Every second counts

In Weinsheim, a tranquil village in the Eifel region, production is running at full speed. PRÜM-Türenwerk GmbH manufactures 4,500 interior doors and 4,000 frames here every day. Round 800 employees ensure that over one million doors leave the factory every year. PRÜM has streamlined its process chain to produce these doors even more efficiently. The goal: to save costs and increase throughput. No stone was left unturned; the specialist also redesigned the loading and unloading of the CNC processing system. Michael Gierten, project manager at PRÜM, puts it in a nutshell: "We wanted to increase the number of pieces per shift and lower energy requirements at the same time."

The history of PRÜM begins in 1970, when Streif Fertighaus AG founded a supplier-only company in Weinsheim under the name Bauelemente PRÜM with seven employees who exclusively manufactured door frames. The first doors were added in 1974. The breakthrough came in the 1990s: PRÜM introduced white lacquer surfaces, which have been the most sought-after surface on the market ever since. The portfolio includes room doors in all variants - from rotating and sliding doors to all-glass models and functional doors. Today, the company is part of the Swiss Arbonia Group.

The automated handling of door leaves, the moving part of a door, places high requirements on the technology. At PRÜM, an industrial robot moves the smooth elements from the pallet to the roller conveyor that feeds them into the processing machine. It transports empty load carriers to another roller conveyor. At the end of the line, a second robot picks up the finished door panels and stacks them.

The dimensions vary greatly: from a compact 1,000 × 300 × 39 millimetres to a massive 2,500 × 1,500 × 39 millimetres. The weight reaches a maximum of 150 kilograms. Until now, PRÜM has relied on FXP type suction pads. Two of these worked on each robot. However, the limits of this solution became noticeable: 140 gripping cycles per hour, 1,000 per shift, 13 seconds per lifting process. The compressed air consumption was 2,400 cubic meters per day. "We wanted to produce more parts in the same amount of time - and consume less energy," says Michael Gierten, "because for us, efficiency means gaining speed without wasting resources."

With the FA-X/FA-M area gripping system, the Black Forest vacuum specialist Schmalz offered a solution that was precisely tailored to PRÜM's requirements. The intelligent vacuum technology impresses with a well thought-out concept: thanks to the patented energy-saving function and individually switchable ejector nozzle strands, the gripper is particularly energy-efficient, as the system adapts its power to workpieces of varying dimensions. The sealing foam can be replaced in minutes thanks to the quick-change adhesive film, which lowers downtimes to a minimum and relieves skilled workers of time-consuming routine work.

The compact design and low weight of the FA-X/FA-M series enable space-saving mounting directly on the robot. A central media interface simplifies installation: power and compressed air are supplied together, even if several ejectors are integrated. A large LED display directly on the gripper provides important system information at a glance.

The results after the retrofit clearly exceed expectations. "The system is now running noticeably more smoothly," says a delighted Michael Gierten. "We can now manage 170 gripping cycles per hour instead of 140 - that's 200 more door leaves per shift. The shorter cycle time of just ten seconds has a positive effect on our entire process chain." He was particularly impressed by the energy balance: compressed air consumption fell from 2,400 to 1,600 cubic meters per day, and thus by a third. Extrapolated over the year, that's round 300,000 cubic meters less. Michael Gierten: "I also like the reliability and simplicity of the new solution."

The decision to use Schmalz was an easy one for PRÜM. "We have been using vacuum solutions from the Black Forest in our operations for many years," explains the process manager. "Schmalz is our first port of call as a supplier of vacuum technology, because the systems are of a very high technical standard, work extremely well and the consultation is excellent." The investment was a complete success for PRÜM. "Our contact at Schmalz knows our products and the challenges of the material very well and was able to present us with the optimum solution."