Silicone Oils | Kinematic Viscosity of Silicone Oils

Silicone oils provide a lot of unique properties such as thermal stability, wide operational temperature range, a very high viscosity index, low surface tension and chemical inertness to list only a few of them.

They are used e.g. as lubricants, damping oils, hydraulic oils, heat transfer oils and additives in plastics. Nearly all branches of industries use them, e.g. cosmetic, pharmaceutical, textile, food, glass, wood, metalworking industry and many more.

For all these different applications, viscosity plays a major role. The correct viscosity ensures e.g. optimum heat transfer, quick response of brake pedal and pistons or valves within a brake system over a large temperature range, smooth dispersion of the liquid on surfaces, best lubrication properties. A change of viscosity can also indicate a change or degradation of the oil.

Usually, kinematic viscosity and density of silicone oils are specified at 25 °C. Depending on their intended use, viscosity and density are often stated at the temperatures at which the material is used, e.g. at 40 °C or, for brake fluid, even at -40 °C. Furthermore, the viscosity index and for some applications also the refractive index at 20 °C or 25 °C (especially for pharma) are of interest. Some manufacturers also state Saybolt viscosity.