At Robert Plersch Edelstahltechnik in Hawangen, around 100 employees manufacture products from sheet metal on behalf of customers, from individual parts to entire assemblies. The company has recently started using a fully automated robot cell for surface and weld seam processing of stainless steel components. The system was designed and implemented by SHL from Böttingen together with its cooperation partner 3M.

"There were many reasons for automating the processing of weld seams and surfaces," says Managing Director Georg Plersch. "One was the fact that surface finishing, i.e. grinding, brushing and blasting, was always a bottleneck in our production process. And our customers have increasingly high demands in terms of replicability and quality. We also had to respond to this. In the stainless steel sector in particular, these are mostly visible parts, where customers attach great importance to high quality." In the search for a suitable partner for the project, they finally came across SHL. The company has been an official cooperation partner of 3M since May 2021. However, the cooperation between SHL and the abrasives experts at 3M has already been very good for several years, as Berthold Kammerer, sales specialist for grinding and polishing systems at 3M, emphasizes.

The result is a very flexible robot cell. Workpiece-guided or tool-guided, the robot can process workpieces from the size of a cell phone up to a size of around one cubic meter - with stationary and guided belt sanders and guided tools in disc form. "In addition to maximum flexibility, the programming times were of course also very important to us. We can't afford for the system to be down for a long time due to reprogramming," says Georg Plersch. Overall, the time factor naturally plays an important role. "Compared to manual processing, we were able to more than halve the times with the robot cell," says the Managing Director.

And, of course, the service life of the abrasives used also plays a major role, as fewer changes means additional time and therefore cost savings. "We don't sell our customers a product, but a solution for the entire process, and this includes high-performance, universally applicable abrasive belts and grinding wheels from 3M," says Thomas Magnussen, Head of Sales & Marketing at SHL. And so 3M Cubitron II abrasive belts and grinding wheels are used in the robot cell, which enable fast and cool grinding. Scotch-Brite non-woven belts are used for fine sanding.

"The abrasives naturally have a considerable influence on such an automated process, not only because of the quality of the surface achieved, but also because of the long service life," says Magnussen. "The big advantage of automated sanding is, among other things, unmanned working. And if I have to keep changing the sanding belt, I still have to provide an employee to take over this task," explains Plersch.

Unique overall solution

"Such a complete solution is unique in the highly competitive contract manufacturing market, and we have thus created a unique selling point for ourselves," emphasizes Georg Plersch. Incidentally, automated finishing is just another step towards comprehensive automation at Robert Plersch Edelstahltechnik. "Most of the processes in our company are already automated or fully automated - the last department was the grinding shop. We have tried to bring the entire production process up to the same level. Of course, further automation will follow; time and competition will bring this trend with them and it will be unstoppable."

According to Plersch, a decisive factor is also the shortage of skilled workers, which the company wants to counteract with such investments. "Nobody wants to do this kind of work anymore," he says, not least because of the health risks caused by the grinding dust. Incidentally, this is extracted in the robot cell, even though there are no workers in the cell during sanding. The robot sanding cell has been in operation since October 2020, and Georg Plersch draws a positive conclusion: "With my vision of a fully automated sanding process, we broke new ground and of course took a certain risk, as we couldn't fall back on a standard solution. But with SHL and 3M as partners, we were able to implement this complex and demanding project in the best possible way."