The internal paneling of motor vehicles must fit perfectly, the containers for brake fluid and screen wash must be sealed and the steering wheel should have no sharp edges. The plastic parts used for these are riveted, welded or deburred. Contour-matched infrared emitters help to carry out these operations reliably, even on difficult corners or edges. A newly developed Spotlight emitter from Heraeus Noblelight, transfers heat in a targeted fashion to locations which are difficult to access, with a diameter of only 5mm. Especially difficult processes can now be so automated that rejects can be significantly reduced compared with manual methods. Applying heat precisely where it is required and for as long as is absolutely necessary saves both energy and costs.
Spotlight Infrared Emitter
The Spotlight emitter supplies energy of up to 500 kW/m² and can direct this energy onto surfaces of just 5mm diameter. It does this without the need for lenses or complicated reflector systems, unlike conventional emitters and also without the need for elaborate safety precautions, as are required with lasers.
Consequently, the Spotlight emitter is ideally suited for deburring, riveting and welding plastic components in particularly difficult locations or locations which are hard to access. The emitters respond extremely quickly to control commands and so are ideal for robotic operations.
The actual heat source consists of a short wave infrared emitter with a QRC coating which enables the infrared light to pass into a quartz tube, which functions as the light guide. According to the requirements of the process, this light guide is then pointed precisely to the point where the heat is needed. This precise heating means that there is no heat damage in the immediate environment and no heat impact on sensitive electronics or other coated surfaces.
Contour-matched infrared emitters can join or deburr
Common to all contour-matched emitters is their specific design in terms of shape, size and spectrum, in line with the desired process. In this way, edges, corners, rims and very small surfaces are heated in a targeted fashion, which offers real benefits for plastics processing.
Housing parts, covers, suction pipes or caps are often manufactured in plastic by injection moulding. During this manufacture, it is not always possible to prevent sharp edged burrs, especially in the mold parting line. Especially with complex geometry parts, the removal of such burrs before subsequent processing or coating can be a real challenge.
Infrared emitters of quartz glass can be fashioned to match the edge or burr so that they exactly melt away the burr without damaging the actual workpiece itself. As such they are far superior to many conventional techniques, such as special blades or using gas flames, which often do not produce repeatable results and take time.
Using contact-free infrared heating, plastic parts can be joined together without the need for adhesives or other means. In a very short time, the infrared radiation melts a thin surface layer of the individual plastic component. By simple compression this can then be joined with, say, containers for screen wash or brake fluid. In contrast to contact welding using hot plates, no plastic material adheres to the heat source and the heating stage is carried out at one second intervals and the result is repeatable every time.
Infrared heat saves energy
Infrared emitters offer the great advantage of making heat available in a targeted manner. Heat only where it is needed and only for as long as the process requires it. Infrared emitters are matched exactly with the production step, they heat large surfaces just as well as thin edges. Flexible designs means that they can also be matched to complex geometry workpieces. As infrared emitters can be switched on and off in seconds, they are very energy-efficient and in the final analysis production costs are reduced.
Heraeus Noblelight offers the complete palette of infrared from near infrared (NIR) to medium wave carbon technology (CIR). Heraeus Noblelight also carries out tests with specific materials and advises on the choice of the emitter best suited to a specific process.