Bulletin of
Vitebsk State
Technological
University

Abstract

The quality improvement of blended textiles is an urgent task, because when they are developed from the blends of fibers that often have different natures, and, accordingly, physical and mechanical properties, it is very important to achieve uniformity of the manufactured products in composition and characteristics. To date, existing methods for determining the blending irregularity of materials are quite labor-intensive. Devices whose operating principle is based on the use of the capacitive method, designed to determine the unevenness of linear density, do not allow for assessing the blending irregularity of heterogeneous fibrous products. Until now, the capacitive method has not been used to assess the unevenness of mixing.

The aim of the work is to experimentally confirm the use of the capacitive method for assessing the irregularity of fibers blending in heterogeneous textiles. During testing of cotton and polyester fiber samples on the immittance meter MNIPI E7-20 in the frequency range from 2 to 640 kHz with a nominal mass of 0.3, 0.5 and 0.7 g, it was found that the value of the capacitance decreases with increasing frequency and rises with increasing sample mass, which is confirmed by high values of the correlation coefficient. Based on the experimental data a mathematical model is proposed that describes the influence of capacitor frequency on the ratios of capacitance values at different frequencies for different types of fibers excluding the capacitance determined in the absence of material in it. Frequency ranges are identified in which, with the developed capacitor design, the mass of the fiber sample does not have a significant effect on the ratio of signals obtained for cotton and polyester fiber.

Deviations in the of results of repeated experiment data from calculations results according to the proposed model do not exceed 10 %. According to the proposed model, at high frequency, the influence of the kind of fibers will be significantly reduced; the signal ratio tends to unity. It is the differences in the signal ratio at different frequencies with different sample masses that are planned to be used to develop a mathematical apparatus for determining the irregularity of fiber blending in heterogeneous textiles.

Rationale for using the capacity method to assess the blending irregularity of heterogeneous textiles