Solvent is dead, long live solvent…

In many a history book we have read the lines ‘The King is Dead, Long Live the King’ – the old king dies and the new king is welcomed and becomes the greatest king. The history and evolution of printing technology and processes could be compared with this premise. In the Solvent printing business this has been happening. The older ink technologies which were smelly and poor quality but seen as wonderful during their time are being replaced with a new generation of inks which are bright, odourless and long lasting. The question is…‘Is Solvent the correct technology for the sign making industry at this moment in time?’

There are many new ink technologies that have come to market in the last few years. The main ones are Latex (resin-based inks) and UV ink technology. Latex has been on the market for about 5-6 years and has developed into a niche market ink for many printing segments. Mimaki is the only company apart from HP that has developed Latex. We see the speciality market as a significant opportunity where the use of Latex is an advantage to all in the supply chain. The indoor usage of Latex has a supreme advantage because Latex is a non-VOC and HAPS ink. This makes this ink ideal for interior decoration such as the wallpaper, indoor signage and print proofing markets. This last segment is something that has recently been developed by Mimaki by adding Orange and Green Latex inks to the portfolio so that the colour gamut is bigger than offset. The latest generation of Latex ink makes it possible to have a premium solution for commercial proofing specifically on many uncoated substrates. Latex also offers printing transparencies because of the availability of Latex white inks. It is possible to use transparencies with a clingfilm effect on a Latex printer. The printer can also use colour/white/colour printing to make a perfect backlit image for day and night printing with this technology.

So if Latex is the solution why stay with Solvent? Before we answer this, let’s look at another ink technology, UV curing inks. These inks are appearing in many markets and for many different applications. In the beginning UV inks were cured by big hot UV lamps that hardened the inks by changing the monomers to polymers. This resulted in great inks for rigid substrates but not useful for roll to roll media due to the fact that the UV inks were not really flexible. This has changed in the last few years. The inks today are much more flexible and can even be used for car-wrapping giving about 200% stretch. Now it’s possible to print all roll-to-roll media with UV ink and dismiss Latex and Solvent all together.
So why go with solvent? Well, in the first instance it is a choice as UV printing can be a more expensive production method. The reason for many users choosing to go with UV printing is still the advantages it has to offer when printing on rigid printing substrates. There are of course some hybrid solutions on the market, but these are not very effective. Printing roll-to-roll on an expensive flatbed printer is not only inefficient, but I believe you should use the printer for the purpose it’s made for. You can always buy a smaller roll-to-roll printer that is faster and better for the price of the roll option on a flatbed printer. At Mimaki we don’t have a roll option for this exact reason. Why pay 20K euros for something that will give you say 20sqm/h when you can get a printer that can do 100sqm/h for the same price?

So UV printing has taken a part of the Solvent and Latex markets, but it still may not be the right solution for many markets and applications. It is great for glass, wood, metals, cardboard, foam and forex types of media that don’t fit into a roll-to-roll printer. One of the other problems with UV is that the adhesion is not always as good on all substrates. Surface tension is very important for perfect adhesion so you can’t print on all substrates – although adding a primer to the substrate can solve this problem. Also flaming, plasma and corona treatment all help with the adhesion of inks, but it is still a trial and error way of printing. Lately we have seen new technologies that can replace Solvent printing but for some reason this has still not happened. There must be a reason, right? Yes, there is – but I will get to that later.

So is there more? You bet! Mimaki has a new technology – it’s called SUV or Solvent UV hybrid ink. This new technology combines the best of both worlds. The Solvent ink side gives adhesion on vinyl that is very good and the UV ink part achieves the gloss and colourful finish you desire. This type of UV ink component is also flexible so you can really work with it from a roll. The other advantage is that you don’t need to wait before you start working with it. You can laminate it without waiting. The advantage with this ink technology is that there is enough time for the pigment particles inside the ink to fall and laydown on the substrate giving it a very flat surface thus giving it a great scratch resistance and also the best reflection of the widest colour gamut you can think of. The results are stunning. As the ink has a big UV pigment component the weather and light resistance are also extremely good. Three months outdoors on a vinyl substrate is possible without any worries. This is therefore perfect for short term outside jobs with no need to laminate. With this element you can save a big part of the production cost.
Looks like a winning technology? Mimaki believes it – SUV is on its way!

Although this is a great technology, there is still a big market for Solvent inks. The more affordable production costs, the diverse availability of substrates and the high speeds of printing still make Solvent the king of printing for wide format.

Today Solvent based inkjet printers can print to very high quality standards on banners up to 100sqm/h. It is possible to print perfectly onto transparencies with white Solvent ink – also silver inks give metallic effects that are not available in the other technologies. The Solvent solutions work and are a lot cleaner than commonly known. Even with the new reach laws and environmental considerations we still have a great technology in our hands. Just think – what other technology will let you print and cut on one single machine? What other technology can you use for a car wrap and a retail poster or community signage by just changing the media? What print technology will let you print 100sqm/h for less than 20k euros? There are no technologies that have yet been able to replace the Solvent technology on all of these fronts.

So long live the KING – Solvent is still KING of Wide Format.

Mike Horsten
General Marketing Manager EMEA Mimaki at Mimaki Europe B.V.

Mike Horsten Mimaki Europe