System for purging contaminants from a vacuum assisted image conditioning roll

摘要

The purging system generates negative air pressure in porous image conditioning rollers (110) to draw liquid carrier from a developed liquid image (102) on an image bearing surface (10). The developed image is conditioned by compressing the image with the rollers to remove excess liquid carrier. The rolls are biased (130) to a potential with polarity to repel charged toner particles to compress the image and prevent the toner particles being removed. A vacuum source (120) draws liquid through the roller to a central cavity and then to a receptacle for disposal. The roller has a rigid porous support core (114) in the form of a cylindrical tube with hollow central cavity along its length. A microporous absorbent material (116) surrounds the core. Contaminants drawn into the pores of the roller are removed by providing positive air pressure to reverse the flow of liquid carrier through the roller. The liquid carrier and residual contaminants are pushed from the core and out of the absorbent material (112).