In today’s industrialized countries, the annual economic loss caused by corrosion accounts for about 4% of the total national economic output. A considerable number of accidents in chemical production is caused by chemical reactions caused by equipment corrosion and medium leakage.
It can be seen that the damage caused by corrosion is serious and has attracted people’s attention. PTFE material overcomes the shortcomings of ordinary plastics such as poor corrosion resistance and has become the main corrosion-resistant material in the petroleum, chemical, textile and other industries.
Anti-corrosion performance of PTFE coating material:
- The highest operating temperature is 300℃.
- Continuous use temperature 260℃.
- The sintering temperature used for PTFE coating is 380～420℃.
- PTFE can only be used for a lining when used in corrosion protection, not suitable for coating.
- Very low coefficient of friction, good wear resistance, and excellent chemical stability.
- Corrosion resistance: PTFE is hardly corroded by chemicals and can protect the product from any kind of chemical corrosion.
Application of PTFE Microfiber Membrane in Chemical Industry
The PTFE microfiber membrane is prepared by a biaxial stretching process. It has a microstructure with interlaced fibers, forming a certain shape and size of pores, and has high porosity.
Therefore, it has excellent filtration performance, good air permeability and It can retain dust particles and is widely used in air filtration, medical and food filtration.
Preparation method of PTFE microfiber membrane
1. Melt stretching method
Melt-stretching method The melt-stretching method is to blend PTFE and co-extruding agent, heat and melt, extrude to form a sheet-like sample, and then heat-stretch to form a microporous film.
According to the different stretching directions, it is divided into unidirectional stretching and bidirectional stretching. The microporous structures of the products obtained by the two stretching methods are different: the pores of the PTFE microfiber membrane prepared by the uniaxial stretching method are oblong, and the pores of the PTFE microfiber membrane prepared by the biaxial stretching method are spherical.
2. Thermally induced phase separation method
Thermally induced phase separation is an emerging method for preparing microfiber membranes in recent years. In this method, PTFE is blended with some compounds, heated to dissolve PTFE in it to form a uniform system, phase separation occurs during the cooling process, and the product obtained by cooling is stretched to obtain a PTFE microfiber membrane.
The microfiber membrane prepared by thermally induced phase separation is thinner, the pore size is smaller, and the micropore distribution is more uniform. However, the thermally induced phase separation method requires a large amount of solvents, which will cause environmental pollution, and the process is relatively complicated, so industrial production has not yet been realized.
PTFE microfiber membrane has stable properties and low surface energy, and can be used as a microfiltration membrane in industry. When the PTFE microfiber membrane is used in the dust collector of a cement plant, the air handling capacity will be increased by 15% to 30%, which can achieve high-throughput continuous work, and the PTFE membrane has no adhesion to the cement dust, and the dust can quickly pass through the dust collector , Reducing the dust explosion rate of the factory.
Application of PTFE Gasket in Chemical Industry
PTFE gaskets are made of PTFE as the main material. Because of its high corrosion resistance, stable physical properties, and high and low temperature resistance, it has achieved good sealing performance and is widely used in petroleum and chemical industries. Applicable media include water, oil, acid solution, alkali solution and almost all chemical components.
Taking into account the high price of raw materials for chemical products, any leakage will bring great losses to users. Chemical products are more flammable and explosive, and leakage is likely to cause immeasurable and serious losses such as explosions, fires, and casualties. Therefore, the petroleum and petrochemical industry places such high requirements on sealing products.
The medium in the petroleum and petrochemical the industry is mostly a variety of liquids and gases with different corrosive properties, such as aromatic hydrocarbons, rust inhibitors, sour gas, drilling fluid, seawater, carbon dioxide, hydrogen sulfide, etc., and these media are often mixed together and have high temperatures The characteristics of high pressure require the use of sealing products such as PTFE gaskets to have excellent quality and good chemical properties.
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