Mineral fillers are additives that – once mixed with a polymer – do not dissolve, but remain in a separate phase. The material obtained is a composite, which may have new properties if compared to the raw polymer:

• Enhanced mechanical properties 
• Enhanced physical properties  
• Enhanced dimensional stability 
• Lower costs

To obtain good composite properties, the compounding process plays a key role. As a matter of fact, it is important to achieve the proper filler dispersion preserving the polymer properties.
This is possible through an optimization of:

– filler feeding scheme – screw profile
– temperature profile
– formulation
– quality of raw materials

However, we should not forget the role played by all additives. Chemicals must be studied and defined to improve the mixing efficiency and the final compound quality. This makes it vital to preserve their stability throughout the process.

Chemicals must be studied and defined to improve the mixing efficiency and the final compound quality. This makes it vital to preserve their stability throughout the process. But it is important to underline composite properties strongly depend on the mineral particles properties:

• Geometrical properties (Aspect ratio)
• Chemical properties
• Physical properties