Many experts are optimistic about the demand growth of fluoroplastics in the wire and cable market. It is understood that fluoroplastics have many advantages, such as excellent electrical properties, low dielectric constant, high thermal stability, low flammability, low moisture absorption, stain resistance, excellent weather resistance, and excellent resistance to most chemicals. So many excellent properties make fluoroplastics play an important role in wire and cable. Experts at the meeting introduced that fluoroplastics have played an important role in many fields of my country's national economy.

In terms of wires and cables, fluoroplastics are mainly used in high-temperature compensation wires, high-temperature signal wires, Ethernet wires, industrial high-temperature power and control cables, high-temperature power and control cables for rail transit locomotives, and high-temperature heating cables. Fluorine plastic insulated variable frequency power cable is mainly used in iron and steel, metallurgy, petrochemical, power stations and other high temperature operation, the environment is bad place frequency conversion equipment electric energy transmission connection line. It is understood that the fluorine plastics commonly used in the wire and cable industry are mainly polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA) and so on. With the continuous development of the wire and cable industry, for example, the demand for high-temperature cables in the special industry is becoming increasingly strong, and the demand for fluoroplastics will increase. According to incomplete statistics, in the past 3 years, heat-resistant and high-temperature resistant cables have grown at a rate of more than 15% per year.

Special cable is a series of products with unique performance and special structure, which has the characteristics of high technical content, harsh use requirements and high added value. With the development of China's social economy and the construction of industrialization, the application field of special cable products has been greatly expanded. Fluoroplastics with excellent electrical properties, thermal stability and mechanical and physical properties have become a new type of cable material, making fluoroplastic cables become the spokesperson of special cables.

Currently used in the industrial field of fluorine plastic cable has the following four characteristics:

1, high temperature resistance level, the thermal stability of fluorine plastic makes fluorine plastic cable can adapt to 150~200 ℃ high temperature environment, at the same time, in the case of the same conductor section, fluorine plastic cable compared to PVC, XLPE insulated cable, can transmit more current;

2, excellent flame retardant properties, fluorine plastic oxygen index is high, such as the oxygen index is greater than 95, cable burning flame spread range is small, the amount of smoke produced is very small, subway, vehicles, high-rise buildings and other public places, in the event of a fire, people can have a certain amount of time to alienate, and not be smoked down by smoke, to win valuable rescue time;

3, excellent electrical performance, due to the low dielectric constant of fluorine plastic, so that the attenuation of fluorine plastic cable is less than other cables with the same structure, more suitable for high frequency signal transmission;

4. Stable mechanical and chemical properties, high chemical bond energy of fluoroplastics, high stability, excellent weathering resistance, corrosion resistance to acids, alkalis and organic solvents.

Even if fluoroplastics have such excellent electrical and mechanical properties, which are incomparable to PVC, XLPE, PE and other cables, due to the high price of fluoroplastics raw materials and the difficulty of cable production and extrusion process, toxic gases will be discharged during material extrusion in the production process, so the production cost of fluoroplastic cables is high and their market sales price is also high, greatly limits the market application prospects of the product, so reduce production costs become the main problem, and the reduction of production costs from the process control as the starting point, according to my yearsRecycling fluoroplasticsCable extrusion experience, will be introduced from the following aspects of the extrusion process note:

1. Selection of extrusion method

Fluoroplastic melt melt viscosity is extremely large, in the processing of thermoplastic fluoroplastics, it is not appropriate to use pressure extrusion, according to the melt has sufficient strength and allows stretching, so it can be used sleeve die extrusion production of fluoroplastic wire and cable.

2. Extrusion die

When casing die extrusion, the die is the most critical factor in the thermoplastic fluoroplastic extrusion process. Inappropriate dies may cause problems such as loose sleeves, melt fracture, surface ripples, and large fluctuations in outer diameter. Extrusion molding may not be possible in severe cases. In actual production, it is particularly important to control the reasonable tensile coefficient to ensure the adhesion between the insulation and the conductor. The stretching balance DRB value should not be less than 1.0, otherwise there will be insulation loose sleeve phenomenon, especially in single-line extrusion, its value should be adjusted to 1.05~1.15, but the DRB value should not be greater than 1.2, otherwise it will be in the extrusion speed When the melting vertebral body rupture, affecting product quality. In general, the length of the thermoplastic fluoroplastic extrusion die is not more than 15mm. For the processing line diameter is larger, the draw ratio DDR between 5~10, the length of the line of the extrusion die should be increased to about 12mm, so as to increase the pressure of the molten resin in the die and reduce the fluctuation of the extrusion diameter, so as to achieve the purpose of stable extrusion.

3. Extrusion temperature

When extruding thermoplastic fluoroplastics, the temperature setting is proportional to the extruded wire diameter and speed. The larger the wire diameter, the higher the extruder screw speed, the higher the set temperature. In the extrusion process, the recycling fluoroplastic manufacturers judge whether the temperature is appropriate by observing the state of the fluoroplastic molten cone. If the temperature is too low, it will lead to the existence of internal stress in the insulation and cracking; excessive heating will lead to local decomposition of fluoroplastics, resulting in the existence of bubbles on the surface of cable insulation or sheath, seriously affecting product quality. At the same time, the wire core should be preheated before entering the head, and a heat preservation and heating cover should be added outside the mold and the molten cone to avoid temperature changes leading to viscosity changes of the molten cone, which will affect the extrusion speed and product quality.

4. Cooling control

Fluoroplastic is a crystalline organic polymer material, so it is not appropriate to use the cooling quenching method, due to the high extrusion temperature of fluoroplastic, so the temperature of the cooling medium should reach the best proportion of material crystal nucleus growth rate and grain growth rate. The insulation or sheath after extrusion shall be cooled by sectional cooling, I .e. the water temperature of the water tank shall be set from high to low, so as to avoid loose sleeve or internal stress in the extrudate caused by rapid cooling.

With the development of science and technology, coupled with the acceleration of urbanization in China, the increase of high-rise buildings, people's requirements for wire and cable fire prevention are also getting higher and higher, coupled with the limitation of space, the wire and cable diameter is required to be small and the current carrying capacity is large. Therefore, the fluorine plastic wire and cable with high thermal stability, high flame retardancy and low loss has been favored by the recycling fluorine plastic manufacturers, and its application field is also expanding. Therefore, the recycling of fluorine plastic manufacturers only for the factory equipment curing fluorine plastic line production process, pay attention to the above four aspects of production factors, reduce production costs, to ensure the quality of products, in order to obtain a place for special cables, open the broad prospects of fluorine plastic cables.

This article comes from:www.tflpfa.com

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