Shielded electrothermal film is a kind of electrothermal film with integral metal shielding structure layer. As a kind of planar electrothermal material, electrothermal film is widely used in various occasions and environments that may be close to insulation plane, conductor plane and flammable and explosive environment. When it is applied to a conductive plane near concrete, metal plate, etc. The conductive surface will naturally form a capacitor structure with the heating part and insulation part of the electrothermal film, and the conductive surface and the heating surface will become the two plates of the plate capacitor. When the electrothermal film works, due to the existence of this capacitor structure, the alternating current passing through the electrothermal film naturally forms a weak charge drift on the earth, which is called leakage current in electricity. The leakage current is directly proportional to the square of the contact area between the electrothermal film and the conductive plane, inversely proportional to the distance between the electrothermal film and the conductive plane, and directly proportional to the working voltage of the electrothermal film. Generally speaking, the existence of this leakage current will not bring hidden dangers to the safety of electricity consumption, nor will it affect the work of electric heating film. However, when this structure exceeds a certain area (about 15㎡), it will cause the leakage protector in the working circuit of the electric heating film to act and make the electric heating film unable to work. At this time, the leakage protector can only be forced to pass through to make the electric heating film work normally, which obviously does not meet the safety regulations. The insulating layer of Baoheng electrothermal film is compounded with metal foil to become the shielding layer of electrothermal film. The shielding structure can completely shield the leakage current and make the electrical system safe. In addition, when the electrothermal film is used in flammable and explosive environment, the shielding structure can also prevent the generation of static electricity and sparks, ensure safety, and obtain the approval of safety regulations (explosion-proof certification).
In the domestic electric heating film industry, Baoheng electric heating film pioneered the shielding structure and integrated design. The shielding layer is embedded in the insulating layer, which is closely combined, convenient to install or lay, and has better shielding effect, and does not affect the heat dissipation and radiation ability of the electrothermal film at all.