How to choose fillers or additives for flame-retardant PP of different flame-retardant systems?

Which filler should be selected for flame-retardant PP of different flame-retardant systems?

In the PP resin + bromine + antimony + co-marketing flame retardant system, calcium carbonate has a certain effect on flame retardancy, and the more talc and barium sulfate are added, the better the flame retardancy;

In the PP resin+expanded carbon system, in principle, no fillers can be added. The addition of fillers will destroy the lethality of the carbon layer produced when carbon is formed, and will have a greater impact on the flame retardancy;

In the PP resin + new carbon forming system, a certain proportion of glass fiber or wollastonite can be added. It is not recommended to add other fillers;

In the case of PP resin + high-efficiency flame retardant system, the industry generally believes that high filling and calcium carbonate have a greater impact on flame retardancy. After the author's research, to overcome this technical difficulty, a better flame retardant effect can be achieved even with the addition of 50% calcium carbonate.

What are the effects of other additives such as pigments, black masterbatch, oils, etc. on flame-retardant PP of different flame-retardant systems?

Experiments have proved that no matter what system it has, it has a certain effect on flame retardancy. In the PP resin + expanded carbon flame retardant system, carbon black has the greatest impact on flame retardancy. Therefore, the production of black halogen-free flame-retardant PP has greater difficulty.

When using high-efficiency flame retardants, oils and titanium dioxide have a greater impact on the flame retardant system.

Therefore, the principle of simplicity must be followed when producing flame-retardant polypropylene. Do not add as much as possible, and add as little as possible.