4. Physical properties :
Color : ranges from white to creamy white.
Fiber strength : moderately strong fiber
tenacity is 3.0 to 4.9 gm/den
Elastic modulus : very low
Length : 1200 to 1500 times to its breadth
Crimp : Twisted on its longitudinal axis
SG : 1.54
Effect of sun light : strength will be reduced
color will turn into yellowish
Effect of Heat : turns into yellow color on 120°C
Luster : Low luster
Effect of moisture : 6 to 8% moisture
moisture regain is 8.5%
5. Electrical properties :
Good conductor
Resistant value of cotton coated with pan and ppy are 350 and 512Ω
Chemical properties :
Acids : damaged
Alkalis : excellent resistance by alkalis but it swells in caustic alkalis like
NaOH
Effect of organic solvents : high resistance to normal cleaning solvents .
6. Morphology of rayon
Rayon chain are flexible because :
1. presence of oxygen in rayon fiber rings
2. ribbon like arrangement of chains due to hydrogen bonding
• It has fringed micelle structure
7. Physical Properties :
• Moisture content :
It has high moisture content.
• Tensile strength :
It has high tensile strength than cotton.
Its tensile strength is high in dry state than in wet state.
• Elongation at break : 15% to 30%
• Density : 1.50 g/cm^3
• Heat :
It loses strength above 300°F and its decomposition temperature is
350 to 400 °F.
It weakens in presence of UV.
8. Chemical Properties :
Acid :
It has much more vulnerable to acids than cotton
It can be used with dilute organic acid
Solvent :
It dissolves in ammonium hydroxide solution.
Microorganism :
It is rarely attacked by microorganism.
9. Physical Properties :
Tenacity : 6.0 to 8.5 gm/den
When fabric is immersed in water there is slight drop in tenacity but
this is fully reversible on drying.
Density : 1.14 gm/cc
Elongation at break :
Elongation at break ranges between 15 to 45%
Elasticity : Good elasticity
stronger than polyester fibers
Moisture regain : 3.5 to 5 %
10. Ability to protest friction : excellent
Ability to protect heat : Upto 150°C.
Quite resistant to heat.
On burning ,nylon tends to melt instead of burning.
Light Reflecting ability : Not good
Melting Point : Nylon 6 melts at 225°F
Nylon 6,6 melts at 250°F
Resiliency : good
The filament yarns provide a smooth , soft and lightweight fabric of
High resilience.
11. Chemical Properties :
Acids :
it has good resistance to acids at normal service contact but will disintegrate
on heating with concentrated acids.
both nylon soluble in 80% acetic acid at boiling .
both nylon soluble in formic acid at room temperature.
Alkalis : Resistant to alkali .
Effect of Bleaching :
strong oxidizing agent is harmful for the nylon fabric .
Organic solvents :
It becomes soluble in any dense acid or phenol.
Dyes : 1. Direct dyes. Water Resistance : it can not absorb water in
2. Acid dyes. high Amount .
3. vat dyes.
13. Physical Properties :
Tenacity : 5 to 7 gm/den
Elongation at break :15 to 30%
Elastic modulus : 90
Elasticity : Good
Moisture Resin : 0.40%
Specific Gravity : 1.38
Melting point : 250°C
14. Volumetric Swelling : None
Ability to protest Friction : excellent
Color : White
Light Reflection Ability : Good
Luster : Bright
Two main areas where problem occurs :
1. Adhesion problem
2. thermal shrinkage
15. Electrical properties :
Ester group will impart polarity.
Aromatic group will impart thermal and mechanical Resistance.
Polyester has low Electric conductance.
Chemical Properties :
Water : not significantly affected by immersion in water
Reduced Tenacity can be regain by drying
standerd regain is 0.5%
Heat : Quite Resistant
Melting Point : 250
Acids : Quite Resistant
Alkalis : good Resistant
16. Solvents :
resistant to 1. standard hydrocarbon
2. aromatic and chlorinated solvents
soluble In 1. phenols
2. cyclo-hexanone
3. benzyl alcohol
4. nitrobenzene
5. dimethyl phthalate etc.
17. Structure :
Chemical properties :
• it have high moisture absorption due to hydrophilic nature.
• They are resistant to strong acid and base at higher temperature .
• It is resistant to the attack of organic solvents and aqueous solution.
18. Thermal properties :
•It doesn’t melt but it decomposes at 500-575°C .
•burned with very difficulty
•Low shrinkage
•At 300°C Aramid retains 50% of its strength as it was at room temperature.
Mechanical properties :
•High tenacity
•Behaves elastically in tension.
•On compression they shows non-linear plastic deformation
Electrical properties :
•High dielectric strength even at high tempreature.
19. Nylon
Polyester
Nylon Fibers
Molds and Resins
Food Packaging
Filaments
Tire cords , Ropes , seat belts , hoses , tents etc.
Clothing
Bottles , Films , LCD , Film Insulation
Widely used for finishing of high quality wood
Polyester are now days replaced by nylon
20. Aramid :
In military and aerospace applications
Composite materials
Optical fiber cables
Flame resistant clothing
Jet engine enclosures
Heat protective clothing and helmets
Cotton : To produce yarn
Coffee filters , fishing nets , tents , etc.
Rayon : For making dresses , saris , etc
For finishing of bed sheets , blankets
Carpets
Medical field
