Yuan Lei's Little Knowledge | Application of Talcum Powder in Plastic Industry
Talcum powder is used in plastics as a filler for plastics such as polypropylene, nylon, polyvinyl chloride, polyethylene, polystyrene and polyester. It can increase the stability of the product shape, increase the tensile strength, shear strength, winding strength, pressure strength, reduce deformation, elongation, thermal expansion coefficient, high whiteness, uniform particle size and strong dispersion.
The nine elements of plastic choice talcum powder
1. High purity
The higher the purity of the talc, the better the reinforcing effect. Other mineral impurities in talc, metal minerals have a very significant impact on the aging resistance of plastics.
When high-quality ultra-fine talcum powder is used in plastic products, it can be evenly dispersed in the resin in a laminated form. It has good compatibility with the resin and complementarity of mechanical properties. It can maintain the advantages of the plastic and form a reinforced support form with excellent mechanical properties. It can improve the physical properties of plastic products and has obvious heat preservation and barrier effects. It can reduce production costs at the same time, can improve the physical properties of plastic products.
3. Wet whiteness and hue
After the talc powder and the plastic are mixed, the color of the plastic changes more or less. Dark plastic products do not have too high requirements for the whiteness of the added talc. However, in order to make light-colored products have better colors, talcum powder should have higher wet whiteness and suitable hue.
4. Silica content
Silicon in Talc (SiO2) Content is an important indicator to measure the grade of talc powder. The higher the silicon content in talc powder, the higher the purity of talc, the better the application effect, and the higher the price.
The colors of raw talcum powder ore are different from each other, and can be white, gray, light red, pink, light blue, light green and other colors.
6. Surface properties
Talcum powder exhibits different surface properties depending on its source. The specific surface area and oil absorption rate are largely determined by mineral resources and product fineness.
Talcum powder structure determines its characteristics, talcum powder is hydrophobic, but because of the irregularity of the particle shape edge, both structural water and crystal water, so the water content of talcum powder is larger than that of calcium carbonate, and the water content can easily affect the performance of plastic, so the water removal of talcum powder and the drying process should be paid great attention.
Talcum powder has a layered structure and a large specific surface area. The irregularity of particle shape and the convex and concave shape of the surface make its friction factor large and easy to generate static electricity, which makes it difficult to disperse the cohesion between tiny particles and affects the application effect.
In the extrusion process, the flake structure of talcum powder has poor fluidity than other granular inorganic materials, is difficult to disperse, and the main screw torque is large, so better activation coating is the key to overcome these problems.
Application of Polypropylene Resin
Talcum powder is commonly used to fill polypropylene. Talcum powder has a flake-like structure characteristic of a flake configuration. Therefore, talcum powder with fine particle size can be used as a reinforcing filler for polypropylene. In the modified system of polypropylene, the addition of ultrafine talc can not only significantly improve the rigidity, surface hardness, heat creep resistance, electrical insulation, dimensional stability of polypropylene products, but also improve the impact strength of polypropylene.
Application of ABS resin
The superfine talc powder masterbatch manufactured by special method has good dispersion and uniformity when added to the plastic. ABS resin is an amorphous polymer with excellent molding processability like polystyrene; it has good impact strength, good low temperature resistance, high tensile strength, good creep resistance, and can withstand 7Mpa load without changing the size. The addition of superfine talc masterbatch can not only significantly improve the original performance of ABS, but also reduce the cost.
Application of Polystyrene Resin
Unmodified general-purpose polystyrene is an amorphous polymer. It is hard and brittle, but it has good electrical properties, aging resistance and high dimensional stability. The disadvantage is high brittleness and sensitivity to environmental stress cracking. The addition of superfine talcum powder can improve the impact toughness, adjust the rheology, the disturbance modulus is significantly improved, and the tensile yield strength is also improved.
Application in Nylon Resin
For nylon (polyamide), special attention is paid in the industry to take advantage of the toughness and abrasion resistance of this plastic. Nylon is generally hard, similar to horny, with good abrasion resistance and high dimensional stability. These properties can be further enhanced by fillers or reinforcing agents.
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The difference between barium sulfate（BaSO4） and barium sulfite（BaSO3）
Kaolin is a non-metallic mineral, which is a kind of clay and clay rock mainly composed of kaolinite clay minerals. Because it is white and delicate, also known as white earth. It is named after Gaoling Village, Jingdezhen, Jiangxi Province.