| abstract |
A sponge roll, such as a toner supplynroll, a transfer roll, a cleaning roll, andeveloping roll and a charged roll which arenused for a copier and a printer which utilize annelectrophotographic system. The sponge rollnhas a shaft member, and an elastic spongenlayer, at least a part of an outer circumferentialnsurface of the shaft member being formed as anrough surface having a ten-point averagenroughness (Rz) of 5-300 µm, the elastic spongenlayer being integrally molded with the shaftnmember on the outer circumference of the shaftnmember without interposing a layer of anbonding agent therebetween. Merely forming anspecific rough surface on the shaft member andnmolding the shaft member and elastic spongenlayer together enable a large adhesive strength to be obtained therebetween, so that the sponge roll can sufficiently deliver a higher operatingnspeed and a higher durability required by an electrophotographic copier, the sponge roll requiring no layer of a bonding agent between thenshaft member and elastic sponge layer, unlike a conventional sponge roll, whereby it becomes possible to prevent oozed-out bonding agentnwhich causes contamination, and render troublesome steps, such as a bonding agent application step and a bonding agent drying stepnunnecessary, i.e., simplify the sponge roll manufacturing steps. |