6 key parameters of calcium carbonate in plastic filling-5
Effect of other components in calcium carbonate on performance
The chemical components, metal impurities and other components in calcium carbonate have a certain impact on its quality and application in plastic modified masterbatch and plastic products. Common impurities include magnesium oxide (MgO), silicon dioxide (SiO2), ferric oxide (Fe2O3), aluminum oxide, and trace amounts of heavy metals (such as aluminum, arsenic, mercury, etc.). The content of these components varies depending on the origin and type of ore.
1. Magnesium oxide (MgO)
Characteristics: Low hardness, whiteness slightly lower than calcium carbonate, chemical stability and processing properties similar to calcium carbonate.
Impact: Generally, it has little impact on the performance of calcium carbonate and will not significantly change its performance in modified masterbatch.
2. Silica (SiO2)
Characteristics: It is a natural quartzite with small specific surface area, good fluidity, but high hardness (Mohs hardness 7).
Impact: Excessive hardness will lead to increased equipment wear, especially when the coating is uneven or the amount of plasticizer is insufficient. In high-speed processing of polypropylene flat wire, SiO2 may damage the cutting tool and affect production efficiency.
3. Iron oxide (Fe2O3)
Characteristics: The content is usually low, but it easily reacts with chemical additives.
Impact: It will turn yellow after thermal decomposition, reducing the whiteness and appearance quality of the modified masterbatch.
4. Control of other ingredients
The lower the SiO2 and Fe2O3 content, the more stable the quality of the modified masterbatch. Detection can be done by:
SiO2 content: Mix 5% dilute hydrochloric acid solution with calcium carbonate and observe the amount of precipitation in the solution to evaluate the content.
Fe2O3 content: When the color of the solution is slightly yellow, it indicates that the Fe2O3 content is high.
Summarize
Controlling the content of impurities in calcium carbonate, especially the ratio of SiO2 and Fe2O3, is crucial to improving the quality and production efficiency of modified masterbatch. Optimizing raw material selection and process flow can effectively reduce the impact of impurities on equipment and product performance.
