Stitch Pattern Research Articles

Excellent thermal, moisture-permeable weft-knitted fabric with core-sheath yarn structure for foot protection in cold environments

In extremely cold environments, maintaining body temperature and reducing heat dissipation is essential for maintaining human health and life safety, but the field of thermal insulation shoe upper fabric has not been deeply studied. In this paper, based on the dual-scale structure of the yarn and shoe upper fabric, a composite yarn with a core-sheath structure is designed, and a using plating stitch pattern weft-knitted whole garment thermal insulation shoe upper fabric with double-layer structure is proposed. By testing the mechanical properties and thermal and moisture performance of the shoe upper fabric and the thermal insulation performance of the whole shoe, the thermal insulation mechanism of the weft-knitted whole garment shoe upper fabric with a double-layer structure and dual-scale structure design was systematically studied. The results show that the shoes made of polyimide/hollow polyester composite yarn with core-sheath structure yarn have good thermal insulation performance. The use of core-sheath yarns can improve the thermal insulation performance of the shoe, and, with the increase of the ratio of core-sheath yarn, the thermal insulation performance of the shoe is better. Starting from the dual-scale shoe fabric structure, this article proposes a novel method for the industrial production of thermal insulation shoe upper fabrics, which is expected to provide guidance for the further development of thermal insulation shoe upper fabric in the future.

Flexural performance and damage mechanisms of stitched composites under different stitch patterns and densities by acoustic emission

The flexural performance of standard composites has been extensively studied; however, the response of stitched composites with different stitch patterns and densities has received little attention and is not well understood. This study systematically explored the flexural performance of stitched composites with different stitch patterns and densities. The stitches weakened the flexural strength while improving the residual strength of the composites, particularly under a high stitch density. In addition, the stitch threads in the longitudinal stitch pattern preferably resisted the deformation of the bottom side of the specimen, showing superior flexural strength compared with the diagonal and transversal stitch patterns. However, the stitch threads in the diagonal and transverse stitch patterns impeded crack propagation and enhanced the residual strength of the composites. In addition, acoustic emission was used to confirm that the acoustic emission signals and the first moment of rapid increase in cumulative acoustic emission energy were detected earlier under a high stitch density, suggesting that the increase in stitch defects promotes damage initiation and severe damage. The durations with high values and a continuous increase in the cumulative acoustic emission energy after brittle failure indicated that the stitched composites experienced non-catastrophic failure.

Modern Electromagnetic-Radiation-Shielding Materials Made Using Different Knitting Techniques.

This paper summarizes the possibility of employing knitted textile barriers as a shield against electromagnetic fields to protect the human body from their negative impact. Ten variants of knitted fabrics made of electrically conductive yarns, steel, and copper wire that differed in stitch pattern, structural parameters, and raw material, were designed, manufactured, and tested. The knitted fabrics produced differed in structural parameters, including course and wale density, surface density, thickness, thread length in the loop, wale and course take-up, volume cover factor, and surface porosity. These parameters were examined in accordance with the research methodology used in knitting. Barrier measurements were taken in the direction of the wales and in the direction of the courses for two frequencies of electromagnetic fields: 2-4 GHz and 4-7 GHz. It was observed that the shielding effectiveness of the manufactured materials depends on the structural parameters of the fabric, the stiches applied, and the type of yarn.

Towards optimization of sports bra strap design: the role of stitch pattern and stitch length (SL) on the properties of seamless knitted fabrics

The purpose of this study was to investigate the effect of SL and stitch patterns on seamless knitted fabric properties as applied to sports bra strap functionality. Different tuck stitch patterns commonly used for seamless knitted activewear, were knitted with a Santoni machine setting for stitch SL = 70. Textile testing was conducted to narrow down the patterns suitable for bra strap. Significant interactions between pattern and SL on thickness, weight, air permeability, elongation, and breaking force were found. The results confirmed some of the existing knowledge about the influence of tuck stitches on the dimensional properties of weft knitted fabrics, such as increasing their density and stability, but also revealed new insights for patterns with more complex tuck stitch repeats when varying SL. Moisture management measurements for various SL values proved to be critical in selecting the best stitch pattern (tuck pattern#10) and SL = 115 that could lead towards optimization of sports bra strap design and highlighted the inconsistent tuck pattern fabric behavior in the presence of moisture.

Self-healing potential of stitched glass/polypropylene/epoxy hybrid composites with various fibers

This study compares the impact damage response and self-healing potential of unstitched and stitched glass/polypropylene (PP) fiber reinforced thermoset composite structures. The novelty of this study is weaving preforms with an intra-ply hybridization of glass and thermoplastic PP fibers and stitching these preforms with a unique stitching pattern by considering the effect of stitching fiber types (PP, Kevlar®, Dyneema®, carbon and silk) on impact damage response and self-healing potential of composites. The mechanical properties of the stitching fiber influenced the composite’s behavior against impact and compressive loads. The unstitched composite deflected more than stitched composites under the same impact energy levels due to delaying of delamination via stitching process. The stitching process reduced the damage areas of composites subjected to 30 J and 60 J impact energies by 57 and 86%, respectively. Structural healing significantly decreased the damaged areas of both unstitched and stitched composite structures up to 87%, while it was more effective on stitched composites. The polypropylene melted and accumulated along the path of the stitch pattern, regardless of whether the stitching fiber was thermoplastic. Due to the reduced impacted area, compression after impact (CAI) strength retention of the stitched composite materials increased by up to 94%.

Programming mechanics in knitted materials, stitch by stitch

Knitting turns yarn, a 1D material, into a 2D fabric that is flexible, durable, and can be patterned to adopt a wide range of 3D geometries. Like other mechanical metamaterials, the elasticity of knitted fabrics is an emergent property of the local stitch topology and pattern that cannot solely be attributed to the yarn itself. Thus, knitting can be viewed as an additive manufacturing technique that allows for stitch-by-stitch programming of elastic properties and has applications in many fields ranging from soft robotics and wearable electronics to engineered tissue and architected materials. However, predicting these mechanical properties based on the stitch type remains elusive. Here we untangle the relationship between changes in stitch topology and emergent elasticity in several types of knitted fabrics. We combine experiment and simulation to construct a constitutive model for the nonlinear bulk response of these fabrics. This model serves as a basis for composite fabrics with bespoke mechanical properties, which crucially do not depend on the constituent yarn.

Influence of stitch type division and geometry on the electrical properties of conductive embroidered structures

Conductive threads are essential for enabling the functionality of e-textiles in sensor applications. However, in this field, there is still a need to study their practical usage, particularly thick embroidered structures. This study investigates the potential of using conductive embroidered structures as sensors and examines how different stitch types can affect the electrical properties of embroidered structures in e-textiles. The paper also explores the application of embroidered structures in twisting and temperature variation, and evaluates their stability when subjected to washing, abrasion and cyclic tension. Three rectangular structures with varying stitch types and geometries were embroidered and tested. The findings highlight the influence of stitch types on electrical properties and demonstrate how washing can affect the different stitch patterns. Furthermore, the structure with the largest jump length can be used in a design suitable for sensing twisting, while all three structures are suitable for detecting temperature variations. This research adds to the development of efficient and long-lasting embroidered electronics textile by providing significant insights for e-textile industrial production.

Influence of carbon fiber non-crimp fabrics stitching parameters on the out-of-plane permeability in liquid composite molding process

The widespread use of carbon-fiber-reinforced plastics (CFRP) has attracted many industries such as defense, and aerospace as well as in sailboats, automotive, and rotor-blades, where high strength-to-weight ratios are required. For the aerospace and defense customer today, the importance is no longer just on minimum weight and therefore performance, but primarily on cost of ownership. Textile-manufactured composites, particularly of non-crimp fabric (NCF) type offer significant cost savings in terms of reduced labor time and higher deposition rates over the unidirectional prepreg tape which is the most traditional method. Vacuum vacuum-assisted infusion method is the most used production technic in CFRP parts which also offers high fiber ratios. The most important goal is the impregnation of carbon fiber package in a through-the-thickness direction to get good quality parts in infusion. The behavior of the impregnability depends mainly on the out-of-plane permeability of the fabric. The fiber type, orientation of the fibers, and the stitching parameters, mainly influence the permeability of the fabric. In this study, the influence of textile parameters on the out-of-plane permeability of UD (unidirectional) carbon fiber NCF was investigated. The stitching yarn parameters (stitch pattern, stitch tension, and stitch length) were varied to see the influence on the out-of-plane permeability. The out-of-plane permeability was measured using a tailored visual flow front monitoring method by measuring resin flow distance on the X and Y axes of the fabric during infusion. The results show that the out-of-plane permeability of the UD (0°) carbon fiber NCF is significantly affected by the stitch pattern, stitch tension, and stitch length.

Warp-knitted fabric structures for a novel biomimetic artificial intervertebral disc for the cervical spine

As an attempt to better replicate the complex kinematics of a natural disc, a novel biomimetic artificial intervertebral disc replacement (bioAID) has been developed containing a swelling hydrogel core as nucleus pulposus, a fiber jacket as annulus fibrosus and metal endplates to connect the device to the adjacent vertebrae. The first prototype consisted of a weft-knitted fiber jacket, in which only a single fiber was used to create the jacket structure. This can endanger the structural integrity of the complete device upon yarn damage. Therefore, in this study, several warp-knitted textile structures were assessed to (1) ensure structural integrity, (2) while allowing for swelling constraint of the hydrogel and (3) behaving as one integrated unit similar to the natural IVD. Moreover, the fiber jacket should (4) act as a scaffold that allows bone ingrowth to ensure long-term stability and (5) have a good durability, (6) be wear resistant and (7) have good manufacturing feasibility with good quality control. In this study, 4 different stitch patterns, including 2 × 1 and 1 × 1 lapping with and without a pillar stitch, were produced. The effect of the stitch pattern and stitch density on the fabric mechanical properties and device swelling and compressive strength was assessed. As a next step, the effect of using multiple layers of fabrics, mimicking the layered structure of annulus fibrosus, on the functional capacity of the bioAID was characterized. All textile structures were capable of limiting the swelling of the hydrogel while withstanding its internal pressure and showing sufficient wear resistance. However, only the 2 × 1 and 2 × 1 with pillar stitch had a pore size range that was suitable for cell infiltration to facilitate osseointegration as well as having the highest strength of the complete device to ensure safety under compression loading. Incorporating different number of jacket layers of these two stitch patterns did not show any significant effect. When also taking the structural parameters into consideration, the 2 × 1 lapping design with 4 layers was able to constrain hydrogel swelling, provide a high compressive strength, could facilitate cell infiltration and had dimensions within the range of a natural intervertebral disc.

Stitched Transmission Line for Broadband Operations

Wearable stitched transmission lines made from stripped RG174 and textile materials are introduced for broadband operations. The stitched transmission lines which are 150 mm long consists of an inner conductor surrounded by a tubular insulating layer. For shielding purposes, the structures are stitched into a denim material with conductive threads. The performances of the stitched transmission lines with three different stitch patterns, Double Overlock, Flatlock stitch and Ric-Rac stitch were investigated and results obtained confirm that Ric-Rac stitched transmission line has fewer DC losses than the three stitched transmission lines for frequencies up to 1 𝐺𝐻𝑧. However, beyond that up to 2.4 𝐺𝐻𝑧 and above, it was observed that the Flatlock stitched transmission line and the Double Overlock stitched transmission line have fewer radiation losses compared to the Ric-Rac stitched transmission line. Similarly, the performance of the stitched transmission line when bent through curved angles of 90° and 180° was considered, and a much better 𝑆ଶଵ was observed with a curved angle of 180° for frequencies below 2.1 𝐺𝐻𝑧, with radiation loss increasing afterwards. Finally, the sensitivity of the design to manufacturing tolerances, with changes in cross-sectional dimensions of the stitched transmission line and the transmission characteristics with different textile substrates were both considered. While simulated results showed that the stitched transmission line is sensitive to small variations in its circular dimensions, measured results conversely showed that Denim and Felt materials can be used as a substrate without any significant effect on its propagation characteristics.

Material characterisation of biaxial glass-fibre non-crimp fabrics as a function of ply orientation, stitch pattern, stitch length and stitch tension

Due to their high density-specific stiffnesses and strength, fibre reinforced plastic (FRP) composites are particularly interesting for mobility and transport applications. Warp-knitted non-crimp fabrics (NCF) are one possible way to produce such FRP composites. They are advantageous because of their low production costs and the ability to tailor the properties of the textile to the reinforcement and drape requirements of the application. Based on their specific production parameters, their draping properties can vary significantly. Draping simulations are used to predict the forming behaviour without relying on costly and time consuming trial and error experiments. However, these simulations require a broad material dataset to make accurate predictions. Previous studies have investigated the relationships between production parameters and drape behaviour only in isolation for a limited number of material parameters at a time. In this study, a comprehensive material characterisation is carried out. The influence of ply orientation, stitch pattern, stitch length and stitch tension on the tensile and bending properties and the friction, shear and drape behaviour of NCFs are investigated on a meso and macro scale. Furthermore, the inter-ply sliding phenomena in bias extension tests are analysed and the results of bias extension and picture frame tests are compared.

XAML Digital Representation of Embroidery Cross Stitch Symbols

This paper studies problems related to the development of craft software. It proposes an approach to developing an application for digital representation of stitches in cross stitch pattern software. The software is oriented to people manufacturing national Bulgarian costumes and clothing employing national Bulgarian cross stitch and embroidery. As UI elements, stitches are represented in XAML code. Graphic primitives are described in vector format; character transformations are allowed, and there are possibilities for creating combinations of stitches. The solution will be used in cross stitch software development.

Topology based modelling of crochet structures

Crocheted textiles receive scarce scientific study and are at present not produced in automatized industrial scale. Computer-aided modelling and simulation offer capabilities for investigating possible technical fields of application. In this context a novel approach for modelling crocheted textiles consisting of chains, slip stitches and single crochets using a topology based and parameterized key point representation at the meso scale is proposed. According to the stitch size, yarn diameter and pattern spline interpolated models, which are free of interpenetrations up to approximately a 1/10 ratio of yarn diameter to stitch size, are generated by a developed Python program and software from the company TexMind. The models are suitable for finite element method (FEM) applications with LS-DYNA with which the mechanical properties of crocheted textiles can be studied. Exemplary simulations show anisotropic properties and homogeneous distribution of stresses in a crocheted textile. Due to the computationally simple and flexible modelling the presented approach may serve as a tool for designing planar crocheted textiles. This allows for estimation of the required yarn length and offers the prediction capabilities of simple and fast FEM simulations based on beam elements.

Study of superhydrophobicity according to surface structure of knitted fabrics

This study seeks to analyze the effect of geometric structures of weft-knitted fabrics on superhydrophobicity and the dynamic behavior of water droplets. A flat knitting machine with different stitch patterns was used to prepare 100% polyester knitted fabrics. For the superhydrophobic surface, nano-roughness through alkaline treatment and a hydrophobic coating were introduced on prepared knitted fabrics. To analyze micro-roughness, pore size, cover factor, surface roughness, and air permeability were measured. Surface wettability was evaluated by contact and shedding angle measurements, and the dynamic behavior of droplets. Micro-roughness was greater in the order of tuck, purl, and plain jersey stitch patterns with a small cover factor and large pore size. In addition, tuck and purl stitches showed differences in surface roughness according to the wale and course directions. Nano-roughness was discernible as the alkaline treatment time increased. Following an evaluation of the wettability, the purl stitches exhibited a contact angle of 150° or more with only the hydrophobic coating. After imparting nano-roughness by alkaline treatment, the contact angle was more than 150° in all the samples. In the case of shedding angle, the tuck and purl stitches showed differences according to the course and wale directions. The shedding angle was lower when the roughness was high and the ridge and the droplet sliding directions were parallel. This difference decreased as the nano-roughness increased according to the alkaline treatment time. An evaluation of the dynamic behavior of water droplets on the superhydrophobic knitted fabric showed that rebound behavior appeared in all the samples on the horizontal surface, when the water droplet was small. However, with large droplets, the rebound behavior appeared only in purl stitches. Meanwhile, on the surface inclined at 15°, rebound behavior was observed in the tuck and purl stitches, with the tuck stitches rebounding faster in the wale direction and the purl stitches in the course direction regardless of the droplet volume. The plain jersey stitches showed pinning behavior after water droplets fell on the surface. Therefore, it is important not only to introduce nano-roughness but also properly to form geometrical micro-roughness of knitted fabric with pores and loops to induce rebound behavior of water droplets.

Loop Order Analysis of Weft-Knitted Textiles

In this paper, we describe algorithms that perform loop order analysis of weft-knitted textiles, which build upon the foundational TopoKnit topological data structure and associated query functions. During knitting, loops of yarn may be overlayed on top of each other and then stitched together with another piece of yarn. Loop order analysis aims to determine the front-to-back ordering of these overlapping loops, given a stitch pattern that defines the knitted fabric. Loop order information is crucial for the simulation of electrical current, water, force, and heat flow within functional fabrics. The new algorithms are based on the assumption that stitch instructions are executed row-by-row and for each row the instructions can be executed in any temporal order. To make our algorithms knitting-machine-independent, loop order analysis utilizes precedence rules that capture the order that stitch commands are executed when a row of yarn loops are being knitted by a two-bed flat weft knitting machine. Basing the algorithms on precedence rules allows them to be modified to adapt to the analysis of fabrics manufactured on a variety of knitting machines that may execute stitch commands in different temporal orders. Additionally, we have developed visualization methods for displaying the loop order information within the context of a TopoKnit yarn topology graph.

Film as Fabric: A visual essay signalling the importance of clothing in expanded cinema performance

In this visual essay, I discuss how clothing made for an expanded cinema performance entitled Film as Fabric took on significance. The live work shows analogue film as fabric and stitching as editing to highlight historical relationships between textile practice and experimental filmmaking. The work developed through iterations from 2013 to 2017 as a part of doctorate research carried out from 2012 to 2020. My position as an experimental filmmaker with a background in embroidery grounded the study. Annabel Nicolson’s seminal live expanded cinema performance Reel Time (1973), in which she punctured 16mm film with her unthreaded sewing machine, was also a point of departure. Feminist critique from both disciplines – film and textile studies – supported the possibility of repressed relationships between the fields. Feminist scholars have repeatedly problematized contextualization of experimental filmmaking as narrow and misplaced (Blaetz 2007; Hatfield 2006; Reynolds 2009, ; ). Until now, connections with textile practice in experimental filmmaking have been largely overlooked, most likely because domestic crafts have a long association with women’s work (), are central to deep rooted Western stereotypes of femininity, and remain denigrated art forms (). The development of Film as Fabric led to the creation of hybrid tools, forms and gestures, such as optical sounds and moving images made from fabric and stitch patterns. These were measured on the body, cut with dressmaking scissors, stitched, spliced into loops and projected in former cotton mills. This process allowed sounds associated with textile production and my personal textile ancestry to re-surface in new ways. The live context demands attention is given to material practices, which typically take place out of sight in the home and the film cutting room and have also recently undergone significant shifts in cultural status.

A mathematical analysis of mosaic knitting: constraints, combinatorics, and colour-swapping symmetries

Mosaic knitting is a method of two-colour knitting that has become popular in recent decades. Our analysis begins with the mathematical rules that govern stitch patterns in mosaic knitting. Through this characterization, we find the total number of mosaic patterns possible in a given size of fabric and bound the number of patterns that are practical to knit. We proceed to a classification of the symmetry types that are compatible with mosaic designs, including theorems that enumerate which one- and two-colour frieze and wallpaper groups are and are not attainable in mosaic knitting. Our discussion includes practical information for knitwear designers and a multitude of sample patterns.

Šivaće mašine ručnih uboda za izradu muških odela

Hand stitches seams along edges of lapels, collars and pocket flaps on a men jacket help to fix canvas interlining under face fabric, keep the edges flat and prevent them from rolling or curling. Traditionally hand stitches seams also indicate high quality of the suit. Real hand stitch machines imitate had stitch 209. Depending on the length of the top and bottom stitch parts the machines can create pick stitches, saddle stitches and other stitch patterns. One group of the machines create stitches by help of a hooked needle, other machines use a double pointed needle. The machines work with limited length threads, most often with 90 cm and 120 cm long ones. The hand stitch seams can to be sewn with special waxed silk threads or regular threads. To increase work productivity and quality the machines use manual or auto thread trimming devices, reverse stitch function, half stitch option, seam beginning and end securing, programmable stitch type, sewing speed, stitch length, thread trimming time.

Computational modeling and data‐driven homogenization of knitted membranes

AbstractKnitting is an effective technique for producing complex three‐dimensional surfaces owing to the inherent flexibility of interlooped yarns and recent advances in manufacturing, providing better control of local stitch patterns. Fully yarn‐level modeling of large‐scale knitted membranes is not feasible. Therefore, we use a two‐scale homogenization approach and model the membrane as a Kirchhoff‐Love shell on the macroscale and as Euler‐Bernoulli rods on the microscale. The governing equations for both the shell and the rod are discretized with cubic B‐spline basis functions. For homogenization, we consider only the in‐plane response of the membrane. The solution of the nonlinear microscale problem requires a significant amount of time due to the large deformations and the enforcement of contact constraints, rendering conventional online computational homogenization approaches infeasible. To sidestep this problem, we use a pretrained statistical Gaussian process regression (GPR) model to map the macroscale deformations to macroscale stresses. During the offline learning phase, the GPR model is trained by solving the microscale problem for a sufficiently rich set of deformation states obtained by either uniform or Sobol sampling. The trained GPR model encodes the nonlinearities and anisotropies present in the microscale and serves as a material model for the membrane response of the macroscale shell. The bending response can be chosen in dependence of the mesh size to penalize the fine out‐of‐plane wrinkling of the membrane. After verifying and validating the different components of the proposed approach, we introduce several examples involving membranes subjected to tension and shear to demonstrate its versatility and good performance.

Macro-Modelling of Rib-Knitted Tubular Parts

The aim of the research was to improve the process of knitted products design. The use of modern software helps us predict the physical and mechanical behaviour of materials, using their three-dimensional models. A macro-model of rib-knitted tubular parts was developed in the study. This model allows its implementation into algorithms, describing the peculiarities of the stretching process. Recent findings in the field of 3D modelling and simulation of knitwear behaviour aim at working with models of different scales of structural hierarchy. The use of macro-models provides the opportunity to simplify the geometry and significantly reduce the time required for simulation. Rib stitch structures are among the most popular weft-knitted ones. When using threads of usual stretchability (with breaking elongation that does not exceed 10–12%), the stretchability of some rib stitch structures in the course-wise direction can reach up to 350% and even more. When stretched in the course direction, rib-knitted stitches undergo a number of stages. The stretching process includes: decreasing the width-wise curling; mutual shifting of knit and purl stitches; reducing the curvature of the loop feet and loop heads; pulling the yarn from the loop legs to the loop feet; stretching of the yarn. The assumption was made that such parts of knitted garments as cuffs and borders on sweaters, cuffs on socks, where rib stitch patterns are used, can be described as thin-walled elastic shells. A part of a human body surface, covered with a rib-knitted garment part, can be approximated by a truncated cone. The mid-surface of the shell can be represented as a ruled surface created upon a set of Bezier curves, located along the circumference of the upper and lower bases of the truncated cone. The mathematical description, elaborated in the course of the research, was used for the computer program LastikTube, which was developed to create 3D macro-models of ribbed tubular garments.