Calcium carbonate, also known as calcite when in its crystalline form, is a versatile mineral that finds numerous applications in industries such as leather, rexine, and PVC. Here's how it can be used in each of these sectors:

Application: In the leather industry, calcium carbonate can be utilized in various stages of leather processing.

Tanning: In the tanning process, calcium carbonate may be used as a neutralizing agent to adjust the pH of the leather after the acidic pickling stage. This helps to stabilize the collagen fibers and prepare the leather for subsequent treatments.

Filling and Weighting: Calcium carbonate can be added to leather formulations as a filler to increase bulk and weight. This practice, however, is less common due to concerns about reducing the natural properties of leather.

Finishing: In finishing processes, calcium carbonate may be included in formulations for topcoat or finishing agents to achieve specific properties such as opacity, smoothness, or matt appearance.

Application: In the rexine industry, calcium carbonate is commonly used as a filler and reinforcement agent in the production of synthetic leather materials.

Filling: Calcium carbonate serves as an inexpensive filler to reduce production costs while maintaining desired mechanical properties in rexine materials. It helps to increase bulk and improve dimensional stability.

Reinforcement: Calcium carbonate can enhance the strength and stiffness of rexine products when used as a reinforcement agent in polymer matrices. It improves resistance to tearing, puncture, and abrasion.

Surface Appearance: Calcium carbonate may also contribute to the surface texture and appearance of rexine materials, depending on its particle size and distribution.

Application: In the PVC industry, calcium carbonate is widely used as a filler, extender, and rheology modifier in PVC formulations.

Filler: Calcium carbonate is added to PVC formulations as a cost-effective filler to replace more expensive polymer resins while maintaining desired mechanical properties. It helps to reduce material costs without sacrificing performance.

Extender: Calcium carbonate extends the volume of PVC compounds, allowing for increased production efficiency and reduced material consumption.

Rheology Modifier: Calcium carbonate influences the viscosity and flow properties of PVC melts, affecting processing characteristics such as extrusion, molding, and shaping.