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.

Color-matching model of digital rotor spinning viscose mélange yarn based on the Kubelka–Munk theory

The color-matching model is conducive to expanding the scope of application of colorful fabrics and can speed up the achievement of intelligent production. To solve the problem in which the existing color-matching system of intelligent colored spun yarn cannot be applied to the digital rotor-spinning products of dope dyed viscose fiber, 66 types of mélange yarn were spun with a digital rotor-spinning frame using red, yellow, and blue dope dyed viscose fibers at a ratio gradient of 10%. Furthermore, the knitted fabric samples were produced using a circular machine. Meanwhile, a Datacolor 650 spectrophotometer was used for color testing, and the experimental results were recorded. Based on the color-matching model of the Kubelka–Munk theory, a color-matching model is built based on the experimental results. In addition, the accuracy of the model was analyzed and verified using the least-squares and relative value methods. The results show that, compared with the relative value method, the color-matching model constructed using the absorption coefficient K value and scattering coefficient S value calculated based on the least-squares approach is more accurate. The error between the predicted ratio of the test sample and the actual ratio was only 0.0979, the average color difference was only 0.465, and there were no visible differences between the predicted color of the sample and the actual color.

Effect of silicone based softener on fabric handle properties made by ring, rotor and MVS yarns

Purpose The purpose of this study was to produce yarns from three different spinning techniques, i.e.Murata Vortex Spinning (MVS) ring spinning and rotor spinning. Those yarns were then used to produce fabrics. Then, the effect of silicone softener on tactile comfort of fabric was investigated. Design/methodology/approach Three different yarns, i.e. Ring, Rotor and MVS yarns, were used to make fabrics using CCI sample loom which were then subjected to post treatments like desizing, scouring and bleaching. After the completion of the dyeing process, silicone-based softener was used to improve the hand feel of fabrics. The structures of three yarns were evaluated using Scanning electron microscopy. The fabrics were evaluated against compression, bending and surface properties using Kawabata evaluation system. Findings The fabric made of MVS yarn depicted more geometrical roughness, coefficient of friction and bending rigidity but less compressibility as compared to fabrics made with other yarns. It was observed that softener concentration has a direct relationship with thickness and bending rigidity of the fabric, and inverse relationship with coefficient of friction and geometrical roughness of the fabric. Originality/value MVS yarn has some superior properties over rotor and ring spun yarn like high production rates, high resistance to pilling, clear appearance and stability against deformation but has disadvantage that it has less compressibility. Therefore, softener is applied on the fabric, to address this issue, so that it could also be used for apparels application.

Investigation of Influence ofa New Twist Intensifier on the Properties of the Twisted Yarn

The article is devoted to the study of the properties of the yarn obtained by the methods of ring and rotor spinning, for twisted yarn, produced on a VTS-09 double twist machine made by Volkmann (Germany). Experiments were carried out on two typesof spinning yarns with yarn counts Ne 20/2 and 12/2 in the existing design (control) and the new design, flexible element with equal tension and twist intensifier and compared the effects of the resulting twisted yarn for quality parameters. Mathematical statistical methods (single-factor analysis of variance) were used to assess the quality of twisted yarn. Experiments have shown that the use of a new design nozzle reduces the vibration of the yarn, which leads to a uniform distribution of twists along the length of the twisted yarn, increases its tensile strength and improves the quality of the twisted yarn.

Effect of position of the fiber transport channel on fiber motion in the high-speed rotor

The task of the fiber transport channel (FTC) is to transport the fibers from the carding roller to the rotor. Its geometric position in the spinning machine has a strong influence on the characteristics of the airflow field and the trajectory of the fiber motion in both the rotor and the FTC. In this paper, a three-dimensional pumping rotor spinning channel model was established using ANSYS-ICEM-CFD software with three different positions of the FTC (positions a–c). Further, the simulations of air distribution were performed using Fluent software. In addition, the discrete phase model was used to fit the fiber motion trajectory in the rotor. The simulation results showed that among the three types of FTC, position b is the optimal condition. The gradients of airflow velocity in the channel at position b were greater than those of the other two positions, which is conducive to straightening of the fiber.

The pattern design of fabrics produced by three-channel rotor-spun colorful melange yarn

PurposeThe purpose of this article is to design and make fabrics with colorful melange yarns spun by a three-channel rotor spinning machine.Design/methodology/approachThe three-channel digital rotor-spun machine controls the blending proportion by adjusting the feeding of three-primary color fiber slivers online, so that a piece of colorful yarn presents a variety of colors along the longitudinal direction where constant yarn linear density can be produced flexibly. Various fabric patterns can be produced by three-channel rotor-spun colorful melange yarn with different periods of color.FindingsThe fabric, made by the rotor-spun colorful melange yarn, is rich in color, clear in layers, soft in the hand and has a hazy three-dimensional effect. The product is environmentally friendly and saves energy.Originality/valueAn innovative idea to develop various colorful fabrics is proposed by combining their pattern with colorful melange yarn produced by a three-channel rotor spinning machine.

Optimization Issues of a Hammer Mill Working Process Using Statistical Modelling

Our paper presents the hammer mill working process optimization problem destined for milling energetic biomass (MiscanthusGiganteus and Salix Viminalis). For the study, functional and constructive parameters of the hammer mill were taken into consideration in order to reduce the specific energy consumption. The energy consumption dependency on the mill rotor spinning frequency and on the sieve orifices in use, as well as on the material feeding flow, in correlation with the vegetal biomass milling degree was the focus of the analysis. For obtaining this the hammer mill was successively equipped with 4 different types of hammers that grind the energetic biomass, which had a certain humidity content and an initial degree of reduction ratio of the material. In order to start the optimization process of hammer mill working process, 12 parameters were defined. The objective functions which minimize hammer mill energy consumption and maximize the milled material percentage with a certain specific granulation were established. The results obtained can serve as the basis for choosing the optimal working, constructive, and functional parameters of hammer mills in this field, and for a better design of future hammer mills.