EXPERIMENTAL STUDY ON THE FRICTION CHARACTERISTICS OF COTTON FABRICS WITH CLOTH TWILL 3/1 BEFORE AND AFTER FINISHING

This research shows some of the functional characteristics of the cotton fabrics all in the same cloth twill 3/1 in different direction of the cloth and under different pressure. The measurements are conducted according to the standard BDS EN ISO 8295:2006 using -meter MXD-02 made by Labthink, China. The tester allows the determination of the static and the dynamic coefficients of friction (COF). The tests are performed for both fabric sides (face and reverse), in different fabric directions, and under different pressure (200, 300 and 400 g). The speed of sliding has been constant -100 mm/min. Formulas for frictional characteristics specialized for fabrics have been used for the precise determination of the fraction behavior of the textile products – friction index n, friction parameter C and friction factor R. The connection between the friction force and the normal pressure is transformed to logarithmic relation: i=1, 2,…m; B – contact area (m2); C – friction parameter [Ра1-n]; n – friction index (without dimension); N – normal pressure [N]; F – friction force [N]; m – number of conducted examinations. The friction index n and the friction parameter C are calculated from the coefficients of the linear regression equation. The friction parameter and the friction index are used for the determination of the friction factor R. Conducted examinations show the influence of the pressure on the friction characteristics of fabrics with the same composition (cotton), but made from yarns with different linear densities. The values of the friction characteristics depend also on the changing of the actual contact area which varies in the different fabric directions. The actual contact area is growing with the increase of the pressure that leads to the increase of the coefficient of friction in neutral state (at rest) and the coefficient of friction when sliding.