Non-contact Ultrasound Method of Thread Tension Determination for Light Industry Machinery

It has been established that with the help of a pulsed ultrasonic signal of complex shape, it is possible to determine the tension of a filament with a high linear density in a special waveguide with a rectangular crosssection. It has been proved that the amplitude ratios of ultrasonic waves that interact with different textile filaments are influenced by their linear density, the angle between the passage direction of part of the waves enveloping the fibers in the middle and the surface of these fibers, as well as the angle between the direction of wave propagation enveloping the thread itself from the outside, and the surface of the whole material. It should be noted that the corresponding bypass angles of the ultrasonic waves of the textile depend on the material porosity, frequency of the ultrasonic waves, and their power. To enable non-contact control of the change in the tension of the thread branch, it is advisable to use a pulsed ultrasonic signal with two different peaks of the waves, amplitudes, which are adjusted to the linear density of the thread and its conditional radius. Additionally, the use of this method will provide operational technological control in the production of textile fabrics