Browsing by Author "Ibrahim, Sayed M."
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- ItemApplication of Air in Yarn Production (Ring-Jet and Air Jet Spinning)(Technická Univerzita v Liberci, 2010) Sheolal, Ashwin; Ibrahim, Sayed M.The primary factors influencing the properties and character of staple spun yarns are fiber type and yarn structure. The particular spinning system, each producing yarn of its own distinctive character, determines the yarn structure. The spinning system is in turn dependent upon the manner in which twist is inserted. The recent trend is to use air-jets to insert twist producing yarn of a distinctive, unique structure, consisting of a core and belt or wrapper fibers. Yarn hairiness associated with the longer protruding fibers has been also reduced as a result of this structure. The use of air-jets in the production of yarn therefore has immense potential and is therefore a worthy field of research. An experimental study using compressed air, delivered by an air-jet, to the fiber stream upon exit from the front roller nip, in an attempt to assemble the fibers into a yarn structure, was conducted. The investigation was divided into the following: ? Ring-Jet Spinning Consolidating the fibers after drafting using an air-jet by applying false twist to the fibers, and thereafter applying real twist by a spindle on a conventional ringframe. ? Preliminary investigation into use of air-jets to produce yarn 1. An arrangement of two jets in series with two ancillary fiber tubes. 2. An arrangement of two air-jets in parallel and the third in a series to the first two to produce yarns similar to siro-spun. For ring-jet spun yarns, the influence on the following yarn parameters was determined, viz. yarn hairiness using Uster and Zwiegle testing equipment, yarn evenness and imperfections determined on Uster and yarn tensile properties on the Instron tester, for the ring- jet yarns.
- ItemCharacterization of Yarn Diameter Measured by Different Systems(Technická Univerzita v Liberci, 2010) Mvubu, Mlando Basel; Ibrahim, Sayed M.This thesis work tries to establish ways of comparing yarn diameter measurement values obtained from different measuring systems particularly Uster Tester 4 and QQM 3 as attempts have been made in the past to try and correlate the results from these two instruments. The work will also try and further investigate the versatility of the D-Yarn program in analyzing yarn diameter (and its variations) data compared to other similar analyzing systems. Yarn diameter and its variations together with hairiness were measured and compared accordingly, using various instruments and systems and from there, conclusions were drawn as to the comparability (correlation) of the results from these instruments.
- ItemDetermining the light transmission of woven fabrics through different measurement methods and its correlation with air permeability(Technická Univerzita v Liberci, 2014) Haleem, Noman; Ibrahim, Sayed M.; Hussain, Tanveer; Jabbar, Abdul; Malik, Mumtaz Hassan; Malik, Zulfiqar AliThe study aims to present a relationship between air permeability of woven fabrics and their light transmission properties. Polyester / cotton (48:52) blended woven fabrics were utilized in the study. Air permeability is measured using the standard test method already established while the light transmission through the fabric is measured by means of two different methods. One method is based on measurement of light transmitted from a back lit fabric by means of a light sensor. The second method is based on image processing techniques which require a digital back lit image of fabric and an algorithm is applied to measure the amount of light transmitted through it. Results from both methods are compared and correlated with the air permeability and porosity of woven fabrics. Analysis shows that the results from former method have a stronger and more significant relationship with air permeability of woven fabrics comparatively. © 2014, Association Nonwoven Fabrics Industry. All rights reserved.
- ItemMetodika hodnocení chlupatosti předenoskaných a skaných přízí(Technická Univerzita v Liberci, 2008) Krupková, Veronika; Ibrahim, Sayed M.This B.Sc, document deals with the evaluation of hairiness of produced by different production technologies. These are classical ring, plied and Siro-spun yarns. Importance of hairiness, definition and description of measuring instruments are discussed. The experimental part is directed to the analysis of data obtained from Uster Tester 4 and Zweigle G567 hairiness meter. Distribution of hairiness data obtained from Uster Tester 4 in evaluated by standard method, where unimodal distribution is applied. But statistical tests achieve, that the distribution of hairiness is bimodal (i.e. two Gaussian distribution together). This gives us more precise information about the distribution of both yarn hairiness components. Data obtained from Zweigle G 567 is fitted to exponential function, thus we can find the probability of occurring of any arbitrary hair length. At the and of this work a trial was made to find out any correlation between the data obtained from both instruments applyin a correlation matrix. It could not found any significant correlation between the data measured on both instruments.
- ItemThe optimization of experimental parameters for jet-ring spinning(Technická Univerzita v Liberci, 2012) Zhu, Guocheng; Ibrahim, Sayed M.; Křemenáková, DanaThe application of air-jet nozzle in ring spinning system has been turned up in the last decade, and the greatest advantage reported is the reducing of hairiness. In this paper, an attempt has been made to optimize the utility of a single air-jet nozzle in ring spinning system. Some parameters, such as air pressure, the distance between front roller nip line and air-jet nozzle inlet, and the number of orifices were adjusted to get a better quality yarn. In order to confirm the role of these parameters, the properties of ring and jet-ring spun yarns were compared. All the samples were characterized in terms of count, twist, irregularity, hairiness and strength. The results showed that the air pressure and the distance have a significant influence on irregularity; all the experimental parameters have a significant influence on hairiness. By multi-objective programming method, a set of optimal experimental parameters was found, and the properties of jet-ring spun yam were improved significantly.
- ItemSimulation of airflow motion in jet nozzle with different geometric parameters(Trans Tech Publications Ltd, 2013) Zhu, Guocheng; Ibrahim, Sayed M.; Militký, Jiří; Wang, Yan; Křemenáková, DanJet nozzle with tangentially injected airflow has been applying into spinning technology due to the tangential force produced by swirling airflow. In order to understand the airflow motion trajectory in jet nozzle, modify the nozzle structure and dimension, FLUENT software program is used. Some parameters which are closely related the airflow motion profiles are studied, such as the diameter of nozzle chamber, the diameter and angle of the orifice. The results showed that the intensity of air swirling is more strong in a smaller nozzle chamber; a larger orifice diameter is helpful for producing strong yarn and improving production efficiency, but it requires a larger nozzle chamber, therefore, a reasonable rate of orifice and nozzle chamber diameter is important; as the orifice angle increases, the tangential velocity decreases, which decreases the intensity of airflow swirling, and a small orifice angle will cause a larger reverse jet, which is bad to draw the fibers into the nozzle. © (2013) Trans Tech Publications, Switzerland.