Each raw polymer has its set of properties being generally unsuitable as it is for engineering applications. It is essential to upgrade and customize the raw thermoplastics by compounding before their use to satisfy the requirements of customers and applications. Numerous additives are marketed, each enhancing one or several specific properties. Unfortunately other characteristics can also be deteriorated and it is necessary to carefully study the better balance between all the properties.
For aesthetics and durability, surface modification by painting, film covering, metallization, surface treatments are also suitable to complete the whole range of additives.
Sensorial properties are more and more important to differentiate a product at a glance and all the criteria are significant: colour, gloss, odour, soft touch, flexibility...
The producer brings certain improvements but others are implemented by compounders or by the converter himself.
For engineering applications, the thermoplastics must have a set of properties concerning:
* The original characteristics: aspect, mechanical, electrical, optical performances