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Nylons (Polyamides) PA semi-crystalline
INTRODUCTION
The name "nylons" refers to the group of plastics known as polyamides. Nylons are typified by amide groups (CONH) and encompass a range of material types (e.g. Nylon 6,6; Nylon 6,12; Nylon 4,6; Nylon 6; Nylon 12 etc.), providing an extremely broad range of available properties. Nylon is used in the production of film and fibre, but is also available as a moulding compound.
PROPERTIES
The majority of nylons tend to be semi-crystalline and are generally very tough materials with good thermal and chemical resistance. The different types give a wide range of properties with specific gravity, melting point and moisture content tending to reduce as the nylon number increases.
Nylons tend to absorb moisture from their surroundings. This absorption continues until equilibrium is reached and can have a negative effect on dimensional stability. In general, the impact resistance and flexibility of nylon tends to increase with moisture content, while the strength and stiffness below the glass transition temperature (< 50-80 oC) decrease.
Grades Available
There are many types of nylon available (e.g. Nylon 6 nylon 66, nylon 6/6-6, nylon 6/9, nylon 6/10, nylon 6/12, nylon 11, nylon 12). The material is available as a homopolymer, co-polymer or reinforced. Nylons may also be blended with other engineering plastics to improve certain aspects of performance.
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Psysical properties: |
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Tensile Strength |
56 - 90 |
MPa |
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E-modulus |
1000 - 2600 |
MPa |
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Notched Impact Strength |
5.0 - no break |
kJ/m² |
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Thermal Coefficient of expansion |
90 |
x 10-6 |
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Max Cont Use Temp |
168 - 250 |
0C |
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VicatB Temp |
80 - 150 |
0C |
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Density |
1.02 - 1.13 |
g/cm³ |
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Resistance to chemicals: |
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Dilute Acid |
Poor |
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Dilute Alkalis |
Good |
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Oils and Greases |
Very good |
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Aliphatic Hydrocarbons |
Very good |
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Aromatic Hydrocarbons |
Very good |
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Halogenerated Hydrocarbons |
Good |
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Density |
Poor | 
APPLICATIONS
Nylon fibres are used in textiles, fishing line and carpets. Nylon films is used for food packaging, offering toughness and low gas permeability, and coupled with its temperature resistance, for boil-in-the-bag food packaging.
Mouldings and profiles find many applications as replacements for metal parts, for instance in car engine components. Intake manifolds in nylon are tough, corrosion resistant, lighter and cheaper than aluminium. Its self-lubricating properties make it useful for gears and bearings.
Electrical insulation, corrosion resistance and toughness make nylon a good choice for high load parts in electrical applications as insulators, switch housings and cable ties. Another major application is for power tool housings. |
