The heating materials are graphite, metal powder and metal oxide. The production process of carbon based ink electrothermal film is to make the above-mentioned heating materials together with other fillers into ink-like slurry, and to quantitatively print on the polyester film with metal current carrying strip (as electrode) in advance by screen printing process, and then cover the polyester film to form the insulation structure, so it is also called printing ink electrothermal film. The power control of carbon based ink electrothermal film is mainly realized by the size composition, ink strip thickness and spacing.
The core of electrothermal film of printing ink is the production and processing technology of size. It is characterized by simple production process, relatively low cost of raw materials and large degree of localization. At present, there are many domestic enterprises producing carbon based ink slurry and more than a dozen manufacturers of carbon based ink electrothermal film. The production and processing technology has caught up with and surpassed the foreign counterparts.
2. Metal based electrothermal film
The heating material is pure metal or metal alloy material. The production process of the metal electrothermal film is to make the metal foil of the heating body metal or metal alloy material first, and then make the resistance circuit by bonding on the polyester film, and then cover the polyester film to form the insulation structure. Commonly used metal electric heating materials are nickel, copper nickel, iron chromium aluminum, etc. Different metal and metal alloy materials have different resistivity, that is, conductivity. According to different working voltage and unit area power requirements, different metal heating materials can be selected and different resistance circuits can be designed. The difference of metal materials will directly affect the performance and cost of the heat generator.