Selective laser sintering (SLS) of 3D printlets using a 3D printer comprised of IR/red-diode laser

The aim of this study was to employ and understand the feasibility of an infrared (IR)/red-diode laser with a wavelength of 808 nm for the selective laser sintering (SLS)-mediated sintering of 3D printlets, altering the dye composition and temperature variations. Kollicoat® IR (KIR) and an infrared (IR) laser-absorbing dye were physically mixed at various concentrations and subjected to SLS-mediated sintering to achieve 3D printlets by varying printing temperature (feed and print beds) at a fixed laser power ratio. Initially, the desired concentration of dye (1.25% w/w) was selected based on its sintering performance, and the same concentration was used to sinter the physical mixtures (PMs) at different feed bed temperatures (between 100 °C and 130 °C) and print bed temperature (120 °C to 150 °C), keeping the laser power ratio constant (1.0). It was found that good sintering performance was associated with a feed bed temperature of 130 °C and a print bed temperature of 150 °C. Printlets obtained from the aforementioned conditions showed highest dimensional accuracy (9.31 ± 0.30 mm diameter and 3.56 ± 0.04 mm thickness) in respect to feeded CAD dimensions (10 mm diameter and 3.60 mm thickness) with an average weight of 77.45 ± 4.56 mg. In addition, no physical/thermal or chemical degradation of the sintered 3D printlets was observed during the thermal and functional group analysis, respectively. Depending on the conditions given, we can conclude that an IR/red diode laser with a wavelength of 808 nm and a laser power ratio of 1.0 is feasible for sintering 3D printlets.