Low smoke halogen-free granulator | Low smoke halogen-free cable material granulator | Cable material granulator

Low smoke halogen-free granulator
Low smoke halogen-free cable material granulator
Low smoke halogen-free flame retardant polyolefin cable material is usually made of polyolefin blend resin plus flame retardant filler aluminum hydroxide It is composed of magnesium oxide and some appropriate amounts of antioxidants added to improve heat resistance life. Sometimes in order to reduce the amount of smoke produced when burning, some smoke inhibitors are added, such as vanadium nickel molybdenum iron silicon nitrogen compounds. Its flame retardant mechanism is that when burning, the flame retardant filler aluminum hydroxide and magnesium hydroxide will release crystal water and absorb a large amount of heat. At the same time, the dehydration reaction will generate a large amount of water vapor, which can dilute the flammable gas and prevent combustion. In addition, a layer of non-melting and non-combustible oxide hard shell will be formed on the surface of the material, blocking the channel for the polymer to react with external hot oxygen. Ultimately, the material will be flame retardant and self-extinguishing.
Low-smoke halogen-free flame-retardant polyolefin cable materials must have good flame retardancy. The aluminum hydroxide and magnesium hydroxide in the formula must have a large filling amount, usually more than 100%, and an internal mixer is required. The materials are better compatible with inorganic substances. After the materials are mixed, single-screw cooling and granulation equipment is used to make materials, disperse the output, and improve energy consumption. Single-screw hydraulic automatic screen changer Air-cooled grinding surface hot cutting First cyclone separator Second cyclone separator Extended air-cooled vibrating screen Bin Welcome to inquire Research on halogen flame retardant
Table 3 High expansion and low expansion graphite pairs The influence of limiting oxygen index
The content of expanded graphite
It can be seen from Table 3 that with the increase in the amount of expanded graphite, the oxygen index of It is more effective because at high temperatures, the volume of the expanded graphite generated is larger than that of the product. It occupies a larger space and is more conducive to preventing the combustible gas generated by polymer cracking from entering the combustion area and more effectively isolating the expansion of oxygen. The function of graphite is a physical mechanism, mainly the dense carbon layer forming a physical isolation layer, protecting the polymer under the carbon layer, and isolating heat and mass transfer. The latest research methods of halogen flame-retardant polyolefin materials
In recent years, with the advent of cone calorimeters, the application and evaluation of flame-retardant materials have also been carried out in depth. Cone calorimeter was proposed by the National Institute of Science and Technology in 2001. It is a new generation of polymer combustion measuring instrument based on oxygen consumption. Compared with traditional laboratory evaluation methods such as oxygen index, cone calorimeter There is a good correlation between the instrument and the results of large-scale combustion experiments. It can simultaneously provide the heat release rate, total released heat, effective combustion heat, extinction area during ignition, soot yield, mass loss rate, etc. Combining with can study whether the flame retardant is a gas phase mechanism or a condensed phase mechanism for polymer flame retardancy. Combining infrared photoelectron spectroscopy and thermogravimetric analysis can further explore the chemical phenomena of the combustion process of the combination of flame retardants and polyolefins, thereby analyzing the flame retardant mechanism and providing a theoretical basis for the next step in the development of new flame retardant systems. France systematically studied the influence of the chemical structure and characteristics of the carbonized layer on the flame retardant effect.
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