There are more than a thousand talc production and processing enterprises in China, but no more than 10 enterprises can produce fully qualified molecular compounds for plastics. There are no more than 15 companies that can produce basic qualified products. At present, China's relatively capable manufacturing enterprises focus on the production of export products and seriously ignore the growing domestic demand. A large part of the talc used in the domestic molecular compound plastics industry comes from SMEs and informal enterprises. This makes it difficult to guarantee product quality. At the same time, it is worth mentioning that the origin of some talcum powder used in scientific research in China is also very uncertain, which makes the reliability of its conclusions greatly reduced.

Talc has a significant strengthening effect on molecular compound plastics, but not all talc products have a strengthening effect. The enhancement effect is very different with different product grades. It is difficult to propose uniform and specific standards for talc used in the molecular compound plastics industry. The general principle is: try to use pure talc products with the appropriate particle size, the product does not have to be as fine as possible. In view of the diversity of talc mines, achieving technical results requires technical support from manufacturers. When selecting a product, at least the "four degrees" of talc should be considered, that is, purity, whiteness, fineness, and flake.

I. Purity

Purity refers to the talc content of the product. Talc is contained in nature and in industrial production, and 100% pure talc products in the industry cannot exist. There is no doubt that the higher the purity of talc, the better its strengthening effect. Studies have shown that certain impurities in talc not only reduce the purity, but also have a significant effect on the performance of the final product.

Second, whiteness

There are two types of whiteness in the talc test: narrow and broad. Narrowness of whiteness is the general definition of whiteness, which can be expressed by blue light whiteness, Ganz plastic characteristic whiteness, Hunter whiteness, and so on. There are no less than a hundred formulas for calculating whiteness in the world, and no less than 10 formulas often used in the non-metallic mining industry. Broad whiteness includes dry whiteness, wet whiteness, and hue. For the same raw material, the finer the particle size, the higher the whiteness. The higher the moisture, the lower the whiteness. Although the degree of whiteness has little effect on the physical properties of the product, it is very important to maintain the purity of the color for light-colored products.

Third, the degree

The significant strengthening effect of talc on molecular compound plastic products mainly comes from its peculiar micro-flaky structure. The more complete the talc powder-like structure, the more obvious its strengthening effect. The two main factors that affect the flaky shape of the product are: talc purity and powder processing methods and skills.

Fourth, fineness

Micronization is the development trend of talc products. The finer the product, the better the strengthening effect, but at the same time the surface energy of the particles increases, it is easy to agglomerate, separation is difficult, and the price is high. Therefore, it is necessary to select products with appropriate fineness according to their own skill level and actual needs. It is not necessary to be as fine as possible.

Generally speaking, to evaluate the advantages and disadvantages of a talc product, at least the above four aspects must be considered. Judging quality with only one indicator is one-sided and incomplete. If someone only judges the quality of talc products based on the average particle size, this is very questionable.