US Patent 7680439 Interference fit sleeved foam charge rolls and composite materials

The present invention is generally directed to composite materials or charge rolls comprising a sleeved foam charge roll where the sleeve is interference-fit over the foam core, and methods of constructing them. The foam core can be made with an outer diameter larger than that of the sleeve inner diameter. The sleeve can be interference fit over the foam core to provide a functional charge roll. In some embodiments the charge roll can be used in an image forming apparatus including, but not limited to, an electrophotography system, an electrophotographic copying machine, and a laser printer.