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Todays, there is a strong tendency toward eco-dyeing with natural products. Several natural dyes have been used for dyeing protein fibers such as wool and silk fiber. This work examines the effect of metal mordant and biomordant on the color strength of dyed woolen yarn with madder, weld, and pomegranate natural dyes. The wool was mordanted with alum metallic and colorless mordant as well as walnut as colored and biomordant in pre-mordanting method. The madder, weld, and pomegranate natural dyes were extracted via ultrasound-assisted extraction (UAE). The woolen yarn was dyed with concentrations of 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100% WOF of natural dyes. The absorption behavior and dyeing properties of natural dyes were explored by measuring the reflectance spectra and colorimetric parameter of dyed samples. The spectral derivative method was used to analyze the reflectance spectra. The color strength of natural dyes was evaluated by measuring the K/S as reflectance function at λ max (SWL), SUM, WSUM, FK, KSgm, KSf, SKSf, and the first-order derivative of K/S spectra. The colorimetric study indicated that the color of the dyed woolen yarn changed with alteration of the mordant. The statistical analysis revealed that there were significant correlations between the first-order derivative of K/S spectra d1(K/S) as a new color strength parameter and other color strength parameters such as SWL, SUM, WSUM, KSf, SKSf, and color strength parameters. The obtained results indicated that the color strength of the natural dye with alum as metal mordant was greater than that of walnut as colored and biomordant. The study of fastness properties of dyed samples with madder and weld natural dyes showed that the wash and light fastness of the sample with alum mordant were better than those of walnut mordant. However, the samples dyed with pomegranate natural dye indicated that the wash and light fastness were the same for alum and walnut mordants. [ABSTRACT FROM AUTHOR]

Textile and dyeing are one of the most significant industries in many states. The employing of natural dyes in dyeing procedure is very important due to the environmental security of the area. To obtain a green, clean, and environmentally friendly dyeing of yarns, two natural dyes of madder and weld, which are native to Iran, were employed for dyeing yarns for carpet preparation. Due to the low affinity of natural dyes and maintaining the biocompatibility of the dyeing process, the oak was used as a new tannin rich mordant. The ultrasound-microwave-assisted method in water solution was used for extraction, and yield to the process was obtained about 27, 32, and 36% for madder, weld, and oak, respectively. The extractions were analyzed by UV–Visible and SEM techniques, and the ash, humidity, and density properties of these were investigated. The pre-mordanting method was employed for this study, and ferrous sulphate was used for compare of natural mordant performance. The washed, mordanted, and dyed yarns were investigated by analytical techniques, and the accuracy of these processes was confirmed. The fastness properties as well as the colorimetric characteristics of dyed yarns were assessed using related standards, and the dyed yarns have acceptable performance and could compete with metal mordant, colorimetrically. [ABSTRACT FROM AUTHOR]

Nowadays, using sustainable dyeing process has become a necessity, but does not meet performance requirements. Application of biomordants was recommended to enhance the quality of dyeing. Tannin-based biomordants appeared advantageous in green dyeing; meanwhile, unconditional affinity towards fibers of different types has attracted the attention of researchers. We introduce the idea of using combination of natural mordant as a new technique for sustainable dyeing of wool and a model natural fiber. In this study, Iranian madder was used as green dye and Yellow Myrobalan (YM) and Black Myrobalan (BM) employed as biomordant. FTIR-ATR spectra of the washed, mordanted, and mordanted-dyed wool fibers confirmed appropriate bonding among wool fibers, green mordant, and dye molecules. The superior color strength of wool fibers dyed with 4 %YM+6 %BM and 40 % madder was featured by K/S value of 35.77 and was obviously higher than that of madder by sumac, 9.5. Fastness properties (light, wash, and rub fastness) of wool dyed with combination of YM and BM were good. [ABSTRACT FROM AUTHOR]

This research paper is focused on the dyeing of silk fabrics with a natural dye extracted from Celosia flower and banana pseudostem sap as a biomordant. The dyeing process was carried out by three different techniques i.e. pre-, post-, and simultaneous mordanting method. The effect of dyeing process parameters namely mordant concentration, pH, and temperature on the dye absorption and fastness properties of dyed silk fabric have been investigated for each dyeing method. Optimal values of dyeing process parameters have been categorized based on the highest value of dye absorption in terms of K/S value. Optimum mordant concentration was found to be 18 % for all sets of dyeing methods. The optimum pH was examined to be 4.5, 4.0, and 4.0 and dyeing temperature was 70 °C, 70 °C, and 65 °C for the pre-, post-, and simultaneous mordanting dyeing methods, respectively. The color fastness to light, washing, and rubbing of dyed silk fabrics was investigated. Fastness values of light and rubbing showed fair-to-good fastness level, whereas the color fastness to washing was found to be good to very good. The antibacterial activity of the banana sap mordanted and simultaneously dyed silk fabrics was evaluated. The dyed silk fabric exhibited moderate antibacterial activity against gram-positive and gram-negative bacteria. [ABSTRACT FROM AUTHOR]

The current study is the first report of using biomordants with prina extract as a possible substitute for environmentally unfavourable metallic mordants. As a part of sustainable and cleaner production approach, eco-friendly natural dyeing conditions were presented in terms of cost and consumption efficiencies. A novel and renewable natural dye source prina is an essential by-product of olive oil production. This biomass was valorized in wool dyeing in conjunction with biomordants namely powder of iris germanica (I. Versicolor), valex (acorn of Quercus ithaburensis ssp.macrolepis), pomegranate (Punica granatum L.) rind, rosemary (Rosmarinus officinalis), and thuja (thuja orientalis). Their color coordinates and fastness properties were compared and assessed versus metallic mordants. Prina extract itself without mordant has a fair light fastness of 3 and an excellent washing fastness of 4-5 both for color change and bleeding. Valex, pomegranate rind, iris, rosemary, and thuja leaves were proposed as promising alternatives to alum, iron II sulfate, copper II sulfate, stannous chloride, and potassium dichromate. Biomordants generated significant color yield increment and exhibited equivalent fastness properties to metallic mordants. Water, energy, dye, chemical cost, and consumption of natural and synthetic dyeings on the basis of mill conditions were also calculated and compared mutually. Total recipe cost and chemicals/auxiliary consumption of natural dyeing are on average significantly less than with synthetic dyeing. Considerable savings are possible with natural dyeing, especially one-bath, in terms of cost, time, and consumption. [ABSTRACT FROM AUTHOR]

The classical use of synthetic dyes is causing issues of environmental pollution and heath risk. As a consequence natural dyes are gaining interest, but the use of natural dyes still includes toxic reagents such as metals as mordants and acids to enhance color and yield. Therefore, we designed a new chitosan-polypropylene imine dendrimer hybrid at 0-2000 mg/L to treat wool before dyeing with cochineal. We compared dye exhaustion, color depth, color characteristics, and color fastness of the new process with dyed pristine and metal mordanted wool. Results show that wool pretreatment improved dye exhaustion from 48 to 88 %, shifted saturation point toward lower dye concentration from 3000 to 1000 mg/L, and improved color depth from 13.68 for pristine wool and 15.17 for metal mordanted wool to 23.89 for the new process. [ABSTRACT FROM AUTHOR]

The triple bottom line can be impacted in both positive and negative ways by the use of tree sawmill waste as a natural dye. Trees contain a biomordant in the form of tannin which may eliminate the need for metallic mordants, thus reducing water, thermal energy, residual waste, and exposure to a mordant chemical. Dyeing with mill waste provides an economic option for an existing timber manufacturing byproduct. This research analyzed the impact of potassium aluminum sulfate (PAS) on dye concentration, hue, and colorfastness to light and laundering for three regional dyewoods (black walnut, Osage orange, and eastern redcedar) on wool yarn. Dye concentrations were pre-tested to find a standard depth of shade between mordanted and nonmordanted yarns. Tests for colorfastness to light and laundering were performed according to AATCC methods. Resulting colors for exposed and unexposed specimens were rated using CIE L*a*b* values and descriptive statistics were used to examine directional relationship within independent variables mordant and exposure (light and laundering). Two-sample t test was performed to investigate the effect of a PAS mordant versus no mordant on overall color difference between specimens exposed to light and laundering. Findings indicated that dye absorption was improved with the use of a PAS mordant. For yarns premordanted with PAS the dyewood colors became warmer. A PAS mordant slightly improved colorfastness to light for black walnut and eastern redcedar, but did not influence Osage orange which had a color change from bright yellow to warm brown after exposure to light. Colorfastness to laundering improved only for Osage orange with a PAS mordant. [ABSTRACT FROM AUTHOR]

In the present study, anthraquinone colorants were extracted from powdered Rubia cordifolia roots and applied on wool fiber. Acacia catechu is used as a biomordant, a replacement to metallic mordants, for wool dyeing, and the effect on color characteristics and fastness properties was assessed. Shades on wool of red tones with good to excellent color fastness properties were obtained. Pre-mordanting with A. catechu improved the overall color and fastness parameters, due to the maximum dye uptake. Auxochromic groups responsible for interaction of dye and wool were studied by Fourier transform infrared (FTIR) analysis of R. cordifolia extract. The surface morphology of dyed wool fiber was investigated by scanning electron microscopy (SEM) for any changes on fiber after dyeing. [ABSTRACT FROM AUTHOR]