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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.

The purpose of this study is to investigate the effects of air-suction slots geometry on the condensing zone of pneumatic compact spinning.

This paper investigated the condensing zone of pneumatic compact spinning with perforated drum for different structures of air-inlet slot geometry with computational fluid dynamics. For this purpose, three air-suction guides with different air-slots were designed. To create the condensing zone for the numerical simulation, a suction insert and the perforated drum were also designed. Flow velocity components on the X, Y, and Z axes, static pressure distribution and the streamline diagram were used for comparative analysis. Designed air-suction guides were produced with a 3D printer and used for yarn production.

Numerical simulation results showed that condensing effects were provided for all three types of air-suction guides and approaching air-slots on the suction guides resulted in greater flow components but may cause fluctuations. Experimental results also showed that actual flow velocity components (Z-axis) are effective on hairiness (H) properties of the yarn while assisting flow-velocity components are more effective on the evenness and tenacity properties of the yarn.

This paper presents the numerical flow field simulation of compact spinning for different structures of air-suction guides with detailed measurements. To know the effects of air-suction guides on the condensing zone may be helpful to improve yarn properties. In addition, a 3D printer was used for the production of designed parts.

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.

As a natural fiber, yakwool has attracted much attention in textile processing due to its excellent properties and wearabilities. However, the main colors of yakwool are black and brown. Therefore, for extending the application scopes of the fiber, the decolorization of the yakwool fiber is usually needed, especially for the black fiber. The paper aims to discuss this issue.

In the paper, the properties of the yakwool fiber were tested first, especially the melanin granules in the fiber. Then, the decolorization of the yakwool fiber was studied using the oxidation–reduction decolorization method, and corresponding optimal process of the decolorization was given. Then, the properties of the decolorized yakwool fiber were tested and compared with those of the original fiber.

It is shown that, after decolorization, the physical and mechanical properties of the fiber were deteriorated, especially in terms of the strength and elongation. Therefore, the fiber became shorter and thinner, and the scales were damaged. When compared with the yarn spun from the original yakwool fiber, it was observed that the properties of the yarn spun from the decolorized yakwool fiber deteriorated because of the deterioration in the properties of the original fiber.

In the paper, for extending the application scopes of the yakwool fiber, the decolorization of the yakwool fiber was studied.

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.

Condensing roller is the most key parts of compact spinning system. Hollow Roller is one of the most important kinds of condensing roller, the surface structure of which influences the flow field in condensing zone directly and affects the qualities of spun yarn. The purpose of this paper is to study the effect of Hollow Roller surface structure on flow field in condensing zone is investigated by using Fluent Software.

In this paper, the effect of Hollow Roller surface structure on flow field in condensing zone is investigated by using Fluent Software. The numerical simulations of the three-dimensional flow field in Hollow Roller compact spinning with two different kinds of roller surface structure, round hole structure and strip groove structure, are given according to the three-dimensional physical model of condensing zone. The flow velocity and static pressure distributions in condensing zone are given.

It is shown that the flow velocity streamline distribution is denser with strip groove structure than that of round hole structure, especially on the center line of strand, and flow velocity value is also larger in both Y-Z and X-Y cross-sections, and in X-Z cross-section shows the embracing inlet airflow, which is benefit for fiber condensing directly and improving negative pressure use efficiency. Furthermore, the simulations with three strip groove widths 0.4, 0.8 and 1.2 mm are given. The theatrical results obtained are illustrated by experiments.

In this paper, the effect of Hollow Roller surface structure on flow field in condensing zone is investigated by using Fluent Software in detail. A more accurate three-dimensional physical model of condensing zone is given. A new kind of strip groove structure of Hollow Roller is proposed. The theatrical results obtained are illustrated by experiments, and lay a foundation for practical Hollow Roller design.

In order to develop high shape retention yarn and investigate the effects of spinning process and core yarn contents on the shape retention of yarn, in this paper, three kinds of yarns, JC/T400 18.5tex (55.6dtex) core-spun yarn, JC/T400 18.5tex (44.4dtex) core-spun yarn and JC18.5tex pure cotton yarn were spun by using the complete condensing Siro-spinning technology. The paper aims to discuss these issues.

In this paper, the core-spun yarns were spun by using the complete condensing spinning and Siro-spinning technology. Two key spinning processes, yarn twist factor and core yarn pre-draft ratio, were optimized by using the orthogonal test method first. Then, via the variable control method, the position of the core yarn, the position of the bell mouth and the center distance between two bell mouths were optimized, respectively, and corresponding optimal spinning process of the three yarns was determined. Finally, the yarns were spun under the optimal process, and the performance of the spun yarns was tested and compared.

Results show that the yarn twist factor affects yarn strength and hairiness, the position of bell mouth affects the evenness and hairiness of the yarn mainly, and the position of the core yarn affects the coverage and hairiness of the yarn. For the Z-twist spinning, the core yarn enters the front roller from the left side of two strands center, which is beneficial to improve the covering effect of core yarn, and reduce the pilling phenomenon of the yarn. The contents of core yarn affect indicators of the yarn shape retention, such as yarn strength, elastic recovery and abrasion resistance.

The shape retention of yarns affects the shape retention of fabrics, and the production of yarn with high shape retention is a key step in achieving shape retention of fabrics. At present, there are little studies on the shape retention of yarns, most researchers shave focused on shape retention of fabrics. Using the complete condensing Siro-spinning method to spin the core-spun yarn can improve the quality of the yarn. Compared with traditional ring-spinning yarns, the addition of the core yarn can improve the shape retention of the yarn.

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.

Examines the tenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

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.