ANALYSIS OF WATER IN OIL-IMPREGNATED KRAFT PAPER AND ITS EFFECT ON CONDUCTIVITY

Oil impregnated paper or polymer film is the main insulating system fo r many kinds of power apparatus. The oil impregnated materials, especi ally oil impregnated kraft paper, include a significant amount of wate r, and this water disturbs the insulating performance of the devices. The amount of water in the materials usually is represented by the dif ference in weight between the normal material and the same material af ter drying. However it is difficult to measure the absolute value of t he water content and to determine the state in which the water exists in the materials. In this study, we examined the IR spectra of water i n oil impregnated kraft paper, because the IR spectrum of the water in dicates not only the amount of water but also its state. It was found that most of the water behaves as liquid water, and some as hydrogen b onded water, interacting with the paper fiber. The de conductivity of the kraft paper depends only on the amount and state of the water asso ciated with it whether or not the paper is impregnated with the oil.