Processing Magazine

High Temperature Paint Surpasses Solar Coating Technical Tests

February 21, 2013

pyromarkA recent series of solar coating technical tests of Tempil’s Pyromark 2500 confirms its superb absorptivity/emissitvity properties, and long lasting protection in solar applications.

The tests show that silicon based coatings help prevent oxidation, corrosion, and abrasion. At maximum heat temperatures they do not blister, crack or peel.

The Pyromark 2500 coating helps heat by radiation through the “blackbody” effect. The blackbody is defined as a material which emits the maximum amount of radiation at a given temperature. Materials which are good radiators (absorbers) and approximate blackbody characteristics are carbon, asbestos, and rubber. Highly polished metals are poor blackbodies and therefore good reflectors. The best radiator, a perfect blackbody, exhibits an emissivity of 1.0. Pyromark 2500 has been proven to have very high emissivity and absorptivity values (more than 0.95) which are very attractive properties especially for the solar industry. It can be applied on mild steel, stainless steel, aluminum, inconel, aluminized steel and ceramics. 

In addition, the thermo-optical properties of Pyromark° flat black coatings make them ideally suited for applications to improve the radiative heat transfer of infra-red heaters and to increase the heat gain of solar absorbers.

The Tempil coating may be applied by spray or brush with air and surface temperatures between 50°F (10°C) and 90°F (32°C).

Controlled vitrification is the key to the very high temperature service capability of the coatings. In effect, vitrification converts the 100 percent silicone resins to inorganic silica producing a thin, but tenacious, refractory coating which will withstand higher temperatures than most conventional coatings.