Application Fields

Paper , plastics and paint are the three largest consumers of ground calcium carbonate.

Paper: Paper comprises a meshwork of cellulose fibers which are filled with fine mineral particles like calcite to maximize opacity as well as to make the finished paper brighter, whiter, smoother, receptive to ink, lightweight and cheaper.

From a mineral additive viewpoint there are four major paper grades comprising mechanical papers, both coated and uncoated, and woodfrees, again both coated and uncoated.Calcium carbonate can constitute 5 to 50% of the formulation and is invariably blended with kaolin as a glossing clay since carbonate coated paper is dull (printing and writing paper).

Plastic: Plastics are usually classified as thermoplastics (those that can be reshaped and remolded) and thermosetting plastics (permanently shaped).Calcium carbonate, often stearate coated to enhance dispersion, acts as a pigment and reduces the demand for the polymer, particularly in thermoplastics.

Loading of 5 to 35% are common in PVC sheet, pipe, window profiles, cables and 10 to 40% in polypropylene (automative, garden furniture, household appliances).Some of the major applications are;
Thermoset molded application 20 to 200 parts CaCO 3 Per 100 parts resin: auto front sections, dashboards, auto parts, bodies, pleasure and commercial boats, building panelsi plumbing equipment, tubs, shower enclosures, furniture parts, electrical appliances, pipes.

Thermoplastic: Thermoplastic applications 10 to 50 parts CaCO 3 per 100 parts resin: house sidings, gutters, moldings, wall covering, upholstery, floorings, carpets, structural forms, electrical wire coatings, plastic sheeting, auto parts, lumber replacements, shoe soles and heels, and houseware.

In paint, 10 to 35% calcium carbonate by volume may be incorporated in basic solvent or water based emulsions with up to 50% in textured coatings to reduce the quantity of TiO 2 required as well as to provide a matte finish.

Surface coated grades of calcium carbonate are used in polymers to encourage dispersion and in paint to reduce sedimentation, prevent floatation of color pigments and contribute to the full tinting power.

Ground calcium carbonate is by far the most widely used filler in sealents.In oleoresineous putty, calcite is used at levels as high as 85% by weight.

Another large application is in the production of dry wall compounds used to seal and finish joints between wallboard panels