Digital Textile Printing Offers Speed Alongside Sustainability

Machinery and Technology

Digital Textile Printing Offers Speed Alongside Sustainability

Digital textile printing has now been around for more than two decades and is seen as the future of print. Extensive research and development over the years has transformed the technology from being a product sampling solution, to a viable alternative to textile screen printing.

Digital print does still cost more than conventional rotary print, metre for metre, and yet, as a sector, it's set for massive growth, predicted at 18% in the next three years globally. This growth in textile sector is driven by the need to be sustainable, quick, flexible, and adaptability to new markets and applications.

The eco-conscious consumer

Sustainability is driving the agenda, and rightly so. Not so long ago just being organic was considered 'good enough', but today's consumer has an eco-conscience and the market must supply the products that they want to purchase.

The fashion industry is the second-biggest consumer of water, producing 20% of wastewater globally, while also generating more greenhouse gas emissions and using more energy than all international flights and maritime shipping combined. Traditional processes of dyeing and printing textiles put huge strains upon local eco-systems worldwide and the raw material resources of the countries that they operate in.

Digital textile printing has an extraordinarily low consumption of electricity. It is typically 3.5% of the screen printing energy requirement, however it is in its water usage that the difference is really paramount. Taking printed cotton as an example, each metre printed by conventional reactive printing uses between 50 and 60 litres of water per metre produced, in order to generate the colour depth and fastness required. This water is then discharged as effluent into the local water system where the chemicals and dyes pollute the local environment, unless they are re-processed through expensive effluent treatment plants.

By contrast, digitally printed cotton virtually eliminates the consumption of water and the discharge of noxious effluents. Using low volumes of liquid dispersions of pigment colours, digital print achieves similar physical results to traditional technologies without the huge environmental impact of rotary or flatbed printing. This is because the ink used in digital textile printing is typically 10% of the volume used when compared to screen printing. Digital printing using pigments also removes the need for water and energy greed post processing as well, since colour fastness is achieved by heat fixation alone as opposed to lengthy steam fixation and washing off procedures.

The mass market

However, as the market gears up towards the eventual digital switchover there are issues with the sustainable supply chain of the raw components. Stella McCartney, a lifetime advocate for sustainable manufacture, recently commented at the Copenhagen Fashion Summit on the poor availability of sustainable fabrics and components for those manufacturers that want to be greener. There are huge gaps in the supply of core products with a green eco passport. And, what's more, they are often an expensive option. Currently digital print is measured at between 5-7% of the global textile print marketplace; we are only at the beginning of this journey.

At present, sustainable products are not available to the mass market at an affordable price, and remain a considered purchase with a premium price tag. The lack of readily available, affordable consumables also applies to the digital print industry. Many ink suppliers offer, or are hurrying to develop, eco-friendly inks. But what exactly does eco-friendly mean? It's not good enough to loosely use a word to define and reassure the consumer as to the precise composition of the raw components in the prints that they procure. Consumers want detailed information of the chemicals that contact their skin. To meet the growing needs of our future consumers and the preservation of our planet, the print marketplace desperately needs standardisation and clear certification.

It's equally difficult to ascertain the chemical composition of printed cotton and polyester base fabrics as a printer (analogue or digital). In order to print digitally for cotton, as an example, the fabric also has to be pre-treated with a chemical mix to fix the printed colour to the surface of the cloth. The base cloth may already contain numerous nasty chemicals added during regular textile processing. Buying consumables from a certified source is critical. The certification of the final product will vary dependent on the ink, coating composition and coating method, alongside the base fabric source. Only when the entire supply chain is certified can we pass on a truly sustainable product.

A clear future

The end user demands clarity, and it will soon be a requirement of all print manufacturers, large and small, to list the certifications that apply to their products. Currently, these critical details are neither regulated nor compulsory for the sale of many products, and the boundaries remain blurred for required end use.

However, there is light at the end of this complex tunnel and various essential certification for sustainability and ethical supply are now in the public domain - GOTS, Sedex, Reach, UL208, Bluesign, Oeko-Tex, for example - some of which have existed for many years within our industry, and are becoming an increasingly popular and important requirement. Both printers and print buyers now require certification to offer clients a responsible product with a sustainable integrity.