| 摘要 |
PURPOSE:To provide a mold for a pneumatic tire reduced in production cost by reducing the number of vent holes, capable of simplifying maintenance work and the work removing the spew on the surface of a vulcanized tire and capable of easily and certainly discharging the gas between the molding surface of the mold and the surface of a green tire. CONSTITUTION:In a mold for a pneumatic tire used in a vulcanizing process, a plurality of projections 3 each having a diameter of 2.5-5.0mm and a height of 0.3-1.0mm are provided to at least one of the molding surfaces of a mold 1 coming into contact with the outer surfaces of the tread and side walls of the pneumatic tire to mold the same and the area ratio of the projections 3 per the unit area of the molding surfaces of the mold of the outer surfaces of the tread and side walls of the tire is set to 20-40%. By this constitution, the flow of rubber is improved and the number of vent holes can be reduced to 1/3-1/5 as compared with the usual number of vent holes. |
