The range of processes used in plastics processing can now processed using infrared heating technology. So says the team at Heraeus Noblelight, Gaithersburg, Md., which notes that infrared emitters are already well established in the rapid, homogenous heating of large, flat surfaces. There is a real challenge in manufacturing processes where only very small or curved surfaces, edges, borders or defined contours of the product need to be heated. Why is it necessary to heat up complete car doors, steering wheels or foot mats when only a few centimeters of these products require heat?

Heraeus makes its point by citing several common materials in automotive manufacturing.

• Car carpets generally consist of a polyester topside with a rubber underside. The underside is made non-slip by means of pimples or similar structures. The topside fleece can fray after the mats are cut to size, and conventionally, edges are crimped with a heated tool to prevent this. By using infrared emitters, it is no longer necessary to pre-heat the tool. An emitter, which is shaped exactly to the shape of the carpet edge, heats this edge in seconds before the edge is crimped by the crimping tool. This contact-free infrared heating, using precisely shaped emitters, can reduce production cycle times to 15 to 20 seconds. Quartz glass infrared emitters can be used in the production of edges and borders. They apply heat so precisely, exactly where it is needed, without heating the rest of the foot mat. This minimizes heating damage and saves energy.
• Plastic components can be joined by infrared heating without the need for adhesives or other joining mechanisms. The infrared radiation melts a thin surface layer of the individual plastic parts in a short time. The parts are then joined by simply pressing them together to form products such brake-fluid reservoirs. In contrast with contact welding using hot plates, no excess material clings to the heat source and the heating stage takes place in seconds and is repeatable.
• Plastic handles, housing parts, air intakes or covers are often injection molded. Very often it is impossible to prevent the creation of sharp-edged burrs, especially in the tool separation plane. Shaped infrared emitters precisely melt away only the burr, without damaging the actual work piece. As a result, they are superior to many conventional methods, such as manual removal with special blades or by the use of gas flames, which do not produce repeatable results and take considerable time.

Hereaus Noblelight has experience applying energy efficiently even for difficult manufacturing operations.