CC BY
11
Djumabaev Gulomjon Xalillaevich, senior teacher,
Zhumaniyazov Kadam Zhumaniyazovich,
professor,
Matismailov Saipilla Lolashbaevich, assistant professor, Tashkent Institute of Textile and Light Industry E-mail: 0dil_2005@rambler.ru
RESEARCH OF INFLUENCE OF THREAD GUIDERS WITH FLEXIBLE ELEMENTS FOR THE PROCESS OF YARN FORMATION
Abstract: The article presents a study of the effect of the yarn guider with elastic elements on the yarn formation process. At the fitting of thread guider of a new design with elastic elements, the conditions for twist propagation to the yarn formation zone are improved. At the result of the increasing in the uniform tension of the yarn and a better straightening of fibers, the breaking load of the yarn and its elongation is increased, the unevenness of the cross-section and the breaking load as well as the breakage on spinners up to 20 were reduced.
Keywords: Spinning machine, thread guider, exhausted device, twist, stability, elasticity, linear density, coefficient of variation, conductivity breaking load, breakage, yarn.
The technological process on ring spinners is designed so that at the same time there is a twisting of the thread and winding it on the pirn. This operation is carried out by a twinned-winding mechanism consisting of delivered pair of exhausted device, a thread guider, a spindle, a ring and a roller. The greatest tension of the thread during ring spinning occurs in the area between the roller and the pirn, because of the thread tension in balloon but also the centrifugal force of the roller, as well as the friction force of the roller on the ring and the thread on the roller. However, thread breakage mostly often occurs between the thread guider and the front cylinder of the exhausted device, where the low-twisted thread has the lowest strength [1].
Based on the above mentioned, an experimental study of the effect of a flexible threads guider on breakage and yarn quality indicators were conducted.
Experimental studies were carried out under production conditions ofJV LLC "Uztex Shovot".
Evaluation of the influence of the thread guider construction on the yarn formation process and its quality was carried out during generating a 20-tex linear density yarn on a G-35 ring spinning machine Rieter.
Two designs of thread guiders mounted on the same spindles were investigated:
- consisting of a hook of steel wire, which forms a loop for the passage of the thread (factory);
- thread guiders manufactory with elastic elements (experienced).
The effectiveness of thread guides of different designs was evaluated by the following indicators:
- twist in the zone of formation of yarn, tw/10sm;
- conductivity breaking load of yarn, sN/tex;
- coefficient of variation for breaking load,%;
- breakage of yarn per 1000 tw.
The yarn quality was assessed by testing on laboratory equipment from Uster as well as the twist of yarn and its stability on the Auto Twist Context twister.
Breakage was recorded during the time of removal. All tests were carried out in 3 replications and measurements of twist in the yarn formation zone in five replications.
Thread guiders are the main device that prevents the spread of twist in the zone of formation of the DB yarn (Fig.1) because of the bending of the thread in the thread guider (angle f).
As a result, a sliver at zone hB does not receive sufficient strength and even a slight oscillation of the thread can lead to its breaking [2].
Theoretical studies show that the new design of thread guiders allows to increase the spread of twist in the zone DB by reducing the rigidity of the structure and increasing its flexibility in the zone of the bend of the thread.
To confirm this position, measurements of twist in the DB zone with sequential installation of the compared structures of the thread guiders were made.
To do this, with the help of special clamps, a portion of the DB thread (when the body of the cob was developed) was transferred to a twist meter to determine the twist.
The results ofthe measurements are shown in the (table 1).
From table 1 it can be seen that while using steel thread guiders, the average twist per 10 sm. of yarn in the zone of its formation was 58.4 twists, i.e. these thread guiders delay to 29.64% twist (refueling twist is 830 tw/m).
RESEARCH OF INFLUENCE OF THREAD GUIDERS WITH FLEXIBLE ELEMENTS FOR THE PROCESS OF YARN FORMATION
Figure 1. Scheme of the formation of yarn Table 1.- Twist in zone of yarn formation
Thread guider Twist for 10 sm Coefficient of variation for twist,%
1 2 3 4 5 middle
Steel 58 62 60 57 55 58.4 4.14
With elastic elements 72 70 73 69 72 71.2 2.67
At the installing of thread guiders with elastic elements, the average twist per 10 cm of yarn in the DB zone was 71.2 twists, i.e. the conditions for the spread of twist are reduced and these thread guiders delay only 14.22% of twist. Thus, we see that the increase in the twist in the thread guiders -the exhausted roller at the installing of the thread guiders of new design is 15.42%. The spread of twist in this area has become more uniform: the coefficient of variation in the twist is 2.67%, which significantly stabilizes the vibrations of the thread. At the working on steel thread guiders, the coefficient of variation of twist on the DB section is 1.47 times greater and amounts to 4.14%.
Table 2.- Indicators of physical
To assess the degree of influence of the design of the thread guiders on the quality and the process of forming the yarn successively (changing the thread guiders) on the G 35 ring spinning machine, a yarn with linear density of 20 tex was produced.
The main indicators of the physic-mechanical properties of the yarns of both variants were determined by testing of the yarns on the USTER TENSORAPID4 instrument. Average test results are shown in (Table 2 and in Fig. 2).
The yarn of both options meets the requirements of regulatory technical documentation.
and mechanical properties of yarn
№ The name of indicators Steel Thread Guider Elastic Thread Guider
1 2 3 Mid. 1 2 3 Mid.
1. Linear density tex 20.1 20.2 20.0 20.1 20.2 19.9 20.1 20.0
2. Coefficient of liner density variation,% 0.9 0.92 1.0 0.94 0,89 1,01 0,93 0.94
3. Breaking load, sN 242.8 240.0 240.2 241.0 252.2 251.2 249.8 251.0
4. Coefficient of variation for breaking load,% 10.1 9.7 9.6 9.8 8.9 8.6 8.3 8.6
5. Specific breaking load, sN/tex 12.28 11.88 12.01 11.99 12.5 12.62 12.43 12.52
6. Lengthening,% 3.98 3.92 3.9 3.93 4.24 4.18 4.27 4.23
7. Breakage at 1000 tw/h for 100 km of yarn 56 62 58 58.7 48 43 45 45.3
In the study of flexible thread guiders, the specific tensile load of the yarn was 12.52 sN/tex, which is 0.53 sN/tex higher than at working with a steel thread guider (11.99 sN/tex), i.e. conditions for the formation of yarn are improved, the fibers are
straightened better and at the breaking the slippage of the fibers is decreased. The quadratic unevenness of the cross-section and the breaking load decreases from 9.8% to 8.6%, the elongation of the yarn increases by 0.3%, i.e. we get more sound yarn.
Figure 2. The main indicators of physical and mechanical properties of yarn
In the study of flexible thread guiders, the specific tensile load of the yarn was 12.52 sN/tex, which is 0.53 sN/tex higher than at working with a steel thread guider (11.99 sN/ tex), i.e. conditions for the formation of yarn are improved, the fibers are straightened better and at the breaking the slippage of the fibers is decreased. The quadratic unevenness of the cross-section and the breaking load decreases from 9.8% to 8.6%, the elongation of the yarn increases by 0.3%, i.e. we get more sound yarn.
Observation of a break during the removal period showed its decrease from an average of 58.7 breakings per 1000 spindles per hour to 45.3 breakings per 1000 tw. hour, i.e. by 22.8%.
Conclusions:
1. At the installing of thread guiders of a new design with elastic elements, the conditions for spreading twist to the yarn formation zone are improved: the twist increase was 15.42%, while the uniformity of twist spread was increased for 1.47 times, which significantly stabilizes the amount of thread oscillation.
2. At the result of thread uniform tension increasing and a better straightening of the fibers, the breaking load of the yarn was increased; the elongation and unevenness in the cross-section and the breaking load were decreased as well.
3. New design of thread guiders helps to reduce thread breakage on spinning machines to 20.
References:
1. Makarov A. I. and others. Calculation and design of spinning production machines.- M; Mechanical Engineering, 1981.379 p.
2. Pavlov Yu. V. and others. The theory of processes, technology and equipment for cotton and chemical fibers spinning. Ivanova: Regional Printing House, 2000.- P. 148-151.
