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Low abrasion
talc is the softest of all minerals with a Moh´s hardness of 1. But only pure, chlorite-free talcs, give the low abrasion values which lead to a long tool life in compounding and extrusion.
Colour consistency
PP compounds are pigmented in a large variety of colours. To ensure reproducible colour shades, the colour of the talc should show as little variation as possible. Flotated Finntalcs are most tightly controlled and give a significant benefit to formulators.
Creep resistance
Creep is the deformation of pipes under load (e. g. under soil) over a long period of time. Pure, platy talc leads to superior creep resistance compared to other fillers.
Oxygen barrier
In polyolefine food packaging, talc reduces oxygen and water vapour transmission. Pure, chlorite-free talcs are chemically inert and can fulfil the anti-migration requirements of EN 1186.
Stiffness (E-Modulus)
The main function of talc in polymer compounds is to increase the E-modulus. talcs with high aspect ratio are the most efficient.
Thermal conductivity
talc/polyolefine compounds have a significant higher thermal conductivity than the virgin polymer. Heating and cooling are shorter, resulting in faster production rates.
Impact strength
A loading of up to 10% of a fine, pure platy talc like Finntalc M05SL can increase stiffness and impact strength of polypropylene compounds at the same time.
Nucleation
Fine talcs with a median particle diameter of 2 µm very efficiently promote the crystallisation of polypropylene, leading to improved impact strength.
Heat aging resistance
Magnetic impurities like soluble iron oxide are removed by electromagnetic separation in the purification for Finntalc SL grades. Iron, which is incorporated in the talc crystal (replacing Mg atoms), is inactive and does not have a negative effect on the heat distortion temperature.
Scratch resistance
Pure, soft talc leads to a better slip of scratching objects. Greyish talc reduces the visibility of scratches.
Reinforcement of rubber
The micro-crystalline Extrafil talc grades with high specific surface area improve mechanical properties of rubber compounds, at the same time reducing gas permeability and electrical conductivity.
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