Injection molded parts packaged autonomously

Franz Wolf Kunststoffverarbeitung is a medium-sized family business in its third generation and has been on the market for over 50 years. Based in Kirchheim in Unterallgäu, the company employs around 40 people in production, toolmaking, quality assurance and logistics. Petra Kaiser, Managing Partner, and Moritz Kaiser, Technical Managing Director, cite their many years of expertise in injection molding production as well as in-house toolmaking as a key competence.

The machine park comprises around 40 machines with clamping forces ranging from 15 to 130 tons and is regularly modernized. Around a third of the machines are now fully electric, which has a positive impact on energy consumption. The company supplies customers from the automotive, electronics, hydraulics, sensor technology and communication sectors.

A small precision plastic part for a steering angle sensor is manufactured in large quantities on one of the production systems. The part is injection-molded eight times with sprue on an Arburg Allrounder 40-ton machine. The complete shot is removed by a linear handling system and separated from the sprue. A group of four parts is positioned opposite each other on the sprue. The individual parts were then previously deposited by the handling system onto a conveyor belt, via which they were placed unsorted in a box. The system had been designed, built and commissioned when the customer surprised Wolf with the request to have the parts delivered individually set in their own existing packaging.

The reason for this request is usually that the subsequent further processing is automated and the parts must therefore be delivered in an automated manner. In this specific case, this meant that an output of around 1,400 parts per hour had to be sorted into customer trays in 600×400 mm format in the correct position, 112 parts in each tray. The trays then have to be stacked on Euro pallets and fitted with a lid. This would have required just under two people during the entire production time - a very tedious task.

Although removal handling is a very fast and inexpensive solution for removing parts from an injection molding machine, it is not really suitable for inserting parts individually into trays. The existing linear handling system was therefore not a possible solution for packing into the trays. Furthermore, a solution also had to be found for destacking and stacking the trays for provision for the packaging process.

A customer has the solution

Faced with this task, Moritz Kaiser recalled information he had received in a newsletter from one of his company's customers. This long-standing customer, the company Dunkermotoren, which is supplied with injection molded parts, had announced that an automation company had been acquired and was now part of the group and thus part of the parent company Ametek. EGS Automation from Donaueschingen has been a subsidiary of Dunkermotoren since 2021 and is a provider of robot-based automation systems. The focus is on companies in the metal and plastics processing industry. EGS offers individual, turnkey special solutions as well as a product line of standardized automation solutions with the Sumo series.

Confronted with the task, EGS was able to offer the right solution based on a standard palletizing system. The system is based on a Sumo Ecoplex2, a tray stacker that can process stacks up to 0.8 m high in tray format 600×400 mm. These can be fed in and out via conveyor belts. In this specific case, the belts hold four stacks, which corresponds to an autonomy of around 12 hours. The individual parts are handled by a GP7 articulated arm robot from Yaskawa with a reach of just under 1 m and a payload of 7 kg. The remaining question was how to transfer the parts from the SGM: "The existing Dürrschmidt handling system was to continue to take over the removal. So a transfer had to be implemented, and we were worried that there could be problems in the interface area, both during coordination and later during operation," says Moritz Kaiser, expressing his concerns. However, interface coordination and work area monitoring are EGS's daily bread and butter. "Dürrschmidt made it very easy for us here with their cooperative approach to coordination," says Hartmut Pfalzgraf, responsible for this project at EGS.