Mica heaters are “open” heating elements. If a higher ingress protection class and greater mechanical strength are preferred, the mica heaters must be sheathed in a suitable metal material, such as electrogalvanised sheet metal or stainless-steel.
Shielded mica heaters can withstand a higher load than mica heaters. Under normal operating conditions, we recommend a maximum surface load of 5 W/cm2 for shielded mica heaters.
Read more about the potential uses of mica heaters and shielded mica heaters and get the technical details here: