Calcium Carbonate Supplier


Calcium carbonate occurs as calcite, a natural mineral and is also available as a synthetic version created by chemical precipitation. Ground calcium carbonate is known as GCC whereas the precipitated version is referred to as PCC. The synthetic version is preferred when exceptional purity, higher brightness or finer particle size are required. The natural, ground version tends to give blocky irregular particles whereas the precipitated version (PCC) exhibits particles that are somewhat more spherical.

Calcium carbonate is widely used for three main reasons:

  • High whiteness
  • Abundant
  • Low cost


As calcium carbonate is so affordable and widely available, it is the default choice of mineral filler for applications in plastics, paints, coatings and adhesives. It has average density for a mineral filler but when used at high loading levels from 60-80 weight percent, it adds significant density to plastics. This enables sound deadening in sheet-based products as well as PVC flooring and tiles. Levels of 20-40% by weight are most commonplace in plastics like PE, PP and PVC but calcium carbonate is not recommended for nylons and polyesters.

As ground calcium carbonate particles are blocky with low aspect ratio, they do not reinforce meaning that the stiffness will increase substantially but the strength of the plastic will not increase. Low aspect ratio / isotropic particles give good impact resistance as well as reduced shrinkage and coefficient of thermal expansion. Even more importantly, the shrinkage is even in all directions, so no warping occurs.

The average refractive index of CaCO3 is significantly higher than that of most plastics and coatings, which leads to light scattering and thus a white appearance. It is not considered a strong pigment but does contribute to opacity. Because calcite has three different refractive indices, it is not possible to match all three to the single refractive index of the surrounding matrix. Thus, truly transparent composites containing calcite are not possible.

One important application of calcium carbonate is in the manufacture of breathable films for diapers and other related products. A fine surface treated calcium carbonate is used for the application, where the particle size must be tightly controlled and a surface treatment but be applied to the particles. The role of the surface treatment is twofold. Firstly, it aids with dispersion but more importantly, it acts to decrease bonding between the filler and the host polyolefin polymer. When stretched, the filler particles debond creating a porous film and it is the porous structure which imparts breathability.

Miscellaneous applications include acid scavenging (because it is an alkaline filler), for example, calcium carbonate is usually present in uPVC and plasticized PVC formulations because it absorbs any hydrochloric acid generated during processing and thereby protecting the plastic from discoloration.

Calcium carbonate can be used in polyesters such as PET, PBT, PLA, PHB and so on but a surface treatment is needed to ensure the best properties and to prevent hydrolysis of the polymer backbone.

In other plastics, surface treatment is used on the particles giving benefits such as higher flow (for higher loadings), better dispersion leading to improved impact resistance and elongation as finally it helps to maximize gloss. Kish Company has decades of experience in stearic acid and customized surface treatments.

Calcium carbonate is a safe mineral and can even be ingested as supplement. It is GRAS (Generally Recognized As Safe) according to the US FDA.

Need help choosing a product?

When looking for the most suitable product for your application, you can count on The Kish Company’s product portfolio and experience. We help keep it simple.

Request a Sample

Technical partnering is a key to our committed continue success with our clients.