Natural Dyeing

The potential of the effluent waste produced in the distillation of eucalyptus leaves was evaluated as a natural material for the cotton dyeing. Selected physical-chemical parameters of the effluent and the concentrated were determined. The effluent and its concentrate showed acidic pH, and total solid content of, 3.4% and 48.1 % the content of condensed tannins, were 0.6% and 10.9%, respectively. The dyed fabric dye concentrations of 10 and 50%, based on the mass of the fabrics, had acceptable washing and light fastness according to test method CB-17, ABNT. After washing, the color change was evaluated as 3-4 for both concentrations. The multi-fiber fabric staining was greater than 4 for both concentrations. In the light fastness test, the color change was 2-3 and 3, at concentrations 10% and 50% respectively. The results showed that this solid waste has potential for cotton dyeing, with washing fastness properties acceptable by the textile industry. Further study is required to in...

Dyes derived from natural materials such as plant leaves, roots, bark, insect
secretions, and minerals were the only dyes available to mankind for the coloring of
textiles. Natural dyes per se are sustainable as they are renewable and biodegradable but
they cannot fulfill the huge demand from the textile sector in view of the preferential use of
land for food and feed purposes. Textiles colored with natural dyes are preferred by
environmentally conscious consumers and today there is a niche market for such textiles.
But the total share of natural dyes in the textile sector is approximately only 1 % due to
certain technical and sustainability issues involved in the production and application of
these dyes such as nonavailability in ready-to-use standard form, unsuitability for machine
use, and limited and non-reproducible shades. Also, overexploitation of natural resources
to obtain dyes may result in deforestation and threaten endangered species. This paper
attempts to review the current status of natural dyes and various sustainability issues
involved in their production and application and examines their future prospects.

The study was aimed to explore the possibilities for the utilization of water extract of fruits of Curry leaf tree as a source of natural dye for textile finishing. Fruit pulp of curry tree was at first hydrodistilled using Clevenger type apparatus to isolate essential oil. The left over water extract was used as dye for dyeing silk and wool fabrics. Solid content of water extract was determined in order to maintain the uniform dye concentration throughout the experiments which was recorded as 7.25% on moisture free basis. Silk and wool fabrics were dyed using common mordants like alum, copper sulphate, potassium dichromate, iron salts and tin salts with post mordnating technique. The material to liquor ratio (M:L) for dyeing of silk and wool fabrics was kept at 1:30, dye concentration 0.4% at temperature 95-980C and duration of dyeing silk and wool was 45 min. Mordanting was carried out using mordant solutions (0.5%) in distilled water. All the dyed and mordanted silk and wool samples were tested for their L*, a*, b*, C*, ho and K/S values. The outcome of the research work has led to the development of shades on silk and wool fabrics using curry tree fruit extract which is strikingly significant for the natural dyes sector.

The present study was undertaken to evaluate the antimicrobial activity of catechu in solution and % microbial reduction of dyed wool samples against Escherichia coli MTCC 443, Staphylococcus aureus MTCC 902, Candida albicans ATCC 10261 and Candida tropicalis ATCC 750, by using micro-broth dilution method, disc diffusion assay and growth curve studies. The dye showed the maximum antimicrobial activity at 20% w/v, inhibiting the microbial growth by more than 90%. In the next set of the experiments the antimicrobial activity of the dye was compared on woollen yarn alone and on pre-mordanted samples. The reduction in antimicrobial activity was observed when mordanted samples were examined. K/S, CIELab values and fastness properties of the dyed samples were assessed. The structural morphology of woollen yarn was also evaluated using scanning electron microscopy (SEM). Haemolytic activity on human erythrocytes was studied to exclude possibility of further associated cytotoxicity. The observed antimicrobial characteristics and negligible cytoxicity of catechu indicate that the dye might be a promising antimicrobial agent for developing bioactive textile materials and clothing.

In this study, plasma treatment and a poly(propylene imine) dendrimer were employed to improvethe dyeability of wool fibers with cochineal natural dye. FESEM, EDX, AFM and FTIR techniques wereemployed to investigate the effects of these treatments on chemical and physical properties of woolfibers. The etching of the surface layer of wool fibers and increased roughness after plasma treatmentwas confirmed by FESEM and AFM images. EDX and FTIR analyses confirmed the creation of oxygen-containing groups and attachment of dendrimer molecules on wool fibers after plasma and dendrimertreatments respectively. The effects of different dyeing parameters on dye absorption and the applicabilityof different isotherm and kinetic models on the dyeing process were investigated. The results showedthat the kinetics of absorption of cochineal on raw, plasma-treated and dendrimer-treated fibers wasbest fitted with the pseudo-second-order model and the isotherms of the dyeing processes followed theFreundlich model.

In this study, Berberis vulgaris L. wood as an agricultural waste was used for dyeing and functional finishing of
cotton. To facilitate the attachment of natural dye, citric acid was used to create carboxylic acid functional groups on cotton
fibers. The process of crosslinking of cotton fabric with citric acid was optimized in order to obtain the maximum dyeability
with the cationic natural dye. The effects of three important factors including citric acid concentration, sodium hypophosphite
concentration and curing temperature on the color strength of the dyed samples with woods of barberry tree were analyzed by
response surface methodology and the optimum conditions for obtaining the highest color strength was obtained. The
crosslinking of citric acid on cotton fibers was confirmed by FTIR spectroscopy. The dyed sample prepared under the
optimum conditions of crosslinking showed good wash and light fastness properties besides very good antibacterial activity
against gram-negative and gram-positive bacteria.

Chamba state of Himachal Pradesh was famous for embroidery known as pahari embroidery. The most popular article made was embroidered coverlets and hangings known as dhkanu (square coverlets) or chhabu (circular coverlets) used for covering the ceremonial gifts as well as offerings made both for gods and rulers (Sharma, 2009). In later centuries, unavailability of silk yarns and inappropriate use of colors adversely affected the quality of embroidered products. Hence, a sustainable approach was adopted to achieve the aesthetics of embroidery and to explore new possibilities under changed circumstances.  The study was undertaken to develop standardized recipes for dyeing base cloth and untwisted yarns used for embroidery in traditional color palette using natural dyes available locally. This would comprise of extraction, application of selected natural dyes on cotton fabric and silk yarns as well as testing of dyed material for color fastness properties. Natural sources of dyes that were easily available to the artisans in Chamba were selected for dyeing. Also, due to limitations of infrastructure available with artisans, ease and simplicity of application of dyes was of utmost importance. Bleached cotton fabric was dyed in a color used traditionally for embroidery. The shades developed for embroidery yarns were in line with those used in earlier times in 18th century. Dyed fabric and embroidery yarns were color fast to washing, dry cleaning and light. Intervention with the artisans was carried out by conducting interactive workshops and follow up field visits to Chamba. Interventions through workshops helped in capacity building of the artisans and proved invaluable. They helped the artisans to reorient themselves towards sustenance of the traditional form of craft.

KEYWORDS: Pahari embroidery, sustainable approach, extraction, application of dyes, color fastness test, intervention

In this study, cotton fibers were dyed with pomegranate rinds as a natural dye. To improve the dyeability of cotton fibers, chitosan was applied on the surface of the fibers. To enhance the application and adhesion of chitosan, oxygen plasma pretreatment was utilized. The procedure was optimized by response surface methodology and the most effective conditions for chitosan coating of cotton fibers, with the objective of obtaining the highest color strength, were found. The sample prepared under the optimal conditions was studied by scanning electron microscopy (SEM). The SEM images confirmed the existence of chitosan on the surface of the fibers. The chitosan-coated and naturally dyed samples demonstrated high antibacterial activity toward both gram-negative and gram-positive bacteria.

In this study, cotton fibers were dyed with pomegranate rinds as a natural dye. To improve the dyeability of cotton fibers, chitosan was applied on the surface of the fibers. To enhance the application and adhesion of chitosan, oxygen plasma pretreatment was utilized. The procedure was optimized by response surface methodology and the most effective conditions for chitosan coating of cotton fibers, with the objective of obtaining the highest color strength, were found. The sample prepared under the optimal conditions was studied by scanning electron microscopy (SEM). The SEM images confirmed the existence of chitosan on the surface of the fibers. The chitosan-coated and naturally dyed samples demonstrated high antibacterial activity toward both gram-negative and gram-positive bacteria.

In this study, wool fibers were dyed using the Juglans regia bark 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 Juglans regia bark. 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.

In this study, wool fibers were dyed using grape leaves. To improve the dyeability, wool fibers were pre-treated with
oxygen plasma. Response surface methodology and Box-Behnken design were employed to study and optimize the
plasma treatment with the aim of obtaining the maximum color strength after dyeing of the plasma treated samples with
aqueous extract of grape leaves. The surface of the raw and plasma treated samples were also studied by scanning
electron microscopy. The results revealed that plasma treatment has partially removed the surface scales of wool and
enhanced the penetration of the natural dye into the fibers. Plasma treatment power showed the highest effect on the
fiber modification and the optimum conditions for plasma treatment were indicated.

The annual European Textile Forum took place from 7-13 November 2016. This year the focus was 'mistakes', the unintended consequences in textile manufacture or preservation that reveal more about the artefact, the techniques used and its makers than a 'perfect' piece could do. The programme was rich in practical experiments, making use of the conference and laboratory facilities. There were lectures, workshops, roundtable discussions and a day's visit to the Römisch-Germanisches Zentralmuseum (RGZM) in Mainz. The forum is a place where academics, professionals, re-enactors, skilled amateurs and novices can meet to present new ideas and findings, compare notes, advise, reflect and learn new skills. The European Textile Forum is a proving ground for new theories in a friendly environment, organised by Katrin Kania and Sabine Ringenberg. Delegates could stay the length of the conference, a couple of days or use day passes to visit as they wished.

The potential of the effluent waste produced in the distillation of eucalyptus leaves was evaluated as a natural material for the cotton dyeing. Selected physical-chemical parameters of the effluent and the concentrated were determined. The effluent and its concentrate showed acidic pH, and total solid content of, 3.4% and 48.1 % the content of condensed tannins, were 0.6% and 10.9%, respectively. The dyed fabric dye concentrations of 10 and 50%, based on the mass of the fabrics, had acceptable washing and light fastness according to test method CB-17, ABNT. After washing, the color change was evaluated as 3-4 for both concentrations. The multi-fiber fabric staining was greater than 4 for both concentrations. In the light fastness test, the color change was 2-3 and 3, at concentrations 10% and 50% respectively. The results showed that this solid waste has potential for cotton dyeing, with washing fastness properties acceptable by the textile industry. Further study is required to in...

The potential of the effluent waste produced in the distillation of eucalyptus leaves was evaluated as a natural material for the cotton dyeing. Selected physical-chemical parameters of the effluent and the concentrated were determined. The effluent and its concentrate showed acidic pH, and total solid content of, 3.4% and 48.1 % the content of condensed tannins, were 0.6% and 10.9%, respectively. The dyed fabric dye concentrations of 10 and 50%, based on the mass of the fabrics, had acceptable washing and light fastness according to test method CB-17, ABNT. After washing, the color change was evaluated as 3-4 for both concentrations. The multi-fiber fabric staining was greater than 4 for both concentrations. In the light fastness test, the color change was 2-3 and 3, at concentrations 10% and 50% respectively. The results showed that this solid waste has potential for cotton dyeing, with washing fastness properties acceptable by the textile industry. Further study is required to in...

The potential of the effluent waste produced in the distillation of eucalyptus leaves was evaluated as a natural material for the cotton dyeing. Selected physical-chemical parameters of the effluent and the concentrated were determined. The effluent and its concentrate showed acidic pH, and total solid content of, 3.4% and 48.1 % the content of condensed tannins, were 0.6% and 10.9%, respectively. The dyed fabric dye concentrations of 10 and 50%, based on the mass of the fabrics, had acceptable washing and light fastness according to test method CB-17, ABNT. After washing, the color change was evaluated as 3-4 for both concentrations. The multi-fiber fabric staining was greater than 4 for both concentrations. In the light fastness test, the color change was 2-3 and 3, at concentrations 10% and 50% respectively. The results showed that this solid waste has potential for cotton dyeing, with washing fastness properties acceptable by the textile industry. Further study is required to in...

The annual European Textile Forum took place from 7-13 November 2016. This year the focus was ‘mistakes’, the unintended consequences in textile manufacture or preservation that reveal more about the artefact, the techniques used and its makers than a ‘perfect’ piece could do. The programme was rich in practical experiments, making use of the conference and laboratory facilities. There were lectures, workshops, roundtable discussions and a day’s visit to the Römisch-Germanisches Zentralmuseum (RGZM) in Mainz. The forum is a place where academics, professionals, re-enactors, skilled amateurs and novices can meet to present new ideas and findings, compare notes, advise, reflect and learn new skills. It is a proving ground to find and test new ideas in a constructive environment.

Color is one of the most useful and attractive characteristics of light applicable to optical science and the related industries. In recent decades, a number of studies focusing on the use of light as a key component of computation have attracted considerable attention from researchers and engineers because these studies are potentially applicable to signal processing through optical interconnections between electronic devices. Such studies include the optical parallel logic gates proposed by a Japanese research group, allowing spontaneous and parallel computing with spatial coding using lights, simply by overlaying a pair of shadowgram images. For computational handling of the colors visible to human eyes, Commission Internationale de l'Eclairge has defined CIE 1976 color space (CIELAB). The author has been engaged in the development of CIELAB-based printable and computable color codes possibly used for novel optical logic gate system as one of natural computing approaches. In the present study, by employing the pairs of CIELAB-coded-printed transparent films overlaid, a Boolean operation for the crossing (conjugation) of 2-by-2 color matrices based on the scanning of CIELAB values was demonstrated. This approach is still primitive but might be a significant step for manifesting the array-based processing of colors representing print-preserved and digitalized information .