Definition and general information
Flat electric heating elements are designed for heating flat metal surfaces, such as tooling, heating tables or trays, and molds. They can also be used for indirect heating of liquids or powdery products contained in tanks, by being fixed under the bottom or outer walls.
They are widely used in various industrial sectors (plastics, food processing, chemicals, etc.), notably for heating press platens, maintaining the temperature of products stored in tanks, or heating molds during the manufacture of composite parts.
Heat is transferred mainly by conduction, whether when the flat resistor is applied to a metal part, or when heating a product through the walls or bottom of a container. This heating method ensures even, rapid and efficient heat distribution.
Vulcanic offers two technologies:
- Shielded mica flat resistors consist of a resistive heating ribbon wound on a mica insulating plate. The whole assembly is protected by a sheet steel or stainless steel shield, which ensures both mechanical protection and good heat transfer by conduction to the surface to be heated.
Thin (3 to 4 mm), flat mica resistors have a maximum operating temperature of 300°C and a maximum load of 4.2 W/cm2.
- Shielded ceramic flat resistors incorporate a coiled resistance wire mounted in ceramic insulating elements. This is then covered with a stainless steel shield.
They can be used up to temperatures of 700°C with loads of 6.5 to 8 W/cm2.
Electrical connection can be via threaded terminals or direct cable outlet, depending on the application and installation constraints.
Rectangular or round, resistors can be manufactured in specific shapes, depending on the technology used. They can incorporate holes for mounting, probe passage, or the addition of pipe tappings.
External mounting allows quick access to the resistor, facilitating replacement without dismantling the system or prolonging production downtime.
- Unit power from 200 W to 2000 W.
- Single-phase voltage 230 V.
- Maximum operating temperature: 300 to 700°C depending on technology
Applications
Flat resistors are used in many applications. Here are just a few examples:
Aeronautics
In the aerospace sector, composite materials are commonly used to manufacture lightweight, high-strength parts. Flat heating elements are integrated into the forming molds to ensure controlled, even heating during the polymerization cycle.
Food industry
In food production units, flat heating elements are used to indirectly heat tanks containing products. Installed on the outer walls of the tanks, they enable a stable temperature to be maintained without direct contact with the product.
Chemistry and pharmaceuticals
In the laboratory, flat resistors are integrated into thermal or stability testing devices. Mounted under metal plates, they provide uniform, precise heating, essential for simulating controlled temperature conditions.
Energy sector
In rubber processing plants, flat heaters are mounted on the platens of presses used for vulcanization. Their role is to provide a stable, even temperature across the entire molding surface, to ensure proper rubber polymerization.
Technical data
Flat heating elements consist of :
- Heating ribbon or resistive wire
- Insulating elements in mica paper or ceramic, depending on the model
- External steel or stainless steel shielding plate
- Electrical connection is via threaded terminals or directly via cables.
Further information
- Flat resistors are not suitable for ATEX environments.
- In addition to the wide range of finished products shown in our online catalog, Vulcanic is able to design custom-made equipment, manufactured on demand to meet your needs (power, voltage, specific shapes...).
Recommendations
Precautions for use
Flat resistors must be perfectly flat against the part to be heated to ensure correct operation and long service life.
Installation and connection
If the flat resistor has no holes for mounting, use a counterplate to clamp it to the workpiece.
Please refer to the instruction manual for all recommendations relating to the equipment.
