Polyamide – PA

Polyamide – PA

Those with advanced technical requirements for their components and materials need not look much further than polyamide for the solution. The process used during its production wields a significant influence on its properties, enabling a potential range of characteristics – from high transparency to toughness to high tensile strength – that is virtually unmatched by any other material. This blog entry leaves aside the discussion of special modifications (with reinforcing materials such as carbon fibres) or the addition of internal glide and demoulding additives to describe a few of its basic characteristics.

What is PA?

Polyamide is a semi-crystalline, predominantly linear polymer. A distinction is made at the production stage between condensation polymers and ionic polymers.

How is polyamide produced?

Categorisation of polyamide types occurs on the basis of numerical data pertaining to the number of carbon atoms relative to the number of hydrogen atoms in the chain. Polyamide 6.6, for example, is produced from hexamethylendiamine and adipic acid. Polyamide 6 is formed from a ring-opening polymerisation of caprolactam. Precise classification takes place according to the type of monomers, the monomer composition and the setting behaviour. Other commonly used polymers are PA 12, PA 10, PA 4.6 and PA 6.12.

Why is polyamide used?

The various production processes for polyamide enable certain of its characteristics to be changed. The frequency with which the amide group is repeated along the length of the polyamide chain determines the strength of the intermolecular binding forces and the water absorption properties, the latter of which affords the polyamide its quality of toughness. Outstanding properties of polyamide include:

– High dimensional stability at high temperatures
– High impact resistance
– Excellent gliding properties
– High abrasion resistance
– Very good chemical resistance (except in the case of exposure to concentrated formic acid)
– High permeation resistance
– Minimal evidence of fatigue with long-term use

How is polyamide processed?

As with other thermoplastic materials, processing methods for polyamide rely predominantly on injection moulding, extrusion moulding and blow moulding techniques. The degree of crystallisation can be increased significantly through the choice of processing method, which in turn improves certain other basic characteristics.

What are the applications for which PA is particularly well suited?

Polyamide’s excellent technical properties render it suitable for application in:

– Gear wheels, castors, nuts, slide bearings,
– housing for electrical appliances, bobbins,
– cranks, fan wheels, covers, fluid containers,
– fittings, dowels, hinges,
– composite films, hollow parts,
– bristles and cords.

Need a special modification?

We supply polyamide within made-to-measure product solutions. Contact us for more information!