Synergistic effect of epoxy resin and silica fume
Epoxy resins are widely used in electronic packaging, coatings, and composites due to their excellent adhesion, chemical resistance, low curing shrinkage, and good electrical insulation properties. However, its lack of heat resistance, high brittleness, and susceptibility to internal stress during the curing process limit its application in high-end scenarios. Silica fume (microsilica), as a functional filler, can significantly optimize the comprehensive performance of epoxy resins through physical filling and chemical modification, becoming one of the key technologies to solve these pain points.
1. Reduce the internal stress of curing reaction and prevent cracking
The addition of silica fume can effectively reduce the exothermic peak temperature in the curing reaction of epoxy resin, thus reducing the internal defects caused by thermal stress. For example, in electronic packaging materials, silica fume by regulating the exothermic rate of the curing reaction, reduce the coefficient of linear expansion and shrinkage of the cured material to avoid micro-cracks caused by thermal stress concentration.
2. Improve mechanical properties and wear resistance
Silica fume particles with high hardness (Mohs hardness 7) and controllable particle size distribution can enhance the tensile strength, compressive strength and abrasion resistance of epoxy resin. Experiments show that after adding silica fume, the abrasion resistance of epoxy resin can be improved by 0.5-2.5 times, which is especially suitable for floor coatings, industrial molds and other scenarios that require high mechanical strength.
3. Optimization of flame retardant and high temperature resistance performance
The flame retardant property of epoxy resin can be significantly improved by introducing silicon element. silica fume forms a stable silica protective layer at high temperatures, insulating oxygen and retarding combustion. For example, phosphorus-silica-nitrogen synergistic flame retardant system can make the epoxy resin reach the non-combustible standard, while maintaining its original dielectric properties.
The core application areas of silica fume in epoxy resin
1. Electronic packaging and semiconductor materials
- Insulation and encapsulation: electronic grade silica fume (SiO₂ purity > 99%) used in integrated circuit plastic sealing material, can reduce the viscosity of the mixed system, enhance the filling density, reduce the thermal expansion coefficient difference caused by the failure of the encapsulation.
- Thermal conductivity and heat dissipation: ultra-fine silica fume improves the thermal conductivity of epoxy resin by optimizing the thermal conductivity path, which is suitable for high-power LED encapsulation and heat dissipation substrates.
2. High performance coatings and adhesives
- Anti-corrosion coatings: The acid and alkali resistance and chemical stability of silica fume make it a key filler for heavy anti-corrosion coatings for ships, bridges, etc., extending the coating life by more than 30%.
- Floor Coating: Through the grade optimization of silica fume, the abrasion resistance and impact resistance of epoxy flooring are significantly improved, while reducing the amount of resin and saving costs.
3. Composite materials and aerospace
- Lightweight structural materials: silicone powder reinforced epoxy resin composites are used for aircraft components, both high strength and low density, and high temperature resistance to meet aviation standards.
The technical advantages of HSA silica fume and selection recommendations
1. Technical Advantage: Customized silica fume Solutions for Industrial Scenarios
HSA, as a leading enterprise in the field of microsilica powder in China, relying on the advanced encryption process and whiteness control technology, has launched the series of fully Densified/Undensified microsilica (SiO₂ purity 85%-99%) and high whiteness microsilica powder, which can comprehensively satisfy the demanding needs of concrete, refractory materials and other industries:
Encryption process innovation
- Densified silica fume: the physical compression technology makes the stacking density increase to 650-800kg/m³, with excellent fluidity, greatly reducing the transportation cost and on-site dust, suitable for automated production lines.
- Undensified silica fume: density 300-500kg/m³, high dispersibility and storage stability, suitable for manual feeding and small mixing equipment.
Characteristics of white silica fume
- Whiteness value ≥92% (ISO brightness standard), avoiding the interference of traditional grey silica fume on the color of finished products, widely used in decorative concrete, white refractory castables and high-end ceramic products.
- Metal impurities are removed by acid and alkali washing process, and Fe₂O₃ content can be controlled below 0.15%, which guarantees chemical stability in high temperature scenarios.
Multi-functional grading system
- Provide a full range of products from regular particle size (0.1-0.3μm) to ultra-fine grade (50-100nm), suitable for shotcrete, low cement refractory castables and other needs for different densities.
- We support surface modification (e.g. hydrophobic treatment) to improve compatibility with organic/inorganic substrates.
2. Selection Guide: Accurately Match Industry Demands
| Fields of application | Recommended products | Core performance indicators | Typical scenario |
|---|---|---|---|
| High-performance concrete | Densified silica fume (SiO₂≥85%) | The specific surface area is 15-25m²/g, and the water requirement ratio is ≤105% | Super high-rise pumping concrete, anti-corrosion flooring |
| Refractory materials | Undensified silica fume (SiO₂≥90%) | Median particle size0.2μm，Al₂O₃≤1.2% | Ladle castable, hot metal ditch refractory lining |
| White building materials | White silica fume (SiO₂≥98%) | Whiteness≥92%，Cl⁻ content≤0.02% | Art decorative concrete, precision casting coatings |
| Special Engineering | Ultrafine Densified Silica Fume (SiO₂≥99%) | Particle size≤ 100nm, loss on ignition≤ 1.5% | Nuclear power plant shielding concrete, aerospace high-temperature resistant coating |
About HSA: Leading the technological innovation of micro silica
At Henan Superior Abrasives (HSA), we are proud to be one of China’s largest suppliers of silica fume, offering high-quality products that meet international standards. Our silica fume is widely used in a range of industries, including construction, manufacturing, and aerospace. If you are looking to enhance the performance of your epoxy resins or other materials, we invite you to explore our products and contact us for more information.
Our commitment:
- Technical customization: Provide personalized solutions for particle size, purity, and surface modification according to customers’ needs.
- Stable supply: annual production capacity exceeds 500,000 tons, guaranteeing delivery of large-scale orders.
- Sustainable development: Adopt green production process, the recycling rate of silica fume reaches more than 95%.
Contact Us
Whether you’re a coatings manufacturer, an electronics packaging company, or a composites developer, HSA’s silica fume solutions will give your products higher performance and cost advantages. Contact us today for a free sample and technical consultation!
