Basic requirements for calcium carbonate used by plastics processing enterprises Calcium carbonate as a powder material commonly used in plastics has many advantages that other powder materials do not have, such as high whiteness, easy surface organic treatment, processing equipment and molds. It is light in wear, good in fluidity in molding processing, and rich in resources and low in price. It has become the first choice of inorganic mineral powder materials in the plastics processing industry. According to the current thinking and experience of plastic processing enterprises, the factors considered in the selection of calcium carbonate constitute the basic requirements for calcium carbonate. Aluminium Alloy Sliding Door Lock Aluminium Alloy Sliding Door Lock,Bilateral Automatic Bathroom Lock,Commercial Sliding Door Locks,Stainless Steel Keyless Door Lock BOGO HARDWARE & FITTING CO.,LTD , https://www.bogohardware.com
1) Low price Although calcium carbonate is very cheap compared to synthetic resin, it is also cheaper than any other powder material. However, due to the large number of suppliers, the company is still price sensitive and can be used under the premise of being usable. Cheaper is better.
2) The higher the whiteness, the better the color of calcium carbonate itself is whiter than other inorganic mineral powder materials. It can be 90 degrees from the specific value. The effect of whiteness on the properties of filled plastic is not significant, but Plastic processing companies still hope that the higher the whiteness, the better, based on the following reasons:
1 Higher whiteness indicates higher purity and lower content of other mineral components of non-calcium carbonate.
The graying of the calcium powder indicates that there may be free carbon, yellowing indicates that there may be more iron compounds, and darkening indicates that the silicon content is high. High levels of impurities can sometimes affect the color, appearance, and heavy wear of processing equipment and molds during processing.
2 The higher the whiteness, the better the visual impression, and the higher the grade.
3 The higher the whiteness, the more positive and stable the uniform color after matching with other pigments.
3) The particle size and its distribution should be suitable as a kind of powder material. First, it is necessary to consider the particle size of the particle itself and the proportion of particles in a certain size range under the test conditions. The second is to consider from the practical application. Whether the presence of these particles is agglomerated, can the agglomerates disperse during the processing of the filling system, and are scattered in the "ocean" of the base plastic like the large and small islands in the sea?
1 From the cost point of view, as long as it can meet the requirements of use, it is better to use coarse, not fine. For example, the heavy calcium used for the production of flat yarn for polypropylene woven bags (cloth) can be 400 mesh. If a finer calcium powder is used, not only the price itself is significantly increased, but also when the filler masterbatch is produced. It consumes more auxiliaries and carrier resins, which is not worth the candle.
2 From the performance of the filled plastic, it is better to use a finer particle size on the premise that the cost can be appropriately increased.
3 From the perspective of processing fluidity, under the premise of controlling the maximum particle size, the average particle size is larger.
For calcium carbonate products of the same particle size, the particle size distribution may vary widely, which is reflected in the average particle size. For plastic products requiring good processing fluidity (such as injection molded products, cast PE film, etc.), it is not possible to use calcium powder with an average particle size too small. If possible, it is best to control the maximum particle size. Under the premise, the particles of small particle size are separated. This is because the more particles having a small particle size, the worse the processing fluidity of the filling system.
4 The particle size and distribution of light calcium carbonate and nano calcium carbonate sold as commodities are “the difference between heaven and earth†in the state in which the dispersed phase exists in the plastic matrix. If the agglomeration problem is not solved well, it will not Shows the advantage of small particle size.