Application of talcum powder
Application in coatings
Talc has good suspension and dispersibility, and low corrosiveness. In coatings, talc as a filler can act as a skeleton, reducing manufacturing costs and increasing the hardness of the paint film. It also has the characteristics of improving the stability of the product shape, increasing the tensile strength, shear strength, pressure strength, reducing deformation, elongation, thermal expansion coefficient, high whiteness, and strong uniform particle size dispersion. The talc powder with the flaky particle structure can make the coating film have high water resistance and impermeability of the enamel. The talc powder with the fibrous particle structure can improve the rheology and leveling properties of the coating. Weather resistance of the coating.
Talc is mainly used in primers and intermediate coatings. Many products, flash baking primers and paints for transportation vehicles are preferred to use talc. The primer for steel structure can use talc powder in whole or in part to improve the precipitation of the coating, the mechanical force of the coating film and the recoatability.
Application in plastics
Inorganic fillers play an important role in plastic modification and become an indispensable modifier. The white talcum powder with flake structure is an effective reinforcing material in plastics. It can endow plastics with higher rigidity, creep resistance and better solid gloss regardless of normal temperature and high temperature. The addition of talc can change various properties of plastics, such as molding shrinkage, surface hardness, flexural modulus, tensile strength, impact strength, thermal deformation temperature, molding process and product dimensional stability. Adding talc powder to polyethylene and polypropylene plastics can effectively improve the surface hardness and surface scratch resistance of the products. It is well known that the price of talcum powder is 10%-20% of plastics, so the application of talcum powder to plastics not only improves performance, but also effectively reduces the cost of materials and improves the economic benefits of enterprises.
Application in papermaking
Talc has unique properties such as layered structure, softness, and hydrophobicity. It has significant advantages when applied to the paper industry: (1) It helps to increase the retention of fillers and improve the opacity, smoothness and printability of paper. It gives the paper high ink absorption; (2) It is chemically stable, not only suitable for papermaking under acidic conditions, but also can be used with calcium carbonate for papermaking under neutral conditions; (3) Its surface is hydrophobic Lipophilicity, organic matter is easily adsorbed on its layered surface. The addition of talc reduces the consumption of dyes and effectively saves costs. In addition, the lipophilicity makes it useful as resin, adhesive inhibitor and waste Paper deinking agent; (4) It can be combined with sizing agent to improve the retention of sizing agent, and can reduce the absorption of the paper and prevent the printing ink from penetrating the paper; (5) Talc has a lower friction factor , It can make the coating surface smooth and soft, can reduce the breakage of the coating, reduce the printing pressure, etc.; (6) As a coating pigment with high aspect ratio, talc has excellent fiber coverage and good printing effect. It can improve the quality of gravure printing; (7) Talc has special lubricity, and the coated paper made from it can obtain high finishing degree on the calender, and can reduce the amount of lubricant in the coating.
Food application
Edible talcum powder is used as an additive in the medicine and food industries. It has the characteristics of non-toxic, tasteless, soft taste and strong smoothness, so it can be eaten, but excessive use or long-term consumption can cause cancer.
According to the national standard GB2760-2011, the maximum use amount of talcum powder in jasmine fruit and huahua (licorice products) is 20.0g/kg.