Automation that has proven itself

The frames loaded with the components are transported on a hanging rail into the cleaning system. (Copyright: YASKAWA Europe GmbH)

After cleaning, the racks automatically move to the correct removal position. (Copyright: YASKAWA Europe GmbH)

Eight Motoman GP12 robots pick up the components and place them into KLTs. (Copyright: YASKAWA Europe GmbH)

A camera inspection during sampling ensures that the components are correctly placed in the KLTs afterward. (Copyright: YASKAWA Europe GmbH)

The filled KLTs move along an FMS conveyor line from MiniTec to the storage rack, while empty boxes are returned to the robots for reuse. (Copyright: YASKAWA Europe GmbH)

To better respond to fluctuating order volumes, the specialist HMT has automated a cleaning system for industrial parts from MiniTec more extensively – with clear success.

"Not just clean, but pure" was once the promise of a well-known detergent commercial. A similar claim is also made by HMT – Häseler Metalltechnik GmbH from St. Georgen – when it comes to cleaning technical components. The company, founded in 1983, specializes in stamping and forming technology as well as component cleaning for very high technical cleanliness requirements. Its customers are mainly in the automotive sector. The parts are mostly stamped components that come into contact with electrical components and circuit boards.

Joachim Hölzl, the company's Managing Director of Technology, speaks of an all-in-one solution that HMT offers: "We have stamping and cleaning completely under one roof on 12,500 square meters. Our range of services extends from stamping, forming, and deep drawing to component cleaning – including residual dirt analysis in our own laboratory. We are capable of fulfilling almost any customer request. The foundation for this is our own toolmaking, a modern machine park, and dedicated employees with in-depth knowledge. Our processes and procedures meet the highest automotive standards."

Fluctuating order volume as a challenge

HMT operates two cleaning systems. Under normal load, work is done in two shifts, enabling the throughput of around 40 million components per year. Previously, many activities in the cleaning process were performed manually by employees. But the general labor shortage became increasingly noticeable. Collaboration with staffing agencies also did not provide a satisfactory solution. The reason was the volatile weekly changes in order volume, as Joachim Hölzl explains: "This made reasonable resource planning difficult – and also reacting quickly to new conditions. One week, the demand rises, and by the time we have integrated the capacities through personnel, the week is almost over."

For the future, Hölzl wished for more reliable planning and control, and more flexible responses to capacity fluctuations. This goal was to be achieved through increased automation – focusing on the loading of transport racks with parts for the cleaning process and their subsequent removal.

Automation for more flexibility

Initially, a team of internal specialists, led by Tobias Seemann, Head of Automation at HMT, worked together. They performed an ABC analysis of the components and discussed possible solutions. Hölzl explains: "We built our own internal laboratory and started with a training robot for initial experiments. The results were very impressive. We then contacted Yaskawa, who provided us with one of their robots for the next steps. Once we were confident about the feasibility, we sat down with MiniTec as system integrator. We presented our visions to automation expert Peter Müller and discussed how the system could look based on our specifications and requirements. He then developed a concept for implementing the solution, and the project moved into execution."

The result was a highly complex system where the removal of cleaned components and their storage and retrieval are fully automated. The design with two identical removal stations ensures sufficient capacity. A total of eight Motoman GP12 robots handle the removal of parts from the carriers. The GP series robots are characterized by high speeds, accelerations, and repeat accuracy. The entire system is coupled with a fully automated storage system. The system measures 20 m x 10 m, making it quite extensive.

Current process

The components to be cleaned arrive at HMT in various packaging types (grid boxes, wooden boxes, cartons, etc.). At the intake station, they are still manually removed from the containers and fixed onto cleaning fixtures.

Then, the system retrieves the fixtures from the buffer storage. They pass through the cleaning process over a hanging conveyor in different zones along a 60-meter length. From there, they go into the drying room, then into the cooling chamber, and finally into the cleanroom. Depending on the technical specifications of the components, the cleaning fixture either remains there for removal or proceeds further into the cleanroom, where the robotic removal stations are located.

Since the components can still move during the cleaning process, there can be a discrepancy of one grip between different removal points. Therefore, a camera inspection is performed here to determine the coordinates, ensuring the components are correctly positioned in the KLT containers. This guarantees that the order of components is maintained when passing to other departments.

Thought-out control system

The loading process involves assigning a barcode to each cleaning fixture, indicating which parts it contains and to which removal station it must go. At the removal station, item-specific information is transmitted via an interface between the cleaning system and the robot cells. Joachim Hölzl explains: "This way, the robot knows exactly which component is coming, in what quantity. It also knows how many to pick up. And if a component has gone missing, it subtracts one from the target number. So, we always have the correct count of parts removed."

Automatic transfer technology from MiniTec

Each robot has a KLT container in front of it. It removes the parts from the cleaning fixture and properly places them into the box. When the specified quantity is reached, the KLT automatically moves out, and the robot is provided with a new empty box.

The filled KLT then automatically moves via a conveyor to a storage rack. The transfer system is an FMS (Flexible Manufacturing System) from MiniTec. It transports the boxes via curves or turntables. A special feature of HMT's version is that instead of conventional workpiece carriers (pallets), the KLT containers are directly driven by roller chains.

Storage and retrieval via shuttle

At the storage rack, a shuttle system developed by MiniTec handles the automatic storage and retrieval of KLT containers, moving back and forth. It also transports components for visual inspection. This area is equipped with a control station where employees can see which parts are in the storage system. They can request the parts to be inspected via a control panel. As a result, the shuttle starts the retrieval process and supplies the KLT containers for visual inspection via a conveyor system. There, the parts are examined according to customer defect catalogs. If they are OK, they are packed into customer-specific packaging.

Significantly increased flexibility

Joachim Hölzl already perceives the benefits of the system after the initial commissioning: "The main advantage is flexibility. Today, we have the decisive benefit of being able to increase capacities at short notice at any time."

He is also satisfied with the project process: "The collaboration within this trio of MiniTec, Yaskawa, and HMT worked very well and ultimately led to an excellent result. As mentioned, Yaskawa supported us by providing a robot. But MiniTec, as the system integrator, also supported us intensively. Simulations, cycle times, such topics. It was an excellent collaboration, especially with Peter Müller. His experience in project business and his technical expertise added enormous value, also for HMT. The combination of Tobias Seemann and Peter Müller was fantastic. I greatly appreciated the communication, project planning, and MiniTec's experience. Many ideas were developed during the project. Small improvements were identified and quickly implemented. Marcel Therre and Phillip von Ehr also contributed wonderfully – true team players."

Further expansion of automation as a goal

The HMT boss is generally very open to automation topics. He is already considering switching the loading of the cleaning fixtures from manual to robotic. Another area is the removal of components in the cleanroom. "We have many approaches here, not only in production. There are also numerous automation possibilities in administration, some of which we have already implemented. In the future, we want to analyze all areas to see which processes can be automated to minimize human error as much as possible." Accordingly, the automation department has grown to four people.

And due to the positive experiences, Yaskawa and MiniTec will also be involved again in the future.