Bio-based pigment inks for inkjet printing applications

 
Currently, we are facing a transition from traditional textile printing processes to digital ones. Due to sustainable concerns, the market demand is moving towards digital printing with pigment inks, as this process is more sustainable than the ones with dye inks, such as reactive or acid inks, which require a pre-treatment with urea and post-steaming and washing treatments, with consequently higher environmental impacts. Pigment inks are versatile as they can be used with almost any textile fibre. The majority of the pigments and dyes used in textile inkjet printing are still fossil-based. The bio-based pigments and dyes on the market have limited availability and colour palette, are less stable than synthetic ones, and often display a poor resistance towards UV. They are typically obtained from plant and food extracts, limiting their shelf life, and some even require dedicated cultures to provide the plant raw materials for the extracts. Bacterial fermentation to obtain colouring agents is still limited as to the properties of the obtained dyes (e.g., low colour fastness to light), and the quantities produced, but some promising alternatives are the one from PILI, which is producing several nature-based pigments and dyes by (bacterial) fermentation followed by chemical routes, and those where the colour producing bacteria is cultivated directly on the textile, dyeing it simultaneously and leaving unique growth patterns on the fabric. However, bio-based pigments have been applied mainly by conventional padding and exhaustion dyeing processes, leaving a need to introduce them into digital textile printing. To achieve this, the EU-funded project Waste2BioComp (GA 101058654, 2022-2025) aims to demonstrate relevant scale production of, among others, bio-based inkjet printing pigment inks, to be developed by partner CITEVE, as alternatives to traditional ones with a high environmental footprint, using the bio-based pigments under development by partner PILI. These pigments are being used on the development of water-based inks for inkjet printing for fashion applications. Furthermore, other common components of the inks are also being replaced by bio-based alternatives, and their behaviour is being studied. The replacement of currently used pigments (from fossil-based sources) by bio-based alternatives and the implementation of sustainable printing technologies, such as inkjet printing, will further contribute for the EU goal to achieve climate neutrality by 2050. The EU-funded project Waste2BioComp, coordinated by CITEVE, developed bio-based inks using PILI's nature-based pigments produced by combined biotechnology and chemical routes. These inks replace high-footprint fossil-based ones and support the EU's 2050 climate neutrality goal, which have been assessed by LCA study (Life Cycle Assessment). The main applications of these new biobased inkjet inks include textiles, leather, and paper. This work was carried out under the Waste2BioComp project - Converting organic waste into sustainable bio-based components, GA 101058654, funded under the topic HORIZON-CL4-2021-TWIN-TRANSITION-01-05 of the Horizon Europe 2021 - 2027 programme.