Low Viscosity Flame Retardant Epoxy for Void-Free Transformer Coil Impregnation

LE-9204/LH-9204: UL 94 V-0 Low-Viscosity Epoxy for Transformer Coil Impregnation & Bushings

Product Overview

LE-9204/LH-9204 is a low-viscosity, flame-retardant epoxy system engineered for void-free impregnation of transformer coils and high-voltage bushings. Featuring UL 94 V-0 certification and exceptional flow characteristics, it penetrates complex winding structures to eliminate air pockets, prevent partial discharge, and enhance dielectric strength. Ideal for VPI processes, APG molding, or vacuum casting of dry-type transformers, switchgear, and indoor insulation components up to 40.5 kV.

Key Features & Benefits

Applications

• Dry-type transformers: Coil impregnation and encapsulation

• Medium-voltage switchgear (up to 40.5 kV)

• Bushings and insulators for indoor applications

• Sensor coils and reactor windings

• PCB insulation barriers

Technical Formulation

Cured Properties:

• Viscosity (mixed): <500 mPa·s (enables deep impregnation)

• UL 94 Rating: V-0

• Comparative Tracking Index: >600 V

• Dielectric Strength: >18 kV/mm

• Thermal Shock Resistance: Passes IEC 60137 cycling tests

Processing Methods

1. Vacuum Pressure Impregnation (VPI):

   • Optimal for transformer coils – ensures void-free penetration

2. Automatic Pressure Gelation (APG):

   • High-volume production of bushings/insulators

3. Vacuum Gravity Casting:

   • Bubble-free encapsulation for complex geometries

Why Choose This System?

• Void Elimination: Ultra-low viscosity removes air pockets in windings

• Fire Safety: Critical UL 94 V-0 rating for indoor electrical equipment

• Flexibility Control: Tune toughness with LF-630 flexibilizer

• Accelerated Curing: LZ-622 enables rapid production cycles

• Industrial Compliance: Meets IEEE C57.12.01 for dry-type transformers

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Shanghai Wenyou Industry Co., Ltd.mainly engaged in the advanced materialsof MV and HV insulation products for indoorand outdoor use, both suitable for APG andvacuum casting.

Our wide range of products includes epoxy resin, flame retardant resin, curing agents, outdoor modifiers, toughening agents, epoxy paste, demoulding agents, and fillers.

We have obtained ISO9001, ISO14001, SGS, and UL certifications, and our products comply with ROHS and REACH safety regulations.

Our high-quality products are used in high voltage electrical insulation applications and are exported globally. We are committed to providing stable products and excellent service to the global electricity industry.

High Quality Electrical Raw Materials
Epoxy resin

Release agent

Silica powder
Hardener
Color paste
Flexibilizer