Polyester_Fiber_Nylon_By_Ankit_Jaiswal
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Transcript of Polyester_Fiber_Nylon_By_Ankit_Jaiswal
Fibre
Fibres are the basic unit of all textile materials and products.
They are slender thread-like structures that can be spun into yarns and thread, and woven, knitted or felted into materials.
Composed of atoms of various elements, such as carbon, hydrogen, oxygen, sometimes of nitrogen and other elements (sulphur) in lower quantities
Come from plants, animals and minerals. Have short fibres, called staple fibres. The exception to this rule is silk, a
natural fibre whose continuous filaments are up to one kilometre in length.
Sources of natural fibres• Cotton from the cotton plant• Linen from the flax plant• Wool from sheep• Silk from silkworms
Synthetic fibres and regenerated fibres are man-made, usually from chemical and natural polymer sources.
Continuous filament fibres: Fibres are long and do not always have to be spun into yarn.
Sources of synthetic fibres• Viscose comes from pine trees or
petrochemicals. • Acrylic, nylon and polyester
come from oil and coal.
Viscose
Man-made Fibres
Slick and abrasion resistant Strong and resilient Resistant to most common
fibre degradants: sunlight (except for nylon)
Flame resistance varies widely
Low density Non-biodegradable
Common Properties
Man-made – Synthetic Fibres
• Fibers made by chemical synthesis are often called synthetic fibers.
• Examples: Polyester Acrylic Lycra Nylon
Polyester
Nylon
Man-made – Regenerated FibresFibres
regenerated from natural polymer sources.
Examples: Rayon Acetate
Acetate
Rayon
Polymerization
• Process of macromolecules formation through repetition of basic units (synthesis fibres).
• Activated and controlled during the process by various parameters: Temperature, pressure, catalysers and reaction stabilizers
• Two mechanisms of chemical reaction available for the synthesis of linear polymers:Poly-condensation - two molecules of same
type or of different types are joined together to form macromolecules by removing simple secondary products as water, hydrochloric acid, alcohol.
Poly-addition - joins together several molecules and redistributes the valence links existing in the monomers, however without removing secondary products.
Spinning
• The term spinning defines the extrusion process through spinnerets of fluid polymer masses which are able to solidify in a continuous flow.
• The polymer processing from the solid to the fluid state can take place with two methods:
Melting: applied on thermoplastic polymers which show stable performances at the processing temperatures (used by 70% of the fibres)
Solution: the polymer is solved in variable concentrations according to the kind of polymer and of solvent, anyhow such as to produce a sufficiently viscous liquid. (used by 30% of the fibres)
Drawing
• The polymer extruded by the spinnerets in form of filaments has not yet the properties which are typical of a textile fibre: poor thermal and chemical stability, low resistance to ageing, high plasticity
• To develop strength, pliability, toughness, and elasticity properties.
Issue 1:Silk Production CausesPainful Death for Insects
• Silkworm is a domesticated insect. • Undergoes stages of metamorphosis:
egg, larva, pupa, and adult. • Silk derived from the cocoons of
larvae. Most of the insects raised by the industry don’t live past the pupa stage
• They are steamed or gassed alive in their cocoons. Approximately 3,000 silkworms are killed to make every pound of silk.
General Properties of Nylon
• Functional group is amide • Light in weight• Incredible tensile strength• Durability• Resistance to damage• Takes dye easily• Absorbs most water• Greater stretchability • Dries slower • smoother and softer fabric
than polyester• Somewhat UV resistant
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Type of Nylon and its Manufacture
• In nylon, the repeating units contain chains of carbon atoms.
• There are various different types of nylon depending on the nature of those chains for example:– Nylon-6,6– Nylon-6
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Nylon-6,6
• Synthesised by polycondensationpolycondensation of hexamethylenediaminehexamethylenediamine and adipic acidadipic acid.
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• Hexamethylene diamine Hexamethylene diamine and adipic acid adipic acid are combined with water in a reactorcombined with water in a reactor. This produces produces nylon salt. nylon salt.
• The nylon salt is then sent to an evaporatorevaporator where excess water is removedexcess water is removed.
• The nylon salt goes into a reaction vessel reaction vessel where a continuous polymerization process takes placepolymerization process takes place. This chemical process makes molten nylon 6-6. molten nylon 6-6.
• The molten nylon -6,6 undergoes a spinning process, spinning process, where the nylon 6-6 is extruded and sent through a spinneret, which is a small metal plate with fine holes.
• The nylon is then air-cooled to form filaments.
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Uses of Nylons
• Synthetic replacement for silk• It replaced silk in military
applications such as parachutes and flak vests, and was used in many types of vehicle tires.
• Used in many applications, including fabrics, bridal veils, carpets, musical strings, and rope.
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• Artificial muscles have been crafted out of materials including metal wires and carbon nanotubes, but they have proven to be costly to make and tricky to control.
• According to research published in the journal Science on 20th February 2014, these scientists instead turned to high-strength polymer fibres made of polyethylene and nylon, materials found in everyday items like fishing line and sewing thread. They twisted the fibres into very tight coils and used changes in temperature to make the artificial muscles contract and relax.
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POLYESTER
The name "polyester“ (aka Terylene) refers to the linkage of several monomers (esters) within the fibre.
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o Colorless and transparento Smooth and lustrous o Shape as we requireo Shiny glass rod like
o Colorless and transparento Smooth and lustrous o Shape as we requireo Shiny glass rod like
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Characteristics of polyester
Characteristics of polyester
Strong Very durable Resistant to stretching and shrinking Quick drying Wrinkle resistant Mildew resistant Retains its shape good for making outdoor clothingEasily washed
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Drawing
•When polyester emerges from the spinneret, it is soft and easily elongated up to 5 times its original length.
•This helps to reduce the fibre width. •This fibre is now ready and would into cones as
filaments. It can also be crimped and cut into staple lengths as per requirement
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Some Major Polyester Fibre
Uses
Some Major Polyester Fibre
UsesApparel: Every form of clothing Home Furnishings: Carpets, curtains, draperies, sheets and pillow cases, wall coveringsOther Uses: hoses, power belting, ropes and nets, thread, tire cord, auto upholstery, sails, floppy disk liners, and fiberfill for various products including pillows and furniture
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Nylon Polyester
Functional group is amide
Functional group is ester
Absorbs most water Absorbs some water
Greater stretchability Resistant to stretching
Dries slower Dries quickly
smoother and softer fabric than polyester
polyester has always been a rougher fabric than nylon
Somewhat UV resistant More UV resistant
lightweight and durable synthetic fabrics
Mildew resistant
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Q3 : State 3 common manufacturing process of fibre
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Ans: •Polymerization (polycondensation or poly- addition) •Spinning•Drawing