4. • Acetate Rayon is a manufactured regenerated cellulose fiber.
• Purified cellulose , primarily from wood pulp.
• Converted into a soluble compound.
• Dissolved and forced through a spinneret.
• To produce filaments.
• Chemically solidified, resulting in synthetic fiber, pure
cellulose.
• Rayon is manufactured from naturally occurring polymer.
• It is considered a semi-synthetic fiber.
5. • Acetate rayon a synthetic filament, yarn, or fabric
composed of a derivative of the acetic ester of cellulose.
• Differing from viscose rayon in having greater strength
when wet and greater sensitivity to high temperatures.
High quality Acetate
fabric
6. • Origin :
• Acetate, which is properly called as cellulose acetate, was
first made by Paul Schützen berger, in 1869.
7. • The basic raw material for rayon is cellulose.
• Natural cellulose are – wood pulp, spruce, hemlock tree
and cotton linters.
• Cotton linters are residue fibers .
• Acetate Rayon is a manufactured fiber composed of
regenerated cellulose.
• It is a manufactured fiber in which substitutes have not
replaced more than 15 percent of the hydrogens.
8.
9.
10.
11. • The manufacturing acetate include cellulose, acetate
anhydride, plus sulphuric acid as a catalyst.
• Primarily from wood pulp, purified, bleached and shredded.
• The shredded is fed into pre-treatment tanks, mixed with
glacial acetic acid and held for a specified length of time.
• To kneading machines called acetylates and acetic
anhydride is added.
• Dissolved and becomes cellulose acetate. Clear liquid called
acid dope.
• The dope is aged, in special storage tanks ; water is added
as needed reduce the acid concentration.
• Hydrolysis occurs during the ripening; formation of
acetate.
• Secondary acetate solution in mixed with water.
• Precipitate out in the form of small flakes.
• The flakes are washed and dried
12. • Dissolved in acetone to form a spinning dope.
• This spinning solution is forced through filters to remove any
undissolved acetate and impurities and then through the
spinnerette into a warm air chamber.
• The acetone evaporates and the acetate coagulates as it falls
through the chamber.
• The filaments travelling downward are twisted together to form
yarn.
• Fiber manufacture is called dry spinning.
15. • Manufactures can produce a wide variety of fiber shapes
and confirmations.
• Acetate Rayon has low strength and requires careful
handling.
• But the desirable properties of hand, drape, and
appearance make the fabrics manufactured from these
fibres results in fabrics that become easily wrinkled and
permanently deformed.
• Moisture regain is slightly less than cottonattractive to
designers and consumers.
• The low elastic recovery of acetate, with its low resiliency,.
16. • Dilute alkalis have little effect on acetate.
• Concentrated acids weaken the fibres drastically and in
most instances cause complete disintegration.
• Dilute hot acids may cause, a loss of strength.
• Cold dilute acids weaken the fibre if exposure is prolonged.
• Petroleum solvents used in dry cleaning do not damage
acetate, phenol and chloroform will destroy the fibres.
• Storage may result in weaker acetate fibres.
• All acetate develops static charges, especially when dry,
because they are poor conductors of electricity.
17. • Fungi such as mildew and bacteria may discolour acetate
fibres.
• Moths and other households pests do not damage acetate.
• However, silverfish may attack heavily sized fibers in order
to eat the starch sizing.
18. • Acetate rayon is a thermoplastic fibre.
• Melt and burn, forming a hard, black bead ash.
• Odour is similar to that of hot vinegar.
19.
20. • A manufactured fiber in which the fibre-forming substance
is a long-chain synthetic polyamide, in which at least 85%
of the amide linkages are attached directly to two aromatic
rings.
21.
22. • Kevlar is a heat-resistant and strong synthetic fiber, related
to other aramids such as Nomex and Tecnora.
• Developed by Stephaine Kwolek at Dupont in 1965.
• First commercially in the early 1970s as a replacement for
steel in racing tires.
• Typically it is spun into ropes as an ingredient in composite
material components.
23. • Properties
• It is resistant to alkalis at room temperature.
• Kevlar is spun the resulting fiber has a tensile strength
about 3,620 Mpa and a relative density of 1.44.
• The polymer owns its high strength to the many inter chain
bounds .
• Hydrogen bounds form between the carbonyl group and NH
centres.
• Additions strength is derived from aromatic stacking
interaction between adjacent strands.
24. • Uses
• Bullet/stab proof vest or jackets.
• Diving gloves, walking boots, military helmet, cut resistant
gloves.
• Bicycle tyres cars tyres and fire proof clothing.
25.
26. • Nomex is a brand of lightweight, heat resistant aramid fiber
used in clothing especially for fire fighter and protective
fabrics.
27. • Properties
• Inherent dielectric strength
• Mechanical toughness
• Thermal stability
• Chemical compatibility
• Radiation resistance
• Flame resistance
• Moisture insensitivity
• Cryogenic capabilities.
• Inherent Dielectric Strength
• Nomex® products withstand short-term electrical stresses
of 18 kV/mm to 34 kV/mm (460 V/mil to 870 V/mil),
depending on product type and thickness.
• Mechanical Toughness
• Nomex® products are strong, resilient and (in the thinner
grades) flexible, with good resistance to tearing and
abrasion.
28. • Thermal Stability
• Temperatures up to 200°C have little or no effect on the
electrical and mechanical properties of Nomex® products.
• At temperature 370c (700f) Nomex degrades.
• Nomex® products are essentially unaffected by most
solvents and are unusually resistant to attacks by acids and
alkalis at room temperature.
• They are not attacked by insects, fungi or mold.
• Prolonged exposure to sodium hydroxide in concentration
greater than 50% at elevated temperature degrades nomex.
29. • Radiation Resistance
• Nomex® is essentially unaffected by 800 me garads (8
Mgy) of ionizing radiation and still retains useful
mechanical and electrical properties after eight times this
exposure.
• Flame Resistance
• Nomex® products do not produce known toxic reactions in
humans
• Nomex® products do not melt and, with a limiting oxygen
index (LOI) at 220°C above 20.8—the critical value for
combustion in air—they do not support combustion.
• Cryogenic Capabilities
• Nomex® products have found acceptance in a variety of
cryogenic applications due to their unique polymer
structure.
32. • Title : Essential of Textiles. Publisher: Holt, Rinehart and
Winston, INC. Year : Oct 1987.
Web Refernces:
• https://en.wikipedia.org/wiki/Rayon
• https://www.dupont.com/products/nomex-fibers.html
• https://www.dupont.com/what-is-kevlar.html
