With the rapid development of the economy, the demand for wire and cable materials is increasing rapidly, and with the requirements of safety and environmental protection, new requirements for wire and cable materials are also put forward. The introduction of plastic modification technology to the application of wire and cable materials can not only meet the requirements of safety and environmental protection but also reduce the production costs of various enterprises.

Polyvinyl chloride (PVC) wire and cable material

The base resins for the production of cable materials are mainly PVC, polyethylene (PE), and polypropylene (PP). Among them, PVC is the largest. PVC resin has the characteristics of flame resistance, oil resistance, chemical corrosion resistance, water resistance, etc., and has the advantages of good physical and mechanical properties, excellent electrical properties, etc., making it an ideal coating material for the wire and cable industry. However, PVC material has poor temperature resistance, weather resistance, and wear resistance, and the precipitation of plasticizer during use makes the aging performance of the material deteriorate, which makes PVC material difficult to adapt to the current environmental protection requirements and also difficult to adapt to the requirements of some special cables. In addition, the biggest drawback of PVC as a cable material is that it will release a lot of smoke and toxic and corrosive hydrogen chloride (HCl) gas during the combustion process. Therefore, the modification of PVC to improve its overall performance is the primary problem facing the current.

Main methods of modification methods for PVC

(1) The application of non-toxic PVC heat stabilizer

Calcium/zinc composite stabilizer is an important variety of non-toxic PVC heat stabilizer. In recent years, it has also been one of the most active fields in the research and development of composite stabilizers. Its research direction is to continuously improve its thermal stability and give more functionality through the combination of various auxiliary stabilizers, so that it can be used in wire and cable and other fields. Heat resistance has been greatly improved, and it can also replace or partially replace lead and cadmium stabilizers to develop new PVC products. Rare earth heat stabilizer is one of the most concerned non-toxic PVC heat stabilizers in recent years. Studies have shown that rare earth elements have the ability to form coordination complexes and can absorb a large amount of HCl produced by PVC degradation during PVC processing, thus playing a stabilizing role.

(2) The application of PVC irradiation crosslinking technology

Irradiation crosslinking techniques mainly include CO60-gamma rays, high-energy electron rays, ultraviolet radiation crosslinking, and chemical crosslinking. Compared with chemical crosslinking, radiation crosslinking has the characteristics of a simple process, low energy consumption, high yield, and no pollution, and has a wide application prospect. In recent years, the research on the radiation crosslinking of PVC has attracted much attention, which can realize the gradual control of the structure and properties of radiation crosslinking PVC products.

(3) The application of PVC flame retardant smoke suppression technology

Although PVC itself has better flame retardant properties, the process of processing and molding requires adding a large number of plasticizers, which is bound to make the flame retardant performance of PVC significantly reduced; therefore, it must be a flame retardant smoke suppression modification. Flame retardant and smoke suppressant modification has the advantages of a simple process, many kinds of flame retardant and smoke suppressant, and low cost, so it has been widely concerned and applied. The main types are inorganic flame retardant smoke suppressors, nanoflame retardant smoke suppressors, and organic flame retardant smoke suppressors. In a variety of cable products, in addition to steel core aluminum stranded wire, electromagnetic wire, and other bare wire products, almost all other wires need to have an insulation layer, a sheath layer, a shielding layer, and so on to protect, so a lot of modified plastics need to be used. With the improvement of China's economic strength and the further promotion of modernization, it is expected that the demand for modified plastics for cable products in China will increase at a rate of 10% in recent years. Although the consumption of PVC cable material is very huge, as people's requirements for safety and environmental protection are getting higher and higher, the application of PVC materials on cables will be greatly restricted. In recent years, low-smoke halogen-free cable material has been the key product that major manufacturers compete to develop.