The Role of Mica In Plastics
Jan. 26, 2021
1.Physical and mechanical properties
The Mica with a two-dimensional flake structure plays a role of plane reinforcement in the plastic and improves the bending elastic modulus and tensile strength of the product. The physical and mechanical properties of mica reinforced plastics are between those reinforced with glass fiber and mineral fillers. Compared with glass fiber reinforced plastics, the advantages of mica reinforced plastics are higher modulus and lower warpage.
The uniform orientation of mica in the plastic ensures the anisotropy of the product, prevents warping and deformation, and can also give the product excellent dimensional stability. Mica is a mineral filler that has the most obvious impact on the shrinkage of PP and PA modified materials, which can significantly reduce the molding shrinkage of products.
Mica Powder has good thermal stability. It can prevent the production of volatiles during the thermal decomposition of the plastic while insulating, and improve the thermal stability of the material.
The addition of mica powder contributes a lot to improving the damping performance of the product. Under the combined action of the volume effect and friction effect of the flake filler, the energy loss of the material is large, and the damping value is large.
4.UV shielding performance
Mica is a natural mineral filler with excellent UV shielding performance and mechanical enhancement effect. The UV shielding effect in some application systems can completely replace organic UV absorbers, greatly reducing manufacturing costs.
Mica has extremely high electrical resistance and is a high-performance insulating material. In the field of electrical communication in the field of low-voltage electrical appliances, mica filling is an ideal choice. If you need to make highly insulating plastic products, you can consider adding functional filler wet mica powder, but mica with high iron content has lower insulation properties and should be avoided.
In the plastic processing process, through the rolling and stretching of the material, the Mica Wafers can form a parallel orientation arrangement in the plastic. The orientation is parallel to the surface of the plastic product and perpendicular to the permeation and escape direction of gas and liquid. Layers of barriers are formed in such materials, making it extremely difficult for gas and liquid to penetrate. When gas and liquid penetrate the plastic, they must constantly bypass and surpass the mica wafer. The penetration path is extremely tortuous. Therefore, the mica-filled plastic has excellent gas and liquid barrier properties. However, to obtain excellent barrier effect, the diameter-to-thickness ratio of the flake filler must be at least 50 times, preferably more than 70 times. The diameter-thickness ratio of wet-process mica powder is as high as 80-120 times, and can be used in plastic materials that require high barrier properties.