3D Printing Mold Opens Up New Applications in Automotive Manufacturing

The 3D printed molds, which have faded in the field of aerospace applications, have found new uses in automotive manufacturing.

As early as 2015 at JECWorld, a large 3D-printed composite laminate mold attracted many eyeballs. It was developed by the Plateau Composite Technology Center, which is part of the University of Southern Brittany in France, with the goal of creating parts as quickly as possible. This pair of 3D printing molds combines additive manufacturing (AM for short), automatic fiber placement (AFP) and other processing technologies. This concept reduces the overall time for component design, tooling manufacturing, robot programming, and component layup.

The university professor Yves Grohns said that his team has collaborated with PSA Peugeot Citroen on the roof components of the 208 demonstration model. Partners involved in the cooperation include:

➤ Coriolis Composites Technologies, a supplier of robotic systems;

SMM, the company uses additive technology to make tooling.

The idea stems from stl, igs, or other CAD-virtual parts in source file formats that are compatible with 3D printers and automated tape lay-up programming. Using the CAD files of the parts, the design and shape of the molds were developed. Then, SMM started to print it. On SMM's large Fortus 900FDM machine, the mold is printed. At the same time, Coriolis has developed suitable component layups and AFP machine path planning.

The Fortus 900FDM additive manufacturing facility provided by Stratasys has approximately 1m3 of effective construction space, and the total build time is approximately 100h. Stratasys supplied the polycarbonate powder for the print, and although it was fiber-free, it still achieved sufficient rigidity and thermal stability. Grohens said: Although the demonstration tooling uses polycarbonate, but for practical production, can be made of polyetherimide (PEI) Ultem material to meet the higher curing temperature and higher pressure of 180 °C Application requirements. For this demonstration mold, the actual curing temperature is limited to 140 °C. The weight of the mold after printing is 14 kg and it is not necessary to perform any kind of processing on it. The mold was then immediately placed under the Coriolis robot's head and part layup was performed using a 6.5mm wide carbon fiber/epoxy prepreg tape.

Grohens said that this “layout process that can be completed in one day” has achieved success for the first time. This is because mold construction, component design, and robot processing are simultaneously developed in the same digital space. If a machined metal mold is used, trials of the parts are required to ensure the correct lay-up. This process takes at least two months. Although the untreated mold did not cause troubles for the lamination and curing of the parts, the mold surface was somewhat rough. Therefore, an epoxy coating was applied to the surface of the later printed mold to reduce the roughness and provide a better surface effect.