The role of talc powder in plastic modification

Application in nylon resin (PA)

For nylon (polyamide), the industry pays special attention to the toughness and wear resistance of this plastic. Nylon is generally hard, similar to keratin, with good abrasion resistance and high dimensional stability. These properties can be further improved by fillers or reinforcing agents.

The hardness, stiffness, abrasion resistance and heat distortion temperature of PA66 are the highest among nylons; PA6 is known for its higher toughness; PA610 has lower water absorption and thus higher dimensional stability; PA11 impact strength is higher than nylon The highest in it.

Among various fillers, the layered talc powder can improve the original good performance of nylon and improve the wear resistance. Compared with metal, unfilled modified nylon has low modulus of elasticity, low tensile and creep strength, and its mechanical properties are obviously dependent on temperature. The molecule contains water-absorbent gene amine groups, and the water absorption rate is high. The product is easy to absorb water during use. Expansion deformation, rapid cooling and incomplete crystallization during processing and molding, and incomplete crystallization during use, which leads to product deformation and even cracking.

The above shortcomings of nylon can be greatly improved by adding ultra-fine talc powder. Talc powder acts as a nucleating agent. After addition, it can increase the crystallization rate of nylon and increase the crystallinity, so it can especially improve the toughness and mechanical Strength, hardness, thermal stability, dimensional stability, improve the surface quality and deformation behavior of products, also have a good effect on moisture absorption, electrical properties and chemical properties.

Application in polypropylene resin (PP)

Talcum powder is often used to fill polypropylene. Talcum powder has the characteristics of flake-like structure. Therefore, talc powder with finer particle size can be used as a reinforcing filler for polypropylene.
In the modification system of polypropylene, adding ultra-fine talc powder can not only significantly improve the rigidity, surface hardness, thermal creep resistance, electrical insulation, and dimensional stability of polypropylene products, but also increase the impact strength of polypropylene.

Adding a small amount of talc powder to polypropylene can also act as a nucleating agent to improve the crystallinity of polypropylene, thereby improving the mechanical properties of polypropylene. Also, it can improve the crystallinity and refine the crystal grains. The transparency of polypropylene.

Polypropylene composites filled with 20% and 40% ultra-fine talc powder can significantly improve the rigidity of polypropylene and the creep resistance at high temperatures, no matter at room temperature or high temperature.
In the automobile industry, polypropylene with talc powder is mainly used in automobile bumpers and dashboards, and also used in fan covers, heater covers, ducts, battery heat shields, fluid pump parts, etc.; in the aircraft industry, Used in refrigerator door liners, heaters and vacuum pump covers, washing machine mixers; in the electrical industry, used for injection molding of various instrument shells and electrical components, in the home appliance industry, used for refrigerator drawers, washing machine drums and other injection molded parts .

Application in polyethylene resin (PE)
Talc is a natural magnesium silicate. It has a unique micro-scale structure, a certain degree of water resistance and a high degree of chemical inertness, so it has good chemical resistance and sliding properties.
Filled with polyethylene can be used as engineering plastics, with good chemical resistance and fluidity, and can compete with ABS, nylon and polycarbonate.

Filling polyethylene with it can improve the following properties: toughness, flexural modulus and twisting modulus; increase flexural strength; reduce creep tendency at room temperature and high temperature; increase thermal deformation temperature and dimensional stability; improve deformation and Warpage, while also having a lower coefficient of thermal expansion; improve thermal conductivity; improve the surface hardness and smoothness of molded parts; improve the mechanical strength of polyethylene.

Adding different proportions of talcum powder will have different effects on the physical properties of polyethylene materials, and the proportion of addition is 10%-15% to achieve the best.

For polyethylene blown film, the superfine talcum powder masterbatch is better than other fillers, and it is easy to form and has good manufacturability. Moreover, this kind of film can reduce the oxygen transmission rate by 80%, and is particularly suitable for packaging oily foods, such as peanuts, broad beans, etc., without oil or deterioration for a long time: this kind of film can reduce the water vapor transmission rate by 70% , Has good moisture resistance, very suitable for underground geotextile moisture-proof cloth, also suitable for packaging food.


Application in ABS resin
ABS resin is an amorphous polymer with excellent molding processability like polystyrene; it has good impact strength, good low temperature resistance, high tensile strength and good creep resistance.

In order to improve the existing performance of ABS, people have carried out extensive research on ABS modification. For example, the automobile instrument board blister sheet made by blending ABS and PVC, the imitation leather luggage cover made by blending ABS and PVC, not only has high strength and toughness, but also can maintain the durability of the surface pattern.

This blended material is filled with ultrafine calcium carbonate or ultrafine talc powder, which can significantly improve the notched impact strength and tear resistance of the blended material, such as adding ultrafine talcum powder or calcium carbonate 5%-15 %, the notched impact strength can be increased by 2-4 times.

Because ABS is an amorphous polymer, it has the function of accommodating more fillers. The addition of superfine talc powder can not only significantly improve the original performance of ABS, but also reduce the cost. Therefore, it is often used for injection molding of various instruments, televisions, radio cassettes, mobile phones, etc., and of course, it is also widely used in other fields such as textile equipment, electrical parts, auto parts, and aircraft parts.

Application in polystyrene resin (PS)

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 that it is brittle and sensitive to environmental stress cracking.

Adding ultra-fine talc powder can improve impact toughness, adjust rheology, significantly increase perturbation modulus, and increase tensile yield strength.

For example: adding 40% superfine talcum powder or talc powder masterbatch, the perturbation modulus increases from 23800kg/cm2 to 58800kg/cm2, and the tensile strength increases from 336kg/cm2 to 385kg/cm2.

Application in polyvinyl chloride resin (PVC)
Filling polyvinyl chloride with ordinary powder has been very commonly used. For example, in the manufacture of hard polyvinyl chloride pipes, the amount of calcium carbonate filled can reach 40%, but the tensile strength and impact strength of polyvinyl chloride should be reduced; if added evenly When the particles are 5 microns or 2000 mesh talc powder, when added to 40-45% by volume, it can be found that the yield strength of the material is even higher than the original breaking strength, which has a significant enhancement effect on the PVC system. For the impact strength, adding ultrafine talc, the unnotched impact strength is basically not reduced within 15% by weight, the notched impact strength is reduced, and the disturbance modulus can be significantly increased. Ultrafine powder has a very significant reinforcing effect on PVC systems with toughening agents, such as PVC/CPE and PVC/ABS systems.