Fundamentals of Textile & Man made fiber

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Fundamentals of Textile & Man made fiber

  1. 1. Southeast University Department Of Textile Engineering I/A 251,252 Tejgaon Dhaka Bangladesh Prepared by : Mazadul Hasan sheshir
  2. 2. Welcome to our presentation
  3. 3. • • • • • • • • • • • • Textile & Textile fiber Man-made fiber & it’s classification Definition of different types of man made fiber Flow chart of synthetic process of man made fiber. Properties of man made fiber. Influence of chemical structure on man made fiber. Spinning process & it’s general principle. Different types of spinning process with figure. Viscose & it’s manufacturing process Note on cuprammonium rayon . Lyocell & its process flowchart. Notes on cotton count ,Denier, tex , millitex & their conversion.
  4. 4. Textile, Textile Fiber & it’s classification Textile : A textile is a flexible material consisting of a network of natural or artificial fibers oftenreferred to as thread or yarn. Textile Fiber: Textile fibers are defined as unit of matters characterized by flexibility, fineness, and high ratio of length to thickness. Classification of Textile Fibers: • Naturally occurring fibers of vegetable origin. • Naturally occurring fibers of animal origin. • Regenerated man-made fibers which use some naturally occurring substance as the raw material. • Synthetic man-made fibers which use synthetic organic compounds as the raw material. • Mineral fibers which are entirely inorganic.
  5. 5. Denier The denier of a yarn is the wt. in gms of a length of 9000m of that yarn. • The coarseness of a yarn or a filament is usually gauged as denier. • Denier is a unit of measure for the linear mass density of fibers. • If 9000 meters of yarn weigh 100 grams - the yarn is said to be 100 denier. • The term micro-denier is used to describe filaments that weigh less than one gram per 9,000 meter length.
  6. 6. Denier • Filament Denier only relates to a single filament. • Total Denier relates to a yarn, an agglomeration of filaments. • D.P.F. = Total Denier Quantity of Uniform Filaments (D.P.F is commonly known as Denier per Filament) • If a yarn of 100 denier is composed of either 20 or 60 filaments, then the filament denier will be: • For 20 filaments yarn, D.P.F. =100/20 =5 denier -coarse filament • For 60 filaments yarn, D.P.F. =100/60 =1.7 denier -fine filament
  7. 7. Cotton Count, Tex & millitex The yarn numbering system based on length and weight originally used for cotton yarns and now employed for most staple yarns spun on the cotton or short-staple, system. • It is based on a unit length of 840 yards, and the count of the yarn is equal to the number of 840-yard skeins required to weigh 1 pound. • Under this system, the higher the number, the finer is the yarn. Tex is a unit of measure for the linear mass density of fibers and is defined as the mass in grams per 1000 meters. The most commonly used unit is actually the decitex abbreviated dtex, which is the mass in grams per 10,000 meters. When measuring objects that consist of multiple fibers the term "filament tex" is sometimes used, referring to the mass in grams per 10,000 meters of a single filament.
  8. 8. Conversion factor for 1s cotton counts • 840 yds. of cotton weighs =1 lb • 840 m " " weighs =453.6 X 1.093613298 gm • 9000 m " " weighs =453.6 X 1.093613298 X 9000/840 gm • = 5315 gm or 5315 (equivalent denier or conversion factor) Therefore, for 25s, Denier (D) = 5315 / 25, that is, D = 5315 / C • 50s cotton count • 2/50s cotton count • 106.3 denier = 5315/50 = 106.3 denier = 5315/25 = 212.6 denier = 5315/106.3 = 50s cotton count
  9. 9. From the linear mass density of fibers 9 denier ≈ 1.0000 tex 1 denier ≈ 0.1111 tex So any number of D (Denier) ≠ any number of T (Tex) From above or or or T = D X 0.1111 T = (5315 / C ) 0.1111 (as we know D = 5315 / C) T = 590.5 / C TC = 590.5 = 591
  10. 10. Man-made fiber & it’s classification Man-made Fiber : A class name for various fibers (including filaments) synthetically produced from fiber-forming substances which usually refer to all chemically produced fibers to distinguish them from truly natural fibers such as cotton, wool, silk, flax, etc Classification: Man made fiber can be classified into three classes: a. Those made from natural polymers. b. Those made from synthetic polymers. c. Those made from inorganic materials.
  11. 11. Classification flowchart of man made fiber Man Made Fibres Organic By transformation of natural polymer Viscose Cupro Acetate Triacetate Lyocell Modal Elastodiene Inorganic From synthetic polymer Polyester Polyamide Acrylic Modacrylic Polypropylene Polyethylene Elastane Aramid Carbon Ceramic Glass Metal
  12. 12. Flow chart of synthetic process of man-made fiber: Synthetic fiber has its beginning with chemistry A media is developed & is filtered under pressure It is then extruded into continuous filaments The filaments are allowed to solidify Then they are stretched A finishing solution is then applied Then the bundle of filaments is crimped Cutting the bundle into staple length.
  13. 13. Different types of man made fiber. Regenerated Fiber: The man-made fibres, derived from naturally occurring polymers are known as regenerated fibres. For instance rayon and acetate are made of the same cellulose polymers that make up cotton. In the case of rayon and acetate, the cellulose is acquired in an altered state usually from woodPulp operations. Synthetic Fiber: Another group of man-made fibres is the synthetic fibers. Synthetic fibres are made of polymers that do not occur naturally. They are produced entirely in the chemical plant or laboratory, almost always from by-products of petroleum. Fiber produced from these polymers include nylon, polyesters, acrylics, the polyurethanes, etc
  14. 14. Inorganic Fiber: The man made fiber ,derived from inorganic substance is called inorganic fiber.Glass , Carbon, Ceramic & Metal are the example of inorganic fiber. Basic Characteristics: A synthetic polymer must have to have suitable characteristics with respect to several physical and chemical properties. These are: a. A high softening point. b. Adequate tensile strength . c. Soluability or melting ability for spinning. d. A high modulus or stiffness.
  15. 15. In addition to the primary requirements, many other properties of the material are important Chemical Physical Biological Fabric Properties Stability towards -acids -bases -solvents -bleaches -heat -sunlight -ageing -flammability -dyeability Mechanical -tenacity -elongation -stiffness -abrasion resistance -tensile recovery Thermal -melting point -softening point -glass transition temperature -decomposition temperature Electrical -surface resistivity Toxicological Dermatological Resistance to -bacteria -molds Appearance -drape -hand -lustre Comfort -warmth -water sorption -moisture retention -wicking Stability -shape -shrinkage -felting -pilling -crease resistance -crease retention -insects
  16. 16. Influence of chemical structure on properties Olefins (alkenes), a family of hydrocarbon compounds—which are produced from the refining of petroleum and natural gas —contains one double bond between two carbon atoms. The general chemical formula can be represented as CH2=CHR, with R representing any of several possible atoms or groups of atoms. As the repeating unit of a polymer, CH2 CH the compound has the following chemical structure: n Polypropylene is a material of moderately high melting R temperature (176 °C) that can be melt-spun into fibres useful for several types of clothing, upholstery, carpets, and nonwoven fabrics. When R is hydrogen (H), the polymer is polyethylene, a relatively low-melting material (137 °C) that finds use as a fibre in industrial applications—e.g., nonwoven fabrics—but not in most household applications. Still another variation is found when R represents a cyano, or nitrile, group (-C≡N), containing carbon and nitrogen linked by a triple bond. In this case the polymer obtained is polyacrylonitrile, an acrylic that does not melt without decomposition and therefore must be solution-spun into fibres used in clothing, drapes, and carpets. It is observed from the structural variations that the methyl and cyano groups in polypropylene and polyacrylonitrile raise melting points.
  17. 17. Different Types of Spinning There are typically three types of spinning for polymers: Melt, Dry and Wet. ▪ Melt spinning is used for polymers that can be melted easily. ▪ Dry spinning involves dissolving the polymer into a solution that can be evaporated. ▪ Wet spinning is used when the solvent cannot be evaporated and must be removed by chemical means.
  18. 18. Melt spinning Melt spinning is the preferred method of manufacture for polymeric fibers. The polymer is melted and pumped through a spinneret (die) with numerous holes (one to thousands). The molten fibers are cooled, solidified, and collected on a take-up wheel. Stretching of the fibers in both the molten and solid states provides for orientation of the polymer chains along the fiber axis. Polymers such as poly(ethylene terephthalate) and nylon 6,6 are melt spun in high volume.
  19. 19. Dry Spinning Dry Spinning: In dry spinning the fibre-forming substance is dissolved in a solvent before the solution is extruded. As the jets of solution emerge from the spinneret, a stream of hot air causes the solvent to evaporate from the spinning solution, leaving solid filaments. Acetate is dry spun by extruding acetone solutions of cellulose acetate into hot air.
  20. 20. Wet Spinning Wet Spinning: In wet spinning the solution of fibre-forming material is extruded into a coagulating bath that causes the jets to harden as a result of chemical or physical change.Viscose, for example, is wet spun. The solution of cellulose xanthate is extruded into an aqueous solution of acids and salts, in which the cellulose is regenerated to form solid filaments
  21. 21. Comparative features of melt, dry and wet spinning Features Melt Dry Wet Investment Cost Low High Low Hazard Non-toxic (Risk of explosion) Toxic Heat of Spinning High High Low 300-900 20,000-75,000 2500-3000 ft/min 150-300 ft/min Spinneret Hole Spinning Speed 2 to many thousand 2500-3000 ft/min Toxic
  22. 22. Manufacture of viscose rayon Viscose rayon is a regenerated cellulose fibre. Because it is produced from naturally occurring polymers.The raw materials for viscose rayon may be cotton linters, the short fibres adhering to the cotton seed, or wood pulp derived from northern spruce, western hemlock, eucalyptus, or southern slash pine. The pulps of these soft woods, containing about 94 percent cellulose, are especially suited to fibre manufacture. Wood contains other substances like lignin, besides cellulose. So it is purified, treated with caustic soda, which converts it into alkali cellulose, then treated with carbon disulphide, which converts it into sodium cellulose xanthate and then dissolved in dilute solution of caustic soda. The solution is then “ripened” and then spun into an acid coagulating bath, which precipitates the cellulose in the form of a viscose filament.
  23. 23. Manufacture Process Flow Chart Preparation of the wood pulp Conditioning of Wood Pulp Steeping (formation of soda cellulose) Shredding (cutting) Ageing Churning (Xanthation or Sulphidising) Mixing (dissolving) Ripening Spinning Wind up/Cutting

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