Process Overview

Vacuum Pressure Impregnation (VPI) equipment is designed for the deep and uniform impregnation of electrical windings, coils, and insulating components with varnishes, resins, or oils. The process begins by creating a vacuum environment to remove trapped air and moisture from porous materials. After vacuuming, a controlled pressure cycle forces the impregnating fluid eep into the structure, ensuring complete saturation and superior insulation performance. The system typically consists of a vacuum chamber, resin storage tank, vacuum and pressure pumps, and an automated control panel for process management.

The VPI process improves the thermal, electrical, and mechanical performance of components while extending their lifespan. Advanced VPI systems can be fully automated, providing recipe-based controls, data logging, safety interlocks, and precise monitoring of vacuum levels, pressure cycles, and fluid viscosity

Applications

• Electrical Coil Manufacturing: Impregnation of stator coils, rotors, transformers, and inductors in motors and generators to enhance insulation and mechanical strengths
• High-Voltage Equipment: Varnishing of CT/PT coils, dry-type transformers, and other critical components for moisture resistance and thermal stabilit
• Railways and Defense: Impregnation of windings and assemblies exposed to harsh environmental conditions
• Automotive Industry: Resin impregnation of e-mobility motor stators and high-speed rotating components
• Aerospace Sector: Ensuring high-reliability insulation of avionics and propulsion system coils
• Aftermarket Services: Used in repair and rewinding workshops for reconditioning of motors and electrical equipment