Calcium carbonate is one of the most widely used fillers in plastics. It is cheap, widely available, and has a low relative density. In addition to its incremental effect in plastics, it also has the effect of improving processing performance and product performance. This material has a softer texture and causes less wear on kneaders and forming machines. At the same dosage, the surface scratching and bending whitening properties of products filled with light calcium carbonate are smaller than those filled with heavy calcium carbonate. The biggest feature of light calcium carbonate is its reinforcing effect, which can improve the impact strength of products. Heavy calcium carbonate used in plastics can reduce costs, has good affinity with resins, has high dispersion, has a refractive index similar to that of plastics, is easy to color, and can improve the strength and stability of plastic products. The most mature industry for the application of nano calcium carbonate is the plastics industry, where it is mainly used in high-end plastic products.
1. Polyvinyl chloride (PVC)
Calcium carbonate filled PVC is made by kneading PVC, calcium carbonate (such as heavy calcium carbonate, light calcium carbonate, micronized calcium carbonate, precipitated calcium carbonate, activated calcium carbonate, etc.) and other additives according to the ingredients ratio. , mixed, and then granulated, extruded or injection molded into the required products; it can also be rolled and pressed into sheets or plates, which are flame-retardant, resistant to acids, alkalis and chemicals, water-resistant, moisture-proof, sound insulation and coloring It has the characteristics of good durability, and also has the advantage of being cheaper than ordinary PVC plastic.
Calcium carbonate is used to fill polyvinyl chloride. It can be used in hard products such as plates and pipes, and in soft products such as wire coverings and artificial leather. It can improve the color stability of the products. Used in polyvinyl chloride paste as a viscosity regulator. This product has a high oil absorption value, absorbs a large amount of plasticizer, and has poor dispersion uniformity in soft polyvinyl chloride. When the mixing amount is large, the surface smoothness of extruded products will be reduced. Used together with white carbon black, it can improve dispersion uniformity. Calcium carbonate filled PVC hard products can replace steel and wood in construction projects, transportation and furniture production, such as making door and window profiles, ceilings, partition boards, corrugated boards, floors, car and boat cabin boards, and wire ducts. Boards, furniture, board-frame or corrugated packaging boxes, building drainage pipes and industrial sewage pipes, etc. At the same time, it can also make soft products such as films, artificial leather, sheets, wire sheaths and opaque hoses.
2. Polyethylene (PE)
Calcium carbonate filled polyethylene plastic is a composite material with a large amount of calcium carbonate evenly distributed in a small amount of resin continuous phase. In addition to combining the properties of plastic, wood and paper, it also has properties such as cold resistance, water resistance, heat resistance, shock resistance, and sound insulation. The product does not produce corrosive smell, but is easy to burn. The combustion performance is similar to that of paper and wood. It has good thermal stability, mechanical properties and high softening point. Maintains high strength at low temperatures. If foaming agent is added, lightweight wood substitutes can also be produced. Its physical and mechanical properties such as rigidity, hardness, compressive strength, dimensional stability and heat resistance are superior to plastic products made of pure polyethylene resin. It has small creep property and molding shrinkage, good processing performance, and is easy for secondary processing. Its main disadvantage is that it loses the original luster of the plastic and the color is less bright.
Calcium carbonate filled polyethylene plastic is made by mixing 10%~50% polyethylene (HDPE, LDPE) and 50%~90% (weight) calcium carbonate and additives in a certain ratio at 85~100℃, and then at 180~ Mix at 200°C for a certain period of time to obtain the mixed material, and then perform extrusion, granulation, sheet drawing, etc. according to different requirements to make semi-finished products, and finally obtain them through different methods such as molding, injection molding, extrusion, calendering, and foaming. Various calcium plastic products.
3. Polypropylene (PP)
The performance of calcium carbonate filled polypropylene has a great relationship with the filler performance, content, type, particle shape and size, surface state, and the dispersion state of the filler particles in the resin. At the same time, whether the components can be fully mixed evenly is also one of the important factors. Generally speaking, calcium carbonate filled polypropylene has good temperature resistance, mechanical properties (tensile strength, flexural strength, flexural modulus, impact strength, etc.) and crystallization properties, low molding shrinkage, good dimensional stability, and high hardness. In some cases, when it is necessary to use filled polyethylene with certain flame retardancy, a certain amount of flame retardant must be added. In particular, nano-calcium carbonate-filled polypropylene treated with coupling agents has excellent various properties and has become a hot topic in application and research in recent years.
Calcium carbonate-filled polypropylene is made by efficiently mixing polypropylene resin with a certain amount of calcium carbonate and other fillers, as well as necessary additives, and extruding and granulating them to obtain different grades of filled polypropylene.
Calcium carbonate-filled polypropylene can be used as integrated circuit I-C pallets, dipsticks, copier parts, microwave oven parts, toys, car guards and exterior decoration, electrical equipment parts, etc. Self-extinguishing calcium carbonate-filled polypropylene has good high-frequency electrical insulation, electrical properties that are less affected by temperature and humidity, and FV-0 group flame retardant properties, so it is suitable for TV output high-voltage packages, coil bobbins, and motor protection. Various electrical components such as switch housings and terminal covers, as well as transportation, construction, textile and other sectors that have high requirements for flame retardancy.