On the contribution of yarn–yarn slippage to woven fabric failure

Failure of woven fabrics involves an interaction between yarns, which can be predicted by yarn slippage. To investigate the contribution of yarn slippage to the failure, we analyzed the relation between various failure properties and critical slippage force (F_S) using plain and twill weaves of fabrics with different characteristics. Results show that F_S increases with yarn density and yarn linear density. The properties in tension for fabrics with different weaves, yarn density, and yarn linear density superimpose on master curves described by a linear relationship when expressed as a function of F_S. The same linear behavior is observed when the critical jamming force of yarns expressed as a function of F_S. For the tearing energy, a master curve is also obtained when expressed as a function of F_S; however, the curve has a polynomial shape. F_S thus appears as a valuable tool to predict the onset of damage in fabrics.     

Length of the yarn in plain‐weave crimp wave

Yarn axis geometry in plain‐weave fabrics has been described by different models. Yet, they do not capture its exact shape, because (1) the geometry of each crimp wave in a fabric is unique to that fabric and as such it differs from any generalized model, and (2) the length of the yarn axis, an important parameter, is more influenced by the height of the crimp wave than by any arbitrary definition of its shape. Crimp of the warp/weft is defined as the ratio of the length of the yarn axis in one wave and its wave length; the latter is the spacing (pitch) of the neighboring weft/warp yarns. Crimp can be calculated in accordance with the crimp wave shape definition, which differs from reality. In this paper, a new and very simple method of calculating the yarn crimp is proposed and validated through experimental measurements. The results provide an instrument for easy calculation of yarn lengths when crimp wave amplitudes and wavelengths are known.     

Finite element simulation of three‐dimensional angle‐interlock woven fabric undergoing ballistic impact

This paper presents finite element simulations of three‐dimensional (3D) angle‐interlock woven fabric (3DAWF) undergoing ballistic impact. A micro‐structure model of the 3DAWF was established at the fiber tow level. Incorporated with commercial finite element code, ABAQUS/Explicit, the ballistic impact damage of the 3DAWF was simulated and compared with that in the experiment. Residual velocities of the conically cylindrical steel projectile (Type 56 in Chinese Military Standard) with different strike velocities were calculated and verified with those in the experiment. There are good agreements of the impact damage of the 3DAWF and the residual velocities of the projectile between finite element results and experimental results. The acceleration fluctuation record of the projectile and the stress wave propagation in the 3DAWF obtained from the simulation reveal the impact damage mechanisms of the 3DAWF. The strain rate effect of the fiber tows on the ballistic performance are also discussed. Such a micro‐structure model could be extended to the design of the impact behavior of the 3DAWF composites.     

Analytical studies on woven fabrics’ bagging performance affected by the material,yarn, and fabric parameters

The present work focuses on investigating the bagging behavior of woven fabrics produced from viscose and polyester/viscose yarns. In this paper, the bagging deformation – in terms of different bagging parameters (bagging resistance, bagging fatigue, bagging hysteresis, and residual bagging hysteresis) – has been interpreted by fabric’s physical and mechanical properties which were obtained from FAST system. The statistical analysis revealed that there is a significant correlation between the bagging parameters. Also, it was concluded that the samples’ physical and mechanical properties correlate significantly with bagging parameters. Additionally, the effects of four different variables such as material type, spinning system, weave pattern, and weft density on bagging parameters have been studied. Considering the high correlations between all the bagging parameters, it was decided to analyze only the parameter bagging fatigue in this paper. The results showed that all the fabric variables except the parameter weft density have significant effects on bagging fatigue performance.     

Draping the two pieces of pencil pants by woven fabric北大核心

This paper attempts to combine side seam of pants by draping and blocking, produce no lateral seam and fitted pants. The pencil pants although produced by bombs or less elastic woven cloth, but can still do a snug fit, as a result of the merger the outside seam. The whole pair of trousers is composed of only two main cut pieces, which maximum retention fabric patterns and integrity and avoid machining process on the articles, of lattice, the flowers produce fabric loss and reduce processing cost, in the visual produced special beauty of technology. The study adds a new category for woven fabric pants.     

Energy absorption of 3D orthogonal woven fabric under ballistic penetration of hemispherical‐cylindrical projectile

The non‐crimp features of warp and weft yarns impart the highest energy absorptions to 3D orthogonal woven fabric (3DOWF) than other kinds of 3D woven fabrics under ballistic impact. There are greater potential applications of the 3DOWF in ballistic protection. In this paper, an analytical model was proposed to calculate the energy absorption of the 3DOWF under ballistic penetration of a hemispherical‐cylindrical rigid projectile. The analytical model covers the calculations of the energies absorbed by the warp, weft, and Z‐yarns and the determinations of penetration time from the impact loading strain rate. The stress wave propagations in the warp, weft, and Z‐yarns were analyzed to formulate the fabric deformation and strain energy. The influence of strain rate on the residual velocities of the projectile was investigated. From the absorbed energy distribution calculated by the analytical model, the factors for improving ballistic performance of the 3DOWF are discussed.     

Two‐way prediction of cotton yarn properties and fiber properties using multivariate multiple regression

This paper explains the feasibility of two‐way prediction by developing direct models relating fiber to yarn and reverse models relating yarn to fiber using multivariate methods simultaneously. These models evaluate the dependencies of cotton yarn properties on fiber properties and vice versa with minimum random errors and maximum accuracy. To this end, cotton fiber properties were measured from rovings carefully untwisted. An HVI system and an evenness tester of premier were used to measure the various properties. The samples of cotton yarns (108 samples) produced yarn counts ranging from 16 to 32 Ne with optimum twist factor. In this study, effective variables were selected by multivariate statistical test (m‐test). Then, multivariate analysis of variance (MANOVA) was used for evaluating the significance of obtained models. Next, the optimal separate equations were determined through multivariate multiple regression. After solving the linear equation system, a reverse model was achieved. By selecting fiber properties and machine factors as appropriate variables, the relative importance of these factors was also investigated. The results showed that the obtained equations were significant at the significance level α = 0.01.     

Electrical conduction investigation of stainless steel wire‐reinforced cotton fabric composites by electrospraying of fluoropolymer

This study investigates the effect of the incorporation of stainless steel (SS) wires into cotton fabrics on the conductivity of the fabric in order to ease the electrospraying of an emulsified fluoropolymer resin. The statistical analysis showed that the increase in the conductivity of the fabric surface significantly lowered the deposition time of the fluoropolymer resin onto the fabric surface; however, the electrical voltage applied during electrospraying and the flow rate of the emulsion in the electric field had a greater effect on the deposition time of the process than the conductivity of the fabric.     

Investigating the effect of weight reduction treatment on Poisson’s ratio of microfiber polyester woven fabric

Polyester is one of the important fibers among man-made fibers. One of the finishing processes for improving the performance of polyester fabrics is weight reduction treatment. This treatment has a considerable effect on the mechanical properties of such fabrics. In this research, the effect of weight reduction treatment on changes in the Poisson’s ratio of a microfiber polyester woven fabric treated with four different sodium hydroxide concentrations was studied. Poisson’s ratio of the fabric at 10 levels of extension was measured. Results show that from 1% to about 5%, the Poisson’s ratio increases non-linearly. After this point up to 10%, the Poisson ratio decreases by a linear trend. There is a significant variation in the results at lower extensions, and by increase in extension, this variation reduces. Statistical analysis showed that weight reduction at percentages lower than 25% does not affect the Poisson’s ratio of the fabric. In the range of 6–10%, there is a high non-linear correlation between the weft crimp and Poisson’s ratio. In addition, there is a high non-linear correlation between Poisson’s ratio and fabric cover factor.     

Properties research of doubling and twisting yarn fabric of wool/bamboo charcoal filament北大核心

The experimental material uses doubling and twisting yarn worsted fabric of wool and bamboo charcoal filament attached to new green environmental fiber. It selects tensile property, antiwrinkle performance, moisture permeability and UV protection performance in particular. The result is all new products have better tensile property and moisture permeability compared with wool and bamboo charcoal filament interlacing fabric. Moisture permeability of doubling and twisting yarn fabric increases and UV protection performance falls off gradually when weight and weave is equation of all fabric. It also gets No. 1 sample has optimal performance in four properties when the content of bamboo charcoal filament is 29.5% ,the twist is 58.5 twist/10 cm, the weave is plain, the square meter gram weight is 144 g/m2 by product performance rank method.     

Effect of relative rubbing speed on the tribo‐electrification of continuous filament yarn by stainless steel pins

The effect of relative rubbing speed on the tribo‐electrification between different continuous filament yarns and stainless steel “charging pins” was analysed. A modified linear tester, housed in an environmental room, was used to charge the yarn while transporting at desired speed and input tension. The yarn was rubbed against the charging pin, which was also rotated at different speeds. The yarn surface charge, yarn output tension and charging pin’s vibration were monitored in real time automatically. The results showed that for nylon yarn charge was minimized when the yarn/pin relative speed approached zero, regardless of the absolute rubbing speeds of yarn and pin. It was also found that, at the same relative speed, less charge was generated when a larger pin was used. For finish‐free nylon yarn, the charge was also minimized as the relative speed approaches zero; however, for finish‐free polyester yarn and finish‐free polypropylene yarn, the effect of relative rubbing speed on the electrification was not very significant.     

Geometrical analysis of co‐woven knitted preform for composite reinforcement

In this paper, a co‐woven knitted (CWK) structure for composite reinforcement is presented. Based on the experimental observations, its unit cell and representative volume element (RVE) geometries were identified along with the idealized cross‐sectional shapes of the weft, warp and stitch yarns. A geometrical model for the RVE was proposed and the mathematical equations were derived to describe the relationships between the geometrical parameters and process variables. The model was verified with the experimental data and good agreements were obtained between the calculations and measurements of different yarn lengths in a RVE. The inserted and stitch fiber volume fractions as well as total fiber volume fraction were calculated and their variations with the stitch‐to‐inserted yarn linear density ratio under different fabric tightness factors were discussed. The geometrical model provides a basis for the establishment of process windows for the CWK preforms as well as for the prediction of the mechanical behavior of the CWK‐reinforced composites.     

Clothing woven with titanium dioxide-infused yarn: potential to increase exercise capacity in a hot,humid environment?

Exercise and physical labor in hot, humid environments carries the risk of heat-related injury and reduced exercise capacity. The purpose of this study was to evaluate the effect of wearing a shirt woven from a titanium dioxide (TiO2)-infused yarn on the physiological response to exercise in a hot, humid environment. Volunteers (N = 14) were recruited to participate in two exercise trials (45 min of interval treadmill exercise at 35 °C, 55% RH): control (Nylon 66) and a TiO2-shirt (Nylon 66 with 3% TiO2). Rating of perceived exertion (RPE), perceived thermal comfort (TC), and exercise capacity at specific physiological strain index (PSI) cut-points (5.0, 7.5, and 9.0) were measured. Significantly lower RPE/TC and improved exercise capacity at PSI 7.5 and 9.0 were observed when wearing TiO2 (p < 0.05). On a preliminary basis, these results demonstrate, the potential of TiO2-infused clothing to improve perceptions of exertion/environment and exercise capacity.     

Identification of the broken-hole on the woollen fabric北大核心

This study is designed to identify the damage of the broken-holes on woollen fabric. We can use optical microscope, SEM and chemical method to identify the cause of the broken-hole. Under the optical microscope, if the damaged fibers appear a lunate gap or prominence on the cross section, it can belong to moth damage, if there are broken filaments on the cross section of damaged fibers, it can be regarded as mechanical damage, if the fibers stick together,it can be attributed to heat damage. Under the SEM, if the cross section is smooth, it is mechanical damage, otherwise it is moth damage. Under the treatment of saturated bromine, the moth damaged fiber bubbles at 92 seconds, while the mechanical damaged fiber bubbles at 37 seconds.     

A novel approach to the Poisson’s ratio of the yarn

Abstract

The Poisson’s ratio is a fundamental and inherent property of the materials in their reaction to loading. Determining the correct value of the Poisson’s ratio leads to more accurate predictions of the mechanical behavior of the material, especially in employing mechanical or numerical finite element modeling methods. In this study, seven different types of medium and coarse yarn were digitally filmed in seven sections from three various angles while tensile strength testing. Then, longitudinal and transverse strains and consequently, momentary deformation index and Poisson’s ratio of the yarns were calculated. Significance level of the mean Poisson’ ratio was also determined at different angles and sections using statistical comparison test. The results showed that the transverse strain has a convergent state at the end of the test and the start of the yarn breaking occurs at the convergence point. Additionally, in upper sections of yarn near to the movable jaw of the strength tester, the amount of the longitudinal strain increases which leads to reduce in momentary deformation index and Poisson’s ratio of the yarn. Moreover, a sectional mode to measure the Poisson's ratio was presented.     

A new approach to de‐curling force of single jersey weft‐knitted fabric

In this work, the curling behavior of cotton single jersey weft‐knitted fabric was studied using a new non‐destructive test method. Eighteen series of dry‐relaxed weft‐knitted fabric samples were produced with three different yarn twist levels (724.5 tpm, 807 tpm, and 890 tpm), two yarn twist directions (Z and S), and three different loop lengths (2.7 mm, 2.85 mm, and 3.2 mm). Curling behavior was characterized in terms of curling distance (CD), de‐curling force, and de‐curling energy. The results show that weft‐knitted fabric samples with a lower loop length and higher yarn twist level exhibited higher de‐curling force and de‐curling energy. It is indicated that the de‐curling force of weft‐knitted fabric samples produced from the Z‐twist cotton ring‐spun yarn is higher than that of the samples produced from the S‐twist cotton ring‐spun yarn. The regression analysis results also illustrate that de‐curling force and de‐curling energy are non‐linearly correlated with edge CD, and variation trends follow polynomial equations. The result of this research suggests that the curling behavior of weft‐knitted fabric can be predicted in terms of de‐curling properties.     

Influence and comparison of emerging techniques of yarn manufacturing on physical–mechanical properties of polyester-/cotton-blended yarns and their woven fabrics

Abstract

In this study, the physical–mechanical properties of ring spun, ring compact, rotor and air-vortex yarns were investigated. The study was carried with yarn having linear densities of 24.4 tex and 36.7 tex, which were then converted to woven fabrics. The ring spun yarns have higher values of strength but also with higher strength irregularities. Extra-ordinarily low hairiness was observed in air-vortex yarns due to its unique yarn formation technique. The deviation rate (DR) of yarns have correlation with the mass spectrogram of respective yarns obtained from USTER Tester 5. Rotor and air-vortex yarns exhibited higher coefficient of friction. The woven fabrics made from ring spun yarns exhibited higher tensile and tear strength with higher elongation at break. The fabrics made from air-vortex yarns have very good pilling grade due to less protruding fibres on their surface and good structural integrity.     

Use of low‐level plasma for enhancing the shrink resistance of wool fabric treated with a silicone polymer

This study examines the effects of an atmospheric pressure plasma (APP) pre‐treatment on the shrink resistance of wool fabric treated subsequently, by the pad/dry method, with an aqueous emulsion of the amino‐functional polydimethylsiloxane, SM 8709. Optimal shrink resistance (with no impairment of fabric handle) was obtained after a low‐level plasma treatment (1–3 s exposure time), using 5% of the polymer emulsion. Higher levels of silicone polymer could be used to achieve shrink resistance in the absence of a plasma pre‐treatment, but the fabric handle would be adversely affected. X‐ray photoelectron spectroscopy (XPS) studies showed that the bulk of the covalently bound surface lipid layer was removed after a plasma exposure time of 30 s. For treatment times of 3 s or less, however, the removal was incomplete, suggesting that optimum shrink resistance (after treatment with the silicone polymer) was associated with the modification of the surface layer rather than its complete destruction. Scanning electron micrographs (SEMs) revealed that the plasma pre‐treatment did not lead to any physical modifications (such as smoothening of the scale edges), even for long exposure times, and had no significant impact on the extent or nature of the inter‐fibre bonding of the polymer. Confocal microscopy showed uniform spread of polymer on single fibres. It is concluded that the main impact of the plasma pre‐treatment was to enhance the distribution of polymer both on and between fibres and to improve adhesion of polymer to the fibre.     

Reaction kinetics study of α-amylase in the hydrolysis of starch size on cotton fabrics

A study of tension surging and of the properties of the resultant yarns is reported. Tension profiles are discussed and assigned to three modes of operation, namely, pre-surging, surging, and post-surging. The critical conditions for these three modes and the wavelengths and amplitude of tension surging are investigated. The insertion of twist is examined, and it is shown that, not only is the surging mode unstable, hut there is also a higher-frequency instability in the post-surging mode. On the basis of the results obtained from routine tests for textured yarns, it is confirmed that the quality of the yarns resulting from both surging and post-surging modes is not acceptable.     

Thermal and mass transport properties of polyester–cotton plated fabrics in relation to back layer fibre profiles and face layer yarn types

Clothing plays an important role in maintaining thermal equilibrium between a human body and the ambient environment by serving as a medium for heat, moisture vapour and liquid moisture transfer. The ability of fabric to maintain this equilibrium is related to thermo-physiological comfort. Plating is an innovative knitted fabric production technique to obtain bi-layered fabrics. An attempt has been made to engineer plated knit structures with such a combination of fibre cross section in the back (inner/next to skin) and the yarn type in the face (outer) layer, so that a rapid liquid transfer from back layer by wicking and quick liquid absorption and evaporation by the face layer can be achieved. Plated fabrics using the combination of triangular polyester fibre in the back and carded cotton yarn in the face layer showed the higher thermal resistance, higher absorbent capacity and would be warmer to the initial touch. However, the combination of combed cotton yarn with triangular polyester fibre resulted in fabrics with the higher air permeability, moisture vapour transmission rate and transplanar wicking.