Calcium Carbonate in PVC Manufacturing: 14 Essential Quality Metrics and Their Impacts
As a critical filler in PVC processing, calcium carbonate reduces costs while enhancing mechanical strength, dimensional stability, and flame resistance. Here’s a deep dive into its 14 performance-defining parameters:
1. Color Tone
Test Method: Mix PVC/CaCO₃/stabilizer (100:25:4), analyze post-plasticization hues (gray/red/yellow shifts).
Significance: Affects final product aesthetics and batch consistency.
2. Apparent Density
Heavy Calcium (GCC): 0.8–1.3 g/cm³
Light Calcium (PCC): 0.5–0.7 g/cm³
Nano CaCO₃: As low as 0.28 g/cm³
Impact: Lower density improves resin dispersion but increases processing challenges.
3. Oil Absorption Value
GCC: 40–60 mL/100g | PCC: 60–90 mL/100g
Optimization: Surface modification reduces absorption, cutting plasticizer costs by 20–30%.
4. Crystal Morphology
Ideal Forms: Cubic/spherical particles minimize flow resistance and maintain surface gloss.
5. Particle Size
Nano CaCO₃: Optimal ~100 nm. Oversized particles (>200 nm) impair transparency; undersized (<50 nm) cause agglomeration.
6. Whiteness
GCC: 89–93% | PCC: 92–97%
Criticality: Determines suitability for colored/transparent products.
7. Sedimentation Volume
GCC: 1.1–1.4 mL/g | PCC: 2.4–4.0 mL/g
Rule: Higher volume = finer particles = premium performance.
8. Dispersion
Risk: Agglomerated nano-CaCO₃ (>500 nm clusters) causes defects under low-shear mixing.
9. Moisture Content
Threshold: ≤0.5% to prevent bubbles/voids during extrusion.
10. pH Value
GCC: 8–9 | PCC: 9–10
Risk: pH >10 degrades plasticizers, causing brittleness and yellowing.
11. Surface Free Energy
Balance: High energy improves resin bonding but promotes particle agglomeration.
12. Specific Surface Area
GCC: 1–2.1 m²/g | PCC: 5–87 m²/g
Trade-off: Larger area enhances reactivity but raises modification costs.
13. Impurity Limits
Critical Contaminants:
Fe₂O₃: >0.1% accelerates aging
MgO: >0.5% causes graying
SiO₂: >0.3% increases abrasion and thermal instability
14. Particle Size Distribution (PSD)
Optimal PSD: Narrow distribution (D90/D10 <5) ensures uniform reinforcement without viscosity spikes.
Source: Industry data compilation (for reference only; contact for removal requests).
Xinxiang Heying Machinery Equipment Co., Ltd. is located in Xinxiang City, Henan Province, known as the "Vibration Capital of China".
The company adheres to the concept of creating value through screening and is committed to providing one-stop services for screening industries worldwide. From design to production, from installation to post maintenance, every step demonstrates professionalism and dedication. The company mainly produces vibration machinery, screening equipment, and filtration equipment, with strong patent advantages. Advanced design technology, strong technical strength, complete production supply chain, comprehensive testing methods, and strict quality management system have jointly forged the company's excellent reputation. The company has been awarded honors such as "China Contract abiding and Creditworthy Enterprise, National Quality Trustworthy Product, National Quality Service Consumer Satisfaction Enterprise, and National Quality Inspection Stable Qualified Product", and has independent import and export rights. Its products are exported to North America, Western Europe, Southeast Asia and other regions.
To meet the needs of different industries, the company continues to research and develop, launch various equipment solutions, introduce advanced production technology, and provide personalized design. Whether in high standard industries such as pharmaceuticals and food, or diversified fields such as mining and metallurgy, the company's products can be seen everywhere. At present, the company's products cover four major series and are equipped with various types of equipment to meet production and ecological environment protection requirements. Excellent design and production teams will continuously provide high-quality and complete solutions for various screening scenarios.