Topping of naturally dyed wool fabrics with different natural dye sources

Wool fabrics can be dyed with synthetic dyes and even with natural dyes. To present a different aspect to the coloration of wool, the current study was focused on a topping process (ie, the dyeing of wool that was already dyed) with different natural dye sources. For this purpose, the fabrics that were already dyed with a natural dye source were once again dyed with two different natural dyes. In bottom dyeing (bottoming), fabrics were dyed with hops (Humulus lupulus L.) in the presence of different mordanting agents. Then the dyed, washed and dried samples were once again dyed (topping) with two different natural dye sources. For topping, powdered madder and acorn were tested in direct dyeing of wool samples. Finally, the colour changes were analysed with the use of a spectrophotometer. The study demonstrates that such a process (ie, bottoming with hops in the presence of different mordanting agents and then topping with madder or acorn) can be a way of obtaining different shades and colours with sufficient/good fastness values by natural dyeing.     

Dyeing natural fibres in supercritical carbon dioxide using a nonionic surfactant reverse micellar system

A reverse micellar system in supercritical carbon dioxide has been developed as a dyeing medium. Water-soluble dyes such as reactive dyes and acid dyes could be sufficiently solubilised in the interior of a specially constituted reverse micelle. Protein fabrics, silk and wool, were satisfactorily dyed even in deep shades with conventional acid dyes without any special pretreatment. Cotton cellulose fabric was also dyed with conventional reactive dyes when the electrostatic force of repulsion between dye and cotton was eliminated. Compared to previously proposed supercritical dyeing methods, dyeing of fabrics with this system could be performed at low temperatures and pressures in a short time.     

Dyeing behaviour of lyocell fabric: effect of fibrillation

To understand the effect of fibrillation in dyeing, non-fibrillated lyocell fabrics and fibrillated lyocell fabrics were dyed with different types of reactive dyes. Their exhaustion, fixation and K/S values were measured and compared. It was observed that fibrillated lyocell shows lower visual colour yield than non-fibrillated lyocell, independent of the exhaustion and fixation. It was also observed that some bifunctional reactive dyes, because of the location of reactive groups and flexibility of their structure, reduced fibrillation of lyocell through crosslinking. It was shown that defibrillating fibrillated lyocell with a cellulase enzyme increased the visual colour yield. Non-fibrillated lyocell fabrics after dyeing were subjected to a hydroentanglement treatment to create a fibrillation effect. These properties suggest that the lower visual colour yield of fibrillated lyocell is not mainly attributed to any change in fibre properties of the fibrils, but as a result of the light scattering from the fibrillated fabric surface.     

Mechanical Properties and Stability to Light Exposure for Dyed Egyptian Cotton Fabrics with Natural and Synthetic Dyes

Synthetic dyes are more available than natural dyes were in the past, because of lower prices and wider ranges of bright shades with considerably improved color fastness properties. In current years, concern for the environment has created an increasing demand for natural dyes, which are friendlier to the environment than are synthetic dyes. The aim of this work is to study the effect of dyeing cotton fabrics with both a natural dye (henna) and a synthetic dye (Remazol blue) on some mechanical properties and those of stability to light exposure. The undyed and dyed cotton fabrics were tested for their mechanical behaviors expressed as tenacity (N), elongation %, and work-breaking (N · m). They were also tested for shrinkage and crease recovery angle. The stability to light before and after 100 h exposure was examined by investigating the microstructure [using x-ray diffraction (XRD)] and macrostructure [using a scanning electron microscope (SEM)] and the reflection spectra. The results proved that the cotton samples dyed with Henna dye have higher mechanical properties than those dyed with “Remazol” reactive dye. Moreover, the light fading behaviors of both synthetic and natural dyes were studied in terms of the reflection spectra (400–800 nm), microstructure, and macrostructure of the sample's fibers.     

Camouflage of cotton fabrics in visible and NIR region using three selected vat dyes

To provide camouflage in near infrared (NIR) region and imitate reflectance profile of greenish leaves, cotton fabrics were dyed with three selected vat dyes, namely C.I. Vat Blue 6, C.I. Vat Yellow 2, and C.I. Vat Red 13. Reflectance curves of two types of fresh greenish leaves were measured as standard reference. Transmittance curve of vat dyes in acetone solution indicated that selected vat dyes have suitable structure to provide camouflage in NIR region. According to reflectance profiles, reflectance curve of Vat Blue 6 has more similarity with that of green leaf at the concentration of 0.85% owf (on weight of fiber) and 1.2% owf in comparison with those of C.I. Vat Yellow 2 and C.I. Vat Red 13. Cotton fabrics were dyed with different mixtures of the dyes to obtain a standard shade to reach camouflage in visible range. Chromatic values of dyed fabrics were measured (CIE1976 L*, a*, and b*) and two standard shades of the 1948 US army pattern, NATO and forest green, were obtained on cotton fabrics with ΔE_CMC < 2. Reflectance profiles of these two shades were located between the reflectance of green leaves. So, two vat dyes were introduced to camouflage dyes group, C.I. Vat Blue 6 and C.I. Vat Red 13, and used to achieve NATO green and forest green shades for first time. All dyed samples showed good fastness properties. The effect of washing and light exposure on camouflage properties of fabrics in visible and NIR region was inconsiderable. © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 200–207, 2014     

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.     

A hemicyanine fluorescent reactive cationic dye: synthesis and applications on wool fabrics

A novel hemicyanine fluorescent reactive cationic dye was synthesised by the reaction between the free amino group of a hemicyanine fluorescent dye and 2,3‐dibromopropionyl chloride. The dye was characterised by proton nuclear magnetic resonance spectroscopy, high‐resolution mass spectrometry, ultraviolet‐visible absorption spectrometry, and single‐photon fluorescence spectrometry. The prepared dye was applied to wool fabrics to give fluorescent orange shades. The colour fastness of the dyed wool fabrics was tested. Results show that dyed fabrics using the novel hemicyanine fluorescent reactive cationic dye could be used as fluorescent clothing.     

关于活性染料及分散染料色牢度几个热点问题的探讨

由于纺织品服装的染色牢度要求越来越高，特别是活性染料浅色染色物的耐晒牢度和深浓色织物的水洗牢度和湿摩擦牢度；分散染料染色物热迁移牢度等，成为提高纺织品服装质量的瓶颈，引起广泛关注的热点问题。本文就染料选用、助剂开发及染料加工工艺合理化进行详细探讨，给出解决办法。有15篇参考文献。     

A method for dyeing cotton fabric with anthocyanin dyes extracted from mulberry (Morus rubra) fruits

For the first time, the natural anthocyanin dyes (mainly consisting of cyanidine 3‐glycoside) extracted from mulberry (Morus rubra) fruits has been successfully used to dye cotton fabric, with a dyeing property performance good enough for potential commercial applications. In this study, succinic acid was firstly incorporated into cotton fabrics by esterification to the hydroxyl groups of cellulose, forming an anionic site for the dyes. The performance of the modified material was characterised by Fourier transform infrared spectroscopy and tensile strength. Results showed that the tensile strength of cotton fabrics was mostly retained after modification. The anthocyanin extracts from mulberry fruits were used to study the dyeability of the control and modified cotton fabrics. Red and deep purple (aubergine) are two main shades of cotton fabrics dyed with mulberry fruit extracts. Most importantly, aubergine shade is rare in cotton fabrics dyed with natural dyes. Modification with succinic acid clearly increased the colour strength of the dyed cotton fabric. The colour strength of dyed cotton fabric was improved from 2.7 to 5.3 in the case of dyeing without mordants, and from 3.2 to 6.9 in the case of dyeing with tin mordanting. Meanwhile, the colour fastness was improved by 0.5–2 grades with increasing succinic acid concentration in the finish solution. The colour fastness to perspiration, crocking, light, and washing of fabric dyed with simultaneous tin mordanting and modified with 30 g l^?1 of succinic acid was found to be acceptable, with a grey scale grade of at least 3. As for home laundering, neutral soapy solution was more acceptable than alkaline soapy solution.     

Electrostatic self‐assembly dyeing of cotton fabrics

A new approach to the dyeing of cotton fabrics using an electrostatic self‐assembly method was evaluated. Cotton fabrics were pretreated with 2,3‐epoxypropyltrimethylammonuium chloride and cationic charges were produced on the fabric surfaces. For the dyeing of cotton fabric, reactive and acid dyes were used. Oppositely charged anionic reactive/acid dyes and cationic poly(diallyldimethylammonium chloride) were alternately deposited on the surface of cationised cotton fabrics. Ten multilayer films of dye/poly(diallyldimethylammonium chloride) were deposited on the cotton fabric surfaces using a padder. The build‐up of the multilayer films and the level of colour strength (K/S) achieved are discussed. Samples of cotton fabrics were also dyed with the same dyes, but using the exhaust method, and both types of dyed samples were compared. The washing, rubbing and light fastness properties were evaluated for the dyed fabrics.     

Reactive dyeing of cellulosic fibers: Use of cationic surfactants and their interaction with reactive dyes

Cotton fabrics were dyed with three reactive dyes, C.I Reactive Blue 263, C.I Reactive Red 269, and C.I Reactive Yellow 208, after pretreatment of the fabrics with three alkyl trimethyl‐ammonium bromides (tmabs) having 12, 14, and 16 carbon atoms in the alkyl chain. The pretreated samples were dyed with standard dyeing methods using conventional, reduced amounts of electrolyte, and no electrolyte. Pretreatment with the three cationics (tmabs) resulted in an increase in dye exhaustion with all dyes used, whereas total dye fixation was lower for both red and blue dye and equal for the yellow, when compared to the reference untreated samples dyed according to the same standard dyeing method. The interaction between dodecyl trimethyl‐ammonium bromide and the three dyes was studied and the stoichiometry of the various dye/dodecyl trimethyl‐ammonium bromide (12‐tmab) complexes formed has been deduced. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Reactive dyeing of silk using commercial acid dyes based on a three‐component Mannich‐type reaction

Acid dyes are employed for commercially dyeing silk, which results in ionic bonds between the silk fibroin and the dye. This generally leads to low wet fastness properties for dyed silk fabrics. In this work, three commercial acid dyes with aromatic primary amine structures were selected to dye silk using a Mannich‐type reaction, resulting in improved wet fastness of dyed silk by forming covalent bonds between silk fibroin and dye. The Mannich‐type reactive dyeing was applied to silk fabrics at both 30 and 90°C in trials. Dyeing at 90°C can shorten the dyeing time compared with dyeing at 30°C, even although dye exhaustion and relative fixation at 90°C were a little lower. The dyeing process was optimised when the dyeing temperature was 90°C, dyebath pH 4, dye‐to‐formaldehyde ratio 1:30 and holding dyeing time 60 minutes. The results showed that the dye exhaustion on silk fabrics for the three aromatic primary amine‐containing acid dyes exceeded 94% and their relative fixation was over 80%. Their washing and rubbing fastness reached grade 4 or higher. Hence, the colour fastness properties of dyed silk fabrics using the Mannich‐type reactive dyeing method is superior to the conventional acid dyeing method using the same aromatic primary amine‐containing acid dyes. The Mannich‐type reactive dyeing for silk fabrics at 90°C can be developed into a novel and rapid reactive dyeing method, promising an effective dyeing process with excellent colour fastness.     

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.     

Prediction of depth of shade of a dyed polyester fabric based on fibre fineness and fabric structure

A colour prediction model containing four parameters of dye concentration, fibre fineness, fabric roughness and dye parameter is developed. The model can predict the shade depth of a dyed polyester fabric. The relationship among these factors and shade depths of dyed polyester fabrics was investigated to elucidate the role of fibre fineness and fabric structure on surface reflectance and colour efficiency. The shades of several additional dyed samples were measured and compared against the predicated values to validate the accuracy and performance of the model. The results showed that the predicated depths of shade matched the experimental data to a good extent.     

Dye binary mixture formulation by means of derivative ratio spectra of the Kubelka–Munk function

In this study, a new method is introduced for the determination of dye concentration in fabrics dyed with bicomponent dye mixtures. The reflectance spectra of the samples dyed with different binary mixtures of dyes were recorded between 400 and 700 nm. The obtained spectra were divided by a standard spectrum of each of the components in the mixtures and the derivative spectra were calculated. The amounts of dyes were determined by measurements in suitably selected wavelengths in the acquired derivative ratio spectra. The obtained results indicate that the developed derivative ratio spectra method is more accurate than the normal Kubelka–Munk method. The proposed derivative method is simple, accurate, and suitable for quantitative analysis of samples dyed with binary mixed shades. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2010     

Investigation of the clean patterning possibilities on cotton socks through laser technology

The aim of this research is to reveal the effect of laser treatment at different resolutions (10, 20 and 30 dpi) and pixel times (80, 100 and 120 μs) on reactive dye uptake of cotton fabrics and the fastness values obtained. Yellowness index, Fourier Transform–infrared analysis, scanning electron microscopy analysis and bursting strength tests were applied to samples. The samples treated with laser were dyed in lighter shades than the untreated ones, with all three of the reactive dyes used in the experiments. In general, colour yield values decreased when the resolution and pixel time increased. However, no significant change was observed in washing, rubbing, light and perspiration fastness values. The possibilities of obtaining various patterns on cotton socks dyed with reactive dyes by laser treatment at different resolutions and pixel times were also investigated. According to the results, it was determined that if laser treatment was not applied to some parts of reactive dyed cotton socks, and 10 dpi 100 μs and 20 dpi 100 μs laser was applied to other parts of those socks, then it was possible to obtain patterns with different shades of the same colour on the socks. On the other hand, laser application after dyeing does not have a negative effect on fastness values. After determining the optimum conditions for the laser process, non-see-through tights were produced with cotton yarn on the front and polyester/elastane yarn on the back, and patterns were obtained by applying laser treatment before or after dyeing via sample scale industrial production.     

Synthesis and application of a hetero-bifunctional disulphidebis(ethylsulphone/monochlorotriazine) reactive dye

The behaviour of a heterobifunctional reactive dye based on a disulphidebis(ethylsulphone/monochlorotriazine) reactive system has been investigated. Relatively high degrees of exhaustion and fixation were achieved for cotton fabrics dyed with the disulphidebis(ethylsulphone/monochlorotriazine) reactive dye compared to bifunctional sulphatoethylsulphone/monochlorotriazine and/or conventional monofunctional monochlorotriazine reactive dyes. The results also indicate that the fastness properties are approximately the same for all the dyes studied in this investigation.     

Kinetics of thermo-fixation of solvent dyes and pigments in polyester fibres

The diffusion coefficient of a dye in fibres is critical to understanding the dyeing process and coloration quality of products. In this paper, the diffusion kinetics of solvent dyes in the thermosol dyeing of polyester fibres was studied by measuring K / S of the dyed polyester fabrics based on the Kubelka–Munk equation. The diffusion coefficients of two model solvent dyes were estimated with Hill's equation using the experimentally measured K / S values and were found to be in good agreement with those calculated from the traditional extraction method. Such a measurement method was applied to several other solvent dyes and pigments that have different molecular sizes and a good correlation between the measured diffusion coefficients and sizes of these dyes and pigments was found. The results indicate that it is feasible to use K / S measurement of dyed fabrics and Hill's equation to evaluate the kinetics of the thermosol dyeing process under certain conditions.     

涤纶常压染色促染剂的制备及应用

以有机碱三乙醇胺为催化剂,邻苯二甲酸酐(简称苯酐)与自制阳离子改性剂WLS反应,制备苯酯助剂,并将其作为涤纶分散黑ECT染料常压染色的促染剂。通过系统研究,优化出苯酯合成工艺,并探讨苯酯助剂与N-正丁基邻苯二甲酰亚胺(简称亚胺)复配对分散黑ECT常压染色性能的影响。结果表明:苯酯与亚胺有很好的协同效应,二者质量比按2∶1复配时,可获得最佳染色效果。该复配促染剂应用于涤纶常压染色中,染色后织物先进行195℃焙烘2.5 min,再还原清洗,织物的染色深度K/S值和上染百分率较常压无助剂、同条件染色工艺显著提高,而且基本达到传统高温高压的染色效果。     

Evaluation of colour fastness and thermal migration in softened polylactic acid fabrics dyed with disperse dyes of differing hydrophobicity

This paper addresses the relative effects of softeners having different properties and their method of application (exhaust vs pad) on the colour fastness of poly(lactic acid) fabrics dyed with a range of disperse dyes with different levels of hydrophobicity. A comparison was made with a correspondingly finished polyethylene terephthalate fabric. Possible relationships between the levels of hydrophilicity/hydrophobicity of the dye, and softener, and the colour fastness were explored. Finally, the amount of dye thermally migrated into the finish on the softened poly(lactic acid) and polyethylene terephthalate fabrics was examined in comparison with their colour fastness. Softened poly(lactic acid) fabrics dyed with CI Disperse Red 167.1 exhibited more thermal migration, and hence lower colour fastness, than the corresponding polyethylene terephthalate fabrics. Conversely, softened poly(lactic acid) fabrics dyed with Dianix Deep Red SF exhibited less thermal migration, and hence better colour fastness, than the corresponding polyethylene terephthalate fabrics. Overall, no clear relationship was found between the hydrophobic nature of the disperse dye and the hydrophobic character of the softener on the colour fastness.