Reducing Scrap, Improving Blasting, and Optimizing Sand Return

Eisengiesserei Baumgarte in Bielefeld Germany is an experienced gray and ductile iron foundry with origins dating back to 1932. After nearly a century of operation, Baumgarte is well-equipped and experienced at navigating the ever-changing iron castings market: Their product line includes pump bodies, washing machine components, piano parts, bus and railway components, textile- and wood-processing machinery parts, and gears. Because of the variety and high-quality requirements for these cast products, Baumgarte is continuously pushing the boundaries of manufacturing and technology, specifically in terms of innovations and capabilities to optimize its production processes.

Today, Eisengiesserei Baumgarte has expanded to produce 28,000 metric tons/year of high-quality castings. Familiar with the typical shakeout system for cooling castings, the Baumgarte team was hesitant to consider a process that would use a vibrating drum to cool castings and condition sand. However, the VIBRA-DRUM® sand casting conditioner presented the possibility of eliminating the need for two separate systems, removing and returning sand while cooling the castings within the drum.

Eckhard Winter, managing director at Eisengiesserei Baumgarte, explained some reservations the foundry managers had about the new equipment: “We were worried that the castings would get stuck or catch in the drum, and that by using a very short shake-out/sand separator after the drum, an aggressive action would be needed to separate the residual sand sticking to the castings, which would cause damage.”

General Kinematics working alongside Cyrus, a German manufacturer of material handling equipment, was certain that the VIBRA-DRUM® could improve Baumgarte’s casting process and reduce scrap rates, in comparison to the classic shakeout and casting cooling system. In order to ease the concerns of the Eisengiesserei Baumgarte team toward the unknown system, the group visited two foundries in Italy currently using the VIBRA-DRUM®. The points of concern quickly dissipated upon viewing the operations of the two foundries. General Kinematics’ Italian customers explained that since installing the VIBRA-DRUM® they had seen a reduction in scrap rate, improvement in shot blast operations and optimization of their sand return system.

“That put an end to our doubts,” Winter recalled of his thoughts on that visit. “It left a very positive impression. Without those visits, we would never have taken this step.”

After gaining confidence from their site visits, the Eisengiesserei Baumgarte team made the decision to invest in the VIBRA-DRUM® sand casting conditioner. Within weeks of the installation, Baumgarte manageers had noticed the benefits that were described to them during their visits to the sites in Italy.

The installation of the VIBRA-DRUM® sand casting conditioner has impacted the Baumgarte process in a variety of ways. The drum effectively produces homogenized return sand and cleaner castings now leave the unit. The cooling of the castings is expedited by the incorporation of a moisture addition system, which the Baumgarte team identified as a great benefit. The previously separated shake-out and cooling process often would require certain castings to be held off-line, to allow adequate cooling before workers were able to handle them. That process slowed production.  The impact in processing time with the VIBRA-DRUM®, according to Winter is: “this new system improves not just the quality of our products, but also our productivity.”

The gentle tumbling action of sand and castings provides a cushioning effect, making it an ideal approach for unmolding even the most delicate of castings. In fact, Eisengiesserei Baumgarte was able to eliminate risers from types of casting patterns that initially had been added to protect the castings from abrasion and impact during shakeout. Currently, the foundry is running tests to expand its product line, and they expect they will be able to include even more delicate castings.

With over 100 VIBRA-DRUM® sand casting conditioners installed around the world, this first drum installed in Germany at Eisengiesserei Baumgarte is a milestone for advancing foundry and metalcasting processes.