TRIBOCHARGING AND CHARGE MEASUREMENT INSTRUMENT
Original Publication Date: 1997-Oct-31
Included in the Prior Art Database: 2004-Apr-08
Xerox Disclosure Journal
Disclosed is a method and apparatus for measuring the tribocharge build up on toner image receiving materials, such as paper, film, plastic, labels, and the like. The buildup of static electricity on machine components and receiver sheet paper moving through copiers is a significant cause of paper handling problems. Conventional methods of throughput materials characterization, such as, surface resistivity and charge acceptance are inadequate to predict severity and location of static build up. A method which reproducibly generates and measures static charge is therefore desirable. The method comprises mounting a sheet on a driven drum, and measuring the voltage build up on the surface of the sheet as a sample material is brought into forceful contact with the sheet. The device comprises: a) a grounded rotating drum constructed of, for example, aluminum or other conductive material, and with the sample to be tested being wrapped around the drum and held in contact by, for example, vacuum hold down or conductive tape; b) a means of achieving and controlling drum rotation and speed; c) an external sample holder to position a test material against a paper sample on the drum; d) a means of controlling the normal force exerted by the test material against the paper on the drum, such as a spring loaded clamp; e) a non-contact voltage probe positioned so as to measure the charge build up on the rotating paper; and f) a means of recording the voltage measured. The device and method are useful for laboratory evaluation and manufacturing development testing of materials used for the construction of, for example, elements in a paper path, such as, friction retard feeders, vertical transport trains, duplex trays, collators, and bindexers. Results indicate that different paper chemistries have different tribocharging behavior that is not readily predicted by conventional methodologies, for example, surface resistivity measurements.