Microwave dielectric characterisation of 3D-printed BaTiO3/ABS polymer composites
“Microwave dielectric characterisation…” where the Noztek Pror extruder was heavily used to produce the results.
From Oxford University, UK
The BaTiO3 microparticles (nominal particle size specified by the manufacturer as < 3 μm, Sigma-Aldrich, St.Louis) were dispersed in the ABS (MFI-22, Styrolution, Frankfurt am Main) as follows. First, the ABS pellets were dissolved in acetone, typically using about one litre of acetone per 200 g of ABS. This created a solution with sufficiently low viscosity that the BaTiO3 microparticles could be readily added and mechanically mixed in by hand. The resulting suspension was then left at room temperature in an open container and mixed periodically; the viscosity increased as the acetone evaporated off, resulting in reduced sedimentation. With the suspension in a high-viscosity and well dispersed state, the material was spread on polytetrafluroethylene trays and left to solidify via continued evaporation of acetone. The resulting sheets of polymer composite were then ground using a kitchen blender into a coarse powder. The powder was then left, typically for about a week, in a drying oven at ≈ 70 °C, to ensure effective removal of any remaining acetone.
The composite powders were extruded using a Noztek Pro filament extruder to form filament suitable for use as feedstock in fused deposition 3D printers. With appropriate choice of the nozzle diameter (in the range 1.4–1.7 mm) and careful control of the nozzle temperature (typically in the range 190–210°C), filaments with a circular cross section of average diameter of 1.75 mm and a typical standard deviation of 0.02–0.03 mm were produced
Download the full paper here: SR_6_22714_2016