What is a PTFE Tape ?

- Feb 22, 2019-

The raw material chemical name is Teflon [1], ordinary white polytetrafluoroethylene tape is commonly used in HVAC and water supply and drainage, and natural gas pipelines also have special Teflon tape. In fact, the main raw materials are polytetrafluoroethylene. Vinyl fluoride, but some processes are different.

The raw material belt is made of imported materials and advanced technology. It has excellent quality and complete specifications to meet the requirements of different customers in different industries. The product has excellent insulation, strong chemical stability and good sealing performance, and is widely used in various fields such as machinery, chemical industry, metallurgy, electric power, shipbuilding, aerospace, medicine, electronics and so on.

definition

The raw material belt is also called PTFE strip, and the polytetrafluoroethylene is a polymer of tetrafluoroethylene, which is abbreviated as PTFE.

basic structure

The basic structure of polytetrafluoroethylene is - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 -.

Molecular weight

The relative molecular mass of PTFE is relatively large, hundreds of thousands of low, more than 10 million high, and generally millions (degree of polymerization is 104 orders of magnitude, while polyethylene is only 103). The crystallinity is generally 90 to 95%, and the melting temperature is 327 to 342 °C. The CF2 units in the PTFE molecule are arranged in a zigzag shape. Since the radius of the fluorine atom is slightly larger than that of hydrogen, the adjacent CF2 units cannot be completely cross-oriented, but form a helical twisted chain, and the fluorine atoms are almost covered. The surface of the entire polymer chain. This molecular structure explains the various properties of polytetrafluoroethylene. When the temperature is lower than 19 ° C, a 13/6 helix is formed; at 19 ° C, a phase change occurs, and the molecules are slightly untwisted to form a 15/7 helix.

Although the cleavage of carbon-carbon bonds and carbon-fluorine bonds in perfluorocarbons requires absorption of energy 346.94 and 484.88 kJ/mol, respectively, the depolymerization of polytetrafluoroethylene to produce 1 mol of tetrafluoroethylene requires only 171.38 kJ of energy. Therefore, at the time of pyrolysis, the polytetrafluoroethylene is mainly depolymerized into tetrafluoroethylene. The weight loss rate (%) of polytetrafluoroethylene at 260, 370, and 420 ° C was 1 × 10 -4 , 4 × 10 - 3 , and 9 × 10 - 2 , respectively. It can be seen that polytetrafluoroethylene can be used at 260 ° C for a long time. Due to the high-temperature cracking, it also produces highly toxic by-products such as fluorophosgene and perfluoroisobutylene. Therefore, special attention should be paid to safety protection and to prevent exposure of PTFE to open flames.

Performance

Polytetrafluoroethylene (F4, PTFE) has a series of excellent performance: high temperature resistance - long-term use temperature of 200 ~ 260 degrees, low temperature resistance - still soft at -100 degrees; corrosion resistance - resistant to aqua regia and all organic solvents; Weather resistance - extremely long aging life in plastics; high lubrication - with a very small friction coefficient in plastics (0.04); non-sticky - with minimal surface tension in solid materials without adhering to any substance; non-toxic - physiological Inert; excellent electrical properties, ideal for Class C insulation. PTFE materials are widely used in important departments such as defense industry, atomic energy, petroleum, radio, electric machinery, and chemical industry.

product

PTFE bar, pipe, sheet, turning sheet.