Caution! Hot surfaces - Thermally sprayed heaters

Temperature control is crucial in many manufacturing processes to assure high quality products. While conventional heating systems are typically slow, take up large construction space or require additional process steps, coating technology may represent a more efficient alternative. With a thermally sprayed coating system heat can be brought in exactly, where it is required, while adding only a few hundreds of microns to the machine parts. Therefore, high heating rates can be achieved. A ceramic based heating layer was investigated in laboratory as well as field tests. With dynamic thermo-cycling and direct application in a plastic injection mould, the coating’s capability for such range of application was demonstrated. A homogeneous temperature distribution, high heating rates of more than 25 K/s for several 10,000 thermo-cycles and process independent controllability were observed. Considering the presented development, thermally sprayed heating coatings exhibit a hitherto unexplored auspicious alternative not only for plastics processing, but also for other applications like furnaces or rollers, where efficient surface heating is required.