What is fluoroplastic?

Plastics that contain fluorine atoms in their molecular structure are collectively referred to as fluoroplastics. Fluoroplastics consist of fluorine-containing monomers. Monomers such as tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, vinylidene fluoride and vinyl fluoride are prepared by homopolymerization or copolymerization. With the continuous development of polymer technology, the variety of fluoroplastics is gradually increasing, and the scope of application is expanding. Due to the fluorine atom contained in the molecular structure of fluoroplastics, it has many excellent properties, such as excellent electrical insulation, high heat resistance, outstanding oil resistance, solvent resistance and abrasion resistance, good moisture resistance and low temperature resistance . Therefore, fluoroplastic products occupy an important position in the national defense, electromechanical, metallurgical, petrochemical and other industrial sectors.

In the production of wire and cable, the commonly used fluoroplastics include polytetrafluoroethylene, polyperfluoroethylene propylene, polyvinylidene fluoride, tetrafluoroethylene and ethylene copolymers, etc., which are used to manufacture various heat-resistant and high-temperature insulated wires. ) Well cables, geological exploration cables, heating cables, F-class and H-class motor lead wires, radiation-resistant wires, electromagnetic wires, radio frequency coaxial cables, etc.

The development history of fluoroplastics

The fluorinecontaining plastic molding and processing industry in my country began to develop in the early 1960s. It was mainly used in the national defense industry in the 1960s and 1970s. After the 1980s, the military-civilian integration and popularization and application work were strengthened, so that the fluorine-containing plastic molding and processing industry was rapidly developed. develop. After 40 years of hard work, our manufacturers have basically mastered the main forming processing methods. Such as molding, isostatic molding, extrusion molding (plunger extrusion molding, screw extrusion molding and paste extrusion molding), transfer molding, rotational molding, bulk molding, dipping, spraying, electroless plating, blow molding , Injection molding and other molding processing methods. Fluoroplastic products are widely used in various fields of the national economy.

Performance characteristics of fluoroplastics

   The performance characteristics of fluoroplastics: polytetrafluoroethylene and perfluoro (ethylene-propylene) copolymer (FEP) are completely composed of carbon atoms and fluorine atoms, while polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF) molecules It also contains hydrogen atoms, and polychlorotrifluoroethylene also contains chlorine atoms. The excellent performance of fluoroplastics is achieved by the high binding energy between carbon atoms and fluorine atoms.

1. Thermal properties Fluoroplastics have flame retardancy and excellent heat resistance. The continuous use temperature of PTFE and PFA can reach 260¡ãC, and it can be used at 300¡ãC for a short period of time. The use temperature of FEP is 60¡ãC lower than them. The higher PCTFE can be used at 120¡ãC. If fluoroplastics are used at high temperatures for a long time, they will cause changes in crystallinity, so special attention must be paid when manufacturing equipment linings.

2. Chemical resistance Fluoroplastics have excellent chemical resistance and solvent resistance, especially PTFE, PFA, FEP, etc., which are not corroded by acids, alkalis, and solvents. However, molten alkali metals, fluorine, and trifluorochlorinated hydrocarbons have varying degrees of influence on them. PCTFE, ETFE, PVDF, etc. are slightly less resistant to chemicals in fluoroplastics, but they have much better corrosion resistance than other plastics.

3. Electrical properties The electrical properties of fluoroplastics, especially high-frequency electrical properties, are hard to match with other materials. The molecules of PTFE, FEP, and PFA have very low polarity, small changes in a wide temperature and frequency range, stable relative dielectric constant, low dielectric loss, and excellent electrical insulation. Among them, PVDF also has specific piezoelectricity and pyroelectricity, which can be used to make piezoelectric materials.

4. Mechanical properties The increase in hydrogen and chlorine atoms in the fluoroplastic molecule increases its tensile strength. The embrittlement temperature of PTFE and PCTFE is extremely low, showing excellent low temperature performance. PTFE has a low coefficient of friction and specific self-lubricating properties. However, PTFE has disadvantages such as large abrasion and cold flow. Various fillers can be used to improve wear resistance and overcome cold flow.

5. Non-stickiness Fluoroplastics have specific non-stickiness. In particular, molecules such as PTPE, FEP, and PFA have high fluorine content, and the surface contact angle is very large, making the liquid on the surface of the fluoroplastic product spherical. It is not easy to bond with resin, so it is often used to make non-sticky layer on the surface of cookware.

6. Weather resistance All types of fluoroplastics have excellent weather resistance, and their various properties remain unchanged even if exposed to harsh temperatures for a long time.

7. Hydrophobic Fluoroplastics have low water absorption, especially PTFE. Its water repellency can be used to manufacture breathable and impermeable composite fabrics and other equipment.