Indian Journal of Fibre & Textile Research

VOLUME  27

NUMBER  3

SEPTEMBER 2002

CONTENTS

 

Thermal conductivity of unidirectional fibre composites made from yarns and computation of thermal conductivity of yarns
S Kawabata & R S Rengasamy

 

217

 

 

Effect of process variables on the properties of air-jet textured yarns using response surface design
Deepali Palta & V K Kothari

 

224

 

 

Influence of frictional characteristics of core and sheath in relation with core-sheath ratio and spinning drums’ speed on tensile characteristics of DREF-3 friction-spun yarns
K R Salhotra, S M Ishtiaque & R V M Gowda

 

 

230

 

 

Structure and properties of polyester MJS plied yarns
G K Tyagi, A Patnaik,  A Goyal, K R Salhotra & S M Ishtiaque

236

 

 

Generating textile designs using cellular automata
S Rajasekaran & R Amalraj

242

 

 

Prediction of fibre quality from anatomical studies of jute stem: Part I ¾ Prediction of fineness
S Majumdar

 

248

 

 

Prediction of fibre quality from anatomical studies of jute stem: Part II ¾ Prediction of strength
S Majumdar

 

254

 

 

Development of protective clothing for pesticide industry: Part II — An ecofriendly approach in selection of resin
Mona Suri & M Chakraborty

 

259

 

 

Modification of cotton fabrics via radiation graft copolymerization with acrylic acid, acrylonitrile and their mixtures
Eglal H K El-Gendy

 

266

 

 

Preparation and characterization of guaran carbamate as a thickener in disperse dye printing pastes
S H Nassar

 

 

274

 

 

Effect of hydrogen peroxide bleaching on sulphonated jute-cotton blended fabric
Md. Ibrahim H Mondal

280

Short Communications

 

Influence of process parameters on hairiness of polyester MJS yarns
G K Tyagi & A Goyal

284

 

 

Mechanical properties of commingled yarn composites
Li Long, Wang Shanyuan & Yu Jianyong

287

Review Articles

 

Aramid fibres – An overview
M Jassal & S Ghosh

290

 

 

Microfibres ¾ An overview
Samrat Mukhopadhyay

307

 

 

Engineering design of woven fabrics¾A recent approach
B K Behera & S B Muttagi

315

Conference  Report

 

Forty-third Joint Technological Conference of ATIRA, BTRA, SITRA and NITRA
J V Rao & A Das

323

 

 

 

 

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 217-223

 

Thermal conductivity of unidirectional fibre composites made from yarns and computation of thermal conductivity of yarns

S Kawabata & R S Rengasamy

Received 1 March 2001; accepted 6 July 2001

Measurement of thermal conductivity of fibre composites made from different fibre assemblies (yarns) consisting of apparel, industrial and high performance fibres is described. From the measured thermal conductivity values of composites, the computation of longitudinal and transverse conductivity of yarns is reported. The thermal conductivity of yarn along its axis is much higher than the thermal conductivity in transverse direction for all types of fibres, except E-Glass, showing that the phenomenon of thermal conductivity of fibres is anisotropic in nature. The behaviour of E-Glass in conducting the heat is close to isotropic. Polyethylene filament yarn shows the highest anisotropy followed by Vectron, Kevlar, Technora, linen, high-tenacity polyester and jute. For the fibres of same chemical structure, high-tenacity fibres have slightly higher longitudinal and lower transverse thermal conductivity values compared to apparel-grade fibres. Industrial-grade polyester and nylons have high anisotropy in conducting heat than the apparel-grade fibres. The effect of fibre chemistry on the thermal conductivity of fibres is predominant than the effect of orientation of the molecules.

Keywords: Anisotropy, Composites, Longitudinal conductivity, Thermal conductivity, Transverse conductivity

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 224-229

 

Effect of process variables on the properties of air-jet textured yarns using response surface design

Deepali Palta & V  K Kothari

Received 4 April 2001; accepted 19 June 2001

The effect of the main process variables, namely overfeed, air pressure and texturing speed, on the properties of air-jet textured yarns produced from three different polyester POY yarns of 115/36, 115/48 and 115/72 deniers has been studied.  The interaction between the process variables has been taken into consideration by using response surface methodology based on the Box-Behnken design without producing samples with all the possible combinations of process variables. The response surface graphs obtained by varying two variables at a time keeping the third variable at a constant level have been studied and some of the graphs for air-jet textured yarns produced from 2 ends of 115/48 denier yarns are presented and discussed. The physical bulk of air-jet textured yarns increases significantly with the increase in overfeed and air pressure whereas it slightly decreases with the increase in texturing speed. The instability increases with the increase in overfeed and texturing speed while it decreases with the increase in air pressure. The tenacity values show a decreasing trend with all the three process parameters, i.e. overfeed, air pressure and texturing speed. The overfeed is found to be the most dominant process parameter out of the three parameters studied. The interaction effect of overfeed and air pressure is maximum on the physical bulk while the interaction of texturing speed and overfeed has the least effect. The interaction effect of texturing speed and overfeed on instability is maximum while that of overfeed and air pressure is the least. The response surfaces of yarn tenacity indicate that there is a significant interaction between air pressure and texturing speed whereas the interaction effect is least in case of overfeed and texturing speed.

Keywords: Air-jet texturing, Box- Behnken design, Physical bulk, Polyester yarn, Response surface design, Tenacity

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 230-235

 

Influence of frictional characteristics of core and sheath in relation with
core-sheath ratio and spinning drums’ speed on tensile characteristics of
DREF-3 friction-spun yarns

K R Salhotra, S M Ishtiaque & R V M Gowda

Received 13 March 2001; revised received and accepted 20 June 2001

The influence of frictional characteristics of core and sheath, core-sheath ratio, and spinning drums’ speed on the tensile characteristics of DREF-3 friction-spun yarns has been studied. The increase in fibre-to-fibre friction due to the increase in the level of add-on finish on core fibres/sheath fibres/both the fibres increases the yarn tenacity, initial modulus and energy-to-break. The tenacity increases by 18% for ~ 9-14% increase in fibre-to-fibre frictional force due to the increase in PEG-600 finish from 0% to 0.4%. For the same level of AVF-5/32 finish, the fibre-to-fibre frictional force increases by
~ 14 -19% which results in 20% increase in tenacity. The increase in fibre friction does not affect the yarn breaking extension but significantly increases the initial modulus. The core-sheath ratio of 70:30 results in maximum yarn tenacity, initial modulus and energy-to-break. The increase in spinning drums’ speed from 3500 rpm to 5000 rpm increases the tenacity; the improvement in yarn tenacity is however maximum at lower level of fibre friction and vice versa. The maximum tenacity is achieved at 5000 rpm spinning drums’ speed and higher level of friction.

Keywords:   Add-on finish, Core-sheath ratio, DREF-3 yarn, Frictional characteristics, Initial modulus, Yarn       tenacity

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 236-241

 

Structure and properties of polyester MJS plied yarns

G K Tyagi, A Patnaik ,  A Goyal, K R Salhotra & S M Ishtiaque

Received 23 March 2001; revised received and accepted 21 August 2001

The influence of ply twist and twist direction on the structure and properties of polyester MJS yarns has been studied. It is observed that the effect of plying on fibre and yarn structural parameters is significant. If the direction of Z-wrapped surface fibres is coincident with the direction of ply twist, the helix angle and helix diameter are high, but the mean fibre extent is very low. The increase in ply twist factor results in larger helix angle, larger helix diameter, smaller yarn diameter and lower fibre extent. Yarn properties also remarkably improve after plying. The improvement in yarn properties depends upon the amount and direction of ply twist. A plied yarn produced by twisting in a direction opposite to that of wrapping of surface fibres is stronger, less extensible, less rigid, more even, and has higher abrasion resistance. Yarns plied in the Z- direction are more rigid than those plied in the S-direction. While the flexural rigidity of yarns plied in the S-direction with higher ply twist factor is considerably lower than that of the corresponding single yarns, the flexural rigidity of those yarns ply twisted in the Z - direction invariably decreases as the ply twist factor is increased.

Keywords : Air-jet spinning, Flexural rigidity, MJS yarn, Plying, Polyester yarn, Yarn properties

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 242-247

 

Generating textile designs using cellular automata

S Rajasekaran & R Amalraj

Received 19 April 2001; revised received and accepted 14 September 2001

Cellular automata (CA) are discrete dynamical systems of simple construction but complex and varied behaviour. Algebraic techniques are used to give an extensive analysis of the global properties of a class of finite cellular automata. The rule numbers in one-dimensional automata ranging from 0 to 255 have been tested and found to generate mostly geometric patterns. In two-dimensional automaton, the various rule numbers have been tested in 80´80 matrix with a grid size of five pixels and the matrix size extended to 110´110 with a grid size of three pixels each that resulted in chaotic, stable and high life. The behaviour of the neighbourhood cells has been analyzed by their categories, grouped together and represented graphically, resulting in uniform and non-uniform patterns, which may well be utilized for textile designs. The algorithm is designed with an option to generate the rule number itself randomly and hence the design generated is highly unpredictable and it is observed that different patterns are generated to each iteration of the algorithm.

Keywords: Cellular automaton, Textile design

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 248-253

 

Prediction of fibre quality from anatomical studies of jute stem:
Part I
¾Prediction of fineness

S Majumdar

Received 8 November 2000; revised received and accepted 2 August 2001

Some structural parameters of fibre bundles, as revealed by the microscopical study of the transverse section of jute plant stems, have been found to have high positive correlations with filament fineness of extracted fibres. Equations have been derived by linear regression analysis to predict the fineness of extracted fibres. The study would not only be very helpful in selecting the fine fibre producing plants in breeding programmes, but will also provide some information on the structure -quality relationship of jute fibre, necessary for genetic upgradation of fibre quality.

Keywords: Anatomical study, Fibre fineness, Jute fibre

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 254-258

 

Prediction of fibre quality from anatomical studies of jute stem:
Part II
¾ Prediction of strength

S Majumdar

Received 14 December 2000; revised received and accepted 2 August 2001

The tenacity values of bundles of jute fibres belonging to different varieties have been predicted from the structure of their fibre bundles as seen in the transverse section of jute stems and the length of the constituent ultimate cells by multivariate regression analysis. Jute plant stems having fibre bundles comprising greater number of compactly arranged long and fine ultimate cells give fibres of higher strength when retted under standard conditions.

Keywords : Anatomical study, Jute fibre, Tenacity

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 259-265

 

Development of protective clothing for pesticide industry: Part II ─ An ecofriendly approach in selection of resin

Mona Suri  & M Chakraborty

Received 23 January 2001; revised received and accepted 31 July 2001

Two low formaldehyde-based resins along with one normal resin based on DMDHEU have been applied separately as well as along with fluorocarbon finish on 100% cotton and 70/30 polyester-cotton blended fabrics in varying concentration and their effects on add-on, durability in terms of water and oil repellency and tensile strength studied to make the finishing process more ecofriendly and suitable for its use in protective clothing for pesticide industry. The resins have also been evaluated in terms of their influence on water vapour permeability, creasing behaviour, stiffness and free formaldehyde content of the finished fabrics. It is observed that the type of resin and its concentration affect the durability of fluorocarbon finish to laundering. Glyoxal-based resin exhibits minimum free formaldehyde content, minimum loss in strength and better durability to laundering even at lower concentration. The optimized recipe consists of the fluorocarbon finish, glyoxal-based resin, magnesium chloride as a catalyst and a softener applied in acidic conditions, and could be used to prepare the dress materials suitable for the persons working in pesticide industry.

Keywords: Cotton, Fluorocarbons, Polyester-cotton fabric, Protective clothing, Water vapour permeability

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 266-273

 

Modification of cotton fabrics via radiation graft copolymerization with acrylic acid, acrylonitrile and their mixtures

Eglal H K El-Gendy

Received 29 December 2000; revised received and accepted 6 June 2001

Radiation-induced grafting of acrylic acid (AAc), acrylonitrile (AN) and their mixtures onto cotton fabrics has been studied at 2.56 Gy/s gamma dose rate and 1:40 fabric-to-liquor ratio. The grafting process was performed in the presence of aqueous AAc containing 0.75% (owm) Mohr’s salt, and 65:15 methanol-water mixture for AN. The effect of monomer concentration and irradiation time (dose) on the degree of grafting has also been investigated. The dependence of the initial grafting rate on monomer concentration follows a second order kinetics for AN and a negative first order one for AAc. Grafts from monomer mixtures  show different kinetic behaviour, depending on AN/AAc ratios in solutions with constant monomers mixture concentration of 20%. The degree of grafting increases with the increase in AN/AAc ratio from 20/80 to 80/20 for all the doses applied. The reaction order changes from a positive order of 0.55 to a negative order of 0.41 as the ratio of AN/AAc decreases. The swelling properties of cotton fabrics improve with the increase in degree of grafting of AAc and deteriorate with the increase in graft yield of AN. Fabrics grafted with monomer mixtures show swelling behaviour between those of AAc and AN. The electrical conductivity of grafts prepared from the monomers or their mixtures shows a fast initial decrease followed by a tendency to level-off as the graft yield increases up to 35%, irrespective of the type of monomer or the mixture ratio. The dyeability of cotton fabrics towards Sandocryl Blue B-3G, a basic dye, improves considerably as the graft yield with AAc increases up to 20% with no further appreciable changes for higher degrees of grafting. Grafts with AN and AAc/AN mixtures show lower dyeing affinity than that for AAc grafts. The pH of the dye bath affects considerably the dyeability of the grafted fabrics, giving an optimum condition at pH 3.9. Proposed schemes for grafting and dyeing of cotton fabrics with Sandocryl Blue B-3G are given.

Keywords: Acrylic acid, Acrylonitrile, Cotton, Dyeing, Radiation-induced grafting

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 274-279

 

Preparation and characterization of guaran carbamate as a thickener in disperse dye printing pastes

S H Nassar

Received 31 July 2000; revised received 27 July 2001; accepted 30 October 2001

Guaran gum has been isolated from guar seeds and subjected to chemical modification via carbamation using different concentrations of urea. The guaran carbamate samples were analyzed for nitrogen. The results show that the maximum nitrogen content is obtained on using 8g urea/20g guaran gum at 150°C for 30 min and further increase in urea concentration is accompanied by a decrease in the nitrogen content. The printing pastes of these derivatives are characterized by a non-Newtonian pseudoplastic behaviour and their apparent viscosity decreases with the increase in nitrogen content. The utilization of guaran carbamate, either alone or in a mixture with a synthetic thickener Carbopol, in printing polyester fabrics with disperse dyes has also been studied. It is observed that the K/S values and fastness properties of the samples treated with guaran derivatives are nearly comparable with those of the samples printed using Carbopol alone.

Keywords: Carbopol, Disperse dye, Guaran carbamate, Polyester fabric, Printing paste

 

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 280-283

 

 

Effect of hydrogen peroxide bleaching on sulphonated
jute-cotton blended fabric

Md. Ibrahim H Mondal

Received 25 April 2001; revised received and accepted 24 August 2001

 

Raw sulphonated jute, raw sulphonated jute-cotton and cotton fabrics were bleached under different conditions by varying pH, treatment time, temperature, hydrogen peroxide concentration and fabric-liquor ratio. Bleaching affected the brightness and breaking strength, and the optimum brightness (76.9%) and breaking strength (13.6 kg/f) for the blended fabric were obtained with 6.5% hydrogen peroxide at pH 11, temperature 90 oC, treatment time 100 min and fabric-liquor ratio 1:3. The thermal degradation of bleached sulphonated jute-cotton fabric was characterized by TG analysis and compared with the bleached cotton and bleached sulphonated jute fabrics. It has been observed that the thermal stability as well as brightness and breaking strength of the blended fabric largely depend on the amount of lignin and hemi-cellulose present in the fabric sample.

Keywords: Bleaching, Breaking strength, Thermal degradation

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 284-286

 

 

Influence of process parameters on hairiness of polyester MJS yarns

G K Tyagi & A Goyal

Received 19 March 2001; revised received and  accepted 4 July 2001

The influence of processing parameters on the hairiness of polyester MJS yarns has been studied. It is observed that the spinning speed has considerable influence on the hairiness followed by the first nozzle pressure. For a constant first nozzle pressure (2.0 or 2.5 or 3.0), an increase in spinning speed from 180 m/min to 200 m/min increases the yarn hairiness. The hairiness decreases with the decrease in fibre denier, main draft and yarn linear density, and on annealing. Plying also significantly reduces the yarn hairiness; the reduction is more in Z-ply yarns and it increases with the increase in ply twist.

Keywords: Air-jet spinning, First nozzle pressure, Main draft, Polyester yarn, Yarn hairiness

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 287-289

 

 

Mechanical properties of commingled yarn composites

Li Long, Wang Shanyuan & Yu Jianyong

Received 22 May 2001; revised received and accepted 18 September 2001

The unidirectional thermoplastic commingled yarn composites have been fabricated from three different varieties of yarns in a hot press and then studied for the bending properties on DCS-500 tester using three-point loading system. It is observed that the bending properties of composites, especially the transverse bending properties, are affected by the mixing degree of reinforcing fibre/matrix fibres and bulkiness of reinforcing fibres bundle.

Keywords: Air-jet commingling, Glass fibre, Polypropylene

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 290-306

 

 

Aramid fibres – An overview

M Jassal  & S Ghosh

Received 16 July 2001; accepted 24 September 2001

The history, preparation and structure of aramids in general and of Nomex and Kevlar aramid fibres in particular are discussed. The structure-property correlation and the application areas of these fibres are reviewed. Aramid fibres are characterized by their superior thermal properties, resistance to chemicals and outstanding mechanical properties.

Keywords: Aramid fibre, Aromatic polyamides, Kevlar, Liquid crystalline spinning, Nomex, Technora

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 307-314

 

Microfibres ¾ An overview

Samrat Mukhopadhyay

Received 6 June 2001; revised received and accepted 18 December 2001

A microfibre can be polyester, nylon, acrylic, rayon or lyocell, spun in such a way so that the filaments are finer than 1.0 denier. The article is an overview on some of the important developments that have taken place in the field of microfibres. The interesting applications of microfibres in various fields have introduced leading fibre manufacturers like DuPont, BASF, Hoechst, Trevira, Teijin, Lenzing and Wellman make their own brands of microfibres. Nevertheless, high cost, lack of experimentation, less research in the field of new machinery and want of expertise to handle these fibres have hindered the growth of the microfibre market. These areas need particular attention if the potential of this fibre is required to be tapped.

Keywords: Artificial leather, Bi-component fibres, Microfibres, Texturing

 

 

Indian Journal of Fibre & Textile Research

Vol. 27, September 2002, pp. 315-322

 

Engineering design of woven fabrics¾A recent approach

B K Behera & S B Muttagi

Received 5 May 2000; revised received and accepted 20 December 2001

The fabric engineering is still largely based on experience and trial and error. The major task is to develop comprehensive and user-friendly program packages with database on fibre, yarn and fabric properties by the application of fabric objective measurement technology, a knowledge-based expert system to provide graphical tools and numerical solutions for the fabric designer and engineer to meet the needs of fabric manufacturers. Compared to mathematical modeling, artificial neural network can be a powerful tool to model the non-linearities and complexities involved in the predictions of fabric proprieties. Artificial neural network embedded expert system can be developed to aid in engineering the design of woven fabric.

Keywords: Artificial neural network, Computer-aided designing, Fabric engineering, Woven fabric