Air permeability and bursting strength of weft-knitted fabrics from glass yarn. Part II: knit architecture effect

In this study; the effects of loop, skip, and tuck stitch types, and weft-inlay yarn, on air permeability and bursting strength of weft-knitted fabrics from glass yarn were revealed. Due to clockwise rotation of wales and their arrangement being one on top of the other, besides the dramatic shortening of fabrics after their removal from the machine; fabrics with tuck stitches exhibited the highest stitch density, fiber content, and the shortest loop length. This caused the lowest air permeability and the highest bursting strength. Contrary to expectations, weft-inlay yarn did not contribute to bursting strength as much as tuck stitch did. An overall negative correlation between air permeability and bursting strength was disrupted by structures with tuck stitches. While tuck stitches from cotton yarn increased air permeability and decreased bursting strength in previous studies; this study indicated that tuck stitches from glass yarn decreased air permeability and increased bursting strength.     

Impact of structural variations in hollow yarn on heat and moisture transport properties of fabrics

The use of hollow/microporous yarns plays an important role in enhancing the thermo‐physiological comfort properties of fabrics. Depending on structural variations in hollow yarn, heat and moisture regulation behaviours of fabrics can be affected significantly. In this study, three types of hollow cotton yarn fabrics, produced by introducing polyvinyl alcohol (PVA) filament in the core, PVA staple fibres in the blend and PVA filament in doubling with cotton spun yarn, are studied. All three types of pre‐hollow yarns and reference yarns are made with a variation in spinning technique (single roving/double roving) to prepare eight single jersey knitted fabrics. The hollow/microporous structure of the yarn is created by dissolving the PVA fibres using hot washing of the fabrics. On overall evaluation of the fabric’s thermo‐physiological comfort properties, the doubled hollow yarn fabrics are found to be better than other fabrics. In general, thermal resistance, thermal absorptivity, wicking and drying properties of all types of hollow yarn fabrics increase after repeated laundering, while air permeability, water vapour permeability and water absorbency of hollow yarn fabrics mostly decrease. In contrast with fabrics made from yarn produced through single roving technique, use of double roving technique only improves fabric water vapour permeability.     

Investigation of stretch on air permeability of knitted fabrics part II: effect of fabric structure

The structure of a fabric plays vital role in determining its air permeability. So, the study and comparison of air permeability of various fabric structures have their own significance. A detailed study is carried out here on various fabric structures to understand the effect of fabric structure on air permeability at their dry, wet and fully relaxed states. An automatic fabric stretching device has been designed and fabricated as an attachment with air permeability tester to test the air permeability of fabric samples under dynamic condition for this investigation. It is a fully automatic stretching equipment to stretch the fabric samples as per the preset value. The stretching device can be set with a predetermined degree of fabric stretch either in percentage or in mm and rate of extension also can be preset in mm per minute. From the results, it is clear that fabric structure has explicit impact on air permeability both in the unstretched and stretched states of the samples. Loose fabric structure and porous fabric structure show maximum air permeability under both sedate state and incrementally stretched states and vice versa.     

Effects of spandex drawing ratio and weave structure on the physical properties of cotton/spandex woven fabrics

In this experimental study, we investigated the effects of spandex filament drawing ratio and weave structures on the properties of cotton/spandex woven fabrics. One-way analysis of variance was used to explore the significant effects of the independent variables on the fabric properties. A regression analysis was also used to derive regression relationships between each of fabric properties and spandex filament drawing ratio. Our findings show that the spandex drawing ratio and structures of the woven fabrics significantly affect the physical and mechanical properties of the cotton/spandex woven fabrics. Cotton woven fabrics containing spandex show higher contraction, crease recovery, and flexural rigidity with increasing spandex drawing ratio, whereas the rest of fabric properties decreases with the increasing drawing ratio. Because of higher contraction and then higher weight, thickness, and cover factor of cotton/spandex fabrics, unexpected results of fabric air permeability and breaking elongation were detected.     

Comparative study of copper ion complex bamboo pulp and cotton knitted fabrics. Part I: copper ion contents and antibacterial performance

The paper mainly discusses the antibacterial performance of bamboo pulp and cotton fabrics which were treated with NaOH solution and copper ammonia solution. SEM, ICP-OES, and agar diffusion plate method were used to investigate the existence of copper ions and analyze the influence of treatment parameters on the copper ion content and antibacterial performance. The results show that there is significant difference for all the properties between bamboo pulp and cotton fabrics. The alkali treatment, concentration, and time period all have significant influence on the copper ion contents and antibacterial performance, and they have different influences on the bamboo pulp fabrics and cotton fabrics. The antibacterial performance not only depends on the copper ion content on the fabrics but also relate to the release action. The release ability of copper ions in bamboo fabrics is better than that in cotton fabrics. Alkali treatment makes the complex of copper ion more stable and the release rate slower.     

Taguchi approach for analyzing the impact of varying degrees of cotton stickiness. Part II: effect on rotor-spun yarn quality

In this paper, the effect of cotton stickiness and the effect of blending sticky with non-sticky cotton in quality of rotor-spun yarn and optimization of spinning process were studied using Taguchi experimental design technique which has recently emerged as a famous statistical approach and ANOVA. In the evaluations, analyses of the signal-to-noise ratio were used. Nine experiments were performed with respect to the L9 orthogonal design for the Taguchi approach. Taguchi Method was utilized to find the sequence of dominant factors contributing to rotor-spun yarn quality. The study revealed that the quality of rotor-spun yarn was not susceptible to stickiness and the dominant factor contributing to the most quality characteristics of rotor-spun yarn was the blending ratio. Results obtained by Taguchi method match closely with ANOVA.     

Role of filament cross-section in properties of PET multifilament yarn and fabric. Part I: Effect of fibre cross-sectional shape on transmission behaviour of fabrics

The transmission property of a fabric is a key factor that affects clothing’s comfort and decides the functional potential of clothing. The dependence of filament cross-section with varying shape factor (SF) on air, moisture and thermal transmission behaviour of fabric is determined in case of polyester multifilament woven fabrics. The linear density of each filament is kept identical for all 12 cross-section shape filaments. The SF of filament cross-section is an important factor which remained the prime factor to influence the transmission behaviour of fabric samples directly in many cases. Other indirect factors that influence the transmission behaviour of fabrics when the SF is identical are yarn structure, inter-fibre and inter-yarn space. Twelve different novel cross-sectional shapes are considered to make the multifilament woven polyester fabrics. The fabrics made from multifilament yarns having different SFs show that relative moisture vapour permeability and air permeability decrease with the rise in SF. Wickability increases with the rise in the SF of a filament cross-section. Multilobal, hexalobal and plus shapes were made a part of novel cross-sectional shapes in order to develop fabrics of higher comfort index.     

A study on siro-, solo-, compact-, and conventional ring-spun yarns. Part II: yarn strength with relation to physical and structural properties of yarns

The strength of siro-, solo-, compact-, and conventional ring-spun yarns has been examined with reference to yarn migration parameters, spinning-in-coefficient, number of broken fibers, and yarn hairiness. The measured results are presented in the forms of diagrams and tables. Results reveal that at various levels of gage length and strain rate, siro-spun yarns exhibit the highest tenacity, followed by compact-spun yarns, solo-spun yarns, and conventional ring-spun yarns. Analysis of the results demonstrate that the higher tenacity values of siro-spun yarns can be attributed to the higher mean fiber position, higher migration factor, greater proportion of broken fibers, and lower hairiness. It is also found that the strength of yarns to a considerable extent is governed by yarn structure, gage length, and strain rate.     

Role of filament cross-section in properties of PET multifilament yarn and fabric. Part II: effect of fibre cross-sectional shapes on fabric hand

To investigate the effect of fibre cross-sectional shape on hand of polyethylene terephthalate continuous multifilament fabrics, different fabric samples are developed with similar fabric areal density, weave, yarn and fibre linear density. The effect of fibre cross-sectional shape on various structure–property relationship of fabric is precisely characterized. Different cross-sectional shapes have different stiffness as well as different packing index with ideal geometry of filament yarns. The low-stress mechanical properties and hand behaviour of fabric are also altered by change in cross-sectional shape of filaments. The experimental results indicate that the alteration in cross-sectional shape can be a powerful tool for fabric engineering.