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1 – 10 of over 1000Abstract
The limiting irregularity of yarn is the minimum count variation expected from ideal yarn with a random fibre ends distribution. It can be calculated with the Martindale limiting irregularity model which takes into account the changes in the number of fibres in yarn crosssection and the variations in fibre cross-sectional areas. However, the variations in fibre cross-sectional areas are calculated from between-fibre diameter variations only, without considering the within-fibre diameter variations. Wool fibres exhibit diameter variations both between fibres and within fibres. Ignoring the within-fibre diameter variations may lead to an underestimation of yarn limiting irregularity. This paper reports an improved model for calculating the limiting irregularity of wool yarn, incorporating both between-fibre and within-fibre diameter variations of the constituent wool fibres. Experimental verification shows that this model can predict yarn limiting irregularity more accurately than the existing one. Based on this improved yarn limiting irregularity model, an improved effective fineness model which also incorporates both within-fibre and between-fibre diameter variations has been established.
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Ravi Kumar Jain, Sujit Kumar Sinha and Apurba Das
Spunlacing is a promising nonwoven technology for the production of fabric with good handle and better structural integrity. Structural parameters such as pore size, thickness and…
Abstract
Purpose
Spunlacing is a promising nonwoven technology for the production of fabric with good handle and better structural integrity. Structural parameters such as pore size, thickness and number of binding point/entanglement between fibres are decisive for good mechanical and comfort properties of nonwoven fabrics. This study aims to focus on the effect of different process parameters on the structural change in spunlace fabrics.
Design/methodology/approach
Spunlacing is purely a mechanical bonding technology where high-speed jets of water strike a web to entangle the fibres. Different spunlace nonwoven structures were produced by varying processing parameters such as waterjet pressure, delivery speed, web mass and web composition as per four-factor, three-level Box–Behnken design. The effect of these parameters on the structural arrangement was studied using scanning electron microscopy. An attempt has also been made to study the changes in pore geometry and thickness of the fabrics by using response surface methodology with backward elimination.
Findings
Significant structural changes were observed with variation in water pressure, web mass and web composition. The test results showed that fabric produced at higher waterjet pressure has lower mean pore diameter and lower thickness. The variation in mean pore diameter and mean thickness due to waterjet pressure is around 26 and 34 per cent, respectively, at 95 per cent significance level. The web composition and web mass also significantly influence the mean pore diameter and thickness at 95 per cent significance level. There is a strong positive correlation (r = 0.523) between mean air permeability and mean pore diameter of fabric, and this correlation is significantly linear. A strong negative correlation (r = −0.627) is found between weight and air permeability of fabric.
Research limitations/implications
The delivery speed failed to show any significant effect; this is in contrary to the general expectation.
Originality/value
The effect of concurrent variation in waterjet pressure, web mass, delivery speed and web composition on the structure of spunlace nonwoven is studied, which was not reported in the literature. The effect of web composition on pore diameter of spunlace nonwoven is interesting finding. This study is expected to help in designing the spunlace nonwoven as per end uses and specifically for apparel application.
Maryam Naebe, Bruce McGregor, Melanie Dowling and David Tester
The purpose of this paper is to identify the significant factors important for prickle discomfort properties of commercial wool knitwear and to analyse information on variability…
Abstract
Purpose
The purpose of this paper is to identify the significant factors important for prickle discomfort properties of commercial wool knitwear and to analyse information on variability of garments manufactured over two decades, a total of 177 purchased garments were tested.
Design/methodology/approach
The relationship between the attributes of the reversed engineered garments and garment comfort, as assessed by Wool ComfortMeter, was determined.
Findings
The results indicate that: mean fibre diameter had the most significant effect on prickle assessment; the coefficient of variation of fibre diameter interacted with fabric thickness in affecting prickle discomfort; and rib knit structures were pricklier than single jersey structures.
Originality/value
The results provide objective evidence that the consumer surveys reporting dissatisfaction with the prickle discomfort of wool are based on real consumer experiences of prickle discomfort and are not based on “prejudice” against wool garments.
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Inter-fibre cohesion is regarded as an important property of assemblies, such as slivers, made of wool or any other fibres, with respect to the processing in carding, drawing…
Abstract
Inter-fibre cohesion is regarded as an important property of assemblies, such as slivers, made of wool or any other fibres, with respect to the processing in carding, drawing (gilling) and spinning. In this paper, the results of the multiple regression analyses, and their validation, are presented to show that a strong relationship exists between the sliver cohesion (measured as sliver tenacity and sliver specific energy-to-break in a long-gauge tensile test) and a combination of the standard wool properties, such as bulk, mean fibre length (Barbe), mean fibre diameter and medullation content, used for the objective blend specification of New Zealand wools for marketing and processing.
Presents a mathematical treatment of the large‐scale bending behaviour of multi‐ply yarn. Based on the assumptions that: each individual fibre in the yarn has the form of a…
Abstract
Presents a mathematical treatment of the large‐scale bending behaviour of multi‐ply yarn. Based on the assumptions that: each individual fibre in the yarn has the form of a doubly‐wound helix; each fibre is an inextensible slender rod; and interaction between fibres is ignored. The yarn‐bending rigidity is calculated as an average rigidity of an assembly of coaxial helices. There is good agreement between the predicted and measured values of yarn bending rigidity for a wool worsted knitting yarn. Also predicts the position, curvature and twist components as well as the strain energy of the deformed fibre.
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Mashford Zenda, Paul Malan and Antonie Geyer
South Africa’s wool industry plays an important role in the agricultural sector. The wool industry provides a valuable source of income for farmers who practice sustainable…
Abstract
Purpose
South Africa’s wool industry plays an important role in the agricultural sector. The wool industry provides a valuable source of income for farmers who practice sustainable farming practices. However, wool farmers face numerous challenges, such as wool contamination, dirty wool and producing good-quality wool. Good-quality wool is determined by fibre diameter, clean yield, vegetable matter and staple length. This study aims to address these challenges.
Design/methodology/approach
A multiple regression analysis of price (R/kg) of White wool and Merino wool was applied to four variables fibre diameter: vegetable matter, clean yield and staple length. The analysis was based on the data for the 2009–2019 data from Cape Wools auctions.
Findings
Fibre diameter, clean yield and staple length, with exception of vegetable matter, made a statistically significant contribution to the determination of wool price after all other independent variables were controlled for (p < 0.05). A one-unit (micron) increase in fibre diameter resulted in a 0.404-unit decrease in wool price (R/kg). A one-unit (mm) increase in staple length resulted in a 0.022-unit increase in wool price (R/kg). There was no statistically significant association between vegetable matter and wool price. A one-unit increase in clean yield was associated with a 0.111-unit increase in wool price (R/kg).
Research limitations/implications
Since wool fleeces consist of the largest portion of wool shorn from sheep, it is important for wool farmers to focus on wool with low fibre diameter, high clean yield percentage, low percentage of vegetable matter content and good length of the wool.
Practical implications
Since wool fleeces consist of the largest portion of wool shorn from sheep, it is important for wool farmers to focus on wool with low fibre diameter, high clean yield percentage, low percentage of vegetable matter content and good length of the wool.
Social implications
In a developing country such as South Africa, this study is important for the following reason. It is understanding the wool characteristics that have the most significance influence on the determination of wool price for Merino wool and White wool might effectively help the wool farmers to adapt their production systems to improve the wool characteristics that determine wool price.
Originality/value
This study identified a need for a study to be conducted on all wool classes.
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Examines the tenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects…
Abstract
Examines the tenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.
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Examines the fifthteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…
Abstract
Examines the fifthteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.
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T.P. Sperring, D.T. Gethin and J.O. Medwell
A combined experimental and numerical investigation into the fluid flow and heat transfer processes that take place in the spray deposition of tubular preforms is presented. The…
Abstract
A combined experimental and numerical investigation into the fluid flow and heat transfer processes that take place in the spray deposition of tubular preforms is presented. The work is concerned principally with impingement mechanisms at jet diameter to target distances that are large in comparison with previous reported studies. The experimental investigation required the design of a novel heat transfer meter that was capable of resolving the heat transfer coefficient within 2.5 per cent. The experiments gave a new correlation for stagnation heat transfer, similar in form to correlations that have been published for small jet diameter to target distance values. The experiments also showed the presence of skewing of the heat transfer coefficient in the deposition zone due to its tapered nature. A finite volume based model of the deposition chamber was developed and run to compare with the experimental data. This model was found to yield trends similar to those measured experimentally, thus confirming its qualitative capability. However the absolute values of heat transfer coefficient that were computed were significantly lower than measured values. This points to the requirement to consider alternative computing schemes and to investigate the methods of representing the heat transfer mechanisms at the physical boundaries, particularly at the preform surface.
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Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…
Abstract
Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.
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