A polytetrafluoroethylene composite material for packing and method for preparing packing thereof

Abstract

The invention discloses a polytetrafluoroethylene composite material for packing and a method for preparing the packing. The polytetrafluoroethylene composite material for packing consists of the following components in parts by weight: polytetrafluoroethylene dispersion resin 100 Parts, 5-20 parts of molybdenum disulfide, 1-10 parts of tetraacicular zinc oxide, 1-10 parts of aluminum oxide, 1-5 parts of carbon nanotubes, 1-5 parts of clay; the method for preparing packing consists of the following steps Composition: (1) mix polytetrafluoroethylene dispersed resin and various fillers evenly; (2) add booster oil to fully mix and heat and mature; (3) press into billets; (4) push extrusion and calendering; (5) ) high temperature deoiling and stretching and shaping; (6) split into fibers and weave packing. The polytetrafluoroethylene packing of the present invention has excellent thermal conductivity and heat resistance, high temperature stress relaxation resistance, acid and alkali resistance, chemical reagents and self-lubrication performance, good sealing performance, long service life and less wear on equipment, It can be used for pumps or valves with high pressure, high temperature, high speed and dynamic sealing.

Description

technical field [0001] The invention belongs to the field of sealing materials, and in particular relates to a polytetrafluoroethylene composite material for packing and a method for preparing the packing. Background technique [0002] Packing (woven packing) is also called sealing packing, which is usually braided by softer wires, usually square or rectangular in cross-sectional area, and round strips are filled in the sealing cavity to achieve sealing. The stuffing seal was originally made of cotton and other fibers plugged in the leakage channel to prevent liquid leakage, and it was mainly used as a shaft seal for water lifting machinery. Due to the wide range of packing sources, easy processing, low price, reliable sealing and simple operation, it is still used today. Now packing is widely used in shaft seals of centrifugal pumps, compressors, vacuum pumps, mixers and ship propellers, piston pumps, reciprocating compressors, reciprocating shaft seals of refrigerators, a...

AI Technical Summary

Problems solved by technology

The current PTFE packing can improve a certain defect by adding specific fillers, but the overall performance needs to be improved. The high temperature performance, wear problems, and wear and corrosion problems of equipment have not been greatly improved, which affects the The sealing performance and durability of the packing and the service life of the equipment

CN 106594281 A discloses a polytetrafluoroethylene packing. The outer layer of the packing is made of polytetrafluoroethylene material, the inner core of the packing is made of silicon rubber, and the outer layer and the inner core are made of a polytetrafluoroethylene film. The core is isolated, so that it has good elasticity, can maintain good sealing performance, and can maintain good corrosion resistance at the same time, but because the outer layer is made of pure polytetrafluoroethylene, it is easy to wear and the upper limit of the service temperature is low

CN103574035 A discloses a polytetrafluoroethylene fiber packing, which is composed of the following components in parts by weight: 100 parts of polytetrafluoroethylene, 80-100 parts of graphite, 1-3 parts of isopropyl trioctanoyl titanate, 2-4 parts of harsh nickel; CN 1724607 A discloses a graphite-filled polytetrafluoroethylene fiber packing, the dispersed polytetrafluoroethylene resin accounts for 50%-82%, and the rest is natural graphite; both of them are obtained by adding a large amount of graphite Improve thermal conductivity, high-speed resistance and low creep performance, and the performance is better than that of pure PTFE fiber packing. However, due to the limitation of the characteristics of graphite itself, when used in environments with high requirements such as high strength, there are still Insufficient properties such as anti-wear and anti-extreme pressure

CN 108360260 A discloses a packing, a preparation method of the packing and the first impregnating liquid used for preparing the packing. The fluorine-containing polymer emulsion such as polytetrafluoroethylene added with functional filler additives is impregnated into the The surface of ramie fiber, flax fiber, aramid fiber, polyester fiber, acrylic fiber, carbon fiber or cotton fiber is dried to make packing, but due to the non-stickiness of fluorine-containing materials, when used in high-strength environments, fluorine-containing coatings Layers are easily detached from the fibers causing packing failure

CN 1464023 A discloses a filled polytetrafluoroethylene material for oil sealing parts and its preparation method, wherein the composition includes (the following amounts are parts by weight): 100 parts of suspended polytetraethylene resin, 5.8-6.8 parts of molybdenum disulfide, 8.7-20.5 parts of alkali-free glass fiber, 2.7-5.8 parts of graphite powder, mixed at high speed and then molded and sintered. Excellent performance and other characteristics, but this kind of seal made of polytetraethylene suspension resin can only be prepared by machining after molding and sintering, and the shape and volume are greatly limited, so it is limited by the shape and space where the equipment is used larger

Images