Bulent Ozipek

Comparing Dynamic and Static Methods for Measuring Thermal Conductive Properties of Textiles

Dynamic and a static methods for measuring thermal conductivity of textiles have been developed, and the measuring processes and results are described in detail in this paper. Three different textile materials are used for the actual test. and the data are analyzed, illustrated, and compared. Moreover, a theoretical model is used to obtain the temperature-time curves as predictions corresponding to the dynamic method, and comparisons of the theoretical predictions and experimental results are provided. The static and dynamic methods are also compared, and their applicability to porous media like textiles is discussed.

Investigation of Vortex Spun Yarn Properties in Comparison with Conventional Ring and Open-end Rotor Spun Yarns

In this study, the properties of ring, rotor, and vortex spun yarns produced in different counts from cotton, viscose rayon, and 50/50 cotton-modal blended fibers were investigated. Yarn samples were converted into knitted fabrics in a single jersey circular knitting machine and dyed with reactive dyestuff to determine the physical performances of the yarns in knitted form. The results revealed that vortex spun yarns have lower hairiness and better pilling resistance over ring and open-end rotor spun yarns. Furthermore, viscose rayon yielded more satisfactory results in the vortex spinning system in terms of yarn strength, particularly in coarser yarn counts and hairiness.

Thermo-Insulating Properties of Perpendicular-Laid Versus Cross-Laid Lofty Nonwoven Fabrics

The thermo-insulating properties of both perpendicular- and conventional cross-laid lofty nonwoven fabrics, four different types each in terms of fiber fineness, are investi gated using a new static method with a heat flux sensor. The relationship between the thermal conductivity and the material density of all the samples is studied, and the compressive behavior of the materials and changes in thermal resistance with compression are also evaluated. The effects of fiber fineness and material density are examined and discussed as well.

Influence of Varying Structural Parameters on Abrasion Characteristics of 50/50 Wool/Polyester Blended Fabrics

This paper reports an analysis of the influence of polyester and yarn type on the abrasion resistance of 50/50 wool/polyester blended woven fabrics. Recently developed polyester fibers put into the blend and two-strand Sirospun yams are compared with 2.5 denier standard polyester and two-fold ring yarns. Mass losses of ten fabrics abraded in the Martindale tester are obtained for eight abrasion levels and given in three groups of graphs in a comparative form. Regression analyses help describe mass loss ratios of fabrics as a function of abrasion cycles and other structural parameters. Linear and, in some cases, quadratic and cubic models help explain the acceleration in mass loss rates, and SEM photographs show surface degradation of wool blend fabrics.

Influence of varying structural parameters on the properties of 50/50 wool/polyester blended fabrics

This paper deals with the mechanical properties and air permeability of lightweight wool blend apparel fabrics. We have studied mechanical responses in uniaxial tensile and tear tests of gray-state fabrics, and low deformation characteristics (i.e., bending rigidity, shear rigidity, and extensibility) in FAST tests of finished fabrics. We also measure fabric drape coefficients and node numbers using Cusicks method and fabric air permeabilities. Effects obtained by changing polyester and yarn type are analyzed for three groups of fabrics with different constructions using a statistical approach and are found to be significant; however, using novel polyester with a special cross-sectional shape and varying fineness in the wool blend, we successfully obtain fabrics with low rigidities, better drape characteristics, and quite sufficient tensile and tear performance. The behavior of fabrics woven with Sirospun yams is quite satisfactory in many respects. Polyester and yarn type also significantly affect fabric air permeability.

The structure and properties of carded cotton vortex yarns

The properties and spinning limits of carded cotton vortex spun yarns were investigated through the progressive change in yarn count. The yarns were tested for structural and physical properties. Critical parameters were obtained, including the ratio of wrapper fibers to core fibers, proportion and average length of different structural classes in the yarn. The structural analysis revealed that the wrapper fibers constitute an increasing proportion of the fibers as the yarn becomes finer. Moreover, the proportion and average length of different structural classes in vortex spun yarns change with yarn count. The analysis of the data obtained from yarn testing showed that as the yarn becomes finer, the yarn becomes more uneven and the number of yarn imperfections markedly increase. On the other hand, the tensile properties of vortex spun yarns remain almost unchanged as the yarn gets finer.

Reuse of effluent water obtained in different textile finishing processes

Abstract: The use of clean water in textile finishing is both common and very expensive. Effluent water subjected to advanced methods of physical, chemical, and biological treatment could be used for this purpose. However, information obtained from industry and the literature shows that effluent water obtained from different finishing processes may be reused without being totally purified. In this paper, a method is proposed to determine the viability of reusing effluent water obtained from different textile finishing processes of cotton fabrics after just basic treatments. These treatments include; filtering, airing, pH regulating and ion exchange. Effluent water obtained in different textile finishing processes was analysed in terms of pH value, COD (Chemical Oxygen Demand), SS (Suspended Solids), colour, hardness and conductivity. Effluent water for treatment and the process where the treated water was reused were determined by means of the proposed method, based on a multiple criteria decision making approach. A laboratory scale trial was conducted to investigate the efficiency of treatment.

The impact of combing and processing parameters on the structure and properties of fine count vortex yarns

In this paper, the impact of short fiber content, yarn count and yarn delivery speed on the structure and properties of fine count cotton vortex yarns were investigated. The factors affecting the fine count yarn spinning on a vortex spinning system were determined on the basis of yarn structure and properties by using the linear regression technique. Moreover, the spinning limits of combed cotton vortex spun yarns were investigated. The results of the experiments revealed that the short fiber content in the cotton sliver is an important parameter in spinning fine count vortex spun yarns. The lower short fiber content in the sliver allows finer counts to be spun in the vortex spinning system. It was also observed that yarn delivery speed influences the yarn structure, and hence the yarn properties significantly, since it determines the residence time of the fibers in the yarn formation zone, and also affects the fiber control due to the air flow caused by the surface speed of the delivery rollers. In addition, the structure and properties of vortex spun yarns change significantly with regard to yarn count.

Effects of Fiber Properties of Acrylics on Rotor Spinning

An investigation is reported to determine which of the differences in properties of commercially available acrylic fibers are most important in influencing rotor spinning performance and ultimate yarn quality. A crushing test appeared to be a successful method to isolate the differences between acrylic fibers and to predict their processing behavior, Fiber damage and rotor deposit build-up were assessed when different acrylic fibers were spun, and some similarities were found between spinning behavior and yarn properties and the results obtained from the crushing test. Consequently, the different behavior of the fibers during rotor spinning was defined by the differences in fiber characteristics.An investigation is reported to determine which of the differences in properties of commercially available acrylic fibers are most important in influencing rotor spinning performance and ultimate yarn quality. A crushing test appeared to be a successful method to isolate the differences between acrylic fibers and to predict their processing behavior, Fiber damage and rotor deposit build-up were assessed when different acrylic fibers were spun, and some similarities were found between spinning behavior and yarn properties and the results obtained from the crushing test. Consequently, the different behavior of the fibers during rotor spinning was defined by the differences in fiber characteristics.

Effects of Assembly and Twisting Nozzle Pressures on the Properties of Two-Ply Air-Jet Spun Yarns

The work described in this study focuses on determining the influence of various parameters such as assembly and twisting nozzle pressures, yarn count, and material type on the properties of two-ply air-jet spun yarns produced using a spin-assembly-winder concept on the PLYfiL system. The results show that the tenacity, irregularity, and hairiness of both untwisted and twisted yarns are influenced by changes in the nozzle pressure. Lower pressures in this range generally result in better tenacity values for twisted yarns. It is also likely that the properties of fibers and sliver are factors that affect yarn quality in air-jet spinning.