Part removal of 3D printed parts

Abstract

An experimental study was performed to understand the correlation between printing parameters in the FDM 3D printing process, and the force required to remove a part from the build platform of a 3D printing using a patent pending, New Valence Robotics Corporation technology for automated part removal of 3D printed parts. These correlations are used to optimize printing parameters to minimize the force required for removal, without decreasing the quality of the printed object. The bed (build platform) temperature, extruder temperature, bed temperature during the removal process (removal bed temperature), and first layer height of prints on a Solidoodle 2 3D printer were varied independently. For each parameter tested, the orientation of the part being removed, an ellipse, was oriented with its major axis parallel and perpendicular to the blade edge. On average, the parallel orientation incurred larger loads on the removal blade mechanism by about 10 to 20%. The first layer height parameter had the largest effect on the required force, with a linear trend from 47.62 +/- 8.98 N at a layer height of 0.47 +/-0.02mm, to 123.92 +/- 22.93 N at a layer height of 0.18 +/- 0.01mm (parallel orientation). The extruder temperature parameter had a large effect on the removal force when raised close to the glass transition temperature of the build platform material, a PEI fill. At an extruder temperature of 210°C, the force was 120.53 +/- 13.55 N, more than 70 N greater than the removal force of a part printed with an extruder at 180°C. Varying the bed temperature, during printing and the removal process, caused an increase in the removal force from 60 to 40°C. Below 40°C, shrinkage in the printed part caused unadherence. Above this temperature, the cooling of the plastic causes an increase in the viscosity, and therefore an increase in the adhesion. These findings allow the user to balance adhesion, to prevent warping or movement of parts during the printing process, and low removal loads, to prevent excessive wear on an automated part removal mechanism.