The DJR-720 spring coil heater uses a helical spring structure, employing elastic tension to make the coil body fit tightly against the outer wall of the part being heated. During thermal expansion and contraction, it can automatically compensate for gaps and maintain stable heat transfer contact. This structure is suitable for hot runner systems, injection molding machine nozzles, extruder hot tips, and other heating locations with limited space that require quick installation and removal. The maximum operating temperature can reach 650°C, and the maximum power density is 9 W/cm².
Compared with ceramic coil heaters, spring coil heaters do not require custom irregular cast parts and offer better adaptability to the outer walls of bodies of revolution such as cylindrical and conical surfaces. During installation, they are secured by their own elastic force, reducing the use of clamps and fasteners. Compared with cast aluminum coil heaters, the spring structure is less prone to permanent deformation under repeated disassembly and assembly conditions, making maintenance and replacement more convenient. It should be noted that electromagnetic induction coil heaters can also be used in similar scenarios, but their working principle differs from that of resistance-type heaters. During design and selection, a comprehensive judgment should be made based on the heating method, temperature control accuracy, and on-site power supply conditions.
Design and selection personnel should first confirm the diameter and effective heating length of the part to be heated, and determine the inner diameter and number of turns of the coil body accordingly. Second, check the operating voltage and power density to avoid local thermal loads exceeding the allowable range of the material. For hot runner systems, attention should also be paid to the lead wire outlet direction and temperature resistance grade to ensure matching with the mold space. In the heating sections of chemical fiber, rubber, and packaging machinery, corresponding specifications can be selected according to the cylinder size.
This product is commonly used in injection molding machine nozzles, extruder hot tips, hot runner manifold plates, and other locations. During installation, ensure that the coil body fits evenly against the outer wall of the part to avoid uneven heat dissipation caused by local suspension. The lead wire section should be kept away from high-temperature areas and properly insulated. Regularly check the spring tension status to maintain long-term stable heating performance.
