Applications of calcium carbonate masterbatch in the plastic industry

Calcium carbonate masterbatch is made of calcium carbonate, base resins and several plastic additives. Calcium carbonate (CaCO₃) powder used in calcium carbonate masterbatch production has the natural origins. It exists in many forms such as calcite, limestone, chalk, marble or aragonite, or in the form of impurities and minerals such as dolomite. For thousands of years, CaCO₃ has been one of the most useful minerals for humans, in different fields. And so far, one of the industries that use CaCO₃ the most is probably the filler masterbatch industry.

Calcium carbonate masterbatch is the component bringing profitability for investors

After the resin, CaCO₃ also plays an important role in making filler masterbatch. Among the fillers, calcium carbonate masterbatch is the most commonly used type one especially the plastic and rubber industry.

Regarding to plastic fillers, they are often insoluble minerals that are added into the primary plastic to increase the volume for plastics. They play many roles in masterbatch production, from reducing production costs to improving product features such as increased durability and rigidity. However, everything has 2 sides. When using fillers at high concentrations beyond the ideal ratio, important physical properties of products such as impact resistance will be changed in the direction of disadvantage. Therefore, adding CaCO₃ as filler requires a balance between cost and dosage compared to other ingredients.

From calcium carbonate powder to producing calcium carbonate masterbatch

To produce calcium carbonate masterbatch, manufacturers often use CaCO₃ powder from limestone quarries. Limestone resources in Vietnam are quite abundant in reverse. There are about 125 limestone quarries that have been searched with estimated reserves of about 13 billion tons, distributed mainly in the northern regions and southernmost provinces.

Calcium carbonate in form of powder is classified into two basic groups:

• Ground calcium carbonate (GCC): compound produced from natural limestone undergoes grinding, impurities and particle size separation according to different uses. This is the kind we used to produce calcium carbonate masterbatch.
• Precipitated calcium carbonate (PCC): Limestone is calcined to collect calcium carbonate powder and CO₂. Quicklime undergoing hydration process will result in calcium hydroxide, which will react with CO₂ and finally resulted in precipitated calcium carbonate. PCC powder is more expensive compared to GCC powder. So instead of being applied to filler masterbatch field, this kind of calcium carbonate is used to produce cosmetics and food.

The outstanding application of calcium carbonate masterbatch in the plastic industry

Masterbatch is considered as input material with granular shape used for other industries. Masterbatch not only helps manufacturers reduce production costs but also improves the hardness, material surface and reduces shrinkage of the finished products. Thanks to these advantages, calcium carbonate masterbatch has many applications in various production areas.

As we metioned above, GCC is used to produce filler master batch. When GCC is applied as a filler in plastics, it must undergo a melting process with plastic substrate to create granules called filler. Then, CaCO3 filler masterbatch is used to produce thin/thick films, evaporate plastic films, heat-resistant films, etc. In addition, plastic fillers are also involved in the production processes of PE or PP plastic with the role of preventing segmentation or fibrillation. CaCO₃ masterbatch is also very useful for manufacturing plastic products by injection molding technique, so it is widely used in the production of spare parts, equipment, household products, etc.