Main applications: PVC profiles, pipes; Rubber particles of wire and cable skin; Production of PVC film (calendering film), shoe manufacturing (such as PVC sole and decorative patch), etc. It is suitable for modification of engineering plastics, PP, PE, PA, PC, etc.
Application characteristics: due to the lipophilic and hydrophobic surface of active nano calcium carbonate and good compatibility with resin, it can effectively improve or adjust the stiffness, toughness, finish and bending strength of products; It can improve the processing performance, improve the rheological performance, dimensional stability and heat stability of products. It can fill, strengthen and toughen. It can replace some expensive fillers and additives and reduce the amount of resin, so as to reduce the production cost and improve the market competitiveness.
The most mature application industry of nano calcium carbonate is the plastic industry, which is mainly used in high-grade plastic products.
Nano calcium carbonate is also called ultra-fine calcium carbonate. The name of the standard is ultrafine calcium carbonate. The most mature application industry of nano calcium carbonate is the plastic industry, which is mainly used in high-grade plastic products. PVC plasticized sol for automobile internal sealing.
It can improve the rheology and formability of plastic masterbatch. As a plastic filler, it can toughen and strengthen the plastic, improve the bending strength and bending elastic modulus, thermal deformation temperature and dimensional stability, and endow the plastic with thermal hysteresis.
Because nano-sized ultrafine calcium carbonate has high gloss, low wear rate, surface modification and oil repellency, it can be filled in polymers such as PVC, polypropylene and phenolic plastics. Since 2005, it has been widely used in PVC cable filler.
Calcium carbonate is widely used in filling polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), acrylonitrile butadiene styrene copolymer (ABS) and other resins. Adding calcium carbonate can improve some properties of plastic products and expand their application range. In plastic processing, they can reduce resin shrinkage, improve flow distortion and control viscosity. It can also play the following roles:
1. Improve the dimensional stability of plastic products
The addition of calcium carbonate plays a skeleton role in plastic products and plays a great role in the dimensional stability of plastic products.
2. Improve the hardness and rigidity of plastic products
In plastics, especially in soft PVC, the hardness increases with the addition of calcium carbonate, and the elongation decreases with the increase of hardness. Calcium carbonate with fine particles and large oil absorption value has a large growth rate of hardness. On the contrary, calcium carbonate with small particle crude oil absorption value has a small hardness growth rate. In soft PVC, the hardness growth rate of heavy calcium carbonate is the smallest, and precipitated calcium carbonate (light) is the second.
Generally, the plastic (resin) of calcium carbonate can not play a reinforcing role, and the particles of calcium carbonate can often be infiltrated by the resin. Therefore, the normal function of calcium carbonate addition is to increase the rigidity, elastic modulus and hardness of the resin. With the increase of the addition amount, the high tensile strength and extreme elongation decreased.
The hardness of different calcium carbonate will be different with different addition amount.
3. Improve plastic processability
The addition of calcium carbonate can change the rheological properties of plastics. Calcium carbonate powder is often added in a large amount, which is conducive to its mixing with other components and the processing and forming of plastics.
The addition of calcium carbonate, especially after surface treatment, can not only improve the hardness of the product, but also improve the surface gloss and surface flatness of the product.
The addition of calcium carbonate can reduce the shrinkage, linear expansion coefficient and creep properties of plastic products, and create conditions for processing and forming.
4. Improve the heat resistance of plastic products
Adding calcium carbonate to general plastic products can improve the heat resistance. For example, adding about 40% calcium carbonate to polypropylene can improve the heat resistance by about 200 ℃. When the filling ratio is ≤ 20%, the heat-resistant temperature increases by 8 ~ 130 ℃.
5. Improving astigmatism of plastics
In plastic products, some products require whitening and opacity, and some want extinction. The addition of calcium carbonate can play a certain role in this regard.
Calcium carbonate with whiteness above 90 has obvious whitening effect in plastic products. With titanium dioxide and lithopone, the extinction of plastic products has been greatly improved.
Calcium carbonate can be added to calcium plastic paper, LDPE and HDPE films to achieve astigmatism and extinction, making it suitable for writing and printing.
Calcium carbonate with better whiteness can also replace expensive white pigments.
6. It can make the product have some special properties
The addition of calcium carbonate to the cable material has a certain insulating effect. The addition of calcium carbonate can improve the electroplating and printing properties of some products.
Micro or ultra-fine calcium carbonate added to polyvinyl chloride (PVC) has a certain flame retardant effect.
7. Reduce the cost of plastic products
The price of ordinary light calcium carbonate and heavy calcium carbonate is far lower than that of plastic. The addition of calcium carbonate will reduce the cost of plastic products. Therefore, calcium carbonate is called filler or extender abroad.
At this stage, the main goal of adding calcium carbonate is to reduce the cost of plastics. With the improvement of surface properties of calcium carbonate and the control of shape and particle size, calcium carbonate will gradually become a functional filler for the purpose of strengthening or giving functionality.
Calcium carbonate is the most commonly used filler in the production and processing of PVC products. Its purpose is mostly to increase PVC products and reduce production costs.