Electro-Conductivity of Textile Fibres

Abstract

The method of determining the electro-conductivity of the textile fibres:and the influences of the treatments on the electro-conductivity of silk have been investigated with the following results.
(1) The electro-conductivity of textile fibres can be determined comparingly by the measurement of a constant electric quantity which is charged in the quadrant electrometer, in the length of time which is needed to discharge it through the test piece of the textile fibre.
(2) The electro-conductivity of raw silk which is stored in places of different moisture and temperature for two years (temp. 5_??_30°C, relative humidity 40_??_90%) can not be distinguished.
(3) The electro-conductivity of the rayon is generally larger than that of the natural silk. Among the rayons, the electro-conductivity of acetate silk is much less than that of the others.
(4) When raw silk is degummed off, the electro-conductivity of it decreases. The electro-conductivity of the scoured silk by means of soap or free caustic soda solution is greater than that of the silk scoured by enzyme such as pancreatin, therefore, if one wishes to get silk of high electric insulation, it is preferable to scoure it by enzyme.
(5) The electro-conductivity of the scoured silk by means of water of high temperature and pressure (over 121°C, two atmospheric press.) is greater than that of the silk scoured by soap or enzyme on be-half of its destruction of fibroin by the treatment under high temp. and pressure.
(6) When the scoured silk by means of soap solution is treated by NaOH of different concen-tration, the electro-conductivity of these silks differs, that is, the electro-conductivity of the silk treated by the more concentrated NaOH, is greater than that of the less concentration. The reason of this does not depend only on the destruction of the fibroin, but is much influenced by the sodium combined with it. This conclusion comes from the facts that. a) When the concen-tration of NaOH is very low (N/400) the strength and elongation of the treated silk is not decreased, while the electro-conductivity of it is increased compared with that of the untreated. b) Furthermore, when the `treated silks with NaOH are immerced into a diluted sulphuric acid the electro-conductivity of the sulphuric acid is decreased according to the degree of concentration of NaOH which is used to treat the silk, that is, the more the sodium combined with the silk fibre the greater its power of decreasing the electro-conduc-tivity of the sulphuric acid when the silk is immerced into it.
(7) When silk is weighted by tin-salt, the electro-conductivity of it is increased according to its degree of weighting. This increase of electro-conductivity is not caused by the destruction of the fibre, but by the weighted salt, because the strength and elongation of the silk (at the course of weighting) is increased to some extent by the weighting, that is to say, the destruction of the silk by weighting must occur in the storage. From this result the announcement “The tin-weighting of the silk will make it less liable to become dirty.” seems to be reasonable.