Hoffmann Mineral: New fillers on basis of calcined siliceous earth

At the K show, Hoffmann Mineral GmbH will present its product portfolio expanded by newly developed calcined products. Motivated by the high market demand for alternative fillers against calcined clay or wollastonite, the company now offers three different types of calcined Neuburg siliceous earth: Silfit Z 91, Aktifit AM and Aktifit VM.

While Silfit Z 91 is an untreated basic product, the surface-coated type Aktifit AM comes with an amino and Aktifit VM with a vinyl functionality. With Aktifit AM the company offers for the first time a well fitting product for thermoplastic applications. Fillers in thermoplastic polymers are decisive to reach those high requirements, which cannot be gained by an unfilled matrix. Further information on the new calcined products will be presented for the first time at the K show.

Furthermore, Hoffmann Mineral will showcase the new surface-treated siliceous earth Aktisil Q. The company has recently developed this functional filler especially for the application in HCR silicone rubber. Aktisil Q can be used as functional filler either on its own or in combination with other non-reinforcing or reinforcing fillers. The best effect is achieved in radical-cured systems (peroxide, high energy radiation). Aktisil Q should be used where high tensile strength and moduli along with very low tensile and compression set are of importance as well as excellent processing properties and high oil resistance. These effects offer an ideal combination in particular for moulded articles with high requirements as to tensile and compression set.

Furthermore, blooming of crosslinker or reaction products of bis-(2.4-dichlorbenzoyl)-peroxide can be avoided. Even more, the extrusion of silicone rubber profiles and hoses containing Aktisil Q will result in products with excellent surface quality, reduced stickiness, very smooth edges of profiles and high collapse resistance, compared to the use of surface treated quartz flour.