| 摘要 |
PURPOSE: To prevent a raw material from flowing out to a parting line by specifying the individual cross-sectional area of at least one fine hole provided to the end part in the longitudinal direction of a cavity and the total cross-sectional area thereof. CONSTITUTION: The outer diameter of the cross-sectional area containing the rubber part of the cavity 3 formed when upper and lower molds 1, 2 are clamped is set to 5-100mm in a toner feed roller used in a copier or the like and set to l-20mm in a contact roller used in a switch or the like. Fine holes 4 are provided to the end part in the longitudinal direction of the cavity 3. The individual cross-sectional area of the fine holes 4 is set to 0.01-30mm<2> and the total cross-sectional area thereof is set to 1-30% of the cross-sectional area of the cavity 3. Herein, in place of the fine holes 4, gaps 7 wherein the individual cross-sectional area thereof is 0.01-100mm<2> and the total cross-sectional area thereof is 1-30% of the cross-sectional area of the cavity may provided between the outer peripheral part of a core 5 and the cavity 3. |
