The material. Back in 1945, the war in Europe just ended, the two most prized luxuries were cigarettes and stockings made of nylon. Nylon (PA) can be drawn to fibers as fine as silk and was widely used as a substitute for it. Today, newer fibers have eroded its dominance in garment design, but nylon-fiber ropes and nylon as reinforcement for rubber (in car tires) and other polymers (PTFE, for roofs) remain important. Nylon is used in product design for tough casings, frames and handles, and, reinforced with glass, as bearings gears and other load-bearing parts. There are many grades (Nylon 6, Nylon 66, Nylon 11, etc.), each with slightly different properties.
Composition
(NH(CH2)5C0)n
|
General properties |
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|
Density |
1120 – |
1140 |
kg/m3 |
|
Price |
*3.55 – |
3.91 |
USD/kg |
|
Mechanical properties |
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|
Young’s modulus |
2.62 – |
3.2 |
GPa |
|
Yield strength (elastic limit) |
50 – |
94.8 |
MPa |
|
Tensile strength |
90 – |
165 |
MPa |
|
Elongation |
30 – |
100 |
% |
|
Hardness—Vickers |
25.8 – |
28.4 |
HV |
|
Fatigue strength at 107 cycles |
*36 – |
66 |
MPa |
|
Fracture toughness |
*2.2 – |
5.6 |
MPa. m1/2 |
|
Thermal properties |
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|
Melting point |
210 – |
220 |
°C |
|
Maximum service temperature |
110 – |
140 |
°C |
|
Thermal conductor or insulator? Thermal conductivity |
Good insulator 0.23 – |
0.25 |
W/m. K |
|
Specific heat capacity |
*1600 – |
1660 |
J/kg. K |
|
Thermal expansion coefficient |
144 – |
149 |
p, strain/°C |
|
Electrical properties Electrical conductor or insulator? Electrical resistivity |
Good insulator *1.5 X 1019 – |
1.4 X 1020 |
puhm. cm |
|
Dielectric constant |
3.7 – |
3.9 |
|
|
Dissipation factor |
0.014 – |
0.03 |
|
|
Dielectric strength |
15.1 – |
16.4 X 106 |
V/m |
|
Polyamides are tough, wear and corrosion resistant, and can be colored.
|
Typical uses. Light duty gears, bushings, sprockets and bearings; electrical equipment housings, lenses, containers, tanks, tubing, furniture casters, plumbing connections, bicycle wheel covers, ketchup bottles, chairs, toothbrush bristles, handles, bearings, food packaging. Nylons are used as hot-melt adhesives for book bindings; as fibers—ropes, fishing line, carpeting, car upholstery and stockings; as aramid fibers—cables, ropes, protective clothing, air filtration bags and electrical insulation.
