Introduction: In the fields of plastic modification, color masterbatch, and powder coating supporting materials, barium sulfate is one of the most widely used functional inorganic fillers. Many customers are curious about the actual differences between pure resin masterbatch without barium sulfate and modified barium sulfate filled masterbatch in terms of surface appearance, mechanical properties, weather resistance, processability and overall cost. Based on actual sample tests and microscopic analysis, this article intuitively explains the core performance advantages of barium sulfate filled masterbatch.
1. Surface Appearance & Gloss Performance
Unfilled Pure Resin Masterbatch
The gloss of finished products completely depends on the resin matrix itself. Polyolefin substrates only deliver medium gloss. For white color masterbatch systems, a high dosage of titanium dioxide is required to achieve ideal hiding power, which directly increases the overall formula cost.
Barium Sulfate Filled Masterbatch
Ultrafine precipitated barium sulfate features a refractive index of 1.64 with excellent light reflection properties. It effectively improves the surface gloss of products and avoids dull or foggy surfaces. In white masterbatch formulas, barium sulfate forms a synergistic hiding effect with titanium dioxide. It can reduce TiO₂ consumption by 10%–20% while maintaining the same whiteness and covering power, realizing optimal cost control.
Physical Comparison Tip: Under the same substrate and processing conditions, panels with barium sulfate present obviously higher gloss than pure resin panels.
2. Density & Special Functional Properties
Pure resin masterbatch has a low density (PE: approx. 0.92 g/cm³, PP: approx. 0.91 g/cm³), which cannot meet the requirements of weight increasing, X-ray opacity, sound insulation and other special functions.
With a high density of 4.3–4.5 g/cm³, barium sulfate can significantly increase product density even at a low addition ratio. It is the preferred functional filler for weighted parts, X-ray opaque medical accessories, and sound insulation & vibration reduction products.
Typical Application Case: Pure TPU samples are completely transparent under X-rays, while TPU modified with 20% barium sulfate presents clear X-ray imaging, which is widely used in medical catheter masterbatch.
3. Mechanical Properties
- Pure Resin Masterbatch: High elongation at break and good toughness, with relatively low flexural modulus and surface hardness.
- Low Dosage (5–10 wt%) Modified Barium Sulfate: Effectively improves the flexural modulus and surface hardness of materials, with a slight increase in tensile strength. Nano-modified barium sulfate can even enhance elongation at break simultaneously.
- High Filling or Unmodified Barium Sulfate: Unactivated barium sulfate is prone to agglomeration, reducing the impact strength and elongation at break, and weakening the toughness of finished products.
Core Key Point: Surface modification of filler is critical. Untreated barium sulfate has poor compatibility with the resin interface, causing agglomeration and deterioration of mechanical properties.
4. Weather Resistance & Chemical Stability
Pure polymer resins are prone to aging and yellowin
