| 摘要 |
<p>A toner supply roll (26, 62) including a cylindrical soft polyurethane sponge structure (34, 66) formed on an outer circumferential surface of a metal shaft (32, 64) by foam molding of a polyurethane material in a mold cavity (56, 86) of a mold (50). The sponge structure having hardness of 350g or lower includes a skin layer (36, 69) having a network of cells (38, 68) and openings (40, 70) open in its outer circumferential surface and communicating with the respective cells located adjacent to the skin layer, such that the openings are substantially aligned with central portions of the cells in axial and circumferential directions of the sponge structure. Each opening has a size of 100-800 mu m, and a total area of the openings is at least 20% of the total surface area of the skin layer. The sponge structure has a plurality of protrusions (35, 74) formed on the outer circumferential surface of the skin layer so as to extend linearly or helically in the axial direction of the sponge structure. The protrusions have a height of 20-3000 mu m and are arranged in a circumferential direction of the sponge structure with a pitch of 300-3000 mu m, so that the skin layer is provided with recesses (37, 72) each interposed between the adjacent protrusions. Methods of producing the roll are also disclosed. <IMAGE></p> |
