Dyeing of Cotton Fabric with Natural Dye Extracted from Egyptian Cotton Leaves

Cotton leaves have been used to extract natural dye for dyeing of Egyptian cotton variety Giza 86 fabric and its blend with polyester 50:50, using different mordants such as iron (II) sulfate, copper (II) sulfate, and alum. The exhaust dyeing method was utilized using the pre-mordant technique. It is observed that both fabric samples can be dyed in different colors and depth of shades with Cotton leaves dye. Iron (II) sulfate ensures the best light fastness. Improved light fastness is obtained using abovementioned lower amounts of iron (II) sulfate and copper (II) sulfate. Alum is found to be less effective than iron (II) sulfate and copper (II) sulfate on the light fastness. As a novel alternative and potential natural dye, Cotton leaves extract solution can be used to get various colors and shades with satisfactory fastness properties. The mordanted and un-mordanted fabric samples were tested for their dyeing performance in terms of color parameters K/S, (L*), a*, b*, (C*) and (H*), and fastness properties (wash, perspiration, light and rubbing fastness) were studied. The samples showed high color strength, and high fastness properties. These results are very important for industrial application and with the production of a natural dye as an inexpensive source from cotton leaves as a by-product. Another objective is to increase the production of eco-textile garments with a good price for the Egyptian customers.

Adsorption-Kinetic Studies of Mordant Exhaust Dyeing of Cotton and Silk Fabrics with Dye Extract of M. lucida Plant Species

ABSTRACT The kinetics and adsorption isotherms of the extremely slow traditional natural exhaust dyeing that takes many hours or days have been studied purposely to find means of improving the process. The dyeing of cotton and silk fabrics using dye extract of M. lucida at 50 °C were elucidated with graphs to predict the reaction orders and identify the appropriate adsorption isotherm model(s). Since the dye is UV active, changes in UV absorbance were used in place of changes in concentrations. The simultaneous and post mordanting methods followed pseudo-second-order reactions, hence chemisorption. However, mordant application to the dyed fabrics during post mordant followed a pseudo-first-order model, largely physisorption. Dyeing has followed Langmuir and Freundlich isotherm models with linear correlation r2 ranging between 1 and 0.998. From the Freundlich model and values of Langmuir constant RL (0.9307 to 1.0), the process is homogeneous, forming a favourable and linear monolayer. Accordingly, the dyeing speed can be improved by increasing the concentration of dye liquor. Additionally, according to the Freundlich model, higher dye intensity on fabrics is recorded in post mordanting. Keywords: adsorption isotherms, equilibrium, exhaust dyeing, mordant, rate law

Dyeing of Polyester Fabric with Natural Colorants Extracted from Mahogany (Swieteniamahagoni) Seed Pods

Polyester fabric is usually dyed with disperse dyes which has severe limitations specially toxicity and environmental issues. The aim of the present research is to introduce an ecofriendly dyeing process for polyester fabric with natural dyes. The natural colorants were extracted from mahogany seed pods using the simple acid boiling method. The spectroscopic analysis of the crude extract was carried out by UV and IR spectra of the extracted dyes and illuminated the presence of natural tannins as coloring materials in the crude extract. 10g fabric was dyed in 200cc extracted solution at 130⁰C for 60 minutes in exhaust dyeing method followed by neutralization and soaping. Finally, a light brown dyed fabric was obtained. The dyed fabric exhibited color strength in terms of k/s value of 0.63 (λmax 360nm), lightness of 80.565 and chromaticity value of 12.002 CIE units. Different samples were dyed by fluctuating the dyeing period. The dyeing traits of the dyed materials were judged in terms of their color strength and fatness properties. All testes were carried out following the ISO standards. From the results, it is lucid that the dyed fabric showed acceptable color fastness properties in case of all fastness except color fastness to light. It is observed that dyeing time had profound influence on the color strength (k/s value) of the dyed material. The k/s value increases with the increase of dyeing period up to 120 minutes. The maximum color strength (0.76) was noted for the fabric. The shorter dyeing time produces lighter samples and the longer dyeing time produced colorful samples. Journal of Engineering Science 11(1), 2020, 37-42

Novel Approach to Dye Polyethylene Terephthalate (PET) Fabric in Supercritical Carbon Dioxide with Natural Curcuminoid Dyes

The use of natural dyes has increased in the last few decades due to the eco-friendly approach of dyeing. There are still some limitations that are associated with natural dyes, such as dyeing efficiency, reproducibility of shades, process complexity, availability etc. The main problem associated with the dyeing property of natural dyes is “low exhaustion”. In this study, natural dyestuff from Curcuma longa L. was extracted and polyethylene terephthalate fabric was dyed with it in the same bath by employing the supercritical carbon dioxide method. The method was developed to improve the dye-ability of natural dyes and reduce the process time and effluent. Curcuminoid dye exhaustion on PET fabric showed almost 80% by using supercritical carbon dioxide dyeing methods, and the highest colour strength (K/S = 12) was obtained. Coloured polyethylene terephthalate fabric treated with supercritical carbon dioxide showed deeper shades (L* = 72.92) and better fastness properties as compared with high temperature exhaust dyeing methods.

Application of foam dyeing technology on ultra-fine polyamide filament fabrics with acid dye

In this approach, the foam dyeing of polyamide filament fabrics with acid dye has been studied as a clean dyeing technology. The foam dyeing process parameters, including the blow ratio (BR), steaming temperature, time and humidity, were evaluated by color strength and color fastness. The results show that dodecanol and sodium carboxymethyl cellulose (CMC) mixed stabilizer could improve the foam stability and reduce the harm to human health. The optimum batch formula of dodecanol and CMC was 4:6. The K/ S value reached 3.58 at 11 BR, 100℃ steaming temperature, 20 min and 6.59% fabric moisture content. Compared with the exhaust dyeing process, foam dyeing can achieve the same level of color fastness with a higher K/ S value. These results suggest that foam dyeing is a simple and effective method for polyamide filament fabrics with acid dye, which can reduce the consumption of water, chemicals and energy, and accelerate production.

Synthesis of a Fluorescent Whitening Molecule and its Application to Wool Fibres

Aim and Objective: Reactive dye molecules are commonly employed to dye or modify colour characteristics of wool fibres. Yellowness of wool fibres poses a challenge and here, we report synthesis of a reactive fluorescent molecule and its application to wool fibres to reduce yellowness of the wool fibre and improve its colour features. Material and Methods: The new molecule was based upon 7-amino-4-methylcoumarin (AMC) and 2,4,6- trichloro-1,3,5-triazine (TZT). The synthesis involved a two-step chemical reaction, initiated by the nucleophilic substitution of a chloro group on the triazine ring with the hydroxyl group of 4-hydroxybenzenesulfonic acid. The substitution of 2nd chloro group at triazine ring with the amino group of 7-amino-4-methylcoumarin resulted in a novel molecule with a monofunctional reactive chloro group (AMC-MCT molecule). Results: The new molecule was applied to the wool fibres using exhaust dyeing method. This exhibited a high exhaustion value; however low fixation and total efficiency values were observed for the new molecule. The resultant wool fibres exhibited fluorescence which shows that aminocoumarin fluorophore retained its fluorescence when incorporated in the new molecule. An assessment of the molecule for yellowness index in a controlled exposure to UV radiation suggested an improvement in whiteness of wool fibre. Conclusion: A novel aminocoumarin based fluorescent whitening molecule 2 has been synthesised and applied to the wool fibres. The new molecule continued to exhibit fluorescence after its application to the wool fibres. These results will encourage researchers to explore further possibilities for reactive whitening agent for wool fibres.

Synthesis, Characterization and Dyeing Assessment of Novel Acid Dyes on Wool Fabric IV

We report synthesis and performance evaluation of a series of novel acid dyes based on diazotized substituted aryl amines and employing substituted naphthalene sulfonic acids as coupling component. The synthesized dyes were thoroughly characterized using UV-visible, IR, 1HNMR spectroscopy, elemental analysis and negative MALDI-TOF mass spectrometric analysis. The effectiveness of these dyes was evaluated by applying them on wool fabric using a standard exhaust dyeing procedure. The results for washing, light, perspiration and rubbing fastness of the dyed fabric demonstrate excellent fixation, binding strength and fastness properties which indicate that they are suitable for industrial wool dyeing operations.

Using of fluorinated aluminum silicate in the process coloring of textile materials with pigments

The aim of the work is to search for new drugs and technologies for processing textile materials to achieve high quality products with minimum costs and practical absence of harmful industrial emissions. Studies on the use of insoluble aluminum silicate in practical application in the textile industryare conducted at the Ivanovo State University of Chemical Technology. The experience of using silicates for modifying the properties of wool fibre and purification of exhaust dyeing solutions from direct, active and acidic dyes has been accumulated. The article considers the possibility of using fluorinated aluminum silicate (xAl2O3 * ySiO2 * zAlF3), which is a by-product in manufacture of aluminum fluoride, when coloring textile materials with pigment dyes. The uniqueness of this preparation lies in the fact that fluorinated aluminum silicate combines two fractions: insoluble (silicon and aluminum oxides) and soluble (aluminum fluoride). Aluminum fluoride has a limited solubility in water (0.41% by weight at 25 ° C), but is catalytically active and is used in a number of chemical processes as a catalyst. Due to the presence of water-soluble aluminum fluoride, fluorinated aluminum silicate has an acidic reaction. This powder is finely dispersed and its insoluble part has a white color, so it can be used as filler for blending printing inks and a catalyst for the dye fixing process on the fibre. The color and strength characteristics of the obtained stains convincingly prove that the fluorinated aluminum silicate can successfully replace commercially available catalysts. An additional positive feature is an increase in the shelf life of the finished printed composition. The limited solubility of aluminum fluoride, on the one hand, and its distribution in the structure of insoluble alumina and silicon oxides, on the other, makes the preparation catalytically inactive at room temperature, which positively affects the stability of the ink. Another option for the use of fluorinated aluminum silicate in combination with pigments can be purification of exhaust dyeing solutions. In this case, the high sorption activity of fluorinated aluminum silicate with respect to pigments plays a leading role. If fine dispersed fluorinated aluminum silicate is placed in the aqueous dispersion of the pigment, then, settling, it will capture the dye. Within 24 hours, the dispersion completely discolored. At the same time, the settled powder acquires a pigment tint. The results of the research presented in this paper make it possible to talk about the technological possibilities of using fluorinated aluminum silicate in the coloring of textile materials with pigments in which both its sorption ability and catalytic activity are in demand.

Application of Purified Lawsone as Natural Dye on Cotton and Silk Fabric

The color which is obtained from the leaves of Henna, that is, Lawsonia inermis L., is used frequently in hair coloring. It is the chemical lawsone that is responsible for the reddish brown color. Its content makes it a substantive dye for dyeing the textile materials. This work concerns with the extraction and purification of natural dyestuff from a plant Lawsonia inermis L. and dyeing of cotton and silk fabric in exhaust dyeing method. The dye portion is isolated from the total extract by column chromatography and is evaluated by dyeing cotton and silk under different dyeing conditions. The color strength and fastness properties of the dye are undertaken by changing mordant and techniques of mordanting. The changes of colors have been noticed by using different types of mordant. The dye exhaustion percentage, wash, rubbing, and light fastness results reveal that the extract of henna can be used for coloration of cotton and silk fabric.