Can a halogen-free flame retardant system be selected when making PP flame-retardant plates?

The production process of general PP plates includes: feeding; extrusion, using a single - screw extruder to extrude the material barrel; heating in four zones; evaporating the moisture contained in the PP raw material and timely discharging it through the exhaust holes set on the material barrel; and then extruding it into a mold to form and shape it into a plate. 

For halogen - free formulations, among the halogen - free additive - type flame retardants for flame - retardant PP, intumescent flame retardants are commonly used. When each component in the intumescent flame retardant is used alone, the flame - retardant efficiency for PP is not good. However, when they are used together, the flame retardancy of PP is significantly improved due to the increase in char yield. Generally, the addition amount of the halogen - free flame - retardant system is relatively high. On the one hand, it is not easy to disperse with a single - screw extruder. On the other hand, too much addition will also affect other properties of the plate. 

Therefore, in order to achieve better dispersion and better flame - retardant effect, it is recommended to use flame - retardant masterbatches for PP plates.