Calcium Carbonate (CaCO₃) is one of the most widely used mineral fillers in the global paper industry. Its ability to enhance brightness, opacity, printability, and cost efficiency makes it an essential raw material in both traditional and modern papermaking processes. With continuous advancements in coating and filler technologies, calcium carbonate has become a key contributor to high-quality printing papers, packaging boards, and tissue products.

1. Role of Calcium Carbonate in Papermaking

In the paper industry, calcium carbonate serves as both a filler and a coating pigment:

● As a filler

Added directly into the pulp, CaCO₃ increases:

• Brightness and whiteness

• Opacity, helping to reduce show-through

• Smoothness and softness of paper surface

• Bulk and stiffness, especially in packaging grades

• Cost effectiveness, as it replaces more expensive pulp fibers

                                    

● As a coating pigment

Coated papers require a smooth, bright surface for high-quality printing. Ground Calcium Carbonate (GCC) and Precipitated Calcium Carbonate (PCC) provide:

• Excellent print gloss

• Improved ink absorption

• High color reproduction accuracy

• Enhanced surface strength

2. Types of Calcium Carbonate Used in Paper Industry

1) Ground Calcium Carbonate (GCC)

Produced by grinding natural limestone or marble.
Characteristics:

• Irregular particle shape

• Excellent brightness

• High opacity

• Cost-efficient

GCC is preferred in printing & writing paper, packaging paper, and tissue.

2) Precipitated Calcium Carbonate (PCC)

Manufactured through a chemical precipitation process, allowing control of crystal shape and size.
Characteristics:

• Very high brightness

• Uniform particle distribution

• Tunable properties (scalenohedral, rhombohedral, spindle shapes)

• Superior optical performance

PCC is popular for premium coated papers and high-end printing grades.

3. Key Benefits of CaCO₃ for Paper Manufacturers

✔ Cost Reduction

Using CaCO₃ as filler decreases the need for expensive pulp, reducing production costs.

✔ Better Optical Properties

CaCO₃ increases brightness (ISO 95–98%), whiteness, and opacity—key requirements for printing and packaging.

✔ Improved Mechanical Properties

• Higher paper stiffness and bulk

• Stable ash content

• Better dimensional stability

✔ Environmentally Friendly

CaCO3 offers:

• Lower energy consumption during production

• Reduced carbon footprint compared to other pigments

• Compatibility with alkaline papermaking, which is more sustainable than traditional acidic processes

4. Applications of Calcium Carbonate in Paper Industry

Calcite Powder is widely used in:

• Printing and writing papers

• Coated woodfree paper (CWF)

• Coated board and packaging board

• Tissue and hygiene products

• Newsprint

• Specialty papers

Different grades of GCC or PCC are selected depending on brightness, particle size, and binder systems.

5. Choosing the Right CaCO₃ Grade

When selecting CaCO₃ for paper production, manufacturers often evaluate:

• Particle size (D50, D97)

• ISO brightness

• Whiteness index

• Oil absorption

• Moisture content

• Purity (CaCO₃ > 96–98%)

• pH and dispersion performance

• Abrasion levels

Proper selection improves paper quality, machine speed, and coating efficiency.

Conclusion

Calcium Carbonate is an indispensable material in the paper industry due to its ability to improve paper quality while reducing production costs. Whether in the form of GCC or PCC, CaCO₃ delivers optimal brightness, opacity, surface properties, and print performance—making it a key ingredient for modern papermaking.

VIET NAM TECHNOLOGY MINERAL JSC – SHC GROUP

Mr. Harry – International Sales Manager
WhatsApp: +84 936 165 098
Email: export8@shcgroup.vn