Low Temperature Dyeing Research Articles

A cost minimization process of heat and energy consumption for direct dyeing of cotton fabric coloration with triethanolamine

A cost minimization concept of heat and and energy consumption for direct dyeing process of cotton fabric coloration was experimented with triethanolamine instead of sodium carbonate in the dyebath of direct dyeing with low temperature at C medium temperature at Cand high temperature at Cand compared with the conventional method of direct dyeing with high temperature at Cwhere an acceptable range of increasing color strength K S and color difference were observed for low temperature dyeing with triethanolamine TEA method comparing to the conventional dyeing process of high temperature with sodium carbonate SC method Considering heat and energy consumption in direct dyeing of cotton fabric coloration with triethanolamine method the low temperature dyeing cost was minimized Rs comparing to high temperature sodium carbonate method dyeing cost

Ultrasonic scouring as a pretreatment of wool and its application in low-temperature dyeing

Ultrasonic technology has shown the potential to reduce the cost and environmental impact of textile wet processing. This work investigates the effects of ultrasonic irradiation as a pretreatment on wool and its application in low-temperature dyeing. A significant increase in dye uptake and color strength was observed on the fabric ultrasonically pretreated at 40 kHz, followed by that at 80 kHz and the conventionally treated sample, in both acid dyeing and reactive dyeing. This could be due to the changes of the fiber surface structure and modification of the chemical structure in the cell membrane complex as a result of ultrasonic pretreatment. In acid dyeing, a 20% increase in dye uptake was achieved at 70℃ upon applying ultrasonic pretreatment at 40 kHz. With the assistance of a leveling agent, 80% dye uptake of the fabric treated with ultrasonics at 40 kHz was measured at 70℃ in reactive dyeing. Ultrasonic pretreatment can be applied in raw wool scouring and fabric scouring to achieve an efficient dye uptake, and these are also discussed in this paper.

One-bath one-step low-temperature dyeing of polyester/cotton blended fabric with cationic dyes via β-cyclodextrin modification

With the aim of polyester/cotton fabric one-bath one-step dyeing, polyester fabric low-temperature dyeing with cationic dyes was investigated based on β-cyclodextrin (β-CD) modification. After β-CD/citric acid (CA) modification, the hydrophilicity of the modified polyester fabric was improved obviously, which was demonstrated via moisture regain and contact angle, as well as wicking property. The optimal dyeing temperature and crosslinking agent were selected through comparing the color strength of the dyed polyester fibers. Modified polyester fabric obtained significantly enhanced color strength from 0.12 to 4 with a good leveling property when dyeing at 70℃ using CA as the crosslinking agent. β-CD modified polyester/cotton fabric displayed a K/ S value of 8.61, much higher than the value of 0.71 of the unmodified fabric with cationic dyes, showing a highly improved dyeing ability. The color fastness of β-CD modified polyester/cotton fabrics, including washing fastness, rubbing fastness, perspiration fastness and light fastness, are all over grade 3–4 when the curing temperature of 180℃ is adopted for β-CD modification, demonstrating that polyester/cotton fabric one-bath one-step dyeing can be realized based on β-CD modification.

Effect of ultrasound on dyeing of wool fabric with acid dye

Wool fiber strength and handle is damaged by holding for prolonged periods at normal dyeing temperatures (98 °C). Lower dyeing temperatures can be employed to color wool whilst reducing damage caused to the fiber. However, these lower temperature dyeing processes often have a long dyeing time and/or require the addition of chemicals to achieve adequate dye exhaustion and migration. The use of ultrasonic irradiation was used to reduce dyeing times and temperatures whilst increasing dye migration and fastness. It has used 30 kHz frequency level, effective power of 120 and 350 W heating power in ultrasonic machine. In this work, wool dyeing was carried out on single jersey knitted fabric using an acid dye with and without ultrasonic irradiation at 60, 70, and 80 °C. Dye exhaustion was measured using UV/visible absorbance of the dye bath before and during the dyeing cycle. For the measurement of nodal/anti-nodal point of energy, at 60, 70, and 80 °C dyeing was done in open bath of ultrasonic machine with and without sonication at high liquor ratio. To compare the dye uptake (%) at high/conventional process, sample was dyed at 95 °C. Optical and scanning electron microscopy were used to measure the diameter and surface changes of the fiber, respectively. Wash and rub fastness was measured on the dyed fabrics after rinsing and drying. Ultrasonic irradiation during the dyeing of wool caused an increase in the dye exhaustion rate for acid dye. This change in rate is believed to have been caused by a reduction in the viscous boundary layer of liquor surrounding the fiber present in an ultrasonic irradiated environment. An increased dye migration due to cuticle cracking and fiber swelling was not deemed to have occurred as wet fiber diameter was not changed by submersion in the dye liquor in the presence of ultrasound and no surface cracking was evident in scanning electron microscopy images. Some cuticle structure changes occurred with turning up or ripping off of the cuticle tips evident. Both wash and rub fastness were improved for ultrasonically dyed fiber with dyeing temperatures of 70 and 80 °C being suitable for the low-temperature dyeing of wool.

Dyeability of recycled electrospun polyethylene terephthalate (PET) nanofibers: Kinetics and thermodynamic study

Herein, we report for the very first time dyeing of recycled polyethylene terephthalate (r-PET) electrospun nanofibers from waste bottles using two different disperse dyes i.e. C.I Disperse Blue 56 (DB-56) and C.I Disperse Red 167:1 (DR 167:1). Since PET exhibit greater mechanical strength and is abundant in occurrence, therefore it was selected for dyeing purpose. The thermodynamic, standard affinities and kinetic parameters were also evaluated for the very first time. The dyeing process was found endothermic in nature based on positive values of enthalpy. The standard affinity and diffusion coefficient of DB-56 towards r-PET were found greater than DR-167:1. The proposed r-PET nanofibers offer many advantages such as excellent color fastness, good mechanical strength, low processing temperature and minimum dyeing time compared to other conventional nanofibers.

Application of wool reactive dyes for hair coloration

In this study, the low temperature dyeing properties of wool reactive dyes were investigated for the feasibility study of hair coloration using wool-reactive dyes. The low temperature (30°C, 40°C) wool reactive dyeing properties were compared to the conventional temperature (80°C) wool reactive dyeing and their dyeing properties were compared with those at high temperature. The experiment results showed that the application of low temperature wool reactive dyeing to hair coloration is sufficiently feasible in terms of dyeability and shampooing fastness.

Effect of sonochemical scouring on the surface morphologies, mechanical properties, and dyeing abilities of wool fibres

Ultrasonics has the potential to reduce the cost and environmental impact of textile processing. This work investigates the effects of ultrasonic irradiation during wool scouring on fibre surface morphologies, fibre mechanical properties, and fibre dyeing abilities. A range of ultrasonic frequencies were used in the scouring bath to examine the forms of fibre cuticle damage. It is observed that wool fibres underwent ultrasonic irradiation at a low frequency have severe modifications of the fibre surface structure. Despite some visible disruptions to the fibre scale structure however, ultrasonic irradiation has shown a negligible impact on the fibre mechanical properties, especially bending abrasion resistance which depends largely on the fibre surface conditions, and is responsible for the handle and pilling propensity of the resultant fabrics. Dyeing abilities were investigated on wool samples using commercially available acid dye and reactive dye. It is found that ultrasonically scoured wool has a quicker dye uptake in the early stage of low temperature dyeing for both acid dye and reactive dye, than the conventionally scoured wool.

Indigo Dyeing of Mongolian Cashmere Fiber

Mongolian cashmere sliver, yarn, and fabric were dyed and bleached with a solution of ascorbic acid and iron sulfate at 70℃, and then dyed using natural indigo powder at the dyeing temperature of 25℃ to 90℃ for 15- 90 minutes using the IR dyeing machine. K/S values of bleached samples decreased significantly when dyed above 70℃ dyeing temperature for a longer dyeing time. Bleached cashmere fabric showed a greater loss of tensile strength than unbleached cashmere fabric, even when the samples were dyed at 40℃. With a higher dyeing temperature, yarns lost fullness, became thinner, and the pores between the yarns were enlarged. The xray diffraction pattern exhibited a prominent increase in crystallinity and the protein assay indicated a loss of protein in the bleached sample dyed at 90℃. Thinning of scales, fractured or raised tip of scales, and roughness on the entire surface of the fiber were also observed. The results indicate that bleaching and high temperature dyeing cause a serious damage to cashmere fibers. In addition, bleaching and high temperature dyeing cause significant fiber damage. Natural indigo dyeing using low temperature dyeing is recommended to produce blue color cashmere.

Carrier-Free and Low-Temperature Ultradeep Dyeing of Poly(ethylene terephthalate) Copolyester Modified with Sodium-5-sulfo-bis(hydroxyethyl)-isophthalate and 2-Methyl-1,3-propanediol

To obtain sufficient dyeability, dyeing of poly(ethylene terephthalate) fabrics must be performed at high temperature and high pressure or by using a no-eco-friendly carrier at atmospheric pressure, which implies large energy consumption and environmental contamination. In order to improve the sustainability of the dyeing process, a carrier-free and low-temperature dyeing procedure was developed for the poly(ethylene terephthalate) copolyester (MCDP) incorporated with sodium-5-sulfo-bis(hydroxyethyl)-isophthalate (SIP) and 2-methyl-1,3-propanediol (MPD). The results obtained from cationic dyeing at optimized conditions show an outstanding dye utilization (99.0%) with MCDP, which is much higher than that of the conventional SIP-modified copolyester. Meanwhile, the introduction of SIP and MPD contents ensures the large adsorption and fast diffusion of dye molecules into the amorphous region of fibers, allowing an efficient and deep disperse dyeing of polyester fabrics under atmosphere in the absence of carr...

Structure and dyeing properties of jade fibre

Purpose – Based on clarifying the structural difference between jade fibre and general polyester fibre, this paper aims to study the dyeing properties and dyeing adsorption mechanism of jade fibre with disperse dye and cationic dye. Design/methodology/approach – The chemical structure and microstructure of jade fibre were briefly explained comparing with ordinary polyester fibre. The dyeing rate curve and dyeing adsorption isotherm of disperse dyes and cationic dyes on jade fibre were, respectively, studied. The dyeing uptake, dyeing absorption mechanism, and the main dyeing process parameters were proposed. Findings – Jade fibre can be dyed with cationic dye and disperse dye. The suitable exhaust dyeing process is 110°C and 40 minutes for disperse dye, 100°C and 60 minutes for cationic dye. The dyeing uptake on jade fibre with both disperse dyes or cationic dyes is much higher than that on general polyester fibre and acrylic fibre, and the dyeing adsorption mechanism belongs to the combination of Langmuir and Nernst adsorption for disperse dyes and Langmuir adsorption for cationic dyes. Comparing with ordinary polyester fibre, jade fibre has the advantage of low temperature dyeing and reduced effluent, as is significant to energy-saving and emission reduction. Originality/value – Jade fibre is a new type of modified polyester fibre with the function of health protection and energy conservation. There are little technical data in the literature at present about the dyeing property of jade fibre.

Low temperature dyeing of wool fabric by acid dye after UV irradiation

The aim of the work was to improve wool’s dyeability using acid dye through a simple pretreatment with ultraviolet (UV) irradiation. Different radiation doses were investigated using both a laboratory UV lamp and a semi-industrial apparatus. UV-treated fabrics were characterized in terms of morphological, chemical and physical properties by SEM, FTIR-ATR spectra, water contact angle measurements, bursting and pilling test. The pre-treated samples were then dyed with an acid dye at different dyeing temperatures to compare the results with the untreated fabric. Final bath exhaustion reached, kinetic curves and colour measurements were evaluated. Moreover, the colour levelness of the dyeings obtained on fabrics with and without irradiation was assessed. Finally, dyeing fastness to washing and rubbing were determined according to ISO standard methods.

Study on Low-Temperature Dyeing of Cashmere Fiber

In order to save energy and decrease the damage of cashmere in dyeing processing, adding low-temperature dyeing auxiliary for cashmere dyeing is introduced in this paper. Some processing factors such as pH value, dyeing temperature and concentration of two different low-temperature dyeing auxiliaries are studied. The results show that the low-temperature auxiliary addition strategy successfully improved the mechanical properties of dyed cashmere, compared with the traditional cashmere dyeing method. The optimized conditions are shown as follows: 7g/L of low-temperature dyeing auxiliaries A (LTD-A) or 10g/L of low-temperature dyeing auxiliaries B (LTD-B), pH at 4, first dyeing for 15 min at 40 oC and then dyeing for 60 min at 80 oC.

Dyeing behavior of laser-treated polyester

Polyester fabric was pre-treated with laser, followed by dyeing. The experimental results revealed that the rate of dyeing was greatly increased but the final percentage of dye exhaustion at equilibrium did not show any significant change. Based on the thermodynamic parameter of dyeing, it was concluded that laser treatment could provide the possibility of developing a low temperature dyeing process. Morphological and thermal studies revealed that obvious surface structure changes occurred. In the morphological analysis, ripple-like structure was found after laser treatment. This ripple-like structure may have captured more dye particles which could improve the dyeing behavior of polyester fibre. On the other hand, thermal analysis result revealed that the surface of polyester becomes highly amorphous on laser treatment, due to ablation. Meanwhile, XPS analysis showed that hydrophilic functional groups were introduced on to the laser-treated polyester fibre surface. As a result, surface physical and chemical changes induced by laser affect the dyeing behavior of polyester fibre. However, the laser treatment could not impart any adverse effect on color fastness to crocking and washing.

A study of TiO2 binder-free paste prepared for low temperature dye sensitized solar cells – ERRATUM

A study of TiO2 binder-free paste prepared for low temperature dye sensitized solar cells – ERRATUM

Vanillin, a potential carrier for low temperature dyeing of polyester fabrics

The potential use of vanillin for the chemical substitution of toxic carriers used in low temperature dyeing of polyester fabrics, was assessed. Both para and ortho-vanillin were used to compare the dyeing of a woven polyester fabric with two different blue disperse dyes: a high molecular weight anthraquinone dye D79 and a low molecular weight azoic dye D56. When 1 g of vanillin was used for dyeing with 3% of disperse dye, the dye uptakes increased for both vanillins, but were higher with ortho-vanillin especially in the case of the low molecular weight dye. The impact of different dyeing parameters such as pH, o-vanillin concentration and use of ethanol co-solvent, on the dye uptake was also studied. Highest dye uptake was reached with 2 g of ortho-vanillin at pH 7, without use of the co-solvent. Dye uptakes were compared to those of traditional carriers such as phenylphenol, dichlorobenzene, benzoic acid, and a commercial Levegal DTE carrier. With 2 g of vanillin, K/S of dyed fabric reached 16, which is equivalent to that obtained with 1 g of the commercial carrier. The study confirms that vanillin can be used as a chemical substitute to traditional carriers and leads to good wash and rub fastness properties. At present, few literature data are available to compare toxicity of all carriers and apply the principle of substitution. A toxicity analysis carried out using USEtox™ model showed that both para and ortho vanillins used in agro-food industries are not recognized as toxic for human health, unlike most traditional carriers. Ortho-vanillin has however high ecotoxicity.

저융점 폴리에스테르 복합사의 저온 염색성

Abstract: Jacquard floor covering could be prepared from low-melting/regular sheath-core hybrid polyester, where the fiberis dyed in yarn state. With regard that the expected high shrinkage of the hybrid polyester in water makes problems in yarndyeing, low-temperature dyeing properties of the hybrid polyester were studied. The rate of shrinkage of low-melting hybridpolyester exceeds 9% in hot water above 90 , at such condition, cheese yarn dyeing is very difficult. Although disperse dyes℃exhaust in a relatively high speed on low-melting hybrid polyester, diffusion of these dyes to the core regular polyester wasextremely slow under 90 . Foron Blue E-BL 150, an anthraquinone E-type disperse dye, showed appreciable diffusion after℃48hrs dyeing at 90 . The fastness to rubbing and drycleaning were improved by one grade after reduction cleaning.℃ Keywords: low-melting polyester, sheath-core, dyeability, low-temperature dyeing, shrinkage, reduction cleaning 저융점폴리에스테르복합사의저온염색성 황지현 김창남· 1 · 마진숙

Influence of Low-Temperature Dyeing Process on Physical Properties and Surface Morphology of Cashmere Fibers

A low temperature dyeing process of cashmere has the advantages of saving energy and causing less damage to fibers. In this paper, the tensile properties of dyed cashmere by low-temperature dyeing and conventional dyeing were tested using a single fiber tensile tester. The surface morphologies of raw cashmere and dyed cashmere were observed by scanning electron microscopy (SEM). The SEM pictures show that the damage of the surface scale of cashmere by low the temperature dyeing process was much less than by the conventional dyeing process, and the tensile strength of deyed cashmere fiber by low-temperature dyeing was found to be high. Light-color and medium-color cashmere fibers dyed with Pula dye by low-temperature dyeing have good color fastness.

Influence of Low Temperature Dyeing Process on Physical and Mechanical Properties of Cashmere Knitwear

In this paper, cashmere knitwear is dyed at a lower temperature compared to conventional dyeing, and its physical and mechanical properties are analyzed and compared. The results show that cashmere knitwear dyed at low temperature can improve cashmere knitwear quality. It is also shown that cashmere knitwear dyed at low temperature can have improved physical and mechanical properties, especially its strength, abrasion resistance and pilling resistance.

Effect of atmospheric pressure helium plasma on felting and low temperature dyeing of wool

AbstractWool fabrics were treated with atmospheric pressure helium glow discharge plasma in an attempt to improve felting and dyeing behavior with cold brand reactive dyes using cold pad‐batch method at neutral pH. On glow plasma treatment, the hydrophilicity of wool surface and its resistance toward felting was greatly improved without any significant damage to the cuticle layer. The color strength of the plasma treated dyed wool on the surface (in terms of K/S) was found to be nearly double of the color strength of dyed untreated wool fabric. However, the corresponding total dye uptake of the treated wool increased by a much lower value of 40%–50%. The reason behind this altered dyeing behavior was investigated by studying the dye kinetics using infinite bath and surface characteristics using SEM and SIMS. It was found that the glow plasma treatment greatly transformed the chemical surface of the wool fibers. It resulted in uniform removal of hydrophobic cuticular layer, which resulted in better diffusion of the dye molecules into the fiber, and formation of hydrophilic NH2 groups near the surface, which helped in anchoring the dye molecules close to the surface giving higher color strength than expected. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Ultrasound for low temperature dyeing of wool with acid dye

The possibility of reducing the temperature of conventional wool dyeing with an acid levelling dye using ultrasound was studied in order to reach exhaustion values comparable to those obtained with the standard procedure at 98 °C, obtaining dyed samples of good quality. The aim was to develop a laboratory method that could be transferred at industrial level, reducing both the energy consumption and fiber damage caused by the prolonged exposure to high temperature without the use of polluting auxiliary agents. Dyeings of wool fabrics were carried out in the temperature range between 60 °C and 80 °C using either mechanical or ultrasound agitation of the bath and coupling the two methods to compare the results. For each dyeing, the exhaustion curves of the dye bath were determined and the better results of dyeing kinetics were obtained with ultrasound coupled with mechanical stirring. Hence the corresponding half dyeing times, absorption rate constants according to Cegarra–Puente modified equation and ultrasonic efficiency were calculated in comparison with mechanical stirring alone. In the presence of ultrasound the absorption rate constants increased by at least 50%, at each temperature, confirming the synergic effect of sonication on the dyeing kinetics. Moreover the apparent activation energies were also evaluated and the positive effect of ultrasound was ascribed to the pre-exponential factor of the Arrhenius equation. It was also shown that the effect of ultrasound at 60 °C was just on the dye bath, practically unaffecting the wool fiber surface, as confirmed by the results of SEM analysis. Finally, fastness tests to rubbing and domestic laundering yielded good values for samples dyed in ultrasound assisted process even at the lower temperature. These results suggest the possibility, thanks to the use of ultrasound, to obtain a well equalized dyeing on wool working yet at 60 °C, a temperature process strongly lower than 98 °C, currently used in industry, which damages the mechanical properties of the fibers.