Hella has introduced an infrared welding process for the production of the rear combination lamp of the Lamborghini Revuelto. This news was published in the latest edition of Joining Plastics. DVN’s Paul-Henri Matha discussed this with Hella’s Head of Global Joining Process Technology Innovation, Dr. Odo Karger:
DVN: How does this new process differ to hotplate, laser, and vibration welding?
Odo Karger : Actually, the IR-welding is not much different from the hotplate welding process. It also constitutes a two-step-process but utilizes a different heater, a non-contact IR-emitter, similar to those widely known in rear-combination-lamp-business for infrared-preheating of vibration welding. Because it is a non-contact heating, issues connected to hotplate welding, like stinging, wear of tool, foamy weld bead, etc. are not present. In comparison to vibration welding, of course there is no vibration movement, thus there are much lower geometrical restrictions, and the precision can be slightly improved. Compared to the simultaneous laser welding cost of machines and fixtures are significantly lower while weld appearance is at least comparable if not better, as can be seen in the picture in our publication. We think IR-welding can be a very good replacement of laser welding, which is increasingly being used lately.
DVN: Can you show the machine and a section of the lens / housing?
O.K.: Our Infrared-welding machine is not much different from a hot plate welder, except the power supplies for the heater, of course. I don’t want to share a cross section of the welding area here, as there is something of the magic we developed in there.
DVN: Is it existing already between different plastic in automotive or other products?
O.K.: Definitely yes! IR-welding is far from new. It is widely used for interior application, e.g. welding of airbag boxes, and under the bonnet applications. For whatever reason it never made it into the welding of lighting devices yet. Actually, we found that the materials used here are very suitable for IR-welding, much more than many technical thermoplastic polymers used in other applications.
DVN: What is the material of lens and housing on this lamp?
O.K.: On the Revuelto lamp we use PC+ABS for the housing as well as for the black portion of the lens. This is because of thermal reasons connected to the rear engine vehicle. But also welding of other common rear combination lamp materials like PMMA and ABS are known to deliver very good results.
