Abstract
This work describes the production of a spherical polybutylene terephthalate (PBT) powder and its processing with selective laser sintering (SLS). The powder was produced via melt emulsification, a continuous extrusion-based process. PBT was melt blended with polyethylene glycol (PEG), creating an emulsion of spherical PBT droplets in a PEG matrix. Powder could be extracted after dissolving the PEG matrix phase in water. The extrusion settings were adjusted to optimize the size and yield of PBT particles. After classification, 79 vol. % of particles fell within a range of 10–100 µm. Owing to its spherical shape, the powder exhibited excellent flowability and packing properties. After powder production, the width of the thermal processing (sintering) window was reduced by 7.6 °C. Processing of the powder on a laser sintering machine was only possible with difficulties. The parts exhibited mechanical properties inferior to injection-molded specimens. The main reason lied in the PBT being prone to thermal degradation and hydrolysis during the powder production process. Melt emulsification in general is a process well suited to produce a large variety of SLS powders with exceptional flowability.
Highlights
Industry increasingly adopts additive manufacturing (AM) as a way to produce prototypes and small series of end-use parts in a fast, reliable, and cost-effective manner
The melt emulsification method is exceptionally suited to make powders with spherical geometry in the size range that is required for laser sintering
Compared to conventional laser sintering powders, the powder that was fabricated in this study showed outstanding flowability and packing density properties
Summary
Industry increasingly adopts additive manufacturing (AM) as a way to produce prototypes and small series of end-use parts in a fast, reliable, and cost-effective manner. Indicate that amongst the AM technologies that use polymers as a feedstock, laser sintering offers high levels of design freedom and productivity. The limitations of the laser sintering process are the high equipment investment costs, and the limited number of usable materials. Laser sintering is a powder-based process wherein parts are created layer-by-layer. The cross-sections of parts present in this layer are molten by scanning the surface with a CO2 laser. The build platform lowers by a single layer thickness, and the process is repeated. In this way, three-dimensional objects are created
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
