Fiber Densities Measured by Volume Expansion Method.

Abstract

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.