The Dimensional Properties of Single-Jersey Loop-Pile Fabrics. Part II: Studies of Fabrics With Textured Continuous-filament Yarns in the Ground Structure

Studies of the dimensional properties of single-jersey loop-pile fabrics produced from cotton pile and textured polyamide- and polyester-fibre ground yarns are reported. The model proposed for flat continuous-filament ground-yarn fabrics also applies to these structures. It is shown that the fully relaxed dimensions of fabrics produced with textured ground yarn are controlled by the stitch length as well as the bulking potential of the ground yarn.     

A study on thermal properties of single-jersey knitted fabrics produced from ring and compact folded yarns

This paper presents a study on the thermal properties of single-jersey knitted fabrics manufactured using ring, compact and ring/compact folded yarns. The variations in thermal properties depending on the yarn twist and traveller weight of folded yarn single-jersey knits were discussed. It was found that the thermal resistance of knitted fabrics generally increases as the traveller weight decreases, and also water vapour permeability reduces as the traveller weight decreases. The water vapour permeability and air permeability of knitted fabrics increase as the twist increases. The thermal conductivity of knitted fabrics decreases as the twist increases. The air permeability and water vapour permeability values were higher for compact folded yarn fabrics as compared to those values of ring and ring/compact folded yarn fabrics. It is observed that yarn twist and traveller weight have affected different thermal properties of single-jersey folded yarn fabrics.     

The Dimensional Properties of Single-Jersey Loop-Pile Fabrics. Part I: Studies of Fabrics with Flat Continuous-filament Yarns Used in the Ground Structure

This paper is concerned with a detailed study of the main factors that determine the geometry and dimensional properties of single-jersey loop-pile (full-plush) fabrics. It covers the parameters of material, machine, and fabric. It is established that the linear as well as the area dimensions of single-jersey loop-pile fabrics are largely controlled by the Stitch length knitted into the ground structure and the state of relaxation in which the dimensions are measured. An empirical model for predicting stitch length in dry- and fully-relaxed fabrics is suggested.     

20—THE INFLUENCE OF SOME PRODUCTION PARAMETERS ON THE CHARACTERISTICS OF NEEDLEFELTS FOR GAS FILTRATION

An investigation is described in which needlefelt fabrics were designed and constructed. The effect of fibre fineness on filtration characteristics is demonstrated.     

Comparison of compression properties of stretchable knitted fabrics and bi-stretch woven fabrics for compression garments

Stretchable fabrics have diverse applications ranging from casual apparel to performance sportswear and compression therapy. Compression therapy is the universally accepted treatment for the management of hypertrophic scarring after severe burns. Mostly stretchable knitted fabrics are used in compression therapy; but in the recent past, some studies have also been found on bi-stretch woven fabrics being used as compression garments as they also have been found quite effective in the treatment of edema. Therefore, the objective of the present study is to compare the compression properties of stretchable knitted and bi-stretch woven fabrics for compression garments. For this purpose, four woven structures and four knitted structures were produced having same areal density and their compression, comfort and mechanical properties were compared before and after 5, 10 and 15 washes. The four knitted structures used were single jersey, single locaste, plain pique and honeycomb, whereas the four woven structures produced were 1/1 plain, 2/1 twill, 3/1 twill and 4/1 twill. The compression properties of the produced samples were tested by using kikuhime pressure sensor and it was found that bi-stretch woven fabrics possessed better compression properties before and after washes and retain their durability after repeated use, whereas knitted stretchable fabrics lost their compression ability after repeated use and the required sub-garment pressure of the knitted structures after 15 washes was almost half that of woven bi-stretch fabrics.     

Pulsed forward flushes as a novel method for cleaning spent grains-loaded filter cloth

This paper presents a novel method to remove spent grains efficiently from filter cloths via pulsed forward flushes. In breweries, mash filters separate liquid wort from solid spent grains, a by-product. These mash filters use woven fabrics made from synthetic materials as filter media. However, rough filter surfaces often hinder the cleaning process. Concerning modern hygienic design principles, filter cloths are only designed for efficient filtration performances, in which cleanability is not considered. Hence, in combination with strongly adhesive spent grains, brewers often reject mash filters. The paper illustrates an experimental parameter variation and a comparison of pulsed with continuous cleaning in respect to their cleaning performance. The results showed that the proposed method is suitable, reaching up to 30% higher cleaning degrees than conventional methods. Furthermore, the technique required up to 50% fewer cleaning fluids and shorter cleaning times, indicating economic and ecological advantages.     

An experimental investigation into structure and properties of 3D-woven aramid and PBO fabrics

Three-dimensional (3D) fabrics are the focus of recent developments due to their versatile physical, structural attributes, and application scopes. These fabrics can be manufactured in various architectures which offer a great deal of opportunity to modify the weight, physical and mechanical properties, and cost of the various products. The potential usage of 3D woven fabrics in the ballistic protection applications was the main motivating factor of this research work. Thus, interest has been focused to investigate the structure and properties of 3D woven orthogonal fabrics with aramid fiber and PBO fiber in comparison with 2D fabrics. The investigation of ballistic properties of these fabrics showed that 3D woven fabrics are superior in terms of breaking load and energy absorption as compared to those of 2D woven fabrics. The specific ultimate tensile strength of 3D woven fabric was observed to be lower than 2D fabrics, which may be due to less number of load bearing yarns in the loading direction. The crimp percentages of the load bearing tows in 3D fabric are very less than that of 2D fabrics. Owing to the higher values of work at peak and load at peak, in knife penetration test, it is revealed that 3D fabrics offer better protection than 2D fabrics.     

Influence of graphene oxide concentration and dipping cycles on electrical conductivity of coated cotton textiles

The electrical conductivity of cotton fabrics is enhanced by coating with graphene in aqueous phase by a suitable process. Two different types of fabrics viz. woven and knitted structures of same GSM are used as substrate. The fabrics are dipped in dispersed graphene oxide (GO) solution and then GO-enriched fabric samples are subjected to a reduction process for in-situ conversion of the added GO to electro-conductive graphene. The concentration of GO solution and number of dipping cycles influence the graphene add-on and electrical resistivity of the fabrics. The change in surface resistivity, thickness, air permeability, porosity and water vapour permeability of the fabrics after the treatment has been evaluated. Comparisons have been made between the woven and knitted fabrics for all these properties to understand the effect of fabric structure.     

Theory of multilayer woven structures

Multilayer woven fabrics are conventionally represented with the usual weave notation of black and white squares. This notation is based on the top view of the woven fabric. Side view of multilayer woven fabrics contains more important information, namely the routes of warp yarns between layers of weft yarns. In this study, possibilities of woven structures with any numbers of layers and corresponding warp and weft yarns are described. Formulas are derived to describe horizontal, vertical, and diagonal symmetries which lead to identify the fully independent structures. The results serve as the theoretical ground to determine all the possible mechanical properties by using woven reinforcements.     

Predictive model for the frictional characteristics of woven fabrics optimized by the genetic algorithm

Surface friction of fabrics is one of the prominent tactile properties which influence the comfort and application of clothes. In this paper, a new approach is proposed to characterize the surface friction of woven fabrics by presenting a model based on fabric structural parameters. The model coefficients are optimized with the aid of the genetic algorithm, using the experimental friction results obtained from the multi-directional tactile sensing mechanism. The model is developed using the properties of 25 groups of woven fabrics consisting of 5 various weave structures and 5 different weft densities, with similar fibre composition. The statistical analysis of Friction results clarified that the effect of fabric structural parameters such as weave structure and weft density is significant in the confidence range of 95%. The importance of proposing the friction model is that the frictional properties of woven fabrics can be estimated by considering the structural parameters of woven fabrics. This model can be utilized for the forecasting of the friction resistance of various types of woven fabrics without experimental testing procedures.     

A Comparison of the Irregularity and Tensile Properties of Worsted Yarns Spun with Travellers of Rectangular and Round Cross-sections

Abstract

This paper presents a method to design a wavelet-filter that minimizes entropy in the wavelet transform of images of woven fabrics. Filters that minimize entropy in images tend to filter out fabric texture while highlighting fabric defects. The design of the wavelet filter is couched as a non-convex optimization problem which is solved using a hybridized Genetic Algorithm. Three distinct filters are tuned to detect horizontal, vertical and blob defects in woven fabrics. In addition to texture filtering, defect segmentation, noise removal, and object extraction are presented. The effects of shifting on the optimized set of coefficients is also explored.     

三维正交整体夹芯机织物的结构设计及织造

以正交结构为基本的三维结构单元,通过改变空心各边的长度和厚度,设计了多种经向截面为六边形的三维整体夹芯机织物结构,并在改造的普通织机上织造成功。在此基础上对试样的结构特点进行对比分析,同时探讨了三维正交夹芯机织物孔形尺寸的影响因素,比较了各种三维整体夹芯机织物试样的结构特点及织造方法。该研究为三维整体夹芯机织物的结构设计提供了参考,设计的多种三维夹芯机织物为蜂窝结构复合材料提供了性能良好的增强体。     

Textiles in air filtration

Fossil fuels are a major source of energy although they generate toxic pollutants that cause harm to human beings and the environment. To control these toxic pollutants, various environmental regulations have been imposed and improved filtration technologies have been developed and adopted in response. Multinational agreements have been signed in order to tackle fossil fuel emission as a global problem. Whilst efforts to reduce emissions include the switch from fossil fuel to renewables such as solar, rain and wind, renewables like solar and wind sources and technologies are currently expensive as compared to fossil-fuel technologies. Nonwoven filter media are currently the dominant means by which the fly ash particles that are generated during fossil-fuel combustion are removed; they are widely used because of their high filtration efficiency and low pressure-drop properties. This issue of Textile Progress focuses on the filtration market, the manufacturing techniques used for nonwoven filters, the filtration of fly ash and the mechanisms used to control emissions to meet environmental regulations. Important properties of filter fabrics, their areas of application and disposal issues are discussed and possible reasons are presented for the failure of filters during operation. It addresses the problems faced in achieving effective filtration, not only in fossil fuel power plants but also across a number of other important industries.     

含湿状态下组织结构对织物热舒适性的影响

为比较不同组织结构的织物在含湿状态下的热舒适性能,用KES织物风格仪测试了在一定含湿状态下涤纶针织物、机织物的热舒适性能。结果表明:织物含水率越高,瞬间冷感越强,热传导性能提高,保暖性能下降;在含湿率相同的状态下,涤纶机织物比针织物瞬间冷感更强;编织方法对导热系数随含湿率变化的规律没影响;涤纶机织物、针织物在纯干燥状态下的保暖性相差无几,但加湿后2种织物保暖性能差别显著。通过综合分析比较,认为涤纶针织物保暖性好于涤纶机织物。     

The Comparison of Woven Fabrics by Reference to Their Tightness

The paper outlines a method for comparing the tightness of two woven fabrics. The tightness of a woven fabric is determined with reference to the nearest maximum-sett fabric to the given fabric. The purpose is not to categorise woven fabrics in terms of their tightness but to enable fabrics to be designed with reference to other known fabrics, tightness being used as the basis for comparison.     

三维机织预型件的织造技术

纺织复合材料预型件的生产工艺有多种,其生产路径主要由最终用途决定。三维机织物是通过对传统织造原理改进加工而成的。二维机织复合材料是一种由二维织物构成的层合材料,而三维机织复合材料是复杂几何结构的整体构件。三维机织复合材料预型件有许多优点,最重要的优点是它避免了二维层合材料的分层现象。介绍了三维机织预型件的织造方法,为纺织复合材料的开发提供了有益的借鉴。     

Mechanical Properties of Composite Panels Reinforced with Integrally Woven 3-D Fabrics

An investigation is reported in which six three-dimensional cellular fabrics were designed and woven. They consisted of two facings connected by an integrally woven sinusoidal core. In lateral compression, the ratio of the cell-repeat distance to the fabric thickness determines the resistance of the fabrics to buckling. Composite panels were fabricated by impregnating the fabrics with resin. Formulae developed allow the cross-sectional area and second moments of area of the panels to be calculated. Tensile tests were performed on the panel facings and whole structures to measure the Young's moduli and strengths in the longitudinal (weft) and transverse (warp) directions. Flexural tests were made to measure the beam flexural rigidities. The structural analysis of the beam sections together with the tensile properties of the beams enables flexural properties to be accurately predicted. The properties of the 3-D beams in flexure are comparable to those of other engineering materials, but the fabric-based, cellular composites will have advantages as components in composite structures.     

Investigation on filtration properties of polyester needle-punched dust filter

Abstract

In nonwoven filter fabrics, virgin polyester fibre is mostly used. Therefore, this study has been conducted with the use of virgin polyester fibre and recycled polyester fibre which is obtained after recycling of post-consumer bottle flakes to reduce the cost of filter fabric. The study is concerned to examine the effect of fabric GSM (grams/m²), needling density and depth of needle penetration on filtration efficiency and also to see the suitability of recycled polyester fibre in place of virgin polyester fibre. The study has shown that the increase in fabric weight resulted in increase in the filtration efficiency percentage. The increase in the depth of needle penetration resulted in increase in the extent of filtration efficiency initially; subsequently, it decreased. Similar trends were observed in case of both recycled polyester filter fabrics and virgin polyester filter fabrics. Though the filtration efficiency of filter fabrics prepared from virgin polyester fibre was slightly higher, the filtration efficiency of fabrics prepared from recycled polyester fibre was lower by only 2 to 3 per cent due to close difference in values of molecular weight (Mw) and polydispersity index (PDI). Therefore, looking to the filtration efficiency percentage, it may be suggested that recycled polyester fibre can be used in place of virgin polyester fibre for the manufacturing of needle-punched nonwoven filter fabrics.     

A Study of the Mechanical Properties of Woven Silk Fabrics. Part I: Fabric Mechanical Properties and Handle Characterizing Woven Silk Fabrics

In order to investigate the soft handle of woven silk fabrics, their basic tensile, bending, shearing, compressional, and surface properties were measured on the KESF system. Fabric shear, compressional, and tensile properties distinguish continuous-filament silk fabrics from fabrics of other fibres. Shear stiffness and hysteresis in shear force are very small, and these fabrics are very deformable in their compressional and tensile properties at small strain levels.

High values of FUKURAMI are a characteristic of continuous-filament woven silk fabrics.