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Examining the effects of balloon control ring on ring spinning
Abstract
The ring spinning process has been used to produce fine and high quality staple fibre yarns. The stability of the rotating
yarn loop (i.e. balloon) between the yarn-guide and the traveller-ring is crucial to the success and economics of this process.
Balloon control rings are used to contain the yarn-loop, by reducing the yarn tension and decreasing the balloon flutter instability.
Flutter instability here refers to the uncontrolled changes in a ballooning yarn under dynamic forces, including the air drag.
Due to the significant variation in the length and radius of the balloon during the bobbin filling process, the optimal location
for the balloon control ring is not easily determined. In order to address this difficulty, this study investigates the variation
in the radius of a free balloon and examines the effect of balloon control rings of various diameters at different locations
on yarn tension and balloon flutter stability. The results indicate that the maximum radius of a free balloon and its corresponding
position depend not only on the yarn-length to balloon-height ratio, but also on yarn type and count. A control ring of suitable
radius and position can significantly reduce yarn tension and decrease flutter instability of free single-loop balloons. While
the balloon control rings are usually fixed to, and move in sinc with, the ring frame, results reported in this study suggest
that theoretically, a balloon control ring that always remains approximately half way between the yarn-guide and the ring
rail during spinning can lead to significant reduction in yarn tension.
... 5,6 There are few experimental investigations to characterize the dynamic yarn path, such as measurement of the yarn tension, balloon form, etc., during the ring spinning process. [7][8][9][10][11][12][13][14][15] The reason lies in the complexity of the dynamic behavior of the yarn path throughout the spinning process. Sonntag [7][8][9] investigated and analyzed quantitative measurements, including the yarn tension between the delivery rollers and the yarn guide, in addition to the yarn tension between the traveler and the cop for the conventional ring spinning process. ...
... 30 cN for the yarn count of 38 tex. In another publication, Tang et al. 11,12 investigated the tensile properties and elongation of the yarn in the balloon zone for different yarns with the help of a ballooning device. Their research revealed that the breaking force of the ballooning yarn is much lower than the yarn breaking force obtained from normal tensile tests. ...
... Only Sonntag [7][8][9] described a complete measurement system in order to characterize different process parameters, although he employed several measurement principles from previous works. The other studies [11][12][13] address a specially constructed apparatus, which rotates the spun yarn at a lower spindle speed. One of the most significant tests was carried out by Tang et al., 10 who tried to measure in situ balloon tension at a lower angular spindle speed using the constructed apparatus for the simulation of the yarn path. ...
The yarn tension and balloon form are the most important physical process parameters to characterize the dynamic yarn path in ring spinning. The present research work focuses on the in situ measurement of yarn tension in different regions of the yarn path in a developed turbo ring spinning tester with a friction-free superconducting magnetic bearing (SMB) twisting system and at an angular spindle speed of up to 50,000 rpm. The influence of different parameters, such as angular spindle speeds (15,000–50,000 rpm), yarn counts (15–40 tex) and balloon control ring (one or multiple), were evaluated to identify the influence of acting forces, for example, centrifugal forces. The effects of these process parameters were analyzed statistically using an analysis of variance. The yarn tension between the delivery rollers and the yarn guide was measured using a modified one-roller tensile yarn tension sensor. The yarn tension between the yarn guide and the SMB system was determined with an already existing optical approach at a higher angular spindle speed. As the highest yarn tension theoretically occurs between the SMB system and the cop, it was estimated in this region by measuring the coefficient of friction between the yarn and the yarn guide using the friction module of the constant tension tester equipment. The maximum balloon diameter was determined from the recorded balloon form between the yarn guide and the SMB system with respect to different angular spindle speeds. The results provide valuable information about the highest possible spinnable speed and enable a better understanding of the dynamic yarn path in the SMB spinning system.
... The results indicate that the maximum radius of a free balloon and its corresponding position depend not only on the yarn-length to balloon-height ratio, but also on yarn type and count. This study suggest that theoretically, a balloon control ring that always remains approximately half way between the yarn -guide and the ring rail during spinning can lead to significant reduction in yarn tension [21] . ...
For many years, during the spinning process the protruding fibers are formed in ring yarn structure. The protruding fibers are known as “Yarn hairiness”. This yarn hairiness reduces the quality of yarn and fabric and also it decreases the selling price of the yarn, because of the presence of yarn hairiness make uneven dyeing. Yarn hairiness is an important factor that affects the textile appearance, feel and usability, which is also very crucial to the quality assessment of the yarns. Now-a-days compact spinning is used to reduce the yarn hairiness. Hairiness in yarn is caused by raw material fault or by machine fault. The high percentage of short fibres in the cotton, lack of floating fibre control in the drafting zone are the main causes of producing hairiness in ring spun yarn. In this research work an attempt is made to reduce the hairiness level in the yarn by modified lappet design and providing suction pressure in the lappet zone. Also an attempt is made to alter the separator design to find the impact of reduction in hairiness of the yarn. The yarn is tested for its imperfection and hairiness index values using Uster tester. The results shows a positive node and we conclude that by the use of modified lappet and separator yarn can be produced with less imperfection and hairiness in the conventional type of ring frame.
Ring spinning is the dominant system of manufacturing high-quality yarns in the textile industry. Spinning parameters affect the spinning tension distribution and consequently the temperatures of the ring/traveler system. Excessive traveler heat will limit the spindle speed and the efficiency of yarn production. This study modeled the effect of the traveler weight, yarn count, twist level and spindle speed on the temperatures of the traveler and ring during ring spinning. The finite element method was used to model the temperatures of the ring and the traveler for different spinning parameters. The experimental ring temperature and maximum traveler temperature from the validated model were recorded based on the experimental design. The results show that spindle speed, traveler weight and yarn count had a statistically significant effect on the temperatures of the traveler and the ring, with the spindle speed having the strongest effect. The twist level of yarn, within the range examined, had no statistically significant influence on the traveler and ring temperatures. For a given spindle speed, the traveler weight and yarn count have a significant effect on the maximum temperature of the traveler, and the temperature change is more pronounced at a higher spindle speed.
The productivity of the conventional ring spinning process is currently limited by the frictional heat that occurs in the ring/traveler twisting system. In the framework of a fundamental research project from the German Research Foundation (DFG), the levitation principle of superconducting magnetic bearing (SMB) was implemented as a twisting element in order to eliminate the frictional problem and thus aim, at least, to double the productivity. A mathematical model of the dynamic yarn path has already been presented considering the friction free SMB system up to an angular spindle speed of 25.000 r.p.m. In this paper, the existing theoretical model, which was developed up to 25.000 r.p.m, was further modified considering the balloon control ring and yarn elasticity at a higher angular spindle speed, such as 50.000 r.p.m. The model was solved numerically using the Runge-Kutta method. With this model, it is possible to estimate the yarn tension distribution and balloon form considering the above-mentioned parameters. The model established was further validated by comparing the yarn tension and balloon forms predicted with measured ones up to an angular spindle speed of 15.000 r.p.m in a ring spinning tester based on superconducting magnetic bearing. © 2018, Institute of Biopolymers and Chemical Fibres. All rights reserved.
Control of process parameters is extremely important in ring and rotor spinning to ensure production of yarns with the desired quality at the highest possible speed and with minimum waste. The chapter discusses the importance of different key process parameters and their influence on process performance and quality of yarns. It also discusses the effect of different factors on those key process parameters.
Compared to other spinning system, the ring spinning process has been used to produce higher quality yarns, but with a much lower spinning efficiency, resulted from the relatively high spinning tension that leads to increased yarn breakage rates and makes high power consumption. Thus, depressing yarn tension is essential to change the status. In this paper, we design a movable balloon controller system to reduce yarn tension. The system is automatic, composed of powder switch, touch screen, PLC (Programmable Logic Controller), pulling-thread displacement sensor, controller of step motor, step motor and linear module. PLC, the core of the system, controls the position of the balloon controller by a series of programs. Then yarn tension was tested while spinning with movable balloon control ring, fixed balloon control ring and no balloon control ring, respectively. The result shows that the yarn tension can be depressed indeed by equipping this movable balloon controller system to some extent. Additionally, we find that the number of hairiness of ring spun yarns with this system can be reduced to some extent, while yarn tensile properties are not as sensitive to be worse. It is significant to cut down ends-down rate, improve the quality of ring spun yarns, the spinning efficiency as well as the energy efficiency of ring spinning.
The geometrical model of yarn currently in use is assumed to be a circular cylindrical under the bending deformation, but
this assumption is not really true because the cross-section of yarn has to change to an elliptic shape when the compressive
force acted on the yarn is considered. Therefore, as the first part of a series of work, the present paper considers the fact
that yarn geometry changes from a circular cylindrical to an elliptical cylindrical under an external applied bending moment,
and then analyzes the relationship of bending rigidity between constituent filaments and the formed yarn, which is useful
in predicting or selecting specified bending property of filaments by the requirements of yarn. In the present paper, the
bending and torsional energies stored in filaments are analyzed according to their deformations by the energy method. The
explicit formula is then obtained to quantify the bending rigidity relationship between the filament and yarn, in which four
characters are featured as the eccentricity of elliptical cross-section of yarn, the ratio of bending to torsional rigidity
of filament, the helix angle of the filament on yarn surface and the number of filaments inside the yarn. Moreover, the bending
rigidity of filament yarns formulated by an earlier method with a circle shape assumption can also be obtained by the proposed
method with the eccentricity being equal to zero. Based on the analytical solution, the earlier method in which the circle
shape takes place of the elliptical shape of yarn for simplification can also be evaluated. This will be depicted in the Part
II of this series of work, in which the relative error between the ideal and revised model would be analyzed, and the numerical
simulations of relationship between filament and yarn would also be made.
In a number of recent papers, the theory of a rotating yarn loop (called a yarn balloon) has been applied to model the operation of the industrially important process of ring spinning, and the exploration of the seven-dimensional solution space of these nonlinear equations has been well begun. In modern ring-spinning machines, the size of the yarn balloon is limited by placing one or more control rings around each spindle. In this paper the theory of these balloon-control rings is further developed, and computational results for a representative ring-spindle geometry, yarn-air-drag and frictional parameters are given. These results show that, in addition to lowering yarn tension, the main effect of the control ring is to greatly extend the region of parameter space over which dynamically stable balloons are formed. Finally, it is shown how the stability boundaries of this multidimensional parameter space can be projected and mapped to make this information useful for the ring-spinning industry.
A description of an apparatus for measuring balloon characteristics is given here together with the use to which it has been put in measuring the air-drag of textile yarns and certain coefficients of friction.
The paper gives an outline of a spinning system, now the subject of British Patents, which can be effectively used to increase the production of ring frames, particularly of the long-lift type.
Equations developed in a previous paper¹ are extended to cover the case of balloons described by compounded Cartesian equations*, and the possibilities of obtaining reduced yarn tension, constant yarn tension, and higher spindle speed are explored. As in the previous work, air drag has been neglected. This factor, which can be calculated, has in the present instance and on the machine considered been found negligible up to the speeds so far envisaged, but the relative effect is discussed in the text.
Details are given of tests carried out under normal spinning conditions to cross-check the validity of the theory and its application to long-lift, large-package machines. The relation between centrifugal force and yarn tension is discussed and the inter-relation of spinning tension and winding tension with balloon variation is demonstrated.
The effects of traveller friction and yarn friction are explored and values arrived at for these factors. Curves are given showing the variation of spinning and winding tension with balloon length.
It is concluded that the application of controlled balloon spinning to long-lift, large-package machines will allow substantial increase of spindle speeds under the derived conditions, and that constant tension through the package build can be maintained.
Some details are also given of preliminary larger-scale trials of the system and this will be more fully discussed in another paper at a later date.
This paper describes the procedure adopted and some of the results obtained in experiments designed to investigate the possibility of using radioactive tracer fibres to study the mechanism of carding. A small-scale card, with stationary flats, was used and, in the experiments described, either one or two flats were employed. Summarized results of observations of the passage through this card of more than 600 fibres are given and their interpretation is discussed.
An assessment is made of the value of the radioactive tracer technique for the investigation of carding behaviour.
Air-drag on a ballooning yarn and balloon shape affect the yarn tension and ends-down (yarn breakage), which in turn affects energy consumption and yarn productivity in ring spinning. In this article, a mathematical model of yarn ballooning motion in ring spinning is established. The model can be used to generate balloon shape and predict tension in the ballooning yarn under given spinning conditions. Yarn tension was measured using a computer data acquisition system and the balloon shapes were captured using a digital camera with video capability during the experiments using cotton and wool yarns at various balloon-heights and with varying yarn-length in the balloon. The air-drag coefficients on ballooning cotton and wool yarns in ring spinning were estimated by making a “best fit” between the theoretical and experimental turning points. The theoretical results were verified with experimental data. The effects of air-drag and balloon shape on yarn tension are discussed.
The mathematical model for balloon formation in the ring spinning
process has been well established since the mid-1950s. The availability
of present day computational power has made it possible to carry out a
comprehensive analysis of the equations which it is hoped will give
fresh insight into the physics of ring spinning. This paper is mainly
concerned with free balloon spinning (without control rings). The
relation between guide eye tension and traveller mass is explored in
detail and an important transition region in this dependence is
identified. The dependence of this transition region on bobbin radius,
balloon height and air drag is also examined in detail. The practical
application of the theory is discussed and theoretical minimum traveller
mass against balloon height curves are produced. The results of a
simulation of one traverse of the ring rail up and down the conical
chase of a cop-structured bobbin is presented. Finally, the theory is
modified to allow for the presence of a control ring and results that
show the effect of the control ring on the guide eye tension against
traveller mass dependence are presented.
An account is given of the physical phenomena involved in ring spinning, and of the factors determining yarn tensions and balloon shapes. The treatment described is applicable to free balloons or to balloons formed between control rings, and enables a semi-quantitative description to be given of the way in which yarn tensions and balloon shapes change as the diameter of the package and the height of the balloon change. It is shown that the balloons formed in ring spinning can be regarded as part of a stationary wave system of circularly polarized transverse vibrations on a string. The wavelength can be calculated as a function of the maximum radius of the balloon, and it is shown that the maximum length of free balloon that can be formed without a neck is πP, where P = . (m is the mass per unit length of the yarn and ω is the angular velocity of the traveller.) For any ring radius and balloon height, the shape of the balloon can be determined when the tension T 0 in the yarn between thread guide and rollers is known. It is shown how this tension depends upon (a) ring-traveller friction, (b) yarn-traveller friction, (c) air-drag on the yarn in the balloon, and (d) balloon shape. For a given mean winding tensiori (the tension in the yarn as it is wound on to the bobbin), the greater the air-drag forces on the balloon, i.e. the greater the spindle speed or the height and diameter of the balloon, the srnaller T 0 can be. It is also shown that the use of balloon control rings, in addition to enabling the maximum height of the balloon to be increased, also reduces the fluctuations in T 0, caused by irregularities in the movement of the traveller round the ring.
This article reports theoretical and experimental investigation on yarn snarling and balloon fluttering in ring spinning. Yarn snarling and balloon fluttering affect yarn breakage in ring spinning. The theoretical model has incorporated the tangential component of air drag on a ballooning yarn, which was ignored in previous models. The results show that yarn snarling happens in the balloon when the ratio of yarn length in the balloon to balloon height is greater than a specific value that depends on the yarn type and count. Yarn tension experiences an obvious change before and after yarn snarling. The balloon flutter appears between normal balloons while the balloon loops are changing. Fluttering balloon shapes that oscillate periodically between two and three loop configurations as yarn tension varies periodically have also been observed experimentally.
Yarn tension is a key factor that affects the efficiency of a ring spinning system. In this paper, a specially constructed
rig, which can rotate a yarn at a high speed without inserting any real twist into the yarn, was used to simulate a ring spinning
process. Yarn tension was measured at the guide-eye during the simulated spinning of different yarns at various balloon heights
and with varying yarn length in the balloon. The effect of balloon shape, yarn hairiness and thickness, and yarn rotating
speed, on the measured yarn tension, was examined. The results indicate that the collapse of balloon shape from single loop
to double loop, or from double loop to triple etc, lead to sudden reduction in yarn tension. Under otherwise identical conditions,
a longer length of yarn in the balloon gives a lower yarn tension at the guide-eye. In addition, thicker yarns and/or more
hairy yarns generate a higher tension in the yarn, due to the increased air drag acting on the thicker or more hairy yarns.
A Practical Guide to Ring Spinning
- W Klein
- W. Klein