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. 

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