PA (polyamide)

Polyamides are semi-crystalline polymers.

Basically, a distinction is made between two types. Polyamides built up from two basic materials (e.g. PA 6.6 and PA 4.6) and polyamides built up from one basic material (e.g. PA 6 and PA 12). Polyamides have very good mechanical properties, particularly high toughness and excellent sliding and wear behavior. The properties vary from hard and tough PA 6.6 to soft and flexible PA 12.

In the manufacture of semi-finished products, a distinction is made between the extrusion and casting processes. In the casting process, polyamide semi-finished products with larger dimensions and a higher degree of crystallization (mechanical strength) can be produced, which also contain less internal stress. The extrusion process, on the other hand, enables more cost-effective production. Depending on the type, polyamides absorb different amounts of moisture, which affects both the mechanical properties and the dimensional stability.

Polyamides can absorb up to 7% of their weight in water at high humidity or when stored in water. This can result in a size change of up to 2% and a corresponding deterioration in the physical properties of the material. This effect must be taken into account in the design and when determining the tolerances. We will be happy to advise you on the selection of the right material for your application.