For a long time, wires and cables with PVC as the base material or with halogens such as deca bromine as the main flame retardant almost monopolized the main market of wires and cables. However, when halogen-containing substances are burned, HCI or other toxic corrosive gases are released. These toxic gases and thick smoke not only endanger human life, but also seriously corrode instruments and other facilities, which puts forward new requirements for the safety of wires and cables. The global awareness of environmental protection centered on Europe is increasing day by day, and various countries' restrictions on substances affecting the environment have also begun to gradually strengthen. For example, the Organisation for Economic Co-operation and Development in Europe (OECD) has launched a call for significant reductions in lead and certain brominated flame retardants. In the European Waste Electrical and Electronic Equipment (WEEE) recycling law, the use of brominated flame retardants is particularly restricted. In Japan, various government offices and local public agencies have required the use of environmentally friendly wires that do not contain halogens and lead when building new government office buildings.
Low smoke zero halogen cable material technology
Low smoke zero halogen flame retardant polyolefin cable material is usually composed of polyolefin blend resin plus flame retardant filler aluminum hydroxide, magnesium hydroxide and some appropriate amount of antioxidant added to improve heat resistance life. Sometimes in order to reduce the amount of smoke generated during combustion, some smoke inhibitors are added, such as vanadium, nickel, molybdenum, iron, silicon, nitrogen compounds. Its flame retardant mechanism is: when burning, the flame retardant fillers aluminum hydroxide and magnesium hydroxide will release crystal water and absorb a lot of heat. At the same time, the dehydration reaction produces a large amount of water vapor, which can dilute the flammable gas and prevent combustion. In addition, a layer of infusible and incombustible oxide hard shell will be formed on the surface of the material, which blocks the channel for the reaction between the polymer and the external thermal oxygen, and finally the material is flame-retardant and self-extinguishing.
Low smoke zero halogen flame-retardant polyolefin cable material should have good flame retardancy, and aluminum hydroxide and magnesium hydroxide in the formula must have a large filling amount, usually more than 150 parts. However, a large amount of inorganic flame retardant filling will inevitably lead to great deterioration of the material in terms of physical and mechanical properties, electrical properties and extrusion process properties. In order to solve the balance of its flame retardancy and physical and mechanical properties, the material can fully meet the technical requirements of final use. The commonly used methods are: on the one hand, the polyolefin material is modified to improve the polarity of the polyolefin material. Another aspect is the chemical modification of the surface of the inorganic flame retardant, usually treated with a coupling agent.
The characteristics of low smoke zero halogen cables
The use of a large number of inorganic flame retardants endows the Low smoke zero halogen flame-retardant polyolefin cable material with flame-retardant, low-smoke, halogen-free, and low-toxicity properties. At the same time, it is also different from other non-flame retardant and halogen-containing flame retardant materials in terms of physical and mechanical properties, electrical properties and extrusion process properties.
Due to the different production processes of Low smoke zero halogen wires and cables and their supporting products, the performance requirements are also different, such as tensile strength, elongation at break, aging temperature and indicators, volume resistivity, oil resistance, scratch resistance , flexibility, flame retardant requirements and so on. Different cables tend to be biased. In the halogen-free material technology, some of the above indicators are mutually restrictive, and it is impossible to have an all-round product that can meet the requirements of all the above types of wires and cables. The more prominent contradictions are the contradiction between elongation at break and flame retardancy, and the contradiction between softness and thermal deformation and aging properties.
Low smoke zero halogen cable factory
Shenghua Cable Co., Ltd., an excellent low smoke zero halogen cable manufacturer, sells all kinds of high-quality low smoke zero halogen cables. If you want to know more about cables, or are interested in our products, you can visit the website of Shenghua Cable Co., Ltd. to contact us.