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The aim of the present study is to evaluate the dyeing properties and behavior of the aqueous extract of Alnus glutinosa leaves when applied on cotton and wool fibers. The antioxidant activity and the total phenolic content of the aqueous extract were calculated. The colorfastness of the dyed samples such as washing, acid and alkali perspiration, wet and dry fastness and light fastness was performed. The ultraviolet protection factor (UPF) which is a measurement of the protection offered by the dyed fabric substrates against ultraviolet radiation was also assessed. It was found that Alnus glutinosa aqueous extract shows exceptionally high antioxidant activity and high phenolic content. The dyed samples showed astonishingly high light fastness approaching the light fastness of synthetic dyes such as the vat dyes or metal complex dyes. The conferred protection of the dyed samples against the distractive ultraviolet radiation is exceptionally high as this is demonstrated by the high UPF measurements of the dyed samples.

Cellulose diacetate fibers were prepared from cellulosic biomass with high α-cellulose contents such as purified cotton linters and wood pulps. Cellulose diacetate fibers are sensitive to alkaline solution, which causes hydrolysis of the acetate ester to hydroxyl groups, especially at high temperatures. Thus, the low alkali-resistance of cellulose acetate fibers makes it difficult to achieve high wash fastness by restricting the application of intense after-treatment, such as reduction clearing. A series of N-methylphthalimide-based high-washable azo disperse dyes were synthesized and their dyeing and fastness properties on cellulose diacetate fabrics were investigated. From the overall results obtained in this study, N-methylphthalimidylazo disperse dyes are expected to be a desirable alternative to high value-added dyes that can be used for high color fastness dyeing of cellulose diacetate with a minimal discharge of wastewater during washing process.

A novel self-colored waterborne polyurethane (SCPU) was synthesized and used in the preparation of a microfiber synthetic leather (MS-Leather) base in order to reduce the pollution caused by N,N-dimethylformamide (DMF) and dyes. The SCPU was prepared using the reaction of a reactive brilliant red K-2G with a waterborne polyurethane which was then extended via a first generation of hyperbranched poly(amine-ester). With the introduction of the dye, new absorption peaks at 1118 cm−1 [S=O], 1413 cm−1 [N=N], and 1635 cm−1 [C=N] appeared in the Fourier transform infrared (FTIR) spectrum of SCPU, and SCPU mean particle size increased to 162 nm. The X-ray diffraction (XRD) peak intensity of SCPU at 19.27° was 1310 cts. The thermal stability of SCPU at 200–280 °C was inferior to that of the control sample; however, it improved at temperatures above 360 °C. Finally, a free-dyeing MS-Leather base prepared by using SCPU without DMF was manufactured. It was found that the dyes were distributed mainly in the polyurethane matrix rather than in the microfibers. Moreover, the color changes of the base before and after being washed in both a water and a soap solution were 0.93 and 4.21, respectively. This indicated that the base’s washing color fastness to water was better than to a soap solution.

The interest in pH-sensitive textile sensors is growing in the global market. Due to their low-cost production, mechanical stability, flexibility, air-permeability, washability, and reusability, they are more suitable than electronic sensor systems. The research tailored the pH-sensitive textile by applying the pH indicator methyl orange to the cotton fabric during conventional dyeing. Adsorption of methyl orange dye to cotton fabric is hindered due to electrostatic repulsive forces between dye anions and negatively charged cotton fibre. To overcome this problem, chemical modification of cotton fabric using a commercial product was performed. The pH sensitivity of the dyed fabric was spectrophotometrically evaluated. In addition, the colour fastness of dyed cotton fabric to washing, light, hot pressing and rubbing was investigated according to valid SIST EN ISO standards. The research results show that the pH-responsive cotton fabric was successfully developed. The chemical modification of cotton fabric is crucial for the increased adsorption of methyl orange dye. The halochromic effect was not only perceived spectrophotometrically but also with the naked eye. The developed halochromic cotton fabric showed poor colour fastness to light and good colour fastness to hot pressing and rubbing, while no significant improvement in colour fastness to washing was observed, even though the fabric was after-treated with a cationic fixing agent. Higher adsorption of the methyl orange dye to the cotton fabric during the dyeing process leads to less wastewater pollution after dyeing with unfixed dye and, thus, a reduction in wastewater treatment costs.

The resurgence of natural dyes is gaining fame in textile industry due to eco-friendly nature. The present study was done to investigate the Coconut coir as natural dye (tannin) for silk dyeing under Microwave (MW) treatment following the optimization of experimental parameters. Isolation of colorant was carried out in aqueous, acidic and organic media (methanol) under influence of MW treatment up to 6 minutes. Dyeing of silk was carried out having irradiated and unirradiated extracts. Good colour strength was achieved by dyeing unirradiated silk using methanolic extract under MW treatment for 4 minutes at 75°C. The optimal dyeing was achieved at 75 minutes at pH 8 while keeping fabric liquor ratio 1:25 having 5 g/100 ml table salt as an electrolyte. For development of shades, salts of Al and Fe and Tannic acid were used as pre- and post-chemical mordants and Acacia, Pomegranate, Turmeric and Henna as pre- and post-biomordents. Acacia (6%) as pre-bio mordant and Turmeric (6%) as post-bio mordant considerably improved the colour strength at optimal conditions utilizing irradiated extract of coconut coir (tannin) and un-irradiated silk under MW treatment at 4 minutes. ISO-standard shows good colour fastness and colour strength at optimal conditions using Acacia and Turmeric as bio-mordents. This research work gives information about tannin extracted from Coconut coir has great potential to dye silk fabric to produce reddish-brown colour under the influence of microwave treatment. FTIR spectral study revealed chemical changes in the silk fabric treated with microwave radiations.

Purpose The purpose of this study is to extract and characterize a novel natural dye from the leaves of Lannea coromandelica and the extraction with finding ways of dyeing cotton fabric using three mordants. Design/methodology/approach The colouring agents were extracted from the leaves of Lannea coromandelica using an aqueous extraction method. The extract was characterized using analysis methods of pH, gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared (FTIR), ultraviolet-visible (UV-vis) and cyclic voltammetry measurement. The extract was applied to cotton fabric samples using a non-mordant and three mordants under the two mordanting methods. The dyeing performance of the extracted colouring agent was evaluated using colour fastness properties, colour strength (K/S) and colour space (CIE Lab). Findings The aqueous dye extract showed reddish-brown colour, and its pH was 5.94. The GC-MS analysis revealed that the dye extract from the leaves of Lannea coromandelica contained active chemical compounds. The UV-vis and FTIR analyses found that groups influenced the reddish-brown colour of the dye extraction. The cyclic voltammetry measurements discovered the electrochemical properties of the dye extraction. The mordanted fabric samples showed better colour fastness properties than the non-mordanted fabric sample. The K/S and CIE Lab results indicate that the cotton fabric samples dyed with mordants showed more significant dye affinities than non-mordanted fabric samples. Originality/value Researchers have never discovered that the Lannea coromandelica leaf extract is a natural dye for cotton fabric dyeing. The findings of this study showed that natural dyes extracted from Lannea coromandelica leaf could be an efficient colouring agent for use in cotton fabric.

The behaviour of textile products made from different fibres during finishing has been investigated by many scientists, but these investigations have usually been performed with cotton or synthetic yarns and fabrics. However, the properties of raw materials such as linen and hemp (other cellulose fibres) and linen/silk (cellulose/protein fibres) have rarely been investigated. The aim of the study was to investigate and compare the mechanical (breaking force and elongation at break) and end-use (colour fastness to artificial light, area density, and abrasion resistance) properties of cellulose and cellulose/protein woven fabrics. For all fabrics, ΔE was smaller than three, which is generally imperceptible to the human eye. Flax demonstrated the best dyeability, and hemp demonstrated the poorest dyeability, comparing all the tested fabrics. The colour properties of fabrics were greatly influenced by the washing procedure, and even different fabric components of different weaves lost their colours in different ways. Flax fibres were more crystalline than hemp, and those fibres were more amorphous, which decreased the crystallinity index of flax in flax/silk blended fabric. Unwashed flax fabric was more resistant to artificial light than flax/silk or hemp fabrics. Finishing had a great influence on the abrasion resistance of fabrics. The yarn fibre composition and the finishing process for fabrics both influenced the mechanical (breaking force and elongation at break) and end-use (area density and abrasion resistance) properties of grey and finished fabrics woven from yarns made of different fibres.

The aim of the study was to analyse the colour fastness of 3D printed samples that could be used as decorative or household items. Such items are often fabricated with 3D printing. The colour of filaments affects not only the mechanical properties, but also the appearance and user satisfaction. Samples of biocomposite filaments (PLA and PLA with added wood and hemp fibres) were used. First, the morphological properties of the filaments and 3D printed samples were analysed and then, the colour fastness against different agents was tested (water, oil, detergent, light and elevated temperature). Finally, the dynamic mechanical properties of the filaments and 3D printed samples were determined. The differences in the morphology of the filaments and 3D printed samples were identified with SEM analysis. The most obvious differences were observed in the samples with wood fibres. All printed samples showed good resistance to water and detergents, but poorer resistance to oil. The sample printed with filaments with added wood fibres showed the lowest colour fastness against light and elevated temperatures. Compared to the filaments, the glass transition of the printed samples increased, while their stiffness decreased significantly. The lowest elasticity was observed in the samples with wood fibres. The filaments to which hemp fibres were added showed the reinforcement effect. Without the influence on their elasticity, the printed samples can be safely used between 60 and 65 °C.

Cotton fabrics were double pre-mordanted with natural potash alum and tannin-rich gallnut (Quercus infectoria), acting in combinations as dual-bio-mordants for dyeing it with tannin-rich catechu natural dye extract. This study confirmed that K-Alum and gallnut dual-bio-mordanting, followed by dyeing it with catechu extract, formed a bigger giant water-insoluble complex of [Cotton-Al-Gallo-tannins-Catechin] and produced an orangish brown colour shade on cotton. The said dual pre-mordanted cotton using overall 15% [K-alum+gallnut in 75:25 proportion], applied one by one in the sequence, was found to offer maximum colour strength (K/S 12.19 and average to good colour fastness to wash, UV–light, and rubbing, improving 1/2 to 1 grade. Finally, all the conditions of dyeing parameters were standardised for the said overall 15% (K-Alum+Gallnut in 75:25 ratio) dual-pre mordanted cotton fabrics for dyeing with catechu and the standardised dyeing conditions found are––30% concentration of catechu extract, pH 4.0 for dye bath, 1:20 MLR, 60 min time of dyeing and 70 °C temperature of dyeing and 5gpl salt concentration, to obtain maximum colour strength up to 12.19 with CV% of K/S within 5% indicating more uniform colour. Moreover, a good degree of bacterial reduction up to 80–85% and a reasonable degree of UV–resistant properties, UPF value up to 30 can be achieved, for such 30% catechu-dyed cotton after overall 15% K-alum and Gallnut (75:25) dual pre-mordanting. Further 10% aqueous extract of Eucalyptus leaves applied as a bio-finish by pad-dry-cure process do not alter the colour strength much, but bacterial reduction is improved up to 90–95% with UPF value improved up to 40. This work is thus considered useful for producing uniform, reproducible deep shades for such catechu dyed cotton fabric-based medical textiles for use in improving the wellness behaviour of human wearers.