^{TREMIN® 939}

Wollastonite a natural calcium silicate that is formed when silicon dioxide and calcium carbonate are fused at a temperature of approx. 450°C. The structure of the individual wollastonite particles depends on their geological origin on the one hand, and on the other it is determined largely by the processing technologies used to refine it. Using specific processing technologies wollastonite powders with particle structures from nearly block-like with a low aspect ratio (LAR) about 3:1 (TREMIN 283^®-product series) to exceptional acicular with a high aspect ratio (HAR) about 8:1 (TREMIN 939^®-product series) are achieved.

 Features
• High degree of whiteness (Y > 90)
• Density 2.85 g/cm3
• Hardness of 4.5 (Mohs)
• Low thermal expansion coefficient: 7*10^-6 K^-1 (at temperatures of 20-300°C)
• TREMIN® 939 products: needle-shaped particles (L/D: 8:1) HAR
• TREMIN® 283 products: block-shaped particles (L/D: 3:1) LAR
• Excellent reinforcement characteristics

Key applications
• Plastic parts made of PP, PA or PUR RRIM compounds for the automotive industry
• Engineering thermoplastics made of PA, PBT or POM
• Fluoro silicone e.g. for oil seal
• Friction linings
• Powder coatings
• Anti-corrosion coatings

_{^{TREMIN® 283}}