Can fillers be added to the flame - retardant corrugated pipe? Will the flame - retardant performance be affected?

Fillers can be added to the flame-retardant corrugated pipes. Commonly, the fillers added to corrugated pipes include calcium carbonate, talcum powder, kaolin, attapulgite clay, etc. 

These fillers are inexpensive and easy to process, and have become the choice of many corrugated pipe manufacturers. 

Talcum powder has a flaky structure, excellent mechanical properties and stable processability. In particular, it is suitable for thin products in PP fireproof corrugated pipes, and its characteristics are particularly prominent. The whiteness of talcum powder is slightly lower than that of calcium carbonate, generally between 86% and 90%. Talcum powder is easy to absorb moisture and is not suitable for long-term storage. 

The most commonly used filler in the masterbatch is 400-mesh heavy calcium carbonate. Generally, the required whiteness is above 95%, the water content is less than 0.3%, and the heavy metal content is less than 0.3%. The contents of iron and silicon have a great influence on the product. When the iron content is high, it affects the whiteness of the product, and silicon will also cause serious wear to the processing equipment. 

However, when adding calcium carbonate, it should be noted that calcium carbonate will affect the flame-retardant effect. Generally, we recommend adding less of it or replacing it with other filler materials.