Digitally printed fabric with disperse dye inks from Kothari Info Tech Ltd
Tansy Fall, Editor at World Textile Information Network (a great resource for news and analysis in the textile and nonwovens industries), shares her first exclusive piece with WhichPLM. She discusses digitalisation, paying particular attention to printing, fabrics and inks. Tansy studied at the University of Leeds, joining WTiN in 2014; she is responsible for the b2b Digital Textile magazine, as well as the newly launched IoTex magazine.
In many respects, the textile and fashion industries operate as two separate entities, with a wealth of apparel manufacturers bridging the gap, feeling cost pressures from below and margins being squeezed from above. This detachment stems from the globalisation trend of the ‘70s, which led to mass manufacturing in Asia, with vast amounts of infrastructure being established in China, and a dearth of skills in the West. It has enabled the “fast fashion” idiom to emerge, somewhat falsely, as fashion houses have gradually broken away from their fixed seasons to offer the consumer new styles more frequently. I say falsely, as the lead times for these “fast fashion” items are often extensive, designs are still created way in advance of their reaching the market, and garments are produced in long runs.
However, “fast fashion” is set to take on a new and truer meaning with the advent of the fourth industrial revolution, which sees an embrace of digitalisation enabling, or forcing (depending on your perspective), the industry to streamline and connect end-to-end. From fibre to garment, the value chain is contracting, not in terms of market size or business numbers but rather in terms of business collaboration at disparate ends of the industry. For example, we have seen Lycra fibre manufacturer Invista create the LYCRA F!T FINDER app, providing 3D body scanning technology to hosiery retailers and their customers, and many fashion brands are focusing on sourcing more sustainably, looking at eco-friendly dyes and fibres.
Software is playing a major role in the industry’s transformation, with ERP and PLM systems becoming more prominent – though not necessarily connected themselves – and 3D prototyping, the creation of “digital twins”, and data analytics encouraging new business models and linking processes. That said, without hardware that is able to connect to this software, the system somewhat falls apart.
The good news is that true automation of manufacturing processes is just around the corner, with strides being made throughout the textile supply chain, in hardware as well as software, for spinning, weaving and knitting, finishing, and garment pattern cutting and construction, among other areas. One sector that has been taking particularly large strides towards complete digitalisation is the printing sector.
Though analogue printing still makes up around 95% of all fabric printed globally, with over 31billion sqm being printed in total, the digital textile printing market is growing at a phenomenal rate with a CAGR of up to 20%. More and more, we are seeing this technology being installed in the US and Europe, and the domestic Asian markets are also becoming increasingly demanding of Chinese print houses that have established huge export businesses. Turkey, the Middle East and Eastern European countries are also investing heavily as a near-shore alternative for brands in Europe.
Indeed, this near-shoring trend, and the on-shoring trend that has emerged, is set to change the face of the textile and fashion industry – moving from a global manufacturing economy to a localised manufacturing economy – and this is largely being enabled by digital textile printing advancements.
A digitally printed bridesmaid dress. Picture by Stephanie Veldman Photography
The ability for a design house to invest in digital printing technology, or work with a local partner, to bring their designs to life in a timely fashion has seen the establishment of vast numbers of small print bureaux. Many of these are also offering cut and sew capabilities, selling bespoke products into their local markets. This in itself is not a challenge to mass manufacturing – despite being a great opportunity for SMEs – but if we extrapolate this small business model and look at it from a retail brand’s perspective, the potential of the localised micro-factory to change the landscape of fashion and textiles is huge.
Let’s take a fictitious brand: Brand X. Brand X currently mass manufacturers the components for it’s clothing in various locations across Asia, and then exports globally. The reason for this is that the cost of textile manufacturing in Asia is low compared to other regions, as is the cost of garment construction due to labour costs. However, more and more there are other factors to consider. Firstly, sustainability. This has been a buzzword in all industries over the last decade but it is increasingly being catalysed by global political initiatives and, crucially, sanctions. Pollution of water supplies and carbon emissions are under scrutiny, with China having shut down an entire manufacturing province for over a week ahead of the G20 summit last September, in order to reduce the amount of apparent pollution. Labour is also a prominent factor driving change. The 2013 Rana Plaza disaster in Bangladesh brought working conditions to the forefront and this combined with rising wages in the BRIC countries – China in particular – means that cheap labour is quickly becoming no longer an option.
Based on this, Brand X decides to seek out a new business model. The management at Brand X has noticed a number of bespoke print bureaux with garment construction capabilities, marketing unique designs, starting up in many of its target markets. It also considers its e-commerce business that it would like to expand due to consumer shopping patterns. In order to do this, it would like to offer the customer a more personalised experience and also reduce its time to market. Tied in to this, Brand X is also looking to reduce warehousing costs and inventory, as its products are shipped globally. Brand X has also begun to analyse data collected from consumer feedback about different sizing needs in various regions, and different preferences in style across those regions as well. These are the trends we see emerging in the fashion industry, and all of this undermines the mass manufacturing mentality.
What this may lead to is the dawn of the local micro-factory – though micro, in the end, may not be the most appropriate term for it; rather localised, automated manufacturing, customised to the local market. Digital textile printing is a key element in this chain, for taking greige to garment, with many print technology companies now offering inline solutions, and partnering with cutting businesses to bring this technology inline as well.
Is the technology ready?
Digital textile printing technology has evolved very quickly, from the printers to the inks, the substrates and their pretreatments, and the software.
If we begin by looking at printers, digital technology is now available in a variety of sizes and capabilities. Entry-level machines typically run at around 30sqm/hr and have been adopted by many fashion brands as a means of creating print samples in-house, particularly in fashion capitals like New York. These printers range from around US $15,000 to US $30,000, with popular machinery brands Epson and Mimaki taking prominence in this sector.
Moving on to the mid-range printers, which print at around 100sqm/hr, as an average, these are the kind of production machines that would be found in a SME print bureau, which may have multiple printers, running different ink types. These printers usually retail for around US $50,000 to US $100,000, though second hand purchases are frequent. Brands such as MS Printing Solutions, D.Gen and DGI stand out in this area.
High speed machinery is a huge area of growth in the industry. There are now a number of single pass digital textile printers, with fixed print heads, that are capable of rivalling the productivity of analogue printers, running at speeds of up to 4800linear metres/hr. Of course, the quality of the print also has to be taken into account here, and it’s likely that this number is somewhat unrealistic as a production speed. However, progress is constantly being made in this area, and there are now eight varieties of single pass printer on the market. Top manufacturers in this area include MS Printing Solutions, SPGPrints, Konica Minolta and Atexco.
In addition to these printers, the speed and resolution produced by high speed scanning machines (where the printheads aren’t fixed but run back and forth over the substrate) is also improving. EFI Reggiani’s ReNOIR TOP is claimed to print at 1200sqm/hr, for example, and other technology isn’t far behind. Both the high-speed scanning printers and the single pass printers are priced upwards of US $250,000.
Another factor that needs to be considered here is the time that is saved due to the lack of screens. Where shorter runs are being demanded by consumers looking for personalised products, this enables efficient switching between designs and should save on consumables as there are no screens to wash. Feedback from users also suggests that the resolution technology has improved to the point where companies are able to print complex designs at high resolutions without any difficulty.
Picture by Printtech
Inks used in digital textile printing are based on either water-soluble dyes or finely milled pigments. The dyes come from the same classes as those used in dyeing solid colours or in traditional screenprinting, but their formulation in mixtures with other ingredients must be sufficiently precise to match the specific characteristics of the inkjet print head in which they are to be used. For that reason, digital textile ink manufacturers will usually offer several variants of the same product, each carefully formulated for the print heads of a specific supplier (Epson, Kyocera and Ricoh etc.), but there might be some machines, with different heads, in which their inks will not work reliably.
Dye sublimation inks make up the single largest digital textile ink category and are used only on polyester, applied under heat and pressure, turning the dye from a solid to a gas, becoming fixed when it cools and reverts to a solid. The most popular method is to print onto transfer paper and use a calender with heated rollers to transfer the dye to the fabric. The advantage of this method is that it does not require the fabric to be chemically pretreated and has no wash-off phase either, so is very efficient.
Disperse dye inks are also used on polyester and are closely related to dye-sub inks, in that both consist of fine dispersions or colorant in suspension. However, no “sublimation” takes place in their application – the dye molecules simply migrate into the surface of the fibre under the special conditions created during a direct printing and heat fixation process. Fabric must be pretreated beforehand and, for clothing applications, washed afterwards.
For natural fibres, reactive dye inks are used and this is another important category for fashion. The dye molecules react with the fibre to create a permanent chemical bond. Reactive dyes give bright, saturated colours, but do not always have the highest light fastness. Pretreatment, steaming and washing are all required. Their brilliance and ability to achieve deep shades – especially intense blacks – means reactive dyes are also increasingly used on protein-based natural fibres such as wool and silk.
Acid dye inks are traditionally used on wool and silk, but their role is being eroded by the capabilities of reactive dyes, whose process requirements are similar. However, acid-dye inks are also the main category used on nylon, and remain important in product areas such as swimwear.
Finally, the ink that is currently the focus of development efforts is pigment. Unlike dyes, pigments do not penetrate the fibre but are held on its surface by a binder, and their fastness to washing and rubbing etc. depends on the effectiveness of the binder. In conventional printing, they are the most important type of ink used in home textiles, and are also the basis of most digital direct-to-garment printing. Pigments have the potential to offer the perfect “all round” solution, in that they can be used on any fabric type, including blends, with no finishing process other than drying and baking. They also have good light fastness. However, in industrial-scale digital fabric printing, they have been problematic due to a restricted colour gamut and the risk of clogging in the print heads. A lot of R&D has been devoted to these questions and, with new inks and new recirculating print head types, several suppliers are now offering high-production pigment printing solutions.
The real opportunity for digital textile printing is likely to lie in high speed scanning machines or single pass machines that can print with pigments. If this technology was optimised, it would be a serious challenge to the screenprinting industry, both in terms of speed and final quality of the print.
Pretreatment is another crucial part of this. Whilst pigment inks don’t necessitate a pretreatment, feedback from printers in the industry suggests that the results achieved when a pretreatment is used are far superior to those without. Pretreatment can be brought inline, which maintains the digital automation aspect of the printing process, but fabrics already pretreated are also available for purchase from a number of global suppliers, the most prominent of which is UK-based Premier Textiles.
New York based Dyenamix combines digital textile printing techniques with other innovative textile design processes to create unique effects for the catwalk
With all this technology available, what business models are emerging?
When it comes to changing business models, there are many in the industry that are content with only analogue printing. Currently, this makes a lot of sense as analogue still makes up 95% of all printed fabric. And, the decision not to invest in digital is largely down to price – of the technology and the consumables – and the capabilities that are on offer, both in terms of final product quality and productivity, despite leaps being taken in this area. However, many of these businesses are eyeing up potential investments as the digital textile printing industry develops, and it’s likely that many will choose to invest in digital in the future.
In the meantime, there are a plethora of businesses that have invested only in digital printing. Though, as I have said previously, many of these businesses are SMEs, there are some larger companies emerging that have invested in single-pass technology and high-speed scanning machines, and these businesses are seeing a return on investment and interest globally. However, there are pitfalls in this model, as there are gaps in the capability of digital technology. Metallics, for example, cannot be printed using a digital method, and neon colours are also hard to achieve the same brilliance as with analogue printing. Pigments too, as mentioned before, are an area of contention.
Larger businesses that are seeing the most growth are those invested in both analogue and digital technology. This enables flexibility when it comes to design, print-run lengths and cost. And this can all be decided on, or at least discussed with the individual customer, bringing the personalisation trend into the B2B space.
Advances in software are also enabling some unusual opportunities to arise alongside digital print technology, including printing on shoes, on umbrellas, and on tents, among other unique applications.
Digital textile printing is giving rise to new business models and is connecting the manufacturer with the retailer – the beginning of digitalisation.