Triboelectric charges on textiles dissipate through a charge conduction mechanism and also by accompanying water molecules evaporating into air. The latter dissipation is less extensive than the former, but can be measured quantitatively under highly insulated experimental conditions. Rate constants of charge dissipation into the air at 20°C have been reported as a function of the ambient humidity and water content of fabrics. In this study, the rate constants are analyzed at temperatures above or below 20°C. Two kinds of water molecules, free and bound, are known to be present in the textile surface from charge dissipation analysis. Though free water is involved in atmospheric charge dissipation, the condition of water molecules in the fibers cannot be classified so simply. Rate constants of charge dissipation depend on the ambient absolute humidity and water content of sample fabrics for all the temperatures of these experiments.

: Deaerated water is used in many industrial fields because of its high permeable property. We proposed the reason for this, as being the ability to dissolve the gas trapped in tiny narrow voids on textile surfaces. This mechanism was confirmed by density measurement using a density gradient column of aqueous salt solution.

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Solid density has been measured using various methods, among which the volume expansion method is rather simple in principle. It has been extensively used for solid powder samples, but only for few polymer sam ples. We tried to use this method to measure the density of various dried polymer samples using helium and ni trogen as measuring gases. The densities obtained were comparable with those found by other methods, Consider ing the effect of the measuring gas size, the polymer microstructure is discussed based on the observed density of textile fibers. The density of humid samples was calculated to be much larger than that of dried samples. Though the effect of water molecules on the density value could not be clearly explained, it is surmised to be the reason for the volume expansion method not being used for density measurement of polymeric materials.