Knitted Structures Research Articles

Thermal protective performance of single-layer rib-knitted structure and its derivatives under radiant heat flux

The compact construction of fire-resistant woven clothing designed for radiant heat flux protection limits the air permeability from the skin to the environment that risks thermal stress to the wearer. Knitted fabric is well known for its comfort and transmission properties. The inevitable porosity of the knitted fabric has restrained its application in fire-protective clothing. This study attempts to apply tuck and miss elements of a knitted structure to produce a compact yet comfortable flame-retardant fabric with maximum air permeability. The effect of radiant heat exposure at the intensity of 40 kW/m2 and 61 kW/m2 is analyzed for the designed sample. The tuck and miss stitches are used to modify rib-knitted structure and the second-degree burn time estimated using Stoll’s curve. The findings of this research show that a simple modification of rib structure with incorporation of miss stitch can enhance the second-degree burn time to 30 s at the radiant heat exposure of 40 kW/m2.

Abnormal anther development leads to lower spikelet fertility in rice (Oryza sativa L.) under high temperature during the panicle initiation stage

BackgroundDecreased spikelet fertility is often responsible for reduction in grain yield in rice (Oryza sativa L.). In this study, two varieties with different levels of heat tolerance, Liangyoupeijiu (LYPJ, heat susceptible) and Shanyou63 (SY63, heat tolerant) were subjected to two temperature treatments for 28 days during the panicle initiation stage in temperature/relative humidity-controlled greenhouses: high temperature (HT; 37/27 °C; day/night) and control temperature (CK; 31/27 °C; day/night) to investigate changes in anther development under HT during panicle initiation and their relationship with spikelet fertility.ResultsHT significantly decreased the grain yield of LYPJ by decreasing the number of spikelets per panicle and seed setting percentage. In addition, HT produced minor adverse effects in SY63. The decreased spikelet fertility was primarily attributed to decreased pollen viability and anther dehiscence, as well as poor pollen shedding of the anthers of LYPJ under HT. HT resulted in abnormal anther development (fewer vacuolated microspores, un-degraded tapetum, unevenly distributed Ubisch bodies) and malformation of pollen (obscure outline of the pollen exine with a collapsed bacula, disordered tectum, and no nexine of the pollen walls, uneven sporopollenin deposition on the surface of pollen grains) in LYPJ, which may have lowered pollen viability. Additionally, HT produced a compact knitted anther cuticle structure of the epidermis, an un-degraded septum, a thickened anther wall, unevenly distributed Ubisch bodies, and inhibition of the confluent locule, and these malformed structures may be partially responsible for the decreased anther dehiscence rate and reduced pollen shedding of the anthers in LYPJ. In contrast, the anther wall and pollen development of SY63 were not substantially changed under HT.ConclusionsOur results suggest that disturbed anther walls and pollen development are responsible for the reduced spikelet fertility and grain yield of the tested heat susceptible variety, and noninvasive anthers and pollen formation in response to HT were associated with improved heat tolerance.

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

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.

Comparative Analysis on Thermo-physiological Behavior of Eri Silk, Wool and Bamboo Knitted Fabrics Toward Sportswear

ABSTRACT Layered fabrics are utilized for the development of active sport wear applications due to their thermo-physiological properties. In this study, nine different types of knitted fabrics were developed using mill spun yarns of Eri silk, Wool (worsted), and Bamboo with three different knit structures such as single jersey, single pique, and honeycomb. The thermo-physiological properties such as thermal conductivity, thermal resistance, thermal absorptivity, air permeability, and water vapor permeability were studied. Further to this, the moisture management properties such as wetting time, absorption rate, spreading speed, and maximum wet radius of the knitted fabrics were measured. Finally, the overall thermal comfort fabric was compared both subjective and objective manner and found that Eri silk based knitted honeycomb structure was highest rated than other samples.

Predicting Compression Pressure of Knitted Fabric Using a Modified Laplace's Law.

The aim of this study is to develop a mathematical model for the prediction of compression pressure based on fabric parameters, such as engineering stress, engineering strain and engineering modulus of elasticity. Four knitted compression fabrics with different fibrous compositions and knit structures were used. Rectangular-cut strips were employed for the force–elongation characterization of the fabrics. The experimental pressure values between the fabric and rigid cylinder were assessed using a Picopress pressure measuring device. The mechanical and physical parameters of the fabric that influence the interface pressure, such as strain, elasticity modulus/stress and thickness, were determined and integrated into Laplace’s law. A good correlation was observed between the experimental and calculated pressure values for all combinations of fabrics, mounted with variable tension on the cylinder. Over the considered range of pressures, the difference between the two datasets was generally less than 0.5 mmHg. The effect of washing after five, ten and fifteen washing cycles on the fabric–cylinder interface pressure was found to be significant.

Study on Moisture Management Properties of Plated Interlock Knitted Fabrics

ABSTRACT In this study eri silk/micro denier polyester/bamboo, eri silk/micro denier polyester/tencel plated interlock fabrics and the moisture management properties have been developed and analyzed. The effects of raw material combination and fabric structure on moisture management properties with plated interlock knit fabrics are examined. For this study, two types of plated interlock knit structures have been developed. The outer layer made up of bamboo/tencel yarns (14.8 tex), the middle layer micro denier polyester (125 denier) connected with more tuck points, the next to skin layer made up of eri silk yarns (14.3 tex). The result shows that plated interlock knit structure are highly influences the moisture management properties. When compare to eri silk/micro denier polyester/bamboo and tencel combination Excellent moisture management properties were observed in eri silk/micro denier/tencel combination plated interlock knitted fabrics.

Analysis of the stress relaxation of synthetic surgical meshes in view of loading direction

Surgical mesh is a porous fabric, which is used for healing hernia, pelvic organ prolapse, and urinary incontinence. In the present study, synthetic surgical meshes with five different warp knitted structures, including Tricot, Pin hole-net, Sandfly, quasi-Sandfly, and quasi-Marqussite, have been fabricated using polypropylene monofilament, and the effect of loading direction on the stress relaxation of the meshes in orthogonal directions have been considered in comparison with human fascia. The results revealed that loading direction has a significant effect on the stress relaxation of the mesh. Different stress relaxation of various mesh structures in orthogonal directions can be attributed to the pore shape (pore angle) and underlap angle in the structure of the mesh. Except for Pin-hole-net mesh, all mesh structures displayed a constant and independent level of orthotropy to the relaxation time. Moreover, Tricot mesh and quasi-Sandfly mesh, with the level of orthotropy near to1, revealed almost isotropic viscoelastic properties. Overall, the quasi-Marqussite mesh was proposed as the most desirable surgical mesh due to its lighter weight, higher porosity, lower stress relaxation, and closest level of othotropy to the human fascia.

Geometric modeling and recycling of 3D printed fiber reinforced thermoplastic composite plain weft knitted structures

In this paper, a novel geometric model of plain weft knitted structures, considering self-supporting conditions and process requirements is first proposed for 3D printed carbon fiber reinforced nylon composite, where the material extrusion additive manufacturing of a plain weft knitted structure is realized. Next, a recycling process of 3D printed carbon fiber reinforced nylon composite plain weft knitted structures is developed, to obtain recycled filament that can be directly used for 3D printing. The scanning electron microscope micrographs and the interfacial performance of the composite parts, manufactured from the original filament and the recycled one, were compared and analyzed. The results indicate that the performance of the recycled filament is continuously improving, because the recovery process enhances the infiltration of the nylon matrix into the surface of the carbon fiber. In the same printing condition, the tensile strength of composite printed with recycled filament is 56 MPa, which is improved by 16.7% compared to the composite printed using the original filament.

Durable Wash-Resistant Antimicrobial Treatment of Knitted Fabrics

Abstract Antimicrobial finishing is increasingly used in textile products to increase their functionality. Antimicrobial properties became extremely important during the COVID-19 situation. The main problems faced by antimicrobial finishing are nontoxicity and durability (wash-resistance) of antibacterial activity. Also, it is important to determine whether the antimicrobial finishing changes comfort properties, such as air permeability. This paper deals with the durability of antimicrobial treatment, that is, resistance to washing, and effect on the structural changes that may have influence on the comfort properties, such as permeability to air. Knits of various raw compositions were antimicrobial-treated with the new commercial antimicrobial product, Si Bactericidal (Smart Inovation, Portugal). After the antimicrobial treatment, knitted specimens were washed 50 times and changes in their structural parameters, air permeability, and antimicrobial activity were measured. It was found that the mentioned antimicrobial treatment gives very good antimicrobial activity to the treated fabric and is wash-resistant and long-lasting. Also, it does not change dimensions and permeability to air of the treated fabrics with some exceptions of cotton-based knitted structures.

Carbonized Cotton Fabric-Based Flexible Capacitive Pressure Sensor Using a Porous Dielectric Layer with Tilted Air Gaps.

Flexible and wearable pressure sensors have attracted significant attention owing to their roles in healthcare monitoring and human–machine interfaces. In this study, we introduce a wide-range, highly sensitive, stable, reversible, and biocompatible pressure sensor based on a porous Ecoflex with tilted air-gap-structured and carbonized cotton fabric (CCF) electrodes. The knitted structure of electrodes demonstrated the effectiveness of the proposed sensor in enhancing the pressure-sensing performance in comparison to a woven structure due to the inherent properties of naturally generated space. In addition, the presence of tilted air gaps in the porous elastomer provided high deformability, thereby significantly improving the sensor sensitivity compared to other dielectric structures that have no or vertical air gaps. The combination of knitted CCF electrodes and the porous dielectric with tilted air gaps achieved a sensitivity of 24.5 × 10−3 kPa−1 at 100 kPa, along with a wide detection range (1 MPa). It is also noteworthy that this novel method is low-cost, facile, scalable, and ecofriendly. Finally, the proposed sensor integrated into a smart glove detected human motions of grasping water cups, thus demonstrating its potential applications in wearable electronics.

ОСОБЛИВОСТІ 3D МОДЕЛЮВАННЯ СТРУКТУРИ ТРИКОТАЖУ У МАКСИМАЛЬНО РОЗТЯГНУТОМУ СТАНІ

The study aims at the development mathematical basics for software for automated construction of three-dimensional geometric models of knitwear in the most stretched state due to uniaxial stretching along the wale or course direction. Methodology. The research methods of theoretical analysis, spline theory, methods of three-dimensional geometric modeling and parameterization, computer graphics tools, programming tools were used. Findings. During the research, it was assumed that in the maximally stretched state, the tangent to the centerline of the loop at the interlacing point is located at an angle of 45º to the vertical line oriented along the wale direction. Mathematical expressions are proposed for determining the co-ordinates of the characteristic points of the loop in three-dimensional space. An algorithm and its software implementation have been developed as a separate module of the Structure 3D program, designed to create models of knitwear in a stretched state. To verify the algorithm, samples of weft knitted fabrics were made with a 8th gauge flat-bed knitting machine of para-aramid and high-molecular polyethylene threads of linear density 58.8x2 tex and 44x3 tex, respectively. The parameters of the loop structure of the samples in dry-relaxed state and under maximum uniaxial stretching along the wale and the course directions. Tensile testing of specimens was performed on the machine KaoTieh KT-7010AZ. The maximum stress state of the samples was recorded using a Micro Capture Pro microscope to further determine the changes of the loop structure parameters under the action of tensile deformation. The obtained values of the the loop structure parameters of the samples were used as input data for the construction of three-dimensional models. The deviation of the value of the length of the spline representing the centerline of the thread in the loop model from the length of the thread in the loop obtained during the analysis of the samples does not exceed 5%. Scientific novelty. An algorithm for the automated construction of 3D models of knitted structures, undergoing maximum deformations coursed by uniaxial tension along the wales or course directions, has been developed. Practical value. A separate module of the 3D Structure program has been created for the automated construction of a knitted loop undergoing maximal stretching under has been developed.

Moisture management properties of ring vis a vis rotor yarn plated knit structures

The present investigation aims at studying the moisture management properties of polyester-cotton plated fabrics of ring vis a vis rotor yarns. Ring yarn fabrics exhibit higher moisture vapour transmission rate, trans planar wicking, lower wetting time and higher one way transport capacity as compared to rotor yarn fabrics, making the former suitable where body needs to dissipate sweat both in vapour and liquid forms, with respect to fabrics using combination of rotor-spun cotton yarns, which show higher absorbent capacity and would be slow drying with poor one way transport capacity. The study helps us to conclude that yarn spinning system plays an important role in influencing moisture management properties of fabrics intended for next to skin applications.

Moisture Management Properties of Bi-Layer Knitted Fabrics

For investigation of the moisture management properties of bi-layer knitted fabrics, a special knitting structure made of the same or different combinations of yarns of cotton, polypropylene, Microdenier polyester and polyester staple fibre on the face and reverse sides fibre was studied. Moisture management properties, which determine the warm-cool feeling, of the fabrics produced were determined and statistical analysis made. The results indicated that the Microdenier polyester (inner) – Microdenier polyester (outer) fabric had a better moisture management property, providing high levels of comfort, and is recommended for summer, active and sportswear. The results were discussed together with one-way ANOVA test results at a 0.05 significance level. The results indicate that the Microdenier polyester yarn inner and outer layer of bi-layer knitted fabric shows a better moisture management property due to its appreciable wetting radius, as well its good absorption rate, wetting time and spreading speed of sweat, thus exhibiting a very higher level of the comfort property.

Evaluation of Moisture Management Properties of Plated Interlock, Mini Flat Back Rib and Flat Back Rib Structures

Moisture management is a very fundamental criterion for any type of fabric. Hence, in this study three different knits viz plated interlock, mini flat back rib and flat back rib fabric structures with 100% eri silk (top), 100% bamboo (bottom) and 100% tencel (bottom) with the combination of two different yarn counts were used. The yield was tested for moisture management properties. It was identified that the bi-layer eri silk (14.3 tex) combined with bamboo (14.8 tex) and tencel (14.8 tex) plated interlock, mini flat back rib and flat back rib knit structure fabrics were excellent. Due to the high level of comfort and breathable nature, eri silk with bamboo and tencel fabrics are recommended for performance based garments.

Geometry of compact plain knitted structures

Purpose The purpose of this paper is to develop mathematical relationships to calculate the loop length to knit compact plain knitted fabrics and to validate the model using the fabric parameters of commercial fabrics. Design/methodology/approach Ellipse defines the shape of the head of a knitted loop and straight lines define the arms of a knitted loop. The mathematical relationships developed relate the yarn count to the loop length of compact knitted fabrics. The experimental data and the data from previous similar research validate the accuracy of the mathematical model. Findings The model can calculate loop lengths to knit compact plain knitted fabrics in terms of thickness of the yarn and the coefficient defined to express the ratio of minor axis to major axis of the ellipse that defines the shape of the head of the loop. The mathematical model can deliver several loop lengths to produce compact plain knitted fabrics for different values of this coefficient. For commercial fabrics the error of the model was 0.53%. Originality/value The present model defines the head of the loop as an ellipse. The uniqueness of the present model is that several ellipses can exist for any given yarn thickness for a range of values assigned to the minor axis of the ellipse. The accuracy of the model against experimental data ascertains that the model is closer to the reality for commercial fabrics and proves the uniqueness of the model. Further, this model is an ideal and a simple model to introduce knitted loop configurations in teaching knitted fabric geometry.

Development of a three dimensional (3D) knitted scaffold for myocardial tissue engineering. Part I: mechanical performance of the knitted structures

The aim of this study was to design a knitted scaffold for myocardial tissue engineering applications. The textile structure of pile loop knit fabric (terry fabric) was selected as a three dimensional (3 D) scaffold. The candidate fabrics were knitted from textured polyethylene terephthalate (PET) yarns. Biocompatible porous structures were obtained and the mechanical properties of the fabrics were analyzed. The values of the stiffness (Young’s modulus) of the structures were observed to range from 124.09 to 167.01 kPa in the direction of wales, and from 40.16 to 85.28 kPa in the direction of courses at 20% strain, which can be stated not to be far from those reported for the human myocardium. Furthermore, the knit structures were observed to have a pore network mainly consisting of macropores of 100 − 400 µm that were well interconnected with micropores (<60 µm). In this respect, the developed scaffolds could potentially be used as biocompatible materials for the applications of tissue engineering and regenerative medicine.

Development of Cylindrical Filters Used in Conventional Cotton Opening Lines.(Dept.T)

In this research an attempt has been made to modify the construction of a number of circular – knitted structures i.e. interlock, pile fabrics and single pique. This modification could be achieved by means of knowing the optimum constructional factors of each knitted structure such as polyester/cotton blend ratio, tightness factor and yarn twist multiplier. This research is concerned with the development and evaluation of the selected knitted structures for mechanical and dust – filtration applications with regard to specific work of rupture, busting pressure, rate of abrasion, filtration efficiency (7), pressure drop (AP), filter performance ((ϫ, filter efficiency per unit mass (7/M), specific cake resistance (K) and dust emission or out let concentration (Co). The mechanical and filtration properties of these structures are studied and compared with those of similar woven filter fabrics. Mathematical models describing these properties could be obtained, by using factorial design method, for predicting the knitted filter performance. By using the mathematical methods, it was found that the optimum fabric construction is recommended to be contained 100% crimped polyester fibers yarn,17.47 tightness factor (i.e. yarn count 20 Ne, loop length 0.31 cm) and 3αe twist multiplier with using interlock structure (Sample 2A) in the actual operating conditions were more efficient than conventional woven filters.

Development of a three dimensional (3D) knitted scaffold for myocardial tissue engineering. Part II: biological performance of the knitted scaffolds

Cardiac patch has been proposed as an alternative therapeutic tissue engineering strategy to treat damaged heart for patients who survive the acute myocardial infarction (MI). To that end, studies have focused on designing an ideal cardiac patch assisting myocardium to repair itself. The engineering of three dimensional (3 D) anisotropic knitted scaffolds could be an efficient and effective strategy for cardiac patches. Thus, the polyethylene terephthalate (PET) pile loop knit fabrics were fabricated as 3 D scaffolds, where the values of stiffness (Young’s modulus) of the scaffolds were similar to those reported for the human myocardium. Anisotropic porous knitted scaffolds supported the adhesion and proliferation of murine C2C12 myoblasts cell line in vitro. Scaffolds with a high surface to volume ratio and porosity exhibited superior performance in terms of cell adhesion and proliferation. Furthermore, out of thirteen proinflammatory cytokines, the levels of three cytokines including IL-1α, IL-1β, and IL-11 were observed to be higher in cells seeded on scaffolds coated with fibronectin than those in related control groups. Thus, the proposed knitted structure can potentially be used for tissue engineering and regenerative medicine.

Ukrainian Folk Ornaments in Modern Knitting

National arts and crafts are not only the skills of an individual nation but an ethnic phenomenon that has unique features and serves as a source of information on national history and culture. Decorative and applied art in Ukraine combines the traditions and techniques of manufacturing and decoration, which have been developed and passed down from generation to generation. It has a clear national identity and numerous regional differences in ornamental motifs, compositions and favourite colours. Therefore, the Ukrainian folk art has a significant potential and is a source of ideas in creating modern clothing as well as interior items. Embroidery as a way of creating ornamental motifs on a textile material using various techniques is a common process for decorating clothes and interiors for the Ukrainians. Today, ornamental compositions of embroidered folk textiles could be transmitted into modern clothes using various technologies. However, the use of a knitting machine allows creating a pattern during the item production. The ornament transformation into a pattern for knitting can be carried out with graphic software by creating a grid with a cell size similar to the loop size of a knitted structure for corresponding interlooping. A number of clothing and interior items with ethnic motifs was created using the capabilities of flat knitting machines within the masters programme “Knitting Technology and Design” at the Textile Technology and Design Department of the Kyiv National University of Technologies and Design.

Optimum Constructional Factors of Dust Knitted Filter Fabrics.(Dept.T)

In this research an attempt has been made to modify the construction of a number of circular knitted structures i.e. single jersey, interlock, pile fabrics and single pique - This modification could be achieved by means of knowing the optimum constructional factors of each knitted structure such as type of fibres, tightness factor and yarn twist multiplier. This research is concerned with the evaluation of the selected knitted structures for mechanical and dust filtration applications with regard to specific work of rupure, bursting pressure, rate of abrasion, lateral expansion, filtration efficiency, p ressure drop, air resistance and eqivalent pore diameter. Mathematical models describing these properties could be obtained, by using factorial design method, for predicting the knitted filter performance. By using the mathematical methods, it was found that the optimum fabric construction is recommended to be interlock contained 100% crimped polyester fibres yarn, 16.98 tightness factor (i.e. yam count 20 Ne, loop length 0.31 cm, courses per inch 43.5 and 3.25 &e twist multiplier).