Daily Archives: 02/04/2021

FEP resin, like PTFE, has a completely fluorinated structure. The difference is that part of the fluorine atoms in the main chain of PTFE are replaced by trifluoromethyl (-CF3).

The structural formula is as follows:

It can be seen that although both FEP resin and polytetrafluoroethylene are composed of fluorocarbon elements, the carbon chain is completely surrounded by fluorine atoms, but FEP has branches and side chains on the main chain of its macromolecule.

This structural difference has no significant effect on the upper limit of the temperature range of the material under long-term stress. The upper limit temperature of FEP is 200°C, while the maximum use temperature of PTFE is 260°C. However, this difference in structure makes FEP resin have a fairly definite melting point and can be molded and processed by general thermoplastic processing methods, greatly simplifying the processing technology. This is not available in PTFE. This is the main purpose of modifying polytetrafluoroethylene with hexafluoropropylene.

If it is used as a shrink tube, you must choose a suitable tube, otherwise not only the desired effect will not be achieved, but also premature aging and failure may occur. The one I want to recommend to everyone here is the FEP pipe, which is a two-layer pipe made of fluoroplastics and has excellent performance in all aspects.

If it is a shrink tube of general material, it will inevitably turn yellow after a period of use, resulting in a decrease in the light transmittance of the tube. But if the FEP tube is used as a shrink tube, the result is completely different.

After testing, it is found that FEP tube has good weather resistance and strong ability to withstand ultraviolet rays. Therefore, even if it is used for a long time,FEP tube will not appear aging, deterioration, yellowing and other undesirable phenomena.

The wall thickness of the FEP pipe is very uniform, and the difference in rupture strength is generally small, so even if it is ruptured, there will be no splashing, which greatly improves the safety.

But this kind of fluorine plastic raw material product has a characteristic, it must undergo secondary processing to get the desired product. In fact, FEP pipe is processed in this way, and the secondary processing technology used is inflation.

Due to the processing characteristics of fluoroplastics, some products are difficult to form at one time and require corresponding secondary processing technology. In addition to the inflation technology used to make FEP pipes, it also includes cutting, welding, lining and other technologies.

The cutting method here is similar to the metal cutting method, but it should be noted that the blank body must be placed for 24 hours before cutting; welding is done in a special clamp, and a certain pressure must be applied Only possible; the main lining is made of ferrous metal, mainly for anti-corrosion effect.

FEP This material does not ignite and prevents the spread of flames. It has excellent wear resistance, low friction coefficient, and can be used from low temperature to 392F. The material can be made into granular products for extrusion and molding, used as powder for fluidized bed and electrostatic coating, and can also be made into water dispersion. Semi-finished products include films and plates. Rod and single fiber. Its main purpose is to make linings for pipes and chemical equipment, surface layers of drums and various wires and cables, such as aircraft hook wires, booster cables, alarm cables, flat cables and oil well logging cables. FEP film has been used as a thin coating for solar collectors.

Polyperfluoroethylene propylene FEP or F46 is a copolymer of tetrafluoroethylene and hexafluoropropylene. The content of hexafluoropropylene is about 15%. It is a modified material of polytetrafluoroethylene.

F-46 resin not only has similar characteristics to PTFE, but also has good processing properties of thermoplastics. Therefore, it makes up for the deficiencies of the difficult processing of PTFE, making it a material that replaces PTFE, and is widely used in the production of wires and cables for electronic equipment transmission wires used under high temperature and high frequency, connecting wires inside electronic computers, Insulation layer of aerospace wires and special purpose installation wires, oil pump cables and winding wires of submersible motors.

According to processing needs, F-46 can be divided into three types: pellets, dispersions and paints. Among them, the pellets can be used for molding, extrusion and injection molding according to their melt index; the dispersion is used for dipping and sintering; the paint is used for spraying, etc.

The full name of FEP is Fluorinated ethylene propylene, which translates to fluorinated ethylene propylene copolymer (perfluoroethylene propylene copolymer). English trade name: Teflon* FEP, is a class of chemical substances.

FEP is a copolymer of  tetrafluoroethylene and  hexafluoropropylene.

FEP crystal melting point is 304℃, density is 2.15g/CC (grams/cubic centimeter).

FEP  can be applied to soft plastics, and its tensile strength, abrasion resistance, and creep resistance are lower than many engineering plastics.

It is chemically inert and has a low dielectric constant over a wide range of temperature and frequency (2.1)