Knitted Structures Research Articles

Analysis of drape co-efficient, bending length, flexural rigidity and tightness factor of 4×1 rib, 4×4 rib, half cardigan and full cardigan knit structure fabric

This study investigates the result of various knit structure on various properties of rib fabric The acrylic yarns were accustomed to make times rib times rib half cardigan and full cardigan structured fabrics using manual V bed knitting machine during this analysis work The consequences of knit structure were measured regarding drape co efficient percentage bending length flexural rigidity and tightness factor The results disclosed that the fabric properties are greatly influenced by knit structures times rib knit structured fabric showed the highest value for all tested properties except drape co efficient and half cardigan knit structured fabric showed the lowest value times rib knit fabric possessed the highest drape co efficient percentage The bending length and flexural rigidity was investigated in both wale and course direction Simultaneously surface and back sides bending length were also calculated From the above mentioned data it rsquo s been known that the effect of knit structure on flexural rigidity in both wale and course direction were influenced in a very same chronological way The highest tightness factor was observed for times rib structured fabric

An experimental investigation of the yarn pull-out behavior of plain weave with leno and knitted insertions

Yarn–yarn sliding force plays a vital role in absorbing impact energy for plain fabrics. This paper reports the methods and results of an investigation on the mechanisms that enable higher yarn pull-out force of woven fabrics with the incorporation of lenos and knits. The experimental results suggested that the insertion of leno lines on plain weave gives an approximately 20% increase in junction rupture force over the original plain construction. With knitted structures inserted, the structure-modified fabrics showed a junction rupture force up to about 15 times higher than simple plain weave. It was even found that the yarns failed rather than pulled out in multiple yarn pull-out tests. This is because knitted structures tend to become self-locked and consequently restrict yarn displacement when subjected to external loading. This investigation reports a method to increase the frictional force between the warp and weft yarns based on textile technologies. It is expected that the results obtained could provide some useful information for the engineering design of flexible ballistic protection systems.

Engineering Graphene Flakes for Wearable Textile Sensors via Highly Scalable and Ultrafast Yarn Dyeing Technique.

Multifunctional wearable e-textiles have been a focus of much attention due to their great potential for healthcare, sportswear, fitness, space, and military applications. Among them, electroconductive textile yarn shows great promise for use as next-generation flexible sensors without compromising the properties and comfort of usual textiles. However, the current manufacturing process of metal-based electroconductive textile yarn is expensive, unscalable, and environmentally unfriendly. Here we report a highly scalable and ultrafast production of graphene-based flexible, washable, and bendable wearable textile sensors. We engineer graphene flakes and their dispersions in order to select the best formulation for wearable textile application. We then use a high-speed yarn dyeing technique to dye (coat) textile yarn with graphene-based inks. Such graphene-based yarns are then integrated into a knitted structure as a flexible sensor and could send data wirelessly to a device via a self-powered RFID or a low-powered Bluetooth. The graphene textile sensor thus produced shows excellent temperature sensitivity, very good washability, and extremely high flexibility. Such a process could potentially be scaled up in a high-speed industrial setup to produce tonnes (∼1000 kg/h) of electroconductive textile yarns for next-generation wearable electronics applications.

Digital interlooping: 3D printing of weft-knitted textile-based tubular structures using selective laser sintering of nylon powder

ABSTRACTThis paper discusses the materialisation of 3D printed textile-based tubular forms that make use of knit’s primary structures. The 3D printed forms explore both single-face and double-face weft knit structures at various sizes. 3D printing is a form of digital additive manufacturing whereby the building up of layers of material creates objects. The selective laser sintering process (SLS) uses a laser beam to sinter powdered material to create objects. This paper builds upon previous research into 3D printed textile-based structures exploring the use of SLS of Nylon powder to create flexible weft knitted structures. The results show the potential to print flexible, tubular textile-based structures at various scales that exhibit the properties of traditional knitted textile structures along with the mechanical properties of the material used to print with. The conclusion highlights the potential future development and application of such pieces within apparel-related industries.

Comparative study of calculated and actual dimensions in shaped weft-knitwear

ABSTRACTThis research explores and quantifies the relationship between traditional mathematical theories used for the calculation of fully-fashioned, weft-knitwear and the physical measurements of knitted garments in order to improve sizing accuracy within knitted garment production. Experiments were conducted to compare and contrast fashioning frequencies for 10-gauge knitted structures, which determined the resultant selvedge dimensions specifically within the armhole region. The trials used the geometrical principle of Pythagoras Theorem to calculate sleeve head and armhole shapes from the stitch densities. The findings identified that the greater distance between the fashionings, the less distortion occurred within the knitted structure and therefore a stronger relationship existed between the calculated seam dimensions and those measured from the physical knitted panels. The research developed new methods for calculating fit and alignment in commercial, fully-fashioned, weft-knitwear. This will result in a more sustainable, fully-fashioned, knitted product and reduce the number of returns to the retailer, due to size inaccuracies.

Effect of Pique and Honeycomb Structures on Moisture Management Properties of Eri Silk Knitted Fabrics

ABSTRACT The present study aims to investigate the moisture management and wicking properties of eri knitted fabrics. In this study, two different knit structures, namely, single pique and honeycomb fabric, were developed with the combinations of two different tightness values of slack and tight by using 2/80s Nm and 2/140s Nm eri silk yarns. The developed fabrics were analyzed for vertical wicking, moisture management properties such as wetting time, spreading speed, absorption rate, maximum wetting radius, accumulative one-way transport index (AOTI), and overall moisture management capacity (OMMC). Variables such as yarn linear density, tightness, and knitting structure have a significant influence on the wicking and moisture management properties. The overall OMMC indices of eri silk knitted fabric lie in the ‘very good’ to ‘excellent’ category, indicating the suitability of eri silk yarn for skin fit as well as active wear applications.

Knittable Stitch Meshes

We introduce knittable stitch meshes for modeling complex 3D knit structures that can be fabricated via knitting. We extend the concept of stitch mesh modeling, which provides a powerful 3D design interface for knit structures but lacks the ability to produce actually knittable models. Knittable stitch meshes ensure that the final model can be knitted. Moreover, they include novel representations for handling important shaping techniques that allow modeling more complex knit structures than prior methods. In particular, we introduce shift paths that connect the yarn for neighboring rows, general solutions for properly connecting pieces of knit fabric with mismatched knitting directions without introducing seams, and a new structure for representing short rows , a shaping technique for knitting that is crucial for creating various 3D forms, within the stitch mesh modeling framework. Our new 3D modeling interface allows for designing knittable structures with complex surface shapes and topologies, and our knittable stitch mesh structure contains all information needed for fabricating these shapes via knitting. Furthermore, we present a scheduling algorithm for providing step-by-step hand knitting instructions to a knitter, so that anyone who knows how to knit can reproduce the complex models that can be designed using our approach. We show a variety of 3D knit shapes and garment examples designed and knitted using our system.

Comfort Properties of Textiles: A Review of Some Breakthroughs in Recent Research

The article critically reviews the recent research trends related to comfort characteristics of fabrics. The comfort properties of fabrics are of sensorial and non sensorial nature. Many researches have focussed on these aspects. Comparative studies on cotton and cotton/polyester blend fabrics woven in various designs have shown that cotton fabrics exhibit better comfort properties than their blend counterpart. Active sports wear is one area where comfort is crucial. In this regard the comfort properties of different bi layered knitted structures made from outer layer comprising of tencel yarn and inner layer of acrylic/microfiber polyester. Such an investigation is intended to largely help the researchers who are analysing the comfort characteristics of layered knitted fabrics for sports wear. Utilization of recycled polyester in the knit apparel industry is ever increasing but the characterization of knit apparel made from recycled polyester yarns is limited to mechanical and moisture management properties.

The characterization of a pressure sensor constructed from a knitted spacer structure

Background and Objectives: This study investigates a novel type of textile pressure sensor fabricated in a single production step. The work characterizes two designs of electronic textile pressure sensor creating new knowledge into the operation of these types of textile sensors. Interest in electronic flexible film and electronic textile pressure sensing has grown in recent years given their potential in medical applications, principally in developing monitoring solutions for wheelchair users and hospital patients to help prevent the formation of pressure ulcers. Materials and Methods: Two designs of textile pressure sensor were produced using computerized flat-bed knitting. One design was produced in a single step, where the conductive tracks were incorporated into the top and bottom surfaces of a knitted spacer structure (knitted spacer pressure sensor). The other sensor was comprised of separate knitted layers. The response of the sensors was tested by changing the applied pressure in two ways: By altering the applied force or changing the area of the applied force. Sensor hysteresis and how the sensor thickness affected its response were also examined. Results: The two sensor designs behaved differently under the tested conditions. The knitted spacer pressure sensor was pressure sensitive up to 25 kPa and showed no hysteretic effects over the pressure range of interest. Conclusions: This study presents a fully textile pressure sensor that was produced with a single production step and demonstrates its functionality over the pressure range of interest for monitoring wheelchair users.

레이저 가공 기법을 활용한 패션 디자인 연구 : 니트 구조를 활용한 원단 개발을 중심으로

레이저 가공 기법을 활용한 패션 디자인 연구 : 니트 구조를 활용한 원단 개발을 중심으로

PREDICTION OF AIR PERMEABILITY OF KNITTED FABRIC BY USING COMPUTATIONAL METHOD

Air permeability is one of the very important factors which need to be considered at the development stage of textile fabrics because it affects the comfort of the clothing. During normal and extreme environmental conditions human body releases heat and the heat can be controlled by the air exchange between the body and clothing microclimate and the external environment; the exchange phenomena depends on the air permeability of the fabric. The air permeability of fabric can be evaluated by both the experimental and computational methods. In this work, a computational method is used for the prediction of air permeability of fabrics. The geometrical model of weft knitted structures was generated by using the actual dimensional parameters of the fabric and was further analysed by applying appropriate boundary conditions. The simulated results obtained from computational analysis were compared to the experimental results. Furthermore, the validated models were further used to predict and analyse the effect of stitch length, stitch density and fibre volume fraction on the air permeability of the fabric.

Inkjet Process for Conductive Patterning on Textiles: Maintaining Inherent Stretchability and Breathability in Knit Structures

AbstractIn this work, a novel technique of inkjet printing e‐textiles with particle free reactive silver inks on knit structures is developed. The inkjet‐printed e‐textiles are highly conductive, with a sheet resistance of 0.09 Ω sq‐1, by means of controlling the number of print passes, annealing process, and textile structures. It is notable that the inkjet process allows textiles to maintain its inherent properties, including stretchability, flexibility, breathability, and fabric hand after printing process. This is achieved by formation of ultrathin silver layers surrounding individual fibers. The silver layers coated on fibers range from 250 nm to 2.5 µm, maintaining the size of interstices and flexibility of fibers. The annealing process, structure of fibers, and printed layers significantly influence the electrical conductivity of the patterned structures on textiles. Outstanding electrical conductivity and durability are demonstrated by optimizing print passes, controlling textile structures, and incorporating an in situ annealing process. The electrical resistance dependence on the strain rate of the textiles is examined, showing the ability to maintain electrical conductivity to retain light‐emitting diode use, stable more than 500 consecutive strain cycles. Most importantly, inkjet‐printed e‐textiles maintain their characteristic washability, breathability, and fabric hands for applications in wearable technology.

Investigating the electromagnetic shielding effectiveness of copper/cotton full Milano and 1 × 1 rib weft-knitted fabrics

In recent decades, the use of conductive textile structures for electromagnetic shielding effectiveness has been increased. In order to reduce, mitigate or completely eliminate destructive and adverse effects of these waves. For this purpose, the Copper/Cotton core spun yarn was manufactured and the copper wires with various diameters (0.06, 0.07, 0.08 mm) as core component were used. Copper/cotton core spun yarns were knitted with two knit structures, Full Milano and 1 × 1 Rib, at machine gauge (8, 10, and 12 per inch). The electromagnetic shielding effectiveness (EMSE) was examined using ASTM D4935-10 standard at frequency range between 0.03 to 1.5 GHz. The results show that heavier and thicker samples with larger stitch density have the higher EMSE values and also Full Milano knit structure with miss stitches provide larger shielding effectiveness values than 1 × 1 Rib knit structures.

Effects of different conductive yarns’ knitting structure on electromagnetic shielding effectiveness

Recently, increasing number of studies are performed on protective fabrics containing conductive yarns for electromagnetic shielding purposes. In this paper, several weft knitted fabrics were developed with conductive yarns of the same yarn count and their conductivity and electromagnetic shielding effectiveness (EMSE) were measured. The variations in EMSE as well as reflection, transmission and other physical properties of knitted conductive fabrics were investigated considering conductive yarns and knit structure. It is observed that an increase in the conductive yarns content significantly alters conductivity while all samples demonstrate sufficient EMSE in high frequency bands; Measurements results are presented herein and future research directions are provided.

Studies on manufacturing of pajamas for patients with extensive burn surfaces

Paper carries out the manufacturing of pajamas made of different knitting structures. One emphasized on criteria necessary to fulfill the medical requirements according with patient critical condition. Considering burns wounds of 3rd degree one has in view the need of thermal insulation (the remaining skin surface does not cover up the ability of thermal insulation and patient is confronted with hypothermia), keeping sepsis condition liquid feeding and a specific pharmacodynamics therapy. The paper has in view two lines one is to obtain a pajamas based on high comfort for hyper sensitized and damaged skin made by means of specific knitting systems and secondly to promote on inner surface of pajamas a specific biomaterial able to speed up healing and fast recovery of burn wound. There presented detailed on progress research obtained on a specific biomaterial and on main lines to obtaining a clothing system able to promote a medical therapy.

On the Thermal and Pressure Characteristics of Sport Compression Garments

In this study, various knitted fabric structures were designed to help preventing muscular difficulties in sports. The samples, containing channels in widthwise direction, were produced by jacquard knitting technique. The effects of channel size and quilted inlay design were investigated in terms of pressure behaviour, thermal and water vapour resistance. Increasing of channel size and adding inlay yarns provided higher thermal resistance, as well as an increase in water vapour resistance, they also significantly affected pressure characteristics of samples.

Evaluating the ultraviolet protection factor (UPF) of various knit fabric structures

Public awareness regarding the risks of prolonged skin exposure to the sun light and more specifically to the UV spectrum part is increased during the last decades. Clothing is the most natural and suitable way of protecting the human body, thus the market interest in clothes that can offer adequate UV protection is growing continuously. Previous research works have revealed the main factors that influence the ability of fabrics to block harmful UV radiation. However, the variability of these factors and the versatility of their combined effect make UV protection factor prediction difficult and hence the design of fabrics with high performance against UV radiation becomes a complicated task. Hopefully, the most critical and predictable among all factors is the fabric structure itself. Expectedly, closer and tighter structures offer higher UV protection. Due to this fact, the majority of previous research concern woven structures which generally are less porous and offer a higher UV protection. However, the possibility to obtain knitted fabrics with adequate UV protection factor is of great interest, since knitted fabrics are more appropriate for sports as well as for casual summer fashion garments. Current literature regarding the UV protection factor of knitted fabrics is very limited and concerns mostly fabrics produced in machines of relative large gauges. In the present work the UV protection factor of various typical weft-knitted structures, produced in a flat knitting machine with 7 gauge and by using grey 100% Organic Cotton yarns, Ne 30/2, 330 TPM (twists per meter) is studied. The yarn has been selected due to the increasing market interest for Organic Cotton products.

High Frequency Attenuation Characterization of Knitted E-Textile Structures

In this research study, knitted fabrics were produced on an E=12 gauge electronic flat bed knitting machine for the High frequency attenuation characterization in the frequency range of 1 GHz -1,5 GhZ. Conductive yarns with different linear resistances were knitted into non-conductive base fabrics made from double covered PA 6.6 core spun lycra yarns. Two different design approaches have been applied for manufacturing of samples. In the first approach, conductive yarn has been knitted in plain arrangement into elastomeric interlock base fabric. In latter case, the base fabric was produced with elastomeric yarns in an interlock arrangement and a conductive yarn was embedded in this substrate to create a series of single loop structures. Effect of design approaches and conductive yarn linear resistance on high frequency attenuation properties of conductive knitted samples was investigated. It was observed while design differences have more effect on attenuation characteristics of samples, linear resistance values of conductive yarns have also slightly affected the properties of samples.

Stretch properties of elastic knitted fabric with pillar stitch

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.

Influence of Knitting Process Parameters on the Thermal Comfort Properties of Eri Silk Knitted Fabrics

Eri silk, a wild silk variety available in the northeastern states of India, has better softness, tensile and thermal properties. The present study aimed to develop different knitted structures and investigate the influence of knitting process variables on the thermal comfort and wicking properties. Knitted single jersey and single pique fabric structures were produced with two sets of yarns – 25 tex and 14.32 tex with three levels of loop length. Thermal properties of the fabric were analysed using an Alambeta instrument, and the wicking ability was measured with an vertical wicking tester. Thermal comfort properties of eri silk were also compared with those of conventional mulberry silk, with the experiment result revealing that eri silk has better comfort values. A statistically significant correlation is found between knitting process parameters viz. the yarn count, loop length knitting structure and the thermal and wickability values of the fabrics.