Effect of Spinning Triangle and Production Speed of Hollow-Spindle System on the Bouclé Yarn Structure

This study aims to show the impact of both the width of the base of the spinning triangle and the production speeds of hollow-spindle spinning machines on the structure of ultimate multiple-thread-structure bouclé yarns and similar fancy yarns. A hollow-spindle spinning machine was used and bouclé yarns were made of a core thread, an effect thread and a (multifilament) binder. Initially, five bouclé yarns were made by setting the widths of the base of the spinning triangle at five levels, i.e. 4.5 mm, 7.5 mm, 10 mm, 13 mm and 16 mm. A further six bouclé yarns were made to show the changes that occur to the spinning triangle at various production speeds. The resulting fancy bouclé yarns were assessed by measuring the size, number and circularity ratio of bouclé profiles. It was found that at low production speeds, i.e. at start-up, that the spinning triangle was unstable, which adversely affected the structure of the final bouclé yarns. However, at production speeds higher than 17 m/min, the spinning triangle became stable, though such a stable spinning triangle had no impact on the structure of the resulting fancy bouclé yarns. The results of this study may help fancy yarn manufacturers to avoid making defective fancy yarns.

Comparison of the airflow characteristics and yarn properties between conventional and dual-feed-opening rotor spinning units

In order to explore the differences between conventional and dual-feed-opening rotor spinning units (RSUs), this work compares the airflow characteristics of two RSU models utilizing a computational fluid dynamics simulation model with the accuracy verified by airflow behavior observation and air pressure measurement. The effect of two different opening roller speeds on the airflow field distribution of a dual-feed-opening model is also investigated. In addition, the yarn properties of six pure and blended yarns corresponding to the two RSU models are evaluated. The results reveal that the distributions of airflow velocity vector and air pressure in the two RSU models show a strong similarity under the same boundary conditions. However, the dual-feed-opening model possesses a centrosymmetric and more balanced airflow field distribution compared to the conventional model. In addition, the dual-feed-opening yarns show a superior performance in comparison to the conventional yarns. Furthermore, for the dual-feed-opening model, there are equivalent contributions of two separated opening and fiber transmission systems to the airflow field distribution and yarn formation. Compared to the configuration with the same two opening roller speeds, the dual-feed-opening model configured with two different opening roller speeds obtains an improved blended yarn performance with having few effects on the airflow characteristics. This strength of the dual-feed-opening RSU could facilitate the production of blended and fancy yarns employing the fibers with diverse properties. This study could provide some guidelines for the manufacture of rotor-spun yarns and the future design of RSUs.

Permeability properties of woven fabrics containing two-ply fancy yarns

The basic intention of the presented research is to analyse the permeability properties of woven fabrics containing two-ply fancy yarns in the weft direction. Within the framework of presented research, two-ply fancy yarns were analysed. Because of their structure, they are classified as fancy yarns with structural effects. The first analysed two-ply fancy yarn is made of the mixture of 81% cotton and 19% viscose. The second is made of the mixture of 67% viscose and 33% flax. For the purpose of the presented research, woven fabrics containing two-ply fancy yarn were made in three different densities in weft (10 threads per cm, 13 threads per cm, and 16 threads per cm) in the twill weave T 1/3 Z. The theoretical part includes the historical development of the production of the fancy yarns, a detailed discussion of the ring production processes, the types and the structure of the fancy yarns, their use, and the global and European market of the fancy yarns. The experimental part consists of three parts. In the first part, the structural properties of the analysed fancy yarns were researched (the fineness of the fancy yarn, the frequency of repeating the effects per one meter of the yarn, the direction of twisting the fancy yarn, the number of the twists of the basic and the effective part, the diameter of the fibers, the diameter of the basic and the effective part, the fineness of individual components, the direction of the twist of individual components, and the percentage of the inside twist of individual components). In the second part, constructional properties of the analysed woven fabrics with the fancy yarn in the weft were researched (mass, thickness, the density of the warp and weft threads, and openness of the surface). In the third part, permeability properties of the analysed woven fabrics with the fancy yarn in the weft were researched where greater attention was paid to air permeability and water vapour permeability. The results of the research showed that the samples with the first two-ply fancy yarn in the weft (81% cotton and 19% viscose) have greater air permeability and water vapour permeability. Meanwhile, the samples with the second two-ply fancy yarn in the weft (67% viscose and 33% flax) have lesser abrasion resistance and poorer dimensional stability while being washed.

Appearance change for colored spun yarn fabric based on image color transfer

The fabric of colored spun yarn has ever-changing appearances and styles with different fancy yarns. The fabric image is commonly designed by the designer using the software, which needs complex user interactions and difficult image segmentation. In this paper, a modified color transfer method was proposed to generate the fabric appearance of colored spun yarn. Given the color card as the target image, the style fabric image was matched as the reference image based on the dominant luminance. After transferring the two images to lαβ color space, Wavelet transform and luminance sampling were utilized to filter the redundant high-frequency information and select the representative pixels, respectively. Then, the chromatic channels were transferred based on the best matched luminance and the neighborhood relation. Finally, the image after color transfer was reconstructed by wavelet reconstruction. The proposed reference image matching maintained the result to be the ground truth. For the samples selected, the combined methods based on wavelet transform and luminance sampling improved the efficiency and performance of the proposed scheme. Experiments were conducted on different fabrics with different colors and styles. Experiments demonstrated the validity and superiority of the proposed method, which can provide referential assistance for the designer and save considerable amounts of labor.

Texture features extraction of multi-coloured fancy yarn

In the present work, a framework of extracting important texture features of multi-coloured fancy yarns is proposed. Aself-developed image capturing apparatus is used to record the image of fancy yarn. Subsequently, the captured digitalimages are processed to produce spatially corresponding pixel points to reconstruct digital images of the object,including image greying, filtering and morphology processing. At last, different segmentation methods are used to extractthe texture features of fancy yarns, and the optimal segmentation method to each kind of fancy yarn is analysed.

Experimental study on the spinning geometry of multi-thread fancy yarn on hollow-spindle spinning machines

Purpose The purpose of this paper is to define the relationships between the structure of multi-thread fancy yarns and the combination of the rotational speed of the hollow-spindle spinning system and thickness and stiffness of the effect component. Design/methodology/approach To do so, two groups of fancy yarns were made using stiff and soft effect threads and at six different machine settings. Findings It was found that the stiff effect thread was suitable to make fancy yarns at low rotational speeds, while the thickness of the effect threads was more important than its stiffness at low number of wraps. Additionally, even when using the same number of wraps and the overfeed ratio, a bouclé yarn, a gimp yarn, a wavy yarn or a loop yarn may results if the thickness and stiffness of the effect thread and the rotational speed were all controlled properly. Originality/value This study helps fancy yarn spinners to determine the type of final fancy yarns by controlling the spinning geometry in the first spinning zone.

Study of maximum tensile strength of fancy yarns using the design of experiments

This study was conducted to identify the factors and the interactions which affect the maximum load of multi-thread fancy yarns. The objectives of this research was to identify the relative contribution of each factor and interaction leading to the maximisation of the tensile strength. The fancy yarns were made on a hollow-spindle spinning machine. The experimental design of this study had seven factors – with two levels each and was repeated five times. It was found that using two single yarns, instead of a similar two-ply yarn, for the core component increased the value of maximum load. The effect component contributed positively to the load only when it was a three-ply cotton yarn rather than a three-ply bamboo yarn since the former had interactions with the core and the binder. Excessive wraps reduced the maximum load. The effect of the overfeed ratio on the maximum load was weak. The manufacturing process in general had low levels of variability. This research is important because it contributes to a broader understanding to the effect of seven factors on the structure, quality, and mechanical properties of multi-thread fancy yarn.

Multisection color-blended wool yarn produced by a new three-channel spinning method

By dynamically controlling the feeding amount and feeding ratio of the three feeding rollers with program logical control system under the requirements of yarn spinning parameters, it is possible to effectively configure the final yarn density and the blending ratio of three components to produce multisegment gradient yarns, segment-color yarn, and segment-color slub yarn named as multisegment blending yarns. The yarn-spinning new method was proposed. Different kinds of fancy yarns including gradient yarns, segment color yarns, and slub yarns were produced. The fiber blending effects were demonstrated by slices of yarn cross section, and the surface morphology of yarns were figured out by the photo of yarns. Integrally knitting seamless sweater and different type of pattern were designed and knitted by multisegment blending yarns. The free change of colors along the length direction on a single yarn provides an effective method for integrated rapid design and production of sweaters through mutual design of the overall pattern and the structure of the fabric.

The influence of component stiffness on the structure of multi-thread fancy bouclé yarn

This study examines the relationships between the structure of fancy bouclé yarns and the bending stiffness of the input threads that are used to make those fancy yarns. Four fancy bouclé yarns and an extra two confirmation bouclé yarns were made to test the impact of the bending stiffness of the effect input threads. Six fancy yarns were made to test the impact of bending stiffness of the core thread on the fancy yarn structure. The structure of the fancy yarn was defined by the number of fancy profiles, the size of fancy profile, the circularity ratio of fancy profile and the shape factor of fancy yarn. It was found that increasing the value of the stiffness of the effect thread increased the size of fancy profile but decreased both the number of fancy profiles and the shape factor of fancy yarn. Those relationships were represented by regression models that were significant at α = 0.10. The deviation between the theoretical values and the real values was −14.39% and 2.07%. Further, up to a value of 8.636 g mm2, the bending stiffness of the core thread appeared not to have an effect on the structure of the fancy yarns. This study is important as it is the first that accounts statistically for the impact of bending stiffness of the input threads on the structure of the resultant fancy yarns. Therefore, it aids fancy yarn manufacturers when designing fancy yarns with predicted structures.