Industrial 3D printing requires plastic materials that, as printed components, correspond to the performance level of injection-molded components. This is the key to finding application for special components or in the spare parts market without major qualification effort and design adjustments. The standard materials in the plastics industry primarily include PP GF10, PP GF30 or PA6 GF30 - i.e. fiber-reinforced materials.
Powder bed processes such as laser sintering offer almost unlimited geometric freedom when printing components. Which is necessary because the components originally designed for injection molding have complex geometries. Unfortunately, reinforced polymers in powder form are a contradiction in terms. You can make do with fibers mixed dry into plastic powders. However, unbound, very thin fibers or mineral microscopically thin needles are risky to handle from an occupational safety perspective and for this reason do not receive internal approval from industrial 3D printing processors. It doesn't help, the fibers have to get into the particles!
In cooperation with EVONIK, LEHVOSS has now developed a PA613 with compounded carbon fiber reinforcement. The base polymer PA613 was designed by EVONIK specifically for laser sintering. As such, it is characterized by low moisture absorption, high temperature stability and – unlike PA6 – high process stability in laser sintering. The fiber reinforcement consists of high-strength XCF fibers, which have previously been used in LUVOCOM XCF products for injection molding. When it comes to powder production, new approaches to particle technology were taken in order to preserve the fiber lengths in the individual particles as best as possible.
Printing the LUVOSINT PA613 9711 CF requires a build chamber temperature of 195 °C, which makes standard laser sintering machines suitable for processing. The material absorbs the wavelengths of CO2, diode or fiber lasers. “The fact that the first automotive OEMs have already qualified for spare parts production shows that we are on the right track. Nevertheless, in laser sintering, there still needs to be a lot of willingness to innovate in order to develop even more industrially relevant materials - including machines optimized for this - in order to bring industrial 3D printing into "series"!" says Dr. Marcus Rechberger, product manager for LUVOSINT at the LEHVOSS Group.