Calcium carbonates
Calcium carbonates are composed of the crystalline mineral, calcite, which occurs naturally in the form of chalk, limestone or marble. Calcium carbonate is the most significant filler nowadays and one of the most widespread binders on earth. Calcium carbonates are used in many plastic applications in order to ameliorate the mechanical, rheological and optical properties. Calcium carbonates can be processed by crushing and fractionation to suit almost all applications. Some product forms undergo a surface treatment with a stearate ameliorating the processing and the dispersion. A good dispersibility and a high degree of whiteness combined with positive mineral properties make the use of calcium carbonate as ecological filler inoffensive. It suits perfectly to applications in plasters, adhesives, PVC, polyolefins, elastomers and thermosets.
Dolomite
Dolomite is a calcium magnesium carbonate. Its colours reach from white, grey, yellowish to red brown. The colour red brown is a sign of strong alteration. Dolomite is composed of calcite and fine grained sediment. It is used as filler in plastics and paints. The construction materials industry uses it as additive for wet mix aggregate, as filler for bitumen and concrete, as bulking material and filler for plasters, road construction materials and cement row materials.
Kaolin
Calcined kaolins are produced by heating natural kaolin (China Clay) to high temperatures (ca. 1000°C). They are used as fillers in the plastic industry and also in rubbers, sealants and adhesives. Fully calcined kaolin can be coated with silane in order to obtain a surface that chemically bounds with the polymer. Due to its properties like a high chemical resistance, kaolin has many special applications.
