An Overview on the Spinning Triangle Based Modifications of Ring Frame to Reduce the Staple Yarn Hairiness

Traditional ring spinning system is associated with the several limitations, one of which is yarn hairiness. The awareness has been vibrantly growing among the spinning mills for reducing staple yarn hairiness because of its detrimental effects on the subsequent processes (i.e., weaving, knitting, dyeing etc.) and the quality of resultant textile products. As a result, modified form of ring frame has attracted a lot of attention among the researchers for making yarn with the lower level of hairiness value. Besides the raw material parameters and some processing variables, spinning triangle (ST) is the most critical region that has decisive influence on the distribution of fiber tensions and their spatial orientations and shapes in staple yarn body. Thus, using appropriate methods to control the spinning triangle geometry actively has been a vital issue in the field of yarn hairiness reduction. In this paper, it is attempted to make an overview on the spinning triangle based modifications of ring frame that have been designed and destined to reduce hairiness. However, agent aided ring spinning system has also been briefly discussed in this paper as well.

Motion of Positive Winding of Ring Spinning Frame

The problems of the bobbin capacity and the high speed unwinding yarn taking off the ring or not during the winding of the ring spinning machine were dealt with. The mathematical model of the ring winding machine motion law was analyzed and optimized.Through the analysis and study of the movement rule of bottom bobbins and the ring spinning frame spool forming, the mathematical model of active bottom bobbins forming movement was established. Also,the mathematical model of bobbins formation was simulated and optimized. The concept of "controlled nail"was put forward. On this basis,the mathematical model of the current tube forming motion was optimized. The experimental results demonstrated that the theory of"controlled nail"met the high-speed spinning winding theory. The theory of "controlled nail "not only did the capacity of the bobbin increase,but also the spinning speed and efficiency are both improved,reducing the high-speed winder winding off. This research could provide a theoretical basis for the development of a new ring spinning frame.

Effects of lanthanum on properties of cathode materials and ion implanted spinning rings

The effects of rare earth elements on the structure of cathode materials composed of WC, 663Cu and Ti as well as the performances of spinning rings implanted with this cathode materials were investigated. The results show that rare earth elements can improve the microstructure and compactness of the cathode materials, and elevate the wear resistance and corrosion resistance of spinning rings implanted with these materials. Consequently, the yarn quality is improved significantly.

A METHOD FOR REDUCING YARN HAIRINESS AT RING SPINNING

In order to improve the quality of yarn,a research was carried out at ring spinning.A modifiedtraveller has been used to reduce the yarn hairiness vastly.According to the statistical analysis ofthe data,it was found that the geometrical shape of travellers is the key factor affecting the yarnhairiness at ring spinning.

STUDY ON THE RING SPINNING SYSTEM WITH A FIXED BELL SHAPED BALLOON CONTROLLER

On the basis of analyzing the typical kinds of balloon controllers used now, this article provides a new type one named Fixed Bell Shaped Balloon Controller. Experiments have been made to verify the function of it. Results indicated that the facility has quite good effect on the improvement of yarn quality and properties in addition to controlling yarn tension.

DYNAMIC STABILITY OF SPINDLE BLADE IN RING SPINNING Zhou Bingrong(Department of Mechanical Engineering)

It is discussed that a tangential force T induces a self-excited vibration in the motion ofspindle blades of a ring spinning frame.Depending on the relative magnitude of the tangentialforce compared with the tangential damping force the motion of blade is either stable orunstable.The chief factors causing the self-excited vibration can also be traced from the charac-ter of the experimental locus.

Study on Properties of Jute Fibres Spun on Ring Spinning System

Jute fibre properties,viz. linear density,mechanical properties,and fibre staple length were analyzed in this paper. Morphology,lignin content,and composition analysis for jute fibres were investigated in order to give further understanding of the fibre properties changing during the chemical treatment and yarn producing processes. The results show that jute properties are greatly changed during the processes of chemical treatment,breaking carding,and finisher carding,whereas slight changes can be found in the processes of drawing,roving,and spinning.

Analysis and Discussion of Fiber Motion in the Spinning Triangle of Ring Spinning

In order to analyze the effect of the spinning triangle on yarn structure,a shape model of the spinning triangle is established.The fiber motion in the spinning triangle can be divided into three stages,and the relationship between yarn structure and fiber duration as well as the force acting on the fibers in the three stages is analyzed.The fiber elongation in different location of the spinning triangle is variational.The difference is that the elongation of fiber in the middle spinning triangle is bigger than that in the edge of it and the difference will be amplified with the increase of spinning triangle width,which has an effect on the characteristic of yarns structure.Research results for further study on compact yarn structure and improving spinning frame structure provide theory basis.

Computation and Measurement of Winding Tension in Ring Spinning

By studying the variations of balloon height and of wind-ing radius in any one winding layer of ring spinning, the formula for determining the winding tension in any layer is derived, and then the overall tension variation throughout all winding layers can be computed. A meth-od of measuring the winding tension is also introduced here, with the measured results agreeing with the com-puted ones, and so the reliable relationship between winding tension, speed and ring traveller weight can be thus obtained. The highest allowable spindle speed is also discussed.

Rieter Presents A New Ring Spinning Machine at the ITMA ASIA in Shanghai

On their Stand B03in Hall W2at the ITMA ASIA+CITME2010in Shanghai,Rieter will present the new G32ring spinning

环锭纺纱新技术—EliTe Spinning

环锭纺尽管早已是一种非常成熟的纺纱技术 ,但是加捻三角区的存在仍然对成纱的质量具有一定的负面影响。该文介绍了一种全新的环锭纺纱技术 - Eli Te Spinning,在一定程度上消除了这些负面影响。

Thermal entanglement in molecular spin rings

The thermal entanglement in the triangular molecular spin ring with Dzyaloshinskii-Moriya interaction is studied. The concurrences of arbitrary two spins of the triangular molecular spin ring for various cases are evaluated. The tendency of the concurrence with Dzyaloshinskii-Moriya interaction and temperature is analysed and discussed. We note that the concurrence arrives at its maximum in the regime with the large Dzyaloshinskii-Moriya interaction and low temperature, and gradually decreases to zero with the increase of temperature. The concurrence has different features for the ferromagnetic and antiferromagnetic cases. For completeness, we also numerically calculate the concurrence of spin rings with N 〉 3 spins and analyse their behaviours.

Pure spin polarized transport based on Rashba spin orbit interaction through the Aharonov Bohm interferometer embodied four-quantum-dot ring

The spin-polarized linear conductance spectrum and current–voltage characteristics in a four-quantum-dot ring embodied into Aharonov–Bohm （AB） interferometer are investigated theoretically by considering a local Rashba spin–orbit interaction. It shows that the spin-polarized linear conductance and the corresponding spin polarization are each a function of magnetic flux phase at zero bias voltage with a period of 2π, and that Hubbard U cannot influence the electron transport properties in this case. When adjusting appropriately the structural parameter of inter-dot coupling and dot-lead coupling strength, the electronic spin polarization can reach a maximum value. Furthermore, by adjusting the bias voltages applied to the leads, the spin-up and spin-down currents move in opposite directions and pure spin current exists in the configuration space in appropriate situations. Based on the numerical results, such a model can be applied to the design of a spin filter device.

Spin transport in a chain of polygonal quantum rings with Dresselhaus spin-orbit coupling

Using a transfer matrix method, we investigate spin transport through a chain of polygonal rings with Dresselhaus spin-orbit coupling（DSOC）. The spin conductance is dependent on the number of sides in the polygons. When DSOC is considered in a chain which also has Rashba spin-orbit coupling（RSOC） of the same magnitude, the total conductance is the same as that for the same chain with no SOC. However, when the two types of SOC have different values, there results a unique anisotropic conductance.

Spin-polarized quantum transport through an Aharonov-Bohm quantum-dot-ring

In this paper the quantum transport through an Aharonov-Bohm （AB） quantum-dot-ring with two dot-array arms described by a single-band tight-binding Hamiltonian is investigated in the presence of additional magnetic fields applied to the dot-array arms to produce spin flip of electrons. A far richer interference pattern than that in the charge transport alone is found. Besides the usual AB oscillation the tunable spin polarization of the current by the magnetic flux is a new observation and is seen to be particularly useful in technical applications. The spectrum of transmission probability is modulated by the quantum dot numbers on the up-arc and down-arc of the ring, which, however, does not affect the period of the AB oscillation.

Transport properties in a multi-terminal regular polygonal quantum ring with Rashba spin-orbit coupling

Transport properties in a multi-terminal regular polygonal quantum ring with Rashba spin-orbit coupling （SOC） are investigated analytically using quantum networks and the transport matrix metLod. The results show that conduc- tances remain at exactly the same values when the output leads are located at axisymmetric positions. However, for the nonaxisymmetrical case, there is a phase difference between the upper and lower arm, which leads to zero conductances appearing periodically. An isotropy of the conductance is destroyed by the Rashba SOC effect in the axisymmetric case. In addition, the position of zero conductance is regulated with the strength of the Rashba SOC.

THE PRACTICE OF ROTOR SPINNING IN PRODUCING SILK NOIL YARN AND THE DEVELOPMENT IN WOVEN FABRICS AND KNITTED GOODS

At present, we have succeeded in producing silk noil yarn by rotor spinning, and obtained good economic benefits. In this paper, through combining with the recent producing practice, systematically discussing and analysing the technology in the process of producing silk noil yarn by rotor spinning, we develop the new technology which is suited to produce silk noil yarn by rotor spinning, and address several noticable problems. The conclusions have been put into practice and proved to be effective and reliable. It can be consulted by the textile mills.

Spin flip in single quantum ring with Rashba spin–orbit interation

We theoretically investigate spin transport in the elliptical ring and the circular ring with Rashba spin-orbit interaction. It is shown that when Rashba spin-orbit interaction is relatively weak, a single circular ring can not realize spin flip, however an elliptical ring may work as a spin-inverter at this time, and the influence of the defect of the geometry is not obvious. Howerver if a giant Rashba spin-orbit interaction strength has been obtained, a circular ring can work as a spin-inverter with a high stability.

Polarized spin transport in mesoscopic quantum rings with electron phonon and Rashba spin-orbit coupling

The influence of electron-phonon （EP） scattering on spin polarization of current output from a mesoscopic ring with Rashba spin-orbit （SO） interaction is numerically investigated. There are three leads connecting to the ring at different positionsl unpolarized current is injected to one of them, and the other two are output channels with different bias voltages. The spin polarization of current in the outgoing leads shows oscillations as a function of EP coupling strength owing to the quantum interference of EP states in the ring region. As temperature increases, the oscillations are evidently suppressed, implying decoherence of the EP states. The simulation shows that the magnitude of polarized current is sensitive to the location of the lead. The polarized current depends on the connecting position of the lead in a complicated way due to the spin-sensitive quantum interference effects caused by different phases accumulated by transmitting electrons with opposite spin states along different paths.

Spin transport properties of a Dresselhaus-polygonal quantum ring

We propose a theoretical method to investigate the effect of the Dresselhaus spin–orbit coupling（DSOC） on the spin transport properties of a regular polygonal quantum ring with an arbitrary number of segments. We find that the DSOC can break the time reversal symmetry of the spin conductance in a polygonal ring and that this property can be used to reverse the spin direction of electrons in the polygon with the result that a pure spin up or pure spin down conductance can be obtained by exchanging the source and the drain. When the DSOC is considered in a polygonal ring with Rashba spin–orbit coupling（RSOC） with symmetric attachment of the leads, the total conductance is independent of the number of segments when both of the two types of spin–orbit coupling（SOC） have the same value. However, the interaction of the two types of SOC results in an anisotropic and shape-dependent conductance in a polygonal ring with asymmetric attachment of the leads. The method we proposed to solve for the spin conductance of a polygon can be generalized to the circular model.