Indians have been considered as forerunners in the art of natural dyeing. Although indigenous knowledge system has been practiced over the years in the past, the use of natural dyes has diminished over generations due...Indians have been considered as forerunners in the art of natural dyeing. Although indigenous knowledge system has been practiced over the years in the past, the use of natural dyes has diminished over generations due to lack of documentation and precise knowledge of the extracting and dyeing techniques. As a result, natural dyes are not commercially successful. Presently, all environmentally unfriendly synthetic compounds are used for dyeing textile materials. They are non-biodegradable, carcinogenic and generate water pollution as well as waste disposal problems. Natural dyes provide a reasonable solution to these problems. Thus, it is imperative to develop technology for extraction of natural dyes and for their application on textile materials. In this study, attempt has been made to extract natural dyes from a variety of plants sources (such as rhizomes of turmeric, Curcuma longa;fruits of harda, Terminalia chebula;petals of safflower, Carthamus tinctorius;roots of barberry, Berberis lycium etc.) using specific techniques. These dyes were tested for their dyeing potential on different textile materials (cotton, silk and wool). Dyeing was done using three different dyeing techniques (pre-, simultaneous- and post-mordanting) wherein different mordants such as alum, copper sulphate and ferrous sulphate etc., were used to fix dye on to the textile material. A rainbow of natural dyes was obtained with varied shades of each colour. Shade cards were prepared for each dye and the colour obtained varied depending on the type of the mordant applied and the mordanting technique used.展开更多
Batches experiments were carried out to study the removal potentials of Moringa oleifera seed presscake( MOSP),the residual solids of Moringa oleifera seed after oil extraction used as a natural coagulant for the remo...Batches experiments were carried out to study the removal potentials of Moringa oleifera seed presscake( MOSP),the residual solids of Moringa oleifera seed after oil extraction used as a natural coagulant for the removal of two direct azo dyes including Direct Red-31( DR-31) and Direct Yellow-12( DY-12). The results indicated that the MOSP contained active proteins which were active agents and efficient for the removal of the two dyes. Higher temperature and lower p H were favorable for dye removal. The removal rates of the two dyes increased with the increasing MOSP dosage. Inorganic salts improved the dye removal efficiencies by the salt-in effect that prompted the release of proteins from the MOSP particles. Suspended solid simulated by kaolin decreased the dye removal efficiencies because of the competition for active sites of the MOSP between the kaolin particles and the dye molecules. The most likely mechanism for the removal of the two dyes by using MOSP as coagulant was a combined effect of adsorption and neutralisation of charges and the nucleation of the MOSP particles. The results provide new insight into the MOSP utilization and development of new coagulant for dye removal.展开更多
The degradation and decolourization of direct dye(Everdirect supra turguoise blue,FBL),acidic dye(Isolan orange S-RL) and vat dye(Indanthren red FBB) have been investigated by solar/TiO2 process.The effects of solutio...The degradation and decolourization of direct dye(Everdirect supra turguoise blue,FBL),acidic dye(Isolan orange S-RL) and vat dye(Indanthren red FBB) have been investigated by solar/TiO2 process.The effects of solution pH,dye concentration,dosage of TiO2 and nano-size of TiO2 have been studied.The increase in initial pH(3,5 and 11) and dye concentration decrease the removal rate.The treatment for FBB and FBL dye solutions is more efficient than that of S-RL.Under optimum conditions,the color removal is found to be almost complete for FBB and FBL while that of S-RL also reaches 95%.Langmuir adsorption isotherm and modified Langmuir-Hinshelwood kinetic model(L-H model) have been fitted to the experimental data and found to correlate the adsorption patterns as well as the kinetics of the dyes studied.展开更多
This work focused on effects of an eco-friendly carrier JYK on thermal properties,dye uptake,color yield(K/S values)and color fastness of recycled polyester knit fabrics.The study also explored optimization of the low...This work focused on effects of an eco-friendly carrier JYK on thermal properties,dye uptake,color yield(K/S values)and color fastness of recycled polyester knit fabrics.The study also explored optimization of the low-temperature carrier(LTC)dyeing and compared its dyeing performance to the high-temperature and high-pressure(HTHP)dyeing.Results showed that the eco-friendly carrier JYK had an obvious plasticizing effect on recycled polyester,which significantly reduced the glass transition temperature,thereby reducing the dyeing temperature and benefiting low-temperature dyeing.The optimal dyeing conditions were determined as follows:the disperse dye was 2%on weight of fabric(owf)and the eco-friendly carrier JYK was 2%owf at 98℃dyeing temperature for 60 min.Compared with the HTHP dyeing,there was no significant difference in the K/S values and color fastness of recycled polyester fabrics dyed in the low-temperature method which demonstrated that the low-temperature method could be totally accepted.This study indicated that the low-temperature dyeing with a carrier JYK could be an effective and sustainable method for dyeing recycled polyester.展开更多
Two direct dyes were applied to conventional viscose(CV)and bamboo viscose(BV)fibers,which were prepared from bamboo cellulose pulps,and the dyeing kinetics of two fibers were compared.Three kinetic equations,namely C...Two direct dyes were applied to conventional viscose(CV)and bamboo viscose(BV)fibers,which were prepared from bamboo cellulose pulps,and the dyeing kinetics of two fibers were compared.Three kinetic equations,namely Chrastil,Cegarra-Puente,and Vickerstaff,were used to fit the experimental dyeing rate points,showing that the best result was obtained by the Chrastil equation.BV fibers displayed slightly higher dyeing rates and dye adsorption values at initial stages,but a bit lower dye adsorption values at equilibrium than CV fibers.Furthermore,the dyeing of BV fibers exhibited lower activation energies and higher dyeing rate constants than that of CV fibers,and therefore showed slightly lower dependence on temperature.展开更多
Throughout the supply chain,there is interest in conserving resources and reducing the textile industry's environmental footprint.Every stage of a textile product's life cycle has environmental impacts-from fi...Throughout the supply chain,there is interest in conserving resources and reducing the textile industry's environmental footprint.Every stage of a textile product's life cycle has environmental impacts-from fiber production through manufacturing and retailing to laundering and disposal by consumers.Of particular concern is the use of water,energy,and chemicals(WEC) in textile processing-an area where technological advances offer significant savings in resources and environmental benefits.In cotton textile processing, dyeing and finishing have the largest WEC requirements and therefore offer the greatest scope for reductions.展开更多
文摘Indians have been considered as forerunners in the art of natural dyeing. Although indigenous knowledge system has been practiced over the years in the past, the use of natural dyes has diminished over generations due to lack of documentation and precise knowledge of the extracting and dyeing techniques. As a result, natural dyes are not commercially successful. Presently, all environmentally unfriendly synthetic compounds are used for dyeing textile materials. They are non-biodegradable, carcinogenic and generate water pollution as well as waste disposal problems. Natural dyes provide a reasonable solution to these problems. Thus, it is imperative to develop technology for extraction of natural dyes and for their application on textile materials. In this study, attempt has been made to extract natural dyes from a variety of plants sources (such as rhizomes of turmeric, Curcuma longa;fruits of harda, Terminalia chebula;petals of safflower, Carthamus tinctorius;roots of barberry, Berberis lycium etc.) using specific techniques. These dyes were tested for their dyeing potential on different textile materials (cotton, silk and wool). Dyeing was done using three different dyeing techniques (pre-, simultaneous- and post-mordanting) wherein different mordants such as alum, copper sulphate and ferrous sulphate etc., were used to fix dye on to the textile material. A rainbow of natural dyes was obtained with varied shades of each colour. Shade cards were prepared for each dye and the colour obtained varied depending on the type of the mordant applied and the mordanting technique used.
基金the Research and Demonstration of Key Technology of Pollution Control for Heavily Polluting Industries in the Upper and Middle Reaches of Shaying River,China(No.2009ZX07210-002)The Opening Fund of State Key Laboratory of Pollution Control&Resource Reuse of Nanjing University,China(No.PCRRF12016)
文摘Batches experiments were carried out to study the removal potentials of Moringa oleifera seed presscake( MOSP),the residual solids of Moringa oleifera seed after oil extraction used as a natural coagulant for the removal of two direct azo dyes including Direct Red-31( DR-31) and Direct Yellow-12( DY-12). The results indicated that the MOSP contained active proteins which were active agents and efficient for the removal of the two dyes. Higher temperature and lower p H were favorable for dye removal. The removal rates of the two dyes increased with the increasing MOSP dosage. Inorganic salts improved the dye removal efficiencies by the salt-in effect that prompted the release of proteins from the MOSP particles. Suspended solid simulated by kaolin decreased the dye removal efficiencies because of the competition for active sites of the MOSP between the kaolin particles and the dye molecules. The most likely mechanism for the removal of the two dyes by using MOSP as coagulant was a combined effect of adsorption and neutralisation of charges and the nucleation of the MOSP particles. The results provide new insight into the MOSP utilization and development of new coagulant for dye removal.
文摘The degradation and decolourization of direct dye(Everdirect supra turguoise blue,FBL),acidic dye(Isolan orange S-RL) and vat dye(Indanthren red FBB) have been investigated by solar/TiO2 process.The effects of solution pH,dye concentration,dosage of TiO2 and nano-size of TiO2 have been studied.The increase in initial pH(3,5 and 11) and dye concentration decrease the removal rate.The treatment for FBB and FBL dye solutions is more efficient than that of S-RL.Under optimum conditions,the color removal is found to be almost complete for FBB and FBL while that of S-RL also reaches 95%.Langmuir adsorption isotherm and modified Langmuir-Hinshelwood kinetic model(L-H model) have been fitted to the experimental data and found to correlate the adsorption patterns as well as the kinetics of the dyes studied.
基金National Key Research and Development Program of China(No.2016YFB0302900)。
文摘This work focused on effects of an eco-friendly carrier JYK on thermal properties,dye uptake,color yield(K/S values)and color fastness of recycled polyester knit fabrics.The study also explored optimization of the low-temperature carrier(LTC)dyeing and compared its dyeing performance to the high-temperature and high-pressure(HTHP)dyeing.Results showed that the eco-friendly carrier JYK had an obvious plasticizing effect on recycled polyester,which significantly reduced the glass transition temperature,thereby reducing the dyeing temperature and benefiting low-temperature dyeing.The optimal dyeing conditions were determined as follows:the disperse dye was 2%on weight of fabric(owf)and the eco-friendly carrier JYK was 2%owf at 98℃dyeing temperature for 60 min.Compared with the HTHP dyeing,there was no significant difference in the K/S values and color fastness of recycled polyester fabrics dyed in the low-temperature method which demonstrated that the low-temperature method could be totally accepted.This study indicated that the low-temperature dyeing with a carrier JYK could be an effective and sustainable method for dyeing recycled polyester.
基金National Key Technology R&D Program of the Chinese Ministry of Science and Technology,China(No.2007BAE41B04)
文摘Two direct dyes were applied to conventional viscose(CV)and bamboo viscose(BV)fibers,which were prepared from bamboo cellulose pulps,and the dyeing kinetics of two fibers were compared.Three kinetic equations,namely Chrastil,Cegarra-Puente,and Vickerstaff,were used to fit the experimental dyeing rate points,showing that the best result was obtained by the Chrastil equation.BV fibers displayed slightly higher dyeing rates and dye adsorption values at initial stages,but a bit lower dye adsorption values at equilibrium than CV fibers.Furthermore,the dyeing of BV fibers exhibited lower activation energies and higher dyeing rate constants than that of CV fibers,and therefore showed slightly lower dependence on temperature.
文摘Throughout the supply chain,there is interest in conserving resources and reducing the textile industry's environmental footprint.Every stage of a textile product's life cycle has environmental impacts-from fiber production through manufacturing and retailing to laundering and disposal by consumers.Of particular concern is the use of water,energy,and chemicals(WEC) in textile processing-an area where technological advances offer significant savings in resources and environmental benefits.In cotton textile processing, dyeing and finishing have the largest WEC requirements and therefore offer the greatest scope for reductions.
