6 key parameters of calcium carbonate in plastic filling
6 key parameters of calcium carbonate in plastic filling
In plastic filling modification, the performance parameters of calcium carbonate have an important impact on the quality and processing technology of the final product.
1. Calcium content
Calcium content is an important technical indicator for measuring the quality of calcium carbonate. The calcium content of modified masterbatch is usually higher, generally required to reach more than 98%. The higher the calcium content, the more stable the processing performance of calcium carbonate. When the calcium content is low, the proportion of impurities such as heavy metals and other non-metallic substances increases, which not only reduces the applicability of calcium carbonate, but also may have an adverse effect on the processing technology, resulting in a decrease in product quality and even damage to processing equipment. Therefore, ensuring a high calcium content of calcium carbonate is crucial for plastic filling processing.
2. Whiteness and hue
The whiteness of calcium carbonate is directly related to the whiteness and coloring properties of the modified masterbatch, and its requirements are extremely strict. Taking 400 mesh calcium carbonate as an example, its whiteness must reach more than 95%, and some calcium carbonate processed from high-quality ores can even reach 97%. In order to further improve the whiteness of the product, some modified masterbatch manufacturers will use fluorescent whitening agents. However, this practice has certain risks:
High temperature reaction risk: The chemical composition of fluorescent whitening agents is easily decomposed under high temperature and high shear conditions, which may cause the product to turn yellow, agglomerate or disperse poorly.
Safety issues: For plastic products that come into contact with the human body or involve health and safety, fluorescent whitening agents may cause irritation and should not be widely used.
Hue is also an important technical indicator of calcium carbonate, and its determining factors mainly include the structure and source of the ore. These factors directly affect the color, gloss and coloring effect of plastic products. Therefore, the whiteness and hue of calcium carbonate are key indicators that cannot be ignored in the selection process of modified masterbatch. By reasonably selecting the raw material source and processing technology of calcium carbonate, the appearance quality and market competitiveness of plastic products can be effectively improved.
