Additives enhance properties of polymers to allow more stringent engineering applications. The improvement must concern any particular property such as, for example:
* Aesthetics, mechanical, thermal, electrical, optical performances…
* Ease of processing, moulding, extrusion etc, accuracy of shaping…
* Ageing (heat, sunlight, weathering, hydrolysis…), creep, relaxation, fatigue…
* The cost
Everybody says that the enhancement level obtained from the use of a precise amount of a well defined additive is not identical in different situations depending on the used polymer, accuracy of dosage and compounding methods…
Beside this theoretical point of view it is necessary to answer several questions:
* What are the problems?
* What are the possible actions of the compounder?
* Is the game worth the candle?
* Is it possible to obtain synergistic effects between additives
What are the problems?
Additives are used to improve the compound performance but are also related to the environment.