The Effect of Torsion on the Mechanical Properties of Reinforced Yarn

The widespread introduction of the proposed technology will make it possible to organize the import of substitute fabrics in the republic, to provide various sectors of the national economy with high-quality, cheap products while solving the problem of utilizing indirect waste of natural and chemical fibers in the textile industry. Ключевые слова: Сырья, отходами хлопка, натурального шёлка, вискозы, армированной пряжи, линейная плотность, экономического эффективности.

At the same time, it is possible to combine the high physical and mechanical properties of chemical threads and the natural properties of natural fibers. This effect is especially high provided that natural fibers completely encircle the core chemical thread. This is achieved by wrapping the core thread with a continuous screw layer. For the silk industry, which uses a limited assortment of threads, this direction allows one to obtain twisted threads of fundamentally new structures, taking into account that monofilament barbed threads. Although it is possible to have as a surge yarn a sufficiently liane staple silk fiber. The principle of obtaining a combined thread can be implemented both at the stage of unwinding cocoons and at the torsion stage, and can be used as continuous threads (raw silk), with enhanced consumer properties (nylon, cotton and others). Such a scheme is implemented both on silk-winding machines and in a spinning rotor machine PR-150-1.
In the first case, the surge thread is natural silk, in the second, discrete staple fibers (Fig. 1). The question naturally arises: what should be the twist of the reinforced yarn, if the diameter of the core thread is dc and the fibers are db, provided that the core thread is completely covered by fiber layers (Fig. 2).  It can be seen from the diagram that for one revolution of the core thread, the coil is raised by the length Lc, which is determined from two ratios: We divide the formula (1) by (2) and get the following It is obvious that the maximum number of fibers and threads is determined from the ratio () П dc db n db when the surge thread is parallel to the core (Fig. 2.1 For n> n1, a second layer of filament is formed.
With n = 1, you can calculate the thread with the maximum twist.
Obviously, for this it is necessary to create a twist.
For n1, we have R = 1 Formulas (4), (5), (6) and (7) are the basis for technological calculations in the production of reinforced yarn, with some correction for the non-circular cross-section of the fiber. Given the ratio between the diameters of the threads and the size of the twist (6). for any two components, it is possible to choose a ratio of feed rates and twist value that provides complete overlap of the surface of the rod and gives the complex filament the properties of natural fibers From the obtained formulas it is also obvious that the twist of the shaped yarn depends on the number of surplus threads. When n = 0, the twist will be minimal. When n = 1 -the maximum twist.
The choice of twist or the number of surge threads determines the performance of the machines, on the one hand, and the type and strength of the reinforced thread, on the other. CONCLUSIONS 1. The theoretical diameter of the reinforced yarn, as well as its dependence on the angle of inclination of the braiding fibers to the core thread, is calculated. 2. Theoretically, the effect of twisting on the strength of reinforced yarn is shown, depending on the composition of the core thread and fiber (through the angle of inclination of the fibers to the axis of the thread). 3. The maximum strength of the thread occurs when this angle is P / 4, the minimum (theoretically) -with the values of the angle zero and P / 2. In the first case, due to the lack of curvature at zero twist, in the second case, due to the arrangement of the fibers perpendicular to the core thread. 4. By calculation, the diameter of the reinforced thread is established as a function of the diameters of the core thread and fibers, as well as the conditions for braiding the core thread with fiber in one and two layers.
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