Case Study: To print, or not to print? Carl GmbH knows the answer…

Distillery equipment manufacturer Carl GmbH is using an x400 3D printer to reduce their manufacturing costs. Carl GmbH has been manufacturing equipment for artisan stills, distilling and brewing for over 140 years. The Swabian company delivers and installs factories all over the world. When they received an order from an Irish whisky distillery, they broke new ground and used cast copper. 

The casting core for it was produced with an x400 3D printer from German RepRap. The new plant was required to hold over 10,000 liters of mash in two stills. The challenge faced by the company was to create a good connection between the still and cooling system in large dimensions. The solution was the manufacturing of a conical and bent copper elbow with a flange at both ends.  The elbow is 97 x 63 cm in size and the pipe diameter is 43 cm at the larger flange. “The normal procedure would have been to beat out the shape with a hammer and anvil, and this would have taken about six weeks,” explains Thomas Keller, responsible for the technical aspects of the project.

The costs for this- several thousand dollars’ times two, since each still required one elbow to the cooler. This is why the alternative of copper casting was considered. Keller sums up the main problem: “How do I get a mold without paying too much?”. A cost calculation showed that cutting and milling would have been just as uneconomical as beating it out by hand.

After doing some research Thomas Keller came to the conclusion that it would be worth trying to create the casting core for the sand cast using a 3D printer. He therefore went in search for a 3D printer with the best price-build envelope ratio to suit his specifications. In the end the company bought an x400 3D printer from manufacturers German RepRap. As both elbows could not be printed in their entirety, despite the large build envelope, they were broken down into 22 and 16 parts. This ensured a suitable size for printing; the printed casting core is made up of two halves. The individual parts are bonded together then sealed and at the end of the process the entire model is sanded down. The design of the 3D printed models already allowed for lips for a wax film, which is melted out as a disposable model. After the wax is melted out, the liquid copper is poured in. This produces an individually molded copper elbow through 3D printing and sand casting.

Keller printed his casting cores with PLA filament. These polyactides are melted at 210oC and applied in thin layers of approximately 0.1 mm to a 3D object. “PLA can be printed easily and produces some very reliable results,” Keller explains his choice. One part was produced after two and a half days of printing, using a speed setting of 50 mm/s and 250%, i.e. 125 mm/s.The new production process paid off.  Carl GmbH now already has its second x400 printer.

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