Traditionally this has been mainly done by screen printing but in recent years we have seen a number of direct-to-garment (DTG) printers developed. And, more recently, a new technique, direct-to-film (DTF) has appeared.
With DTG, the ink is jetted directly onto the garment. It works best with natural fibres, such as cotton, linen, bamboo or blends thereof. You will usually need to apply some kind of pre-treatment to hold the ink. With many of the smaller desktop machines this has to be sprayed on manually, while some machines will do this immediately prior to printing. The garment is stretched on a platen and the image printed directly onto it. Most vendors offer a range of platens for holding t-shirts, hats or other items. Afterwards, you just need to place the garment in a heat press for a few minutes to fully cure the ink.
In the last couple of years a new approach, printing direct to film, has arrived, driven largely by low-cost machines from China that have caught most of the established players on the hop. Alex Mighall, product marketing manager for RA Smart, notes: “Nobody was expecting it to boom as quickly as it has done. But I am sure that we will see more and more OEMs that we know coming out with their own machines because for sure it’s here to stay and we are only going to see it growing over the next couple of years.”
The main advantage of DTF is that it will work with a wide range of different materials, including polyester, cotton and nylon. In addition, it’s a relatively cheap process, with reasonable productivity since there’s no need to apply a primer.
The technique is split across two stages, starting with a roll-fed inkjet printer, typically around 600mm wide. The design is printed onto a transfer film using a water-based inkset formulated for this purpose.
From here, the film is fed from the printer into a machine variously referred to as a powder shaker, powder curing unit or an applicator. This device spreads a hotmelt adhesive powder onto the design and shakes it to ensure that you have the right amount of powder spread evenly across the design. The powder is heated to melt it onto the film, and then cured so that the film can be wound onto a roll. Some vendors include the powder shaker with the printer but many leave it to their local distributors to source a suitable unit and create a bundled offering.
After this you end up with a transfer print that can be applied straightaway or posted to a customer. The final stage is to place the blank fabric together with the transfer in a heat press. The plastic base can be peeled and is usually recyclable so there’s no sustainability issue.
The principal difference between the two approaches is that the DTG ink soaks into the fabric, while the DTF ink sits on top of the material. This means that the DTG garments have a much more natural feel to them, while the DTF ink can feel quite plasticky, particularly on large graphics. On the other hand, the DTF inks can deliver more vibrant colours. Also, there is a degree of stretchability in the DTF prints that makes them very well suited to sportswear.
Mighall points out that the film transfer process is more forgiving of seams and buttons. He says that it’s particularly suited to printing on hoodies and workwear, including hi-viz vests and sportswear.
However, Folker Stachetzki, marketing manager for Brother, argues that because of the superior hand feel of DTG prints, DTF should be seen not so much as a competitor technology to DTG but instead as a supplement. He says: “With little effort, you can produce a motif for a wide variety of textiles, for example, logos to apply to shirts, polo shirts, caps, polyester and so on. This is where DTG printing sometimes reaches its limits. DTF printing also scores well on solid prints, but loses out on photo-realistic, fine motifs and gradients.”
What’s available?
Mimaki introduced the TxF150-75 DTF printer earlier this year. It’s based on the existing 150 series wide-format printers and has a maximum printing width of 800mm, with five colours: CMYK plus white. Mimaki has also developed a new water-based PHT50 heat transfer pigment ink to go with this printer.
Inktec has developed a complete DTF solution, starting with a 600mm-wide printer. This can produce up to 15sqm/hr in its fastest six-pass mode. It uses Inktec’s pigment ink, with a CMYK plus white inkset. Inktec’s solution also includes a compact powder shaker that features an auto powder recycling system with a three-stage heating system.
RA Smart distributes a number of different types of printers, including the Polytech DTF range.
There’s a choice of two 600mm-wide machines. The basic model has two Epson printheads and takes a CMYK plus white inkset. The Pro version has four heads and a choice of two inksets, both of which have white plus either two sets of CMYK or CMYK plus orange, blue, red and green. The solution also includes an applicator to apply the powder and cure the image.
Azon Printer has seen a lot of interest in its Primo+ Neon X, a 600mm-wide printer that has 10 colour channels: CMYK plus two whites and a further four neon colours – magenta, yellow, red and green. Essentially it’s a more automated version of the existing Pronto+ Neon X, with automatic nozzle check and cleaning, plus some ink recirculation and agitation of the ink tanks to prevent sedimentation. Ricoh is also selling a rebadged version of this printer.
Axzyra, which mainly sells industrial inkjet printers, also sells two DTF machines. The DTF300, which has a 300mm print width, is a complete unit including the printer, powder application and drying for a more or less automatic solution. There’s a larger DTF600, with a 600mm width, which is made up of a separate printer and powder shaker. Both use two Epson i3200 printheads and print CMYK plus white.
Polyprint has developed the TexJet New Generation range of DTG printers offering different levels of productivity. These all use Epson i3200 printheads with resolution up to 720x4,800 dpi. The top of the range NG140 can produce up to 56 dark garments per hour, or 64 light garments. These printers can also print up to 45 DTF sheets per hour, using the same inks.
PolyPrint has also shown off a prototype of a new DTF machine, the FilmJet. This is an all in one automated unit that includes the printing and film processing. It uses the same print engine as the TexJet NG machines and takes rolls up to 600mm wide and 100m long.
Epson has recently introduced a new desktop DTG printer, the F2200, which replaces the older F2100. The main difference is that this gains the same printhead as fitted to Epson’s much larger F3000 DTG printer but where the F3000 has two heads, the F2200 only has one. The new head can reach 600dpi resolution, which should produce better detail and fine text and is considerably more productive. Epson is also planning to add the option to print to film from the F2200 so that it can double up as a DTF printer.
Ricoh sells a number of desktop DTG printers, including its Ri2000, which is essentially a faster version of the Ri1000 thanks to having a second print carriage with another set of four printheads for eight in total. The heads themselves are the Ricoh GH2220, with four set aside for white ink and the other four for CMYK.
Ricoh has now adapted the Ri2000 to create a prototype of a new DTG printer that’s able to print direct to polyester materials without sublimation. This in turn would appeal to the sportswear market where polyester is commonly used. Tomohiro Ikeda, general manager for Ricoh’s business management department, explains: “The big challenge for polyester is to stick the ink to the polyester thread because the material is so slippery that no ink will stick to it.” Ricoh’s solution is to lay down an optimiser, followed by white ink and then the colours. Ikeda adds: “Most of the ink sits on the surface but some is absorbed into the material.” Once the image has been printed, users will need to transfer the t-shirt to a separate heat press to cure the inks.
Brother, which makes its own printheads and ink, sells a number of DTG printers, including the GTX 600 which is aimed at higher-volume users. It features large ink tanks and automatic maintenance. This summer Brother launched a new Extra Colours version with two extra printheads to include orange and green. Stachetzki says this was to meet requests from those producers selling higher end textiles.
Brother has also demonstrated a new DTF machine, which is essentially a roll-to-roll version of the existing GTX Pro DTG printer, which allows the film to be passed straight through to the powder and processing unit to produce a finished roll in a single pass.
Aeoon has also targeted industrial users with its DTG printers, including the Kyo series. This uses multiple platens for higher productivity with the Kyo Plus able to produce up to 180 items per hour. There’s even a hybrid version that includes a screen printing unit.
Kornit has developed a range of DTG printers specifically aimed at high volume users. Kornit’s main DTG offering is the Atlas Max series, including the latest Atlas Max Plus that has gained some additional automation and can produce up to 150 garments per hour.
Kornit has also targeted the DTG polyester market with its Atlas Max Poly. This is based on the standard Atlas Max and uses the same Dimatix Starfire printheads. However, it has a different inkset, Olympia, combined with Neutrafix Pro fixation, and Poly Enhancer with Q.fix after the printing. It can produce up to 90 items per hour.
Earlier this summer Kornit introduced a much larger press, the Apollo, which is essentially a highly automated DTG printer capable of producing up to 400 garments per hour. Ronen Samuel, Kornit’s CEO says that productivity and total cost of ownership are important, noting: “We are more economical than any other solutions out there with run lengths of 500 and below and we have customers that are running at 3,000 and more.”
In conclusion, there’s room for both DTF and DTG technologies. While DTG prints offer excellent hand feel for natural fibres, printing direct to film is a cost-effective way of covering many different applications. But ultimately the choice comes down to productivity and profit margins for those applications.
