Repeatability of Multi-jet Fusion Prints of Polyamide 12

The paper analyses the variable quality of parts printed with multi-jet fusion (MJF) technology among different commercial suppliers of 3D printing. The MJF additive manufacturing method is based on sintering polymer powder with infrared radiation and thanks to its productivity and good mechanical properties is on the rise in many industries. The aim of the paper is to compare the properties of polyamide 12 MJF printed parts declared by the manufacturer and those reported in literature with the properties of printed samples from the suppliers who offer multi-jet fusion manufacturing commercially. The paper focuses on the differences in mechanical strength and dimensional accuracy. Most importantly, it shows statistically significant differences among suppliers in both of these investigated parameters. Also the average tensile strength of the samples does not reach the value declared by the manufacturer. When compared to results reported in literature the repeatability of ultimate strength is lower. And the deviation of dimensions is significant and overwhelmingly on the plus side which is also slightly in contradiction with the results in literature.