A novel high-speed testing method for dynamic mechanical properties of polymer threads under extreme stretching conditions

The publication presents the results of experimental studies on dynamic stretching multifilament polyamide (PA6) threads with linear densities of 56 and 156 dtex and polyester threads with linear densities of 55, 111, and 167 dtex, using an original, designed, and constructed test stand. This allowed for measurements to be performed at speeds ranging from 10 to 100 m/s and the lengths of the stretched thread sections from 200 to 1000 mm. A strain gauge sensor with a high natural frequency of 11 kHz was used to measure thread forces, and the results were recorded on a computer equipped with a 10 MHz data acquisition card. Analysis of the experimental characteristics showed that increasing the stretching speed decreases the thread forces and strain for the same stretched length. The publication also addresses up the differences between static and dynamic stretching behaviour and the need to relate analyses of textile properties to actual production and operating conditions. In most cases, the analyses concern metrological measurements obtained on classical tensile testing machines at low stretching speeds and often do not reflect the actual conditions of textile use.