Yarn Tensile Properties Research Articles

Dref-3 yarn structure with plied staple fibrous core

PurposeDref-3 friction spun core yarns produced using staple fibre yarn as the core, e.g. Jute core yarn wrapped with cotton fibre, have poorer mechanical properties compared to the core yarn itself. The purpose of this study was to understand the structure of such yarns, that will lead to the optimization of fibre, machine and process variables for production of better quality yarn from the Dref-3/3000 machines.Design/methodology/approachThe Dref spinning trials were conducted following a full factorial design with six variables, all with two operative levels. The Dref-3 friction spun yarn, in which the core is a plied, twisted ring yarn composed of cotton singles and the sheath, formed from the same cotton fibres making the singles, has been examined. The structures have also been studied by using the tracer fibre technique.FindingsIt was observed that rather than depending on the plied core yarn, the tensile properties of the Dref-3 yarn are significantly determined by the parameters those affect the constituent single yarn tensile properties, i.e. the amount of twist and its twist direction, yarn linear density and the sheath fibre proportion used during the Dref spinning in making the final yarn. Further, when the twist direction of single yarn, double yarn and the Dref spinning false twisting are in the same direction, the produced core-sheath yarn exhibits better tensile properties.Practical implicationsThe understanding of the yarn structure will lead to optimized production of all staple fibre core Dref spun yarns.Social implicationsThe research work may lead to utilization of coarse and harsh untapped natural fibres to the production of value-added textile products.Originality/valueThough an earlier research has reported the effects of sheath fibre fineness and length on the tensile and bending properties of Dref-3 friction yarn, the present study is the first documented attempt using the tracer fibre technique to understand Dref-3 yarn structure with plied staple fibrous core.

Effect of interface on composites made from DREF spun hybrid yarn with low twisted core flax yarn

In the present work, the influence of interface and hybrid yarn structure on flax-PP based unidirectional composite properties have been studied thoroughly. Flax-PP based core-sheath structured DREF spun hybrid yarns are manufactured after varying the core yarn twist and sheath percentage at three different levels and using MAgPP treated and untreated flax yarn as core. These hybrid yarns are consolidated to manufacture unidirectional composite samples and the resultant composites are tested accordingly. It is observed that MAgPP treatment of the core flax yarn improves the tensile and flexural properties of the hybrid yarn reinforced unidirectional composites while impact strength decreases after the treatment. A negative impact on the tensile and flexural properties of the unidirectional composite samples is observed with increasing core twist and sheath content of the reinforcing hybrid yarn. The impact strength of the composite samples increases for similar changes in hybrid yarn parameters.

The Effect of Count, Twist, Opening Roller Speed and Rotor Speed on Yarn Tensile Properties of Rotor Spun Yarns

Tensile properties are some of the important parameters when considering the quality of rotor spun yarns. This research work set out to investigating the effect of four factors namely count, twist, opening roller speed and rotor speed on the tensile properties of rotor spun yarn. Taguchi Experimental Design was used to study the influence of the four factors on yarn tensile (strength and elongation) properties. The experiments were carried out in a textile factory in Uganda. The results obtained in this research work indicated that both single and combined effects of the selected factors significantly affected yarn strength and elongation. For the given cotton lint, optimum tensile properties could be obtained at 15Ne, 5TM, 8000 rpm and 90,0000 rpm for count, twist, opening roller speed and rotor speed respectively.

Tensile behavior of staple fiber yarns part III: comparison of mathematical models

Despite the development of artificial neural network and computer simulation models that predict yarn tensile properties, the mathematical model is still very important being the base for all models. In this research, three mathematical models have been applied for evaluation of coefficient of fiber strength utilization in staple spun yarns before break at same value of yarn strains. The experiments were conducted on cotton, viscose and polyester fibers, and yarns. The results indicated that our model exhibited least prediction error followed by Pan’s and Frydrych’s models for cotton and viscose but for polyester, Pan’s model produced least error followed by Frydrych’s model and our model. The superiority of our model might be resulted from the introduction of the phenomena of fiber directional distribution in the staple spun yarns.

A Study on Physical Properties of Microfilament Composite Yarns

In the textile industry, composite yarns with multifilament cores are used to impart strength. There are various spinning systems to produce composite core-spun yarns. In this study, to determine the effects of filament fineness on yarn characteristics of composite yarns, polyester filaments with medium, fine and micro fiber linear densities were used as the core portion and cotton fiber was used as the sheath material. Yarn samples were manufactured using a modified ring spinning system with four different yarn counts and constant twist factor (ae). The effect of filament linear density on yarn tensile properties, unevenness and imperfections was determined. Yarn evenness and tensile properties were compared with 100% cotton ring spun yarn and to each other. When relative amount of core increases, it was observed that composite yarns had improved tenacity and elongation compared to 100% cotton ring spun yarn. Although filament fineness was found to have a significant effect on the CVm % properties, there was no statistical effect on imperfections other than yarn count parameter.

A study on the impact of hair wrappings on yarn properties – Part I: Theoretical analysis and manual experimental validations

Hair-wrapping distribution, hair-wrapping direction and yarn moving direction models have been developed to analyze and predict the impact of hair wrappings on yarn properties in theory. Then, Nm 48 ring-spun ramie yarns were respectively treated by various manual hair wrappings, such as the forward diagonal, the forward vertical, the forward random, the backward diagonal, the backward vertical and the backward random. The results showed that the various hair-wrapped yarns had a similar smoothened static surface appearance. Although vertical hair wrappings caused the highest deterioration in yarn unevenness and imperfections, they kept the smallest change of hairiness among all types of hair wrappings during yarn moving. Hair wrapping contributed to large fiber utilization, improving yarn tensile properties, regardless of the worsened yarn unevenness and imperfections. The manual experimental results corresponded well to our modeling suppositions and theoretical analysis.

The Influence of LiCl/DMAc Microdissolution Treatment on Tensile Property of Hemp/Cotton Blended Yarn

ABSTRACTTo discuss the influence of different activation and microdissolve methods for the tensile properties of hemp/cotton blended yarns. The steps are as follows, treated fabrics and hemp fibers with pretreatment and LiCl/DMAc microdissolution, fibers were analyzed by FT-IR and XRD methods, tensile properties of yarns were tested by Instron. The result shows that the main groups have no obvious changes in fibers, cellulose derivative reaction has not been found during microdissolution. The yarns’ breaking force increases and elongation decreases in different degrees except craft one, the greatest increase of the breaking force of treated yarns reached 46.4%.

Investigation of Tensile and Stiffness Properties of Composite Yarns with Different Parameters

Investigation of Tensile and Stiffness Properties of Composite Yarns with Different Parameters

Prediction of Blended Yarn Evenness and Tensile Properties by Using Artificial Neural Network and Multiple Linear Regression

Abstract The present research work was carried out to develop the prediction models for blended ring spun yarn evenness and tensile parameters using artificial neural networks (ANNs) and multiple linear regression (MLR). Polyester/cotton blend ratio, twist multiplier, back roller hardness and break draft ratio were used as input parameters to predict yarn evenness in terms of CVm% and yarn tensile properties in terms of tenacity and elongation. Feed forward neural networks with Bayesian regularisation support were successfully trained and tested using the available experimental data. The coefficients of determination of ANN and regression models indicate that there is a strong correlation between the measured and predicted yarn characteristics with an acceptable mean absolute error values. The comparative analysis of two modelling techniques shows that the ANNs perform better than the MLR models. The relative importance of input variables was determined using rank analysis through input saliency test on optimised ANN models and standardised coefficients of regression models. These models are suitable for yarn manufacturers and can be used within the investigated knowledge domain.

Effects of metal filament’s alignment on tensile and electrical properties of conductive hybrid cover yarns

AbstractOf late, a significant amount of research has been carried out using metals for conductive fabrics and composites to obtain the desired level of electromagnetic shielding along with physical and mechanical properties for its durability. However, incorporating these metallic filaments as core or as an integral part of core deteriorate the mechanical properties of textile yarns and ultimately the fabrics’. Moreover, the transparency of fabrics to high frequency/smaller wavelength waves further increases with the attempt to increase the metallic filament diameter. This study, therefore analyses the effects of metallic filament alignment in order to improve the mechanical properties of the resultant hybrid yarns, and devises an alternative method to increase the amount of conductive filament without increasing the diameter of the conducting wire in hybrid yarn structures. The results suggest that the tensile properties of the proposed hybrid cover yarns with conductive filament as covering component is superior as compared to the yarns having a conductive filament in the core, however, the electrical resistance increases with an increase in conductive filament length. The tenacity, elongation and initial modulus values were enhanced several times by incorporating the conductive filament as spiral covering. Moreover, with the proposed alignment method, the amount of copper in hybrid yarn can be increased up to some extent by changing the number of turns of covering component.

Ozonation: a Green Source for Oxidized Cotton

Research was carried out on the oxidation of cellulose by ozone treatment. It is considered as environment friendly in comparison with the existing oxidation methods used in industry for a long time. This treatment is used in different applications such as the scouring / bleaching of cotton fabrics and in improving the properties of Kraft pulp cellulose in the paper industry. In this study, the effect of Ozone treatment on cotton yarn properties was investigated. This investigation can help in obtaining the maximum crystalline percentage of cotton for the production of nano-crystalline cellulose. Two-ply cotton ring spun yarn was treated with ozone gas for different time periods. Yarn tensile properties, wickability, the copper number and physical appearance were observed. It is evident that yarn tensile properties deteriorate drastically after a certain time, while the wickability and copper number increase simultaneously. n Material and method In this study, cotton fibres (Medium Sta ple Pakistan Cotton) with average values of 28 mm staple length and 1.65 dtex (fi bre linear density) were used to produce 25.5 tex ring spun yarns with 711 t.p.m. (Z twist). Afterwards these single yarns were folded and twisted to produce twoply yarn with 364 t.p.m. (S twist). 8 yarn samples, 0.5 grams each, were mounted separately on special stainless steel holders and kept in closed containers filled with the ozone gas. The setting of the ozone generator - „TRIOTECH GO 5LAB-K” (Czech Republic) was kept same for all samples: 1.5 minutes for the ozone charging time, and 4.5 mg/litres of ozone gas. The samples were kept in their containers for different time periods and then taken out according to the plan shown in Table 1.

Tensile fatigue behavior of polyamide 66 nanofiber yarns

Nanofiber yarns with twisted and continuous structures have potential applications in fabrication of complicated structures such as surgical suture yarns, artificial blood vessels, and tissue scaffolds. The objective of this article is to characterize the tensile fatigue behavior of continuous Polyamide 66 (PA66) nanofiber yarns produced by electrospinning with three different twist levels. Morphology and tensile properties of yarns were obtained under static tensile loading and after fatigue loading. Results showed that tensile properties and yarn diameter were dependent on the twist level. Yarns had nonlinear time-independent stress–strain behavior under the monotonic loading rates between 10 and 50 mm/min. Applying cyclic loading also positively affected the tensile properties of nanofiber yarns and changed their stress–strain behavior. Fatigue loading increased the crystallinity and alignment of nanofibers within the yarn structure, which could be interpreted as improved tensile strength and elastic modulus. POLYM. ENG. SCI., 55:1805–1811, 2015. © 2014 Society of Plastics Engineers

Property Analysis of Stainless Steel Fiber (Yarn) and its Effect on Knitting Process

In this paper the frictional and tensile properties of stainless-steel fiber, cotton fiber, polyester fiber and rayon fiber, as well as the tensile and surface hairy properties of stainless-steel yarn, cotton yarn and wool yarn were tested and compared. Experimental results shown that the stainless-steel fiber has greater density, friction coefficient and tensile breakage strength but smaller breaking elongation. On the basis of summarizing the differences between stainless-steel fiber (yarn) and conventional textile fibers (yarns), difficulties occurred during knitting process were analyzed and the corresponding solutions were proposed.

Influence of GA-BP Artificial Neural Network Based on PCA Dimension Reduction in Yarn Tenacity Prediction

The fiber characteristics directly affecting the yarn tensile properties are analyzed and the features of GA-BP artificial neural network are presented. Based on the interrelationship among the fiber characteristics, which could led to a worse predicting result, Principal component analysis (PCA) is adopted to solve this problem. 12 characteristics of cotton fiber tested by HVI or AFIS and yarn process parameters, such as combing, degree of twist, yarn count, was preprocessed by this method and 10 independent comprehensive indexes are induced and substituted into GA-BP artificial neural network as input factors. For further comparison, the 10 dimension reduced indexes and the 15 initial variables are respectively introduced into the GA-BP and BP artificial neural network to develop 4 prediction models. By comparing the accuracy in predicting yarn tenacity, it is concluded that GA-BP model has higher accuracy than BP model, and the dimension reduced indexes based on PCA would decrease the accuracy in prediction instead. So, blindly using PCA method for reducing the complex correlation among input variables was not helpful for the prediction accuracy.

Investigations of fiber twist on the mechanical properties of sisal fiber yarns and their composites

The effect of fiber twist on the tensile properties of single sisal fibers was investigated by single fiber tensile test. Four kinds of sisal yarns with four different levels of twist were made and the mechanical properties were investigated on both unimpregnated and resin-impregnated sisal yarns. A critical fiber twist level for unimpregnated sisal yarns was found beyond which the tensile properties started to decrease with the increasing of the level of fiber twist. However, for resin-impregnated sisal yarns, both tensile strength and modulus decreased with the increasing of the fiber twist level. In addition, the effect of fiber twist on both the tensile and flexural properties of unidirectional sisal yarn reinforced composites was studied. It was shown that lower twist level led to higher mechanical properties of its reinforced composites. Compared with the experimental results, Rao’s model proved to accurately calculate the Young’s modulus of fiber yarns with different levels of twist. Thus, the Young’s modulus of sisal yarn reinforced composites could be predicted by the rule of mixtures hereafter.

A comparative study on chemical treatment of jute fiber: potassium dichromate, potassium permanganate and sodium perborate trihydrate

Studies have been carried out on chemical treatments of jute fibers in order to hinder moisture absorption, which causes incompatibility with a non-polar polymer, and to increase the surface roughness for mechanical interlocking. The objective of this research is to improve the interfacial adhesion between jute fibers and polypropylene by oxidative treatments. On this basis, jute fibers were treated with potassium dichromate (PD), potassium permanganate (PM) and sodium perborate trihydrate (SP). Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy were used to characterize jute fibers. The effects of chemical treatments were also revealed by assessment of moisture absorbability, yarn tensile properties and interfacial shear strength with polypropylene. FTIR and XPS analyses confirmed oxidative modification of jute fibers using any of the surface treatments. It was observed that the proportion of O=C groups increased, whereas that of O–H groups decreased after oxidative modifications. Tensile strength and elasticity modulus results decreased after oxidative treatments, whereas PD, PM and SP enhanced the interfacial shear strength values by 25, 61 and 71 %, respectively. Only SP treatment influenced moisture absorbability results significantly. The surface roughness of untreated jute fibers shows increments after chemical treatments due to partial removal of surface cementings. According to the findings obtained from surface characterization methods and physical tests, the highest interfacial adhesion with better compatibility with polypropylene was achieved after SP treatment by providing the highest surface roughness values and hydrophobic character of jute fiber.

Studies on Tensile Properties of Eri Silk/Polyester Blended Yarn Using Design of Experiment Methodology

Eri silk is one of the four varieties of silk available in India which has excellent thermal insulation property. With a view to explore its blending possibilities with polyester, manufacturing of eri/polyester blended yarn at different blend ratio in ring spinning system has been successfully performed following drawframe blending technique. The Box and Behnken design of experiment for three variables and three levels has been used to study the influence of count of the yarn spun (Ne), twist multiplier and proportion of eri fibre in the blends on some important tensile properties of the yarns produced. The chosen level of variables remaining within the industrially acceptable limits shows that fibre character and yarn parameters are the determining factors to influence yarn tensile properties. Validity of Hamburger model for the prediction of blended yarn tenacity has also been assessed for the blended yarn produced.

Properties Evaluation of Cotton Ring and Compact Spun Yarns after Scouring and Bleaching Process

Yarn prepared from two technologies i.e. Ring frame and compact spinning system analyzed on Uster Tensorapid, Uster Evenness Tester. It was observed that yarn prepared with compact spinning system gives less variation in end products. Study also reveals that there was significant difference between tensile properties of yarn which was produced from compact spinning and ring spinning. Yarn produced from two technologies pretreated with scouring and bleaching process and structural changes occurred in yarn were analyzed on Uster Tensorapid, Uster Evenness Tester. In the present investigation it was observed that yarn produces from both spinning technique shows, strength reduced and elongation improved in compact spun yarn and count C.V. also found reduced for both systems after scouring and bleaching process. It was noticed that, yarn produced from compact spinning gives less yarn hairiness because of reduction in spinning triangle and protruding fibers were goes into yarn body which gives very good impact on subsequent processes.

Effect of Yarn Structure on Mechanical Properties of Natural Fiber Twisted Yarns and Green Composites Reinforced with the Twisted Yarn

Natural fiber twisted yarn has high potential as a reinforcement of green composites, because the yarn is produced as a continuous form, which is necessary for exhibiting reinforcing mechanism in a composite. In a twisted yarn, spun yarn filaments meander from the twisted yarn surface to inner along the yarn axis. This phenomenon is called ‘migration’, and yarn structural mechanics has been developed by taking an ideal migration into consideration. In the yarn mechanics, yarn tensile properties are often expressed as a function of twist angle, while yarn structure depends strongly on performance of twisting machine. Thus, the present study deals with the effect of twist contraction ratio (TCR), one of the most important parameters in yarn structure, on tensile properties of twisted yarns and green composite reinforced with twisted yarn. Ramie spun yarn filaments were used as a test material, and the twisted yarn were produced using auto or hand twisting machine. The results show that relation between mechanical properties of the twisted yarn and yarn structure can reasonably be comprehended when choosing TCR as an evaluation parameter. Furthermore, this study additionally deals with relation between theoretical elastic modulus, and twist angle or TCR based on the experimental data of green composites as well as twisted yarns.

Direct electrospinning of highly twisted, continuous nanofiber yarns

Yarns are key building blocks to construct complicated fibrous structures for diverse applications. Although carbon nanotube yarns have been fabricated by a few novel techniques, challenges still remain in processing other nano fibrous materials into yarns, especially during the fiber fabricating process. In this paper, we report a simple but efficient and versatile method to prepare well‐twisted continuous nanofiber yarns directly through an electrospinning process. The yarn electrospinning process used two oppositely charged electrospinning nozzles to generate a hollow nanofiber “cone” on an intermediate funnel collector. Continuous nanofiber yarns can be directly withdrawn from the “cone” apex, with up to 7400 turns per meter of twists inserted through the rotation of the funnel. The maximum yarn production rate is 5 m/min, and the yarn twist level and fiber orientation can be controlled by the funnel rotating speed and yarn withdrawal rate. The yarn tensile properties showed dependence on the twist level.