Blog | Polyalto

What is Nylon? Nylon 6 and 66

Rédigé par Groupe PolyAlto | Jan 31, 2023 10:16:12 PM

Plastic nylons are popular synthetic materials known for many industrial and domestic uses. Typically, they are used in the synthetic textile industry, along with polyester and spandex. However, these plastics are also recognized in industrial context. They are essential to the proper functioning of certain industries because of their combination of unique, but highly sought-after characteristics!

Its excellent mechanical properties, its different grades, its lightness, its durability and its ability to make work environments more "pleasant" (noise reduction) make it a material of choice for a large number of industries! It is because of these properties that nylon is generally used to substitute metals such as bronze and steel for various types of machined parts: Gears, bearings, etc.

The short story of nylon

Nylon 66 was first developed by Wallace H. Carothers while working for the DuPont de Nemours company in 1935. He discovered that the chemical reaction between acetylene and diacetylene led to the production of synthetic fibres similar to silk but much stronger and cheaper to produce.

It was in the textile industry that nylon was first used, but in the following years it was discovered that it could be used for mechanical plastic parts.

Nylon 6 and Nylon 66

What is a Nylon?

Nylon 6 and 66 are synthetic polymers called polyamides. Specifically, these are the two polyamides that compose the majority of industrial nylon materials. Their linear and regular molecular chains give them the following properties:

  • High mechanical strength, stiffness, hardness and bending strength.
  • High fatigue strength (damage to a part under varying loads)
  • Good mechanical damping capacity
  • Good sliding properties
  • Excellent wear resistance
  • Good electrical insulation properties
  • Good radiation resistance
  • Good machinability 
 
 What do the 6 and 66 mean?

These numbers represent the amount of carbon atoms you can find in the basic chemical compounds that are used to produce these nylons.

Example: Caprolactam (which is used to produce nylon 6) has 6 carbon atoms in its molecular chain.

Nylon 6 VS Nylon 66

Although these two materials are very similar on paper, there are some notable differences:

NYLON  6 NYLON 66
Lower mold shrinkage Presents greater mold shrinkage
Lower melting point Higher melting point
Lower thermal deflection temperature Higher thermal deflection temperature
Higher water absorption rate Lower water absorption rate
Lower acid resistance Higher acid resistance
Better impact resistance and hydrocarbon resistance Better stiffness
Glossy surface finish, easy to color Difficult to color

Thus, despite having common basic characteristics, these nylons differ in certain areas that must be considered when installing nylons in an industrial setting.

The key differences are in the water absorption rate and the thermal deflection temperature, where Nylon 66 has the upper hand. Nylon 6, however, has better resistance to hydrocarbons, impact and is better suited for precision part production.

To conclude...

Industrial Nylons are ideal candidates for innovation in your facilities and drive performance and growth for businesses.

Discover the different grades of Industrial Nylons such as MOS2®, NYLOIL® and many others by consulting the articles below:

  1. The advantages of choosing nylon machined parts

  2. The Applications and Advantages of High-Performance Nylons

  3. 5 Plastics with low coefficient of friction