scholarly journals The Effect of Single and Dual-Core Yarns Produced with Different Core Materials on the Elasticity and Recovery Properties of Denim Fabrics

2019 ◽  
Vol 2 (4) ◽  
pp. 174-182
Author(s):  
Tuba Bedez Ute ◽  
Huseyin Kadoglu

Elastic structures are preferred for improving the elasticity and recovery of the fabrics. Bagging, which is a three-dimensional fabric deformation, is an undesirable appearance of fabrics. The lack of dimensional stability or recovery after pressure on the fabrics causes bagging deformation. In recent years, denim manufacturers prefer double-core yarns to cope with the problem of bagging. In this study, various types of weft yarns were produced by using different core materials in different combinations. Double-core and single-core ring-spun yarns (Ne 18, ae 4,4) were used as weft yarns in weaving. Yarn and fabric samples were conditioned under standard atmospheric conditions and measured according to the related test standards. Yarns were tested and evaluated for important physical and mechanical properties such as evenness, imperfections, tenacity, breaking elongation, hairiness and yarn liveness. For denim fabric samples, all tests were performed after 3 consecutive domestic washing processes. Test results showed that there are significant differences between fabric properties depending on the weft yarn characteristics. By using double-core weft yarns in denim fabric production, consumers can have stretch jeans for improving body movement comfort while exhibiting low growth and shrinkage values.

2019 ◽  
Vol 2019 ◽  
pp. 125-131
Author(s):  
Münevver ERTEK AVCI ◽  
Esin SARIOĞLU ◽  
Gizem KARAKAN GÜNAYDIN

Denim fabrics which are highly demanded products among the world have high consumption rate in the textile market. Those fabrics may be utilized for different purposes. Durability, elasticity, wearing resistance are the important expected properties from denim fabrics. Tearing resistance of denim fabrics in use is another parameter that should be considered. This study includes the investigation of tearing properties of denim fabrics produced from single core (Polyethylene terephthalate/Polytrimethylene terephthalate (PET/PTT) bicomponent filament and elastane) and dual core (PET/PTT+elastane feeding simultaneously) spun yarns utilized as weft yarns. Denim fabrics with different layout of these weft yarns with uncovered PET/PTT bicomponent filament were produced in order to compare the tearing strength properties in warp and weft wise. Results revealed that highest tearing strength of weft wise was obtained from denim fabrics at 2F:2CY layout where two uncovered PET/PTT bicomponent filament and two PET/PTT bicomponent filament+elastane dual core-spun yarn were used consecutively in the layouts. The lowest tearing strength was found among the denim fabrics at 1F:6CY layout where one uncovered PET/PTT bicomponent filament and six PET/PTT bicomponent filament+elastane dual core-spun yarns were used consecutively in the layouts. According to statistical evaluation; Weft yarn type, weft yarn layout and their interaction in the fabric were found to having significant effects on tearing strength for both warp and weft direction of denim fabric at significance level of 0.05.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4284
Author(s):  
Lvtao Zhu ◽  
Mahfuz Bin Rahman ◽  
Zhenxing Wang

Three-dimensional integrated woven spacer sandwich composites have been widely used as industrial textiles for many applications due to their superior physical and mechanical properties. In this research, 3D integrated woven spacer sandwich composites of five different specifications were produced, and the mechanical properties and performance were investigated under different load conditions. XR-CT (X-ray computed tomography) images were employed to visualize the microstructural details and analyze the fracture morphologies of fractured specimens under different load conditions. In addition, the effects of warp and weft direction, face sheet thickness, and core pile height on the mechanical properties and performance of the composite materials were analyzed. This investigation can provide significant guidance to help determine the structure of composite materials and design new products according to the required mechanical properties.


2001 ◽  
Author(s):  
Florin Ilinca ◽  
Jean-François Hétu

Abstract This paper presents simulations of co-injection molding problems computed by a three-dimensional finite element method. The polymer melts behave as generalized Newtonian fluids and non-isothermal effects are taken into account. In addition to the momentum, mass and energy equations, we solve two transport equations tracking the polymer/air and skin/core polymers interfaces. Solutions are shown for a center gated rectangular plate. The effect of varying the melt/mold temperature and the ratio between the skin and core materials is investigated. The solution obtained for the same skin and core materials is compared with those in which viscosities of core and skin materials are different. Finally, the solution for the co-injection of a C-shaped plate is presented.


Author(s):  
Mirjamol Mirkarimovich Mirkhojaev ◽  

For the study, samples of 2 variants of suiting fabrics were selected: a twill weave fabric with a woolen fiber base and a polyester fiber weft yarn, as well as a 100% woolen fiber fabric and physical and mechanical properties were determined using modern equipment.


Author(s):  
Inna Slepchuk ◽  
Olga Ya. Semeshko ◽  
Yuliya G. Saribekova ◽  
Irina N. Kulish ◽  
Igor V. Gorokhov

Results of study of influence of amount of functional groups of glycidyl ethers on characteristics of the spatial grid of crosslinked polyurethane polymer are presented. Parameters of a three-dimensional spatial grid of investigated samples of polymeric films and their physical and mechanical properties were determined by a method of equilibrium swelling in organic solvents.


2015 ◽  
Vol 15 (3) ◽  
pp. 191-197 ◽  
Author(s):  
Xiaoying Li ◽  
Gaoming Jiang ◽  
Xiaolin Nie ◽  
Pibo Ma ◽  
Zhe Gao

AbstractThis paper introduces a knitting technique for making innovative curved three-dimensional (3D) spacer fabrics by the computer flat-knitting machine. During manufacturing, a number of reinforcement yarns made of aramid fibres are inserted into 3D spacer fabrics along the weft direction to enhance the fabric tensile properties. Curved, flat-knitted 3D spacer fabrics with different angles (in the warp direction) were also developed. Tensile tests were carried out in the weft and warp directions for the two spacer fabrics (with and without reinforcement yarns), and their stress–strain curves were compared. The results showed that the reinforcement yarns can reduce the fabric deformation and improve tensile stress and dimensional stability of 3D spacer fabrics. This research can help the further study of 3D spacer fabric when applied to composites.


2014 ◽  
Vol 42 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Matteo Zago ◽  
Andrea Francesco Motta ◽  
Andrea Mapelli ◽  
Isabella Annoni ◽  
Christel Galvani ◽  
...  

Abstract Soccer kicking kinematics has received wide interest in literature. However, while the instep-kick has been broadly studied, only few researchers investigated the inside-of-the-foot kick, which is one of the most frequently performed techniques during games. In particular, little knowledge is available about differences in kinematics when kicking with the preferred and non-preferred leg. A motion analysis system recorded the three-dimensional coordinates of reflective markers placed upon the body of nine amateur soccer players (23.0 ± 2.1 years, BMI 22.2 ± 2.6 kg/m2), who performed 30 pass-kicks each, 15 with the preferred and 15 with the non-preferred leg. We investigated skill kinematics while maintaining a perspective on the complete picture of movement, looking for laterality related differences. The main focus was laid on: anatomical angles, contribution of upper limbs in kick biomechanics, kinematics of the body Center of Mass (CoM), which describes the whole body movement and is related to balance and stability. When kicking with the preferred leg, CoM displacement during the ground-support phase was 13% higher (p<0.001), normalized CoM height was 1.3% lower (p<0.001) and CoM velocity 10% higher (p<0.01); foot and shank velocities were about 5% higher (p<0.01); arms were more abducted (p<0.01); shoulders were rotated more towards the target (p<0.01, 6° mean orientation difference). We concluded that differences in motor control between preferred and non-preferred leg kicks exist, particularly in the movement velocity and upper body kinematics. Coaches can use these results to provide effective instructions to players in the learning process, moving their focus on kicking speed and upper body behavior


2019 ◽  
Vol 14 ◽  
pp. 155892501988996
Author(s):  
Zhenyu Ma ◽  
Pingze Zhang ◽  
Jianxun Zhu

Three-dimensional textile fabrics are used as the reinforcing phase of the textile structural composites, and their geometry affect the physical and mechanical properties of composites. Based on the curvature and directions of the fiber tows in three-dimensional textile fabrics, four representative geometric units are proposed, namely, the orthogonal geometric unit, the curved geometric unit, the skew geometric unit, and the uniform distribution unit, respectively. Other units are the combinations or derivations of these representative geometric units. The relationship and performance characteristics of these representative geometric units are discussed in section “The relationship of RGUs.” The structural features of three-dimensional textile fabrics are illustrated on the mesoscopic scale, and the models are established to predict the geometric properties. The concepts of fabrics with stable structure, flexible structure, elastoplastic structure, and uniform structure are proposed. The fiber volume fractions and elastic characteristics of different structural fabrics are discussed. The classification of three-dimensional textile fabrics is conducive to investigate the relationship between geometry and property, forming a technical system and providing a theoretical basis for the selection of three-dimensional structural textile composites with different performance.


2019 ◽  
Vol 13 (7) ◽  
pp. 1911-1923 ◽  
Author(s):  
Ilaria Tabone ◽  
Alexander Robinson ◽  
Jorge Alvarez-Solas ◽  
Marisa Montoya

Abstract. The Northeast Greenland Ice Stream (NEGIS) has been suffering a significant ice mass loss during the last decades. This is partly due to increasing oceanic temperatures in the subpolar North Atlantic, which enhance submarine basal melting and mass discharge. This demonstrates the high sensitivity of this region to oceanic changes. In addition, a recent study suggested that the NEGIS grounding line was 20–40 km behind its present-day location for 15 ka during Marine Isotope Stage (MIS) 3. This is in contrast with Greenland temperature records indicating cold atmospheric conditions at that time, expected to favour ice-sheet expansion. To explain this anomalous retreat a combination of atmospheric and external forcings has been invoked. Yet, as the ocean is found to be a primary driver of the ongoing retreat of the NEGIS glaciers, the effect of past oceanic changes in their paleo evolution cannot be ruled out and should be explored in detail. Here we investigate the sensitivity of the NEGIS to the oceanic forcing during the last glacial period using a three-dimensional hybrid ice-sheet–shelf model. We find that a sufficiently high oceanic forcing could account for a NEGIS ice-margin retreat of several tens of kilometres, potentially explaining the recently proposed NEGIS grounding-line retreat during Marine Isotope Stage 3.


2009 ◽  
Vol 9 (13) ◽  
pp. 4467-4483 ◽  
Author(s):  
M. T. Prtenjak ◽  
A. Jeričević ◽  
L. Kraljević ◽  
I. H. Bulić ◽  
T. Nitis ◽  
...  

Abstract. Stable atmospheric conditions are often connected with the occurrence of high pollution episodes especially in urban or industrial areas. In this work we investigate a severe SO2 episode observed on 3–5 February 2002 in a coastal industrial town of Rijeka, Croatia, where very high daily mean concentrations (up to 353.5 μg m−3) were measured. The episode occurred under high air pressure conditions, which were accompanied with a fog and low wind speeds. Three air quality models (50-km EMEP model, 10-km EMEP4HR model and 1-km CAMx model) were used to simulate SO2 concentrations fields and to evaluate the relative contribution of distant and local pollution sources to observed concentrations. Results suggest that the episode was caused predominately by local sources. Furthermore, using three-dimensional, higher-order turbulence closure mesoscale meteorological model (WRF), the wind regimes and thermo-dynamical structure of the lower troposphere above the greater Rijeka area (GRA) were examined in detail. Modelled atmospheric fields suggest several factors whose simultaneous acting was responsible for elevated SO2 concentrations. Established small scale wind directions supported the transport of air from nearby industrial areas with major pollution sources towards Rijeka. This transport was associated with strong, ground-based temperature inversion and correspondingly, very low mixing layer (at most up to about 140 m). Additionally, the surface winds in Rijeka were light or almost calm thus, preventing ventilation of polluted air. Finally, a vertical circulation cell formed between the mainland and a nearby island, supported the air subsidence and the increase of static stability.


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