The set of mechanical properties of each raw polymer being generally unsuitable as it is for engineering applications, it is essential to upgrade and customize the raw materials by compounding before their use to satisfy the requirements of customers and applications. Fillers and reinforcement offer a broad range of opportunities from ground minerals up to sophisticated continuous fibres or honeycomb reinforced polymer composites.
Ground minerals or wood fillers such as chalk, china clay, talcum, wood flour and so on, have been used for a very long time. From a recent development, nanofillers and carbon nanotubes (CNT) with nanometric sizes and high aspect ratios lead to a high reinforcing effect at a low level but the processing, a key factor for a good efficiency, is difficult.
Using fibres is a well-established technique, the most popular being glass fibres broadly used under various forms, for example chopped ones dispersed into the matrix or continuous ones well ordered to customize the reinforcement.