Fire resistance cable compound means cable material with flame retardant performance, and could pass Bundle cable combustion test.LSOH material is usually used in poorly ventilated areas such as power station, airport, railway station, nuclear power station that with high population density. Cable compound means insulation material for cable insulation and sheath, including rubber, plastics, and currently most common used is plastics cable material, such as flame retardant PE sheath compoung, ETFE sheath compound, EVA sheath compound, PVC sheath compound etc..
Flame retardant compound must meet below requirement: the material itself has fire resistance performance; it can maintain good mechanical property, processing property; it has low smoke release and low toxity. Currently common used thermoplastic resin including PE, PVC, PP, EPR,EVA etc..
The price of PVC is relatively cheap, and the content of chlorine is 56%, so it has better heat resistance, electrical insulation performance. But PVC will release toxic and corrosive gases such as HCl, Chloromethane etc., so PVC is prohibitated in some country.
PE has higher volume resistance, dielectric strength, low dielectric loss, and it is getting more and more attention. China start manufacturing of PE cable compound in 1980s, and mainly used in communication. But PE is nonpolar material, it has bad compatibility with halogen free flame retardant, and PE itself doesn’t have good flame retardant performance, so it needs high filling of flame retardant to achieve better flame retardant performance, but will decrease the mechanical performance of system.
EVA has good optical property, flexibility, ESCR, low temperature resistance performance and has better compatibility with inorganic flame retardant, which could uniformly disperse inorganic flame retardant among it, and improve the comprehensive perofrmance of compounding material, especially mechanical property. So EVA becomes the first choice for HFFR polyolefin cable compound. But EVA also has disadvantages, like many high polymer, EVA is flammable, and will release toxic gas during combustion, so it is important to fabricate EVA with flame retardant and smoke suppression performance.
And magnesium hydroxide and aluminum hydroxide is the most commonly used inorganic flame retardant in EVA HFFR Cable compound formula. Feel free to comment down below if you have any question, Thank you for your time.