Digital textile printing using water-based inks is often touted as a solution too many industrial problems associated with the textile industry. However, risks associated with the use of hazardous materials in complex formulations do remain.
In addition to chemical sustainability, a recent “open letter” from a group of textile chemical companies has highlighted the issue of compliance as being a threat to the sustainability of business models in the industry. In this article I will look at both of these areas and the key issues facing businesses involved in the development and use of inks for digital textile printing.
The use of inks and digital printing to produce patterns and colours on fabrics for textile, home and automotive applications is inherently more efficient than traditional analogue dyeing processes. Inks are only applied where they are required and the need to pre- and post-treat fabric prior to colouration is greatly reduced. The vast majority of inks for digital textile printing are water-based and are applied either directly to the fabric (reactive, disperse and pigment inks) or to paper and then transferred to the fabric (sublimation inks). This means that, unlike traditional dyeing, there is almost no waste and, unlike other types of printing, no hazardous solvents.
A key driver in the adoption of inks for digital textile printing has been advances in printer and print head technologies. This has improved the productivity of machines and made printing an attractive option, particularly for on-demand, advertising and fast-fashion applications. However, these advances require ink formulations to be extremely stable. Thousands of tiny nozzles in expensive print heads must fire rapidly and repeatedly over many months and cannot be damaged or clogged by inks. The leading inks in use today therefore include surfactants, stabilisers and solubilising agents to maintain consistency. While reputable companies ensure that these additives are not harmful, there is a temptation to use well-known chemicals such as APEOs, NPEOS, formaldehyde and chlorophenols. Many of these harmful additives have been phased out of analogue textile dyes through efforts of sustainability-focused manufacturers and industry-based regulatory frameworks. However, to date, these frameworks have not focused their attention on inks. Also, the relatively low capital costs of ink formulation have led to the emergence of many low-cost ink suppliers who only do formulation, not synthesis of the chemicals. In combination, this means that the risk of hazardous chemicals entering textile supply chains through inks has not been completely eliminated. A sustainable ink, from a chemical and environmental perspective, is therefore still a commercial goal rather than an industrial reality.
The commercial sustainability of inks for digital textile printing is also a key challenge for the industry. Relentless price pressure, such as that seen in the ceramics industry, if left un-checked, will inevitably lead to reductions in quality and safety. Should this occur, the entire value proposition of inks for digital textile printing could be undermined? Regulation by the broad recognition of the aforementioned industry frameworks is one way to promote value-based pricing and to prevent a “race to the bottom” in terms of both quality and price.
As a leading chemical manufacturer with almost 50 years’ experience in the textile industry, Kyung-In Synthetic Corporation (KISCO), has long recognised the benefits of these regulatory frameworks and has actively supported, implemented and complied with global standards as put forward through initiatives such as bluesign, ZDHC, GOTS and the Sustainable Apparel Coalition. However, in the recently, a collection of other chemical companies who operate in the textile industry have flagged some concerns about these frameworks.
In an “open letter” to the Stichting ZDHC Foundation, the group of chemical companies has highlighted the issues involved in complying with an increasing number of regulatory frameworks. They have called for unified standards, highlighting the strengths of the bluesign and ZDHC initiatives. They have also highlighted the proliferation of brand-based standards and pointed out that duplication of compliance initiatives complicates efforts and adds costs. At KISCO, while we proactively comply with relevant regulations, we do regularly hear from our partners that retailers and brands are insisting on an ever-increasing number of certifications. Commercially, this is not sustainable and the whole industry needs to recognise that safety can best be achieved through supply chain consensus rather than differentiated branding of company-based frameworks.
In summary, inks for digital textile printing do represent an opportunity for the industry to dramatically reduce waste and improve our chemical and environmental sustainability. However, financial pressures in the form of demands for low pricing and the imposition of significant compliance costs risks creating a situation where corners are cut. The industry has made significant progress in improving the quality and sustainability of dyes. It is important that similar efforts are continued with respect to inks.