| 摘要 |
PURPOSE:To improve durability with a simple construction and to obviate the generation of biasing and wrinkling in traveling by continuously increasing the length in the circumferential direction of the inner peripheral surface of the belt from the central part of the body toward both ends. CONSTITUTION:The semiconductive endless belt 9 consisting of a thermoplastic sheet is formed to such a shape that the inside diameter D2 of the central part 9b is set at -0.1 to -1.0% size with respect to the inside diameter D1 of both right and left ends 9a, 9c in a transverse direction. Namely, the belt is so formed that the length in the circumferential direction of the inner peripheral surface of the belt itself increases continuously from the central part toward both ends. The endless belt 9 obtd. in such a manner is put on two pieces of rollers and the elongation stresses acting on the respective parts in the transverse direction of the belt are measured. As a result, the stress is large in the central part 9b and is the smaller the nearer the both ends 9a, 9c. Then, a failure, crack, etc., are not generated in both ends even if this belt is used over a long period of time. In addition, the generation of wrinkles in the central part is decreased and image defects are eliminated. |
