Patent attributes
A tire vulcanization mold cleaning method for cleaning a molding surface of a sector of the tire vulcanization mold for molding a tread portion of a pneumatic tire by using plasma created in an atmosphere of a reaction gas which chemically reacts with dirt attached to the molding surface of the sector. The method comprises the steps of placing the sector on a electrode table in a cleaning tank with the molding surface of the sector facing a discharge electrode, supplying the reaction gas to the cleaning tank while pressure in the cleaning tank is reduced, supplying a high-frequency power to the discharge electrode to create the plasma between the discharge electrode and the molding surface of the sector, and applying to the electrode table a high-frequency voltage having a frequency lower than a high frequency wave supplied to the discharge electrode to make the electrode table generate a negative self-bias.