Fiber Yarn Research Articles

Numerical and Experimental Investigation on Bending Behavior for High-Performance Fiber Yarns Considering Probability Distribution of Fiber Strength

The performance of fiber-reinforced composite materials is significantly influenced by the mechanical properties of the yarns. Predictive simulations of the mechanical response of yarns are, thus, necessary for fiber-reinforced composite materials. This paper developed a novel experiment equipment and approach to characterize the bending behavior of yarns, which was also analyzed by characterization parameters, bending load, bending stiffness, and realistic contact area. Inspired by the digital element approach, an improved modeling methodology with the probability distribution was employed to establish the geometry model of yarns and simulated bending behavior of yarns by defining the crimp strain of fibers in the yarn and the effective elastic modulus of yarns as random variables. The accuracy of the developed model was confirmed by the experimental approach. More bending behavior of yarns, including the twisted and plied yarns, was predicted by numerical simulation. Additionally, models revealed that twist level and number of plies affect yarn bending properties, which need to be adopted as sufficient conditions for the mechanical analysis of fiber-reinforced composite materials. This efficient experiment and modeling method is meaningful to be developed in further virtual weaving research.

Composites Containing Felt Wastes from the Automotive Industry

(One) Background: Using textile waste materials in composites is a well-known problem and is frequently addressed by various scientific teams. Most of this work concerns textile waste introduced into composites as yarn strands. The present work focuses on adding textile wastes prepared in the form of single filaments of yarn spun to fluff, which was produced from waste felt materials from the automotive industry. (Two) Methods: The material was extracted from the bulkheads of worn-out vehicles, serving as thermal and acoustic insulation. The waste was shredded to form single yarn fibres with a fibre diameter of 0.08–0.3 mm and a 2–8 cm length. The shredded waste was used as a filler and modifier for composites. Four test batches were produced with different recyclate contents. A traditional cementitious composite without additives was used as a comparison material. (Three) Results: Composites filled with 3% felt waste have 23.31% lower density (1.71 g/cm3), 71.03% higher absorbability (21.58%), 49.58% lower tensile strength (19.86 MPa), and 53.55% lower compressive strength (3.64 MPa) than traditional composites. Partitions made of these composites had much higher thermal insulation than traditional composites. Composite made of 1% waste was resistant to the phenomena of thermal spalling. Moreover, the spot flame loading did not damage the composite, and there were no scratches or defects. (Four) Conclusions: The tests proved that the waste felt materials could potentially be used as fillers and modifiers in lightweight composites with higher thermal insulation. The addition of felt fibres improves the resistance of the composite to local spalling.

Study on the influence of drafting forms in front drafting zone of ring spinning frame on fiber motion and yarn quality

Double apron drafting is the general drafting form in the front zone of the ring spinning frame. In the double apron drafting system, the top apron and the bottom apron form an elastic tensor gauge, which can better control the movement of floating fibers and improve yarn quality. In order to investigate quantitatively the influence of the top apron and bottom apron on fiber movement and yarn quality in the double apron drafting system, the differences of fiber acceleration point distribution, yarn irregularity and yarn strength spun by double apron drafting, single apron drafting and simple roller drafting under different process conditions were compared. Compared with simple roller drafting, double apron drafting and single apron drafting can effectively control the fiber movement in the drafting zone. With the increase of fiber length, the difference between the distribution of fiber acceleration points obtained by double apron drafting and that obtained by single apron drafting gradually decreases. When the fiber length is greater than 32 mm, the difference is small. Besides, by analyzing the improvement rate of the top apron and bottom apron on yarn irregularity and yarn strength under different drafting settings, it was found that the overall improvement rate of the bottom apron on the yarn quality was higher than that of the top apron, especially for manmade fiber yarns. Even in some cases, the strength of viscose yarn spun by the single apron drafting process is higher than that of the double apron drafting process.

Modeling of yarn strength and its influencing factors in the pneumatic splicing process

Yarn splicing strength is one of the most important indexes to evaluate yarn twist quality, and it determines final performance of the yarn. This paper establishes a prediction model of yarn splicing strength. The strength prediction model was used to predict the mechanical properties of yarn composed of different fibers during splicing. The effects of fiber properties, splicing and tensile strain on the splicing strength of yarn were described by using the characteristic parameters of the fiber and yarn. Finally, the interaction between parameters is analyzed by charts, and the optimal solution is obtained. The results show that the yarn splicing strength prediction model established by the mechanical analysis and geometric structure can reflect the mechanical state of the yarn in the pneumatic splicing chamber, and can be used to calculate the yarn splicing strength. Yarns with higher tensile modulus will obtain higher splicing strength under the action of lower twist and higher tensile stress. Therefore, the strength prediction model provides a theoretical basis for the study of the relationship among yarn strength and fiber properties, splicing, tensile strain and other parameters, and also provides guidance for the optimization of the modern spinning process. Furthermore, the influence of air pressure on the splicing strength is also discussed.

A flexible all-solid-state symmetric supercapacitor with 1.6 V high voltage window was designed by in situ growth of α-FeOOH based on carbon fiber yarn

A flexible all-solid-state symmetric supercapacitor with 1.6 V high voltage window was designed by in situ growth of α-FeOOH based on carbon fiber yarn

A defect detection system of glass tube yarn based on machine vision

Tube yarn is also called glass fiber spun yarn. Due to the excellent properties of glass fiber, various industrial products based on glass fiber are used in a variety of industries. As the most obvious factor affecting the quality of products, quality detection of glass fiber yarns is very important for companies. Due to traditional defect detection relies on the experience and subjective factors of workers, which makes many different views on the same defect. Some traditional methods limit the solution to specific types of defects and do not accurately detect various defects. In this paper, we propose a comprehensive defect detection system of tube yarn via combining machine vision and deep learning methods. In whole system, we inspect the weight through a weight sensor firstly. Then, we propose a multi-scale cross-fusion attention module to improve the MobileNetV2, and combine with machine vision image feature extraction method for hairiness detection. Finally, the modified MobileNetV2 network is used as the backbone of YOLOX network, making the YOLOX is lighter and achieve more efficiently stain detection of tube yarn. Then, the detection results are used to determine whether the glass tube yarn has passed. In addition, we establish an effective and sufficient amount of tube yarn defects dataset. The experimental results show that the proposed hairiness detection algorithm achieve 96% accuracy with 160+ FPS, and the surface stain detection algorithm achieve 0.89 mAP with 71+ FPS on the tube yarn dataset. The system is efficient, precise, and can be applied to actual production.

NUMERICAL MODELLING OF TEXTILE STRUCTURES: POTENTIAL AND LIMITS

Numerical modelling, namely finite element modelling, is a standardised tool in many branches of engineering. In textile engineering, due to the complexity of the structure, many limitations occur in using this approach. Despite the limitations the finite element modelling of textiles has huge potential for the future. This contribution deals with FE modelling of tensile test in wale and course direction of single jersey knitted fabric. The meso level of the structure was chosen for the model, so it could be possible to track the behaviour of yarn interlacement during the simulated deformation. The virtual model was created according to parameters of single jersey knitted fabric sample, which was produced from polyester monofilament. By using monofilament instead of staple yarn, contacts between fibres in yarn could be excluded in FE model preparation. Two different computational programs were used for simulations – MSC Marc Metant for implicit computing approach and ANSYS LS-DYNA for explicit computing approach. The results from implicit and explicit solver were compared and discussed. Validation of models was done and results were included in the discussion. Due to big deformations of textiles, explicit solver appears to be more suitable for finite element modelling in textile engineering.

In vitro experimental study on effect of fiber denier, yarn doubling, and specialty treatments on physical and thermal behaviors of knitted sports socks

Knitted sports socks remain in continuous scuff with wearers’ feet and shoes during activities. Such continuous physical contact governs severe pills on socks surface, which is unpleasant for both the wearer and the working life of socks. Hence it becomes necessary to take measures for controlling fabric deterioration, that is, anti-pilling treatments. Though pilling performance is enhanced; however, thermal comfort characteristics are compromised through the treatments. Simultaneous acquirement of both pilling and thermal characteristics is an area of interest. Fiber denier and yarn doubling techniques are among the influential factors in the solution to the problem. Specimens have been developed using four different fiber deniers, two yarn doubling conditions, and two specialty wet treatments under a full factorial experimental design. Results showed a significant variation in pilling behaviors and thermal characteristics before and after treatments in the statistical analysis, predicting the possible stages, that is, a combination of experimental factors for desired characteristics attainment.

Study the state of deformation of fibers with variable properties

The method for calculating the tensile and compressive strength of certain fiber systems with different structures in terms of layer thickness was presented. The laws of influence of various parameters, which become invisible in stretching, have been established on the description of two-layer yarn interaction. It was found that the tension (pressure) compressing the fiber in the center of the thread has a maximum value, it increases significantly with the increase of the angle of attack, which leads to an uneven distribution along the radius of the thread. In a two-layer yarn formed from two fiber systems with different mechanical characteristics, the degree of compression of the fibers depends significantly on the ratio. It was expected that the fiber maturity index decreased in the outer layer, and the pressure between the fibers increased as the thickness of the inner layer increased. All the fibers in the two-layer yarn are in a sliding state, and as this indicator increases, starting from the center of the yarn, the fibers begin to be in tight contact with each other, the length of which depends on the radius of the inner layer, the bending angle, and the ratio of the Young's modulus of the fibers of the two-layer yarn. It was observed that the fibers in the thread layer are in tight contact with each other at the value of the angle of sag

SURFACE ROUGHNESS OF POLYAMIDE KNITTED FABRICS

Fabrics are never ideally smooth. Their texture varies between fine and coarse, quantified through the surface’s vertical deviation. Fabric roughness, or its opposite smoothness, is employed as measure of the surface texture of fabrics. In general, texture depends upon fiber properties, yarn count, yarn twist, and fabric structure and fabric design). This research aims to determine the limitations in visual perception of surface roughness in comparison to objective surface roughness measurements of low weight polyamide fabrics. Subjective evaluation is used for the visual assessment, while instrumental measurement of the properties was conducted using a noncontact laser profilometer. Subjective evaluation was conducted by a panel of forty untrained evaluators on a sample of seven polyamide knitted fabrics with different yarn count and composition. The roughness profile parameters were measured using Talysurf CLI 500 according to ISO 4827. Although the surface roughness measured as arithmetic mean deviation (Ra) and roughness through visual inspection of the fabric are correlated, instrumental measurements of roughness are more precise. Differences in the surface roughness arising from significantly different yarn structures will be observed, while those due to the knitted fabric structure are negligible in visual inspection.

Fatigue life prediction of 3D braided carbon/carbon composites with braided angle variation at elevated temperature

The braiding angle of 3D braided carbon/carbon composites (C/CCs) will change during high temperature fatigue loading, which will affect the fatigue properties of 3D braided C/CCs. In order to realize this dynamic simulation in the high temperature fatigue life prediction of 3D braided C/CCs and further improve the prediction accuracy of high temperature fatigue life of 3D braided C/CCs, a high temperature fatigue life prediction model of 3D braided C/CCs considering the change of braiding angle with fatigue cycle number was established. The establishment of the prediction model mainly includes: a meso-scale representative volume elements (RVEs) of 3D braided C/CCs considering yarn direction and fiber bundle cross-section shape is established at the meso-scale; the high temperature residual stiffness and residual strength models of fiber bundles considering high temperature and stress level are established. Based on the experimental data characteristics of high temperature fatigue residual stiffness of 3D braided C/CCs, a mathematical model of cycle number/braided angles (CN/BAs) is established. The fatigue life prediction model was used to predict the 3D braided C/CCs at 700°C and stress levels of 87% and 85%. The results showed that the prediction error of single flower node was less than 5%. The fatigue life prediction error is less than two times the tolerance.

Influence of displacement rate in the tensile testing of dry yarns for composite materials used in masonry strengthening

One of the most recent strengthening techniques of masonry structures involves fibre-reinforced polymer (FRP) grids as internal reinforcement of mortar plasters to produce what is normally referred to as Composite Reinforced Mortar (CRM) systems. The behaviour of such systems relies on the performance of the FRP grids which in turn depends on the properties of their constituents (fibres and resin).By comparing results of tensile tests at different displacement rates on glass fibre yarns, the effects of the strain history on the strengths exhibited by such products is here investigated. Further tensile tests were then performed on glass FRP grids made of the same previously analysed yarns in their warp direction and the influence of the displacement rates again studied.The analysis of the results of the performed experimental activity allows studying the influence of strain rates on the mechanical properties and failure behaviour of both yarns and their relative composites.

Automatic Modeller of Textile Yarns at Fibre Level.

This paper presents a geometrical modelling principle for the modelling of yarns at the fibre level. The woven and the knitted textile structures are built of yarns, which on the other side, are fibrous assemblies. In many yarn and fabric modelling works, yarns are considered as a single line element; however, most yarns are composed of a number of staple or filament fibres. It is then very important to understand the yarn at the micro level for a better understanding, production and application of the above structures. The current paper aims to present the modelling and implementation of yarn structures at the fibre level using the algorithmic geometrical modelling principle. The research work uses basic assumptions for the building of the models and various implementation issues, connected with the proper representation of the single multi-filament yarns, plied yarns and finally the staple fibre yarns. Except for visualization, the generated yarn models are prepared as a basis for mechanical, thermal, fluid flow and other simulations of textile structures using FEM, CFD and other numerical tools.

Investigation on the effect of cotton-tencel (50:50) siro yarn twist multipliers on fabric stiffness

The properties of fabrics are mainly affected by constituent fiber properties and yarn structures. The yarn structures are primarily dependent on the spinning technique. The twist multiplier is a leading factor influencing yarn structure which directly correlates with fabric stiffness and mechanical properties due to structural behavior. In this study, siro spun yarn has been prepared using different twist multipliers (3.6, 4, 4.4, and 5.0) by blending cotton and tencel fiber at the spinning stage to investigate the effect of twist multipliers on fabric stiffness and the flexural rigidity of woven fabrics. The 1/1 plain, 2/2 twill, and 8-end satin fabrics have been woven using prepared yarns in warp and weft directions. The fabric stiffness has been measured using the ASTM D1388-2018 method. The results reveal that fabric stiffness increased with the increasing twist multiplier. Furthermore, a comparative study on different weave structures shows significant differences in stiffness. Overall, the experimental results present a close relationship between twist multiplier, spinning triangle, float length, fabric stiffness, and rigidity, and also show the optimum twist level for cotton-tencel siro yarn to attain maximum stiffness and strength.

Dual structure engineering of SiOx-acrylic yarn derived carbon nanofiber based foldable Si anodes for low-cost lithium-ion batteries.

Silicon (Si) is attracted much attention due to its outstanding theoretical capacity (4200 mAh/g) as the anode of lithium-ion batteries (LIBs). However, the large volume change and low electron/ion conductivity during the charge and discharge process limit the electrochemical performance of Si-based anodes. Here we demonstrate a foldable acrylic yarn-based composite carbon nanofiber embedded by Si@SiOx particles (Si@SiOx-CACNFs) as the anode material. Since the amorphous SiOx and carbon (C) coating on the outside of the Si particles can provide a double buffer for volume expansion while reducing the contact between the Si core and the electrolyte to form a thin and stable solid electrolyte interface (SEI) film. Simultaneous in-situ electrochemical impedance spectroscopy (in-situ EIS) and galvanostatic intermittent titration technique (GITT) tests show that SiOx and C have higher ion/electron transport rates, and in addition, using acrylic fiber yarn and Zn(Ac)2 as raw materials reduces the manufacturing cost and enhanced mechanical properties. Therefore, the half-cell can achieve a high initial Coulombic efficiency (ICE) of 82.3% and a reversible capacity of 1358.2 mAh/g after 180 cycles. It can return to its original shape and remain intact after four consecutive folds, and the soft-pack full battery can also light up LED lights under different bending conditions.

Research on reuse of standing dye bath of reactive dye

The aim of the work was to find out suitable method of dyeing so that costly reactive dye bath can be reused without draining them. Because of the hydrolysis of residual reactive dyes due to the fixation conditions and because of relatively large amounts of dyes and salts left in the effluent, reusing hydrolyzed reactive dyes is a challenge to dyers. Two reactive dyes were examined (reactive red, reactive yellow and two fabrics: nylon, silk as well as silk fiber and nylon yarn). When using suitable dyeing conditions by controlling pH and temperature, hydrolyzed reactive dye baths for silk and nylon dyeing showed very good wash and moderate colorfastness.

KAJIAN MOTIF BATIK GONGGONG CV LAWANA DI TANJUNG PINANG

Gonggong CV Lawana in Tanjung Pinang using a textile design method approach. This research is formulated in one question "How is the design of the Batik Gonggong motif in the Production of Batik Gonggong CV Lawana, Tanjung Pinang with a textile design method approach through aesthetic, material, process, function, and fashion aspects?". This research uses a descriptive qualitative research method with a textile design method approach. Data analysis techniques using interactive analysis models include data reduction, data presentation, and concluding. The results of the research reveal the stages that are passed in designing based on aesthetic aspects, materials, process functions, and supporting aspects, namely fashion. (1) The aesthetic aspect that is considered in the main and supporting motifs, especially the main motif of Batik Gonggong CV Lawana has identical characteristics with the character of a snail shell that bulges in its belly. (2) The material aspect is a consideration in selecting the type of yarn fiber, the structure of the weave, nature and absorption capacity or suitability of the fabric as well as the different alternative fabrics for stamped and written batik products. (3) The process aspect of Batik Gonggong begins with determining the design from the main source of inspiration, the shell of the barking snail, the design will go through a sublimation process, then continue to be produced in certain quantities. (4) Functional aspects are related to consumers who use the product as a choice of use, as regional souvenirs, uniforms, and fashion. (5) The fashion aspect is found in the development of motifs through three periods ranging from natural suggestion patterns, creative patterns, and combined patterns. The development of the coloring technique, namely gradation is done by brushing using a sponge with a combination of giving light and dark colors which when soaked will fade and produce a gradation effect.

A novel technique to simulate and characterize yarn mechanical behavior based on a geometrical fiber model extracted from microcomputed tomography imaging

Textiles and their production machines are increasingly designed using simulations of the textile production process. These simulations require reliable structural yarn models. In practice, these models are often based on simplifying assumptions concerning the underlying geometry. However, in recent years more realistic geometrical fiber models have been developed, but have not been used to estimate the structural properties of yarns. The current contribution presents a new methodology to obtain a structural yarn model through numerical simulations based on a high-fidelity geometrical yarn model. Starting from microcomputed tomography data of a real-life natural fiber yarn used in air-jet weaving, a geometrical yarn model is constructed by tracing the individual fibers. This geometry is then incorporated in a computational finite-element analysis framework to obtain the yarn tensile and bending behavior through a simulated tensile test and Peirce cantilever test. Finally, the results are validated by comparison with experimental data. It is shown that this new technique succeeds to estimate the tensile and bending behavior. The presented methodology allows one to gain fundamental insight into the internal deformations and stresses in the yarn. Moreover, it is an important first step toward statistical studies on the structural yarn behavior on the microscale level and toward homogenized macro-models originating from a fully digital workflow.

Unraveling of the laser drilling of carbon/carbon composites: Ablation mechanisms, shape evolution, and damage evaluation

Laser machining is promising in shaping the brittle carbon/carbon composites (C/Cs) with deep holes, sharp edges, or thin walls. However, there are still many unknowns relating to the laser ablation of carbon materials, and the existing theory and practice is insufficient to guide the industrial machining of C/Cs. Herein the laser drilling of C/Cs was experimentally conducted and numerically modeled to probe into the mechanisms responsible for the material removal, surface formation, and damage evaluation. Firstly, the intrinsic correlations among the anisotropic hole feature, the fiber yarn alignment and the steady-state thermal conduction are revealed. The detailed characterizations of the ablated surface and the recast layer clearly prove that sublimation of the graphitic carbon dominates the material removal process under laser ablation. Furthermore, it is proposed that the greater portion of crystalized graphene layers enables the lower ablation rate of the pyrocarbon matrix than the carbon fibers. Secondly, the combination of the experimental and simulated results unravels that the continuously evolved surface slope and the redeposited recast layer are the decisive factors in the laser-carbon interaction, which affect the efficient absorption coefficient of the laser and result in the nonlinear drilling rate and the self-limiting of the drilling. Finally, the roles of the laser heating and the subsequent rapid cooling in damage initiation and propagation are identified: nanoscale splitting of the pyrocarbon occurs due to the growth and realignment of the graphene layers upon laser heating, and the tensile thermal stress induced by the cooling drives the further growth of high-density but discrete microcracks from these splitting sites. The load bearing capability of the carbon fibers, however, is retained in this severe thermal shock. As a result, the laser drilling induces only a slight degradation of the mechanical strength of the C/Cs.

Damage mechanisms of 2.5D SiO2f/SiO2 woven ceramic matrix composites under compressive impact

Fiber-reinforced SiO2f/SiO2 woven ceramic matrix composites (CMCs) are widely applied in the aeronautics and astronautics field due to their many physical and chemical advantages. However, compressive impact loads affect many application scenarios; thus, the damage morphologies and failure modes of these composites under compressive impact should be studied, particularly in the through-thickness direction. In this study, a comparative analysis using the split Hopkinson pressure bar (SHPB) experiment and finite element analysis (FEA) model revealed the damage mechanisms. The compressive impact was simulated in Abaqus/Explicit, and the cohesive element was selected to simulate cohesion of the interface according to the Hashin criterion for multi-mode failure. The results show that 2.5-dimensional SiO2f/SiO2 woven CMCs do not have sufficient plasticity to restrain the propagation of micro-cracks under high strain rates after the elastic stage under compressive impact. Many micro-cracks propagated and formed large cracks in the adiabatic shear zone. The adiabatic shear zones were generated when a compressive impact load was applied to the SiO2f/SiO2 CMCs at a high strain rate, and these impacts deformed the SiO2f/SiO2 CMCs. The adiabatic shear zone occurred at a high strain rate at the weakest point inside the fields of the SiO2f/SiO2 CMCs. The micro-cracks propagated and accumulated in this zone. Plastic fracture is the major failure mode for the SiO2f/SiO2 CMC specimens; this failure was characterized by fiber yarn fracture and the formation of micro-voids and micro-cracks due to matrix fracture. The large cracks, new voids, and interfacial debonding lead to the failure of the SiO2f/SiO2 CMCs. Combined action due to micro-crack formation and its propagation in the adiabatic shear band leads to a softening mechanism of the strain rate.