Fillers, also known as extenders, are essential components in the plastic production industry. They enhance physical and chemical properties while reducing manufacturing costs. This article provides a detailed analysis of popular fillers like talc, calcium carbonate, titanium dioxide, barytes, silica, and kaolin. It also includes a comparison table and suggestions for selecting the right filler for specific plastic types.
WHAT ARE FILLERS IN PLASTICS?
Fillers are mineral or synthetic compounds added to the plastic matrix. They increase rigidity, heat resistance, and improve processability. However, the choice of filler depends on the plastic type, such as PP, PVC, PE, or ABS. Each filler has unique characteristics, tailored to specific production goals.
DETAILED ANALYSIS OF POPULAR FILLER TYPES
Talc
Talc, with the formula Mg₃Si₄O₁₀(OH)₂, is mined from natural minerals. It features a whiteness of 87–95%, particle size of 1250–3000 mesh, pH of 8.0–9.5, and low moisture content (~0.3%). It absorbs DOP at about 48g/100g, making it suitable for various plastics.
This filler enhances rigidity, heat resistance, and gloss in PP, PVC, and ABS plastics. Talc is often selected for plastic products requiring high mechanical strength and thermal stability.
Check out the talc powder products currently distributed by Vichem
Calcium Carbonate (CaCO₃)
Calcium carbonate is produced from crushed limestone or precipitation. It stands out for its low cost, ~95% whiteness, and easy dispersibility. It is commonly used in PE, PP, and PVC to reduce costs and increase rigidity, but it has limitations in mechanical improvements. This is the most popular filler due to its abundant supply and economic pricing.
Titanium Dioxide (TiO₂)
TiO₂ is produced via the chloride or sulfate process. This filler offers strong opacity, UV resistance, and bright white coloring. It is suitable for engineering plastics and white masterbatches. However, it has a high cost and requires good dispersion. Thanks to its color durability, TiO₂ is preferred for outdoor products.
Check out the TiO₂ powder products currently distributed by Vichem
Barytes (BaSO₄)
Barytes (BaSO₄) has a high specific gravity and excellent chemical resistance. This filler is typically applied in rigid PVC, flame-retardant plastics, and construction materials. It increases density, gloss, and thermal stability, though it is expensive and challenging to disperse in some plastic systems. Additionally, BaSO₄ supports enhanced flame retardancy in products.
Silica (SiO₂)
Silica (SiO₂) in precipitated or gel form features ultra-fine particles and large surface area, ideal for engineering plastics, silicones, and coatings. It improves mechanical properties, controls viscosity, and prevents sagging, but it is costly and requires modern dispersion equipment. Silica is often used in applications demanding tensile strength and abrasion resistance.
Kaolin (Clay)
Kaolin (Al₂Si₂O₅(OH)₄) is an economical filler with ultra-fine particles and off-white color, commonly used in PVC, PE, and extruded plastics. Its advantages include low cost, increased rigidity, and improved product shape. However, it offers limited mechanical enhancements and lower whiteness than TiO₂. Due to its stability, kaolin is considered a cost-effective solution for many common applications.
COMPARISON TABLE OF FILLER TYPES
| Filler Name | Origin/Main Compound | Key Properties | Main applications | Advantages | Limitations |
| Talc | Mg3Si4O10(OH)2 | Whiteness: 87–95%, particle size 1250–3000 mesh, pH: 8.0–9.5, DOP: 48g/100g, moisture ~0.3% | PP, PE, PVC, ABS, PA, TPE | Increases rigidity, heat resistance, impact resistance, improves gloss | Reduces toughness if unevenly distributed; higher cost than CaCO₃ |
| Calcium Carbonate (CaCO3) | Crushed/Precipitated Limestone | Whiteness ~95%, particle size 800–2500 mesh, easy dispersion, low cost | PP, PE, PVC, PET, HDPE, LDPE | Low cost, increases rigidity, reduces expenses | Limited mechanical enhancement; prone to precipitation if poorly handled |
| Titanium Dioxide (TiO2) | Chloride/Sulfate Process | High whiteness, strong opacity, UV resistance, types R-902, R-2160, R-95 | Engineering plastics, coatings, white masterbatches | Excellent opacity, optical and mechanical stability | High cost; requires good dispersion to avoid weaknesses |
| Barytes (BaSO4) | Natural Barite Mineral | Specific gravity 4.5 g/cm³, good chemical resistance | Rigid PVC, flame-retardant plastics, pipes | Increases density, gloss, acid resistance, thermal stability | Higher cost than CaCO₃; difficult dispersion in some plastic systems |
| Silica (SiO2) | Precipitated/Gel Silica | Large surface area, ultra-fine particles, high absorption | Engineering plastics, plastic coatings, silicones | Enhances mechanical properties, controls viscosity, prevents sagging | High cost; requires advanced dispersion equipment |
| Kaolin (Clay) | Al₂Si₂O₅(OH)₄ | Ultra-fine particles, off-white color | Extruded plastics, PVC, PE | Low cost, increases rigidity, improves product shape | Lower whiteness than TiO₂; limited mechanical improvements |
GUIDE TO SELECTING THE RIGHT FILLER
The selection of fillers depends on production goals and plastic type. Here are specific suggestions:
- For increased rigidity, heat resistance, and gloss: Talc is the top choice, suitable for PP, PVC, ABS.
- For cost reduction while maintaining processability: CaCO₃ is ideal for PE, HDPE, LDPE.
- For enhanced whiteness, opacity, and UV resistance: TiO₂ is suitable for engineering plastics and white masterbatches.
- For increased density and chemical resistance: Barytes works well for rigid PVC and construction materials.
Additionally, ensure proper filler dispersion control. Otherwise, the product may lose durability or develop defects.
NOTES WHEN USING FILLERS IN PLASTICS
In the process of using fillers, the most important aspect is ensuring uniform dispersion. Poor distribution can lead to defects, reduced durability, and aesthetic issues in the product. Furthermore, businesses should control filler quality to avoid impurities that affect plastic properties.
Additionally, select reputable suppliers to ensure production stability. Testing fillers on a small scale before mass production is also essential. This allows businesses to accurately evaluate compatibility and economic efficiency before widespread application.
VICHEM – AUTHORIZED DISTRIBUTOR OF STANDARD CHEMICAL ADDITIVES IN VIETNAM
Vichem is an authorized distributor of chemical additives in Vietnam, providing full information in compliance with legal regulations. We not only supply high-quality products but also offer international-standard after-sales services. Our services include:
- Technical Consultation: Assisting customers in selecting suitable product samples for their intended use.
- Color Matching Testing: Vichem’s team of experts conducts color matching tests to ensure results meet design standards.
- Application Support: Accompanying customers in integrating products into production lines, ensuring optimal performance.
For more information about our products, please contact us through the following channels:
📞 Hotline: 08 1790 1790
📧 Email: contact@vichem.vn
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