| 摘要 |
A toner supply roll including a cylindrical soft polyurethane sponge structure which is integrally formed on a metal shaft and which has a hardness of not higher than 350 g, a network of cells, and a skin layer having openings which are open in its outer circumferential surface and which communicate with respective radially outermost ones of the cells located adjacent to the skin layer, wherein the openings have a size of 100-800 mum, and a total area percent of at least 20% of the total area of the outer circumferential surface of the skin layer, and the sponge structure has a plurality of helical protrusions formed on the outer circumferential surface of the skin layer so as to extend helically about an axis of the sponge structure, the helical protrusions being arranged in a circumferential direction of the sponge structure, so as to form a plurality of helical recesses each interposed between adjacent ones of the helical protrusions, so that helical protrusions and recesses cooperate to define a toothed profile in transverse cross section in a plane perpendicular to the axis.
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