What are the main problems currently existing in the production process of PVC low smoke zero halogen cable?

What are the main problems currently existing in the production process of PVC low smoke zero halogen cable?

The main cause of these problems is that the flame retardants used in the low smoke and halogen-free material formula are mainly magnesium hydroxide or aluminum hydroxide. However, the flame retardant efficiency of magnesium hydroxide or aluminum hydroxide is not high. To achieve the flame retardant effect, the usual dosage in the formula is relatively large. During the material molding process, the fluidity is poor, the friction is large, and the generated frictional heat is much. The higher the extrusion speed, the greater the frictional heat, the faster the temperature rises, and only low-speed extrusion can be adopted. During the molding process, magnesium hydroxide or aluminum hydroxide is prone to sticking to the mold, resulting in poor surface smoothness of the cable. In addition, magnesium hydroxide or aluminum hydroxide also has a hygroscopic effect, and at high temperatures, it is easy to decompose and release moisture, which easily causes the appearance of pores or bubbles on the surface of the cable during molding, resulting in poor surface smoothness.