The Experts below are selected from a list of 4644 Experts worldwide ranked by ideXlab platform
Meetal Bhagvandas - One of the best experts on this subject based on the ideXlab platform.
-
sustainable ultrasound assisted ultralow Liquor Ratio dyeing of wool textiles with an acid dye
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Mohammad M. Hassan, Meetal BhagvandasAbstract:Conventional wool dyeing is an energy-hungry process as the dyeing is carried out at boil using a high Liquor Ratio. It can be energy efficient if dyeing can be carried out at low temperatures or if the Liquor Ratio can be reduced. Ultralow Liquor Ratio dyeing (materials to Liquor Ratio of 1:5) is advantageous as it considerably reduces consumption of auxiliary chemicals and energy in dyeing. However, at that low Liquor Ratio dye molecules form agglomerates causing low dye-uptake and uneven dying. In this work, the feasibility of using ultrasound in conjunction with a range of textile auxiliaries for the prevention from dye agglomeRation has been investigated for the dyeing of wool with an acid dye. Three ultrasonic baths with different ultrasonic power were used to investigate the effect of ultrasonic power on dyeing performance. It was found that citric acid in conjunction with ultrasound prevented the formation of dye agglomeRation in a dyebath and also produced deeper shades and uniform dyeings compar...
-
Sustainable low Liquor Ratio dyeing of wool with acid dyes: Effect of auxiliaries on agglomeRation of dye molecules in a dyebath and dyeing uniformity
Journal of Cleaner Production, 2017Co-Authors: Mohammad M. Hassan, Meetal BhagvandasAbstract:The use of a low-Liquor Ratio (1:10 or less) in the dyeing of wool has several economic and environmental benefits, such as lower energy usage and smaller quantity of auxiliaries are required compared to the traditional dyeing method. However, the reduction in Liquor Ratio increases the occurrence of agglomeRation of dyes causing uneven dyeing. The aim of this study is to develop a low-Liquor dyeing method for wool with acid dyes that could potentially be applied to larger scale industrial practices. In this work, the feasibility of application of several chemical auxiliaries to prevent the agglomeRation of dyes in dyebaths and also for improving the dyeing uniformity in the low Liquor Ratio dyeing of wool fabric with three acid dyes, has been investigated. Optical microscopy was used to evaluate the performance of various auxiliaries to prevent the agglomeRation of dyes in a dyebath. The dyeing uniformity was assessed by measuring the colour difference in various parts of the same dyed fabric by a hand-held reflectance spectrophotometer. It was found that Teric G12A6 showed the best results in terms of prevention from the agglomeRation of dyes and the dyeing uniformity produced for all three acid dyes investigated. The low Liquor Ratio dyeing of wool fabrics with acid dyes using Teric G12A6 as a dye agglomeRation preventer is equally efficient as the traditional high Liquor Ratio dyeing in terms of colour strength and uniformity in dyeing. The developed method could reduce dyeing cost and environmental footprint compared to the traditional dyeing of wool.
Mohammad M. Hassan - One of the best experts on this subject based on the ideXlab platform.
-
sustainable ultrasound assisted ultralow Liquor Ratio dyeing of wool textiles with an acid dye
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Mohammad M. Hassan, Meetal BhagvandasAbstract:Conventional wool dyeing is an energy-hungry process as the dyeing is carried out at boil using a high Liquor Ratio. It can be energy efficient if dyeing can be carried out at low temperatures or if the Liquor Ratio can be reduced. Ultralow Liquor Ratio dyeing (materials to Liquor Ratio of 1:5) is advantageous as it considerably reduces consumption of auxiliary chemicals and energy in dyeing. However, at that low Liquor Ratio dye molecules form agglomerates causing low dye-uptake and uneven dying. In this work, the feasibility of using ultrasound in conjunction with a range of textile auxiliaries for the prevention from dye agglomeRation has been investigated for the dyeing of wool with an acid dye. Three ultrasonic baths with different ultrasonic power were used to investigate the effect of ultrasonic power on dyeing performance. It was found that citric acid in conjunction with ultrasound prevented the formation of dye agglomeRation in a dyebath and also produced deeper shades and uniform dyeings compar...
-
Sustainable low Liquor Ratio dyeing of wool with acid dyes: Effect of auxiliaries on agglomeRation of dye molecules in a dyebath and dyeing uniformity
Journal of Cleaner Production, 2017Co-Authors: Mohammad M. Hassan, Meetal BhagvandasAbstract:The use of a low-Liquor Ratio (1:10 or less) in the dyeing of wool has several economic and environmental benefits, such as lower energy usage and smaller quantity of auxiliaries are required compared to the traditional dyeing method. However, the reduction in Liquor Ratio increases the occurrence of agglomeRation of dyes causing uneven dyeing. The aim of this study is to develop a low-Liquor dyeing method for wool with acid dyes that could potentially be applied to larger scale industrial practices. In this work, the feasibility of application of several chemical auxiliaries to prevent the agglomeRation of dyes in dyebaths and also for improving the dyeing uniformity in the low Liquor Ratio dyeing of wool fabric with three acid dyes, has been investigated. Optical microscopy was used to evaluate the performance of various auxiliaries to prevent the agglomeRation of dyes in a dyebath. The dyeing uniformity was assessed by measuring the colour difference in various parts of the same dyed fabric by a hand-held reflectance spectrophotometer. It was found that Teric G12A6 showed the best results in terms of prevention from the agglomeRation of dyes and the dyeing uniformity produced for all three acid dyes investigated. The low Liquor Ratio dyeing of wool fabrics with acid dyes using Teric G12A6 as a dye agglomeRation preventer is equally efficient as the traditional high Liquor Ratio dyeing in terms of colour strength and uniformity in dyeing. The developed method could reduce dyeing cost and environmental footprint compared to the traditional dyeing of wool.
Sm Burkinshaw - One of the best experts on this subject based on the ideXlab platform.
-
The role of auxiliaries in the immersion dyeing of textile fibres: Part 4 theoretical model to describe the role of Liquor Ratio in dyeing cellulosic fibres with direct dyes in the absence and presence of inorganic electrolyte
'Elsevier BV', 2019Co-Authors: Sm Burkinshaw, Salihu GAbstract:A model is proposed to explain the manner by which the uptake of direct dyes on cellulosic fibres is promoted by a reduction in the Liquor Ratio used for dyeing. According to the model, which invokes the concept of interstitial water in dyeing, reducing the Liquor Ratio promotes dye aggregation which reduces the solubility of the dye in the bulk dyebath phase, so that the inherent preference of the dye to favour the aqueous phase shifts towards the fibre phase. It is suggested that the same mechanism accounts for the promotion of direct dye uptake imparted by the addition of inorganic electrolyte to direct dye dyebaths. As such, reduced Liquor Ratio and added inorganic electrolyte exert a combinatorial promotional effect on direct dye uptake
-
The role of auxiliaries in the immersion dyeing of textile fibres: Part 5 practical aspects of the role of inorganic electrolytes in dyeing cellulosic fibres with direct dyes
Dyes and Pigments, 2019Co-Authors: Sm Burkinshaw, George SalihuAbstract:Both the colour strength of 2% omf dyeings and the extent of dye exhaustion achieved for three commercial grade direct dyes on cotton were promoted by the addition of 20 gl−1 NaCl at each of eight Liquor Ratios (1:50, 1:20, 1:10, 1:6, 1:3, 1:2, 1:1.5 and 1:1). The extent of electrolyte-enhanced dye uptake decreased with decreasing Liquor Ratio. For each of the three dyes, unlevel dyeings were obtained at 1:1 Liquor Ratio only in the presence of added electrolyte, whereas level dyeings were secured even at 1:1 Liquor Ratio in the complete absence of added electrolyte. The depth of the dyeings obtained in the absence of added electrolyte using both 1:1 and 1:1.5 Liquor Ratios were of similar magnitude to those secured using 1:10, 1:20 and 1:50 Liquor Ratios in the presence of 20 gl−1 NaCl. The promotion of dye uptake imparted by both added electrolyte and reduced Liquor Ratio were interpreted in terms of their effects on the substantivity of the direct dyes towards the cotton substrate. It is proposed that adding electrolyte to the dyebath and reducing the Liquor Ratio employed for dyeing have the same consequence in terms of enhancing dye uptake, namely that of encouraging dye aggregation in the dyebath which reduces the aqueous solubility of the anionic dye, which, in turn, results in the inherent preference of the dye to favour the aqueous phase shifting towards the fibre phase.
-
The role of auxiliaries in the immersion dyeing of textile fibres: Part 8 practical aspects of the role of inorganic electrolytes in dyeing cellulosic fibres with commercial reactive dyes
Dyes and Pigments, 2019Co-Authors: Sm Burkinshaw, George SalihuAbstract:The colour strength of 2% omf dyeings, as well as the extents of both exhaustion and fixation, achieved for three commercial grade reactive dyes on cotton, were promoted by the addition of 50 gl-1 NaCl at each of seven Liquor Ratios (1:50, 1:20, 1:10, 1:6, 1:3, 1:2 and 1:1.5). The depth of shade of dyeings obtained in the absence of added electrolyte using a 1:1.5 Liquor Ratio were of similar magnitude to those secured using a 1:10 Liquor Ratio in the presence of 50 gl-1 NaCl. The promotion of dye uptake imparted by both added electrolyte and reduced Liquor Ratio was interpreted in terms of their effects on the substantivity of the reactive dyes towards the cotton substrate. It was concluded that the two, ostensibly different actions of adding electrolyte such as NaCl or Na2SO4 to a reactive dye dyebath and reducing the Liquor Ratio used for dyeing have the same result, namely that of promoting dye aggregation in the dyebath which reduces the aqueous solubility of the anionic dye, which, in turn, results in the inherent preference of the dye to favour the aqueous phase shifting towards the fibre phase. The results show that it is possible to dye cotton using commercial grade reactive dyes in the complete (ie 100%) absence of added inorganic electrolyte. The dyeings obtained were of realistic depths of shade and displayed excellent levels of wash fastness.
-
The role of auxiliaries in the immersion dyeing of textile fibres: Part 7 theoretical models to describe the mechanism by which inorganic electrolytes promote reactive dye uptake on cellulosic fibres
'Elsevier BV', 2019Co-Authors: Sm Burkinshaw, Salihu GAbstract:A model is proposed to explain the manner by which the uptake of reactive dyes on cellulosic fibres is promoted by the addition of NaCl or Na2SO4 to the dyebath. The theoretical model invokes the concept of interstitial water in dyeing and suggest that increased dye uptake occurs because the added inorganic electrolyte promotes dye aggregation which reduces the solubility of the dye in the dyebath, so that the inherent preference of the highly soluble dye to favour the aqueous phase shifts towards the fibre phase. It is proposed that the same model can account for the promotion of direct dye uptake imparted by the reduction in the Liquor Ratio utilised for dyeing. As such, added inorganic electrolyte and reduced Liquor Ratio are considered to exert a combinatorial promotional effect on reactive dye uptake
-
The role of auxiliaries in the immersion dyeing of textile fibres: Part 9 practical aspects of the role of inorganic electrolytes in dyeing cellulosic fibres with pure reactive dyes
'Elsevier BV', 2019Co-Authors: Sm Burkinshaw, Salihu GAbstract:The colour strength, as well as the extents of both exhaustion and fixation, achieved for three pure reactive dyes on cotton were promoted by the addition of 50 gl⁻¹ NaCl at each of seven Liquor Ratios employed (1:50, 1:20, 1:10, 1:6, 1:3, 1:2 and 1:1.5). The depth of shade of dyeings obtained in the absence of added electrolyte using a1:1.5 Liquor Ratio were of similar magnitude to those secured using 1:10–1:20 Liquor Ratios in the presence of 50 gl⁻¹ NaCl. The promotional effect on dye uptake imparted by both added electrolyte and reduced Liquor Ratio was interpreted in terms of their effects on the substantivity of the reactive dyes towards the cotton substrate. The two, seemingly different actions of adding electrolyte such as NaCl or Na₂SO₄ to the reactive dye dyebath and reducing the Liquor Ratio used for immersion dyeing have the same result, namely that of encouraging dye aggregation in the dyebath, which reduces the solubility of the direct dye in the dyebath, which, in turn, shifts the inherent preference of the dye to favour the aqueous phase towards the fibre phase. It is thus possible to dye cotton using pure reactive dyes in the complete (ie 100%) absence of added inorganic electrolyte. The ensuing dyeings were of realistic depths of shade and displayed excellent levels of wash fastness
George Salihu - One of the best experts on this subject based on the ideXlab platform.
-
The role of auxiliaries in the immersion dyeing of textile fibres: Part 8 practical aspects of the role of inorganic electrolytes in dyeing cellulosic fibres with commercial reactive dyes
Dyes and Pigments, 2019Co-Authors: Sm Burkinshaw, George SalihuAbstract:The colour strength of 2% omf dyeings, as well as the extents of both exhaustion and fixation, achieved for three commercial grade reactive dyes on cotton, were promoted by the addition of 50 gl-1 NaCl at each of seven Liquor Ratios (1:50, 1:20, 1:10, 1:6, 1:3, 1:2 and 1:1.5). The depth of shade of dyeings obtained in the absence of added electrolyte using a 1:1.5 Liquor Ratio were of similar magnitude to those secured using a 1:10 Liquor Ratio in the presence of 50 gl-1 NaCl. The promotion of dye uptake imparted by both added electrolyte and reduced Liquor Ratio was interpreted in terms of their effects on the substantivity of the reactive dyes towards the cotton substrate. It was concluded that the two, ostensibly different actions of adding electrolyte such as NaCl or Na2SO4 to a reactive dye dyebath and reducing the Liquor Ratio used for dyeing have the same result, namely that of promoting dye aggregation in the dyebath which reduces the aqueous solubility of the anionic dye, which, in turn, results in the inherent preference of the dye to favour the aqueous phase shifting towards the fibre phase. The results show that it is possible to dye cotton using commercial grade reactive dyes in the complete (ie 100%) absence of added inorganic electrolyte. The dyeings obtained were of realistic depths of shade and displayed excellent levels of wash fastness.
-
The role of auxiliaries in the immersion dyeing of textile fibres: Part 5 practical aspects of the role of inorganic electrolytes in dyeing cellulosic fibres with direct dyes
Dyes and Pigments, 2019Co-Authors: Sm Burkinshaw, George SalihuAbstract:Both the colour strength of 2% omf dyeings and the extent of dye exhaustion achieved for three commercial grade direct dyes on cotton were promoted by the addition of 20 gl−1 NaCl at each of eight Liquor Ratios (1:50, 1:20, 1:10, 1:6, 1:3, 1:2, 1:1.5 and 1:1). The extent of electrolyte-enhanced dye uptake decreased with decreasing Liquor Ratio. For each of the three dyes, unlevel dyeings were obtained at 1:1 Liquor Ratio only in the presence of added electrolyte, whereas level dyeings were secured even at 1:1 Liquor Ratio in the complete absence of added electrolyte. The depth of the dyeings obtained in the absence of added electrolyte using both 1:1 and 1:1.5 Liquor Ratios were of similar magnitude to those secured using 1:10, 1:20 and 1:50 Liquor Ratios in the presence of 20 gl−1 NaCl. The promotion of dye uptake imparted by both added electrolyte and reduced Liquor Ratio were interpreted in terms of their effects on the substantivity of the direct dyes towards the cotton substrate. It is proposed that adding electrolyte to the dyebath and reducing the Liquor Ratio employed for dyeing have the same consequence in terms of enhancing dye uptake, namely that of encouraging dye aggregation in the dyebath which reduces the aqueous solubility of the anionic dye, which, in turn, results in the inherent preference of the dye to favour the aqueous phase shifting towards the fibre phase.
-
The role of auxiliaries in the immersion dyeing of textile fibres: Part 10 the influence of inorganic electrolyte on the wash-off of reactive dyes
Dyes and Pigments, 2018Co-Authors: Sm Burkinshaw, George SalihuAbstract:Abstract The depth of shade of dyeings obtained using three commercial reactive dyes on cotton in the absence of added electrolyte at a 1:2 Liquor Ratio were of similar magnitude to those secured in the presence of 50 gl-1 NaCl at a 1:10 Liquor Ratio. In the case of both the 2% omf (on mass of fibre) and 5% omf dyeings which had been produced in the complete absence of added inorganic electrolyte at low Liquor Ratio, substantially modified wash-off processes could be used that required ≥50% fewer wash baths than conventional wash-off processes that must be used in the case of dyeings produced in the presence of added inorganic electrolyte. Use of the modified wash-off processes enables substantial savings in both energy and water compared to their conventional wash-off counterparts; a 50% saving in proprietary wash-off agent was also secured when a 1:5 Liquor Ratio was employed for the modified wash-off processes. The ensuing electrolyte-free dyeings displayed excellent levels of wash fastness that were characteristic of those exhibited by commercial reactive dyes on cotton and other cellulosic fibres.
Muhammad Sufyan - One of the best experts on this subject based on the ideXlab platform.
-
Novel, sustainable and water efficient nano bubble dyeing of cotton fabric
Cellulose, 2020Co-Authors: Muhammad Mohsin, Shaheen Sardar, Muhammad Hassan, Nusrullah Akhtar, Ahmad Hassan, Muhammad SufyanAbstract:Textile is one of the basic human needs and almost all the textile fabrics are colored. Unfortunately, the extensive amounts of clean water, petrochemical based dyes, and chemicals are used for textile dyeing. After dyeing, these substances are discharged as pollutants. The disposal of this discharge is a serious issue which pollutes the natural environment. Therefore, there is a dire need to develop the novel dyeing processes with extremely low consumptions of water, dyes and chemicals. Nevertheless, the technologies with the low Liquor Ratios bring several challenges such as uneven dyeing, poor fastness, limited colors, lack of skills, and complicated processes. To address such challenges, this research achieves the extremely low Liquor Ratio of 1:1 using nano bubble technology. For the first time, this research describes novel, sustainable, and water efficient nano bubble dyeing of cotton with 11 different reactive dyes. The fabric dyeing performance properties of shade depth, dry rubbing fastness, wet rubbing fastness, and washing fastness were assessed for the Liquor Ratio of 1:1. The performance of 1:1 dyeing was compared with the conventional dyeing having Liquor Ratios of 1:5 and 1:10 for the same dyes. All the 11 reactive dyes, dyed at Liquor Ratio of 1:1 exhibited the uniform dyeing, acceptable fastness properties, and superior air permeability along with zero liquid discharge in the main dyeing cycle. Therefore, this research confirms the effectiveness of the newly developed dyeing process at extremely low Liquor Ratio of 1:1 for reactive cotton dyeing with significant saving of water, energy, dyes, chemicals and effluent load.