Effect of aluminium hydroxide addition on the performance of cable compounds

In order to achieve the flame retardant requirements of low smoke halogen-free wire and cable, it is necessary to add about 50% or more aluminum hydroxide in the formula, aluminum hydroxide powder is less than 2um particle size of the powder, polymer is generally 2-3mm particles, the size difference between the two is large, and are inorganic and organic, so in the mixing process to ensure the uniformity of material mixing will directly affect the mechanical and flame retardant properties of wire and cable particles. The mixing process will therefore have a direct impact on the mechanical and flame retardant properties of the wire and cable granules. With the increase in the amount of aluminium hydroxide added, the increasing mixing torque makes it more difficult to mix evenly, the wire and cable fracture elongation is gradually reduced, the melt flow rate is reduced, but the oxygen index increases due to the increase in aluminium hydroxide content. Such as in the raw material mixing process because of the short mixing time or high viscosity of the material is difficult to mix, wire and cable particles in the material changes in the composition of the product will lead to mechanical or flame retardant performance failure, the emergence of unqualified products. Therefore, whether the mixing process can ensure that the material is mixed evenly will affect the performance of the wire and cable pellets.