Additive manufacturing of customized refractory mold cores for industrial ceramics

Průmyslová keramika, a leading Central European supplier of ceramic bodies and specialized heat-resistant ceramic components, made a significant shift in its manufacturing approach in 2016. Moving away from traditional methods, the Czech company adopted Ultimaker 3D printing technology to create mold inserts (cores). This transition resulted in mold core production being five times faster, at just 10% of the original cost, all while ensuring precise repeatability. Established in 1991, Průmyslová keramika—translated as «industrial ceramics«—has grown steadily, now generating an annual revenue of 220 million Czech crowns (approximately $9.8 million). With a workforce of 75 employees, the company produces over 9,500 tons of ceramic bodies and nearly 1,600 tons of molded components each year.

The company’s success lies in its agile response to customer needs. Each order of a ceramic piece is unique and requires a unique mold design. And this demand for constant customization led the manufacturing team to consider additive manufacturing technology.

Precision and customized industrial production

Molds are normally made from molten steel which forms the external shape. The basic inserts then define important internal and functional details such as grooves, holes and curves. These fittings often have complex shapes that must be designed and manufactured to precise customer specifications. In the past, such internal shapes were made using wooden or metal inserts. But these required manual woodworking or CNC machining, time-consuming and expensive processes. For example, a wooden insert could cost up to 20,000 Czech crowns ($895) and take more than 30 hours to carve.

During 2013, the management team experimented with a 3D printing project in an attempt to speed up mold production, but encountered problems with the first 3D printer.

“We had difficulties with the installation of the printer,” says Jakub Cvilinek, general director of Průmyslová keramika.

«Only about 30% of the prints were successful, the rest were wasted. Even after this experience I believed in 3D printing. It was a school for us. The technology was still good for us: we simply chose the wrong printer.»

Reinventing your mold-making workflow with Ultimaker 3D printers

In 2016 Průmyslova keramika chose what turned out to be the right 3D printer: or Ultimaker 3 Extended. In the end, the company found a reliable and professional 3D printing solution.

Two years later Jakub Cvilinek added a new one Ultimaker S5 to their toolkit, offering the same print quality but with a larger build volume behind a lighter user interface.

When the team leveraged 3D printing to make mold cores and inserts, the benefits of the technology emerged: accurate, fast, repeatable manufacturing and nearly complete creativity in part design. Furthermore, the solution was significantly cheaper than previous processes.

For 3D printing cores, Průmyslová keramika only uses PLA material due to its ease of use and low glass transition temperature. This is because many of the base parts and inserts remain embedded in the ceramic material until firing. At more than 900 °C PLA can easily be completely removed from the mold.

The company has two operators who supervise the 3D printing of production parts, designed by the engineering department using Autodesk Inventor and AutoCAD.

3D printing makes production easier and faster

“Ultimaker 3 Extended and S5 brought us substantial savings and production acceleration, as well as the ability to produce previously impossible shapes,” recalls Jakub Cvilinek.

For Průmyslová keramika, 3D printing proved to be an important advantage for the production process.

The required parts can now be produced up to five times faster and ten times more economically than with traditional processes. For example, the material used to 3D print the mold core for an air-gas mixer in an industrial burner costs only 300 Czech crowns ($13.43).

This means that it only took a few months for the ceramics specialist to achieve a return on investment on the initial purchase cost of the Ultimaker 3D printers.

By relying less on a CNC mill, the company also saved on labor costs.

It now benefits from on-site manufacturing, rapid prototyping, high uptime and (when required) repeatable manufacturing.

Bottom line: 3D printing offers a new level of design freedom

For Průmyslová keramika, the addition of the Ultimaker 3 and Ultimaker S5 has transformed the custom workflow. They now have confidence in their ability to produce components that meet or exceed customer needs. Jakub Cvilinek adds:

Some cores with complex shapes were not manufacturable or would have been too expensive using traditional methods. Thanks to 3D printing we can prepare them ourselves.