The colour fastness of silk fabrics dyed with extracts obtained from the palm kernel shell (PKS) of African oil palm tree was evaluated at first in order to clarify the dyeing characteristics of this ...dyestuff. It was found in the colour fastness test to washing that the colour of the dyed silk fabric became deeper with the number of washing by basic Marseille soap solution and no fading occurred after up to thirty washings. The sample colour also became darker until 10 h of exposure to artificial sunlight illumination by a simulator and then brightened very gradually to 150 h in the colour fastness test to light. While the colour fastness to rubbing for the dyed fabrics was low under wet conditions, it was high under dry conditions. The PKS extracts contain the component substances which have reducing properties. Such unoxidised dye precursors are adsorbed onto the silk fabrics in the process of the dyeing and are oxidised to be colouring matters during the washing and light irradiation. On the other hand, attempts at colour stabilisation treatments to prevent darkening after dyeing by washing showed that treating the PKS-dyed silk fabric with Na2CO3·1.5H2O2 solution was the most effective. This treatment process oxidises the adsorbed component substances and prevents colour change due to the further oxidation. Furthermore, it was found that the colour of the PKS-dyed silk fabric turned black, very dark brown, brown or brown-close to black by the treatments with FeCl2, CuCl2, AlCl3 or VOSO4 aqueous solution, respectively. These are mordant effects by the metallic ions and post-mordanting was more effective in darkening the colour.
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.
Display omitted
•Ultrasound treatment improves fastness of sulphur dyeings.•In after-treatment combination of ultrasound treatment and soaping is most effective.•Improvement of wet rub fastness of ...C.I. Sulphur Black 1 about 1 grade was achieved.•Short treatment for 60 – 120 s allows integration in continuous dyeing.
C.I. Sulphur Black 1 is among the most important dyes for cellulose textiles, as this dye offers a maximum colour depth at reasonable costs. In its final form the dye is present as solid pigment, thus limited wet rub fastness can be an issue. Controlled re-oxidation of the leuco form into the oxidised dye pigment and intensive washing and soaping are measures to achieve acceptable wet rub fastness. In this study pad-steam dyeing with C.I. Sulphur Black 1 was used to investigate the effects of an intensified washing process with use of ultrasonification on rub fastness. Ultrasound was applied following to steam fixation of the dye. Introduction of ultrasound into the following process steps was investigated: water seal, warm rinse, oxidation, soaping, cold rinse. Best results in rub fastness were obtained by combination of soaping and ultrasound processing. The high shear rate near to the fibre surface led to a reduction of the thickness of the stagnant diffusion layer and more intense removal of loosely bound dispersed dye. As a result of the treatment an improvement in wet rub fastness of the dyeings was achieved. Duration of 60 – 120 s was found sufficient to remove the major part of surface bound pigments which allows an integration into continuous pad-steam dyeing processing. The results demonstrate that ultrasound washing may lead to improved rub fastness of other dyeings where a pigment is the final form of the dye. The method thus could be extended to vat dyes including indigo, or naphthol dyes.
The ability to add value to waste materials from industrial operations has come to the attention of the wood processing industry, with reports, for example, of extracts from the bark tree conveying ...colour and UV protection to textile fibres. The objective of the present work was to expand our developments in this arena by using
Desf. bark extract as a natural dye for textile dyeing. A complete 2³-statistical experimental design and the central point was elaborated. The results showed that the optimal dyeing conditions were 98 °C, for 60 min, using undiluted bark extract. The dyed fabric was analysed by a spectrophotometer using the CIELAB system for evaluation of the colour strength. The results showed a K/S value of 5.78, and the dyed fabric had good colour fastness to rubbing and washing.
New Mn(II), Ni(II), Co(II) and Cu(II) complexes of an azo dye ligand based on p‐phenylenediamine with 5‐nitro‐8‐hydroxyquinoline were synthesized and characterized using elemental analysis, inductive ...coupled plasma analysis, molar conductance, powder X‐ray diffraction, thermogravimetric analysis, magnetic moment measurements, and infrared, 1H NMR, electron ionization mass and UV–visible spectral studies. The spectral and analytical data reveal that the azo dye ligand acts as a monobasic bidentate ligand via deprotonated OH and nitrogen atom of the quinoline ring. The data support the formulation of all complexes with a 2:1 ligand‐to‐metal ratio, except the Mn(II) complex that has a mononuclear formula. All complexes have an octahedral structure. The molar conductance data reveal that all the metal complexes are non‐electrolytic in nature. From the X‐ray data, the average particle size of the ligand and its complexes is 0.32–0.64 nm. The colour fastness to light, washing, perspiration, sublimation and rubbing of the prepared ligand and its complexes on polyester fabrics and colorimetric properties were measured. The results reveal that the ligand and its complexes have a good to moderate affinity to polyester fibres.
New Mn(II), Ni(II), Co(II) and Cu(II) complexes of an azo dye ligand were synthesized. Spectral and analytical data revealed that the azo dye ligand acts as a monobasic bidentate ligand. X‐ray data for the investigated compounds were obtained. The colour fastness of the prepared ligand and its complexes on polyester fabrics and colorimetric properties were measured.
Colour fastness is one of the important characteristics, which depends on the further effective and rational use of the potential fabric resource, durability, wear resistance, and the level of ...competitiveness in the market. Therefore, evaluating the light fastness of colours of cotton fabrics, in the wear of which sunlight plays a major role, is an urgent scientific task. Chenille cotton fabric, which is currently in demand by textile decorators and modern interior decoration, was chosen for the research. The research was carried out using methods of visual and instrumental colorimetry. The conducted research is valuable for providing information to the market and for further analysis and implementation of the process of developing a system technology for designing chenille cotton fabrics.
The present study was conducted to explore the colouring potential of red calico {Alternanthera bittzickiana (Regel) G. Nicholson} leaves and to improve colour strength of dye using gamma radiations ...followed by mordanting process. The results showed that red calico plant leaves could be an excellent source of natural dyes for textile sector. Copper sulphate (1%) and tannic acid (1%) were the best pre- and post-mordants, respectively to improve the colour strength and colourfastness properties. The results from dyeing indicated that gamma ray treatment of 15 kGy was the effective absorbed dose for extraction of dye and surface modification of cotton fabric. Dyeing of cotton fabric with red calico leaf extract at 60 °C for 50 min using dye bath of pH 7.0 and salt concentration of 6 g/L produced good colour strength. Gamma ray treatment of cotton reduced the amount of mordants and improved the colourfastness properties.
•Natural dye from red calico leaves has been promisingly extracted using alkali medium.•Gamma ray treatment of 15 kGy improves the extraction of colourant and dyeing of fabric.•Gamma ray treatment also reduces the amount of mordants and time of dyeing application.•Optimum dyeing conditions: Temperature 60 °C, Dyeing Time 50 min, pH – 7.0, Salt Conc. – 6 g/L.
PDF
