3D Printing Process for Use in Space

The range of 3D printing technologies is growing: a research team from TH Köln (The University of Applied Sciences Cologne) is now working with the company mz Toner Technologies to develop a new 3D printing process based on electrophotography that will, among other things, enable printing in space.

Based on the principle of electrophotography, which is how most printers work, a research team led by Prof. Dr. Danka Katrakova-Krüger in the Materials Laboratory at TH Köln is developing an electrophotographic 3D printing process. The concept: the component to be manufactured is first "cut" into several ultra-thin layers using software. Instead of dye, polymer particles, i.e. plastics, are used. One to ten layers, a few micrometers thin, can be printed one on top of the other on a carrier film and preconsolidated by a roller. In order to finish the desired component, several of these previously printed layer packages are joined together in a second step with the aid of a heating press. Cooperation partner mz Toner Technologies is developing a prototype of the 3D printer.

Use in space

Plastics are particularly suitable for space travel because they weigh little and are mechanically resilient at the same time. A particular challenge is to implement the electrophotographic process in such a way that it can be used despite the absence of gravity. For space travel, on-site 3D printing would have advantages: Not all spare parts that might be needed during an expedition would have to be taken along. They could be made on site as needed. This saves space and weight. The scientists at TH Köln are in exchange with the European Space Agency (ESA) regarding the use in space.

Alternative to injection molding

Until now, common 3D printing processes have not been able to compete with the widely used injection molding process in terms of speed; this could change with the new technology. Injection molding requires expensive molds, slowing the start of production and making it worthwhile only when a certain number of pieces are produced. The electrophotographic process, on the other hand, does not require molds and still allows for high volumes.

"3D printing with electrophotography is suitable for all material groups such as plastics, metals and ceramics, saves weight, has increased speed and offers enormous design freedom such as the more generous use of colors," Prof. Dr. Katrakova-Krüger said. Other materials also open up another potential field of application: the household and electrical appliance market, which has so far used injection molding to manufacture appliances and their components.