The Universal Selection Source: Plastics & Elastomers

Selection Guide

Techno Brief: Polyamides

Exhibiting high temperature and electrical resistances, polyamides (nylon) are considered as high performance plastics and are widely used in automotive & transportation markets, in consumer goods and in electrical and electronics applications among others. This guide details the main applications and benefits of some common polyamides: PA11, PA12, PA46, PA6, PA66 and PPA (polyphtalamides).

Polyamides Overview

Polyamides Generic Properties

Polyamides are one of the major engineering and high performance plastics because of their good balance of properties. They exhibit high temperature and electrical resistances. Thanks to their crystalline structure they also show excellent chemical resistance. Polyamides have very good mechanical and barrier properties. In addition, these materials can easily be flame retarded.

Polyamides Applications

Polyamides are widely used in markets such as Automotive & Transportation, Electrical and Electronics, Consumer Goods to name a few. When reinforced with glass fibers (short or long), their stiffness can compete with metals, this is why Polyamides are often considered in metal replacement projects.

polyamides in automotive applications polyamides in packaging Polyamide in furniture parts polyamides in communication parts polyamides in electrical and electronics applications

Some well-known Polyamides:

Among this large polymer family, several types of polyamides are particularly suited for given applications. The best choice depends on the set of performances needed as well as the economical constraints. The two most widely used PA are by far the PA6.6, also known as Nylon and the PA6. They are often extruded to manufacture fibers (textile industry) or films (packaging), or injected.

The Polyamides with the highest performances are PPA and PA4.6, which are good candidates for metal replacement developments or very specific applications exposed to extreme conditions.

Biobased PA are also available. For instance, PA11 is based on castor-oil chemistry.
Discover the key benefits and the differences of various Polyamides by clicking on the links below:
PA6 and PA66 cost effective and good processability PA11 and PA12 remarkable long lasting performances polyphtalamides demonstrate excellent retention of performances in a wide range of conditions PA46 extreme temperature resistance and excellent friction properties

However all Polyamides tend to absorb moisture due to the amide chemical group. Moisture acts as a plasticizer on Polyamides thus reducing tensile modulus and increasing impact resistance. This is why a particular care should be taken when reviewing polyamides technical data sheets (data split into "dry" and "at 50% RH" categories). Moisture uptake also has a huge influence on dimensional variations; this must be taken into account when designing parts.


Polyamides Processing

Thanks to their crystalline structure Polyamides are easy to inject, showing high fluidity. This is particularly appreciated when injecting thin-walled parts.

Due to their moisture sensitivity, Polyamides require efficient drying process. Insufficient drying will lead to splays and unaesthetic marks on part surfaces, as well as lower mechanical properties due to material degradation (heat and water lead to oxidation).
PA6 and PA66 cost effective and good processability PA46 extreme temperature resistance and excellent friction properties PA11 and PA12 remarkable long lasting performances polyphtalamides demonstrate excellent retention of performances in a wide range of conditions

PolyOne webinar on sustainable automotive lightweighting
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