Evaluation of the influences of process parameters while selective laser sintering PMMA powders

Abstract

Polymethylmethacrylate (PMMA) is a synthetic resin, widely used for bio-medical applications and is usually mixed with some other ingredients to form a soft substrate, which gradually hardens. Medical implants and other products of different shapes are generated either by moulding while it is still soft or by machining further to hardening. While these methods limit the freedom to achieve the much needed geometrical complexities, porosity also gets adversely affected. Rapid prototyping or additive manufacturing techniques allow for complex shapes to be easily produced together with a degree of control over the porosity. Though fused deposition modelling was attempted earlier with PMMA, more promising approaches such as selective laser sintering attained very little attention in this regard. In particular, the mechanism of material consolidation and the effects of significant process parameters on critical responses need sufficient attention, and this paper attempts this by experimental means.

Post-process composition and biological responses of laser sintered PMMA and β-TCP composites

“…SLS was applied to PMMA powders earlier 38 but the process parameter combinations needed further adjustments based on the thermodynamic responses of the current powders. Differential scanning calorimetry (DSC) is performed using the Simultaneous Thermal Analyzer-STA 449 F5 Jupiter DSC system (NETZSCH Australia Pty Ltd., Kings Park, Australia).…”

“…The actual mechanisms and mechanics of interparticle coalescence and consolidation of layers were discussed in greater detail in an earlier publication. 38 While the current focus is on the after effects of laser sintering, some attention is paid first to the porosity levels and their variation with process conditions considering the significance of achieving controlled porosities in the target applications. SEM photomicrographs of single layer specimens of different compositions printed as per the conditions are set in Table III and presented in Fig.…”

Manufacturing the Gas Diffusion Layer for PEM Fuel Cell Using a Novel 3D Printing Technique and Critical Assessment of the Challenges Encountered

“…Sufficient inter-particle and inter-layer consolidation are achieved by optimising the laser energy flowing into the powder substrate [ 10 ]. The energy density ( E D , J·mm −2 ) per unit area along the scan line can be evaluated as per Equation (2) [ 11 ]: E D = P /( D × v ). …”

Fabrication of complex 3D composites by fusing automated fiber placement (AFP) and additive manufacturing (AM) technologies

“…There are seven distinct additive manufacturing technologies used for rapid prototyping and manufacturing purposes: vat polymerization, sheet lamination, material extrusion, material jetting, binder jetting, directed energy deposition and powder bed fusion. AM provides a high degree of design freedom, optimization and integration of functional features and enables the manufacturing of small batch sizes at economical unit costs [47][48][49][50][51]. AM systems are typically equipped with three linear motion axes to position the processing tool head relative to the building platform in a translational motion.…”