The function of flash spray is that in order to prevent the print head from clogging caused by ink, the print head will spray some ink every period to keep the nozzle clean, this is the flash spray. We know that the print head should be moist all the time even when the printer is not on work. UV printer ink contains solvent, ink will volatilize on the nozzle, it will freeze on the nozzle, so it will plug the nozzle. Flash spray is to spray ink fleetly under this circumstance, wash away the solidification, keep the print head moist. If the print head can not flash spray, with time goes by, it will seriously plug the nozzle.