There is no absolute answer to the question of whether you should use 3D printing or injection molding for prototyping. It depends on the application. For some applications, though, 3D printing offers advantages over using injection molding for prototypes. German switch manufacturer, Berker, for example, significantly reduced its production costs and time for testing electrical component prototypes by using Stratasys 3D printed injection molds.

A newly designed electrical component required parts produced using injection molding. Once assembled, the parts had to pass an electrostatic discharge (ESD) test conducted by an independent testing agency, which meant that the switch prototype had to use the same materials as the final part. Instead of using metal injection molds to test the designs, the engineering team decided to try 3D printed injection molds produced on a Stratasys Connex multi-material 3D Printer. One of the biggest challenges was that the newly designed parts needed to fit precisely in order to snap fit together with an existing metal mold-produced part.

The engineers produced a series of 3D printed injection molds using Stratasys PolyJet 3D printing technology with Digital ABS material. Each 3D printed mold, with a different geometry, was used to inject a different final part material: ASA, PC and TPE.

“This new flexibility enables us to try out two or three different solutions at the same time to get the best result,” said Andreas Krause, Head of Technical Department & Manufacturing, Berker. “The confirmed quality of our products produced using these functional prototypes has accelerated our R&D processes.”

The resulting time and cost savings were an average 83% reduction in cost per mold and 85% reduction in production time.

“3D printed injection molds helped us save time and reduce costs while making working prototype assemblies in the final material,” added Krause. “This technology is now used all over our company to make sample parts in ‘real’ materials.”

“3D printing injection molds are often an optimal solution for product prototyping and low volume manufacturing,” said Nadav Sela, Director, Manufacturing Tools, Stratasys. “For a very low production cost and quick turnaround time, they enable the manufacturer to produce parts with complex geometries in final materials before investing in mass production. And after testing the injected prototype part, if designs need to be adjusted, a new mold can be produced in just a few hours, again saving significant time and expenditures.”