Tech advances in screen printing, sublimation

Dye sublimation printing continues to evolve and enhance its performances, providing users with high quality printed products and DTG printing keeps higher speed capability enabled through new generation printheads, highlights an exclusive ITJ Report.

Despite the headway digital printing has been making in the last few years, screen printing with a share of over 90 per cent (rotary screen and flat screen printing) in textile printing is here to stay, thanks to their flexibility, cost-effectiveness and also some technological leaps. Dye sublimation transfer printing has a three per cent share, but its textile applications have been widening to cover sports merchandising, fashion apparel, soft signs (polyester banners and flags), home furnishing interior décor, promotional items and personalised gifts.

Direct-to-garment (DTG) screen printing has made rapid strides, particularly in India due to t-shirts boom for sportswear and casualwear from textile hubs like Tirupur, Tamil Nadu. The Vasai-based Grafica Textronica has launched many versions of DTG screen printing machines, of which GraficaTex, an automatic version, is doing well not only in the domestic market but also in export markets like Turkey and Egypt. Bhargav Mistry, Managing Director of Grafica Flextronica, is passionate about printing and had launched a decade ago DMI, an exclusive institute at Vasai in Palghar District of Maharashtra, for training and providing skilled workers in printing. It is imperative to realise that printing has been one of the neglected areas in textile industry in India so far and in the last one decade has been attracting keener attention of the industry with accelerating technologies and applications.

One more evolution that is happening in printing world is in the printing chemicals and auxiliaries including the inks. The traditional printing needs colour management, sample printing, actual printing, steaming, washing and finishing. To keep the traditional printing alive and kicking, the industry has to invent to shorten processes and take steps towards sustainability and environmental protection.

“One big thing happening is that everything in printing is moving towards environmental protection and waste reduction. A lot depends on what you use to protect environment and there is a price for it. Besides, the Government regulations change from country to country. But the basic is to balance inputs and promote sustainability. Even in the US, it varies from state to state. Or look at digital printing, and it is moving towards more water-based colours. But here is also there are resins, which have to be filtered out,” said Charlie Taublieb of the Colorado-based Taublieb Consulting.

Talking of sublimation transfer printing, he said: “Sublimation printing is making strides everywhere all over the world. It is easier to deal with in DTG printing. But the biggest downside is that the material has to be 100 per cent polyester. Or at least 50 per cent polyester.”

Every type of printing—be it screen, flatbed, rotary, dye sublimation transfer, DTG—has its own following and advantages. Digitalisation, though at present having cost implications, is encroaching the other territories. Dye sublimation roll-to-roll inkjet printing technology or transfer printing was the first to be adopted by the textile printing industry in order to print onto fabrics. The dye sublimation printing process consists of two steps: the designs are printed onto paper first and then they are transferred onto the fabric through a heat press process which is combination of heat, time and pressure. Although dye sublimation printing is not a new technology, it continues to evolve and enhance its performances, providing users with high-quality printed products. Dye sublimation inks work particularly well on polyester, therefore dye sublimation printing in the textile industry is mainly used to produce soft signage applications and sportswear, namely sportwear apparel whose function has extended beyond sporting activities into daily wear clothing.

Roland DG, a multinational represented by the Apsom Infotex which has a national distribution infrastructure, with offices across major cities in India, Sri Lanka, Bangladesh and Nepal, is a leading player in dye sublimation transfer printing. Its Texart XT-640 and Texart RT-640 are one of the best dye-sublimation transfer printers crafted totally to suit the textile printing industry.

In the early 2000s, DTG printing on t-shirts had emerged using modified desktop inkjet printers, pigment inks and fabric pre-treatment. Today, this market has evolved to drive over 200 million garments annually as the initial modified systems developed into a multi-vendor industry encompassing dedicated DTG machines from desktop devices printing around 20 t-shirts per hour up to production systems that in some cases can print more than 400 t-shirts per hour.

DTG printing continues to see higher speed capability enabled through new generation printheads and using larger, as well as multiple platens that can begin to challenge screen processes or can feed a growing on demand printing sector in geographies previously reliant predominantly on imports.

Advances in digital prepress and digital add-on solutions for screen carousels enable the screen garment printing industry to gradually integrate digital technology where replacement is not yet a reality. However, advances in inkjet flatbed printing with bidirectional printheads is now starting to enable garment printing on all types of fabrics and all types of sizes. Continued developments in the automation of pre and post processes including cut and sew will drive this sector further into the traditional market for both t-shirt and apparel printing.

The textile printing industry is one of the biggest and most dynamic in the world. It is a lively, responsive sector that in 2014 generated a volume of around 31 billion sq m of printed textiles on a global level (Source: Provost fnkJet Consulting). The geographic split clearly shows China, which produced on its own 29.3 per cent of the total, at the top followed by EMEA (23.1 per cent) and India (17.6 per cent). The remaining amount is divided between the rest of Asia (17.4 per cent) and the American continent (12.6 per cent). The sector will continue to grow over the coming years too: global production will go over 33 billion sq m in 2017, marking an annual increase of 2.5 per cent.

An interesting perspective on the market is provided by the analysis of the share out of technology in textile printing. Rotary screen printing is still the most used technology with a 65 per cent share on a global scale, followed at some distance by automatic flat screen printing (25 per cent), while hand screen printing and dye sublimation transfer printing grab a 3 per cent share. The value of digital printing – the latest technology to have made an appearance on the textile industry production stage – is around 2-3 per cent, and it is this technology’s potential and development prospects that are drawing the attention of the entire sector.

The expansion of the printed t-shirt sector is directly tied to the evolution of DTG technology printing straight onto the garment. This is a phenomenon that exploded 15 years ago and has grown rapidly because of its ability to satisfy the demand from the mass market for original, personalised items. Even if the market has reached maturity, the development of increasingly high-performance print solutions in this field and the boom in web-to-print services have continued to boost the business. The most recent technological evolutions concern the widening of the range of printable fibres and textiles with DTG solutions and the automation of the pre- and post-printing services solutions. Strengthened by these implementations, the sector should continue to grow over the coming years, though at a slower pace than in the past, potentially taking some slices of the market away from traditional printing.