Dyed Cotton Fabrics Research Articles

Characteristics of cotton fabric dyed with Euphorbia extract at different concentrations of cellulosic nanoparticles (CNP)

As the perception of the consumer's environment and the toxicity of synthetic dyes that is harmful to humans, interest in natural dyes is also increasing in the textile dyeing industry. This study performed an alternative to metal mordants and used cellulose nanoparticles (CNP) as a natural mortant for dyeing cotton fabrics with natural dyes extracted from Euphorbia. The characteristics with and without CNP mordant were investigated in the experiment. The effects of natural cellulosic mordants were analyzed through color, fastness, color, fastness, air permeability, antibacterial rate, UV protection, and total hand value (THV). As a result, the light fastness has been shown to significantly increase, but the improvements in terms of the wash, perspiration, and rubbing fastness were negligible. In addition, when CNP was added to cotton dyeing, there was no difference change in air permeability, but THV was significantly improved to 5 or more, and the UV protection and bacteria reduction rate were excellent. These results are attributed to the groundwork for studies on other types of natural dyes in the future and, by establishing the benefits of CNP, this study significantly contributes to the improvement of the end-products of dyeing.

Microwave-assisted sustainable exploration of cocklebur leaves (Xanthium strumarium L.) as a novel source of distinct yellow natural colorant for dyeing cotton fabric.

During current times, the use of bio-colorants attained public acceptance as a sustainable alternative to synthetic ones which in turn reduced the environmental contamination. The present study focused on the green, safe, and clean technology for the resurgence of natural colorant from cocklebur (Xanthium strumarium L.) leaves and their application to cotton fabric. Natural colorants were extracted by employing an eco-friendly microwave-assisted extraction process using an aqueous and alkaline medium. Dyeing of cotton fabric was carried out using irradiated and unirradiated cotton fabric with irradiated and unirradiated natural dyes of cocklebur leaves. The results of extraction experiments revealed that 4min microwave-assisted alkaline extract exhibited significantly outstanding color strength onto microwave-treated cotton fabric compared to aqueous one. Further to investigate the optimum dyeing conditions for cotton fabric, various dyeing variables such as dyeing time, dyeing temperature, dye concentration, and exhausting agent were monitored and found a superior result using a dye concentration of 45ml, for dyeing cotton fabric at 75°C for 50min in the presence of 4g/100ml of table salt. For improvement in color strength and color fastness properties, the effects of various bio-mordants, such as eucalyptus bark, acacia bark, turmeric rhizome, and onion shells, and chemical mordants (aluminum and copper) on dyed cotton fabric were also evaluated. It was also observed that cotton fabric dyed with alkaline extract of cocklebur leaves using bio-mordants as pre-mordants (4% acacia, 4% eucalyptus, 2% onion) and post-mordants (3% onion, 3% eucalyptus, 4% acacia) exhibited the highest color strength and various hues with acceptable colorfastness properties against light, washing, and rubbing in comparison to chemical mordants. The ISO standard for fastness also revealed that bio-mordanting has enhanced the rating from good to excellent in comparison to chemical mordants. The results provide ample scope for the extraction of yellow natural dye from the cocklebur leaves for eco-friendly coloration of fabrics using bio-mordants.

An ultrasound-assisted nitrogen protection system for sustainable indigo dyeing of cotton fabrics

The traditional process of denim dyeing is highly environmentally damaging due to high temperature used for reduction and dyeing as well as the heavy use of sodium dithionite. It can be efficient if dyeing can be carried out with an environmental reducing agent under nitrogen protection or if the liquor ratio can be reduced. However, at such a low liquor ratio, dye molecules form agglomerates, which results in inefficient dye-uptake and uneven dyeing. This study investigated the possibility of applying ultrasound in conjunction with nitrogen protection to the dyeing of cotton fabrics with indigo reduced by the reducing agent DK. Comparing the reducing agent DK with the other reducing agents, it was found that reducing agent DK had stronger reducing and better properties for indigo dyed fabrics. Furthermore, the synergistic effect of nitrogen protection and ultrasound prevented the early oxidation and agglomeration of the leuco-indigo. It was evident that there was an increased contact area between the leuco-indigo and the cotton fiber, as well as a decrease in the crystallinity of the cellulose macromolecules. And the increased amorphous region of the cellulose macromolecules facilitated indigo-leuco’s penetration into the fiber, resulting in enhanced dyeing depths and uniformity. In addition, orthogonal experiments and gray clustering analysis were utilized to optimize the dyeing process. As a result of the optimized dyeing process, the K/ S and S values of dyed denim fabric reached 16.70 and 0.12, respectively, which was 42% and 72% higher than the traditional sodium dithionite dyeing process. It was found that the dyeing liquid was more susceptible to biological and chemical degradation. In addition, the total economic costs were reduced by 11.702%. It is conceivable that eco-friendly dyeing strategies presented here have superior dyeing properties which can significantly enhance the sustainability of denim dyeing processes.

Green Application of Ultrasonic Waves for Extraction of Yellow Colorant from Haar Singhar and its Colouring Behaviour in Cotton Dyeing

Natural dyes have grown in popularity due to their eco-friendliness. They can be used as a substitute for synthetic dyes to minimize environmental pollution. This research investigates the natural colouring behaviour of haar singhar flower (HSF) extract in cotton dyeing. Colorant was extracted under various conditions utilizing various extraction mediums such as aqueous, basic, and acidic. On cotton, it was discovered that applying 55 mL of aqueous extract containing 1.5 g/100 mL sodium chloride for 40 minutes at 70 °C yielded the best colour output. A new hue with good colour fastness was developed utilizing chemical and bio-mordants. The existence of nyctanthin as a colouring agent in haar singhar flowers was discovered through FTIR analysis of the extract. The CIE Lab system revealed that using 2 g/100 mL of pistachio shell as a bio-mordant resulted in good quality reddish yellow hues. It was discovered that ultrasonic radiations have a high potential for isolating colourants and dyeing cotton fabric under decreased conditions of temperature, time and volume. The application of biomordants has made the procedure greener, more efficient, and safer.

Textile-Based Volatile Organic Compound Sensors Using Cellulose Fabrics and Direct Dyes

ABSTRACT In order to fabricate colorimetric textile sensors detecting gas phase of volatile organic compounds (VOCs), 11 kinds of direct dyes were investigated for 13 types of VOCs. Direct Violet 51 was chosen for its best sensing performance both instrumentally and visibly. Direct Violet 51 exhibited the change of color strength and color hue by exposure VOCs. The dyed cotton fabrics detected polar VOCs well, especially N,N-dimethylformamide (DMF). The colorimetric cotton-based textile sensor dyed with Direct Violet 51 exhibited approximately 10 of color difference (ΔE) under 10 ppm DMF gas within 100 min, and the maximum absorption wavelength was shifted from 560 nm to 530 nm. The sensing mechanisms could be summarized in three factors: solvatochromism and aggregative characteristics from the point of view of dye, and adsorption amount of VOCs for fabric. The colorimetric textile sensor retained its sensing performance after 10 cycle tests.

Extraction, Chemical Modification and Characterization of Turmeric Dye (Curcuma longa) and its Application on Cotton Fabric

Curcuma longa is a tropical plant whose rhizomes has been used to dye cloth since at least 2500 BCE but being a natural dye, it has poor to moderate fastness. In this study, an attempt was made to extract turmeric dye from Curcuma longa rhizomes and carry out its chemical modification by the choline chloride method to improve its fastness property when applied to fabrics. Turmeric dye was extracted from the rhizome using acetone and further crystallized with hexane to form the curcumin, the concentrated yellow dye. The characterization of the extracted dye and modified dye was carried out using Fourier Transform Infrared (FTIR) spectroscopy. Dyeing of cotton fabric was carried out using the extracted dye and the modified dye. Fastness properties was also determined on the dyed fabric. Fastness properties of natural Curcuma Longa dyed cotton fabric ranged from moderate [2] to good [4] and that of modified Curcuma Longa dyed cotton fabric ranged from good [4] to excellent [5]. This indicate that the modified fabric has better fastness properties. Dye manufacturing from local plants should be supported using chemical modification to achieve better fastness properties on dyed fabrics.

Fabrication of multifunctional cotton fabrics dyed with Coptis chinensis extract

Low dye exhaustion and poor colorfastness of cotton fabrics dyed with natural dyes were the inevitable issues, which may potentially limit their application in textile industries. Hence, there is great demand for improving dyeing performance of natural dyes to expand their application. This work presents a facile and efficient way to improve dye exhaustion and color fastness of cotton fabrics dyed with Coptis chinensis ( C. chinensis ) extract through fabric pretreatment and aftertreatment processes. The cotton fabrics were firstly treated with critic acid (CA) to increase their capacity of anionic sites. Enhanced effect of water repellent agent as the aftertreatment chemical, which was applied to improve washing fastness of dyed fabrics, was evaluated. The color characteristics, color fastness and functionalities of dyed fabrics were also assessed. The results indicated that pretreated cotton fabrics displayed higher color strength than the untreated fabrics. Additionally, the dyed fabrics treated with water repellent agents showed better washing fastness. The antibacterial activity of dyed fabric was increased up to 98% and the ultraviolet protection factor (UPF) value reached 349.69. What’s more, the dyed fabrics also exhibited excellent wrinkle resistance and waterproof property. The integration of antibacterial, antiultraviolet, antiwrinkle and waterproof properties in the cotton fabrics dyed with C. chinensis extract was a meaningful achievement, which exhibited great potential application in medical textile and garment. • Simultaneous dyeing and functional finishing were achieved by using C. chinensis extract. • Pretreatment of cotton fabrics with CA was beneficial for enhancing color strength. • Aftertreatment of dyed cotton fabrics with water repellent agent improve washing colorfastness. • The dyed cotton fabrics exhibit excellent multifunctional properties.

Eco-friendly dyeing of cotton fabric using used tea bag extracts: A comprehensive study on pH, fabric cationisation, and computational analysis

The present study aims to explore the eco-friendly dyeing of cotton fabric using extracts from used tea bags, without the need for any metal mordant. Additionally, this research delves into the intricate relationship between pH levels and fabric cationisation, exploring their combined impact on the functional properties of naturally dyed cotton samples. Preceding the dyeing process, the cotton fabric underwent cationisation through the application of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) at varying percentages. Subsequently, the fabric was dyed with tea liquor at different concentrations and pH levels. The ensuing investigation encompassed an assessment of color fastness and colorimetric attributes (CIELab, CIELch, ΔE, and K/S) of the dyed cotton fabrics. Furthermore, FTIR analysis was employed to augment our understanding of the dyeing process, while UV-Vis spectroscopy facilitated the quantification of exhaustion and fixation percentages. The results indicate that the highest exhaustion percentage of 88.6% was achieved at pH 13 for cationised fabric with a cationiser concentration of 55 g/L. In comparison, the non-cationised fabric exhibited an exhaustion percentage of 0.75%, while the mordanted (KAI(SO₄)₂.12H₂O) fabric showed 3.6%. Furthermore, the cationised fabric displayed excellent colour fastness to washing, rubbing, and perspiration (rated 4–5) compared to the non-cationised fabric. The stronger interaction calculated with density functional theory (DFT) between theaflavins, one of the primary colour components of tea dye, and cationised cellulose monomers explains the enhanced washing and rubbing fastness observed. The findings emphasize the significant influence of pH and fabric cationisation on dyeing and the functional properties of the dyed fabric.

Dying Properties of Natural Dyes Extracted from Parkia biglobosa Tree Bark on Cotton Fabric

The research work was carried out to extract natural dyes from Parkia biglobosa tree bark. Synthetic dyes are toxic, non-biodegradable and not friendly to the environment i.e. non-eco-friendly. Natural dye therefore perfectly fit into this since they are non-toxic, biodegradable, non-hazardous and more eco-friendly. Natural dye was extracted from Parkia biglobosa tree bark using Soxhlet extraction method and the dye extract was applied on cotton fabric. The percentage exhaustion, fastness properties and effect of mordant on the dyed samples was evaluated. The post-mordanting method was used to apply the mordant (potassium dichromate) on the samples. The dyeing of the samples were carried out based on the dyeing parameters such as dye concentration, electrolyte concentration, time and temperature respectively. From the result obtained, it was observed that the percentage exhaustion–quantity of dye absorbed by cotton fibre decreases with increase dye concentration. Similarly the absorption of dye was increased with the decrease of dye concentration. The highest percentage exhaustion of 96% was obtained at 10% dye concentration. However, it is observed, that increase in electrolyte concentration resulted increase in the percentage exhaustion. The highest percentage exhaustion of 61% was obtained at 10% electrolyte concentration. This observation is in agreement with the effect of electrolyte concentration on percentage exhaustion. From the result obtained, it was observed that the percentage exhaustion–quantity of dye absorbed by cotton fibre increases with increase in time of dyeing. The highest percentage exhaustion of 76% was obtained at 100 minutes dyeing time. It is obvious, from Figure 4 that the rate of dyeing increases gradually by raising the temperature. The highest dye exhaustion was attained at boiling (100oC). It may be suggested that the extracted dye in the aqueous medium is in aggregated form since they need an increase temperature to migrate into the fibre. In the effect of mordant on dye uptake and enhancement of fastness properties was evaluated from the result; it was observed that mordanting have improvement on the fastness properties. Comparing with the sample without mordant, post-mordanting have a better fastness property. However, on the whole, the mordant sample performs better. From the results it can recommended that dye extracted from Parkia biglobosa Tree Bark can be used to dye cotton fabric. The post-mordanted treated fabric samples have improved fastness properties when compared with non-mordanted fabric samples. The mordant also changed the shade of the dyed samples.

Dyeing Properties of Natural Dyes Extracted from Shea Butter Tree Bark (Vitellaria paradoxa)

The research was designed due to the recent renewed interest in the use of natural dyes for the dyeing of textiles as a result of the problem(s) associated with dyeing using synthetic dye. Synthetic dyes are toxic, non-biodegradable and not friendly to the environment i.e. non-eco-friendly. Natural dye therefore is a perfect replacement for synthetic dyes due to their non-toxicity, biodegradable, non-hazardous and more eco-friendly. Natural dye used for the study was extracted from Vitellaria paradoxa Shea butter tree bark using the Soxhlet extraction technique. The extracted dye was applied on cotton fabric and evaluated based on dyeing parameters such as dye concentration, electrolyte concentration, time and temperature. Mordanting was carried out with potassium dichromate using the post-mordanting method. The percentage exhaustion–quantity of dye absorbed by cotton fibres and the fastness properties of the dyed fabric were evaluated. From the result obtained, it was observed that the percentage exhaustion increases with increase dye concentration with the highest percentage exhaustion of 95% which was obtained at 8ml dye concentration. However, increase in electrolyte concentration resulted in increase in the percentage exhaustion with the highest percentage exhaustion of 98% which was obtained at 6ml electrolyte concentration. This observation was in agreement with the effect of electrolyte concentration on percentage exhaustion. It was also observed that the percentage exhaustion increases with increase in time of dyeing. The highest percentage exhaustion of 96% which was obtained at 3h dyeing time and for temperature it was observed that that the rate of dyeing increases gradually by raising the temperature. The highest dye exhaustion of 95% was obtained at the temperature of 50oC. It may be suggested that the extracted dye in the aqueous medium is in aggregated form since they need an increase temperature to migrate into the fibre. However, the application of mordant on the dyed samples improved the dye-fibre bonding and enhanced the fastness properties with colour change rating of 3 and 4 with shade of light brown. Comparing with the mordanted samples, the mordanted samples have a better fastness properties with colour change of 5 with shade of cork. However, on the whole, it can be recommended that dye extracted from Vitellaria paradoxa Shea butter tree bark can be used to dye cotton fabric.

Investigating the effect of microwave-assisted method in dyeing 100% cotton fabric using colorants extracted from fresh turmeric

Theresearchersinvestigatedthecurcumincolorantofturmeric,extracteddirectlyfromfreshturmeric.Investigating different dyeing conditions such as pH, dye concentration, microwave power, and dyeing time to determine the optimal conditions of a 100% cotton fabric dyeing process using a complementary dyeing method with microwave assistance. Optimal results were obtained with the following parameters: extraction ratio: 1:10, dyeing: pH 2–3, dyeing ratio: 1:30, dye concentration: 100%, microwave power at the level: high, dyeing time: 3 min and using 5% mordant CuSO4.5H2O. Washing fastness testing is a way of assessing the quality of dyed samples.

Investigating the effect of microwave-assisted method in dyeing 100% cotton fabric using colorants extracted from fresh turmeric

Theresearchersinvestigatedthecurcumincolorantofturmeric,extracteddirectlyfromfreshturmeric.Investigating different dyeing conditions such as pH, dye concentration, microwave power, and dyeing time to determine the optimal conditions of a 100% cotton fabric dyeing process using a complementary dyeing method with microwave assistance. Optimal results were obtained with the following parameters: extraction ratio: 1:10, dyeing: pH 2–3, dyeing ratio: 1:30, dye concentration: 100%, microwave power at the level: high, dyeing time: 3 min and using 5% mordant CuSO4.5H2O. Washing fastness testing is a way of assessing the quality of dyed samples.

Preparation and characterization of cationic soap-washing agent and its working mechanism for the removal of unfixed dyes for reactive dyed cotton fabrics

Preparation and characterization of cationic soap-washing agent and its working mechanism for the removal of unfixed dyes for reactive dyed cotton fabrics

Determination of The Effect of Dyeing and Finishing Processes on Physical, Mechanical, Handle, Comfort and Functional Properties of Cotton Knitted Fabrics

As it is known, the most widely used dye class for dyeing cotton fabrics is reactive dyes. However, the reactive dyeing process itself and various finishing processes applied after dyeing affects the physical, mechanical, handle, comfort and functional properties of the fabrics. Therefore, the main aim of this study was to determine the dyeing and finishing processes on the quality-performance characteristics of the cotton knitted fabrics. For this aim, physical (weight, wale/course density), mechanical (bursting strength, pilling, abrasion resistance), handle (bending rigidity), comfort (thermal comfort, air permeability, water vapor permeability) and functional (Ultraviolet protective functionality and flame retardancy of the fabrics) properties of fabrics were tested before and after dyeing and finishing processes. Fabric weight and bursting strength values increases after dyeing and finishing processes due to the shrinkage of the fabrics during wet processing. On the other hand, the pilling and abrasion resistance values ​​of fabrics are not significantly affected by dyeing and finishing processes. Another important result obtained is that the bending length and bending stiffness of the fabrics decrease after dyeing/finishing processes. The thickness values ​​of the fabrics decrease after dyeing-finishing processes and therefore the thermal resistance decreases. It was observed that the air permeability of the fabrics significantly decreased after dyeing-finishing processes. However, the water vapor permeability of the fabrics was decreased very slightly after dyeing and finishing processes. UPF ratings were increased after dyeing and finishing processes.
 Keywords: Cotton, dyeing, color, functionality, permeability

Development of Prediction System for Shade Change Variations in Dyed Cotton Fabric After Application of Water Repellent Finishes

ABSTRACT Textile finishing is the last stage to improve fabric aesthetic characteristic and impart functional properties, but at the same time it can produce some undesirable effects like shade change and variation in mechanical properties of fabric. These shade variations are undesirable and create major losses for the textile industry. These losses are related to rework and reprocessing of dyed fabric after finishing. To cope this issue, dyers are making decision on trial and error bases, therefore, this work has been conducted to quantify the shade change value. In this research work, an artificial intelligence-based system is developed to foresee the behavior of color before finishing. Color, shade percentage, finish type, finish concentration, and 31 reflectance values in the visible range 400–700 nm were selected as input for the training of artificial neural networks. The five networks were trained individually for the Δ color coordinates (△L, △a, △b, △C and △h). The networks were tested and cross-validated with 85% accuracy. The developed models were executed for the predictions of △L, △a, △b, △C, and △h with mean absolute errors 0.0765, 0.0869, 0.1528, 0.0829 and 0.1626, respectively. Mean absolute error values are showing a close correlation between actual and predicted values.

Investigating cotton dyeing using exotic wood waste sawdust

Investigating cotton dyeing using exotic wood sawdust. The study investigated the possibility of using extracts from various species of exotic wood, obtained from waste sawdust, for dyeing cotton fabrics. Material from Obeche, Iroko, Merbau, Apple tree, American walnut, Tulip tree, Cumaru and Rosewood were used for the tests. Solutions of oxalic acid, tin chloride, aluminum sulfate and ferric chloride were used as mordants, along with no-mordant tests. The color was determined in the CIE L*a*b* coordinate system. Color fastness was tested using n-hexane for dry cleaning and acidic, alkaline and hydrogen peroxide bleach solutions. The results showed a strong dependence on the type of wood, the mortar used and the washing agent and covered a wide spectrum of color intensity and fastness. The best results were obtained for Rosewood, Merbau and Apple trees, while Tulip tree and American walnut turned out to be practically useless. Among the mordants used, the most intense colors were produced by metal salts, including ferric chloride, which strongly darkened fabrics. Dry cleaning proved to be the mildest of those tested, with the least effect on color fading.

Employment of Imidazolium and Ammonium-Based Ionic Liquids to Enhance the Dyeability of Cotton Fibers with Reactive Dyestuff

In this study, the effect of ionic liquids on the dyeing of cotton fabrics with reactive dyestuffs was investigated. For this purpose, 100% cotton fabrics were treated with imidazolium (1-ethyl-2,3-dimethylimidazolium ethyl sulfate- E) and ammonium (methyl-tri-n-butylammonium methyl sulfate- B) based ionic liquids with three different concentrations. To assess the effect of the treatments, the cotton fabrics were characterized by FT-IR, SEM and DSC. After this treatment, the cotton fibers were dyed with 1.0% o.w.f reactive dye. The K/S values were determined to evaluate the effect of ionic liquids on the dyeability of cotton fabrics and fastness analyses to washing, water and rubbing were conducted to examine the end-use properties of dyed fabrics. The results revealed that ionic liquids settled on the fabric surface and after each ionic liquid modification, the increasing intensity was observed with increasing ionic liquid concentrations at broad bands according to the FT-IR analysis. It was determined that the K/S value of the modified cotton fabric increased with increment in the concentration of ionic liquid E, especially. Considering the overall results, it is possible to state that ionic liquids which are implemented in this study are efficient in enhancing the dyeability of the cotton fabrics.

Eco-friendly salt/alkali-free exhaustion dyeing of cotton fabric with reactive dyes

The textile-wet process enormously consumes a large volume of water and chemicals, and thus awareness of cleaner production has been growing to protect the environment from the industrial effluents. In this context, reactive dyeing of cellulosic materials such as cotton fabrics is a major sector of textile coloration that necessitates the use of a large amount of sodium sulfate or sodium chloride and alkali to exhaust and fix the dye molecules with cellulosic macromolecules, respectively. However, the remaining salt and alkali in the effluent badly affect the environment. For this purpose, the use of trisodium nitrilotriacetate (TNA) in reactive dyeing of cotton fabrics was hypothesized to have a double benefit, one as an exhausting agent (organic salt) and the second as a fixing agent (organic base). Thus, the exhaust dyeing characteristics of cotton fabrics using C.I. Reactive Yellow 145 (RY145) was optimized under different conditions of TNA concentration, alkali concentration, temperature, and dyeing time. The color strength and the primary and secondary exhaustion values were also investigated with an eye on those values obtained using the conventional dyeing method. The characterization of effluent samples with RY 145 taken after dyeing using TNA compared with conventional dyeing indicated an efficient reduction of COD, BOD, and TDS values by 99, 97, and 97%, respectively. The new dyeing method was implemented using C.I. Reactive Black 5 (RB5), C.I. Reactive Blue 160 (RB160), and C.I. Reactive Red 24 (RR24) to reveal good dyeability and fastness properties comparable with those obtained using the conventional method. The overall results obtained suggest the suitability of TNA as an environmentally friendly agent suitable as an exhausting and fixing agent of cellulosic fabrics.

Chemical Modification of Cotton Fabrics with Polyhexamethylene Guanidine for Salt-Free Dyeing with Reactive Dyes

ABSTRACT To realize clean dyeing of cotton fabrics, a new modification process was proposed. First, oxidized cotton fabrics were obtained by using 2,2,6,6-tetramethylpiperidin-1-oxyl radical and sodium hypochlorite in the form of selective oxidation. Cationic cotton fabrics were prepared by the Schiff base reaction between polyhexamethylene guanidine and oxidized cotton fabrics. The chemical structure and surface morphology of the modified cotton fabrics were analyzed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscope. Salt-free dyeing of modified cotton fabrics with four commercial reactive dyes was carried out, which was compared with the raw cotton fabrics dyed in the conventional dyeing. The result revealed that the color fastness of cotton cloth before and after modification was similar. The exhaustion rate and the total utilization of modified cotton fabrics increased by 20–30% and 30%, respectively. At the same time, the fixation rate reached more than 90%. In addition, mechanical properties of modified fabrics could be fully met with the application standard for dyed fabrics.

Optimization of Marigold Flower Dye Using Banana Peel as a Biomordant

ABSTRACT This research aims to optimize the dyeing process of marigold flower dye by using banana peel extraction as a biomordant in cotton fabrics. In the beginning, we investigated the optimal condition for extracting tannin compounds from fresh banana peel. Then, the woven cotton fabrics were dyed with marigold flower extraction at 90°C for 60 min with three different mordanting methods; pre-mordanting, post-mordanting, and meta-mordanting. With meta-mordanting, the ratios of mordant to dye solution were varied. The mordanting temperature and time of each methods were studied. The color strength, CIEL*a*b*, wash fastness, and light fastness were also inspected. It was found that the optimal condition for tannin extraction from the fresh banana peel was at 90°C, 1 h. When dyeing cotton fabrics with marigold flower dye by the pre-mordanting and post-mordanting method, the optimal mordanting condition was achieved at 60°C, 120 min, as the dyed fabrics showed the highest color strength. Moreover, the optimal condition of meta-mordant method was shown at 30°C, 90 min at the mordant to dye = 2:1 and 30°C, 60 min at the mordant to dye = 1:1 and 1:2. The color fastness of the mordanted cotton fabric was improved, especially the post-mordant method.