1. Particle Size and Particle-Size Distribution

Particle size should be selected according to the PVC formulation and final product requirements.

A very fine calcium carbonate grade has a high specific surface area. This can increase the interaction between calcium carbonate and other formulation components.

On the other hand, excessive coarse particles may negatively affect dispersion and can become more noticeable in the finished product.

For this reason, PVC manufacturers should review both D50 and D97, rather than relying on a single mesh or micron value.

2. Moisture Control

Moisture is another important quality parameter.

Excessive moisture in mineral filler can create processing issues and affect feeding, dispersion, and overall formulation stability.

For consistent industrial production, calcium carbonate should therefore be stored and packed properly, and the moisture specification should remain stable between batches.

3. Whiteness and Appearance

For white PVC pipes and profiles, calcium carbonate whiteness can influence the appearance of the final product.

However, whiteness should not be considered independently.

The final color of PVC depends on the complete formulation, including:

• PVC resin
• Stabilizer
• Titanium dioxide
• Calcium carbonate
• Processing aids
• Pigments and other additives

Therefore, a high-whiteness calcium carbonate grade should be evaluated within the customer's complete formulation.

4. Mineral Purity

Natural calcium carbonate is produced from mineral resources, so the composition of the raw material is important.

Besides CaCO₃, manufacturers may monitor components such as:

• MgO
• SiO₂
• Fe₂O₃
• Other mineral impurities

The acceptable level depends on the application and formulation.

For high-volume PVC production, stable chemical composition is particularly important because changes in mineral composition may affect formulation consistency.

5. Surface Treatment

For some PVC applications, coated calcium carbonate, commonly surface-treated with fatty acids such as stearic acid, may be considered.

Surface treatment can improve the interaction between calcium carbonate and the polymer system and may influence dispersion and processing behavior.

However, coated calcium carbonate is not automatically the correct solution for every PVC formulation.

The decision should be based on the resin system, filler loading, processing conditions, and desired product performance.

6. Filler Loading Level

The appropriate calcium carbonate loading level depends on the formulation.

Increasing filler loading changes the balance between PVC resin and mineral filler and may influence:

• Tensile strength
• Impact performance
• Elongation
• Stiffness
• Processing torque
• Fusion behavior
• Product density

Therefore, calcium carbonate should be evaluated at the actual loading level used in production, rather than only through laboratory testing at an arbitrary dosage.

A Practical Evaluation Method

When introducing a new calcium carbonate supplier, PVC manufacturers can conduct a controlled comparison:

Step 1: Compare the supplier's COA and technical specifications.

Step 2: Test particle-size distribution rather than only nominal micron size.

Step 3: Run the material using the existing PVC formulation.

Step 4: Monitor processing parameters such as torque, melt pressure, and extrusion stability.

Step 5: Evaluate the finished pipe or profile for appearance and mechanical properties.

Step 6: Compare batch-to-batch consistency after repeated production trials.

This approach provides a much more meaningful assessment than comparing calcium carbonate prices alone.

Tan Ky Mineral – Calcium Carbonate Supplier from Vietnam to India

Tan Ky Mineral is a Vietnam calcium carbonate manufacturer and supplier serving industrial customers requiring calcium carbonate powder for PVC and other applications.

We work with customers to identify suitable specifications according to their production process and application.

For Indian PVC manufacturers, we can provide technical information for calcium carbonate grades including particle size, whiteness, moisture, chemical composition, packaging, and other quality parameters.

For PVC pipe and profile manufacturers in India, choosing the right calcium carbonate grade starts with understanding the formulation—not simply choosing the lowest price.

Tan Ky Mineral – Vietnam Calcium Carbonate Manufacturer & Supplier.

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