Schäfer, Jan

High-speed thermal microscopy of plasma microprinting at atmospheric pressure

The HelixJet (https://www.inptdat.de/helixjet) was applied to simultaneous melting and plasma treatment of polyamide (PA 12) microparticles (diameter 60 µm) used conventionally for 3D printing by laser sintering. This proof-of-principle experiment demonstrated that gaussian thickness profiles of PA 12 can be printed using the HelixJet with a rapid rate of 200 mg/s (peak growth 2 mm/s) and with advantageous material properties. The key element of this novel process is the self-regulated balance between material melting and plasma quenching.

Correlation of helicality and rotation frequency of filaments in the ntAPPJ

The self-organized behaviour (locked mode) of filaments in the non-thermal atmospheric pressure plasma jet (ntAPPJ) couples a spatial patterning of the discharge (helical symmetry) and a regular motion (steady rotation). The dataset represents the mean rotation frequency of filaments in the capillary with a diameter of 4 mm and the corresponding geometric characteristics: helicality and/or filament inclination angles were measured along with the gas temperature under varying discharge conditions (electric power and argon flow rate).