A New Transformer Insulation

Abstract

A chemical modification of cellulose has resulted in a new transformer insulation called Thermecel. Aging tests made in oil under carefully controlled conditions have shown TherMEcel to have much greater thermal stability than electrical grade kraft paper. The necessity of evaluating absolute strength, as well as the retention of several physical properties during aging, is emphasized. Toughness is suggested as a good evaluation parameter. TherMEcel can be produced as tape, paper, and board.