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Nowadays, soft avatars are used in various fields to simulate the behavior of human soft tissues in different applications. Likewise, they are also utilized in the garment industry in order to achieve a realistic testing of the fit and functionality of tight-fitting clothing. Therefore it is important that avatars in CAD programs for clothing conform to the mechanical properties of human soft tissue. The accuracy of the avatars' properties in simulating the change in shape of human tissue is crucial here, which is caused by the contact pressure that compressive or tight-fitting garments exert onto the body. In this study, Browzwear’s VStitcher soft avatar Sofia was investigated and different body shapes resulting from being influenced by a legging with different levels of negative ease values were compared with non-affected natural avatar body shape. The examination of the soft avatar simulation shows that although a fast estimation of the tissue displacement can be predicted, there are some shape changes limitations compared to the natural behavior of human soft tissue.

This communication is an overview of the results of the IGF research project 21622 BR Development of novel, stab-resistant protective clothing using continuous fiber-reinforced additive manufacturing. The individual steps of the processing and the further publications are summarized.

Autohesion is a unique class of adhesion that enables the bonding of two identical surfaces by establishing intimate contact at interfaces. Creating intimacy between two identical surfaces poses a challenging task, often constrained by the presence of surface roughness and chemical heterogeneity. To surmount this challenge, we document a variety of autohesive traits in polypropylene-based meltblown nonwovens, accomplished through a facile, scalable, energy-efficient, and cost-effective ultrasonic bonding process. The mean work of autohesion for a single polypropylene bond, serving as a figure of merit, has been computed by extending the classical Johnson−Kendall−Roberts (JKR) theory by factoring in peel strength along with key fiber and structural parameters of nonwoven materials. Achieving a high figure of merit in ultrasonically bonded nonwovens hinges on the synergistic interplay of key process parameters, including static force, power, and welding speed, with the fiber and structural properties acting in concert. In this regard, peel-off force analysis has also been conducted on a series of twenty-seven ultrasonically bonded meltblown nonwovens prepared using a 33 full factorial design by systematically varying process parameters (static force, power, and welding speed) across three levels and extension rate. X-ray microcomputed tomography (microCT) analysis has been performed on select ultrasonically bonded nonwoven samples to discern their bulk characteristics. A broad spectrum of mean work of autohesion for a single polypropylene bond, ranging from 1.88 to 9.93 J/m², has been ascertained by modulating key process parameters.

Ultrasonic welding is an efficient method of joining thermoplastic fabrics or other textile semi-finished products in a watertight manner. It is applied in the making of functional clothing, such as chemical protective clothing, sportswear or smart clothing, or other technical products. Another special field of application developed at the Chair of Development and Assembly of Textile Products is the use of coated textiles as temperature control elements. For this type of product, it is necessary to design the ultrasonic welds in such a way that the media-tight coating is not damaged and the joint is continuous. This paper presents the option of evaluating and optimizing the ultrasonic welding process for the production of the textile tempering systems using transient thermal analysis in order to improve the overall quality of the seam and ensure media tightness along the seam. In the following article, the status of the welding process, in particular the ultrasonic process, the textile materials, the heating of the textile and the joining process of welding is presented. In addition, the transient heat flow through the textile is investigated with the aid of FEM methods; taking into account, various seam structures.

In this study, protective clothing for firefighters is analyzed using 4D body scanning and 3D hand scanning, with a focus on the experimental analysis of ergonomic comfort. In particular, German firefighting clothing is examined to discuss the possibilities and limitations of current scanning technologies for capturing firefighting clothing. For this purpose, various movements are recorded in the 4D scanner. In addition, a method for determining position changes of protective clothing at identified limits is presented. The initial results illustrated that the analysis of protective clothing for firefighters using 4D scanning is problematic due to specific materials, reflections, and surface properties. Improvements in the scanning process and optimization of algorithms are required to achieve more detailed and precise results. Concerning the ergonomic comfort related to the mobility under firefighting clothing use conditions, this methodical case study highlights the limits of current approaches, with a focus on the limitations of 4D scanning and potential improvements.

In the context of developing a machine to automatically crochet fabrics, a suitable design tool tailored to the new technology and enabling its application is crucial. The paper offers first insights into the prototype of the crochet machine and presents the approach of such a design tool implemented in Python for creating, modeling and generating the machine instructions. With a graphical user interface (GUI), a flat crocheted fabric can be designed by arranging international crochet symbols for slip stitch (SL), single crochet (SC) and half double crochet (HDC). Built-in error checking mechanisms, following the rules of crochet and the machine’s constraints, will aid inexperienced crocheters in this process. Based on the resulting computer representation as an array containing short strings for the respective stitches, a topology-based 3D model at the meso scale is automatically created as a preview of the designed crocheted fabric. Also, machine instructions to automatically crochet the fabric with the crochet machine prototype are generated by mapping the computer representation of the stitches to macros of G-code and appending them in a valid order. The straightforward design tool shows the capabilities of the crochet machine and is extensible for further enhancements. Through modeling, the structure of the machine-crocheted fabrics is presented for the first time. In comparison to manually crocheted fabrics, the machine-crocheted ones exhibit a technical front and back, since stitches are formed by the machine only from one side.

The high speed (4D) body scanning provides technical possibility for accurate measurements of the body geometry and can be applied not only for moving objects, but as well for evaluating the changes of static geometry with time. This information is important for compression socks, because it provides data regarding the relaxation processes of the textile product and of the human leg. In this work, changes of the body geometry after 1 and 4 hours with compression socks are investigated. Up to 9% changes of the cross section areas and up to 5.5% of changes of the circumference between the position at the starting point and after 4 hours are detected. Additionally the differences between the both legs of the investigated person and of the different (upper- and bottom) part of the leg are observed. It is the first step to the digitalization of the personal compression stocking design.

When the human body moves, the body curvatures always change on the corresponding parts of the body. For ideal protective clothing, body curvatures during different movements have to be taken into account, as they influence the protection and the wearing comfort. For this reason, this study will focus on demonstrating methods to visually display such curvature changes. The changes are visually shown in different poses. The aim is to use this method to optimize protective elements on body parts with increased curvature changes. This would make protective clothing safer and more comfortable to wear.

Ultrasonic welding is a fast and efficient solid-state welding process widely used in various industries. This study focuses on optimizing seam quality and peel strength in multi-layered hybrid textile materials using continuous ultrasonic welding. The influence of welding process parameters (pressure force, power, and speed) on multi-layered peel strength is examined. Three-by-three experimental designs for two and three-layer weld seams with 6 and 12 mm welding widths were developed and applied using superimposed seam type. The impact of varied factors on multi-layered peel strength was analyzed statistically and explored their corresponding tendencies in the relationships. Numerical optimization and analytical models were used to determine parametric levels for achieving desired peel strength. The results show that peel strength is affected by welding parameters, with variations observed based on layer, width, and speed. Increasing speed reduces peel strength, while higher power and pressure force enhance peel strength up to a certain point. However, excessive power and pressure forces can cause material deformation and reduce peel strength. The study also found a strong correlation between power and peel strength, emphasizing the importance of energy input during welding. Power and speed are identified as significant determinants of peel strength, with their combined influence playing a crucial role. The optimal peel strength (34.86 N/12 mm) is achieved at a welding speed of 2.11 m/min, power of 118.18 W, and pressure force of 343.94 N for a three-layer weld seam with a 12 mm welding width. Nonlinear quadratic analytical models are developed to predict multi-layered peel strength, and their results align closely with the actual points. Overall, this research provides valuable insights into optimizing seam quality and peel strength for multi-layered hybrid textile materials, benefiting weather protection applications and advancing bonding techniques in ultrasonic welding.

The automation of current crocheting technology offers many possibilities. To fully exploit this potential, it is necessary to develop not only hardware, but also methods that enable the design of novel machine-crocheted fabrics. In the case of manual crocheting, approaches for an automated generation of crochet patterns according to 3D shapes have already been presented in the literature. However, the most technically advanced crocheting machine prototype currently proposed automates the crocheting of flat fabrics starting from a chain row. Given the limitations and operation of this so-called CroMat crocheting machine, a tool for shaping flat machine-crocheted fabrics according to 2D convex polygons is presented here. With this, surfaces can be divided into crochet stitches using a tessellation process and numerical optimization. The rules of the automated crocheting process were thus followed to ensure the machine manufacturability of generated patterns. Computer models of the fabrics were used as previews. In addition, the shaping possibilities of the CroMat crocheting machine, in particular with respect to increase and decrease stitches, are presented and discussed by means of the tessellation optimization of exemplary polygon shapes. Generally speaking, the algorithm extends the toolbox for designing machine-crocheted fabrics through the automated generation of valid crochet patterns corresponding to input shapes and according to the possibilities of the CroMat crocheting machine prototype.

To simulate a warp-knitted product with a specific shape, a mesh-based model for modeling and simulation is proposed. The three-dimensional geometry of the final fabric is represented as a set of polygons, each of them containing information about the 3D orientation of the yarns in the warp knitted structure. Using spatial mapping, stitch coordinates are transformed from the flat mesh model to the three-dimensional mesh model and the final rendering is accomplished. The method provides yarn level data for the complete structure and can be used for speeding up the design process of clothing with warp-knitted products. Several challenges with the larger data amount and possible ways for their solutions are discussed.

For a holistic assessment of the interaction between the human body and tight fitted clothing, it is necessary to consider the mechanical properties of the body. Default avatars in CAD software are usually solid and do not take this interaction into account. For this purpose, a solid avatar is converted to a deformable one by using the soft body physics implementation in the simulation program Blender. The fit of a 3D garment on both avatars are compared, which allows a first evaluation of the differences between these approaches.

This paper presents preliminary experimental results on the influence on the aerodynamic drag of a cylinder from the cylinder type (i.e., rigid or soft) and its textile surface. Both a rigid cylinder and a soft-body cylinder, with a gelatin layer, each with five different textile surfaces were measured in the wind tunnel using force measurement technology. The drag coefficient was determined for several Reynolds numbers. The study shows that the elasticity of a cylinder has a significant influence on the drag force and the airflow type. However, the influence of the soft-body cylinder depends on the respective fabric. With the given measurements, no exact statements can yet be made to quantify the influence. This influence must be studied independently and in conjunction with the textile surface in order to gain understanding of the overall system of airflow, textile and elastic body.

This paper examines the influence of different fabric types and material properties on the visual appearance of three types of skirt styles using numerical simulation. The purpose of the simulation is to present and analyze the appearance of virtual garments, create the best-fitting pattern pieces, and choose the appropriate fabric type based on the multiple clothing styles to achieve the intended design. The results show that when the type of fabric changes without changing the clothing style and on the other hand the style changes without changing the type of material, the appearance of the garment changes and the effect can be clearly seen with the 3d comparison result. These changes should be taken into account when choosing the right fabric for different styles.

This paper presents one efficient and accurate EMI shielding performance simulation method for metal particles coated on nonwoven textile-based material with the optimized textile module using the finite element method (FEM) simulated in the waveguide model. Copper particles coated polyester nonwoven materials with three contents of copper were made by the electroless plating method, which was used to evaluate the results from the EMI shielding test and simulation run. The mean absolute percentage error (MAPE) and p-value from the two samples' t-tests show that the simulation results of the two samples are less than 6.08%, and the p-value is more than 0.05. For the rest of one sample, the error of simulated value to measured value is higher (

The Covid-19 pandemic has had a major impact on higher education across the world. In this paper we consider how textile education has been impacted and what approaches have been employed to maintain quality education and laboratory experience when traditional methods are not appropriate. This paper considers three different countries – United States, South Africa and Germany. Each has been affected in a different way, has a different sociological makeup, and has developed distinct solutions to the challenge. Methods related to HyFlex, flipped classrooms, and blending learning have been applied by all three institutions. Lectures have been presented as pre-recorded videos, synchronous video conferencing, and hybrid. Similarly, laboratory and studio experiences have been handled through pre-recorded video, guided “at home” experiments, and modified in-person experiences. This paper gives an overview of the laboratory and studio experiences, time spent in preparation, and reaction of the students to remedies. It also addresses best practices from each country in the three continents.

The purpose of this study is to investigate pregnant women’s maternity dress in relation to their body image at each stage of pregnancy. Firstly, in order to create pregnant body Blender software is used. Then Lectra ModarisV8R2 allows to create a pattern. Finally, Lectra 3D Fit simulate and visualize projects. The paper explains, how to gain pregnant body in Blender and how to prepare a project for visualization in Lectra. The result is pregnancy dress project in 4 sizes and tailored to each stage of pregnancy.

The application of additive manufacturing, well known as 3D printing, in textile industry is not more totally new. It allows is giving significant increase of the product variety, production stages reduction, widens the application areas of textiles, customization of design and properties of products according to the type of applications requirement. This paper presents a review of the current state-of-the-art, related to complete process of additive manufacturing. Beginning with the design tools, the classical machinery building computer-aided design (CAD) software, the novel non-uniform rational B-spline (NURBS) based software and parametric created models are reported. Short overview of the materials demonstrates that in this area few thermoplastic materials become standards and currently a lot of research for the application of new materials is going. Three types of 3D printing, depending on the relation to textiles, are identified and reported from the literature—3D printing on textiles, 3D printing of flexible structures and 3D printing with flexible materials. Several applications with all these methods are reported and finally the main advantages and disadvantages of the 3D printing in relation to textile industry are given.

Měření tepelné vodivosti textilních struktur pro oblečení je stále velkou výzvou. Důvodem je, že tyto hodnoty jsou na hranici spodního rozsahu stávajícího vybavení současných zkušebních zařízení, nebo i nižší. Na druhé straně je ale vyžadována optimalizace tepelného komfortu oděvů. Pánské i dámské oděvy jsou vytvářeny z několika vrstev, a pouze s kompletními informacemi o každé vrstvě jsou možné složitější výpočty a kalkulace. Tato práce prezentuje část rozsáhlejších experimentálních studií, týkajících se Rct hodnot tkaných a pletených struktur sestávajících z několika vrstev. Byla změřena stlačitelnost a tloušťka jednotlivých vrstev i vícevrstvých struktur. V obou případech byla použita standardní testovací zařízení a provedena analýza příčného řezu vrstev zalitých do pryskyřice. Za účelem zkoumání vlivu vzduchu mezi několika vrstvami byly Rct hodnoty pěti vrstev se stejnou strukturou odhadnuty pomocí zařízení PERMETEST společnosti Sensora. Byly zjištěny a statisticky prokázány jisté korelace mezi hodnotami Rct, počtem vrstev a objemem vzduchové vrstvy mezi jednotlivými vrstvami. Různé kombinace vrstev materiálů používaných na běžné ošacení, od spodního prádla po vrchní vrstvy oděvů, byly experimentálně analyzovány a porovnány s teoreticky vypočtenými hodnotami.

The yarn level modelling of warp knitted structures is a complex process. For structures placed on the plane, it is well investigated and there are a few software solutions and papers reported. This paper considers the simulation of warp knitted structure, deformed in the 3D space. Especially the modelling of the areas of high curvature are detailed observed. Underlaps with longer lengths makes an unreal visualization for simulation results. Different pattern with different length of the underlaps are modelled with original algorithm developed by the authors. Modelling and visualization problems in the areas with long underlaps are discussed and possible solutions are proposed. [ABSTRACT FROM AUTHOR]