FASH 15 textiles natural cellulosic fibers—seed fibers

1. FASH 15 textiles natural cellulosic fibers—seed fibers

2. natural cellulosic fibers • all plants contain fibrous bundles that give • strength to the stem & root • pliability to the leaves • cushioning or protection to developing seeds • natural cellulosic fibers • classified according to plant component from which they are removed: • seed • stem (bast) • leaf • miscellaneous—root, bark, husk, moss

3. natural cellulosic fibers hundreds have been used—we’ll focus on the ones that are more globally significant or have potential for future growth

4. natural cellulosic fibers properties common to all cellulosic fibers

6. seed fibers seed fibers develop in the seedpod of the plant to use the fiber it must be separated from the seed—seed is then used to produce oil & animal feed most important seed fiber? http://www.youtube.com/watch?v=_KZWe0sYglc

7. cotton • cotton is an important cash crop in more than 80 countries • the major producers in the world are: • China—32.0% • India—21.8% • USA—12.2% • Pakistan—7.8% • Brazil—5.7% • in 2007 worldwide, 113 million bales (480 lbs/bale)

8. cotton

9. physical structure of cotton—length • cotton fiber is a single cell—grows from the seed as a hollow tube over 1000 times as long as it is thick • staple length is very important: • affects how fiber is handled during spinning • relates to fiber fineness & tensile strength • longer cotton fibers are finer and make stronger yarns • range from ½ - 2 inches long • upland cottons: 7/8 – 1 ¼ inches, Mexico/Central America (97% of US crop) • long-staple cottons: 1 6/16 – 1 ½ inches, Egyptian/South American • short-staple cottons: less than ¾ inch, Indian/Eastern Asian

10. physical structure of cotton—length • long staple fibers are considered to be higher quality—produce softer, smoother, stronger & more lustrous fabrics: • Pima • Supima • Egyptian • Sea Island

11. physical structure of cotton—distinctive parts • the cotton fiber is made up of: • cuticle—waxlike film covering primary wall • primary wall • secondary wall—cellulose layers • lumen—central canal that carries nourishment

12. physical structure of cotton—convolutions convolutions are ribbon-like twists that characterize cotton twists form a natural texture that enables the fibers to cling to one another—thus despite short length spinning is easy convolutions may trap soil making cleaning more difficult

13. physical structure of cotton—fineness • cotton fibers vary from 16-20 micrometers in diameter • cross-sectional shape varies with maturity: • immature tend to be u-shaped • mature nearly circular

14. physical structure of cotton—color cotton is available in a range of colors—creamy white most desirable for dyeing purposes interest in naturally colored cottons is increasing due to less environmental impact—brown, rust, red, beige & green are available plant breeders continue to work to add blue, lavender & yellow

15. classification of cotton • describes the quality of cotton in terms of: • staple length—based on the length of a representative bundle; 19 staple lengths • grade—refers to color and absence of dirt, leaf matter, seed particles, motes/dead fibers, tangles (neps); 39 grades • character—includes aspects such as maturity, smoothness & fiber uniformity, fineness, strength and convolutions

16. chemical composition of cotton cotton is when picked is 94% cellulose—finished cotton is 99% cellulose cotton can be altered using chemical treatments or finishes EXAMPLE: mercerization—treating yarns or fabrics with sodium hydroxide causes a permanent physical change: makes fibers more absorbent and improves dyeability

17. properties of cotton—aesthetics cotton certainly has consumer acceptance matte appearance & low luster are standard drape, luster, texture & hand are affected by choice of yarn size & type, fabric structure, and finish cottons range from soft, sheer batiste to crisp, sheer voile to fine chintz & sturdy denim and corduroy

18. properties of cotton—durability cotton is a medium-strength fiber—30% stronger wet can be handled roughly during laundering & in use abrasion resistance is good—heavy fabrics more so than thinner fabrics fiber elongation is low, with low elasticity

19. properties of cotton—comfort cotton makes very comfortable fabrics for skin contact because of absorbency, soft hand & good heat and electrical conductivity static buildup is not a problem has no surface characteristics that irritate the skin good for use in hot, humid climates—moisture passes freely through fabric , thus aiding evaporation & cooling

20. properties of cotton—appearance retention overall appearance retention for cotton is moderate with very low resiliency hydrogen bonds holding molecular chains together are weak so it wrinkles easily all-cotton fabrics shrink unless finished otherwise; untreated cottons shrink less in cool water with drip dry cotton stays stretched out in areas of stress—such as elbows or knees

21. properties of cotton—care cotton can be washed with strong detergents and requires no special care during washing and drying white cottons can be washed in hot water—dyed cottons retain their color better if washed in warm water cotton releases most soils readily but soil-resistant finishes are desirable for some interior & apparel uses excessive bleaching weakens cellulosic fibers cotton fabrics respond best to steam pressing or ironing while damp—can be ironed safely at high temperatures

22. properties of cotton—care cotton draperies should be dry-cleaned cotton upholstery may be steam-cleaned with caution cottons should be stored clean and dry cotton is harmed by acids—fruit & fruit juice stains should be treated promptly cotton oxidizes in sunlight which causes yellowing and degradation—some dyes are especially sensitive

23. environmental concerns & sustainability • agrichemicals—pest control, defoliants • soil erosion • water-intensive • genetically-modified cotton ??? • long-term environmental & health effects are unknown • organic cotton—no synthetic commercial pesticides or fertilizers are used • transition cotton—produced on land where organic farming is practiced but 3 year minimum has not been met • green cotton— fabric that has not been bleached or treated with other chemicals • conventional cotton—everything else

24. environmental concerns & sustainability http://www.youtube.com/watch?v=O2Crnk9ZiZs

25. identification of cotton microscopic identification of cotton is relatively easy—convolutions are easily seen along the fiber burn tests verify cellulose fiber length helps identify content cotton is soluble is sulfuric acid

26. uses of cotton • cotton is the single most important apparel fiber in the US • also very important in interiors because of its versatility, natural comfort and ease of finishing and dyeing • sheets & pillowcases • blankets & bedspreads • draperies & curtains • upholstery • slipcovers • rugs • wall coverings

27. uses of cotton medical, surgical & sanitary supplies frequently made of cotton—can be autoclaved for sanitization technical uses include book bindings, luggage, handbags, shoes, slippers, tobacco cloth, woven wiping cloths recycled denim? paper currency, insulation

28. other seed fibers—coir coir comes from fibrous mass between outer shell and husk of the coconut has good resistance to abrasion, water & weather used for indoor/outdoor mats, rugs, floor tiles, and brushes floor textiles are extremely durable and blend with many interior styles http://www.youtube.com/watch?v=MM3uviXP0VU

29. other seed fibers—kapok kapok is obtained from the seed of the Java kapok (silk cotton) tree or the Indian kapok tree fiber is lightweight, soft, hollow, very buoyant; breaks down quickly difficult to spin into yarns—used mainly as fiberfill researchers are studying ways to blend kapok with cotton for apparel uses

30. other seed fibers—milkweed milkweed produces a soft, lustrous, hollow-floss seed fiber resembling kapok has been used as fiberfill in comforters, personal flotation devices and upholstery very difficult to spin into yarns because it is so weak, smooth and straight also known as silkweed fiber and asclepias cotton