Polymer fibre and cellulose composite paper with starch binder for electrical insulation

Abstract

As per the demand of power transmission systems the life of transformer depends upon the insulating material used. The most important insulating materials of optimum dielectric strength properties that have been used in large high-voltage transformers through almost a century are the oil impregnated, cellulose-based products: primarily paper and pressboard. The chief disadvantage of cellulosic material for electrical use is that it is hygroscopic in nature and needs to be processed and maintained dry. For power transformers the process is quite elaborate and time consuming. To overcome this limitation, a new area to look forward to is blending of cellulose fibers with synthetic fibers. The most important property of these materials is their high thermal stability. Their dielectric strength is excellent, being above that of Kraft paper, and they retain this property for a sustained period even at high temperature for short periods of time. This work discusses the production of electrical grade composite paper from Kraft pulp, synthetic fibers and cationic starch as binder. The insulation paper produced by blending Kraft pulp with synthetic fibers, polyethylene terepthalate has good mechanical properties making it useful for electrical insulation in transformers.