Emisshield® Products are based on the Protective Ceramic Coating (PCC) Technology developed by NASA for the heat shield of the X-33 and X-34. Extensive research was done by the NASA scientists to develop the best high emissivity coating possible in order to protect people and equipment from re-entry conditions
(-215F – 3000F).  Research scientists of Wessex Inc made further modifications and developments to create Emisshield® Products – high emissivity nanoparticle ceramic coatings.

All substrates have an emissivity value that is reported as range from 0.0 to 1.0. A black body is a theoretical substrate with an emissivity of 1.0 where 100% of thermal energy absorbed is then emitted. Emisshield® Products are grey bodies as they emit a portion of the thermal energy absorbed consistently across temperature and wavelength.


Many substrates report high emissivity values at ambient temperatures.  However, their emissivity values will not remain the same over a range of temperatures which makes them non-grey bodies.  The physical characteristics of most non-grey bodies limit their temperature capabilities. Emisshield® Products are comprised of a complex ceramic nanoparticle matrix that allows consistent performance at temperatures up to and over 3000F.

An equation can be used to theoretically predict the amount of energy a substrate’s surface can reradiate based on its emissivity:

Where:              Q is measured in units of Btu/hour-ft2
                        Ew = emissivity of substrate’s surface
                        σ = Stefan-Boltzman Constant
                        Ts = surface temperature
                        Tsur = surrounding temperatures

This formula shows that emissivity is a function of temperature in that as the temperatures rise, the reradiation potential increases. And as temperatures fluctuate, Emisshield® Products maintain their emissivity values of 0.85 -0.95 and offer much more reradiation predictability and capability. 

The emissivity of Emisshield® ST-2 was measured using the same test method utilized by NASA. The other Emisshield® Products have similar graphs when measruing emissivity illustrating that the Emisshield® Products are true grey bodies.

Please contact Wessex Inc for further information on emissivity and how Emisshield® Products can improve your thermal processes.