LE-8416F Epoxy Casting Resin with 35-40kV/mm Dielectric Strength for APG Process and 0.6-0.8% Cure Shrinkage

Product Introduction

LE-8416F is a premium two-component epoxy resin system specifically engineered for medium and high voltage transformer casting and insulation applications. Based on a modified bisphenol-A epoxy resin formulation with a liquid carboxylic anhydride hardener, this system delivers exceptional dielectric strength exceeding 35kV/mm, making it the ideal choice for dry-type transformers, voltage transformers, current transformers, and other critical electrical insulation components operating at 10-66kV. The resin's low viscosity and optimized gel time ensure outstanding APG process compatibility, enabling efficient Automatic Pressure Gelation and conventional vacuum casting production. With ultra-low cure shrinkage below 0.8%, LE-8416F guarantees dimensional precision and minimal internal stress in finished castings.

Key Features & Characteristics

Superior Dielectric Strength for High Voltage Reliability

LE-8416F achieves a dielectric strength of 35-40kV/mm (ASTM D149), providing industry-leading electrical insulation performance. This exceptional dielectric strength ensures reliable operation in medium and high voltage transformers, current transformers, and voltage transformers, preventing partial discharge and electrical breakdown even under demanding operational conditions. The resin's high insulation resistance and low dielectric loss factor contribute to long-term electrical stability.

Optimized APG Process Compatibility

Formulated with precisely controlled reactivity and viscosity, LE-8416F exhibits superior APG process compatibility. The system features an adjustable gel time of 8-25 minutes at molding temperature, enabling efficient automatic pressure gelation processing. Its excellent low viscosity of 800-1500 mPa·s at 25°C ensures complete mold filling and thorough impregnation of embedded components, reducing rejection rates and improving production yield for transformer manufacturers.

Outstanding Flame Retardancy for Safety Compliance

Safety is paramount in electrical installations. LE-8416F incorporates an advanced flame retardant formulation achieving HB rating (UL 94, 4mm), with self-extinguishing properties that prevent flame propagation. This flame retardancy meets international safety standards for electrical equipment, providing peace of mind for transformer manufacturers and end-users in residential, commercial, and industrial installations where fire safety regulations are stringent.

Ultra-Low Shrinkage for Dimensional Precision

With low shrinkage of just 0.6-0.8% during cure (ISO 178), LE-8416F ensures exceptional dimensional stability in finished components. This minimal low shrinkage characteristic prevents cracking, void formation, and internal stress buildup, which are critical factors in maintaining the long-term reliability of transformer bushings, insulators, and embedded pole components. The result is consistently high-quality castings with tight dimensional tolerances.

Excellent Mechanical Strength and Thermal Performance

LE-8416F delivers outstanding mechanical strength with flexural strength of 110-140 N/mm² (ISO 178) and compressive strength of 150-200 N/mm² (ISO 604). The cured system achieves a glass transition temperature (Tg) of 100-120°C (ISO 11357-2), ensuring reliable performance at elevated operating temperatures. Impact strength of 10-18 kJ/m² (ISO 179) provides toughness against mechanical shock during transport and installation, making this resin a robust solution for demanding transformer applications.

Why Choose Us

• Industry-Leading Dielectric Strength: Our LE-8416F system delivers superior electrical insulation with 35-40kV/mm dielectric strength, exceeding standard industry requirements and providing an extra safety margin for high voltage applications.
• Proven APG Process Expertise: With decades of formulation experience, our resin systems are precisely optimized for APG process compatibility, reducing cycle times and improving production efficiency for transformer manufacturers worldwide.
• Comprehensive Quality Control: Every batch undergoes rigorous testing including dielectric strength measurement, viscosity profiling, gel time verification, and mechanical strength validation per ISO standards.
• Technical Support Excellence: Our engineering team provides on-site processing guidance, formulation customization, and troubleshooting support to ensure seamless integration into your production line.
• Global Certifications: ISO 9001:2015 certified manufacturing, with products meeting REACH and RoHS compliance requirements for international markets.

Technical Specifications

Frequently Asked Questions

Q1: What voltage range is LE-8416F suitable for?

LE-8416F is designed for medium and high voltage applications up to 66kV. Its exceptional dielectric strength of 35-40kV/mm provides reliable insulation for dry-type transformers, voltage transformers, and current transformers operating in 10-66kV power distribution networks.

Q2: Can this resin be used with APG (Automatic Pressure Gelation) machines?

Yes, LE-8416F is specifically optimized for APG process compatibility. Its controlled viscosity and adjustable gel time (8-25 minutes) make it ideal for both automatic pressure gelation and conventional vacuum casting processes. The low shrinkage characteristic ensures excellent mold release and dimensional accuracy.

Q3: What is the recommended silica filler loading ratio?

We recommend 300-400 pbw of silica flour (SiO₂) per 100 pbw of resin and 100 pbw of hardener. This filler ratio optimizes mechanical strength, reduces low shrinkage, and enhances thermal conductivity while maintaining excellent dielectric strength properties.

Q4: Is LE-8416F flame retardant?

Yes, LE-8416F features inherent flame retardant properties achieving HB classification per UL 94 (4mm thickness). The flame retardancy formulation meets safety requirements for indoor electrical equipment, providing self-extinguishing behavior that prevents flame spread in the event of electrical faults.

Q5: Do you provide technical support for process optimization?

Absolutely. Our engineering team offers comprehensive application support including viscosity profiling, gel time adjustment, and on-site APG process compatibility optimization. We can customize the formulation to match your specific production parameters, mold design, and cycle time requirements.