Manufacturing method of sealing gasket and its used pressing die structure

Abstract

Provided is a gasket manufacturing method capable of molding a unmolded structure without damaging a resin film material by excluding the gap around a cavity in the pressing state of a pressing machine and capable of easily obtaining a resin coated gasket excellent in capacity at a low cost, and a press mold structure used in the method. An elastic member 13 facing to a cavity 30 is arranged in one mold 11 in a pressing machine and quickly brought into close contact with another mold 12 at the time of mold clamping to eliminate the gap between the mating surfaces 14 around the cavity 30 so as not to cause a state that a rubber material goes toward the gap by an increase in the internal pressure of the cavity 30. The film material can be prevented from being torn by the pressure from the rubber material ready to go toward the gap, and the rubber material and the film material are together molded under pressure to efficiently manufacture a single wrapping type gasket excellent in sealability. The shortening and cost reduction of a manufacturing process can be achieved.

Description

technical field [0001] The present invention relates to a method for producing a sealing gasket in an electrolytic cell for alkali metal chloride electrolysis of an ion exchange membrane method for electrolyzing an aqueous solution of alkali metal chloride to produce chlorine and alkali metal hydroxide It is arranged between the flange surface of the anode chamber and the cation exchange membrane. In particular, the present invention relates to a method of manufacturing a gasket capable of properly disposing a resin thin film having excellent corrosion resistance on the surface of the gasket, and to a press mold structure used in the method. Background technique [0002] In an electrolytic cell that uses an ion-exchange membrane to electrolyze an aqueous alkali metal chloride solution, as an electrolytic cell for producing high-purity alkali metal hydroxide with high current efficiency, the ion-exchange membrane and gasket are installed so that the A filtration pressurized ...

AI Technical Summary

Problems solved by technology

[0010] If, in the case where the fluororesin film is placed in the cavity together with the unvulcanized rubber, on the side of the rubber surface, facing the gap of the mold clamping surface, there is a problem that the extremely thin fluororesin film cannot withstand the pressure of the mold clamping, The pressure generated by the unvulcanized rubber moving toward the gap under pressurization, the fluororesin film is damaged, and the rubber leaks into the gap, and there is a very high risk that the final molded product will become a defective product with rubber exposed.

In the past, such integral molding has not been performed

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