What matters with a new car is not just the operational functionality but also the look and Instrument panels, in-car entertainment facias and other internal paneling are produced by injection molding before finishing. Naturally, these surfaces must be perfect – smooth without any unwanted burrs.
This is where infrared contoured emitters offer important advantages. They remove the burr precisely, without any damage to the workpiece itself. “In this way, a costly process can be automated, with reproducible results,” says Heraeus Applications Specialist, Rudolf Lembke. “We know of customers who have already carried out more than half a million de-burring cycles with the same infrared emitter set.”
At Messe K in Duesseldorf in October, Heraeus Noblelight will be showing infrared emitters, which are precisely matched to the product and process in terms of shape, voltage and output.
Faster de-burring, fewer rejects.
Plastic handles, covers and panels are often manufactured by injection molding. In this process it is not always possible to prevent the occurrence of sharp-edged burrs, for example at the tool separation plane. Especially with components of complicated shape, the removal of burrs before further processing or coating can present a formidable challenge.
Manual de-burring with gas flames or special tools does not provide uniformly repeatable results. The intermediate stage of manual de-burring costs time and in-line finishing is not possible. Infrared emitter of quartz glass can be shaped to the flow of edges or burrs and melt away the burr exactly without damaging the actual workpiece. Infrared radiation deburrs within approximately 4-12 seconds, dependent on the material or the strength of the burr. Consequently, deburring is much faster than with a Corona flame, which follows the contour of the burr little by little. With a contoured infrared emitter the complete burr can be completely removed in a single step. Infrared radiation heats plastic components without contact, targeted at the surface in seconds. Shaped emitters direct infrared radiation precisely where it is required. This is made possible through reflectors, which are applied as a coating directly on the contoured emitters. The radiation exit slit is such that the energy is directed precisely onto a burr. As a result, in-line finishing is possible and the reject rate in the production of formed components can be significantly reduced.
An automated process which saves energy
Infrared systems with contoured emitters can be easily integrated with robots and mechanical handling systems. The emitters are switched on only when the robot picks a plastic component from the injection molder and places it in front of the emitter. When the burr has been melted away, the emitter is switched off and the robot can transport the component to the next processing stage. Because infrared emitters are switched on and off in seconds, energy consumption is extremely efficient, time is saved and, last but not least, production costs are reduced.
Testing and customizing for optimum results.
Modern design demands high quality and this means that the variety of materials is ever increasing. For instrument panels, in-car entertainment facias and decorative features a mixture of polycarbonates and ABS is often used. Such components are injection molded and then finished. However, not all plastics can be deburred by heat. Polycarbonate is often transparent and creates a smooth surface but any burrs are difficult to melt away. The mixing ratio of polycarbonate and ABS in plastic components however can often make possible thermal deburring. These can be investigated using our wealth of experience supported by individual trials on site or in the Heraeus Noblelight Applications Centre.
Keywords:Infrared heat, contoured emitters, plastics processing, deburring, plastics welding, Messe K, K show