Analysis of hybrid woven fabrics with shape memory alloys wires embedded

Until recently, Shape Memory Alloys (SMAs) were predominantly developed for applications in the biomedical and engineering industry, and only a limited number of applications in textiles are known. Fabrics made of natural fibres (e. g. cotton, flax and their mixtures) present many advantages, such as wearing comfort, but they are subject to creasing. The aim of this study was to investigate the possibility of compensating for this disadvantage by using SMAs to create aesthetic low crease flax/cotton fabrics. Body Temperature SMAs (BT SMA) that regain their (straight) form when they are subject to human body temperature were used for this purpose. Clothing and bed sheeting are potential applications of these hybrid structures, which become wrinkle-free when they are exposed to the heat of the body, a hair dryer or that generated by an electrical current. The materials selected to achieve this purpose were the following: (1) textile yarns (e. g. single cotton or flax/cotton yarns, two-fold flax yarns and two types of loop fancy yarns) and (2) BT SMA wires of 300 mu m diameter. A power weaving loom and a hand-weaving shuttle loom were used to embed the SMA wires, and four types of hybrid fabrics were produced. The thickness, wrinkle recovery, dimensional stability as well as the cohesion of the SMA wires in the woven fabric were tested. All the tests were performed before and after a washing cycle for both the hybrid and reference fabrics. An increase in thickness was noticed after washing, and the recovery time after crushing varied according to the type of fabric. The slippage of SMA wires from the fabrics was noticed for all the samples, which was dependent on the type of yarns used, their linear density and the weaving process

Modeling reinforcement structures in textile aimed at biomechanical purposes

While sporting, muscles, tendons and the body in general come under extreme loads which may lead to wrong movements and injuries which impact the performance or lead to mandatory rest. As athletes often wear compression garments, we investigate how reinforcement structures such as elastic bands, yarns or fabric strips with a given pretension, or rigid structures can be added to compression garments to prevent incorrect sport movements. This paper discusses how an existing simulation tool (DySiFil) can be adapted to be able to extract supportive forces and pressures and validates the findings for the case of overextension of the fingers and the thumb

From 3D scan to body pressure of compression garments

Human bodies come under loads in sports. For safety or other purposes, athletes wear compression garments to help avoid wrong postures or movement. We assessed anthropometrics of elite rowers, and found significant differences with the general population, indicating compression garments would behave differently for the athletes. By combining 3D scanning technique and FEM modelling software, we were able to predict compression garment performance on part of the athlete bodies . Abaqus Explicit solver was applied to simulate movement of athletes actually putting on a compression garment, and to track stress distribution during the process

An empirical analysis of potential cyclist injuries and cycling outfit comfort

This study investigated the relationship between pain/injury and training characteristics in cyclists. In addition, ergonomic wear comfort of their garments was investigated. A total of 94 complete questionnaire responses were analyzed. The result indicated that lower back pain was the most prevalent injury causing the highest rates of functional damage and medical attention. The injury level of cyclists was affected by the cluster with elite cyclists reporting pain while cycling. Many cyclists were not very satisfied with the comfort level of their current outfit, 39% of respondents were experienced with different discomfort sensations. The most frequent causes of discomfort were thermal and moisture discomfort sensation related to fabric characteristics. Moreover, design and fit of the garment were considered as cause of discomfort next to thermal discomfort sensation. Therefore, it could be concluded that garments that have good ventilation or breathability and very good fit values were preferred by cyclists. Design, limited choice (availability), appearance/look and quality were the main reason for their brand selection preferences

Mathematical model predicting the heat and power dissipated in an electro-conductive contact in a hybrid woven fabric

Electro-conductive (EC) yarns can be woven into a hybrid fabric to enable electrical current to flow through the fabric from one component A to another component B. These hybrid fabrics form the bases of woven e-textiles. However, at the crossing point of an EC yarn in warp and in weft direction, there is a contact resistance and thus generation of heat may occur in this area. Both phenomena are inseparable: if the contact resistance in the EC contact increases, the generated heat will increase as well. Predicting this electrical and thermal behavior of EC contacts in hybrid woven fabrics with stainless steel yarns is possible with a mathematical model based on the behavior of a metal oxide varistor (MOV). This paper will discuss in detail how this can be achieved

Fit evaluation of sportswear for Belgian elite male rowers in static and dynamic rowing postures

The main objective of the SHAPE study was to assess the anthropometry of elite male rowers and develop customized size charts and sportswear with adequate fit in static and dynamic rowing postures. This paper briefly discusses the anthropometry of Belgian elite male rowers and focuses on the fit features of a related unisuit called SHAPE which is compared against a reference (SMARTFIT) with similar materials and design, whereof the garment construction is based on body charts of average Belgian males. Four elite male rowers evaluated both unisuits in garment size 52 and 58. Most of the ten fit features investigated for SHAPE unisuit were allocated average scores between 3 (adequate fit) and 4 (very good fit). In static posture, the overall fit of the SHAPE unisuit was found slightly better than of SMARTFIT unisuit (average score 3.8 and 3.1 respectively). Unlike SMARTFIT, SHAPE unisuit based on rowers body dimensions scored equally well in static and dynamic rowing postures catch and finish and will likely successfully accommodate repetitive sport movements

Results of the SHAPE project

The overall objective of SHAPE project (Adapted Performance Sportswear) is to develop comfortable and well-fitted sportswear for athletes whose body shapes differ from the average population. Body measurements of professional cyclists and rowers were extracted from 3D scans and compared with average Belgian population. Variation of body measurements and skin-sportswear interface pressure upon rowing and cycling postures was additionally investigated. Significant differences were found between rowers and average Belgian males. Rowing and cycling postures had significant influence on most body measurements and pressure. Fit of prototypes developed based on SHAPE-body sizing charts was positively validated by male rowers. Large number of cyclists critically evaluated their present outfit including fit and comfort. Two prototypes were designed according to individual needs of Gsport cyclists and their functionality, comfort and fit were positively evaluated

Lenoweven: opportuniteiten en beperkingen van de naaldlenotechnologie

In het vorig nummer van Unitex werd de technologie van het lenoweven en meer in detail de naaldlenotechnologie uitvoerig beschreven. Daarin werden reeds kort de opportuniteiten en beperkingen van naaldeleno aangehaald. Door de verhoogde weefsnelheid worden meer toepassingsmogelijkheden voor lenoweefsels economisch haalbaar. Weefsels met hogere dichtheden, vooral dan hogere inslagdichtheden worden haalbaar evenals vervangingsweefsels voor open kettingbreisels. Voorbeelden van ontwikkelingen zijn: - weefsels met “engineered” rek-trekdiagram - weefsels met verhoogde dimensionale stabiliteit bij uitrekking - gaasweefsels voor speciale einddoelen - gordijnen en meubelstoffen - vloerbedekking Er blijven desalniettemin nog een aantal beperkingen die de ophang van deze technologie nog afremmen: (a) technologische kinderziekten, (b) beperkte dessineermogelijkheden, (c) een tekort aan wetenschappelijke kennis en praktijkervaring en (d) de nood aan een betrouwbare meetmethode voor de schuifweerstand. De Vakgroep Textiel van de Hogeschool Gent is, in nauwe samenwerking met de collega’s van de Universiteit Gent, jaren terug gestart met het verkennen en onderzoeken van de (naald)lenotechnologie, waarbij nauw werd samengewerkt met lokale wevers en Picanol. In de afgelopen jaren was dit onderzoek zeer intens in het kader van enerzijds een IWTTetraproject met als doel de mogelijkheden van de naaldlenotechnologie dieper te verkennen en anderzijds een HoGent OF-project om na te gaan in hoeverre met deze technologie ook textielvloerbekleding (“Lenotapijt”) kan geproduceerd worden. In dit artikel wordt ingegaan op een aantal resultaten van dit onderzoek

Comparative analysis of thermophysiological comfort-related properties of elastic knitted fabrics for cycling sportswear

This research focused on the investigation of the thermophysiological comfort properties of four selected knitted fabrics of different fiber blend ratios suitable for cycling wear. Comfort-related properties of the fabrics were determined and compared including air permeability, moisture management properties, drying time, thermal conductivity, and water vapor permeability. For those comfort properties of the fabric to be correlated, fabric structural properties, fabric density, fabric weight, and fabric thickness have been considered. Suited fabrics should have good air permeability, thermal conductivity, moisture management properties, and a short drying time. According to the measurement results, the fabric polyamide/elasane (58/42 PA6.6/EL) with good air permeability, thermal conductivity, moisture management properties, and short drying time was more suited for summer cycling clothing. Furthermore, this paper provides a new understanding of considerations that are needed for several end uses involving specific activity levels