Latex printing technology

Latex printing technology has only been out for a few years, and it is booming and becoming a very popular printing method. The quality it yields can be breathtaking, and it may have some advantages over solvent. I wanted to highlight some of the differences between the two technologies (latex and solvent ink), and the pros and cons between them as well.

One thing latex brought to the playing field when it was introduced was how eco-friendly it is. The inks used are better for the environment, and they are just as vibrant as some solvent printers. The latex printer does not require a ventilation system or a scrubbing system like some solvent printers do, and VOC’s are virtually non-existent with this printer.
Getting down to the basics, the main difference between a solvent based printer and latex based hinge on two factors. The first one is how it delivers ink to the substrate, and more specifically, what the inks consist of. They also differ how the substrate reacts when the inks are applied.
Solvent inks and latex inks have totally different chemistry. In solvent inks, the ink vehicle is comprised of pigment (color), plus an etching agent which helps ‘etch’ out the media when it has been applied, and an evaporating agent which assists in drying the ink out. The ink is ejected out of the print head, hits the media, the etching chemical then etches (or creates a void) into the media where the ink will reside, and then the heaters on the printer help evacuate the drying agent in the ink. During the drying process, the liquid parts of the ink will evaporate, leaving the pigment in place.
Latex ink consists of 80% water and pigment. Latex does require quite a large drying unit to cure the ink to the media and help evacuate the water, but the ink comes out 100% dry. Solvent prints requires a period of 12 to 24 hours to take place so outgassing may occur. If you don’t do this step, and move directly to laminating, little bubbles will appear in the laminate, thus defacing the print.
The delivery methods in both units are pretty close to the same, however, when the latex printer needs new print heads, I can install them myself for a fraction of the cost. When you look at solvent units, the head replacement is typically very expensive, plus a technician is required to do the replacement. On the flip side of that, the heads in a solvent machine will outlast those in latex units 5 to 1.
One thing I don’t like about our latex HP L25500 is the paper path. It takes practice to get the unit loaded, but it can be done in three minutes time. The solvent ink printers I have seen have a ‘straight thru’ path, takes the challenges out of loading the unit.