Dyebath pH Research Articles

Natural Bio-Source Materials for Green Dyeing of Cellulosic Yarns

ABSTRACT There is a growing literature investigating to use natural materials for dyeing textiles on account of their low toxicity, eco-friendliness, sustainability, and better biodegradability. In this way, this article presents the results of a study into the applications of tamarind hull and marzangoosh in a fully eco-friendly manner to dye cotton yarns. The effect of the main dyeing conditions (dye concentration, bath pH, time, and temperature) on the color efficiency (K/S) was investigated with a reflectance spectrophotometer. Results indicate that at optimized conditions, pre-mordanting yarns with tamarind hull as an eco-friendly mordant lead to the formation of an insoluble complex on cotton yarns followed by increased dye adsorption, which enhances the light and wash fastness properties. The SEM photographs showed that pre-mordanting cotton yarns with tamarind hull increase the surface porosity. Finally, based on our observations, it may be claimed that cotton yarns subjected to both pre-mordanting and dyeing exhibited a good antibacterial activity and the procedure proposed in this study seems to be of potential use for the production of medical textiles without adverse environmental impacts.

RSM Optimization of Wool Dyeing with Berberis Thunbergii DC Leaves as a New Source of Natural Dye

ABSTRACT With the aim of introducing a new source of natural dye and developing a sustainable coloration process, the dyeing of wool with the leaves of Berberis thunbergii DC was optimized using response surface methodology. The results showed that increasing the dye concentration and dyebath temperature increased the color strength (K/S) and increasing the dyebath pH and mordant concentration decreased the K/S. The optimum pH, dye concentration, dyeing temperature, and mordant concentration for obtaining the highest K/S were 5, 146%owf, 76°C, and 3.8%owf, respectively. The sample dyed under the optimal conditions showed good color fastness properties.

UV Protection and Dyeing Properties of Wool Fabrics Dyed with Aqueous Extracts of Madder Roots, Chamomiles, Pomegranate Peels, and Apple Tree Branches Barks

ABSTRACT This paper studies the dyeing properties of wool fabrics dyed with aqueous extracts of madder roots, chamomiles, pomegranate peels, and apple tree branches (obtained after pruning) barks. We have thoroughly investigated the effects of dye bath pH and mordants on the color properties of the aforementioned fabrics. Even without mordanting, the wool fabrics dyed with the pomegranate peel have the highest value of color strength (K/S = 14). Mordanting permits to produce different colors and improve the fastness of a dye, especially for madder roots, chamomile, and apple tree branches bark. UV protection of wool fabrics increased after natural dyeing, and it was more improved after mordanting especially with ferrous sulfate. Experimental results show that the fastness properties of dyed wool fabrics range from average to excellent even without mordanting.

Dyeing of Innovative Bicomponent Filament Fabrics (PET/PTT) by Disperse Dyestuffs: Characterization and Optimization Process

PET/PTT bicomponent filaments yarn is produced by two polymers: the polyethylene terephthalate (PET) and the polytrimethylene terephtalate (PTT) extruded side by side. This yarn is known for its high mechanical properties in particular elasticity and elastic recovery. However, differences between physical and chemical properties of the two components make the dyeing step of this yarn complicated. The aim of this work is the development of a dyeing process for bicomponent filaments without altering their physical and chemical properties. Different techniques such as SEM, FTIR, and differential scanning calorimetry (DSC) were used to characterize the studied yarn. For dyeing, three different disperse dyes CI Disperse Red 167.1, CI Disperse Yellow 211, and CI Disperse Red 60 with different energy classes were studied. The influence of dyeing conditions in particular dyeing temperature, pH of dye bath, dyeing time, and carrier concentration in the dye bath was evaluated. Responses analyzed are color strength (K/S), colorimetric coordinates and color fastness of samples dyed with studied dyes. In addition, the stability of elasticity and elastic recovery of bicomponent filament fabrics after the dyeing process has been also verified and proved.

Environmentally Friendly Surface Treatment of Wool Fiber with Plasma and Chitosan for Improved Coloration with Cochineal and Safflower Natural Dyes

In this study, the effect of surface modification of wool fiber with oxygen plasma and chitosan (PC) on the color strength of the samples dyed with cochineal and safflower natural dyes has been studied. According to colorimetric measurements, plasma and chitosan treatments resulted in notable improvements in dyeability of wool fibers. The plasma and chitosan-treated wool sample could be dyed in less time and at lower temperature compared with untreated one. The dyebath pH had a prominent effect on color strength, which showed that the electrostatic force has an important role in dye adsorption. The optimum pH for maximum dye absorption was 3.6. The fastness properties, tensile strength, and elongation at break of dyed wool were improved after PC treatment. Scanning electron microscopy (SEM) images and ATR-FTIR analysis proved the coating of wool scales with a uniform thin layer of chitosan, which caused the improved dyeability of wool fibers with safflower and cochineal.

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

AbstractAcid 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.

Optimization of Dyeing Process of Cotton Fabric with Cochineal Dye

The objective of this research is to optimize the dyeing parameters for cotton fabric with natural dyestuff extracted from Dactylopius coccus. In order to obtain purple hue, the influence of dyeing process conditions i.e. dye bath pH, concentration of dyestuff, and the addition of electrolyte has been studied. Additionally, potassium aluminium sulfate dodecahydrate and iron (II) sulfate heptahydrate were used as mordants on cotton fabrics in order to obtain coloration of specific purple hue. Colorimetric data and fastness properties of the dyed samples have been analyzed. Results indicate that the dyeing parameters as well as pre-treatment has a significant influence on the obtained purple shades and fastness properties.

Application of D‐optimal design in the analysis and modelling of dyeing of plasma‐treated wool with three natural dyes

AbstractBoth the dyeing and finishing of textiles with natural compounds are gaining increasing attention because of various environmental and health problems associated with the use of synthetic reagents. In this study, wool fibres were dyed with three natural dyes, namely, Arnebia euchroma, cotton pods and harmal seeds. Alum was used as the mordant, and samples were mordanted by the premordanting method. Oxygen plasma was employed for the surface modification of wool. Plasma treatment time, alum concentration, dyebath temperature and pH were selected as the process variables, and their effects on the K/S of the dyed samples were analysed using D‐optimal design. The surface topography, morphology and chemistry of the wool fibres after plasma treatment were studied by atomic force microscopy (AFM), scanning electron microscopy (SEM) and Fourier Transform–infrared spectroscopy (FTIR), respectively. FTIR confirmed the creation of new oxygen‐containing groups on the surface of wool fibres after plasma treatment. SEM and AFM images confirmed the surface etching and increase in the roughness of plasma‐treated fibres. Increasing the dyebath pH and temperature increased the K/S of the dyed samples. Increasing the amount of alum mordant increased the K/S of samples dyed with cotton pods but decreased the K/S of samples dyed with A. euchroma and harmal seeds. Increasing the plasma treatment time improved the K/S of samples dyed with A. euchroma and cotton pods but had no significant effect on the K/S of samples dyed with harmal seeds.

Banana peel in dyeing of polyamide/elastane blend fabric

PurposeThe purpose of this paper is to show the dyeing effect of banana peel on polyamide fabric by using various mordants and to reveal alternatives to metallic mordants.Design/methodology/approachThe simultaneous mordanting method was used in the dyeing process.FindingsFrom environmental and economical points of view, this paper studies the use of a natural waste product in textile dyeing. Assessment of domestic organic wastes will provide new possibilities for valorization of biomaterials. It is concluded that colorimetric data are affected by the amount of plant used in extraction, amount and type of mordant and pH of dye bath. Tin II chloride ensured the lightest color shades. No alternative mordants could be presented to iron II sulfate and tin II chloride, as they generated completely different color shades. Acids can be an alternative to 0.8 g/L alum mordant. Ammonium sulfate and sodium acetate also generated similar colors to alum. Ammonium sulfate can be substituted for citric acid and alum. Banana peel can be considered as a natural dye source for polyamide elastane blend fabric.Originality/valueBanana peel can be suggested as a natural colorant with good wash fastness for dyeing of polyamide elastane blend fabric.

Effective Dyeing of Cotton Fibers Using Cynomorium Coccineum L. Peel Extracts: Study of the Influential Factors Using Surface Response Methodology

ABSTRACT The current paper focuses on the use of Cynomorium Coccineum peels extract for cotton fibers dyeing in an easy and effective way without the use of mordants. Prepared extracts were analyzed using UV-visible, FT-IR spectroscopy, Total Contents both Phenolic (TPC) and Flavanoid (TFC) and their ability to reduce reactive species by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging motion experiments. The effect of the most important dyeing conditions, including dyebath pH, temperature, extract concentration, and time contact on the performance of cotton fibers dyeing was discussed. Data were assessed by the measurement of the color strength (K/S). A surface design was adopted to assess the influential factors and the interaction effects of the studied parameters. The optimal conditions for dyeing were to be: pH = 5.5, T = 72.5°C, extract concentration = 0.275% and dyeing duration = 25 min. As also observed, changing the concentration of the electrolyte NaCl, the color strength can be improved. Overall, the friendly extracted dye exhibited excellent textile dyeing characteristics with uniform morphology as proved by SEM analysis and good fastness to washing, perspiration, and rubbing.

Application of natural dye on polytrimethylene terephthalate fiber

PurposeThis paper aims to investigate the feasibility of developing an eco-friendly dyeing process for a regenerated polyester fiber (polytrimethylene terephthalate) using a natural dye (Lac) and bio-mordant.Design/methodology/approachThe effects of temperature, time, initial pH of dye bath, material to liquor ratio and mordant concentration on color strength of polytrimethylene terephthalate fiber dyed with Lac were examined. The results were compared using three bio-mordant (catechu, myrobalan and pomegranate) and three inorganic mordant (alum, ferrous sulfate and stannous chloride). Single replicate of 25-design methodology was used to identify three significant factors affecting color strength, and optimization was done using response surface methodology based on 23-central composite rotatable design.FindingsColor strength achieved using catechu as a bio-mordant was close to that with ferrous sulfate and higher than with stannous chloride. Temperature, initial pH and mordant concentration were identified as significant factors affecting color strength of dyed fiber with catechu. Optimization revealed temperature of 133OC, initial pH of 6 and bio-mordant (Catechu) concentration of 10 per cent to be the optimal conditions for dyeing, with K/S value of 4.55.Originality/valueThe study revealed the possibility of satisfactory dyeing of regenerated polyester fibers with natural dyes, replacing disperse dyes. The comparison of color strength achieved indicated the possibility of replacing inorganic mordant with bio-mordant in such dyeing process. The dyeing process could thus be made more eco-friendly by removal of toxic chemicals from effluents.

Effect of Acid Donors on the Dyeing of Nylon Fiber with Acid Milling Dyes

The effective control of pH in the dyeing of nylon fibers with acid milling dyes for high exhaustion and levelness can be accomplished by the gradual pH shift toward acidic region as dyeing proceeds. 1,3-Dichloropropan-2-ol and ethylene glycol diformate were chosen as new pH sliding agents in this study. Their dyeing properties and ability to control the dye bath pH were measured and compared with those of the conventional acid donors such as ammonium sulfate and sodium acetate-acetic acid buffer solution. The small amount of new pH sliding agents lowered the dye bath pH to 4, achieved the percentage exhaustion of more than 95 %, and showed an excellent build-up property. The gradual decrease in the pH of the dye bath containing new pH sliding agents from the start of the dyeing process to the final stage was confirmed. Difference in the levelness of the dyed samples was not observed among the four acid donors and grades of color fastness of the nylon fabrics dyed with various pH control system were found in the similar level.

Standardization of Dyeing Process Variables for Dyeing of Cotton Khadi Fabric with Aqueous Extract of Babul Bark (Acacia Nilotica L.)

Study of dyeing process variables and its standardization is essential for establishing scientifically reproducible standard method of dyeing cotton fabric with specific natural dye like babul bark containing vegetable gallic/tannic acid residue besides natural color component. Effects of different single and combined double mordanting and dyeing process variables on surface color strength and color fastness properties after dyeing cotton khadi fabric with aqueous extract of Babul Bark (Acacia Nilotia L.) as natural dye were studied in the present work. Potash alum, aluminium sulphate and stannous chloride were used as metallic salt mordant and Harda (Myrobolan) was used as natural mordant assisting agent. Relevant results indicate that application of overall 15% dosages of Harda and aluminium sulphate in 75:25 ratio offers maximum K/S value (5.44) and overall good color fastness (3–4 or higher) than other combination studied. After finalizing the mordants, dyeing process variables were studied for standardization of the dyeing process using babul bark extract. Relevant results indicate that this particular natural dye (babul bark) renders better color strength for optimized conditions of dyeing with dyeing time: 60 min, dyeing temperature: 65 °C, at MLR: 1:30, dye bath pH: 5.0, optimum dye conc.: 30% (based on dry weight of source materials) and common salt—5%. Study of FTIR and Atomic absorption spectrophotometry (AAS) for the said natural dyed cotton khadi fabric with babul bark indicate presence of metallic mordant and tannin content for explaining the observed results showing dye-fibre-mordant complex formation besides hydrogen bonding as well.

Development and optimization of a non-traditional extraction process of yellow colorant from safflower petals as a natural colorant

Yellow colorant was extracted from safflower petals through grinding, sifting, washing, filtering and drying. The Safflower petals were submitted to innovative extraction using microwave irradiation and under a variety of conditions. Variables studies including safflower concentration, duration of extraction, extracted dye bath pH and temperature to optimize the extraction condition. The effects of dye concentration, dye path pH, colorant temperature, colorant time and liquor ratio, were studied in terms of dye uptake and shade. Conditional changes in the innovatively extracted colorant and dyeing process vis-a-vis those of non-traditional extraction and dyeing were presented. The obtained results showed that the innovative extraction as well as dyeing process using the microwave irradiation consumes less time and energy when compared with the non-traditional technique. The results indicate further that current extraction colorant using the microwave or non-traditional heating brings into focus yellow colorant, which induces excellent overall color fastness when applied as a colorant in the dyeing of different fabrics. The analysis of absorption mechanism suggested that the hydrogen bonding and electrostatic interactions operating between Safflower yellow colorant and different fabrics lead to Freundlich absorption, though other interactions such as hydrophobic interaction and van der Waals forces contribute to Nernst partition adsorption. Freundlich absorption had a greater contribution to total adsorption of yellow colorant on wool fabric, whereas partition adsorption imparted greater influence to colorant adsorption on silk and wool/polyester blend fabric. The pseudo-second-order model describes appropriately the dyeing process of wool, silk and wool/polyester blend fabric based on safflower yellow colorant materials. The thermodynamic parameters of dye absorption showed a significant difference. The absorption affinity (−Δμ°) of extracted safflower yellow dye on wool, silk as well as wool/polyester blend fabric indicated that the absorption is a spontaneous and exothermic process. So, safflower yellow colorant could be a good candidate as a natural green dye.

Antibacterial dyeing of silk with prodigiosins suspention produced by liquid fermentation

As a kind of natural dye, microbial pigments are attracting more and more attention for their application in textile dyeing. In this study, prodigiosins suspension produced by fermentation of Serratia marcescens was utilized as a novel kind of cleaner dye liquor for silk fabric dyeing. The average particle size of pigment particles was 217.1 nm and the prodigiosins concentration was determined to be 69.38 mg/L. Effects of technical parameters including dyeing temperature, dyeing time and dye liquor pH on dyeing effect and antibacterial capability of dyed fabrics were explored. The results indicated that when the dyeing temperature was 80 °C with a holding time of 30 min, dyed silk under dye bath pH 2.1 possessed high color strength, good color fastness and outstanding bacteriostatic rate of above 93.0% against Staphylococcus aureus. In addition, in vitro cytocompatibility test indicated that dyed silk fabric had no potential cytotoxicity to L929 cells. This study provided an innovative clean approach of dyeing silk with prodigiosins and endowed the fabric with antibacterial activity, simultaneously.

English

The evaluation and comparison of the staining effect of pomegranate (Punica granatum) flower extract (dye solution) on histological sections of rat testis and ovary provides a simple, quick technique for the visualisation of both cells. In the developed procedure, this work shows the staining effect of P. granatum flower extract used at different pH of dye bath and temperatures on the histological sections of rat testis and ovary. A 20% stock solution of P. granatum flower extract was prepared by dissolving 20 g of the dye in 100 mL ethanol at room temperature for several hours. After 24 h, the deep-red coloured solution was filtered (0.45 µm filter) to remove any undissolved dye. This stock solution was stored at room temperature and each day a 5 mL sample was taken and adjusted to different pH with dilute ammonia (NH3) using pH meter. Best staining effects conditions were obtained by testing the different pH of dye (1-2, 4-5) and temperature. The testis and ovary are stained in different colors; lamina propria section and spermatogonia cells of testis were more purple than the same sections of ovary at room temperature and pH of 1-2 dye bath. Therefore, the developed method has been applied successfully for the visualization of rat testis and not the ovarian tissue. Key words: Histological section, ovarian, pomegranate, Punica granatum, testis.

Studies on Dyeing Parameters of Colourants Extracted from Camellia sinensis

Wool and silk fibres have been effectively dyed with an aqueous extract of C. sinensis from an acidic dye bath (pH ~ 4.0). Methanol extract of the dye has been used for measuring different kinetic and thermodynamic parameters. The results indicate that the dye has an affinity for wool and silk. The standard affinity value of C. sinensis for wool fibre is greater than that for the silk fibre and it increases with the increase in temperature. Rate of dyeing for wool is lower as compared to that of silk. Studies on adsorption isotherm indicate that this dye is adsorbed on protein fibres chiefly following Langmuir adsorption mechanism.

Application of phenolic compounds as natural dye extracted from date-pits: dyeing studies of modified acrylic fibres

This research work involves the dyeing of acrylic fabric with natural dye extracted from date pits powders using Soxhlet extraction process. The effect of dye bath pH, salt concentration, dyeing time and temperature were studied. The optimal dyeing conditions where pH 4, 0 g/L salt, 60 min, and 80 °C. The COD and the BOD5 of the residual dye bath were measured and it was shown from the registered values that the residual dye bath presents an acceptable rate of organic discharge.

The use of D-optimal design in optimization of wool dyeing with Juglansregia bark

In this study, wool fibers were dyed using the Juglansregiabark as a new source of natural dye. Alum was used as mordant. Response surface methodology and D-optimal design were employed to study and optimize the dyeing procedure with the aim of obtaining the maximum color value after dyeing with aqueous extract of Juglansregiabark. The results showed that the color value of the dyed fibers was increased by increasing the dyeing time and temperature and decreased by increasing the dyebath pH value. There was an optimum value of around 6 % owf for mordant concentration. The optimal condition for obtaining the highest color value was as follows: dyebath pH: 6, alum concentration: 6.24 % owf, dyeing temperature: 90 ºC, and dyeing time: 90 min.

Microwave-assisted sustainable dyeing of wool fabric using cochineal-based carminic acid as natural colorant

ABSTRACTThe revival of natural dyes in textiles is gaining popularity due to their sustainable nature. The current study has been undertaken to improve the dyeing behaviors of cochineal-based natural dye (carminic acid) for wool dyeing under the influence of microwave treatment. For the purpose, wool fabric and extract obtained from cochineal insects (Dactylopius coccus costa) were irradiated for 1–6 min. The nature of dye bath (pH) and dyeing temperature were optimized using optimal irradiation conditions. To make dyeing process more sustainable and eco-friendly, bio-mordants and chemical mordants have been employed at optimal conditions. It is found that microwave treatment of extraction for 5 min is suitable to get darker shades with acceptable color characteristics using unirradiated wool fabric. K/S was found using acidic dye bath of cochineal insect of pH 1 for dyeing unirradiated fabric at 70°C using acidic extract of Cochineal bugs. Suggested ISO standards for color fastness revealed that 5% of henna and 3% pomegranate as bio-mordant have not only given high color depth but also rated excellent fastness properties as compared to chemical mordants used. It is found that MW treatment has not only improved the dyeing behavior of carminic acid but also enhanced the color characteristics.