Focused optimization of problem areas

What this means in concrete terms has already been demonstrated in the deep drawing of heat shields, as required in automotive engineering, exhaust technology and aerospace engineering. It is important to note that to date it has rarely been possible to produce these sometimes geometrically complex sheet metal parts reliably, flawlessly and without accepting considerable reject rates. All too often, excessive wrinkling, unacceptable thinning or even cracks in the material throw the faulty component out of the value chain. In this context, industry insiders report - admittedly only off the record - reject rates of between ten and 40 percent! With their new tempering system, however, Hotset and Dornbusch are now offering a system solution that should make it possible to produce intelligent cold forming tools for the low-defect and resource-saving series production of high-quality heat shields made of aluminum and similar thin sheet metal parts.

Partial and focused

The mode of action and efficiency of the new temperature control solution are based on the fast, precise and only partial heating of the tool at the moment of forming. It is a system of three-dimensionally heated thermal segments integrated into the deep-drawing tool, which are infinitely adjusted to temperatures of up to 400° C via a finely tuned control module. "The temperature control of the tool, which is only partially focused on a few areas or points, ensures that the sheet metal structure is de-stressed and heated precisely and only where it is necessary or intended during deep drawing," explains Sven Braatz, Sales Manager and authorized signatory at hotset.

The result is formed sheet metal parts with reduced wrinkling and a low tendency to crack and thin out. The new temperature control system increases process reliability and improves the quality of the parts and their surfaces. At the same time, the number of faulty parts is reduced, which in turn conserves resources and reduces material procurement costs. As an additional plus point, Andreas Filler points out that "further savings potential arises from the fact that only one or two tool sets may be required when using partial temperature control - instead of three or more".

Flexibility simplifies retrofitting

The integration of the new temperature control solution into the forming tool is preceded by a detailed analysis of the problem areas. This analysis as well as the design and construction of the system are part of Hotset's scope of services, whereby Dornbusch's toolmaking expertise is always incorporated. Even during the testing phase, it became clear that the new temperature control system can be designed so flexibly that even older deep-drawing tools can be optimized as part of retrofitting projects. It is particularly effective with aluminum sheets with thicknesses between 0.6 and 0.8 mm.

In the field of plastics technology, Hotset has made a name for itself in recent years with various toolmaking innovations that are now standard equipment for many injection molders. With the new solution for partial temperature control of cold forming tools, the company is now putting its expertise at the service of sheet metal processing for the first time.