Coloration Technology最新文献

The objective of the research was to evaluate the effect of mordants on colour variation, textile characteristics, colour fastness, and Fourier-transform infrared (FTIR) bands in alpaca fibre dyed with tankar stem extract. The white alpaca fibre was obtained from the company Inka Tops S.A. The mordants used were: alum (KAl(SO₄)₂·12H₂O) at 20% and iron(II) sulphate (FeSO₄) at 3%. Prior to dyeing, a pre-mordanting process was carried out (86°C for 30 min), and dyeing was performed through thermal treatment at 70 and 86°C (30 and 60 min). The CIELab [L*, a*, b*, chroma (C*) and hue (h°)] coordinates and reflectance were evaluated using a spectrometer; textile characteristics were assessed with OFDA (optical fibre diameter analyser) 2000; chemical bands were analysed with an FTIR-attenuated total reflectance (ATR) spectrophotometer, and colour fastness (light, washing, and rubbing) was evaluated using international American Association of Textile Chemists and Colorists (AATCC) standards. The results showed that luminosity (L*) significantly decreased after dyeing and pre-mordanting with KAl(SO₄)₂·12H₂O (81.47) and FeSO₄ (70.47). Additionally, the b* value and C* value significantly increased at higher temperature and longer dyeing time, resulting in slightly different shades and hues in each treatment. The coefficient of variation (CV) and curvature index (CU) presented significant differences, with CU increasing at 86°C/60 min with FeSO₄. Colour fastness to washing and rubbing showed acceptable values on the greyscale. In conclusion, the mordants used had a significant effect on colour variation, textile characteristics, colour fastness, and FTIR spectrum. The most intense shades were observed in fibres pre-mordanted with FeSO₄ (dull yellow-green) and in dyeing without mordant (yellow).

The textile industry is one of the significant reasons for global water pollution, with dyeing processes being particularly environmentally detrimental. Researchers have explored alternative approaches to address this issue, such as using natural dyes, supercritical fluids and so forth. In addition to environment-friendly approaches, reducing the number of experiments in studies, accurate production straightaway and using artificial intelligence (AI), one of the technologies of the present and the future that will provide significant support. Reaching clearer results with AI technology will not necessarily contribute to environment-friendly technologies. However, AI techniques, including artificial neural networks (ANNs) and adaptive neuro fuzzy interface system (ANFIS) were employed to predict the colour strength (K/S) of the dyed fabric based on process parameters. A comprehensive experimental design involving pressure, temperature, and time variations was conducted, and the results were analysed using multi-factor analysis of variance (MANOVA). The study demonstrates that supercritical carbon dioxide (scCO₂) dyeing with madder on polyester fabric is a promising and environmentally friendly approach. Additionally, the optimised ANN and ANFIS models, aided by genetic algorithms (GAs), exhibit high predictive accuracy (less than 3%), providing insights into the impact of process parameters on colour strength. This research underscores the potential of AI-driven automation in textile dyeing, offering solutions for dye formula prediction, colour matching, and defect detection, reducing the need for human intervention in these processes.

In this study, a polyamide warp-knitted fabric was treated with a graphene oxide (GO) aqueous dispersion using a laboratory-type Jigger dyeing machine. Subsequently, the GO underwent a chemical reduction process, employing rosehip extract powder as a nature-based reducing agent. The effect of reduction time (12 and 24 h) was investigated. The study involved an examination of the surface morphology, colour coordinates, and colour difference of both the GO coated and reduced graphene oxide (RGO) coated fabrics. Additionally, the colour fastness against rubbing was assessed. Furthermore, electrical resistivity measurements were conducted on the GO-coated polyamide-6,6 fabric both before and after the reduction process. The ultraviolet (UV) transmittance and ultraviolet protection factor (UPF) of both GO-coated and reduced fabrics were determined. The study also explored the effect of the washing process on colour properties, electrical resistivity, and UPF. Notably, the lowest electrical surface resistivity and the highest UPF rating were obtained as 1.20 × 10² kΩ/sq and 50+ after the reduction process. Additionally, after the washing process, the electrical surface resistivity increased, while the UPF rating remained 50+, indicating excellent UV protection.

Purple basil (Ocimum basilicum L.) extract has significant potential as a natural colorimetric pH-indicator material owing to its abundance in anthocyanins. This contribution is the first to optimise the ultrasound-assisted extraction of purple basil by response surface methodology in terms of maximum total monomeric anthocyanin (TMA) content and pH-dependent increase in green intensity (IGI) using a three-level, three-factor Box–Behnken design. The latter was considered as a measure of the pH-indicator ability of the extracts. The independent variables were ethanol concentration, solvent/solid ratio, and extraction time for two types of solvents [aqueous ethanol with 0.1% (v/v) acetic acid (Ac) or hydrochloric acid]. Optimum conditions were determined for single and combined responses. The extracts were further characterised according to total phenolic content (TPC), percentage polymeric colour (PPC), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) antioxidant, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities. All models explained more than 93% of the variability. The combined response model for the Ac-acidified system gave more favourable optimal conditions [55.25% (v/v) ethanol, 30 mL/g solvent/solid ratio and 39.24 min] regarding lower ethanol consumption and shorter times. Validation experiments verified the model successfully predicted the responses. The corresponding TMA, IGI, PPC, TPC, ABTS, and DPPH values were determined as 4.83 ± 0.18 mg cyanidin-3-glucoside equivalent, 2.29 ± 0.05, 68.07 ± 3.17, 28.79 ± 1.54 mg gallic acid equivalent, 55.85 ± 1.71 mg Trolox equivalent, and 16.80 ± 1.08 mg ascorbic acid equivalent per gram dry weight, respectively.

In order to solve the problems of poor dyeing properties and the colour fastness to ageing of poly(ethylene-vinyl acetate) (EVA) foam, good dyeing performance was obtained by disperse dye carrier dyeing method, and the colour fastness to ageing was improved by surface film forming. The effect of dyeing process on dyeing properties was investigated by the single factor variable method. The effect of film formation on colour fastness to ageing was also studied. The results showed that disperse dye carrier dyeing could significantly improve the dyeing depth of EVA foam. Addition of carrier and prolongation of dyeing time could significantly improve the colour strength (K/S) values and dye penetration. However, the increase of the dosage of dyes and the concentration of the carrier could lead to a serious decrease of the colour fastness to ageing of EVA. The colour fastness to ageing of EVA could be obviously improved by film forming on the surface. Waterborne polyurethane film-forming agent could improve the colour fastness to ageing by 1.5 grades, but the rubbing fastness was poor. When waterborne polyurethane and acrylate film-forming agent were compounded, the colour fastness to ageing and the colour fastness to rubbing could be improved.

Colour has been an indispensable element for humanity from past to present. Colour, which in the past was used only to add visual appeal and to differentiate from others, is now also used for various functional purposes (such as textiles that change colour with heat). The aim of this study is to investigate whether the fabric colour has an effect on the handle perception and warm/cool feeling of the user. Studies have shown that, in subjective evaluations, fabrics with warm colours (yellow, red and orange) cause softer and warmer feeling than those with cool colours (blue, green and purple). In fact, considering that there is no statistically significant difference between the handle and temperature values determined by objective test methods, it can be said that this perception may arise from the psychological effect of colour. All these results reveal that colour, beyond adding visual appreciation to the fabric, also has an effect on handle perception and warm/cool feeling, which play an important role in the purchasing process for customers.

In the modern period, scientists are interested in the functional properties of natural materials. The present study is the first report on the use of safflower (Carthamus tinctorius L.) yellow dye extract combined with chitosan bio-mordant for enhancing the anti-bacterial and ultraviolet-protective activities of silk. The presence of flavonoid-based compounds in the dye extract was verified using liquid chromatography–mass spectrometry, Fourier transform-infrared spectroscopy, and ultraviolet-visible techniques. Moreover, alum mordant was also utilised in the silk dyeing process to compare the efficiency of bio and metallic mordanting agents. Experiment outcomes revealed that the chitosan mordanted-dyed silk sustained adequate fastness after being tested by washing, light, wet-rubbing, and dry-rubbing. In addition, superb bacterial inhibition percentages of 89% and 76% against Escherichia coli and Staphylococcus aureus, individually, were accomplished. Furthermore, the ultraviolet-protective behaviour of this silk sample was demonstrated with a 50+ ultraviolet protection factor and low-grade ultraviolet transmittance. This study reveals the great performance of an organic flavonoid dye as a sustainable and environmentally-friendly substance for dyeing and functionalising silk, as well as the efficacy of a green mordant over a metallic mordant in increasing the dyeability and functional activities of silk.

Cotton/modal blended fabrics are favoured by the market because not only do they have the advantages of the dimensional stability of cotton and drape wear resistance of modal, they also overcome their shortcomings, displaying a sense of stiffness and smooth feel. However, because of the differences in the physical and chemical properties between each component, the dyeing of blended fabrics with reactive dyes is prone to problems such as low fixation percentage, different dyeing percentages and colour depth. Here, two cationic modifiers, 2,3-epoxypropyltrimethyl ammonium chloride (GTA) and methaacryloyloxyethyltrimethyl ammonium chloride (DMC), were applied for cationic modification of cotton/modal blended fabrics, and their role in the dyeability and union dyeing of cotton/modal blended fabrics was studied. The results showed that the K/S and fixation percentage of the blended fabric treated with GTA and DMC cationic agents could be significantly improved compared with the control group, and that the colour fastness of the blended fabric can reach grade 4-5. Compared with GTA, DMC-modified cotton/modal blended fabric showed better union dyeing properties because of its better diffusion performance in the fibre. The mesoporous volume of the cotton fibre is higher than that of the modal fibre, while the micropore volume is the opposite. Consequently, DMC macromolecules, through free radical graft polymerisation, were more likely to diffuse into cotton fibres with more mesoporous content, increased the interaction force between anionic reactive dye and cotton fibre, and improved the dyeability of the cotton component and the union dyeing performance of the blended fabric.

In this study, surface modification of wool fabrics by oxygen plasma was carried out to enhance colour, dyeability and fastness properties. Avocado (Persea americana) seed was selected as the natural dye source, plasma activated wool samples were dyed with the extracted colourant and tartaric acid (10% and 20% owf) was used for simultaneous mordanting. All samples exhibited very good washing and dry rubbing fastness grades. It was observed that plasma treated samples have darker and more saturated colours with a persistent hue and increased wet rubbing fastness grades. Applying plasma treatment and using tartaric acid as bio-mordant provided a noticeable increase in chroma and colour strength, and a slight improvement in fastness to light. Effect of pH of the dye bath on dyeability and the bio-mordant role of tartaric acid were also investigated for four mordant concentrations (2%, 5%, 10% and 20% owf), and it was detected that using 5% owf or higher concentrations of tartaric acid provided different colour characteristics and dyeability when compared to the dye solutions prepared with inorganic acid. Based on findings of the study, it was concluded that modifying the fabric surface by oxygen plasma can be used to enhance the dyeing performance without causing a major change in the characteristic hue of the colourant extracted from avocado seeds. The use of tartaric acid - solitary or accompanied with plasma treatment - to increase the affinity between the colouring matter and the fibre was also recommended.

Textile printing processes consist of the localised application of colour on textile substrates to obtain well-defined designs and patterns. Currently, there are many textile printing techniques; however, the limitations and selectivity of these techniques still keep the printing method of rotary screen printing the most important and used among them. One of the advantages of rotary printing is its excellent application versatility, which can be used for any fabric and non-wovens, fibre, or mixtures, with high production speed, quality, colour fastness, and definition. However, due to its high complexity, rotary printing requires great technical knowledge. Rotary printing requires specific application care depending on the fabric structure, fibrous composition, grammage, and type of intended effect. Regardless of the technique used, printed articles need to ensure that the colour remains attached to the substrate, either by direct dye–fibre or indirect pigment–binder–fibre bonding, to resist the conditions of use, that is, light, abrasion, stretching, and washing. The rise in recent publications reflects the search for economic and sustainable textile printing alternatives, focusing on screen printing variables. Based on this, this review aimed to present a comprehensive guide containing all the care and essential technical information for processes based on rotary printing.