Fluoroplastic-metal valve element and molding technological method thereof

Abstract

The invention discloses a fluoroplastic-metal valve element and a molding technological method thereof. The fluoroplastic-metal valve element comprises a valve element metal base body and fluoroplastic attached to the top of the valve element metal base body. The valve element metal base body comprises a valve head and a valve rod. By the adoption of the molding technological method, the valve head is filled with melted fluoroplastic. After a fluoroplastic transitional layer tightly fastened to the metal base body is manufactured between the fluoroplastic and the metal base body, the hot-press molding technological method is adopted, the adhesion strength between the fluoroplastic and the fluoroplastic transitional layer and between the fluoroplastic transitional layer and the metal base body is guaranteed and reaches over 17 MPa, and the sealing performance is reliable.

Description

technical field [0001] The invention belongs to the technical field of plastic molding technology and machinery manufacturing, and relates to a manufacturing technology of a fluoroplastic-metal valve core. Background technique [0002] In the medium-resistant valves used in rocket engines, most of the valve cores adopt a design structure in which fluoroplastics with strong corrosion resistance are embedded in metal substrates. At present, the methods of fluoroplastics embedded in metal substrates are divided into cold extrusion and hot pressing. The cold extrusion method is to squeeze the fluoroplastic plastic block into the valve head part without heating. Take the polytetrafluoroethylene cold extrusion valve core as an example. After cold extrusion, the polytetrafluoroethylene is filled behind the valve head part. It can only be cold-bonded with the metal, then rolled and closed to form the valve core. During the manufacturing process, it relies on the cold flow of fluorop...

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Problems solved by technology

The cold extrusion method is to squeeze the fluoroplastic plastic block into the valve head part without heating. Take the polytetrafluoroethylene cold extrusion valve core as an example. After cold extrusion, the polytetrafluoroethylene is filled behind the valve head part. It can only be cold-bonded with the metal, then rolled and closed to form the valve core. During the manufacturing process, it relies on the cold flow of fluoroplastics for filling. Fluoroplastics cannot be tightly fitted with the metal matrix. There are gaps between the fluoroplastics and the metal matrix, which is easy to Phenomenon such as liquid penetration, poor reliability

The hot pressing method is to put the metal matrix of the valve core that has been sandblasted, cleaned and dried into a hot pressing mold, add fluoroplastics and place it in a hot pressing machine, and then prepare it by melting, cold pressing, shaping, and demoulding. Take FEP-metal spool as an example. During this process, the FEP melt in a viscous flow state has a high viscosity and cannot completely infiltrate the resin melt into the groove of the metal blasting surface, so it cannot Obtain a fluoroplastic-metal bonding surface with high bonding strength

Zhu Jun et al. (CN201510050686) improved the bonding strength of fluoroplastics to metal by coating an adhesive promoter, but the valve core prepared by using this adhesive is reliable in acid and alkali aqueous solution and unsymmetrical dimethylhydrazine and other media. Poor sex

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