Introduction
Silica powders are classified into crystalline, fused and spherical types based on manufacturing process and particle morphology. They differ significantly in process, performance and applications. Understanding these differences is key to correct selection.
Core Differences Between the Three Types
1. Manufacturing Process
Crystalline silica is produced by directly grinding and classifying natural quartz - simple and cost-effective. Fused silica is made by melting high-purity quartz at high temperature then grinding, forming an amorphous structure. Spherical silica is spheroidized via flame or plasma method, producing spherical particles.
2. Key Performance
- Crystalline silica: High hardness, stable chemistry, relatively higher CTE
- Fused silica: Low CTE (approx. 0.5×10⁻⁶/K), excellent electrical insulation, low-alpha grades available
- Spherical silica: Sphericity ≥95%, good flowability, high filling rate, low viscosity
3. Typical Applications
- Crystalline silica: Coatings, rubber, plastics, general electronic packaging
- Fused silica: Epoxy molding compounds, copper clad laminates, precision casting - high-end electronics
- Spherical silica: Advanced packaging, high-fill EMC, thermal interface materials
How to Choose
For general industrial applications, crystalline silica offers the best value. For electronic packaging and low-expansion requirements, choose fused silica. For high filling, low viscosity and advanced packaging, choose spherical silica.
Maylynk offers the full range of all three silica types, with samples and technical comparisons available. Contact us for a consultation.