Textile printing is said to be one of the fastest growing areas in wide-format, but you do have to tailor the applications around the available materials?
There’s no doubt that digitally printed textiles is a huge and growing business. But this is partly because it is made up of several very distinct markets. The biggest of these is the garment sector, which itself can cover a huge range from high street fashion to the occasional promotional T-shirt. This includes printing to various materials from cotton to silk, which require specialist printers with inks suitable to these materials, and plenty of washing before the garment is ready to wear.
In contrast, the wide-format graphics market is all about printing to polyester-based materials. These days there’s a host of different substrates available that include a blend or coating of polyester, and in turn we’re witnessing a real rise in soft signage. Indeed it was very noticeable at events such as Sign and Digital and Fespa 2013 that many of the exhibition graphics were made out of large textile panels. Such panels are very lightweight which makes it easier, and therefore cheaper, to install them, especially those suspended above a stand. They are also easier to transport and to store and, being washable, easier to keep clean for re-use. In addition, textiles are easily recyclable, making them a much greener alternative than PVC.
Some wide-format print companies have also had success in printing for the interiors market, in some cases for bespoke home furnishings and more commonly for office interiors, where a fabric can give a softer, more welcoming feel to a wall covering.
So for those of you thinking of getting involved in textile printing here’s an overview of the technological developments worth noting.
Transfer printing
The main method of textile printing is dye-sublimation, which usually involves printing the image first to transfer paper and then using a heat press to fuse the image to the final fabric. The heat press uses a combination of pressure and heat - typically around 180 to 210C. This process drives the ink colourants right into the fibres of the textile so that the material retains its own natural look and feel, and ensures that the graphic will last a reasonable length of time.
The classic approach to dye-sub is to use specialist aqueous inks, of which there are several third party offerings that aim to convert existing printers for textiles use. Sabur, for example, will convert Roland’s range of eco-solvent printers for dye-sub use without compromising the original warranty. However, Duncan Jefferies of Mimaki dealer Hybrid, says that many people are also using a standard eco-solvent ink, since the heat press helps evaporate the solvents.
Direct-to-textile
The alternative is to print direct to the textile, thus cutting out the transfer stage. Some printers will do this with dye-sub inks, while others use disperse dye inks. They’re both water-based inks but as a general rule the disperse dye ones have much better lightfastness and so are more suitable for outdoor use.
Aaron Burton, digital development director for Sabur Ink Systems, says disperse dye inks give a better show through, making them more suitable for flags and banners, though he adds that using a paper transfer print leads to higher depth of colour for the front of a graphic.
Another option is to print direct with latex inks. The inks tend to sit on the surface but the results are certainly adequate for flags and banners, thus obviating the need to invest in a specialist printer and finishing unit.
DRYING/Fixation
Some direct-to-textile printers do come with built-in drying or fixation, but in most cases you will need a separate unit. Leaving aside the more industrial solutions, most graphics users will have to choose between a flatbed and a calendar heat press.
Roland Biemans, marketing manager for Hollanders, says: “The calendar system came first because it’s easy to build and you can do transfer printing and use it as your heat press. You can even use it for some form of laminating because you press the material together and apply heat.”
But he warns that it takes time to heat up these presses in the morning and that their productivity can be limited by the need to maintain the temperature. He says that it can take up to 45 minutes to get a calendar up to the right temperature, adding: “You have to put a lot of energy in to meet the operating requirement that’s not going into production.”
Flatbed heat presses on the other hand tend to be cheaper and are usually aimed at lower production environments. However, Jefferies points out that some companies use a large heat press to fix a dye-sub image to a rigid board, which gives a lightweight graphic with a very high gloss finish.
Sabur sells the Klieverik range of calendar presses. The base model is the GTC 81, available as the 1850, with a 1.6cm width, or the 2300, with a 210cm width. It’s a solid machine with an oil-based contact temperature control and a built-in cooling down timer, which should increase production time. It can run at up to two meters per minute. It comes with winders for both fabric and transfer paper.
There’s a larger model, the 3400, with a 320cm width. This uses an electrical thermo-oil heated system to give a very uniform and accurate temperature control, which can be adjusted up to 220ºC. It can produce up to 140m2/hr and Sabur claim that it can handle the output of several printers.
Also available is a GTC Sport model, which is designed to align images from a roll of transfer paper with individual fabric pieces. There’s a table to help an operator line the different pieces up before they are fed into the rollers. Klieverik also produces a really heavy-duty model, the 3500, which can run at up to four meters per minute and produce around 340m2/hr. There are three different sizes from 200 cm to 350cm.
In addition Sabur sells the Sefa PST1510, a flatbed heat press. This uses a twin platen pneumatic design taking materials up to 100 x 150cm. The temperature is adjustable up to 270ºC, with a dwell time up to 570 seconds and pressure up to 160 Bar.
Kala has developed the DS67 Calendar. This roll-to-roll machine can also handle sheetfed applications. It can produce just over one meter per minute at a temperature up to 220ºC. It can cope with most fabrics including stretchy materials and is a good cost-effective solution for both transfer and direct printing.
RA Smart supplies the George Knight range including the Maxi Press, a wide-format flatbed heat press. This uses hydraulic springs so it’s easy to use. It has a heavy steel frame structure with a self-leveling heater block and adjustable platen height. It is available in two sizes: 80x 106cm and 110x 160cm.
Fespa 2013 launches
A number of new textile printers targeted at the graphics market were launched at the Fespa 2013 show this summer. Agfa, for example, has signaled its intention to enter the textiles market with its new Ardeco, although it wasn’t actually shown at Fespa. This is aimed at the high volume market and boasts a built-in calendaring unit. It’s a 3.2m wide machine with Dupont disperse inks, capable of producing up to 137m2/hr. It uses the Ricoh Gen4 printhead and there’s a choice of eight or 12 heads. Resolution is 600 x 600dpi. It has an ink-through feature that means that highly absorbent and open-weave fabrics such as meshes can be printed without suffering damage from ink splash back.
The Portuguese company POD launched two new models, including a 3.2m wide version of its Mtex 5032 dye-sub printer. This has a speed of 58m2/hr and can print at a maximum resolution of 1440dpi. It uses four Epson DX5 printheads and includes an integral infrared fixation unit.
POD also showed the Mtex Turbo Sub, a direct-to-fabric printer with integral infrared fixation unit. This runs at 110m2/hr with 1200dpi resolution. It uses six Ricoh Gen5 printheads and can print up to 1830mm wide.
Durst upgraded its existing textile offering with the launch of the Rhotex 322, a 3.2m wide printer capable of producing 140m2/hr at a resolution of 1200dpi, thanks to the use of Durst’s VarioDrop greyscaling technology. It’s designed for unattended printing round the clock and uses disperse dye inks, which are suitable for up to two years outdoor use.
Mimaki also has a new textile printer, the TS500, which has a maximum print width of 1890mm and a maximum throughput of 150m2/hr. It’s designed for high volume production, aimed mainly at the soft signage and interior decoration markets. It uses the Ricoh Gen5 printheads. The ink is supplied in a non-degassed form, with the printer degassing the ink once loaded which makes the ink cheaper than previous models.
Mimaki’s other main option is the JV530, which can print direct-to-textile, or via transfer paper. It incorporates a plate with a trough so that you can run materials such as flags, meshes and voiles through the trough ensuring that the ink penetrates right through the material.
Mutoh showed off its ValueJet 1638W, which won an award from the European Digital Press association as Best Wide Format Textile printer at Fespa 2013. This is a 165cm wide printer using a staggered dual head configuration with four colours across eight channels to reach speeds of up to 65m2/hr. It will take either dye sublimation or disperse dye inks to print to either transfer paper or direct to textile.
Epson launched two new dye-sub printers earlier this year, which we’ve covered in more detail in this month’s Machine Matters feature. The F6000 is a 44in-wide entry-level machine while the F7000 is a more heavy-duty beast with a 64in print width. Both can print up to 1440dpi resolution and use Epson’s water-based Ultrachrome DS inks. Epson is also developing a direct to textile printer that should be announced by the end of the year.
Third party inks
As we’ve already noted, there’s a healthy market in developing dye-sub inks for textile use and a number of new one were announced at Fespa 2013.
Sensient Imaging Technologies launched a new set of water-based inks called ElvaJet Alpha for printing directly to polyester fabrics. These inks boast very vibrant colours and can be fixed with dry heat, needing no further washing or other finishing step. They penetrate through the fabric, with a similar level of colour vibrancy on the reverse side. Sensient claims that they are more environmentally friendly than comparable inks, using around one litre of water per linear metre, while other inks require anything up to 100 litres of water. This also results in energy savings and reduced CO2 emissions.
J-Teck3 used Fespa 2013 to launch a new series of inks for sublimation and direct-to-fabric printing on polyester, called J-Cube, with an RF40 version for printers with Ricoh heads and a KF40 for printers with Kyocera heads. Both use CMYK colours.
Bordeaux showed off its water-based Eden SD inks, which are designed for direct-to-textile applications. These are high-density inks that use high performance dyes to prevent the dyes migrating and bleeding. This ink is compatible with all printers using the Epson DX4 and DX5 printheads.
In conclusion, there are a number of options open to wide-format print providers looking to enter the graphics textile market. There are several new high production printers but it’s also possible to convert older printers to test out the market or to try different applications. The most flexible option is dye-sub via transfer papers, which is suitable for the greatest range of materials including stretchable fabrics.