What is a mineral filler ?

Mineral filler : definition

Mineral fillers are mineral constituents incorporated into a binder in order to improve the characteristics of the final manufactured products. These mineral fillers are of varied nature (kaolinite, talc, calcite, micas, baryte, silica, aggregate, etc...) and widely used in industrial fields as diverse as stationery, paints, plastics, rubbers, agro-food, construction, etc...

The incorporation of mineral fillers makes it possible to modify one or more characteristics of the finished product : its physical properties, its thermal resistance, its conductivity, its abrasiveness, its density, its color, its opacity, the bonds between the particles and their binder, or yet to solve manufacturing problems. This is the first step towards composite materials, as products incorporating mineral fillers are considered by some scientists to be composites in their own right. However, it is common for improving one property to degrade another, which is why it is common to combine several mineral fillers in order to optimize the qualities of the product.

Carbonate fillers (composed of calcite) are frequently chosen because of their physicochemical qualities (whiteness, relative chemical inertness, average hardness and density), but also for their low price and their wide distribution. In the field of mineral fillers, the consumption of pulverized calcium carbonates is constantly increasing : they replace mainly talc and kaolin.