EFFECT OF PRINT BED'S HEAT FLOW ON CURLING AND SURFACE ROUGHNESS OF FDM-PRINTED ABS SAMPLE

The optimization of printing parameters, in particular the print bed aspect, is essential for the further improvement of print quality. This paper investigates the effect of the print bed's heat flow and surface properties (i.e. materials and surface roughness) on the curling defect and surface roughness of the ABS -based dog bone designed print. The print bed temperature is varied, and the corresponding heat flow is measured using a portable heat flow meter. The maximum z deflection (curling) of the print is characterized using Geomagic Control X metrology software by measuring the dimension deviation of the 3D scanned print compared with the CAD drawing. The surface roughness in terms of the Ra and Rz of the print are obtained by a stylus-based contact profilometer. The measured heat flow data have a positive linear correlation with the print bed temperature, which is confirmed by our theoretical calculation. The surface roughness of the print is higher when printed on the zinc plate-overlaid print bed, compared with the standard (unmodified) print bed. Furthermore, the applied heat flow has a large positive correlation with the print's roughness but no correlation with the maximum z deflection. The roughness and z-deflection behaviour are attributed to the curling at the grip section of the print, resulting in a shorter interaction time with the print bed surface compared with the gage section that remains in physical contact throughout the 3D printing.