At present, about 75% of the domestic heavy calcium carbonate products are powders of less than 400 mesh, which is difficult to meet the application requirements of some plastic products with high mechanical properties such as bending strength and impact strength, such as PVC profiled materials, automotive plastic parts, engineering plastics, PVC film, packaging film, mulching film, incinerable garbage bags, etc. These applications generally require high purity, fine particle size and surface modification. The average particle size of HDPE film is less than 1 μ m, and the modified heavy calcium carbonate filling masterbatch with average particle size of 1-4 μ m is required for polyolefin and PVC thermoplastic composites.

It can be seen from the above table that the proportion of heavy calcium carbonate products used in agriculture, packaging, construction and other fields is not very high. At present, the proportion of agricultural plastics used in China is still very low, while the amount of agricultural degradable plastic film used in developed countries is more than 30%. At present, there are some problems in the use of heavy calcium carbonate: first, the addition is relatively low. Due to the lack of fineness of powder, the addition ratio of most products is not high, especially in the film grade products with higher requirements; second, the application range is not large enough, and most products still refuse to use fillers due to some traditional concepts. Because pure plastic products are difficult to degrade and burn, it is not conducive to environmental protection. If more than 30% of heavy calcium carbonate is added, it will help to degrade itself or burn it thoroughly, or protect the incinerator and the environment. When using 30% heavy calcium carbonate, the film can still maintain high tensile depth and tear strength, which can reach the effect of similar products in Japan, and keep the appearance smooth and delicate.