Yuan Lei's Little Knowledge | Indicators of Talcum Powder in Plastic Application
As a plastic filler, talc can not only save the amount of resin used, but also significantly improve the rigidity, impact strength, creep resistance, hardness, surface scratch resistance, heat resistance and heat distortion temperature of the product. The index requirements of talc powder for plastics mainly include purity, whiteness, flake, fineness, SiO content, fluidity, static electricity, etc.
Purity:Purity refers to the content of talcum powder, nature and industrial production of talcum powder will contain impurities. The higher the purity, the better the enhancement effect. If the content of carbonate, iron, heavy metal and other impurities in talc is high, the aging resistance and thermal stability of plastic products will be poor.
Whiteness:Although the level of whiteness has no effect on the physical properties of the product, it is very important for light-colored products to maintain the purity of the color. One disadvantage of talc is that the color of the plastic is more or less darkened after mixing, which is an important factor limiting the widespread use of talc in plastics.
Degree of flake:The remarkable strengthening effect of talc on molecular compound plastic products mainly comes from its peculiar micro-sheet structure. The more complete the flake structure of talcum powder, the more obvious the strengthening effect. The two main factors that affect the flake of the product are: talc purity, powder processing essentials and skills.
Fineness:Generally speaking, the finer the better, which is also a major application trend of talcum powder. The higher the fineness of the talc, the better the reinforcing effect. But there is no need to blindly pursue only fineness. At the same time, the particle size distribution of talc powder should be controlled, the more uniform the better, so as to avoid too many coarse particles affecting the effect.
SiO₂ content:Silicon (SiO2) content in talc powder is an important index to measure the grade of talc powder. According to the performance requirements of different plastic products to choose talcum powder, the film added talcum powder silicon content is higher, the particle size is small, the particle size distribution is narrow, in order to make the index has obvious improvement. In the injection molding, plate, bar silicon content requirements do not have to be too high, low silicon content of talcum powder price is low, while rich in resources.
Liquidity:In the extrusion process, talc has poorer fluidity than other granular inorganic materials, is difficult to disperse, and has a large screw torque. Therefore, the use of better activation additives is the key to overcome the above problems.
Electrostatic:Talc is easy to produce static electricity, because talc is a layered structure, large specific surface area, irregular particle shape and surface convex and concave shape make its coefficient of friction large, resulting in small particles between the cohesion, difficult to disperse, affecting the use effect. Static storage can be used to eliminate static electricity, which is both practical and easy to operate.
Plastic, talcum powder, talc, content, effect, better, influence, purity, static electricity
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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.