Search results

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.

Spun silk is one of the top grade textile materials, and its products have high added value and meet the needs of the market. However, the technology level and process design of silk spinning are still much lower than cotton spinning; especially singeing is applied on spun silk yarn, and generates waste materials. The purpose of this paper is to introduce a kind of pneumatic compact spinning, four-line compact spinning (FLCS), into silk spinning and study the corresponding spun yarn qualities.

First, taking the silk spinning frame FK501 as an example, the process of modification of FLCS is presented. Then, three kinds of spun silk yarns, 80 Nm (12.5tex), 100 Nm (10tex) and 120 Nm (8.3tex), are spun on the common silk spinning frame FK501 and the spinning frame modified with FLCS. The evenness, breaking strength and hairiness of spun yarns are tested and comparatively analyzed. After the ply yarn production, three singeing procedures should be applied on the ring ply yarns, while only two singeing procedures should be applied on the compact ply yarns, which is beneficial for material saving.

The results show that compared with ring spun silk yarns, the comprehensive quality of compact spun silk yarns is improved, especially the harmful long hairiness (=3 mm) of yarn. Compared with the single spun silk yarn, the comprehensive qualities of the ply yarn are improved; especially, the breaking strength of the ply yarns is two times larger than the single yarn. After singeing, the hairiness of the ply yarn is decreased greatly, and the evenness is also improved, while the strength is decreased. Compared with ring spun silk yarn, the singeing times of compact spun silk yarn can be decreased, and the gas consumption in each singeing is also decreased, which is beneficial for material saving.

In this paper, a kind of pneumatic compact spinning, FLCS, is introduced into the silk spinning. It is shown that compared with ring spun silk yarns, the comprehensive quality of compact spun silk yarns is improved, especially the harmful long hairiness (=3 mm) of yarn. After the ply yarn production, three singeing procedures should be applied on the ring ply yarns, while only two singeing procedures should be applied on the compact ply yarns, which is beneficial for material saving.

Presents the mechanical models of ring, rotor and air‐jet staple yarn formation. The analysis of formation peculiarities has enabled the establishment of differences among them in micro‐ and macrostructure as well as in their mechanical and physical properties. The comparison of yarn and fabric quality parameters will be very valuable for weavers, knitters, garment manufacturers, finishers and designers. Gives productivity, spinability and economic factors for ring spinning, OE‐rotor and air‐jet spinning processes.

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 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.

The purpose of this study is to investigate the mechanical properties of denim fabrics constructed from ring-spun and open-end rotor spun yarns.

Yarns of 10s Ne count using cotton fibers were spun using the ring and open-end rotor spinning technologies. The yarns were used to produce a denim fabric on an air-jet loom with a 3/1 twill weave structure. Mechanical tests – tensile strength, tear strength, abrasion resistance and pilling resistance – of denim fabrics were evaluated. The test results were analyzed using analysis of variance with the help of Software Package for Social Sciences.

Denim fabrics made by using ring-spun yarns exhibited better tensile and tear strength properties than denim fabrics made by using open-end rotor spun yarns. On the contrary, denim produced using open-end rotor yarns have better abrasion resistance, pilling resistance and air permeability than those produced using ring-spun yarns.

Both spinning techniques have a significant influence on the properties of denim fabrics. Whenever better tensile and tear strength is required, it is better to use ring-spun yarns, while if the requirement is better abrasion resistance and pilling resistance with high air permeability, then open-end rotor spun yarns shall be used.

The purpose of this paper is to theoretically study the effects of ring spinning triangle division on spun yarn torques.

The case that the spinning triangle is divided into two parts, primary triangles and final triangle, is investigated. Theoretical model of yarn torque was given by linking the fiber tension in the spinning triangle to yarn torque under the assumption that the arrangement of fibers (substrands) in the substrands (yarn) is hexagonal close packing. Then, as an application of the proposed method, 14.6tex cotton yarns were taken as an example for the numerical simulations.

The fiber tensions in the divided spinning triangles and corresponding yarn torques were simulated numerically by using MATLAB software. The effects of division proportions and number of primary triangles on spun yarn torques are analyzed theoretically.

It is shown that suitable spinning triangle division is benefit for reducing yarn torque.

Spinning triangle is a critical region in the spinning process of staple yarn, which geometry influences the distribution of fiber tension and determines the qualities of yarn directly. Therefore, the purpose of this paper is to investigate the fiber tension distribution at the twist point.

First, one theoretical model of fiber tension distributions at the twist point is given according to the motion law of fibers in the spinning triangle. Then, one calculation method of fiber tension at the twist point is given by two steps. First, the initial tension of each fiber at the front nip line caused by the yarn load should be calculated according to the models obtained based on the principle of minimum potential energy. Second, the fiber tensions at the twist point can be calculated using the obtained model in this paper. Finally, as an application of the proposed method, spinning triangles of a modified ring spinning system with a pair of offset device which can change the horizontal offset of the twist point to the symmetric axis of nip line of the spinning triangle continuously are studied. The fiber tension distributions are simulated numerically.

It is shown that the fiber tension distributions at the twist point can be determined by fiber feeding into and out the spinning triangle speed, the initial tension of each fiber at the front nip line, fiber tensile Young’s modulus and cross-sectional area, the number of fibers at spinning triangle and the individual fiber angle with the center fiber. The spinning experiment shows that taking appropriate right or left offset of the spinning triangle can help to improve the spun yarn qualities.

In this paper, the fiber tension distribution at the twist point is investigated. One theoretical model of fiber tension distributions at the twist point is given according to the motion law of fibers in the spinning triangle first. Then, one calculation method of fiber tension at the twist point has been given under the assumption that the initial tension of each fiber at the front nip line is caused by the yarn load.

Dref-3 friction spun core yarns produced using staple fibre yarn as the core, e.g. Jute core yarn wrapped with cotton fibre, have poorer mechanical properties compared to the core yarn itself. The purpose of this study was to understand the structure of such yarns, that will lead to the optimization of fibre, machine and process variables for production of better quality yarn from the Dref-3/3000 machines.

The Dref spinning trials were conducted following a full factorial design with six variables, all with two operative levels. The Dref-3 friction spun yarn, in which the core is a plied, twisted ring yarn composed of cotton singles and the sheath, formed from the same cotton fibres making the singles, has been examined. The structures have also been studied by using the tracer fibre technique.

It was observed that rather than depending on the plied core yarn, the tensile properties of the Dref-3 yarn are significantly determined by the parameters those affect the constituent single yarn tensile properties, i.e. the amount of twist and its twist direction, yarn linear density and the sheath fibre proportion used during the Dref spinning in making the final yarn. Further, when the twist direction of single yarn, double yarn and the Dref spinning false twisting are in the same direction, the produced core-sheath yarn exhibits better tensile properties.

The understanding of the yarn structure will lead to optimized production of all staple fibre core Dref spun yarns.

The research work may lead to utilization of coarse and harsh untapped natural fibres to the production of value-added textile products.

Though an earlier research has reported the effects of sheath fibre fineness and length on the tensile and bending properties of Dref-3 friction yarn, the present study is the first documented attempt using the tracer fibre technique to understand Dref-3 yarn structure with plied staple fibrous core.

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.