Coloration Technology最新文献

Natural plant extracts have been used for dyeing textiles since prehistoric times. With the discovery of synthetic dyes in 1856, the consumption of natural dyes declined sharply. However, the current focus on closed-loop systems, the circular economy and the promotion of sustainable industries aimed at reducing environmental impact (eg, The European Green Deal) has led to a renewed interest in plant-based dyes, along with an exploration of their applications, advantages and creative potential. In this study, we successfully integrated locally sourced plant-based dyes (flowers: golden tickseed, marigold, peony; berries: holly-leaved barberry, five-leaved ivy; leaves: ivy, birch, strawberry; and husks: English walnut, yellow onion) into screen-printed patterns. We focused on determining the photochemical and thermal stability of dyed products, complemented by live testing. Two types of commercially available tannins and three types of mordants on eight fabric types were used to investigate the colour gamut and creative possibilities of individual iterations. By applying the “intentional imperfection” design method, which results in dynamic and evolving patterns, the study embraced the inherent variability of natural colourants rather than forcing them into conventional, highly controlled manufacturing processes. The modulation of printing technique, incorporating deliberate imperfections, was explored to develop more stain-resistant and user-oriented designs open to subsequent modification through re-dyeing. This approach enhances the retention of the textile during the active stage of the product lifecycle and demonstrates its potential to contribute positively to the overall sustainability of the product.

In recent years, the design discipline has faced increasing pressure to adopt sustainable practices that address the environmental, social and ethical challenges of production. Colour design plays a pivotal role in influencing consumer behaviour, resource consumption and waste generation, yet it remains an underexplored area in sustainable design research and education. This article presents the development and peer review of the Sustainable Colour Design Strategies (SCDS) framework, a tool designed to guide designers, educators and industry stakeholders in making informed, sustainable colour decisions. The framework comprises eight strategies and 40 concrete actions, addressing key themes such as fostering a sustainable colour mindset, integrating colour circularity, embracing local identity and promoting bio-colour innovations. The SCDS framework was developed from a research-through-design approach, using a qualitative methodology combining systematic literature reviews to identify gaps, the analysis of 65 case studies to understand sustainable practices, stakeholder interviews and peer-review feedback to highlight the framework's potential to bridge the gap between theory and practice, emphasising its applicability in design education, industry and policymaking. By positioning designers as system thinkers, the framework supports interdisciplinary collaboration and innovation. This study contributes to advancing the discourse on colour sustainability, calling for its integration into design curricula and industry practices to promote a more sustainable, regenerative future for colour design.

The use of natural dyes has become increasingly important as a result of their lower environmental impact and health benefits. However, developing eco-friendly dyeing processes and auxiliary products that maintain high chromatic quality remains a challenge. Natural indigo dye exemplifies this issue, as traditional industrial reduction methods using agents such as sodium dithionite are associated with significant environmental pollution. This study explored the application of fructose as a sustainable reducing agent for dyeing cotton fabrics with indigo extracted from the Indigofera tinctoria plant, adapting an artisanal process to industrial equipment. The most effective method involved a single-stage vat dyeing process conducted at 60°C for 60 minutes, using a 1-2-3 formulation. Results indicated that fructose emerges as an effective and environmentally friendly alternative in an industrial process compared with conventional toxic reducing agents. The study also evaluated the effect of different non-toxic auxiliary products and mordanting techniques. Pre-mordanted samples exhibited more saturated colours than post-mordanted; however, wash fastness results were lower. For example, gallnut used in the pre-mordanting process produced dark tones but showed noticeable colour change after washing, while post-mordanted samples achieved higher wash fastness. The integration of diverse auxiliaries in separate dyeing processes expanded the colour spectrum beyond the conventional blue typically associated with indigo dye, introducing a range of unique shades and hues. This study contributes to the recovery of traditional knowledge, incorporating more environmentally friendly products and adapting them to industrial equipment, while exploring a diverse chromatic palette. Such innovation supports fashion designers in creating distinctive and environmentally responsible collections.

Coloration is a key feature in the textile industry that adds value to the final apparels. This coloration of textile products is done by conventional methods which involve huge amounts of water pollution and wastages of textile colourants. Several approaches have been taken to eliminate these issues by advanced dyeing methods, however, due to process complexity advanced dyeing methods are still inconvenient on an industrial scale. Recently, involvement of nanotechnology via nanofibre or nano-colourants has drawn attention to the textile coloration field as these approaches are feasible with conventional textile coloration methods. Adding to that, reducing the wastage of textile colourants and wastewater pollution, and enhancing colour strength and better colour fastness properties by applying nanotechnology in coloration opens new dimensions. Previously, some studies have been done on nanofibre synthesis methods and application of nano-chemicals for enhancing the functional properties, but less attention has been put on textile coloration efficiency enhancement by applying nanofibre or nano-colourants. Therefore, this study emphasised on discussing nanofibres and nano-colourants synthesis by different approaches for textile purposes, dye–fibre interaction during textile coloration, and their impact on textile coloration performances—how those nanomaterials enhance the colour appearance and durability in textile fabrics, and the challenges that needs to be considered for bulk textile coloration.

One of the most important analytical techniques in spectral data analysis is derivative spectrophotometry. This technique can increase the signal-to-noise ratio in the qualitative and quantitative analysis of multi-component samples. The appearance of the derivative spectrum, such as height, width and distance between the maximum peaks, changes with the derivative order. Additionally, derivative spectrophotometry has been used to analyse overlapping spectra of multi-component samples, improve the resolution of overlapping peaks and remove the background as noise. Derivative spectrophotometry has been applied to analyse infrared spectra, fluorescence spectra and ultraviolet–visible spectra data. The five most used methods are peak-zero, zero-crossing point, peak-peak-ratio, peak-tangent and ratio of spectra. The concentrations of coloured components in binary and ternary mixtures of dyes were estimated using peak-zero, zero-crossing point, peak-peak-ratio and ratio of spectra derivative spectrophotometry. The derivative method has been used in several scientific fields, such as characterisation of pigments, characterisation of colourants, identification of pigments in artworks, realistic texture reconstruction of an artwork, characterisation of dyes in ancient purple codices, quantitative analysis of mixed pigments, identification of natural polymers and resins in paintings, determination of food dyes, characterisation of paintings, identification of artists' materials, identification of the natural dyes and identification of pigments. The derivative method has also been applied in the textile industry, including fibre identification, prediction of dye concentrations in solution, analysis of dyes in wastewater, analysis of natural dyes and dyeing recipe prediction.

Polyhydroxyalkanoates (PHAs) are a class of biopolymers produced by various microorganisms, with poly(3-hydroxybutyrate) being the most extensively studied. PHAs are widely studied as substitutes for conventional plastics due to their similar physicochemical properties. However, the production cost of PHAs remains high. In this context, the use of colours in biopolymers is a marketing tool that plays a significant role in influencing consumer purchasing behaviour. Therefore, the aim of this study was to review, analyse and compare different methodologies for colouring PHAs published to date. Studies reported various methods for colouring PHA films, which were classified into two main methodologies: (i) simultaneous synthesis and colouring of PHAs; and (ii) production and colouring of PHAs in different stages. The analysis revealed that the field of PHA colouring is still under-explored, with relatively few studies conducted to date. Further research is required to optimise the production processes for coloured biopolymers. Additionally, there is a need to investigate new classes of natural dyes for colouring PHA films and their application in innovative, environmentally sustainable products, such as intelligent and biodegradable packaging. This review article is the first to systematically assess the methodologies for colouring PHA films.

Conventional textile dyeing utilises large amounts of water and generates significant amounts of wastewater, highlighting the need to utilise more sustainable dyeing methods. Supercritical carbon dioxide (scCO₂) dyeing offers a zero-water, zero-wastewater alternative with reduced energy requirements and carbon dioxide recyclability. While both conventional and scCO₂ dyeing commonly rely on synthetic (petroleum-based) dyes, incorporating natural dyes could enhance the sustainability of scCO₂ dyeing by reducing dependence on non-renewable resources. Thus, this study evaluated alizarin, an aglycone anthraquinone dye from Rubia tinctorum L. (madder plant), in scCO₂ without any mordant or auxiliaries. Alizarin was selected for its historical significance, colour intensity and colour stability. Its performance was compared with two additional madder-derived compounds, the glycosides ruberythric acid (RA) and lucidin primeveroside (LP). Dyes (0.5%, 1% owf) were applied to polyethylene terephthalate (PET) at 120°C and 34 MPa for 60 minutes. Findings indicated that only deglycosylated dye (aglycone) exhibited high uptake (≥65%), while RA/LP exhibited a lower uptake (27.1% ± 2.7%) on PET due to their hydrophilicity. Indeed, alizarin exhibited higher uptake on both PET and recycled PET (r-PET) fibres in scCO₂, with a maximum uptake of 95.7% ± 4.3% exhibited on r-PET. Furthermore, alizarin uptake on PET using scCO₂ as the dyeing medium was comparable to or higher than that achieved with water. Dye uptake, colour and fastness properties were also comparable to those of C.I. Disperse Yellow 54, a synthetic dye.

Recent global interest in sustainable practices in the textile and fashion industry has inspired stakeholders to readopt natural colourants. However, integrating these practices raises several questions regarding the latest developments in natural colourant and trend forecasting practices in the textile and fashion industry. It also prompts inquiries about how to incorporate the use of natural colourants into current industry, and the role of the trend forecasting industry in this. Colour decisions, first in the fashion design process, are influenced by the designer's creativity, forecasted trends and factory capabilities. A systematic literature review was conducted to examine the latest developments in natural colourants and trend forecasting for the textile and fashion industry. This was compared with a desk-based review of current trend forecasting practices. Five topics emerged from the examination of the literature of natural colourants: natural colourant sources; colouration technology; the application of natural colourants; culture and tradition; and industrialising natural colourants. Meanwhile, four areas arose from the literature of trend forecasting: technology, process, business and society. The in-depth analysis of natural colourant literature focused on “industrialising natural colourants” papers and discovered four key themes: industry scalability; consumer behaviour; economic value; and marketing and promotion. Comparison across these reviews identified opportunities for incorporating natural colourants through technology, marketing and education, supported by trend forecasting practices. Further research and significant adjustments in the industry are crucial, either to facilitate the integration of natural colourants into existing systems or to determine whether parallel standards and tools need to be developed.

The attraction of adopting natural and bio-based colourants in applications has grown, but their use suffers from a lack of certification bodies, standards and reference data. In the BioColour project, we are developing an open database and tools for the characterisation, authentication and quality analysis of biocolourant sources, biocolourants and coloured products. The database is multidisciplinary and currently combines taxonomy, botany and chemistry to form chemo-taxonomic authenticity fingerprints of biocolourant compounds. The database collates numerical structured data from targeted analyses, such as high-performance liquid chromatography-diode array detector-tandem mass spectrometry from published peer-reviewed articles and books. The target audience, in addition to researchers, and expected use-cases of the database, includes biocolourant refining, companies using biocolourants, dye conservators and archaeologists. For craft enthusiasts and hobbyists, the database also records material and colour information, consisting of both CIELab colour coordinates as well as spectral reflectance, of textile samples dyed with various biocolourants. We have implemented the database as an online service with a Django web framework and PostgreSQL relational database management system. This article discusses the key features of the current prototype database system from the user's perspective, demonstrating that the three main sections of the database are divided it into taxonomy fact sheets, chemical fact sheets and a colour palette. We published the database as an open publicly available online service on 16 December 2024.