Abstract
In order to clarify the vacuum drying process of insulation paper layer, permeability of water vapor at 110°C, 4 to 0.1mmHg ; and of air at room temperature, atmospheric pressure to 10 mmHg are measured. The results are ;
(1) Air permeation below the order 10 mmHg is of molecular flow and is independent of mean pressure.
(2) The equivalent pore radius of measured paper is about 3 microns.
(3) Water vapor permeation in vacuum drying condition is also considered to be molecular flow and permeability value coincides with that calculated from air permeability.
These informations are useful in analyzing a drying process of paper insulation layer.
