A decade of vacuum pressure impregnation

A Manufacturer of Electric Motors or a Sevice Shop is faced with a major investment in capital equipment and tooling to produce an insulation system for form wound stators which will resist severe moisture and chemical contamination. During the 1960´s, Vacuum Pressure Impregnation {VPI) using 100% solid resins was a new process being introduced to the industry by manufacturers of large rotating apparatus. Resin rich “B” stage tapes and wrappers were the forerunners to achieve impregnation of high voltage insulation systems. This paper will discuss over 10 years of VPI and how each system has a recognized application in which it can excel.