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Pneumatic compact spinning is the most widely used compact spinning method at present, in which the negative pressure airflow is used to condense the fiber bundle and decrease the spinning triangle. Compact spinning with perforated drum and lattice apron are mainly two kinds of pneumatic compact spinning now. The purpose of this paper is to study the comparative analysis on four kinds of pneumatic compact spinning systems, including two kinds of compact spinning with perforated drum: Rieter’s COM4 and complete condensing spinning (CCS), two kinds of compact spinning with lattice apron: Sussen’s three-line compact spinning (TLCS) and Toyota’s four-line compact spinning (FLCS).

First, the basic properties of four systems were introduced and comparatively analyzed. Then, the 29.2 tex (20S), 14.6 tex (40S), 9.7 tex (60S) and 7.3 tex (80S) combed cotton yarns were spun in the four pneumatic compact spinning systems and ring spinning system, respectively. The evenness, breaking strength and hairiness of spun yarns were tested. Finally, the properties of corresponding woven fabric were tested.

It is shown that comparing to compact spinning with lattice apron, the disposable input cost of compact spinning with perforated drum is higher, but the maintenance cost is lower. Comparing to compact spinning with lattice apron, the evenness of yarn spun by compact spinning with perforated drum is improved whereas the breaking strength is decreased. Furthermore, although harmful long hairiness (=3 mm) of yarn spun by CCS is a little more, the beneficial short hairiness (1-2 mm) is also more, which can make the fabric fullness and have better comfortable feeling.

In the paper, comparative analysis on four kinds of pneumatic compact spinning systems, compact spinning with perforated drum: Rieter’s COM4 and CCS, and compact spinning with lattice apron: Sussen’s TLCS and Toyota’s FLCS, were studied. The basic properties, spun yarn qualities and properties of corresponding woven fabric of four systems were analyzed comparatively.

This paper aims to present the impact analysis of payload rendezvous with tethered satellite system and the design of an adaptive sliding mode controller which can deal with mass parameter uncertainty of targeted payload, so that the proposed cislunar transportation scheme with spinning tether system could be extended to a wider and more practical range.

In this work, dynamical model is first derived based on Langrangian equations to describe the motion of a spinning tether system in an arbitrary Keplerian orbit, which takes the mass of spacecraft, tether and payload into account. Orbital design and optimal open-loop control for the payload tossed by the spinning tether system are then presented. The real payload rendezvous impact around docking point is also analyzed. Based on reference acceleration trajectory given by optimal theories, a sliding mode controller with saturation functions is designed in the close-loop control of payload tossing stage under initial disturbance caused by actual rendezvous error. To alleviate the influence of inaccurate/unknown payload mass parameters, the adaptive law is designed and integrated into sliding mode controller. Finally, the performance of the proposed controller is evaluated using simulations. Simulation results validate that proposed controller is found effective in driving the spinning tether system to carry payload into desired cislunar transfer orbit and in dealing with payload mass parameter uncertainty in a relatively large range.

The results show that unideal rendezvous manoeuvres have significant impact on in-plane motion of spinning tether system, and the proposed adaptive sliding mode controller with saturation functions not only guarantees the stability but also provides good performance and robustness against the parameter and unstructured uncertainties.

This work addresses the analysis of actual impact on spinning tether system motion when payload is docking with system within tolerated docking window, rather than at the particular ideal docking point, and the robust tracking control of deep-space payload tossing missions with the spinning tether system using the adaptive sliding mode controller dealing with parameter uncertainties. This combination has not been proposed before for tracking control of multivariable spinning tether systems.

Solospun technology is one of the most important new spinning methods, which is implemented by dividing Ring spinning triangle into several small primary triangles and one final triangle by a Solospun roller. That is, there are two parts of spinning triangle in the Solospun technology, including primary triangles part and final triangle part. In the general case, the primary triangles are much smaller than final triangle. Therefore, the purpose of this paper is to present theoretical study of Solospun yarn torqueby linking the fiber tension in the spinning triangle to yarn torque under the assumption that the primary triangles and the primary twist are ignored.

The theoretical model of the residual torque within Solospun yarn due to the fiber tension was given. Then, as an application of the proposed method, 14.6 tex cotton yarns were taken as an example for the numerical simulations. The fiber tension in the Solospun spinning triangles and corresponding yarn torque were simulated numerically by using Matlab software. The relationships between yarn torque and spinning triangle parameters are analyzed according to the simulation results. Furthermore, the properties of spun yarns produced by the Solospun and Ring spinning system are evaluated and analyzed by using the simulation results.

It is shown that comparing with the Ring spun yarn, Solospun yarn torque is a little larger. Meanwhile, with an increase of substrand number, the fluctuation of curve of average fiber tension in Solospun system is increased firstly, and then decreased, i.e. showing parabola shape, potentially leading to corresponding change of yarn torque.

In this paper, theoretical study of Solospun yarn torque is presented by linking the fiber tension in the spinning triangle to yarn torque under the assumption that the primary triangles and the primary twist are ignored. The theoretical model of the residual torque within Solospun yarn due to the fiber tension was given.

Pneumatic compact spinning is the most widely used compact spinning method at present, in which the negative pressure airflow is used to condense the fiber in order to decrease the spinning triangle and improve the yarn qualities. Therefore, the research on flow field in the condensing zone is always the emphasis for pneumatic compact spinning. The paper aims to discuss these issues.

By using finite element method (FEM), the flow field in two kinds of pneumatic compact spinning was studied. Taking three kinds of cotton yarns as examples, with the help of high-speed camera system OLYMPUS i-SPEED3, the motion trajectory of fiber strand in the condensing zone was obtained. Three-dimensional physical models of the condensing zone of the two compact spinning systems were obtained according to the measured parameters of practical spinning systems.

It is shown that on the both left edge of B1 line and right edge of B2 line, the airflow inflows to the center line of suction slot, and the condensed effects are produced, correspondingly. In the condensing zone, there are three condensing processes acting on the fiber strand, including the rapid condensing effects in the front condensing zone, the adequately condensing effects in the middle condensing zone, and stable output effects in the back condensing zone.

By using FEM, numerical simulations of three-dimensional flow field in condensing zone for two kinds of pneumatic compact spinning with lattice apron were presented, and corresponding spun yarn qualities were analyzed.

Ring spinning is the most widely used spinning method at present. In the spinning, ring and traveller are the two important components of the twisting process. The properties of ring and traveller have a direct relationship with the yarn qualities and spinning speed. Therefore, the purpose of this paper is to study the mutual relationships of flange ring and traveller system by taking the 6802-type traveller with rectangular structure, BU-type traveller with toxoplasma structure and 772-type traveller with corrugated structure as examples.

First, the theoretical calculation models of force and inclinations of the traveller are given, and calculation methods of corresponding key parameters referred in the models are presented. Then, by using SolidWorks software, models of the three kinds of traveller straddling on the PG1-4254 type ring are built, and the traveller and ring are simulated by using ADAMS software. By using MATLAB software, the force and inclinations of the traveller during the rotation around ring are simulated. Finally, the spinning experiments are made.

It is shown that the abrasion of 6802-type traveller is the most serious, and corresponding yarn evenness and hairiness is the worst. The abrasion of BU-type traveller is the slightest, and corresponding yarn evenness is the best. The yarn spins by using 772-type traveller has the least hairiness.

In the paper, the mutual relationships of flange ring and traveller system have been studied. For giving analysis of force and inclinations of the traveller, calculation methods of the key common parameters are presented. By using SolidWorks software, the physical models of the three kinds of traveller straddling on the PG1-4254 type ring are built. And then, the force and inclinations of the traveller during the rotation around ring are simulated by using MATLAB software. At last, the spinning experiments are made to analyse the simulation results.

The purpose of this paper is to know airflow field and its distribution of pneumatic compact spinning systems. Complete compact spinning (CCS) and four-line rollers compact spinning (FRCS) are both two kinds of pneumatic compact spinning systems, which utilizes airflow in condensing equipment to condense fiber bundle and improve yarn properties.

The paper opted for an exploratory study using finite element method, the airflow field in the condensing area of CCS and FRCS were simulated. First, a periodic movement of the fibers in bundle in condensing area was detected, and the yarn tracks were described veritably under the high-speed-video-camera and AutoCAD Software. Then the physical models of the condensing zone were constructed according to the physical parameters of the practical system. The simulation of airflow velocities were extracted along the yarn tracks using ANSYS Software. Finally, the numerical results were verified by spinning experiments.

The results show that the negative velocity component along the Y-axis helps keeping beneficial hairiness. CCS has higher negative velocity value and more abundant beneficial hairiness than FRCS. The velocity component in the X-axis direction has a direct effect on yarn evenness. For the same liner density of CCS and FRCS, the larger the value of the velocity component on X-axis is, the better the yarn evenness is. For 9.7tex, CCS has larger velocity component in the X-axis direction and better yarn evenness than FRCS, showing that CCS is more suitable for spinning fine count yarn. The velocity component in the Z-axis direction has a direct effect on breaking strength. CCS has little velocity component in the Z-axis direction and little breaking strength than FRCS.

To know airflow field and its distribution by finite element method is helpful to investigate the condensing principles of the fiber bundle and improve yarn properties.

Most researchers have neglected the effect air-drag force on yarn tension during rotor spinning. This paper aims to study the effect of rotor air-vacuum pressure in conjunction with opening roller speed and yarn linear density on the yarn tension generated during the rotor spinning, which has established their significant influences on both the mean and the peak tension.This is the first of one-of-a-kind experimental study being reported to demonstrate the influence of air-drag force on yarn tension during the rotor spinning under dynamic condition.

The dynamic measurements on yarn tension at the exit of the doffing tube were carried out by using an electronic capacitive yarn tension meter during rotor spinning. The derived experimental data were fitted into equations to construct the response equations and to work out the coefficients of multiple correlation between the data and the predicted equation for both the mean and the peak tension. Various surface plots were constructed by using those response surface equations, so as to study the effect of variables on yarn tension generated during the rotor spinning.

The study has established that the rotor vacuum is responsible in causing a change in yarn tension, it increases with the decrease in air-vacuum inside the rotor. The involvement of the opening roller speed in altering yarn tension during rotor spinning has been proved. As the opening roller speed changes, so does the air stream surrounding the opening roller speed with consequent alteration of the centrifugal force generated due to the rotation of the rotor. The centrifugal force and, hence, the yarn tension generated in the rotor will be simultaneously affected by both the rotor relative vacuum and the opening roller speed.

This is a structured experimental study to verify the influence of air-drag force generated during rotor spinning on yarn tension. Very limited theoretical work has been carried out in this direction as reported in the introductory part of the paper. The result of the present study will encourage future researchers to revisit the theory on generation of air-drag force during rotor spinning and work out a new formula.

Next only to the conventional ring spinning system, the rotor spinning holds the second place in the share of global yarn production. Because of its advantage of lower cost of production and amenability to automation, the rotor spinning has gained acceptance in spun yarn production, particularly for spinning coarse and medium counts of yarns. Currently, it has acquired about 25 per cent share in the world’s spun yarn production. As many of the rotor machine variables significantly affect fibre configurations and, subsequently, the yarn properties by influencing the airflow characteristics inside the rotor unit, the study of yarn tension during rotor spinning and its analysis assumes a significance.

Rotor spinning is a relatively new and faster method of conversion of discrete fibres into continuous staple yarn and, subsequently, various textiles and garments. Its yarn is distinct and a bit different compared to the conventional ring yarn. It has got wide acceptance in the market and fashion. As such, the spinning sector that converts fibres into yarns is an important industry world over, providing employment to many. Besides, being the basic operation in the fibre value chain, it supports many downstream activities, including human clothing and fashion. Thus, the research on rotor spinning, particularly the yarn engineering to produce better products will be helpful to strengthen and grow the textile value chain.

This is an original research study. The magnitude and the direction of the air drag on the yarn during rotor spinning is very difficult to assess. Thus, most researchers for the sake of simplicity in analysis have neglected its effect on yarn dynamics, but a few of them have taken note of it in their theoretical propositions. However, no experimental result has been reported so far in the literature, supporting the influence of such air-drag force on yarn tension in the rotor spinning. In fact, none of the above studies have considered the induced effect of centrifugal force caused because of the rotation of the opening roller on the airstream that flows from the transfer channel inlet into the rotor because of its partial vacuum, causing consequential effects on air-drag force and tension in the yarn inside the rotating rotor. This is the first of one-of-a-kind experimental study being reported to demonstrate the influence of air-drag force on yarn tension during the rotor spinning under dynamic condition.

The purpose of this paper is to define the relationships between the first spinning zone of the hollow-spindle spinning system and technological parameters of manufacturing multi-thread fancy yarn.

A simple mathematical equation was introduced to account for the effect-thread helices. The validity of this equation was tested using visual observations of the helices of the effect thread in terms of their number, width and regularity and then compared against the theoretical values.

It was found that higher overfeed ratios increased the diameter of the helices without affecting their number, while increasing the rotational speed increased their number but reduced their diameter. The effect of these changes on the fancy yarns was that higher number of helices resulted in more fancy profiles while wider helices resulted in larger fancy profiles.

This research offers fancy yarn manufacturers a better understanding of the manufacturing process of fancy yarn and its practical advantage is to help them in determining the type of the resultant fancy yarns by controlling the geometry of the first spinning zone.

Air permeability of knitted fabrics is normally measured for the samples in their unstretched state. But, this air permeability values indicate the ability of these garments to allow air through them when they are not in use. But, the real-time condition is different and certainly the knitted garments mentioned above will subject to a degree of stretch during their usage. So, the measurement of air permeability under stretch and the fabric properties which would influence the air permeability of weft-knitted fabrics in their stretched state is of paramount importance. The paper aims to discuss these issues.

The aim of this research work is to investigate the change in air permeability values under the incremental extension of cotton tubular weft-knitted fabrics produced from the yarns of different spinning systems.

From the results, it is evident that the pique fabric samples of compact spun yarn displayed the highest air permeability values during the incremental stretch at all the three relaxation states. It is followed by the pique samples of ring spun yarn. Next to pique samples, the jersey samples made from the compact yarn and ring spun yarn revealed more air permeability, respectively. The core spun pique samples and core spun jersey samples displayed the least air permeability values, respectively. But, the pique and jersey samples made up of ring yarn and compact yarn showed gradual reduction in their air permeability towards the incremental stretch and the core spun pique samples and core spun jersey samples were uniformly seen with gradual increase in their air permeability during the incremental stretch.

Very limited quantity of research has been carried out in this area. So, a novel attempt has been made in this research work to investigate the influence of incremental stretch on air permeability of single knit structures.

The paper aims to provide an investigation about the effect of some selected production parameters such as core yarn type, sheath sliver type and total yarn count factors on core spun vortex yarns' evenness, imperfection and tensile properties. Hence it is aimed to contribute to the literature in vortex spinning where there are limited works related to core-spun vortex spinning.

The paper evaluates the effect of core yarn type, sheath sliver type and total yarn count factors on yarn evenness, imperfections, hairiness and tensile properties. Completely randomised three-factor analysis of variance (ANOVA) was conducted in order to evaluate the effect of core yarn type, sheath sliver type and linear yarn density on core spun vortex yarns' evenness, imperfection and tensile properties at significance level of 0.05. SNK tests were also performed for observing the means of each parameter. Correlation analysis was also conducted to reveal some relationships between yarn evenness and yarn tensile properties.

In this paper, significant factors related to some production parameters affecting the core-spun vortex yarns' evenness, imperfection, hairiness and tensile properties were found.

There are limited works related to effect of selected production parameters on yarn evenness, Imperfections and Tensile Properties of Hybrid Vortex Yarns.