A model on the viscoelastic behavior of sewn knitted fabrics

2019 ◽  
Vol 31 (3) ◽  
pp. 362-375
Author(s):  
Reyhaneh Shekarian ◽  
Sayyed Mahdi Hejazi ◽  
Mohammad Sheikhzadeh
Keyword(s):  
Significant Influence ◽  
Viscoelastic Behavior ◽  
Tensile Creep ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
Retarded Time ◽  
Content Type ◽  
Sewing Thread ◽  
Wide Range ◽  
Thread Tension

Purpose Knitted fabrics have been widely used in a wide range of applications such as apparel industry. Since these fabrics are continuously subjected to the long-term tensile stresses or tensile creep in real conditions, investigation of viscoelastic behavior of sewn knitted fabrics would be important especially at the seamed area. The paper aims to discuss this issue. Design/methodology/approach A lockstitch machine was used to produce sewn samples by knitted fabric. Factors such as stitch per inch (SPI), thread tension and thread type were variables of the model. Tensile creep tests under constant load of 200 N were conducted, and creep compliance parameter D(t) of samples was obtained as a response variable. A successive residual method (SRM) was also used to characterize viscoelastic properties of sewn-seamed fabrics. Findings The instantaneous elastic responses of the seamed samples were less than those of the neat fabric (fabric with no seam). An increase in sewing thread strength increases the instantaneous elastic response of the sample. SPI and thread tension have an optimum value to increase E0. High tenacity polyester thread, due to its higher elastic modulus, caused a larger E0 than polyester/cotton thread in sewn knitted fabric. Characteristics of seam including sewing thread type, SPI and sewing tension have significant influence on T0. Sewn-seamed fabric by high modulus thread shows less viscous strain T0 than the neat fabric (fabric with no seam). Viscous strain T0 decreases as SPI changes from 8 to 4 and/or 12. SPI and thread tension have an optimum value to increase the viscous strain T0. E1 is the same for optimum seamed fabric and fabric sample but T1 is about two times greater for seamed fabric. Retarded time for creep recovery increases by sewing process but characteristics of seam have significant influence on E1 and T1. All sewn knitted fabric samples used in this study could be described by Burger’s model, which is a Maxwell model paralleled with a Kelvin one. Originality/value This paper is going to use a different method named successive residuals to model the creep behavior of seamed knitted fabric. On the whole, this paper paved a way to obtain viscoelastic constants of sewn-seamed knitted fabrics based on different sewing parameters such as the modulus of elasticity of the sewing thread, SPI and sewing thread tension.

Evaluation of the air permeability of elastic knitted fabrics and their assemblies

2018 ◽  
Vol 30 (6) ◽  
pp. 839-853 ◽  
Author(s):  
Virginija Daukantiene ◽  
Giedre Vadeike
Keyword(s):  
Significant Influence ◽  
Thickness Measurement ◽  
Air Permeability ◽  
Dominant Factor ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
New Approach ◽  
Content Type ◽  
Fabric Thickness ◽  
Permeability Property

Purpose The purpose of this paper is to evaluate the air permeability of knitted fabrics containing elastane fibre and their seams applying both the new approach based on fabric thickness measurement at different pressures and standard method. Design/methodology/approach Investigations were performed with commercially available eight polyester knitted fabrics containing different elastane yarn proportion. Bonded seams were laminated applying the urethane thermoplastic adhesive film of 0.175 mm thickness. Bonds were laminated by heat at 5.6 kPa pressure applying pressing device GTK DEA 25 R at 140°C temperature for 40 s duration. Sewn seams were assembled with 607 covering chain stitch applying 5.0 stitches per cm density and 512 overedge chain stitch applying 5.0 stitches per cm density. Specimens without and with the seams were conditioned in standard atmosphere conditions according to the standard LST EN ISO 139 before air permeability testing according to the standard LST EN ISO 9237. Standard thickness of the investigated knitted fabric was determined according to the standard EN ISO 5084. It is known from literature that the porosity is dominant factor influencing the air permeability of knitted fabrics. Therefore, the assumption was made that due to fabric porosity knitted fabric thickness being measured at different pressures also may differ. Thus, the permeability property may also be related to the difference between fabric’s thicknesses being measured under different pressures which may be applied with different material thickness gauges. Findings There was shown that fabric assemblies make the significant influence on the textile permeability to air. The results obtained indicate that the air permeability of the investigated knitted fabrics depends not only on their structure parameters but also on the fabric seam type. Air permeability of the specimens with the seams was lower than one of specimens without the seams. The highest decrease in permeability which ranged from 19.9 per cent up to 60.0 per cent was determined for the bonds. Fabric specimens with 607 covering chain stitch seam were in the second place with regard to the previously considered parameter. And, their permeability was decreased from 0.6 per cent up to 52.6 per cent. Changes in the air permeability of the specimens with 512 overedge chain stitch seam were lowest in the range of investigated assemblies. Based on the determined results, it was concluded that the thickness difference of the specimens with and without seams measured at different pressures is related to fabric porosity which makes the significant influence on the air permeability. Practical implications The samples of investigated fabrics were taken from the two companies which manufactures leisure clothing and sportswear such as skiing or swimming costumes, etc. Thus, the obtained investigation results are significant not only for clothing science but also leads the improvement of clothing quality in fashion industry. Originality/value Assuring the comfort of the human body is one of the most important functions of clothing, especially of sportswear and leisure wear. Knitted fabrics should not only be elastic, but also have high air permeability for easily transmit of the perspiration from the skin to the atmosphere, thus making the wearer to feel comfortable. In this research, the air permeability of commercially available polyester knitted fabrics containing different amount of elastane was investigated and the influence of fabric assemblies on the air permeability property was evaluated. A new approach based on the fabric thickness measurement at different pressures and the standard methods for the evaluation of air permeability were used.

Prediction of deformation behavior of single jersey cotton knitted fabrics using finite element method

2014 ◽  
Vol 26 (3) ◽  
pp. 222-234 ◽  
Author(s):  
E. Perumalsamy ◽  
J.C. Sakthivel ◽  
N. Anbumani
Keyword(s):  
Finite Element ◽  
Tensile Test ◽  
Deformation Behavior ◽  
Structural Changes ◽  
Knitted Fabric ◽  
Loop Length ◽  
Loop Model ◽  
Knitted Fabrics ◽  
Content Type ◽  
Single Jersey

Purpose – The purpose of this paper is to elucidate the stress-strain relationships of single-jersey knitted fabrics from uniaxial tensile test followed by deformation behavior using finite element analysis. In order to elaborate the study, high, medium and low tightness knitted fabrics were selected and deformation of fabrics analyzed in course, wales and bias directions (0, 45 and 90 degrees). Design/methodology/approach – This study focussed on uni-axial tensile test of produced test samples using Instron 6021 tester and a development of single-jersey knitted loop model using Auto Desk Inventor software (ADI). The knitted fabric material properties and knitted loop model was imported to ANSYS 12.0 software. Findings – Due to structural changes the tightness and thickness of knitted fabric decreases with increase in loop length The tensile result shows maximum breaking strength at course direction (13.43 kg f/mm2 at 2.7 mm) and maximum extension at wales direction (165.77 kg f/mm2 at 3.3 mm). When the loop length increases, the elongation of fabrics increased and load carrying capacity of fabrics reduced. The Young's modulus, Poisson's ratio and shear modulus of fabrics reduced with increase in loop length. The deformation of fabrics increased with increase in loop length. The increase in loop length gives large amount of structural changes and it is due to slacking or jamming in loops and loosening in dimensions. When comparing the deformation results, the variation within the fabric is higher and structural damage little more when increasing the loop length of the fabric. Originality/value – From ANOVA test, stress and strain distribution was statistically significant among course, wales and bias directions at 95 percent confidence level. The values got from Instron test indicates that testing direction can alter its deformation. In deformation analysis, comparing both experimental and prediction, high amount of structural changes observed in wales direction. The used tetrahedral elements can be used for contact analysis with high accuracy. For non-linear problems, consistent approach was proposed which makes the sense to compare with experimental methods. The proposed model will make possible developments and the preliminary validation tests shows good agreement with experimental data.

Research on mosquito repellent performance of bamboo-polyester blended anti-mosquito yarn seamless knitted fabric

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jingying Xu ◽  
Zimin Jin ◽  
Jing Jin ◽  
Lei Lei ◽  
Jianwei Tao
Keyword(s):  
Environmentally Friendly ◽  
Resistance Rate ◽  
Knitted Fabric ◽  
Mosquito Repellent ◽  
Durability Test ◽  
Knitted Fabrics ◽  
Content Type ◽  
Comprehensive Performance ◽  
The Face ◽  
Life Philosophy

PurposePeople have always been invaded by mosquitoes, and the development of new anti-mosquito fabrics has attracted much attention. The purpose of this paper is to study the effect of knitting process on the performance of anti-mosquito seamless fabrics and provide a basis for obtaining anti-mosquito seamless knitted fabrics with excellent comprehensive performance.Design/methodology/approachThis paper uses bamboo–polyester mosquito repellent yarn containing wormwood extract as the face of seamless knitted fabric. The test factors include ordinary material in the face yarn, ground yarn material, seamless knitted structure and arrangement ratio of ordinary yarn and anti-mosquito yarn in face yarn. According to the quasi-level additional orthogonal test, 12 knitting plans are determined, and the mosquito repellent test and durability test are performed on the fabric.FindingsThe experimental results show that the optimal fabric for anti-mosquito performance is 12#, and the average repellent rate after washing 15 times is 58.57%. The corresponding process is that the face yarn is fully anti-mosquito yarn, the fabric is a single-sided mesh structure and the ground yarn is made of 4.4tex moisture-absorbing nylon/2.2tex spandex wrapped yarn.Research limitations/implicationsIn this paper, there is still a lack of diversity in the selection of yarn materials and fabrics. In the follow-up research, the authors will use more fabrics and yarn materials for combination and experimentation and simulate and predict the mosquito resistance rate of knitted fabrics with different materials and structures.Practical implicationsThe development of anti-mosquito seamless knitted fabrics with good comprehensive performance and the use of environmentally friendly wormwood repellents not only conform to the current people's healthy and environmentally friendly life philosophy, but also promote the development of the functional seamless knitted fabric market.Social implicationsIn addition, seamless knitted fabrics have a huge market prospect, and many of their fabrics are used for sports underwear and outdoor wear. Therefore, the research and development of functional knitted fabrics will attract consumers to buy. While improving the wearing comfort, it can increase profits for the company.Originality/valueThe mosquito-proof functional seamless knitted fabric developed in this research has a high mosquito-proof rate after 15 times and can be used as underwear fabric or outdoor sports fabric.

Research on the surface of multilayer weft knitted fabrics using computer simulation

2015 ◽  
Vol 27 (4) ◽  
pp. 561-572 ◽  
Author(s):  
Lanming Jin ◽  
Gaoming Jiang
Keyword(s):  
Computer Simulation ◽  
Large Scale ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Surface Model ◽  
Knitted Fabric ◽  
Loop Model ◽  
Knitted Fabrics ◽  
Content Type ◽  
3D Effect

Purpose – Multilayer weft knitted fabrics possess many advantages, such as strongly stereoscopic patterns, soft handling and adjustable thickness of apparel and home textiles use. However, it is difficult to predict the final visual effects before the productive process because of the three-dimensional (3D) effect caused by the connecting yarn of the fabric. The purpose of this paper is to realize a realistic simulation of the fabric. Design/methodology/approach – The authors applied to the curve and surface model to simulate the knitted fabric, instead of previous single loop model by NURBS. Macro simulation is more suitable for the fabric with the 3D effect because of the quick, real and convenient simulation. This research includes experiments on the structural parameters concerning the regular sag of multilayer weft knitted fabrics, and analysis of parameter data and the simulation process with the aim of realizing a computer simulation of the fabric, especially with a sense of reality. The Digital Elevation Model was also applied to build a simulated 3D model. Findings – To obtain the values for the change rules, different samples were used and the outputs of the model were found to be close to the experimental results. The thickest and thinnest lengths and the changing curves between them were established. Patterned simple multilayer weft knitted fabric could be simulated through the results of the research. It is possible to simulate different real fabrics using their materials and expected effects. The authors are going to improve the model to simulate the complicate large-scale jacquard fabrics in further research. Practical implications – The results will be useful for establishing a computer surface simulation system for stereo perception of fabrics. Originality/value – The authors put forward the concept of surface warpage degree (R). It is an important factor affecting the fabric stereo feeling. The larger the value of R, the stronger the stereo sense of the fabric. It could be applied to most 3D fabric. A thickness difference testing method was proposed to characterize the stereo perception of fabrics. It is possible to simulate different real fabrics quickly without the model of the woven loop.

The impact of sewing thread's tensile behavior and laundering process on the seam puckering of elastic and normal fabrics

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Reyhaneh Kamali ◽  
Yasaman Mesbah ◽  
Fatemeh Mousazadegan
Keyword(s):  
Woven Fabrics ◽  
Tensile Behavior ◽  
Content Type ◽  
Sewing Thread ◽  
Before And After ◽  
Key Factor ◽  
Thread Tension ◽  
Sewing Threads ◽  
The Impact ◽  
Seam Pucker

PurposeThe aim of the present study is to consider the influence of the tensile behavior of fabric and sewing thread on the seam appearance.Design/methodology/approachIn this study, the formation of seam puckering on two elastic and normal woven fabrics was explored. In order to prepare samples, various sewing threads were applied. Test specimens were sewn under five different thread tension levels. Then the appearance of samples was evaluated subjectively to determine their seam puckering grade before and after the laundering process.FindingsThe obtained outcomes of this study present that although sewing thread tension increment decreases the seam pucker ranking in the similar sewing condition, elastic fabrics have a greater seam pucker grade compared to the normal fabric due to the fabric extension and contraction during sewing and after sewing process, respectively. In addition, the elastic strain of the sewing thread is the key factor that determined sewing thread's tendency to make seam puckering. Moreover, the laundry process due to the relaxation of the sewing thread decreases the seam pucker grade.Originality/valueThe consistency of the tensile property of fabric and sewing thread is a crucial parameter in improving the seam appearance and obtaining a smooth seam.

scholarly journals Stretch properties of elastic knitted fabric with pillar stitch

2018 ◽  
Vol 13 (4) ◽  
pp. 155892501882072 ◽  
Author(s):  
Olena Kyzymchuk ◽  
Liudmyla Melnyk
Keyword(s):  
Test Methods ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
Textile Materials ◽  
Wide Range ◽  
Binder Type ◽  
Knitted Structure ◽  
Warp Knitted Fabric ◽  
Preliminary Tension

Knitted fabrics and products are subjected to a variety of stresses and loads/deformation during their usage. The loads are different by value, by direction, and by duration. The alternations of loading and unloading or resting processes affect the knitted structure and could bring about changes in the linear dimensions of the fabric or result in the deformation of the knitted items and ultimately the loss of product appearance or its functional properties. A wide range of textile materials resistant to multiply loads was produced by using elastomeric yarn that has an elongation of more than 95% and is able to attain full recovery after relaxation due to its chemical composition. This case study examines two existing test methods for evaluating the stretch properties of textile materials produced with the elastomeric yarns with emphasis on warp knitted abdominal binder-type fabrics. It was found that the linear density of the weft in-laying threads and the preliminary tension of the ground yarn which formed pillar stitch affect stretch properties of elastic warp knitted fabric: the full deformation and its constituent parts. The change in the preliminary elongation of the bare spandex in the 210%–270% range does not have a significant effect.

scholarly journals Liquid Moisture Transportation Properties of Functional Underwears: Part 1

2019 ◽  
Vol 19 (2) ◽  
pp. 97-103 ◽  
Author(s):  
Sajid Hussainn ◽  
Viera Glombikova ◽  
Nasrullah Akhtar ◽  
Adnan Mazari ◽  
Tariq Mansoor ◽  
...  
Keyword(s):  
Image Analysis ◽  
Significant Influence ◽  
Absorption Rate ◽  
Fiber Type ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
Moisture Management ◽  
Vertical Wicking ◽  
Cotton Yarns ◽  
Wetting Time

Abstract This study investigates the effect of material composition on moisture management properties. Fiber type has significant influence on the moisture management properties of knitted fabrics. In this article, single jerseys knitted fabric samples with different yarn compositions were prepared. Liquid moisture transportation properties including wetting time, absorption rate, spreading speed, one-way transportation capability, and OMMC were evaluated by Moisture Management Tester (MMT) and vertical wicking was evaluated using thermography system and image analysis. Knitted sample having fine cotton yarns with coolmax and micro denier multifilament polypropylene showed best liquid transportation properties. There is a strong co-relation between OMMC and accumulative oneway transport index with vertical wicking of knitted samples.

scholarly journals Transfer of Plasmid DNA to Clinical Coagulase-Negative Staphylococcal Pathogens by Using a Unique Bacteriophage

2015 ◽  
Vol 81 (7) ◽  
pp. 2481-2488 ◽  
Author(s):  
Volker Winstel ◽  
Petra Kühner ◽  
Bernhard Krismer ◽  
Andreas Peschel ◽  
Holger Rohde
Keyword(s):  
Plasmid Dna ◽  
Genetic Manipulation ◽  
Current Knowledge ◽  
Virulence Determinants ◽  
Coagulase Negative Staphylococci ◽  
Reliable Technique ◽  
Content Type ◽  
Research Activities ◽  
Wide Range ◽  
Genetic Barriers

ABSTRACTGenetic manipulation of emerging bacterial pathogens, such as coagulase-negative staphylococci (CoNS), is a major hurdle in clinical and basic microbiological research. Strong genetic barriers, such as restriction modification systems or clustered regularly interspaced short palindromic repeats (CRISPR), usually interfere with available techniques for DNA transformation and therefore complicate manipulation of CoNS or render it impossible. Thus, current knowledge of pathogenicity and virulence determinants of CoNS is very limited. Here, a rapid, efficient, and highly reliable technique is presented to transfer plasmid DNA essential for genetic engineering to important CoNS pathogens from a uniqueStaphylococcus aureusstrain via a specificS. aureusbacteriophage, Φ187. Even strains refractory to electroporation can be transduced by this technique once donor and recipient strains share similar Φ187 receptor properties. As a proof of principle, this technique was used to delete the alternative transcription factor sigma B (SigB) via allelic replacement in nasal and clinicalStaphylococcus epidermidisisolates at high efficiencies. The described approach will allow the genetic manipulation of a wide range of CoNS pathogens and might inspire research activities to manipulate other important pathogens in a similar fashion.

scholarly journals Use of Proteins Identified through a Functional Genomic Screen To Develop a Protein Subunit Vaccine That Provides Significant Protection against Virulent Streptococcus suis in Pigs

2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Susan L. Brockmeier ◽  
Crystal L. Loving ◽  
Tracy L. Nicholson ◽  
Jinhong Wang ◽  
Sarah E. Peters ◽  
...  
Keyword(s):  
Immune Response ◽  
Vaccine Trial ◽  
Streptococcus Suis ◽  
Protein Subunit ◽  
Content Type ◽  
Degree Of Protection ◽  
Wide Range ◽  
Associated Proteins ◽  
Clinical Protection ◽  
Cellular Immune

ABSTRACT Streptococcus suis is a bacterium that is commonly carried in the respiratory tract and that is also one of the most important invasive pathogens of swine, commonly causing meningitis, arthritis, and septicemia. Due to the existence of many serotypes and a wide range of immune evasion capabilities, efficacious vaccines are not readily available. The selection of S. suis protein candidates for inclusion in a vaccine was accomplished by identifying fitness genes through a functional genomics screen and selecting conserved predicted surface-associated proteins. Five candidate proteins were selected for evaluation in a vaccine trial and administered both intranasally and intramuscularly with one of two different adjuvant formulations. Clinical protection was evaluated by subsequent intranasal challenge with virulent S. suis . While subunit vaccination with the S. suis proteins induced IgG antibodies to each individual protein and a cellular immune response to the pool of proteins and provided substantial protection from challenge with virulent S. suis , the immune response elicited and the degree of protection were dependent on the parenteral adjuvant given. Subunit vaccination induced IgG reactive against different S. suis serotypes, indicating a potential for cross protection.

Comprehensive study on mechanical properties of coated biaxial warp-knitted fabrics

2021 ◽  
pp. 073168442110204
Author(s):  
Bin Yang ◽  
Yingying Shang ◽  
Zeliang Yu ◽  
Minger Wu ◽  
Youji Tao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Failure Modes ◽  
Least Squares Method ◽  
Tensile Tests ◽  
Tensile Creep ◽  
Base Layer ◽  
Sustained Load ◽  
Uniaxial Tensile ◽  
Membrane Structures ◽  
Knitted Fabrics

In recent years, coated fabrics have become the major material used in membrane structures. Due to the special structure of base layer and mechanical properties, coated biaxial warp-knitted fabrics are increasingly applied in pneumatic structures. In this article, the mechanical properties of coated biaxial warp-knitted fabrics are investigated comprehensively. First, off-axial tensile tests are carried out in seven in-plane directions: 0°, 15°, 30°, 45°, 60°, 75°, and 90°. Based on the stress–strain relationship, tensile strengths are obtained and failure modes are studied. The adaptability of Tsai–Hill criterion is analyzed. Then, the uniaxial tensile creep test is performed under 24-h sustained load and the creep elongation is calculated. Besides, tearing strengths in warp and weft directions are obtained by tearing tests. Finally, the biaxial tensile tests under five different load ratios of 1:1, 2:1, 1:2, 1:0, and 0:1 are carried out, and the elastic constants and Poisson’s ratio are calculated using the least squares method based on linear orthotropic assumption. Moreover, biaxial specimens under four load ratios of 3:1, 1:3, 5:1, and 1:5 are further tensile tested to verify the adaptability of linear orthotropic model. These experimental data offer a deeper and comprehensive understanding of mechanical properties of coated biaxial warp-knitted fabrics and could be conveniently adopted in structural design.

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