A study of thermal deterioration of kraft pulps using a mass spectrometer

As thermal deterioration of electrical insulating materials is directly connected with their lives it has been an important problem since electric machines and apparatuses were put to practical use. Nevertheless, a thorough study has not been made on the subject because quite a long time is required for testing the lives of the materials and also because numberless combinations and many working conditions of materials must be considered in order to get sufficient data concerning the problem. Moreover new insulating materials are rapidly appearing and it has become necessary for us to know their deterioration properties. Consequently, it is necessary to find a test method which will enable us to know these characteristics within a short period of time. Accordingly the authors intended to find the degradation of some kind of insulating materials with a mass spectrometer as it was impossible to detect a large quantity of deterioration products by the apparatus in general use.1 Kraft pulps were taken as samples first. In analyzing thermally generated gases from the samples, fundamental data were obtained in a short time by which thermal endurance of the materials could be concluded.