A targeted material selection process for polymers in laser sintering

Abstract

Laser sintering (LS) of polymer materials is a process that has been developed over the last two decades and has been applied in industries ranging from aerospace to sporting goods. However, one of the current major limitations of the process is the restricted range of usable materials. Various material characteristics have been proposed as being important to optimise the laser sintering process, key aspects of which have been combined in this work to develop an understanding of the most crucial requirements for LS process design and materials selection. Using the favourable characteristics of polyamide-12 (the most often used material for laser sintering) as a benchmark, a previously un-sintered thermoplastic elastomer material was identified as being suitable for the LS process, through a combination of information from Differential Scanning Calorimetry (DSC), Hot Stage Microscopy (HSM) and knowledge of viscosity data. Subsequent laser sintering builds confirmed the viability of this new material, and tensile test results were favourable when compared with materials that are currently commercially available, thereby demonstrating the efficacy of the chosen selection process.

Nucleation and impact modification of polypropylene laser sintered parts

“…The highest relative increase of impact strength with 99 % is observed for parts sintered with an energy density of 24.8 kJ/m 2 . Interestingly, the impact strength of parts without nucleating agent seems to follow a negative trend with increasing energy density, in contrast to expectations and findings in [10,11] for example. A possible explanation for this observation could be the inaccuracy of sintered part cross-sectional dimensions at high energy density.…”

Fabrication of PCL/β‐TCP scaffolds by 3D mini‐screw extrusion printing

“…All analyses were performed in a nitrogen atmosphere (50 mL/min). The data analysis was performed using Netzsch Thermal Analyses 6.0.0 Proteus; transition temperatures and enthalpies of fusion and crystallization were obtained in accordance with ASTM D3418‐12 . Furthermore, thermogravimetric analyses (TGA) were performed using a Mettler Toledo TGA equipment.…”

Surface modification of the laser sintering standard powder polyamide 12 by plasma treatments

“…Polyamide 12 (PA12) powder is frequently selected for LS applications due to its easy (i.e., ease of sintering), large processing windows, high laser energy absorption, and good mechanical properties . Despite this potential, however, the consistency of mechanical performance of LS parts made from PA12 powder needs to be improved by the inclusion of fillers.…”