Talc (Laminar, d50 10µm, Composites Grade)
Key Features
- High aspect ratio laminar morphology improves stiffness and dimensional stability
- Reduces resin shrinkage in SMC/BMC parts for dimensional precision
- Inherent surface hydrophobicity improves moisture resistance vs. CaCO3
- Soft lubricious character improves mold release in compression molding
- Compatible with UPR, epoxy, and SMC/BMC resin systems
Talc is a naturally occurring hydrated magnesium silicate (Mg₃Si₄O₁₀(OH)₂) characterized by its unique lamellar (platy) crystal structure. This composites-grade talc features a median particle size of 10 µm with a high aspect ratio of approximately 10:1–20:1, providing significantly better reinforcing effect than isometric fillers at equivalent loading levels.
The platy morphology of talc aligns preferentially parallel to the part surface during processing, creating a reinforcing layer structure that improves stiffness (flexural modulus), reduces resin shrinkage, and enhances dimensional stability. This makes talc particularly valuable in SMC/BMC compounds for automotive body panels, where dimensional precision is critical. Talc also improves the surface quality of molded composites by filling micro-voids and creating a smooth matrix for topcoat adhesion.
Talc's natural hydrophobic surface (lubricious, soft-feel characteristic) provides inherent water resistance and reduces the tendency to absorb moisture compared to CaCO3. Its chemical inertness and white-to-light-gray appearance make it compatible with natural and colored composite systems. Typical loadings are 20–80 phr in UPR systems, with higher loadings (100+ phr) feasible in heavily filled SMC compounds. The inherent lubricity of talc also improves mold release in compression molding applications.
Specifications
| Parameter | Value |
|---|---|
| Appearance | White to light gray powder |
| MgO content | 31–32% |
| Aspect ratio | 10:1 – 20:1 (laminar) |
| SiO₂ content | 59–60% |
| BET surface area | 5–10 m²/g |
| Moisture content | ≤ 0.5% |
| Whiteness (R457) | ≥ 85% |
| Bulk density (tapped) | 0.3–0.5 g/cm³ |
| Loss on ignition (1000°C) | 4.5–5.5% |
| Median particle size (d50) | 10 µm |
Applications
FAQ
Talc platelets orient parallel to the part surface during SMC flow and compression, creating an anisotropic layer structure. This reduces in-plane shrinkage and differential thermal expansion, minimizing post-mold warpage. When combined with LPA (low profile additives), talc-filled SMC achieves Class A surface finish suitable for automotive exterior panels. Typical loading 40–80 phr.
Direct Contact
💬WhatsApp +86 156 3910 0440Telegram +86 156 3910 0440✉️[email protected]Reply within 24 hours
Related Products
Ground Calcium Carbonate (Fine, d50 5µm)
CAS 471-34-1
Fine particle size for improved surface quality versus coarse grades
Calcined Kaolin (Anhydrous, d50 2µm)
CAS 1332-58-7
Anhydrous (LOI <0.5%) — suitable for moisture-sensitive resin systems
Muscovite Mica (Flake, d50 120µm)
CAS 12001-26-2
Extremely high aspect ratio (>30:1) for superior barrier and reinforcing properties
Wollastonite Short Fiber (L/D 10:1)
CAS 13983-17-0
L/D 10:1 acicular morphology provides fiber-like mechanical reinforcement