Thick film heating elements are manufactured in a completely different way than ordinary tubular heating elements. A thick film heating element consists of a stainless steel substrate (plate), on which an insulation layer (meets the requirements for dielectric strength) is printed, then a layer of resistive paste, followed by a contact and connective layer, and finally all these layers are covered with top insulation layer (providing protection against mechanical damage). The individual layers are applied by screen printing and each layer is dried and fired afterwards. Maximum protection from dirt and dust is essential through the whole production process. Production runs are in air-conditioned areas meeting the requirements for rooms with high air purity class.
Thus precisely manufactured thick film heating elements feature a quick temperature rise, an extremely low thermal capacity and minimum temperature fluctuations. Their high efficiency of 70 - 95 % depends on the mode of operation (direct or indirect heating).
The substrates are made of stainless steel according to standards AISI 430 (DIN 1.4016), AISI 304 (DIN 1.4301), AISI 444 (DIN 1.4521) and Titan Grade 2 (DIN 3.7035) are used. The substrate (printing area) must be flat, but can be of various shapes and can contain openings manufactured in advance (before the printing process) if required.