METHOD FOR PRODUCING SULFONE POLYMER MICRO-PARTICLES FOR SLS 3D PRINTING

-1- METHOD FOR PRODUCING SULFONE POLYMER MICRO-PARTICLES FOR SLS 3D PRINTING [0001] The present disclosure relates generally to materials for three- dimensional printing and, more particularly, to a method for producing sulfone polymer micro-particles for selective laser sintering (SLS) three-dimensional (3D) printing. BACKGROUND [0002] Selective laser sintering (SLS) is a powder bed-based additive manufacturing (AM) technique to produce complex three-dimensional parts. When a laser beam scans the powder, the powder melts due to the rising temperature and layer-by-layer the final part approaches full density and should result in properties of the bulk material (i.e., polymer). In theory, every thermoplastic polymer that can be transformed into a powder form can be processed via this technique. However, the reality is every new material behaves differently during melting, coalescence, and consolidation, and requires optimization of the SLS processing parameters. The bed temperature and laser energy input are chosen based on the "processing" window of the polymer's thermal profile as well as its energy absorption. Laser parameters also need to be optimized based on the powder's particle size and shape. [0003] The availability of powder materials for SLS is limited, where about 95% of the materials market consists of polyamide-12 which is a crystalline nylon grade polymer. High glass transition flexible amorphous materials such polysulfone (PSU) are not available as printable powders. Unlike semi- crystalline polymer powders, amorphous polymer powder must be heated above the glass transition temperature, at which the polymer is in a much more viscous state than semi-crystalline polymers at similar temperatures. Semi- crystalline polymers are highly ordered molecules with sharp melting points (Tm). Unlike amorphous polymers, they do not gradually soften as the temperature increases, but instead remain hard until a given amount of heat is absorbed and then rapidly transform into a viscous liquid. When a semi- crystalline material is above the Tm, it has very low viscosity and will flow and -1- PROCÉDÉ POUR PRODUIRE DES MICROPARTICULES DE POLYMÈRES SULFONÉS POUR UNE IMPRESSION TRIDIMENSIONNELLE DE TYPE FRITTAGE SÉLECTIF PAR LASER (FSL) [0001] : Il est décrit généralement des matériaux pour une impression tridimensionnelle et, plus précisément, un procédé pour produire des microparticules de polymères sulfonés pour une impression tridimensionnelle de type FSL. RÉ