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This study aimed at developing a geometrical model for predicting the sewing thread consumption of stitch class 406. Stitch class 400 is a multi-thread chain stitch which consumes a less amount of thread as compared with stitch class 500 but more thread as compared with stitch class 300. Sewing thread calculation plays a significant role in determining the exact amount of thread for completing a garment and predicting the right quantity of thread for bulk production. The geometrical model developed was used for predicting sewing thread consumption by using different factors like stitch density (8 and 12 SPI), material thickness (2, 4 and 6 layers of fabric), and type of material (denim, knitted and fleece). The model was validated with a total of 18 samples sewn with different kinds of fabric, SPI, and material thickness. It was concluded that the model could predict sewing thread consumption with more than 97.18% accuracy. [ABSTRACT FROM AUTHOR]

In the article, the change in the linear dimensions of tissues is analysed by the closure of the elastane threads in the tissue system under the influence of wet processing. It is found that standard techniques cover changes in linear dimensions only in the direction of the base and utka. However, for clothing design, it is necessary to know the change in linear dimensions in arbitrary directions. The empirical models used to calculate these dimensions do not have the required accuracy. The article proposes a model for calculating the change in linear dimensions in an arbitrary direction based on the analysis of the geometry of the fabric and describing the process of tissue shrinkage under the influence of wet processing, which allows to obtain results with sufficient accuracy. [ABSTRACT FROM AUTHOR]

This paper suggests a technique for the construction of fabric three-dimensional models based on the piecewise continuous representation of the thread surface. The approach allows to exclude such simulation defects as "interpenetration" of threads in the fabric, and takes into account the geometric features of the thread structure, the possibility of their bending in several planes, and changes in the form and sectional area. The geometric models obtained can be used to analyse the forces and deformations occurring in the fabric with the help of the finite-element simulation programs in various specialised software complexes, such as ANSYS, LS-DYNA, ABAQUS, NASTRAN etc. The structure parameters which are difficult to calculate using standard techniques, e.g. the pore volume and contact area between threads can be calculated with the help of describing the fabric three-dimensional structure. [ABSTRACT FROM AUTHOR]

This paper deals with the prediction of the sewing thread consumption of jean trousers using the neural network technique. The neural network results and analysis are discussed and investigated. Indeed the findings show that neural network consumption values give better fitting of experimental results than the ones obtained using regression technique. However, compared to the experimental consumption results, theoretical ones of the sewn jean pants seem widely predictable in the desired field of interest. Among the all parameters studied, statistical analysis results also indicate that five inputs can be considered as influential ones. When classifying these five influential inputs, only three parameters are considered most significant. In fact the thread consumed to sew jean trouser samples remains influenced especially by the thread properties and needle fineness as well. Compared with the regression model, the neural network model gives a more accurate prediction and to a great extent provides the amount of sewing thread. [ABSTRACT FROM AUTHOR]

To replace time-consuming and lab-intensive of manual inspection, a Fourier transform is proposed to detect the thread densities of woven fabric in this paper. First, theories of the Fourier transform, yarn image reconstruction and the threshold method are introduced. Then the steps of fabric image acquisition, the Fourier transform of the fabric image, feature analysis in the frequency domain, image construction of fabric yarns, and threshold processing are analysed. Lastly, after locating and counting the yarns in the fabric segmentation results, thread densities of the woven fabric are calculated. The experimental results prove that the method proposed can detect the thread densities of woven fabric correctly and it can be used to replace the current manual analysis. [ABSTRACT FROM AUTHOR]

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Research on the flow field in the fibre-converging zone is always the emphasis and difficulty of compact spinning. Therefore in this work numerical studies on the three-dimensional flow field in four-roller compact spinning with a guiding device were carried out using Fluent software. First a three-dimensional physical model of the fibre-converging zone was obtained using AutoCAD software. Then numerical simulations of the three-dimensional flow field in four-roller compact spinning with and without a guiding device were presented, respectively, using Fluent software. It was shown that the negative pressure is chiefly concentrated near the air-suction flume, and the velocity reaches the maximum on the centre line. Comparing with the flow field in compact spinning without a guiding device, the effective range of negative pressure in four-roller compact spinning with a guiding device increases significantly and negative pressure use efficiency improves accordingly. Furthermore the optimal installation position of the guiding device was studied, and it was shown that the optimal installation position is closely related to the linear density of the spun yarn. Finally the theoretical results obtained were illustrated by experiments. [ABSTRACT FROM AUTHOR]

One of the most important mechanisms used in sewing machines is the needle bar and takeup lever mechanism. Being almost the same in nearly all classical sewing machines, this mechanism enables sewing by allowing movement of the needle and pulling of the thread for stitch formation. This study deals with the design of a new modified thread take-up lever mechanism which can be used as an alternative to the classical mechanism. The dimensional design of the mechanism was made by taking into consideration the limitations of sewing mechanics. [ABSTRACT FROM AUTHOR]

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Both physical and mathematical models of lockstitch tightening are determined. The basic dynamical equation is a second-order differential correlation with respect to time; the forces applied are analysed and defined. The supplemented correlations are formulated by means of basic physical phenomena. The total angle of contact on the mobile barriers of the disc is introduced by physical analysis of the take-up mechanism. Both mechanical and thermal elongation are determined within the thread and introduced into the basic dynamical equation. The set of equations can be solved by means of any processing software (for example Mathematica) and the results obtained visualised for different parameters. [ABSTRACT FROM AUTHOR]

In this paper, flow patterns, such as the velocity distribution along the radius of the nozzle block at section A-A and static pressure distributions along the nozzle block axis and its radius at section A-A, affected by the nozzle block's structure parameters and the velocity at the jet orifice exit in Murata vortex spinning are investigated by the method of numerical computation. The results show that the tangential, axial and radial velocities inside the nozzle block are significantly affected by the jet orifice angle and velocity at the exit of the jet orifice as well as by the diameter at the inlet of the nozzle block. Static pressure distributions inside the nozzle block are significantly affected by the jet orifice angle, the velocity at the exit of the jet orifice, the outer diameter of the hollow spindle and the distance from the inlet of the nozzle block to the inlet of the hollow spindle. [ABSTRACT FROM AUTHOR]

This paper deals with the surface properties of dyed cotton fibres, which were analysed by measuring the streaming potential. Diversified values of the potential were obtained for samples of fabrics dyed with model direct dyes 1-10. Changes in the streaming potential in water solutions of the model dyes were also analysed in order to determine the impact of polar functional groups of the dyes on their anion character. For a broader view of the phenomenon discussed, the analysis of the surface properties of fibres was supplemented with a description of the relative dye content in the fibre, using the K/S ratio. Streaming Potential -- Characteristics of Dyed Cotton Fibres. [ABSTRACT FROM AUTHOR]

In this study, polyester staple fiber core/polyester sheath and polyester staple fiber core/ viscose sheath DREF-3 core yarns were produced using different spinning parameters in order to understand their effect on yarn tensile properties. Yarns of 65 tex linear density were produced using three different core/sheath ratio levels x four different spinning drum speeds x three different air suction pressures at a constant opening roller speed of 4200 r.p.m and constant production speed of 100 m/min. The tensile properties of the yarns were tested, and the results obtained were evaluated by regression analysis using an SPSS statistical program at a 0.05 significance level. The effect of the core/sheath ratio on yarn tenacity and yarn elongation at break properties are significant. With an increase in the core/sheath ratio, yarn tenacity decreases due to insufficient wrapper fibers in the yarn. An increase in the core ratio decreases yarn elongation because sheath fibers are in a buckling form, helically wound in the yarn structure, in which there is more chance for yarn extension. An increase in the spinning drum speed damages fiber in the sheath and increases the number of hooks at the end of fibers, as a result of which the core yarn tenacity decreases. However, an increase in the spinning drum speed does not have a significant effect on the yarn elongation at elongation at breakratio. At a higher air suction pressure, Polyester/viscose yarn tenacity and the elongation at break ratio increase. On the other hand, the air suction pressure does not have a significant effect on the tensile properties of polyester/polyester yarns. It appears that the effect of air suction pressure changes according to the physical properties of fiber in the sheath. The air suction pressure may only have a significant effect on yarn tensile properties when short and coarse fibers are used in the sheath. [ABSTRACT FROM AUTHOR]

The purpose of the research presented was to analyse the influence of the fabric surface cover factor and fabric colour values on the degree of UV ray transmittance and the UV protective factor (UPF). The research was carried out on lightweight coloured fabrics woven in sateen weave with different densities of warp and weft threads and with different colours in the weft. Measurements of the UPF were performed using the "in vitro" method in the range of UVA and UVB ray wavelengths, from 280 to 400 nm. The results of the research confirm the importance of the fabric surface openness for the UV protective factor and expose the influence of the fabric face and reverse sides as well as of colour values L*, C*ab, hab of warp and weft threads on the UPF in sufficiently closed woven constructions. Namely, constructions with less than the 5% surface openness offer excellent protection (UPF above 50), whereas constructions with less than 10% surface openness offer good to very good protection (a UPF above 20). At coverage higher than 95%, the fabrics analysed could be generally divided into three groups with respect to the effectiveness of their UV protection:fabrics of darker colours (black, blue) with extremely high UPF values,fabrics of chromatic lighter colours (yellow, red, green) with UPF values half of those of darker colours in general, and white fabrics (bleached) in which the desired UPF values are not reached regardless of the degree of the cover factor. [ABSTRACT FROM AUTHOR]

The aim of this work was to study a new way of modelling the behaviour of structures of woven fabrics after mechanical loading. As the basis of our considerations, on the beginning of this working, a classical Painter nomogram was introduced. The modelling was done through the realisation of the following scientific - research aims: analysis of the behaviour of the structures of woven fabrics subjected to different static loads, study of methods of expectation of mechanical property at designing of fabrics, study of techniques enabling the analysis of the structure of fabrics subjected to deforming strengths, and a analysis of the property of fabrics with respect to the basic parameters of fibres and yarns. The devising of new, modified Painter nomograms made it possible to model the change in structure of fabric subjected to a static load, thanks to which it is possible to reflect the structure of internal real fabrics recreated, eliminating the generalisation of the Painter nomogram. [ABSTRACT FROM AUTHOR]

The purpose of the research presented was to analyse the influence of the fabric surface cover factor and fabric colour values on the degree of UV ray transmittance and the UV protective factor (UPF). The research was carried out on lightweight coloured fabrics woven in sateen weave with different densities of warp and weft threads and with different colours in the weft. Measurements of the UPF were performed using the "in vitro" method in the range of UVA and UVB ray wavelengths, from 280 to 400 nm. The results of the research confirm the importance of the fabric surface openness for the UV protective factor and expose the influence of the fabric face and reverse sides as well as of colour values L*, C*ab, hab of warp and weft threads on the UPF in sufficiently closed woven constructions. Namely, constructions with less than the 5% surface openness offer excellent protection (UPF above 50), whereas constructions with less than 10% surface openness offer good to very good protection (a UPF above 20). At coverage higher than 95%, the fabrics analysed could be generally divided into three groups with respect to the effectiveness of their UV protection: fabrics of darker colours (black, blue) with extremely high UPF values,fabrics of chromatic lighter colours (yellow, red, green) with UPF values half of those of darker colours in general, and white fabrics (bleached) in which the desired UPF values are not reached regardless of the degree of the cover factor. [ABSTRACT FROM AUTHOR]

Textile technologies are characterised by zones in which threads are stretched between elements of different machines and working elements of the same machine on which the drawn threads are displaced. The length of these zones is from several millimetres to several metres. The variability of tensions in the displaced threads is caused by technological conditions and the factors connected with the non-uniformity of the mechanical properties of threads. The mathematical modelling of forces presented in literature does not often consider the mechanical non-uniformity of the raw material and therefore only presents average values of the force without informing about the parameters of the value dispersion which is observed in real processes. The aim of this article is to attempt to evaluate the influence of the non-uniformities of the mechanical properties of yarns on the generation of forces acting in threads pulled through friction barriers and on their character. Broad ranges of thread speed values and the curvature radii of the barriers were accepted in our computer simulations. The model described in this article is a development of solutions described earlier. [ABSTRACT FROM AUTHOR]

The selection of sewing needles, the fineness of sewing thread, relative air humidity, as well as the thickness and density of knitted fabric play a significant role in the technological process of sewing. Damage to knitted fabric loops during sewing are closely connected with sewing needle penetration force and dynamic tension values of the sewing thread. In this research an instrument for measuring the sewing needle penetration force and dynamic sewing thread tension force was designed. [ABSTRACT FROM AUTHOR]

In this paper the methodology of studies on the impact air-permeability of fabrics is presented. Stands for the static and dynamic investigation of textiles are described. A mathematical model of the pressure drop in a fabric resulting from the impact of airflow through the product has also been submitted. A measure of impact permeability in the form of an index for arranging fabrics with respect to their flow properties is given. Characteristic features of the structure of a woven fabric from a group of products of negative, positive and small index are shown. [ABSTRACT FROM AUTHOR]

A simulation was carried out of forces acting in a thread of random variable visco-elastic rheological properties, which is displaced through a model drawing zone. This zone consists of two pairs of rollers working at different tangential velocities. The computer simulations carried out indicated a significant influence of irregularities in the thread's visco-elastic properties on the stochastic character of the thread tensions. The latter decrease with an increase in the length of the drawing zone, and rise with the velocity of thread displacement. The model described in this article is a development of the model based only on the elasticity theory elaborated previously by the autors, and also described in Fibres & Textiles in Eastern Europe. [ABSTRACT FROM AUTHOR]

During the formation of lockstitches in the sewing machine, the thread inserted into the stitch link by the needle undergoes extreme destruction as the result of the machine tool's action. The stage of inserting the interlacement into the needle channel (known as stitch tightening), connected with the thread take-up working programme, is presumed to be the most destructive stage for the thread. In this paper, the model of the stitch tightening process in dynamic conditions is presented. It allows us to assess the location of the interlacement in the stitch link, as a function of the sewing process technological parameters, such as the machine rotary speed, the restraint forces of the needle thread and the bobbin hook thread, the geometrical characteristics of the stitch formation zone, the thread elastic features etc. [ABSTRACT FROM AUTHOR]

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The model of the feeding process of anisotropic warp knitted fabrics includes a mathematical model of a knitted fabric in which the surface distribution of variable features oft he knitted fabric structure is defined in the form of numerical matrixes, the criteria of selecting the feeding method are defined on the basis of the existing technologies and the definition of forcing the feeding system on the basis of the kinematics of loop-forming elements, and finally the gradient of length of the fed and required threads in structural elements of the knitted fabric. Identifying the feeding system dynamics at constant-length thread feeding formulates the assumptions of the physical model. The mathematical model describes time courses of variations in dynamic forces in threads in a stitch repeat. On the basis of the algorithm of calculations, a numerical simulation of thread feeding was carried out for the structure of a jacquard knitted fabric, determining the extreme values of forces in the fed warp threads. [ABSTRACT FROM AUTHOR]

In this paper, the ability of the pulling-through method with a distance plate for measuring the shearing properties of knitted fabrics was studied. The conventional extraction method does not have a good correlation with the shearing properties of woven fabrics due to the complex deformation of the fabrics during testing. This study investigated a modified approach very similar to the conventional extraction method in order to evaluate the shearing behaviour of knitted fabrics. In this technique, the test is performed by a special pulling device mounted on a tensile testing machine consisting of two transparent horizontal plates: a replaceable base plate with a hole in the center, and a distance plate placed at a specified distance from the base plate. The shear properties of different knitted fabrics were measured by KES and the pulling-through method. The results reveal a high correlation between the pulling-through curve features and shear properties of the knitted fabrics. [ABSTRACT FROM AUTHOR]