Production of manufactured fibers

Chapter 4 Production of Manufactured Fibers 70% of all textiles used Apparel – 48% Home furnishings – 40% excluding floor coverings Floor coverings – 99% Industry – 91% Characteristics of Manufactured Fibers y Quantities can be controlled easily b/c not dependent on nature y Properties may be tailored to the needs of the consumer y Blending of manufactured fibers ◦ With natural fibers - optimize end product characteristics Ex. polyester/cotton blend: cotton gives comfort and pleasant hand polyester adds resilience and durability Categories of Manufactured Fibers y Three main categories ◦ Manufactured Cellulosics x Derived from wood pulp and cotton linters x Cannot be used as textiles in their original form ◦ Synthetics x Created from petrochemicals ◦ Inorganic fibers x Glass x Metal x Ceramic Generations of Manufactured Fibers y First generation ◦ Regenerated from natural materials x Rayon y Second generation ◦ Synthesized from petroleum products x Nylon y Third generation ◦ Developed within the past 20 years ◦ High-performance or high technology x Microfibers Formation of Manufactured Fibers y Spinning ◦ Process of making a manufactured fiber x Polymer (fiber forming substance) gets melted into dope x Dope is extruded/forced through a Spinneret ◦ Spinneret x Looks like a showerhead x Has multiple holes, each one creates one filament Antron® nylon solution dyed polymer chips 6 Spinneret Filament Fiber Production Filaments extruded simultaneously y Each filament does not touch each other y Filaments are hardened as they emerge from the Spinneret y Several techniques for hardening the filaments y Described by the number and size of the filaments ◦ 70/40 x Yarn is 70 denier and there are 40 filaments Hardening Techniques for Filament Fibers y Melt spinning ◦ Polymer melted ◦ Force thru Cool air to solidify ◦ Simple / less expensive Nylon, olefin, polyester, saran and glass Hardening Techniques for Filament Fibers y Dry spinning ◦ Polymer dissolved in solvent ◦ Extruded into warm, dry air ◦ Warm air dissolves the solvent + hardens the filament ◦ Acetate, vinyon, some acrylics [...]... insoluable fibers – high melting points ◦ Teflon® ◦ GORE-TEX® fabrics Specialized Fiber Formation Heterogeneous fibers ◦ Bicomponent Hollow fibers Microfibers Fibrillated fibers Advantages of Bicomponent Fibers Single fiber has characteristics of both polymers ◦ Increased comfort ◦ Better absorbency ◦ Cross-dyed effects can be achieved Bilateral Fibers Also called side-by-side bicomponent fibers ◦ Two... Fig 4-4a p.58 ◦ Benefit of crimp Result of one fiber shrinking more than the other Crimped fibers have: Improved hand Increased cover Loft elasticity Sheath-Core Fibers Spun so one fiber encases the other ◦ See #43 on p.26 of your Swatch Kit ◦ Refer to Fig 4-4b on p 58 of textbook Matrix or Biconstitute Fibers Created with two generically different fibers ◦ Fine, short lengths of one fiber embedded in... Photomicrograph of hollow nylon fibers (cross section) 22 Microfibers Produced by carefully controlled melt spinning ◦ Splitting method Two incompatible polymers are extruded then separated ◦ Sea-island method Polymer for the microfiber is embedded into another polymer Also called microdenier fibers Characteristics ◦ Soft ◦ Excellent drape Fibrillated fibers ◦ Characteristics Coarse fibers used for... 8 p 61 for a detailed summary of the process Antron® nylon staple tow 32 Additional Treatments Applied during the spinning process ◦ Additives such as: Dyes Pigments Delusterants Whiteners Chapter 5 Manufactured Cellulosic Fibers Two categories Regenerated cellulosic fibers Derivative cellulosic fibers Both made from cotton linters and wood pulp Regenerated Cellulosic Fibers Rayon ◦ ◦ ◦ ◦ Pure cellulose... Characteristics Coarse fibers used for bagging and twine ◦ Extrude asheet of polymer ◦ Draw and stretch the sheet This causes it to break into interconnected fibers Manufactured Fiber Modifications Dictated by the Projected End Use Drawing Heat setting Texturing Cutting Modifications continued Drawing –parallel alignment or orientation of molecules Partially oriented yarns (POY) ◦ Not drawing to the maximum... extrusion Fig 4-5 Hollow Fibers Have one or more spaces in their centers Fig 46 p 58 ◦ Air injected into fiber as it is being formed ◦ Shape determined by spinneret holes ◦ By adding gas producing compounds to the spinning solution Lightweight and trap air ◦ Often used for cold weather clothing Thermolite® by DuPont ITS Intertek Testing Services Labtest Photomicrograph of hollow nylon fibers (cross section)... dimensional stability of thermoplastic yarns Create permanent pleats and creases Pleats Heat Set into Polyester Modifications continued Texturing – Produces the following: ◦ Bulkier yarns ◦ Opaque yarns ◦ Yarns with elastomeric qualities Since synthetic fibers are moldable, they will retain a permanently textured shape Modifications continued Cutting ◦ Creates staple yarns from filament fibers ◦ Extruded...Hardening Techniques for Filament Fibers Wet spinning ◦ Polymers dissolve in chemical bath ◦ Extruded into other chemical bath ◦ Acrylic and viscose rayon Hardening Techniques for Filament Fibers Solvent spinning ◦ ◦ ◦ ◦ Newest process Polymer is dissolved in amine oxide Extruded into solvent bath Tencel, Lyocell Special-Use Spinning Methods Gel Spinning ◦ ◦ ◦ ◦ Hybrid of wet + dry spinning Also called . Formation y Heterogeneous fibers ◦ Bicomponent y Hollow fibers y Microfibers y Fibrillated fibers Advantages of Bicomponent Fibers y Single fiber has characteristics of both polymers ◦ Increased. past 20 years ◦ High-performance or high technology x Microfibers Formation of Manufactured Fibers y Spinning ◦ Process of making a manufactured fiber x Polymer (fiber forming substance) gets. Chapter 4 Production of Manufactured Fibers 70% of all textiles used Apparel – 48% Home furnishings – 40% excluding floor coverings Floor coverings – 99% Industry – 91% Characteristics of Manufactured