Preparation method of reinforced polytetrafluoroethylene for high/medium-pressure valve sealing element

Abstract

The invention relates to a preparation method of a reinforced polytetrafluoroethylene for a high / medium-pressure valve sealing element. The method comprises the following steps of material preparation, drying, material mixing, die filling for compaction molding, sintering, mechanical machining and inspection for warehouse entering. The reinforced polytetrafluoroethylene comprises the following components in parts by mass: 0.5 to 1.5 parts of high-strength carbon nanofibers, 3 to 5 parts of molybdenum disulfide powder, 20 to 25 parts of tin bronze powder and 65 to 75 parts of polytetrafluoroethylene powder, wherein one or more of 5 to 10 parts of reinforced glass fibers being from 3mm to 5mm in length, 10 to 15 parts of silicon dioxide powder, 1 to 2 parts of graphite powder, 1 to 3 parts of white corundum powder and 1 to 3 parts of green silicon carbide powder can be added into the reinforced polytetrafluoroethylene; the reinforced polytetrafluoroethylene further comprises a dispersant 5040, the weight of which accounts or 1% of the total weight of all raw materials. The polytetrafluoroethylene taken as a base material is easy to available and low in cost; the mass percent of copper in the reinforced polytetrafluoroethylene is less than one fourth, so that the copper consumption is greatly reduced and the machining quantity is also reduced, namely, more importantly, the quantity of machining wastes is reduced. The abrasion resistance and the self-lubrication of a blank are improved by adding the molybdenum disulfide into the reinforced polytetrafluoroethylene, so that the sealing ability of a workpiece is greatly improved while the service life of the workpiece is prolonged. The workpiece has the performance of corrosion resistance and aging resistance and has no conductivity. Thus, the reinforced polytetrafluoroethylene is very suitable for the workpiece with a certain insulation requirement.

Description

technical field [0001] The invention relates to a composite new material, that is, a method for making reinforced polytetrafluoroethylene used for high and medium pressure valve seals. By adding required materials to the polytetrafluoroethylene (PTFE) used as valve seals, It is used to improve the performance of polytetrafluoroethylene, broaden the scope of application of polytetrafluoroethylene, so as to replace metal seals such as copper under certain conditions of use. Background technique [0002] Generally, the requirements for sealing materials are as follows: appropriate mechanical strength and hardness, good chemical stability, small friction, good wear resistance, good softness and elasticity combined with the sealing surface, good compactness, and not easy to seal. Leakage medium, easy material acquisition, convenient processing and manufacturing, cheap price and so on. In practice, there is no one material that can meet the above requirements at the same time,...

AI Technical Summary

Problems solved by technology

[0007] Adding tin bronze powder, high-strength nano-carbon fiber, and tin bronze powder are mainly to overcome the shortcomings of PTFE, such as low strength, large thermal expansion coefficient, and poor wear resistance. Molybdenum disulfide added to the ingredients improves the wear resistance and self-lubrication of the blank. ;