What Is a Film Heater?
A film heater is a type of surface heating element that utilizes resistance heating of metal. This heater features a very thin metal heating element, insulated between films. The structure of a film heater allows for ultra-thinness and flexibility, which were not achievable with traditional heaters. It has recently become popular in various industrial fields, with its performance being enhanced by the type of insulating film used. Additionally, the simplicity of its structure makes film heaters relatively inexpensive.
Uses of Film Heaters
Film heaters are versatile and used for heating small tanks and containers, creating heat plates sandwiched between metal plates, and in snow-melting applications for equipment like antennas and outdoor sensors. They are effective in preventing the freezing of outdoor piping and are also utilized in spot heating devices, local temperature control in animal breeding, and more. Film heaters with ITO (indium tin oxide) evaporated heating elements are used for seat heating in vehicles like cars, trains, and airplanes. They are also employed for snow melting and anti-fogging in cockpit windows of various transportation modes.
Principle of Film Heaters
Film heaters use a thin foil of aluminum, stainless steel, copper, or similar materials as heating elements. These foils, ranging from 10 to 50 μm, are etched or die-cut into specific patterns and then sandwiched between resin films for insulation. The heating capacity is determined by the pattern’s total length, cross-sectional area, and material resistance. Voltage is applied through terminals at the start and end points of the pattern, where lead wires are attached. Various films like polyimide film, PET film, or fluoroplastic film are used for insulation, chosen based on the application and environmental requirements. The design flexibility of the heating pattern allows customization to specific areas and shapes. The film’s low thermal capacity facilitates rapid temperature changes, but the thin heating element and the insulating film’s heat resistance limit the maximum operating temperature.