Water-based Epoxy Impregnating Varnish Selection Guide

Guangzhou Feisi Waterborne Epoxy Insulating Impregnating Varnish Selection Guide: FS7100 / FS7230 / FS7231 / FS7236 for Precise Winding Insulation Matching

From home appliances to industrial motors: one-stop solution for upgrading winding insulation and helping enterprises efficiently replace solvent-based insulating varnishes with eco-friendly alternatives.

I. Why Waterborne Epoxy Insulating Varnish Is the Inevitable Choice?

Under tightening environmental regulations and rising energy efficiency standards for electrical equipment, traditional solvent-based insulating varnishes are rapidly exiting the market. These products emit high levels of VOCs, are highly flammable, and involve complex process controls, making them unable to meet the mandatory requirements for corporate environmental compliance and workplace safety.

Compared to traditional solvent-based solutions, waterborne epoxy insulation impregnating varnishes offer three irreplaceable advantages:

• Eco-friendly & Safe: Uses water as the dispersion medium to eliminate organic solvents, achieving low VOCs, no irritating odors, and non-flammable/non-explosive properties from the source. Significantly enhances workshop safety standards.

• High process tolerance: Supports immersion, vacuum impregnation, and other application methods; wide curing temperature range (80~130°C) to accommodate diverse production line conditions.

• Superior electrical performance: volume resistivity typically exceeds 1.0×10¹⁰ Ω·m, with dielectric strength of 70~100 MV/m, ensuring long-term stable operation in high-voltage and high-humidity environments.

Guangzhou Feisi Synthetic Materials Co., Ltd. is a leading manufacturer of water-based insulating materials, providing mature, scalable solutions for home appliance motors, industrial motors, and new energy equipment.

II. Four Core Advantages of Guangzhou Feisi Waterborne Epoxy Impregnating Varnish

Frees' Guangzhou single-component water-based epoxy impregnating varnish system requires no on-site mixing—open and use directly. Industry-leading performance across four key metrics:

1. Eco-Compliant Excellence: FS7100 Series VOC content is below 50 g/L, meeting China's latest environmental regulations and passing EU RoHS and REACH compliance checks for export orders.

2. Superior electrical insulation performance: Volume resistivity ≥1.0×10¹⁰ Ω·m; dielectric strength up to 70~100 MV/m. Maintains stable insulation even under harsh conditions such as high temperature and humidity.

3. High process tolerance: single-component system requires no on-site mixing; compatible with dip, vacuum impregnation, and other processes; wide curing temperature range (80~130°C) to suit various production line heating conditions.

4. Stable storage, low management cost. Seal and store below 25°C for up to 90–180 days—far exceeding industry standards—to significantly reduce raw material spoilage and warehouse management costs.

3. Detailed Overview of Four Product Series: Precise Selection by Use Case

To address the diverse needs of various applications in the electrical insulation sector, Guangzhou Feisi has developed a comprehensive product portfolio featuring four series of waterborne epoxy impregnating varnishes: FS7100, FS7230, FS7231, and FS7236.

1. FS7100 Series: The All-in-One Foundation for General and Industrial Applications

Targeted at insulation treatment for small and medium-sized motors, motor windings, transformer coils, and critical power equipment such as generators, distribution transformers, and large industrial motors.

Key Specifications:

• Viscosity: 15±5 S; excellent leveling

• Bonding Strength: ≥120 N

• Dielectric Strength: ≥100 MV/m

• Curing condition: 120130℃ × 120180 min

Features: Moderate viscosity, excellent penetration and filling, superior adhesion after curing. Balances high reliability with cost-effectiveness; the go-to general-purpose model for most motor and transformer production lines.

1. FS7230 Series: The All-Rounder for Home Appliance Motors

Positioned for insulating and impregnating motor windings in home appliances such as fans, washing machines, and air conditioners.

Key Specifications:

• Excellent rust flash resistance

• Volume resistivity remains ≥1.0×10⁸ Ω·m after 2 hours of water immersion

• Wide curing temperature range

Key Features: Offers superior flash rust resistance and moisture protection, effectively mitigating insulation failure risks in appliances exposed to humid or condensing environments while extending motor lifespan.

1. FS7236 Series: The Resilient Guardian for Compressors and Industrial Motors

Targeted for compressors, industrial motors, and other high-vibration, high-humidity harsh environments.

Key Specifications:

• Reinforced resilient formula with superior mechanical stress resistance

• Excellent water resistance, suitable for long-term high-humidity environments

• Curing temperature range: 80~120°C, highly adaptable to processes

Key Features: Enhanced toughness and water resistance effectively prevent insulation cracking caused by high vibration, while a wide curing window reduces the precision requirements for baking equipment.

1. FS7231 Series: The Precision Guardian of High-Frequency Transformers

Designed for impregnation and insulation of high-frequency transformer coils.

Key Specifications:

• No knots, no clogged holes

• Superior penetration and uniform filling

• Immersion for precision electronic components

Key Feature: Engineered for the precise insulation needs of high-frequency transformers to eliminate paint lumps and clogging, ensuring uniform coating in micro-gaps. Prevents component failure due to localized defects.

IV. Quick Product Matrix Selection Guide

Quickly locate the four products by application scenario:

• General Industrial Motors/Transformers → FS7100: High dielectric strength, strong adhesion, and excellent leveling

• Home Appliance Motors (Fans, Washers, AC Units) → FS7230: Excellent anti-flash rust, moisture resistance, and water durability

• Compressor/High-Vibration Industrial Motor → FS7236: Enhanced toughness, mechanical stress resistance, and water resistance

• High-Frequency Transformers/Precision Electronics → FS7231: No paint nodules, no clogged holes, high-penetration filling

Fine-tune specific process parameters based on part size and on-site equipment conditions. Conduct trial runs before mass production.

5. Construction Recommendations and Craft Guidelines (Technical Tips)

1. Material Requirements for Equipment The paint storage tank, circulation piping, and dipping tank must all be made of stainless steel. Rust from iron containers can leach iron ions into the paint, causing emulsion destabilization and resulting in the entire batch being ruined.

2. Temperature Control: Strictly Adhere to Dual-Temperature Limits

• Workpiece Temperature: Cool the workpiece to room temperature before dipping. Never immerse hot workpieces! Excessive heat will raise the paint bath temperature beyond limits, causing skinning or emulsion break.

• Paint temperature: Keep the paint temperature below 30~40℃ during application. Excessively high temperatures can also cause emulsion destabilization.

1. Baking and Dehumidification: Keep the oven outlet clear to ensure rapid moisture removal during curing. Poor dehumidification will directly affect film dryness and substrate adhesion.

6. Standardized Construction Process

All Fidei water-based epoxy insulation dipping varnishes are single-component systems, requiring no on-site mixing. Simply open the bucket and use immediately. Standard four-step process:

Step 1: Workpiece Pre-treatment – Ensure coils are dry, clean, and free from oil or contaminants. Step 2: Impregnation – Perform either standard or continuous dipping for 15 minutes until no more bubbles appear on the liquid surface. Step 3: Drip-off and Drainage – Allow excess varnish to drip until no droplets form, preventing uneven coating due to local buildup. Step 4: Baking and Curing – Set temperature and duration based on product model (e.g., FS7100: recommended 120130°C × 120–180 min). Adjust actual parameters according to workpiece dimensions.

7. Packaging and Storage Standards

Packaging Specifications:

• Standard specifications: 20kg/bucket, 50kg/bucket, 200kg/ buckets, 1000kg/ IBC tanks

• Supports on-demand customization to meet the needs of production lines of any scale.

Storage Conditions:

• Seal and store in a cool, dry place below 25°C

• Avoid direct sunlight and prolonged exposure. Keep away from open flames and heat sources.

• Use promptly after opening. Seal the lid tightly after each use.

Shelf Life:

• 90–180 days from the date of production (subject to individual product labels)

• Stability far exceeds industry averages, effectively reducing warehouse losses.

8. Choose Guangzhou Feisi for peace of mind

Under the "Dual Carbon" goals and smart manufacturing landscape, waterborne epoxy insulating varnish has shifted from an optional choice to a must-have. Guangzhou Feisi leverages technology-driven innovation to deliver high-eco-friendly, high-performance, and highly stable insulation material solutions for home appliances, industrial motors, and new energy equipment.

We offer more than just products—we provide comprehensive application support, from prototype validation to production line commissioning.