Six-axis robots automate the entire handling process

The annual production of approximately 1.4 million radar domes on two production lines is subject to the strictest quality requirements. These safety-critical components protect the sensitive electronics of radar sensors in premium vehicles. A 2K injection molding cell—complete with a host of upstream and downstream processes, highly innovative quality assurance, and sophisticated automation—demonstrates what state-of-the-art production lines are capable of today.
The fact that the production of these sensitive components—which are found in Audi and Porsche models—is taking place at Weißer + Grießhaber in Mönchweiler is anything but a coincidence. Founded in 1969, this family-owned company is now regarded as an innovative series supplier with its own mold-making division and, thanks to decades of experience, also sees itself as a development partner for demanding customers in the fields of automation, automotive, medical technology, and building services engineering.

The company employs about 340 people, operates 215 robots and 114 injection molding machines, and uses them to produce over 1.3 billion parts annually. At the helm is Martin Weißer, who is the third generation to lead the company and has big plans for the future: “Together with our customers, we want to develop groundbreaking manufacturing solutions with a high degree of functional integration and set new standards in line with our motto, ‘Excellence in Plastics.’ The new production line for the viewing domes clearly illustrates the direction we’re heading in.”

Time-Optimized Development in Simultaneous Engineering

Even before the production order was awarded, W+G’s engineers were closely involved in the development process at automotive supplier Bosch. At the same time, the first stations for automating the injection molding cell were being built by specialty equipment manufacturer EGS Automation in nearby Donaueschingen. “Due to the tight schedule, we had to start planning the automation in the middle of product development—that is, without final specifications. Nevertheless, we managed to draw up a rough plan by designing certain system components and processes very flexibly and ensuring they could be easily replaced and adapted,” said Hartmut Pfalzgraf, project manager at EGS Automation.

The use of simultaneous engineering played a decisive role in ensuring that the complex production line, featuring two interlinked injection molding processes, could be brought online on schedule. Here’s how the manufacturing process works: The first injection molding cell is responsible for producing the plastic base bodies with two contact pins, which is equipped with a punching line, a SCARA robot for separating and placing the contacts, a Yaskawa six-axis robot for loading and unloading the Arburg injection molding machine, and an inspection station. Here, the base bodies undergo 100% inspection before being placed in trays and stacked using a Sumo Ecoplex tray stacker from EGS Automation.

Fully automated injection molding cell with six robots

From here, the process proceeds manually directly to injection molding cell 2, where the operator returns the trays loaded with base bodies to the system via a second Ecoplex palletizing system. “Together with our trusted system integrator EGS Automation, we have succeeded in automating a complex manufacturing process with many upstream and downstream steps within a very confined space. With its total of six robots, one winding station, five integrated inspection stations, a wealth of sensor technology, and impressive manufacturing IT, this fully automated injection molding cell demonstrates what is possible today,” emphasizes Martin Weißer.
The extent of the functional integration here becomes clear when looking at the processes: First, the base body must be wound with a hair-thin copper wire, which is used for the subsequent heating of the sighting dome. This task is handled by a special winding system, which also welds the wire ends to the pins and performs an electrical continuity test. A SCARA robot handles the automation of this cell. The next step involves overmolding the wire-wrapped base body. This two-stage process is carried out by a fully electric Arburg 920-2K injection molding machine. This is followed by sophisticated inspection processes before the sight domes are marked with a Data Matrix code.

Reliable six-axis robots with high dynamics and precision

The system is so complex that only a few employees fully understand and master it down to the last detail. One of them is Emre Yeniay, Technical Engineer for Manufacturing Equipment at W+G: “The entire sequencing of all stations in the system is fully automated using five Yaskawa six-axis robots, including two GP25s for handling tasks, a large GP50 for automating the injection molding machine, and two GP7s that handle the downstream inspection processes. To ensure the gentlest possible handling of the radomes, all robots are equipped with vacuum grippers. The Yaskawa robots excel not only in precision but also in maximum uptime, which is crucial for our 24/7 operation.”