Enabling powder bed fusion (PBF) processing of polyether imide (PEI) through mixed-phase solvent processing

Abstract

Polymeric material options for powder bed fusion (PBF) additive manufacturing (AM) techniques are typically limited to semicrystalline thermoplastics with large differences between their melting and recrystallization temperatures. Amorphous thermoplastics like polyetherimides (PEIs) are desired in certain applications but cannot be effectively processed by PBF due to their lack of crystallinity. Herein, we present a new solvent processing method which induces crystallinity in a particular grade of PEI, Ultem CRS5011, thus enabling its processing by these techniques. This new solvent treatment approach improves on others reported in the literature which either use carcinogenic solvents or yield solvent-soaked powders that are difficult to process in the 1–5 kg range suitable for bench-top units. In an initial scoping study, we identify acetophenone as a suitable non-hazardous solvent for this process which we then scale to the ∼kilogram scale. Finally, we demonstrate processability of this feedstock by PBF-LB/P using a bed temperature (T_bed) well above the T_g of this feedstock.