Toned electrophotographic images often exhibit toner satellites around alphanumeric characters and halftone dots. Among the electrophotographic subsystems, transfer is believed to be a frequent and even dominant source of such image artifacts. This paper reports on toner adhesion, detachment, and disruption as determined using a laboratory ultracentrifuge and an electrostatic detachment cell (ESD). The simplicity of this apparatus helps isolate factors contributing to satellite formation such as toner particle size, surface treatment, transfer gap (pre-nip or post-nip) and transfer electric field. Measurements have confirmed that surface-treatment can decrease adhesion and/or cohesion and increase the number, but not the spatial extent, of laterally displaced toners after gap-jumping. Results from both the ultracentrifuge and the ESD show that, even for highly surface-treated toner, only a small fraction of toner is removed by the normally-directed electrostatic forces encountered during transfer from photoconductor to paper. In contrast, relatively weak tangential forces cause toner to move laterally; suggesting an additional mechanism for satellite formation that need not involve gap jumping.
R. D. Fields, A. J. Rushing, D. S. Rimai, A. H. Hoskins, "Satellite Formation in Transfer Gaps" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP15), 1999, pp 503 - 507, https://doi.org/10.2352/ISSN.2169-4451.1999.15.1.art00033_2