Symptoms Sealed pronunciation or gassing (intermittent shaking). The static ring is bitten and eroded, resulting in a comet-like texture process that causes the outer edge of the narrow ring to be trimmed. Corrective measures Use wear-resistant materials as the end surface; improve the circulation conditions: hydrocyclone, external clean flushing; end surface deformation Symptoms When the pump is started, the seal leaks and the amount of leakage changes over time.

Corrective measures Natural aging deformation, re-grind; improper assembly, re-assemble carefully; poor alignment of the pump and bearing damage, adjust the pump. Coking High-temperature hydrocarbons often experience coking failures. The hard ring is thermally cracked.Common causes of seal failures in general mechanical seal analysis are usually obtained through analysis of the process experienced in use. Gently grind the end face on the platform, showing signs of deformation. The sealing life is short.

Dry operation There is insufficient or no liquid between the end faces. Vaporization (flashing) When the friction heat of the sealing surface accumulates, the liquid film between the end surfaces will locally boil. When the pump is stopped, the liquid viscosity increases due to the drop in temperature, which causes problems in restarting the pump. a. The rubber ring is hardened. Graphite ring powder accumulates on the outside of the Gland. Symptoms: Carbon graphite particles come off the end surface; the hard ring has polishing marks; graphite particles remain in the small gaps.

There is graphite dust accumulation at the inner edge of the end face. Corrective measures Check seal design parameters; improve circulation conditions. Symptoms Solid particles remain or accumulate on end faces and small gaps. Seal leakage and gel freezing. The graphite ring has record grooves. c. Corrective measures Choose balanced seals; choose hard materials with high thermal conductivity; check exhaust conditions; improve circulation conditions. Stable dripping on the sealing surface.

Abrasive wear The medium contains abrasive solid particles. Symptoms The stationary ring has severe wear and grooves. f. Pump and (or) shaft vibration.There are traces of polishing on the surface of the hard ring, or radial cracks (hot cracks) and discoloration. Seal screams while working.

Gas shock (spatter and splash) during sealing work. g. When the leakage of the liquid film is small, the air side of the seal will have a tendency to coke, which will prevent the end face from following and cause end face wear. Blister The shear stress between the ends of the high-viscosity liquid exceeds the breaking strength of graphite. Corrective measures Check the circulation; use 15~30min PTFE coated fiberglass fabric steam preheating or ※low pressure steam insulation

Among them, filling modification is a simple and effective method, which can not only maintain its advantages, but also use the compound effect to improve and overcome the defects of pure PTFE and improve its comprehensive performance.

Generally, there are four basic principles for selecting the filler: The filler is stable under sintering conditions of 380 ~ 400 cC, and is not compatible with or with PTFE The contacted metal or fluid reacts; ②The particle size is small and can be mixed evenly with PTFE powder; ③The filler does not absorb moisture and will not cluster by itself under sintering conditions; ④It can improve the mechanical strength and wear resistance of PTFE or improve Thermal conductivity, reduction of linear expansion coefficient, etc.

However, its low strength, wear resistance, creep resistance, and poor thermal conductivity have limited its wide application. The performance of the modified PTFE composite material is closely related to the type, content and molding process of the filler.

At present, in order to improve the Toaster Bag Manufacturers mechanical properties of PTFE composite materials, modification methods such as filling modification, surface modification and blending modification are usually used to meet people's requirements.PTFE is a high-molecular polymer with excellent performance, and its applications involve aerospace, petrochemical, machinery, electronics, construction, light textile and other industrial sectors. Adding different fillers to PTEF can significantly improve its tensile properties, impact properties, hardness or wear resistance

At present, the material handling is still not fully mature, and the material has some absorption after operation, which is under study. The disadvantages of are: (1) Intraoperative shaping is required.Compared with silicone rubber, expanded polytetrafluoroethylene Gore-Tex as a rhinoplasty material has the following advantages:  (1) It is softer than silicone rubber and is more natural after surgery.

Rhinoplasty materials can be divided into three categories: autologous materials, foreign materials or heterogeneous materials, and tissue substitutes. It is non-toxic, non-carcinogenic, non-teratogenic.Rhinoplasty is one of the common operations in plastic and cosmetic surgery.(3) The tissue can grow into the material, and the long-term fixation is better.　　

Due to insufficient hardness, the effect of supporting the columella and tip of the nose is not good. There are two commonly used ones: willow-shaped ;-shaped.Rhinoplasty using tissue substitutes (biomedical materials) is currently the most commonly used method. Silicone rubber can be pre-made into nasal prostheses with various shapes and models such as nose tip, nose alar and columella.(3) It is necessary to prevent the appearance change before the postoperative healing.(2) There is no 'transparency' like silicone rubber.　　

PTFE is resistant to high and low temperatures, has good chemical stability, corrosion resistance, and histocompatibility. Rhinoplasty is only to improve appearance, not necessary to treat diseases, so it should be used with caution. The chance of getting out due to excessive tension is low. Autologous materials include autologous costal cartilage, iliac bone, etc.Allogeneic or xenogeneic materials refer to bone or cartilage materials of other humans or animals, such as cattle nasal septal cartilage.

After being implanted in the body, a mild transient inflammatory reaction appeared locally, and a thin layer of fibrous cyst was formed around it later. It is the most widely used BBQ grill mat Manufacturers and effective material in rhinoplasty. The disadvantages are surgical scars and structural defects in the sampling area, which are also affected in function., which have the advantages of no risk of rejection for life, and excellent compatibility with nasal tissues.

Once postoperative infection occurs, the prosthesis must be removed to cure. Commonly used materials (and prostheses) are introduced as follows: Silicone rubber has good elasticity, easy to shape, good chemical inertness, non-toxic, non-carcinogenic, non-teratogenic, and good histocompatibility.The requirements for surgical disinfection are more stringent

The chlorotrifluoroethylene-vinyl ether copolymer is a strictly alternating copolymer ; and the stability of the molecular chain is poor because of the monomer competition rate. The molecular structure of the chlorotrifluoroethylene-vinyl ester copolymer is a non-strict alternating copolymer , and there are continuous vinyl ester copolymerized fragments.

The chain link also reduces its fluorine content to about 25%. Due to the further increase in fluorine content (>35%), tetrafluoroethylene-vinyl ether coatings have better weather resistance, chemical resistance, corrosion resistance and antifouling properties than trifluorotype coatings. Tetrafluoroethylene-vinyl ether has no chlorine atoms in the fluoroolefin chain link, so its effect in the field of corrosion prevention is improved.

Although the fluorine content is only about 1% lower than the chlorotrifluoroethylene-vinyl ether copolymer, its aging resistance is much worse, and it can only resist artificial aging to 2000-3000 hours, which is more than 1000 hours. At present, almost all domestic fluororesins on the market are such fluororesins, and the fluorine content is only 23. This is where the chemical resistance and weather resistance are poor.

Next, I will explain the difference between tetrafluororesin and trifluororesin in normal temperature curing fluorocarbon coatings for steel structure coating.Room temperature curing FC-S202 fluorocarbon coating adopts Zeffle GK-570 tetrafluoroethylene-hydrocarbyl vinyl ether fluorocarbon resin of Daikin Chemical of Japan as the film-forming material, which can ensure the 20-year outdoor service life of the coating.5%.

Nowadays, the most commonly used fluoroolefin-ethylene multi-element copolymer FEVE resin in room temperature curing fluorocarbon coatings has four categories, chlorotrifluoroethylene-vinyl ester multi-element copolymer, trifluorochloroethylene-vinyl ether multi-element copolymer, tetrafluoroethylene Ethylene-vinyl ester multi-element copolymer, tetrafluoroethylene-vinyl ether multi-element copolymer. The second is to ensure the quality of construction.

The vinyl ether fragments are Wholesale PTFE Fusing Belts Manufacturers shielded and surrounded by the more stable chlorotrifluoroethylene fragments, so the aging resistance is good, the fluorine content is about 26%, and the artificial aging resistance exceeds 4000 hours

It can withstand high temperature to 300°C in a short time, and generally can be used continuously between 240°C and 260°C. Under a certain load, it has the dual advantages of wear resistance and non-sticking. After Teflon spraying, the unique insulation and anti-static properties are widely used in the electronics industry.Teflon spray high-performance special coating is a fluorine coating based on polytetrafluoroethylene resin, the English name is Tefion.

After the inner wall of the bearing is treated, it has self-lubricating and wear resistance 【Corrosion toaster bags resistance application】[Resistant to high and low temperature applications] Teflon is hardly corroded by chemicals and can protect parts from any kind of chemical corrosion. (all are the transliteration of Teflon). It has remarkable thermal stability. Short downtime, saving working hours and improving work efficiency  [Teflon wear resistance] It has excellent wear resistance under high load. It can work at freezing temperature without embrittlement and does not melt at high temperature.　　 　　

[Electrical insulation application] After being coated with Teflon special industrial coating, it has good insulation and high resistivity on the surface, which can play an anti-static effect. Teflon spray coating is a rare high-performance coating that combines heat resistance, chemical inertness and excellent insulation stability and friction. It has a comprehensive advantage that other coatings can’t compete.

It has excellent chemical stability, excellent non-stick characteristics, and high operating temperature. Teflon spray is divided into several basic types: PTFE, FEP, PFA, ETFE: 1.html Teflon coating, Teflon coating,. Teflon spray has excellent heat resistance and low temperature resistance. Teflon sprayed PTFE: PTFE (polytetrafluoroethylene) non-stick coating can be used continuously at 260°C, with a high operating temperature of 290-300°C, extremely low friction coefficient, good wear resistance and excellent chemistry stability. (In addition, there are special coatings, which can make the coating conductive). 

Its application flexibility makes it Can be applied to almost all shapes and sizes of products. It does not stick to water or oil, and it is not easy to stick to solutions such as sticky during production operations. 200°C.kytfl. Teflon spray ETFE: ETFE is a copolymer of ethylene and tetrafluoroethylene. The advantage of PFA is that it has a higher continuous use temperature of 260°C, stronger stiffness and toughness, and is especially suitable for anti-sticking and chemical resistance applications under high temperature conditions.

A small amount of dirt can be removed by simply wiping. 3. Because of the pronunciation, it is usually called Teflon, Teflon, Teflon, Teflon spray, etc. 2. Teflon sprayed PFA: PFA (perfluoroalkyl compound) non-stick coating melts and flows during baking to form a non-porous film like FEP. The resin is a tough fluoropolymer that can form a highly durable coating with excellent chemical resistance and can be used in Work continuously at 150°C

The transition temperature of 19°C is very important for processing PTFE blanks. This characteristic determines that PTFE cannot be processed by high temperature melt extrusion commonly used in general thermoplastic resins, but similar The pressure and sintering method of powder metallurgy is combined.

During the process of molding the blanks with PTFE powder resin, if the temperature of the pressed blanks is lower than 19°C, when the finished blanks are at 19°C At a temperature above ℃, the lattice distance will change, which is the deformation of the blank product, which will eventually cause the internal cracking of the blank product. 327℃ is the melting point of polytetrafluoroethylene. Therefore, the temperature for processing the PTFE blank is generally selected between 19 and 29 ℃. Therefore, it has been widely used in the wire and cable industry. The following is a brief introduction to the performance of PTFE..

Strictly speaking, above this temperature, the crystalline structure disappears, and the polytetrafluoroethylene transforms into a transparent amorphous gel state, and the volume ratio increases by PTFE coated fiberglass tape Manufacturers 25%. Its crystal lattice distance changes at 19℃, 29℃, 327℃, and there are turning points, that is, the volume of the crystal will change at this temperature.Polytetrafluoroethylene is abbreviated as F-4 (TFE or PTFE), which is polymerized by tetrafluoroethylene. It is an unbranched linear polymer with a completely symmetrical molecular structure.

Therefore, during the sintering process, the heating rate near the melting point must be slow to make the product inside and outside The temperature is uniform, otherwise there will be stress inside the product, or even cracking in severe cases. The melt viscosity in the glue state is still as high as 1010~1011Pa\u0026middot;S at 360℃, and still cannot flow. This structural feature makes PTFE have a higher frequency range and high and low temperature range, excellent chemical stability, high electrical insulation and weathering resistance.

This is that the CC main chain is not attacked by ordinary active molecules, and the fluorine atoms on the main chain of the macromolecule are symmetrical with each other, so the electrical properties Neutralization, the whole molecule has no polarity. Physical properties Polytetrafluoroethylene is a polymer with high crystallinity. Among the known polymer bonds, the CF bond is One of the strongest bonds, most of the main carbon chain is tightly surrounded by fluorine atoms. Due to the low thermal conductivity of PTFE, the volume changes greatly at the temperature above and below the melting point.