How Latex Inks Work
HP Latex inks are the first water-based inks capable of printing onto a wide range of coated and uncoated substrates. Water—which composes more than 60 percent of the inks—gives latex inks high surface tension, low viscosity and a vapor bubble that lasts only about 10 microseconds to drive a drop of ink out of a nozzle with the repeatable volume and velocity required for reliable high-quality printing.
Some competitors claim that HP Latex inks contain solvents, with the aim to create confusion—the ink contains water-soluble co-solvents. For sure, the ink is not simply pigments dissolved in water—otherwise PSPs would make ink at home. Latex inks are in fact very sophisticated formulations, containing many other components which ensure that the printhead stays wet, including surfactants that allow latex ink to better adhere to uncoated substrates as well as the anti-scratch agent that protects the print once cured, but none of these components are hazardous in the quantities used in the ink or to print.
As the ink carrier is water, inks are odor-less, non-toxic, non-flammable and non-combustible; they produce very low level of volatile organic compounds (VOCs) and require no special ventilation or handling. HP Latex inks are designed to be compliant with the most demanding environmental, health and safety regulations.
In the printing process, heaters evaporate some of the water, allowing the concentrated components and wetting agents to soften the surface of the substrate for better adhesion of the colorant layer.
An important innovation in the third generation of HP Latex Ink Technology has been the HP Optimizer, which enables printing at faster speeds with high quality by locking the pigment and not allowing them to be improperly mixed. In the curing zone, the latex particles melt to adhere to the substrate and create a protective film. The remaining liquids in the ink are evaporated to produce a completely dry and odorless print that can be immediately handled, finished and shipped. Prints can be displayed outdoors or indoors—even in sensitive environments, such as offices and hospitals.