Modification of calcium carbonate
Heavy calcium carbonate can increase the volume of plastic products, reduce costs, improve hardness and stiffness, reduce the shrinkage rate of plastic products, and improve dimensional stability; improve the processing performance of plastics, improve its heat resistance, improve the astigmatism of plastics, anti- At the same time, it has obvious effects on the toughening effect of notched impact strength and the viscous flow during the mixing process.
Calcium carbonate has been used as an inorganic filler in plastic filling for many years. In the past, calcium carbonate was generally used as a filler for the main purpose of reducing costs, and received good results. In recent years, with the extensive use in production and a large number of researches, it is also possible to fill a large amount of calcium carbonate without significantly reducing the production
After filling with calcium carbonate, due to the high hardness of calcium carbonate, the hardness and stiffness of plastic products will be improved, and the mechanical properties will be enhanced. The tensile strength and flexural strength of the product have been improved, and the elastic modulus of the plastic product has been significantly improved. Compared with FRP, its tensile strength, flexural strength and flexural modulus are roughly the same as those of FRP, and the thermal deformation temperature is generally Higher than FRP, the only thing inferior to FRP is its lower notched impact strength, but this disadvantage can be overcome by adding a small amount of short glass fibers.
For pipes, filling calcium carbonate can improve several of its indicators, such as tensile strength, steel ball indentation strength, notched impact strength, viscous flow, heat resistance, etc.; but at the same time it will reduce several of its toughness indicators, Such as elongation at break, rapid cracking, impact strength of simply supported beams, etc.
After adding fillers, due to the good thermal stability of calcium carbonate, the thermal expansion coefficient and shrinkage rate of the product can be reduced in the same way, unlike glass fiber reinforced thermoplastics, which have different shrinkage rates in different aspects. Afterwards, the warpage and curvature of the product can be reduced, which is the biggest feature compared with the fiber filler, and the thermal deformation temperature of the product increases with the increase of the filler.
The filler has a certain ability to absorb rays, and generally can absorb 30% to 80% of incident ultraviolet rays to prevent the aging of plastic products.
Post time: Oct-27-2022