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Article
Publication date: 1 February 2014

Subhasis Das and V. K. Kothari

The moisture vapour permeability properties of a series of almost similar polyesterviscose (P/V) and polyester-cotton (P/C) blended fabrics are investigated. The water…

Abstract

The moisture vapour permeability properties of a series of almost similar polyesterviscose (P/V) and polyester-cotton (P/C) blended fabrics are investigated. The water vapour transport rate greatly differs depending on the principle of the test methods, even when other parameters are nearly identical, such as air permeability, areal density, porosity and thickness. The water absorption characteristics of fibre seem to be the most important in determining the overall water vapour transport rate. Substitution of polyester for viscose and cotton in P/V and P/C blended fabrics respectively, reduces the water transport rate of the fabrics in a long term method. It is found that the P/C blended fabrics show greater water vapour transport than the corresponding P/V fabrics when a long term test method is used; however, the P/V fabrics show relatively higher water vapour permeability than the P/C fabrics when short duration tests are carried out by using the Permetest and moisture vapour transmission rate (MVTR) cell methods

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Article
Publication date: 1 August 2011

V K Kothari, S Dhamija and R K Varshney

Mechanical properties of 100% polyester and polyester-viscose (P/V) blended yarns produced from polyester fibres which vary in denier and cross-sectional shape have been…

Abstract

Mechanical properties of 100% polyester and polyester-viscose (P/V) blended yarns produced from polyester fibres which vary in denier and cross-sectional shape have been analyzed. It is observed that fibre fineness and cross-sectional shape play a significant role in the translation of fibre properties to the respective yarn properties. As the fibre linear density decreases, fibre strength translation efficiency increases. In the case of trilobal fibre, translation efficiency is observed to be lower, but yarn breaking elongation is higher in comparison to the corresponding circular fibre. Scalloped oval fibre contributes more towards yarn strength and elongation versus the equivalent circular and tetraskelion fibres. In the P/V blended form, a decrease in yarn tenacity does not affect fibre fineness, but is substantially influenced by changes in the fibre profile. Contribution of broken viscose fibres (comparatively weaker component) at the point of actual breaking of yarn, i.e. Z-value, is altered depending on the polyester fibre profile, which is higher in trilobal and scalloped oval fibres in comparison to the corresponding circular ones, but the role of fibre linear density in this regard is rendered insignificant.

Details

Research Journal of Textile and Apparel, vol. 15 no. 3
Type: Research Article
ISSN: 1560-6074

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Article
Publication date: 4 May 2018

Gnanauthayan G., Rengasamy R.S. and Vijayakumar Kothari

This paper aims to deal with the thermal resistance of multilayer nonwovens. The effect of fibre denier, cross-sectional shape and positioning within the layers were…

Abstract

Purpose

This paper aims to deal with the thermal resistance of multilayer nonwovens. The effect of fibre denier, cross-sectional shape and positioning within the layers were analysed with respect to the thermal resistance. Moreover, effect of compression on thermal resistance of the multilayer nonwoven structure have also be studied.

Design/methodology/approach

The study involves multiple layering of thermal bonded nonwoven webs and the effect of fibre denier and positioning of different nonwovens from the hot plate. To avoid the increase in thermal resistance because of the air gaps between layers, the nonwovens were enclosed within an acrylic frame to compress them to a thickness of 12 mm. Compressional behaviour of the nonwovens were tested at a rate of 5 mm/min with peak compressive load of 50 N. Multilayer nonwoven assemblies were tested for thermal resistance with compressive pressure of 3.5 gf/cm2 and compared with that tested at zero pressure.

Findings

In the study, three-layered nonwoven structure, provided better thermal resistance than their single component counterparts. The structural characteristic of the multilayer nonwovens affected the conductive, convective and the radiative heat transfer. In a multi-layer nonwoven, the top most layer should have the finest fibre as possible. Second preference may be given to the middle and followed by bottom layers in terms of fibre fineness. However, fine solid fibres performed poorly in terms of compression and recovery resulting in poor thermal resistance under compressive load.

Originality/value

The experimental approach of controlling thickness while evaluating the thermal resistance will help in nullify the effect of air gaps between the layer interface, thus focussing on the effect of fibre denier and the positioning of nonwovens. This paper also discusses the unique properties of fine solid fibre and hollow fibres and their role in providing better thermal insulation for extreme cold weather applications.

Details

Research Journal of Textile and Apparel, vol. 22 no. 2
Type: Research Article
ISSN: 1560-6074

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Article
Publication date: 1 April 2002

A. Mukhopadyhay, A.K. Dash and V.K. Kothari

The effect of pick density, constituent filament fineness and heat‐setting on the fabric thickness and compressional properties have been studied before and after…

Abstract

The effect of pick density, constituent filament fineness and heat‐setting on the fabric thickness and compressional properties have been studied before and after laundering. With the increase in pick density fabric thickness, compression and compressibility increases up to a certain extent. Coarser filament textured yarn fabric have higher thickness, compression and compressibility than that of finer filament textured yarn fabrics. Heat‐set fabrics possess higher thickness, compression and compressibility than the grey textured yarn fabrics. However, fabric compressional recovery and resiliency are mainly influenced by the fabric pick density rather than the effect of heat‐setting and filament fineness of constituent textured yarns. On laundering, fabric thickness, compression and compressibility improve particularly for the fabric of lower pick density. The effect of laundering is marginal on fabric compressional recovery and resiliency.

Details

International Journal of Clothing Science and Technology, vol. 14 no. 2
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 1 May 2008

D. Bhattacharjee and V.K. Kothari

The objective of this paper is to report the values of thermal resistance in natural and convection heat transfer modes through woven fabrics. An instrument developed on…

Abstract

The objective of this paper is to report the values of thermal resistance in natural and convection heat transfer modes through woven fabrics. An instrument developed on the principle of the guarded hot plate method will be discussed. The instrument is precise up to two decimal places and the accuracy is approximately 14%. The fabrics were tested in a natural as well as forced convective mode with air velocity of 1m/s flowing parallel over the fabric surface. It was observed that the thermal resistance of the fabric in forced convection is less than that in the natural convective mode.

The thermal resistance can be predicted with the help of a statistical model when all the constructional parameters are taken together. A polynomial equation consisting of linear, interaction and square terms based on the response surface modelling was developed for both the conditions of heat flow. It was observed that as all constructional parameters, such as warp and weft count, thread spacing, thickness, fabric weight and porosity are taken as variables, the response function; namely thermal resistance can be predicted with a high coefficient of determination and less average error.

Details

Research Journal of Textile and Apparel, vol. 12 no. 2
Type: Research Article
ISSN: 1560-6074

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Article
Publication date: 12 June 2009

Vinay Kumar Midha, V.K. Kothari, R. Chatopadhyay and A. Mukhopadhyay

In this paper, the contribution of dynamic loading, needle and fabric, and the bobbin thread interaction on the changes in the tensile properties of the needle thread are…

Abstract

Purpose

In this paper, the contribution of dynamic loading, needle and fabric, and the bobbin thread interaction on the changes in the tensile properties of the needle thread are to be investigated.

Design/methodology/approach

Tensile properties of the needle thread have been studied at four sewing stages, namely before being subjected to any loading, after dynamic loading, before bobbin thread interaction and after sewing.

Findings

It is observed that bobbin thread interaction plays a dominant role in the reduction of tensile properties except breaking elongation in cotton threads. Dynamic loading is mainly responsible for reduction in the breaking elongation of cotton threads. During sewing, there is an increase in initial modulus due to the dynamic loading, which is more in the case of cotton threads than polyester threads. However, the impact of dynamic loading on tenacity, breaking elongation and breaking energy is greater for coarser cotton thread. The contribution of bobbin thread interaction is more for fine threads as compared to coarse threads.

Practical implications

Since seam strength is dependent on the thread strength, a reduction in thread strength during sewing will lead to lower seam strength than expected. Therefore, in order to minimize the thread strength reduction, it is important to understand the contribution of different machine elements or processes during sewing. During high‐speed sewing, the dynamic and thermal loading are found to be the major causes of strength reduction of needle thread, which can go up to 30‐40 per cent. However, the extent of strength loss at different sewing stages is unknown.

Originality/value

The study will help in engineering sewing threads, designing of sewing machines and selection of process parameters for controlling loss of useful properties of sewing threads.

Details

International Journal of Clothing Science and Technology, vol. 21 no. 4
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 20 April 2015

Ganemulle Lekamalage Dharmasri Wickramasinghe and Peter William Foster

The purpose of this paper is to investigate the use of steam in order to replace air in the production of spun-like textured yarns. Further, this paper analyse the effect…

Abstract

Purpose

The purpose of this paper is to investigate the use of steam in order to replace air in the production of spun-like textured yarns. Further, this paper analyse the effect of production speed on process and textured yarn properties.

Design/methodology/approach

An existing air-jet texturing machine was modified to supply either air or steam to the texturing nozzle. Using standard commercial nozzles, both air-jet and steam-jet textured yarns were manufactured by varying production speed.

Findings

It can be concluded that steam can be used as an alternative fluid for air in making spun-like textured yarns. Results show that yarn parameters for steam-jet texturing show a similar trend to those of air-jet texturing relative to the production speed. Further, sewing threads made from steam-jet textured yarns showed good sewability up to the speeds of 350 m/min.

Research limitations/implications

Only the effect of production speed on process and yarn parameters is discussed in this paper. Production speed was limited to 350 m/min due to machine constraints.

Practical implications

Steam is more economical than air to manufacture spun-like textured yarn at commercial pressures such as 8 bar. Steam-jet textured yarns could be used for commercial applications such as sewing threads at competitive speeds. Further, steam could be generated using sustainable and renewable fuel sources such as biomass.

Originality/value

This research introduced steam as an alternative fluid for air in manufacturing spun-like textured yarns.

Details

International Journal of Clothing Science and Technology, vol. 27 no. 2
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 18 November 2020

Md Vaseem Chavhan and Mandapati Ramesh Naidu

This paper aims to develop at sewing thread during the seam formation may lead to the compression of fabric under seam. In the present study, the model has been proposed…

Abstract

Purpose

This paper aims to develop at sewing thread during the seam formation may lead to the compression of fabric under seam. In the present study, the model has been proposed to predict the seam compression and calculation of seam boldness, as well as thread consumption by considering seam compression.

Design/methodology/approach

The effect of sewing parameters on the fabric compression at the seam (Cf) for fabrics of varying bulk density was studied by the Taguchi method and also the multilinear regression equation is obtained to predict seam compression by considering these parameters. The framework has been set as per the single view metrology approach to measuring structural seam boldness (Bs). One of the basic geometrical models (Ghosh and Chavhan, 2014) for the prediction of thread consumption at lock stitch has been modified by considering fabric compression at the seam (Cf).

Findings

The multilinear regression model has been proposed which can predict the compression under seam using easily measurable fabric parameters and stitch density. The seam boldness is successfully calculated quantitatively using the proposed formula with a good correlation with the seam boldness rated subjectively. The thread consumption estimation from the proposed approach was found to be more accurate.

Originality/value

The compression under seam is found out using easily measurable parameters; fabric thickness, fabric weight and stitch density from the proposed model. The attempt has been made to calculate seam boldness quantitatively and the new approach to find out thread consumption by considering the seam compression has been proposed.

Details

Research Journal of Textile and Apparel, vol. 25 no. 2
Type: Research Article
ISSN: 1560-6074

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Article
Publication date: 5 September 2016

Aman Ganesh, Ratna Dahiya and Girish Kumar Singh

The purpose of this paper is to develop an adaptive fuzzy controller for STATCOM to damp low-frequency inter-area oscillation over wide operating range using wide area…

Abstract

Purpose

The purpose of this paper is to develop an adaptive fuzzy controller for STATCOM to damp low-frequency inter-area oscillation over wide operating range using wide area signals in multimachine power system.

Design/methodology/approach

In this paper tuneable fuzzy model is proposed where the parameters of the fuzzy inference system are tuned by using the adaptive characteristic of the artificial neural network. Based on back propagation algorithm and method of least square estimation, the fuzzy inference rule base is tweaked according to the data from which they are modelled. The wide area control signals, for the proposed controller, available in the power system are selected on the basis of eigenvalue sensitivity defined in terms of participation factor.

Findings

The effectiveness of the proposed controller with wide area signals is tested on two test cases, namely, two area network and IEEE 12 bus benchmark system. The comparative analysis of the proposed adaptive fuzzy controller is carried out with conventional STATCOM controller along with fuzzy-and neural-based supplementary controller all using selected wide area signals. The results show that neural network tuned fuzzy controller leads to better system identification and have enhanced damping characteristics over wide operating range.

Originality/value

In the available literature, numerous researchers have indicated the use of fuzzy logic controller and neural controller along with their hybrid schemes as STATCOM controller for improving the dynamics of the multimachine power system using local signals. The main contribution of the paper is in using the hybrid intelligent control scheme for STATCOM using wide area signals. The advantage of proposed scheme is that the performance of well-designed fuzzy system can be enhanced with the same training data that are used for designing a neural controller thus giving enhanced performance in comparison to individual intelligent control scheme.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 35 no. 5
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 24 August 2018

Krittiya Ongwuttiwat, Sudaporn Sudprasert and Thananchai Leephakpreeda

The purpose of this paper is to present the determination of human thermal comfort with wearing clothes, with different water vapor permeability. Currently, the predicted…

Abstract

Purpose

The purpose of this paper is to present the determination of human thermal comfort with wearing clothes, with different water vapor permeability. Currently, the predicted mean vote (PMV) equation is widely used to determine thermal sensation scales of human comfort. However, moisture permeability of clothes has been not taken in account where the heat is lost from a human body due to water vapor diffusion through clothes.

Design/methodology/approach

In this study, the heat loss is derived based on the real structure of textiles, causing water vapor pressure difference between air on skin and ambient air. The PMV equation is modified to differentiate a thermal sensation scale of comfort although patterns of clothes are the same. Interview tests are investigated with wearing clothes from three types of textiles: knitted polyester, coated nylon–spandex, and polyurethane, under various air conditions.

Findings

The moisture permeabilities of knitted polyester, coated nylon–spandex and polyurethane are 16.57×10−9 kg/m2 s•kPa, 9.15×10−9 kg/m2•s•kPa and 2.99×10−9 kg/m2•s•kPa, respectively. The interviews reveal that most people wearing knitted-polyester clothes have the greatest cold sensations under various air conditions since moisture permeability is the highest, compared to coated nylon–spandex, and polyurethane leather. Correspondingly, the predicted results of the modified PMV equation are close to the actual mean votes of interviewees with a coefficient of determination R2=0.83. On the other hand, the coefficient of determination from the predicted results of the conventional PMV equation is significantly lower than unity, with R2=0.42.

Practical implications

In practice, this quantitative determination on human thermal comfort gives some concrete recommendations on textile selection of clothes for acceptable satisfaction of thermal comfort under various surrounding conditions of usage.

Originality/value

The modified PMV equation effectively determines human comfort on a thermal sensation scale due to the moisture permeability of clothes. To make generic conclusion, experimental results of additional three textiles, such as plain weave/lining polyester, knitted spandex, and open structure polyester, are reported. They confirm that the modified PMV equation effectively determines human comfort on a thermal sensation scale due to the moisture permeability of clothes.

Details

International Journal of Clothing Science and Technology, vol. 30 no. 4
Type: Research Article
ISSN: 0955-6222

Keywords

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