What can you ink with?
A line up of different types of large format inks for inkjet applications
The recent years have seen many improvements in chemical engineering. This is good news for manufacturers of inkjet systems who are facing escalating demands for outputting images on all kinds of materials, from paper to vinyl to glass and different outdoor and indoor environments. Parallel to the development of faster inkjet engines, ink chemists have come up with variety of ink formulations for various applications such as signage, P-O-P displays, rigid substrates, fleet graphics, building wraps, billboards and so on. Here is a round up on different ink formulations available for inkjet applications:
Aqueous (water based) dye
Aqueous dye ink is highly expressive in colors but suitable only for indoor applications. In this ink formulation, the dyes are suspended in water. This ink is appropriate for many types of media, which can save running cost.
Black ink works well in shading screen. It has a wide color gamut and is printhead friendly. It can be used in applications where hi-res is a must such as art work. The major drawback for this type of ink is that the prints fade more quickly than other inks, particularly when exposed to sunlight. The major suppliers of this type of ink are Canon, Colorspan, Encad, Epson, Hewlett Packard, Mimaki and Mutoh. There are also a wide range of third party suppliers such as Prism that offers three distinct sets of these inks for various market segments.
Aqueous (water based) pigment
In this type of ink, different grades of pigment are suspended in water, which makes it excellent in color expression and light resistance. It is suitable for a wide range of indoor applications. It can be used for outdoor applications but must be used with the right media and must be laminated, especially on vinyl.
Where print longevity is an important consideration, aqueous pigment inks, when properly matched to the media, are the best choice and they can last up to 100 years. While some of the newer aqueous inkjet media are available with waterproof properties, most are designed for high-quality indoor applications. The color gamut in this type of ink is not as high as aqueous dye, which makes it less favorable for art works. The major suppliers of aqueous pigment inks are Canon, Colorspan, Encad, Epson, Hewlett Packard, Mimaki, Mutoh, and Roland DGA. Strong third party suppliers such as DuPont Fusion also offer this type of inks to the market. There is also an IR- curable version of this ink for Encad VinylJet device, which uses an infrared heating system. Encad has developed this ink with the cooperation of DuPont.
Dye sublimation inks
Dye sublimation is a process that uses a special heat sensitive dye to print graphics and text onto paper. This is called a transfer. The paper is then placed on a sublimatable item and both are placed into a heat press for about 20-45 seconds at 180-230 degrees. Dye sublimation ink has been used in printing on materials like tiles, wood, polyester, nylon, plastic, etc. Dye sublimation ink has the characteristic of dyes. It is different with digital printer inks. The brilliance and clearness of an image has been influenced by sublimation of the ink. There are many third party suppliers of this type of ink. Epson and HP are also major suppliers of dye ink cartridges.
Specially formulated for use in wide format markets using plotters as the output device. Usually popular in the field of advertisements such as P-O-P posters, backlit films, banners and other graphic arts applications, where 100% water resistance and medium range exposure to sunlight is of great importance. One of the major applications for this type of ink is engineering drawings. The number of media for this type of ink is more limited than for aqueous inks. The suitable media for oil based inks are PVC film - with and without adhesive backing, canvas - thick and thin, silk material and other plastic or plastic-coated media. The major suppliers of this ink are DGI, Seiko, Infotech and Xerox.
Solvent inks (mild and aggressive)
There are two types of solvent inks:mild and aggressive. MS ink (also called soft or eco-solvent) is a mild solvent ink that has low odor and high weather resistance. MS ink should print on media (vinyl, tarpaulin) coated with receiving layer developed for MS ink. MS ink has a very low-volatility formulation. These inks are used in out door applications. But their out door durability is limited to two years without lamination. The major benefit is its environmentally friendly formulation and it does not need special ventilation systems. However, the ink uses very slow-drying liquids as the carrier fluid. Therefore, printers that use these inks have several heaters fitted to aid with ink drying. The major suppliers of this ink are Mimaki, Mutoh and Roland.
On the other hand, aggressive solvent inks (hard or true solvent) generally dry faster and need fewer heaters in the system. However, they need ventilation systems to minimize VOC’s. These inks are widely used by the signage industry to produce billboards, fleet graphics, and outdoor banners. True solvent inks can be used with a variety of low cost, uncoated substrates to produce graphics. With the right media combination, they can last up to five years outdoors. The major suppliers are Colorspan, DGI, Gandinnovations, Mimaki, Mutoh, NUR, OCE, Scitex, and VUTEK.
UV curable ink is a 100% solid system: that is, it essentially does not contain solvents that must evaporate during the curing phase. The cure takes place through the interaction of the ink ingredients and a strong UV (ultra violet) light source in a dryer. Since UV contains little or no solvent, there is a lot of interest in using it because of the lack of VOC’s (volatile organic compounds). The main application for these inks is printing on rigid substrates. But it can be used on a wide verity of substrates. The outdoor durability of this ink is excellent and does not need lamination. It is an ideal ink for flatbed printers. The major suppliers of UV curable inks are Durst, Inca Digital, NUR, Scitex, VUTEK, and Zund.