What are the differences in the effectiveness and applications of using talcum powder and calcium carbonate as fillers?

Adding talc and heavy calcium carbonate as fillers can appropriately increase the dimensional stability of the product (i.e., reduce shrinkage), enhance the material's rigidity, improve its heat resistance, and lower production costs. However, as the product's density increases, improper use can lead to a decrease in impact toughness and a reduction in the luster of some products. The main differences between talc and calcium carbonate are as follows: talc, with its flake-like ore structure, offers higher rigidity, dimensional stability, and heat resistance, with slightly better performance. Calcium carbonate is generally granular, so it is not as good as talc in terms of rigidity and other aspects, but it is more affordable and has a higher whiteness than talc, with less impact on plastic toughness. Additionally, talc products have a nucleating effect on polypropylene, while calcium carbonate does not exhibit such effects.