and acrylic. Silk is the only natural fiber obtained as a filament.^[22][5][6]

If filament fiber is cut into discrete lengths, it becomes staple fiber.

Core-spun yarn

Like blended fabrics, the staple fibers have an important use in core-spun yarn; they are produced by wrapping various staple fibers around a filament yarn. For instance, in a cotton polyester core-spun yarn, cotton wraps around a polyester filament yarn. Similarly, core-spun cotton spandex is a yarn in which cotton fibers are twisted around a spandex yarn and covers the core yarn and are primarily used in denim types. Plying two or more core-spun yarns are used for making core-spun threads.^{[23][24][25][26]}

See also

• Staple (wool)
• Extra-long staple cotton

References

1. Wingate, Isabel Barnum (1979). Fairchild's dictionary of textiles. Internet Archive. New York : Fairchild Publications. pp. 583, 496. ISBN 978-0-87005-198-2.
2. "Staple Fiber - an overview | ScienceDirect Topics". www.sciencedirect.com. Retrieved 2021-04-29.
3. Porcher, Richard D. (2010). The story of Sea Island cotton. Sarah Fick. Salt Lake City, Utah. p. 56. ISBN 978-0-941711-73-9. OCLC 61878949.{{cite book}}: CS1 maint: location missing publisher (link)
4. American Home Economics Association. Textiles and Clothing Section (1970). Textile handbook. Internet Archive. Washington, American Home Economics Association. p. 7.
5. Burkinshaw, Stephen M. (2016-02-08). Physico-chemical Aspects of Textile Coloration. John Wiley & Sons. p. 2. ISBN 978-1-118-72569-6.
6. ''The filament is <1 mm in maximum cross section (i.e., diameter, in most cases). A filament can be compared ... Manufactured fibers are produced either as continuous infinite length filaments or cut staple of desired length value.'' Engineering Cotton Yarns with Artificial Neural Networking (ANN)books.google.co.in › books Tasnim N. Shaikh, Sweety A. Agrawal · 2017
7. "staple, n.3". OED Online. April 2021. Oxford University Press
8. Johnston, D. D. (Donald D. ); Ray, H. D. (H Dean); Pohle, E. M. (Elroy M. ) (1957). Staple length sampling schedules for raw wool packaged in bags. National Agricultural Library U. S. Department of Agriculture. [Washington, D.C.] : U.S. Dept. of Agriculture, Agricultural Marketing Service, Livestock Division.
9. Saville, B. P. (8 January 1999). Physical Testing of Textiles | ScienceDirect. Elsevier Science. ISBN 9781855733671. Retrieved 2021-04-29.
10. "Fibre Length - an overview | ScienceDirect Topics". www.sciencedirect.com. Retrieved 2021-04-29.
11. Rogers, Clarence D.; Bargeron, Jefferson D. (1979). Influence of Staple-length Variations on the Spinning Performance and Yarn Quality of Cotton. Department of Agriculture, Science and Education Administration. p. 2.
12. Pakistan Textile. All Pakistan Textile Mills Association. 1977. pp. 39–41.
13. Hollen, Norma R.; Hollen, Norma R. Textiles (1988). Textiles. Internet Archive. New York : Macmillan. p. 6. ISBN 978-0-02-367530-0.
14. Kadolph, Sara J. (2007). Textiles. Internet Archive. Upper Saddle River, N.J. : Pearson Prentice Hall. pp. 45, 46. ISBN 978-0-13-118769-6. Cotton classification describes the quality of cotton in terms of staple length, grade, and charac¬ ter. Fiber-length classifications for cotton include very-short-staple cotton (less than 0.25 inch), short- staple cotton (0.25 to 0.94 inch), medium-staple cotton (0.94 to 1.13 inches), ordinary long-staple cotton (1.13 to 1.38 inches), and extra-long- staple cotton (1.38 inches). Staple length is based on the length of a representative bundle of fibers from a bale of cotton. There are 19 staple lengths, ranging from less than inch
15. Kadolph, Sara J. (1998). Textiles. Internet Archive. Upper Saddle River, N.J. : Merrill. pp. 38, 39. ISBN 978-0-13-494592-7.
16. Hathorn, Scott (1951). American-egyptian co. pp. 34, 35, 36.
17. "Wool Grading" (PDF). 2012-03-14. (PDF) from the original on 2012-03-14. Retrieved 2021-05-29.
18. . 2006-11-05. Archived from the original on 2006-11-05. Retrieved 2021-05-29.
19. Gilligan, E. G. (2004-01-05). Woollen and Worsted Woven Fabric Design. Elsevier. p. 7. ISBN 978-1-84569-317-6.
20. McLaren, Walter Stowe B. (1884). Spinning woollen and worsted. p. 58.
21. "Manufacturing of Worsted and Woolen Yarns". Retrieved 2021-05-31.
22. MATHEWS, KOLANJIKOMBIL (2017). Encyclopaedic Dictionary of Textile Terms: Four Volume Set. Woodhead Publishing India PVT. Limited. p. 1342. ISBN 978-93-85059-66-7.
23. MATHEWS, KOLANJIKOMBIL (2017). Encyclopaedic Dictionary of Textile Terms: Four Volume Set. Woodhead Publishing India PVT. Limited. p. 361. ISBN 978-93-85059-66-7.
24. "Core-Spun Yarn - an overview | ScienceDirect Topics". www.sciencedirect.com. Retrieved 2021-05-04.
25. Textile Asia. Business Press. 2003. p. 59.
26. Muthu, Subramanian Senthilkannan (2017-06-12). Sustainability in Denim. Woodhead Publishing. p. 33. ISBN 978-0-08-102044-9.

External links

• ASTM Standard