The difference between PA66 and PA6

Both Polyamide 6 (PA6) and Polyamide 66 (PA66) are widely used in many different markets and applications due to their excellent performance / cost ratios. Many parts are made with these polyamides in the Transportation, Electronics & Electrical, Consumer goods, Building & Construction and Packaging industries. They are by far the most used Polyamides globally. Although they exhibit similar properties, slight differences do remain.

PA6 has a slightly lower temperature resistance versus PA66 and is also slightly less expansive.

Compared to PA66 the PA6 exhibits:

• Better hydrolytic stability

• Slightly lower cost

• Better long term heat ageing

• Slightly lower heat deflection temperature (PA66 HDT at 1.8 MPa is 80-90°C)

• Similar stiffness at temperature below 180°C

PA6, PA66 Applications

Agricultural Films		Medical Films		Liquid Packaging
Food Packaging		Sports		Furniture
Electrical & Electronics		Automotive		Protective Packaging

PA66 is used when PA6 reaches its limit temperature or when the hydrolytic stability of PA6 is not sufficient anymore. It provides good surface appearance and weld strength leading to burst pressure resistance.

The molding cycles are quick, providing an economical interest. Polyamide 6 and Polyamide 66 answer the requirements of numerous applications in the varied markets.

PA6, PA66 Automotive Applications

Thanks to their good processability, PA6 and PA66 are often used as an alternative to metal in automotive under the hood parts where design flexibility as well as temperature and chemical resistance are critical. They ultimately contribute to weight savings, which offers CO2 emissions reduction opportunities. PA66's mechanical properties (stiffness, creep resistance, etc.) helps improve safety and comfort in cars.

PA66 in Electrical & Electronics Applications

In the electrical and electronic applications where specific tests (GWIT, UL94) need to be passed, Polyamides 6 and 66, which can easily be flame retarded, are good candidates. Halogenated and non Halogenated FR solutions are commercially available. Moreover, they also bring solutions in this industry where miniaturization reinforces the needs for high temperature resistance and thin designs (possible due to easy processability). 

PA66 in Consumer and Industrial Goods

Polyamide 66 offers solutions for durable Consumer and Industrial Goods, thanks to its easy molding, colorability, nice surface aspect, and excellent mechanical resistance. PA66 is an excellent material when complex designs are needed, and it is also a cost efficient solution. 

Packaging Applications of PA6, PA66

PA6 and PA66 offer very high puncture resistance, barrier resistance to oxygen, carbon dioxide and aromas and transparency. All these properties make PA6, PA66 ideal for use in Packaging- Food packaging (mono or multi-layer).

For the furniture market, PA6, PA66 is used to manufacture stadium seats thanks to their brilliant surface quality, excellent resistance to dirt and ageing and offering a great alternative to polypropylene.

The exceptional fatigue properties and high impact and mechanical strength of PA6 and PA66 contribute in sports applications where they are used to manufacture Ski bindings.

this article was quoted from this website http://omnexus.specialchem.com/selection-guide/polyamides-state-of-the-art/pa6-pa66.