Product Overview
As a high‑performance TiO₂ extender, anhydrous calcium sulfate is specially developed for thermoplastic color masterbatches and polymer composite materials. Relying on the particle space‑spacer effect, it alleviates the agglomeration of titanium dioxide particles. Under the premise of controllable loss of color and opacity, it helps customers optimize formulation costs. Featuring excellent whiteness, outstanding weathering resistance and low Mohs hardness, it causes little abrasion to processing equipment. Meanwhile, it meets the purity and food‑acid‑resistance requirements for food‑contact packaging. It is a cost‑effective functional mineral filler for the plastic masterbatch industry.
Note: This product is only for partial replacement of titanium dioxide and cannot completely substitute TiO₂. The recommended replacement ratio ranges from 10%‑25%. Formulation lab trials shall be conducted according to specific resin systems.
Key Advantages
✅ Partial TiO₂ replacement for cost optimization Tests in HDPE and HIPS thermoplastic systems prove that under 10%‑25% TiO₂ replacement, the opacity loss of finished products is minimal, ΔE is controllable, and L/a/b color parameters show no significant shift, balancing visual performance and raw‑material cost reduction.
✅ Low abrasion to protect processing equipment With a Mohs hardness of 2‑3, much lower than barite and quartz‑based fillers, it greatly reduces wear on screws and barrels during extrusion and injection molding, extending service life of processing equipment.
✅ High whiteness & good weather resistance Brightness: 98‑99; reflectance: 93.6. Delivers superior weathering performance, suitable for outdoor polymer masterbatches and modified plastics.
✅ Food‑contact grade purity High‑purity anhydrous calcium sulfate base with low impurity content and resistance to food‑grade acid, applicable for compliant food‑contact packaging formulations.
✅ Compatible with mainstream thermoplastic systems Perfectly fits HDPE (High‑Density Polyethylene) and HIPS (High‑Impact Polystyrene), widely used in various thermoplastic color concentrates.
Typical Technical Properties
| Item | Specification | Test Reference |
|---|---|---|
| Main Chemical Composition | CaSO₄ ≥98.7% | Chemical analysis |
| Specific Gravity | 2.96 | Pycnometer method |
| pH (10% Slurry) | 10.8 | Aqueous suspension test |
| Mohs Hardness | 2‑3 | Literature value |
| Refractive Index | 1.58 | Literature value |
| Oil Absorption | 24‑26 g/100g | ASTM D1483 |
| Blaine Surface Area | 10000‑14000 cm²/g | Blaine permeability method |
| Brightness | 98‑99 % | Beckman spectrophotometer, BaSO₄ standard |
| Median Particle Size | 4.3 μm | Microtrac particle size analyzer |
| Top Particle Size | 20.0 μm | Particle size analysis |
| Free Moisture | ≤0.1% | 45 ℃ moisture analyzer |
| Combined Moisture | ≤0.2% | 225 ℃ moisture analyzer |
Applications
- Thermoplastic Color Masterbatch: Partial TiO₂ extender for HDPE & HIPS color concentrates
- Food‑Contact Packaging Plastics: High‑purity filling system resistant to food acid
- General‑purpose Modified Thermoplastic Composites: Formulations requiring low equipment abrasion and high whiteness
Summary of Test Data
Referring to the test protocol of the reference product: Color concentrates were formulated at 52% pigment and 48% resin. Replacement gradients of 10%, 15%, 20% and 25% of titanium dioxide were set respectively. Samples were extruded by single‑screw extruder, diluted at 50:1 ratio and injection‑molded into test specimens. Color and opacity were measured via Datacolor spectrophotometer.
Test Conclusion: Within 25% replacement ratio, opacity loss is negligible for both HDPE and HIPS systems; ΔE is within acceptable range with minor visual change of finished articles.
Usage Recommendations
- Recommended TiO₂ replacement range: 10%‑25%. Replacement ratio above 25% will cause obvious opacity drop.
- Evaluate dosage of dispersant and ensure sufficient compounding & extrusion. Lab trials are strongly suggested before mass production.
- Storage: Store indoors under dry conditions. Pallet stacking height shall not exceed 2 pallets. Avoid direct draft. Apply first‑in‑first‑out inventory management.
