Advantage for thermal properties

AEROXIDE® in flexible and temperature-stable food molds

AEROXIDE^® fumed silica plays an important role as an active reinforcing component in food molds made of silicone rubber, such as ice-cube trays or cake molds. Excellent thermal properties such as lowtemperature flexibility and heat resistance are obtained by the use of AEROXID^® products or special heat stabilizers.

Silicone rubber ice-cube trays retain their flexibility even at temperatures as low as -40 °C, making it very easy to remove the ice cubes from the tray without damaging it.

Cake molds of silicone rubber, on the other hand, are heat-resistant up to 280 °C, non-slip and completely dishwasher safe. No non-stick coating or greasing of the mold is necessary because the batter does not adhere to the elastic silicone mold. And the silicone material results in energy savings of 10 to 20 percent.

Food molds can be made from solid or liquid silicones, which may be ready-to-use HTV or LSR Silicone Rubber. These are one-component or two-component systems of a highly viscous or free-flowing consistency, which are fully cured to an elastic silicone rubber under the action of specially tailored crosslinkercatalyst systems at processing temperatures above 100 °C.

AEROSIL^® fumed silica imparts the necessary rheological, mechanical and optical properties to the silicone rubber. Evonik offers two special oxides for silicone rubber, AEROXIDE^® TiO₂ P 25 and AEROXIDE^® TiO₂ PF 2, as heat stabilizers for high-temperature applications.

AEROSIL® in and around the automobile

Silicone systems such as silicone sealants with AEROSIL^® fumed silica as active component are now indispensable also in automotive construction. Whether in the engine, the drive system, the cooling system, the electronics or the body, silicones, with their exceptional and highly specific properties, have already overtaken more conventional materials.

For sealing engine segments, for example, RTV one-component silicone rubber is particularly suitable because they retain their elasticity even on long-term exposure to temperatures of up to 250°C.

Bild und caption: Silicone gaskets play an important role in automotive construction. These systems are particularly well suited for sealing of, for example, engine segments: Thanks to AEROSIL^® fumed silica they retain their elasticity even during long-term exposure to temperatures of up to 250°C

The FIPG (formed in place gasket) process is often used here, in which the Silicone Rubber is applied from a dosing head that traces the computer-programmed contour of the product part to be sealed, in the manner of a template.

RTV one-component systems are ready-to-use single-component systems of a free-flowing or soft paste consistency that are fully cured to an elastic Silicone Rubber under the effect of atmospheric humidity at room temperature. AEROSIL^® fumed silica lends the silicone rubber the necessary rheological and mechanical properties.

Percent change of elongation at break for HTV silicone rubber after storage at 275 °C*