• Textile Coloration and Finishing
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• v.32 no.2
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• pp.80-88
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• 2020

Supercritical fluid dyeing is a new alternative to the conventional aqueous process because of its environmental benefits. In this study, dyeing properties of Nylon 6 fabrics were investigated depending on dyeing temperature and pressure in supercritical CO₂ fluid dyeing system. In order to select the optimal condition for supercritical fluid dyeing of Nylon 6 fabrics, dyeing temperature and pressure were varied from 100, 110, 120℃, 200, 230, 260bar, respectively. The results of K/S values and levelling properties showed that the optimal dyeing condition for Nylon 6 fabrics was 110℃ and 230bar in the supercritical CO₂ fluid dyeing system. The washing fastness ratings of the dyed Nylon 6 fabrics under supercritical medium were good for both fading and staining except for staining on nylon.

• Textile Coloration and Finishing
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• v.15 no.2
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• pp.93-101
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• 2003

To acquire dyeing ability on aramid(Nomex) spun yarn in supercritical fluid dyeing, supercritical fluid dying(SFD) machine of 3L scale was designed. C. I. Disperse Red 60 and Red 360 were used in this work. It was possible to increase dyeing ability and to get level dyeing of fiber by attaching assistance devices(controlling device of supercritical fluid, nozzle, cover of carrier, etc.) to SFD machine. Physical properties(tensile strength, elongation, shrinkage) of Nomex spun yam treated by SFD were not changed. K/S values of dyed Nomex spun yam with Red 360 were higher than that with Red 60 and color fastness of dyed Nomex spun yam by SFD was similar to that by conventional dyeing method.

• Textile Coloration and Finishing
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• v.31 no.1
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• pp.25-32
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• 2019

The influence of the contact amount of carbon dioxide per unit mass of dyestuff(${\alpha}$) on dyeing uniformity in supercritical fluid dyeing is analyzed in this study. The experiments using a 5L class Pilot Scale dyeing machine is carried out for this study purpose. For a fixed temperature and pressure, the amount of sample and the dyeing leveling time were considered as process variables. The results show that the increase in the amount of the sample causes a higher color difference than the reference sample, and it also increases the amount of residual dye. On the other hand, the color difference tended to decrease with the increase in dyeing time. Based on these results, the correlation between ${\alpha}$ value and dyeing uniformity in supercritical fluid dyeing is obtained.

• Textile Coloration and Finishing
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• v.32 no.4
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• pp.208-216
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• 2020

In this study, C.I. Disperse Red 60 (DR60), C.I. Disperse Yellow 54 (DY54) dyes were used to investigate the washing fastness characteristics of PET fibers according to supercritical CO2 and aqueous dyeing process. The changes in K/S values and L⁎ values before and after washing of dyed PET fibers were observed according to the KS K ISO 105 washing fastness measurement method. In addition, it was confirmed by changing the ΔE⁎ and ΔL⁎ values of control PET fibers. Overall, it was confirmed that both the supercritical CO2 and aqueous dyeing process had excellent washing fastness ratings of 4-5 for DR60 and DY54 dyes. Comparatively, the K/S and L⁎ values for before and after washing of PET fibers with supercritical CO2 dyeing process was higher than that of the aqueous dyeing process and the ΔE⁎ and ΔL⁎ values of the control PET fibers were low. From the results, we observed that the supercritical CO2 dyeing process of PET fibers has better washing fastness characteristics than the aqueous dyeing process.

• Clean Technology
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• v.24 no.1
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• pp.1-8
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• 2018

As the social demands for environmental pollution increase and regulations on the dyeing process wastewater are strengthened, supercritical dyeing process has been attracting attention as an alternative technology to reduce wastewater and energy consumption. In the supercritical dyeing process where carbon dioxide is used as a solvent instead of water as a solvent, there is no wastewater generated. The unfixed dyes can be reused later which makes the process environment-friendly. Also, after dyeing process, dried textiles can be obtained without additional drying process, which makes the process energy efficient. In this article, we have summarized the development of the supercritical dyeing process along with the research in Korea today and compared the principle of supercritical dyeing process with conventional dyeing process. To further explain the principle, studies of the distribution factor and mass transfer of dyes in supercritical carbon dioxide and fibers, as well as solubility between supercritical $CO_2$ and dyes are discussed. The dynamic behavior of dyes in supercritical dyeing apparatus and summary of the supercritical dyeing facilities developed around the world are also discussed. Finally, we suggest the direction of research and development for optimization of supercritical dyeing process and application to synthetic fibers and natural fibers except for polyester.

• Textile Coloration and Finishing
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• v.31 no.1
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• pp.48-64
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• 2019

With evolution in the production environment of the textile industry, the need for non-water-based dyeing technologies and eco-friendly process facilities in the dyeing and processing stages has increased. In recent years, supercritical fluid dyes have been developed and commercialized in Europe, centering on this demand. However, so far, such dyes have been mainly applied in the processing of PET fibers. Basic research has mainly involved investigation of dyeing by supercritical carbon dioxide or solubility of such dyes, and more in-depth research should be continuously carried out. In this review, we describe the types and characteristics of supercritical fluids that exhibit specific properties at pressures and temperatures over the critical point. In addition, the state of the art in the dyeing and processing technology using supercritical fluids and associated, processing problems, environmental regulation, and wastewater treatment issues are described in detail. We hope this review can contribute to the supercritical fluid technology being further developed as an environment friendly dyeing processing method. Furthermore, we expect that the technique can be used as a means of ensuring different, high-quality dyed products.

• Textile Coloration and Finishing
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• v.31 no.1
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• pp.14-24
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• 2019

In this study, dyeability of PET fabric was investigated depending on dyeing temperature, pressure, and leveling time using laboratory scale supercritical $CO_2(scCO_2)$ dyeing machine. Dyeing temperature, pressure, leveling time were varied from 100, 120, $130^{\circ}C$, 150, 200, 250bar, 40, 60, 80, 100min, respectively. It is proved that the higher temperature of $scCO_2$ dyeing process, the higher K/S value and the lower $L^*$ value, which in turn means the lower amount of dyeing molecules remained after process done. Compared 200bar with 250bar of dyeing pressure, $scCO_2$ dyeing fabrics under 250bar appeared to have a lower $L^*$ value, a higher K/S value than those from 200bar, meaning that dyeing color turns to darker with higher dyeing pressure. The experiments showed that the most ideal condition for $scCO_2$ dyeing process is $120^{\circ}C$, 250bar for 60 - 100min of leveling time.

• Textile Coloration and Finishing
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• v.31 no.3
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• pp.147-154
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• 2019

In this study, poly(ethylene terephthalate)(PET) fibres dyed with Disperse Red 167 using supercritical $CO_2$ technology. The purpose of this study was to investigate relationship between PET fibers and supercritical $CO_2$ during dyeing. The effects of temperature, pressure, dyeing time and mass ratio between the dye and PET in the dyeing chamber were considered. Thermal and mechanical properties of the fibers were investigated. Tensile strength of dyed PET fibers decreased at higher temperature and pressure conditions. DSC and DMA results indicated that the Tg and Tm values decreased significantly when compared to the pure PET fibers. However, uniformly dyed PET fibers were typically observed.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.715-718
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• 2002

The supercritical dyeing process has been gaining the increasing importance because of environment reason. For further development of this process, it is needed to measure the solubility in supercritical fluids in the extensive ranges of temperature and pressure. In this study, using the semi-flow type apparatus consisted of supercritical fluid equilibrium cell, the solubility of disperse dye(C.I. disperse red 60) in supercritical HFC-134a has been measured at the temperatures of 383.2 K and 413.2 K, and in the pressure range of 50 bar to 160 bar. The solubility data are, with good agreement, correlated by an expanded liquid model which considers the supercritical fluid as compressed liquid.

• Textile Coloration and Finishing
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• v.33 no.1
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• pp.31-39
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• 2021

In this study, the dyeing properties of supercritical fluid dyed nylon fabrics were investigated which use two types of dyes for dyeing nylon. For other dyeing conditions were referred to related literature, and dyeing was performed with different dyeing concentrations. Dyeability was confirmed through measurement of washing fastness and color coordinate, and a calibration curve of each dye was drawn up and the absorbance of the residual dye was measured to confirm the amount of residual dye and the dye exhaustion rate at the corresponding concentration. As a result of color difference measurement, the color intensity increased as the concentration increased, but the increase was insignificant at high concentration. This tendency was more obvious in C.I. Disperse Orange 155 than in C.I. Disperse Yellow 42. The dye absorption rate also decreases as the concentration increases, but at 0.85% o.w.f concentration, C.I. Disperse Yellow 42 was 97.29% and C.I. Disperse Orange 155 was 93.77%. For both dyes, the wash fastness dropped by 0.5 to 1 class from the sample that was dyed at a concentration of 0.5% o.w.f in the wash fastness test.