| 摘要 |
PROBLEM TO BE SOLVED: To suppress the hardening of polyurethane foam layers of toner feed rollers as posed by long-term use by preventing intrusions of toners into the layers. SOLUTION: This toner feed roller 26 comprises a longitudinal core bar 32 as a roller shaft, and a soft polyurethane foam layer 34 laid integrally around the core bar 32 so that its surficial cells open to the exterior individually. The polyurethane foam layer 34 has an integral two-layer structure consisting of an inner foam layer 36 and an outer foam layer 38. An inner skin layer 36a formed on the external surface of the inner foam layer 36 and an outer skin layer 38a formed on the internal surface of the outer foam layer 38 are integrated together as a composite skin layer 40 interposed integrally between the inner and outer foam layers 36 and 38. |
