Barium Sulfate (BaSO₄) for Rubber & Plastics 

Barium Sulfate (BaSO₄) for Rubber & Plastics — Improving Dispersion, Enhancing Gloss, Increasing Rigidity

High-purity barium sulfate functional filler specially designed for the rubber and plastics industry. Designed for PP, modified PP, PET, PA, ABS and other plastic and rubber products.

The following is a detailed technical breakdown from four dimensions: physical and chemical properties, parameter analysis, application advantages, and practical considerations.

I. Physical & Chemical Properties and Inherent Advantages

1. Essential Characteristics: High Whiteness & High Purity  
- Chemical composition: Barium sulfate (BaSO₄) content up to 98.0% in main grades.  
- Physical appearance: White powder.  
- Whiteness (L* value): ≥ 98% for all grades. This high whiteness ensures a pure base color in white or light-colored rubber/plastic products, effectively reducing formulation costs.  
- Relative density: 4.5, providing higher bulk density and filling weight per unit volume, especially suitable for high-density products (e.g., counterweights, fishing sinkers, marine parts).

2. Stability & Chemical Resistance 
- Insoluble in water, ethanol, and acids; only soluble in hot concentrated sulfuric acid.  
- This chemical inertness gives the filled products strong acid/alkali resistance and salt spray corrosion resistance, widely used in outdoor products, chemical containers, and automotive parts.

3. Narrow Particle Size Distribution
- Fine grinding and classification processes ensure a concentrated particle size distribution without coarse particles.  
- Narrow particle size distribution guarantees uniform dispersion of the powder in the rubber/plastic matrix, avoiding “fish eyes” or “white spots” caused by uneven particle sizes.  
- Effectively reduces sedimentation and layering during filling, ensuring product performance consistency.

4. Odorless
- High-temperature calcined, free of volatile organic compounds and sulfide residues.  
- No irritating odor released during production and processing.

5. High Gloss
- When used at the same loading in PP, PET and other substrates, the surface gloss of the finished product is significantly higher than that of ordinary barium sulfate filled systems.  
- Especially suitable for injection-molded parts requiring a high-gloss appearance, enhancing the visual quality of end products.

II. Parameter Analysis

| Parameter | Value |
| Barium sulfate content (dry basis) | ≥ 98.0% |
| Whiteness (L*) | ≥ 98.0% |
| Oil absorption (g/100g) | 14–16 |
| pH (10% suspension) | 6.5–8.0 |
| Fineness (45μm sieve residue) | ≤ 0.06% |
| Particle size D50 (μm) | 0.7–0.8 |

III. Summary of Practical Application Benefits

Introducing this grade of barium sulfate into rubber and plastic products provides the following benefits:

1. Modulus / Rigidity Improvement
- Adding barium sulfate to PP increases flexural modulus (specific values depend on the matrix and coupling agent). Suitable for automotive interior parts, electronic product housings.

2. Improved Surface Gloss
- Compared to calcium carbonate, at the same filling ratio, barium sulfate filled products show higher specular gloss.

3. Molding Shrinkage Control
- The rigid structure of barium sulfate inhibits the shrinkage rate of rubber and plastics. For products requiring high dimensional stability (e.g., electrical connectors, precision parts), barium sulfate can replace part of the glass fiber, reducing cost and minimizing anisotropic shrinkage.

4. Barrier Performance 
- After filling with flake/high-density powder, the tortuosity of gas and solvent paths is increased, effectively improving oxygen and water vapor barrier properties for flexible packaging and industrial films.

IV. Practical Considerations / Notes
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We are a Barium Sulfate Source Factory – Quality Commitment
As an original manufacturer deeply engaged in the barium sulfate industry for many years, Xintu Chemical has three core advantages:

1. Full industry chain control: Own advanced technology, annual output of 60,000 tons, stable supply, obvious price advantages.  
2. Customized service: Can provide different particle sizes, whiteness, etc., according to customer needs.  
3. Technical support: Professional team provides formulation optimization advice, free sample testing, and solves application problems.