The effect of dispersing agents on the dyeing of polyester with a disperse dye

An experimental procedure has been devised to study the interdependence of three dispersing agents present in the dyeing of polyester with CI Disperse Orange 21. The method involves the use of ternary diagrams to represent the relationship between dyeing properties and the concentration of dispersing agents present in a dyebath. The technique could be applied to commercial dyeing of polyester with disperse dyes.     

Carrier‐free dyeing of radiation‐grafted polyester fabrics with disperse dyes

Carrier‐free dyeing of radiation‐grafted polyester fabrics with disperse red dye was studied in the temperature range 283–363 K. 1‐vinyl 2‐pyrrolidone (NVP), acrylic acid (AA) or their mixture was used to graft poly(ethylene terephthalate) (PET) fabric. The effects of pH of the dye solution, graft yield (GY), dyeing time (t), dye concentration (C), and dyeing temperature (T) on the colour difference (CD) of PET fabric were studied. The best dyeing condition was achieved at pH 5.5. CD increases linearly with the increase in GY, with slopes depending on the type of grafted copolymer. CD increased rapidly as the dyeing time increased; this was followed by a relatively slow dyeing rate within a few minutes. The initial dyeing rate (R) was found to increase with an increase in C and T. The dyeing rates for all grafted samples followed 0.35‐order kinetics and are temperature‐independent. Average activation energy 9.26 kJ mol^?1 is calculated for the dyeing process and is independent of the fabric treatment. Pre‐exponential rate constants 1976, 1839, and 1579 (CD/GY) s^?1 were calculated for dyeing PET samples grafted with AA/NVP mixture, NVP and AA, respectively, while 1074 CD s^?1 was evaluated for carrier dyeing of ungrafted fabric. Analysis of the kinetic parameters and the dyeing mechanism revealed that dyeing PET fabric was diffusion‐controlled. Grafting PET fabric improved significantly the dyeing affinity of the DR dye over ungrafted samples dyed in solutions containing a carrier. Copyright © 2005 Society of Chemical Industry     

One-bath dyeing of wool/polyester blends with acid and disperse dyes. Part 2 — disperse dye distribution on polyester and wool

Disperse dye distribution on polyester and wool during one-bath dyeing of wool/polyester blends is discussed. The addition of carriers increases the wool's intrinsic saturation value for disperse dye, thus raising the degree of staining on the wool component at the low dye uptakes. However, staining can be minimised if the dyeing is close to or attains equilibrium conditions. Sequestering agents can accelerate the disperse dye diffusion out of the wool fibre, further reducing staining on wool and transferring more disperse dyes from wool to polyester. Citric acid can be used as a sequestering agent as well as a pH adjusting agent.     

The dyeing of nylon with a microencapsulated disperse dye

Melamine resin microcapsules containing CI Disperse Blue 56 were prepared by in situ polymerisation. The microcapsules were characterised by their thermal properties and morphology, such as particle size and particle size distribution. The dyeing behaviour of the microcapsules on nylon 6.6 was evaluated. The microencapsulated dye exhibited good build-up, levelness and fastness properties. It has been demonstrated that microencapsulated disperse dye can be used to replace commercial disperse dyes in dyeing polyamide fabric without dyeing additives, and the resulting effluent can be easily recycled after filtration.     

Dispersant-free dyeing of polyester with temporarily solubilised disperse dyes

In an effort to overcome some of the environmental problems associated with the use of dispersing agents, four temporarily solubilised disperse dyes had previously been synthesised and characterised for use in dispersant-free polyester dyeing. In this paper the dyeing and fastness characteristics of these dyes on polyester fabrics have been examined. It was found that the optimum pH to guarantee a moderate rate of hydrolysis was 5, which allowed temporarily solubilised disperse dyes to be successfully applied to polyester without the use of dispersants. The dyebath remained stable during the dyeing procedure. The dyes exhibited good levelling and fastness properties on polyester.     

Afterclearing by ozonation: a novel approach for disperse dyeing of polyester

A set of trials has been conducted to examine the efficiency of ozonation afterclearing on poly(ethylene terephthalate) fibres dyed with disperse dyes. The afterclearing process was performed in neutral distilled water at room temperature with 12.8 ± 0.3 mg/min ozone at 400 ml/min ozone gas flow rate. The results indicate that 1 min ozonation time is adequate to achieve wash fastness results comparable with conventional reduction clearing without significant colour yield losses. Ozonation periods greater than 1 min not only caused significant colour yield losses, but also caused a severe decrease of the breaking load of the fabric. The advantages of ozonation afterclearing are: savings in energy and time, as it is performed at room temperature for only 1 min, and decrease of environmental load as it avoids the use of the harsh chemicals used in conventional reduction clearing.     

Modelling the properties of pigment‐dyed polyester/cotton sheeting fabrics by response surface methodology

The aim of this study was to model the effect of pigment, binder and fixer concentrations on the rubbing fastness, crease recovery, tear strength and stiffness of pigment‐dyed polyester/cotton sheeting fabrics. The design and analysis of experiments were carried out using Minitab^® statistical software according to the central composite design of response surface methodology. It was found that an increase in the binder concentration significantly improves the dry rubbing fastness, crease recovery and stiffness of the fabric, with a corresponding decrease in fabric tear strength, without significantly affecting the wet rubbing fastness. An increase in the fixer concentration significantly improves both the dry and wet rubbing fastness and crease recovery, with a decrease in fabric tear strength and stiffness. The effect of binder and fixer concentrations on crease recovery was not linear and there was significant negative interaction between these factors for dry rubbing fastness. The effect of pigment concentration was not found to be statistically significant for the types and range of concentrations of pigment, binder and fixer used in this study.     

Carrier dyeing of polyphenylene sulphide fabric with disperse dye

Polyphenylene sulphide is considered to be a high‐performance thermoplastic material and has been used in many areas over the past few decades. But the application of polyphenylene sulphide fabric used for protective clothing is limited because of difficulties in its dyeing and printing. In this work, carrier dyeing of polyphenylene sulphide fabric with disperse dye is discussed, and the effect of the structure of the carrier, dyeing temperature, dyeing time, usage of carrier and usage of dye on colour strength of the dyed sample and the percentage of dye exhaustion were investigated. In addition, the glass transition temperature, crystalline structure and orientation degree of treated polyphenylene sulphide fibre with benzyl benzoate were measured by differential scanning calorimetry, X‐ray diffraction analysis and velocity‐oriented tester, respectively. The results indicated that benzyl benzoate could increase the percentages of dye exhaustion and colour strength values, while at the same time reduce the glass transition temperature and orientation degree of the treated polyphenylene sulphide fibre. Thus, it would be beneficial to the diffusion of the dye molecules into the amorphous region of the fibre. Furthermore, the decrease of tensile strength and limiting oxygen index of the dyed polyphenylene sulphide sample was very little, and the colour fastness and levelness of the dyed polyphenylene sulphide samples were also satisfactory.     

One–bath dyeing of polyester/wool blend with disperse dyes

The present work aims to investigate and develop a one–bath dyeing process for most common blend fibres to replace the conventional two–step process usually applied to dye each fibre constituent separately. The main objectives of the proposed process is the conservation of energy, raw materials, dyes, auxiliaries and labour.     

Simultaneous afterclearing and decolorisation by ozonation after disperse dyeing of polyester

A set of trials have been conducted to examine the efficiency of ozonation on afterclearing of disperse dyed poly(ethylene terephthalate) fibres. Ozonation was performed in the cooled dyebath after the completion of the dyeing cycle. The ozone concentration used was 12.8 ± 0.3 mg/min at a gas flow rate of 400 ml/min. The results indicate that 3 min ozonation time is appropriate to achieve wash fastness results comparable to conventional reduction clearing. These results were obtained with simultaneous dyebath decolorisation ratios up to 67% and without significant colour yield ( K/S value) losses of the dyed fabric. Ozonation periods exceeding 3 min caused significant colour yield ( K/S value) losses, although dyebath decolorisation ratios increased up to 82% and wash fastness properties further improved. The chemical oxygen demand of the dyeing process decreased up to 62% by the ozonation afterclearing. The advantages of the ozonation afterclearing process are savings in terms of water, energy and time and reduction in environmental load.     

Improved mechanism of polyester dyeing with disperse dyes in finite dyebath

A new sorption mechanism of polyester dyeing with disperse dyes in water is proposed. It is considered dye aggregates could not be sorbed unless they turn into single molecules. However, this theory could not explain numerous sorption phenomena: sorption continues when equilibrium dye concentration exceeds its solubility; dyeing at long liquor ratio, using microencapsulated or crystal‐modified dyes do not change concentration of single dye molecules or dye solubility, but increase sorption rate and quantity in a fixed time. We demonstrate that both single and aggregated dye molecules could be sorbed using CI Disperse Blue 56. Because of the large size and low diffusion rate, dye aggregates could temporarily block sorption channel and prevent entry of other dyes. Therefore, only using extra more dyes could get a dark colour. Series of approaches could be proposed to reduce or eliminate the sorption problems caused by aggregates using the new sorption mechanism.     

Compatibility of a disperse dye mixture in supercritical carbon dioxide dyeing

The compatibility of three disperse dyes, CI Disperse Orange 30, CI Disperse Red 167 and CI Disperse Blue 79, which are commonly used as a trichromatic combination for conventional dyeing, was studied in supercritical carbon dioxide dyeing. Both the dyeing rate and the build‐up of the selected dyes were measured. Experimental results showed that they were quite compatible. The dyeings of a binary combination (CI Disperse Orange 30 and CI Disperse Blue 79, mass ratio 1:1) and a ternary combination (CI Disperse Orange 30, CI Disperse Red 167 and CI Disperse Blue 79, mass ratio 1:1:1) at different dye concentrations showed an on‐tone uptake and presented the same metric hue angles. This proved that the selected dyes could form a useful trichromatic combination in supercritical carbon dioxide dyeing. Furthermore, the uptake and exhaustion of the single dyes in supercritical carbon dioxide dyeing were similar to those in aqueous dyeing, implying that the dyeing media play only a minor role in the dyeing of polyester fibres with disperse dyes.     

Neutral dyeing of wool and wool/polyester blend fabrics using sulphatoethylsulphone reactive‐disperse dyes

Two models of temporarily anionic sulphatoethylsulphone reactive disperse dyes were applied to wool, polyester and wool/polyester blend fabrics at different dyeing pH. Maximum exhaustion values and colour yield were observed at pH 7. The results showed that reactive disperse dyes containing bis‐sulphatoethylsulphone reactive groups were more convenient for neutral dyeing of wool and wool/polyester blend fabrics if compared with a dye containing a mono‐sulphatoethylsulphone group. Excellent to very good wet fastness properties on all dyed fabrics were achieved.     

Effect of pH control on dyeing of polyester materials with disperse dyes

Dyeing of polyester materials with disperse dyes at a high temperature in the absence of carriers and at different ranges of dyebath pH was studied. It was found that the behaviour of the dye as well as the magnitude of dye uptake at different pH's are greatly affected by nature and position of the substituents of the dye. Substituents which from lyonium ions in acidic medium produce higher dye uptake in alkaline medium, and those which form lyate ions in alkaline medium bring about higher dye uptake in acidic medium. Substituents which are not able to form neither lyonium ions nor lyate ions yield practically the same dye uptake over a wide range of pH values.     

Effects of the phenol on the dyeing of polyester fibre with some disperse azo-dyes

The effects of the phenol, as carrier, on the dyeing rates, apparent diffusion coefficients, solubilities, thermodynamic affinities and T_D values of some disperse azo-dyes on polyester fibre are reported.The dyeing rates of less soluble dyes are higher than those of more soluble hydrophilic dyes, while the affinity and T_D values show a reversed behaviour.The carrier efficiency on the dyeing parameters studied appears to be correlated with the structure of dyes.     

The dyeing and colour characteristics of alkali–treated polyester fibres dyed with disperse dyes

Alkali–treated and untreated polyester fabrics were dyed for up to 6 h at 100°C with a series of six disperse dyes of different chemical structures. The alkali–treated polyester samples adsorbed more dye and were dyed to deeper depths of shade and slightly different shades than was the untreated polyester. The greatest differences were observed for the alkali–treated polyester with the most outer surface or skin removed. Dye structure and molecular size also affected the amount of dye adsorbed on the fibres, but did not delineate the nature of differences between skin and core morphology. This study shows that significant differences exist between the molecular structure of the skin and core of melt–spun polyester fibres.     

Modelling the properties of one‐step pigment‐dyed and finished polyester/cotton fabrics using response surface methodology

Dyeing of polyester/cotton blended fabrics with two different classes of dyes for polyester and cotton is a lengthy and expensive procedure owing to different fibre contents that need different auxiliaries, pH, and temperature conditions. The aim of this study was to investigate and model the properties of a combined pigment dyeing and hand‐building finishing system for polyester/cotton blended fabrics. The one‐step process was investigated using response surface methodology, taking concentrations of pigment, softener, and hand‐building finish as experimental variables. It was found that increase in hand‐building finish helps to improve colour fastness at higher pigment concentrations but results in deterioration in fabric tear strength. However, the decrease in tear strength can be minimised by increasing the softener concentration. For a 15 g l^?1 pigment concentration, optimum fabric tear strength, crease recovery angle, bending length, and dry and wet rubbing fastness properties were obtained using 60 g l^?1 of softener and 65 g l^?1 of hand‐building finish. The prediction equations developed in this study can be used to determine the required amounts of softener and hand‐building finish to achieve commercially acceptable results at different pigment concentrations.     

聚酯超细纤维用分散染料染色性能的研究

该文通过对现有的分散染料染色性能测试,如,聚酯超细纤维的移染性、皂洗牢度及高温分散稳定性等,并进行了碱性染色实验,为选择适用于聚酯超细纤维染色的染料提供一定的参考依据.     

Study of the removal of a disperse dye stain from a polyester/elastane blend

Polyethylene terephthalate and elastane fabrics were treated with azo disperse dyes in the same dyebath at 130 °C for 0, 30 and 60 min and then reduction cleared. The dyes adsorbed on each fabric were extracted using monochlorobenzene, in order to determine the amount of disperse dye in each of the polyethylene terephthalate and elastane fabrics, as the dyeing time was increased. It was observed that the amount of dye on the polyethylene terephthalate increased, while that on the elastane decreased, as the time at 130 °C increased from 0 to 60 min. After reduction clearing, the partition ratio of disperse dyes between the polyethylene terephthalate and the elastane increased. The dyed polyethylene terephthalate/elastane blend indicated that those dyes, which exhibited high partition ratios (polyethylene terephthalate:elastane), exhibited correspondingly higher wet fastness properties.     

Formulation and optimization of sucrose polyester physical properties by mixture response surface methodology

The physical properties of sucrose polyester (SPE), prepared from different composite blends of fatty acid methyl esters (FAME) of safflower oil, palm oil, and peanut oil, were evaluated by mixture response surface methodology. Optimum combinations of fatty, acids to achieve specific physical properties of SPE were determined. The SPE most similar in physical properties to peanut oil was obtained with a 55:45 molar ratio of mixed FAME from safflower oil and peanut oil. The physical properties of SPE were significantly affected by the degree of saturation and the average chainlength of their composite fatty acids.