Colour management in circular economy: decolourization of cotton waste

Abstract

Purpose -While aiming to create methods for fibre recycling, the question of colours in waste textiles is also in focus; whether the colour should be kept or should be removed while recycling textile fibre. More knowledge is needed for colour management in a circular economy approach.Design/methodology/approach -The research included the use of different dye types in a cotton dyeing process, the process for decolourizing and the results. Two reactive dyes, two direct dyes and one vat dye were used in the study. Four chemical treatment sequences were used to evaluate colour removal from the dyed cotton fabrics, namely, HCE-A, HCE-P-A, HCE-Z-P-A and HCE-Y-A.Findings -The objective was to evaluate how different chemical refining sequences remove colour from direct, reactive and vat dyed cotton fabrics, and how they influence the specific cellulose properties. Dyeing methods and the used refining sequences influence the degree of colour removal. The highest achieved final brightness of refined cotton materials were between 71 and 91 per cent ISO brightness, depending on the dyeing method used.Research limitations/implications -Only cotton fibre and three different colour types were tested. © Marjo Määttänen, Sari Asikainen, Taina Kamppuri, Elina Ilen, Kirsi Niinimäki, Marjaana Tanttu and Ali Harlin. Published by Emerald Group Publishing Limited. This article is published under the Creative Commons Attribution (CC BY 4.0) licence. Anyone may reproduce, distribute, translate and create derivative works of this article (for both commercial and non-commercial purposes), subject to full attribution to the original publication and authors. The full terms of this licence may be seen at Practical implications -With cotton waste, it appears to be easier to remove the colour than to retain it, especially if the textile contains polyester residues, which are desired to be removed in the textile refining stage.Originality/value -Colour management in the CE context is an important new track to study in the context of the increasing amount of textile waste used as a raw material.

How fashion can achieve sustainable development through a circular economy and stakeholder engagement: A systematic literature review

“…• Closing resource loops: this cluster includes CF practices implemented with an aim to keep materials in the economy, Closed-loop recycling, a process where unwanted resources and products are collected, recycled, and then used again to make the same product it came from, and thus to create a circular flow of resources • Recycling for manufacturing a same product type (e.g., recycling polyester fabrics to polyester yarn for the same fashion item production) 42 (44.7%) Al Faruque et al, 2019;Bloomfield & Borstrock, 2018;Bocken et al, 2017;Bukhari et al, 2018;Cattermole, 2018;Corvellec & Stål, 2019;Daddi et al, 2019;do Amaral et al, 2018;Earley, 2017;Earley, 2019;Fischer & Pascucci, 2017;Franco, 2017;Goldsworthy & Ellams, 2019;Haslinger et al, 2019;Holtström et al, 2019;Hu et al, 2018;Hussain, 2018;Hvass & Pedersen, 2019;Karell & Niinimäki, 2019;Koszewska, 2018;Leal Filho et al, 2019;Määttänen et al, 2019;…”

“…Enablers that can support fashion stakeholders to further promote CF Chadegani et al, 2013;Bocken et al, 2017;do Amaral et al, 2018;Earley, 2017;Earley, 2019;Franco, 2017;Goldsworthy & Ellams, 2019;Hall & Velez-Colby, 2018;Holtström et al, 2019;Hvass & Pedersen, 2019;Kjaer et al, 2019;Leal Filho et al, 2019;Määttänen et al, 2019;Norris, 2019a;Pal et al, 2019;Pedersen et al, 2019;Raebild & Bang, 2017;Sandvik & Stubbs, 2019;Smith et al, 2017;Stål & Corvellec, 2018;Valentine et al, 2017;Vehmas et al, 2018; Knowledge support…”

“…• Increase availability of facilities that collect unwanted clothing 21 (21.2%) Cattermole, 2018;Earley, 2017;Fischer & Pascucci, 2017;Hall & Velez-Colby, 2018;Han et al, 2017;Holtström et al, 2019;Hussain, 2018;Karell & Niinimäki, 2019;Leal Filho et al, 2019;Määttänen et al, 2019;Norris, 2019a;Norris, 2019b;Raebild & Bang, 2017;Sandvik & Stubbs, 2019;Shaw & Williams, 2018;Smith et al, 2017;Stål & Corvellec, 2018;Todeschini et al, 2017;Tunn et al, 2019;Valentine et al, 2017;Weber, 2019 Economic support Bukhari et al, 2018;Camacho-Otero et al, 2019;Franco, 2017;…”

Cellulose Fibers for High-Performance Textiles Functionalized with Incorporated Gold and Silver Nanoparticles

“…vinylsulfone groups in Remazol dyes) (Mahapatra 2016). Overall, reactive dyes can withstand color removal treatments better than direct dyes (Määttänen et al 2019), and colorants with anthraquinone units in particular were shown to have a high tolerance towards commercial laundering and oxidative bleaches (Bigambo et al 2018). To a certain degree, the strong covalent bonding of reactive dyes also tends to cross-link the cellulose structure, which can affect the final solubility of colored cellulose waste in ionic liquids or NMMO (Chattopadhyay 2011).…”

Pre-treatments of pre-consumer cotton-based textile waste for production of textile fibres in the cold NaOH(aq) and cellulose carbamate processes

“…The inhomogeneous constitution of cotton-rich waste material demands both its purification and tuning of the properties for achieving dissolution. Target of the pre-treatments is to remove non-cellulosic substances such as metals, ash, dyes, and residues of textile finishing chemicals, and to adjust the degree of polymerisation (DP) of the cellulose chains (Määttänen et al 2019). Thus, the quality of pretreated cotton-rich material meets the properties of commercial dissolving pulps.…”