Foundry Corporate News Topic Enviroment, Energy & Safety Topic Plant Technology, Equipment Topic Testing, measuring & Quality Control

A new reclamation plant for "Jobbox molding materials" for additive manufacturing in a 3D molding material printer with an electrically heated rotary drum furnace

The additive manufacturing of sand cores and sand molds using 3D printing (often with furan binder) is becoming increasingly important in foundries.

Reading time: min

Fine new quartz sand is frequently used as a molding material, but other, significantly more expensive molding materials, such as synthetically produced cerabeads, are also used.

The end product—the cast parts to be manufactured—places various demands on the quality of the molding material. At the end of the printing process, the loose, free-flowing "Jobbox molding material" is transported out of the job box with suction devices. In many cases, it is sufficient to sieve the Jobbox molding material to remove coarse components, so it can then be reused in a high percentage for the manufacturing process of the next mold/core parts. A small percentage of the activator usually remains on the grain and is re-wetted with additional activator in the mixer before the 3D printer. Some cast parts with little or no tolerance for gas defects do not allow the use of previously used "Jobbox molding material."

For such Jobbox molding materials, a reclamation plant was designed, developed, and commissioned for and with the highly innovative prototype and small series light metal foundry, Becker CAD, CAM, CAST (Becker CCC) in Steffenberg-Quotshausen. This plant largely removes the activator from the previously used Jobbox molding materials, making it reusable in nearly the same quality as new molding material. Ralf Dehnert, head of small series production at Becker CCC, set the task, precisely defined the necessary process parameters, and significantly influenced the process technology. Martin Dahlmann, responsible for special molding materials at Hüttenes Albertus (HA), contributed his knowledge of the synthetic molding material cerabeads used at Becker CCC, and G U T Giesserei Umwelt Technik GmbH handled the plant technology and concept.

It quickly became clear that only a thermal process was an option, so the first step was to find a suitable furnace that was heated electrically rather than using fossil fuels. The choice fell on a hinged-tube rotary drum furnace made in Germany, which fulfils all the criteria. Regeneration tests carried out with a test furnace at the manufacturer's premises were successful right from the start; the job box moulding material regenerated on a trial basis could be successfully reused in the Becker CCC 3D printer.

The plant has the following essential components:

  • Feeding area for 4 approx. 1m³ transport containers
  • Furnace charging device
  • hinged tube rotary drum furnace
  • Fluidised bed cooling separator
  • Angular bucket elevator
  • Vibrating sieve station
  • Discharge area to approx. 1m³ transport container
  • The throughput capacity is 75 kg of moulding material per hour.

Michael Becker, the managing partner of Becker CCC, believed in the success of the overall concept and provided the funds for the prototype. And rightly so, because the system runs successfully and regenerates - around the clock on working days in semi-automatic mode - job box moulding material that can be easily reused in the 3D printer.

Ralf Dehnert, Becker CAD CAM CAST GmbH, 

Martin Dahlmann, Huettenes Albertus (HA), Düsseldorf, 

Jens Müller-Späth, G U T Giesserei Umwelt Technik GmbH, Freudenberg, 

Company Info

Giesserei Umwelt Technik GmbH (GUT)

Obere Hommeswiese 2-4
57258 Freudenberg

Telephone: +49 (0)2734 2809 0