PREVENTION OF CLOGGING IN INK JET RECORDING DEVICE

PURPOSE:To prevent simply and effectively clogging of an ink jet recording device due to drying and hardening of the ink and other causes by covering the nozzle section of an ink jet head with an ink evaporation preventive liquid after charging air foam into the nozzle section during stopping ink injection. CONSTITUTION:Firstly, after the valve 11 of an ink jet recording device is closed to stop injection of the ink, the valve 12 is opened at once to put air foam 20 into the inside of the ink jet head 1 to develop an ink film 21 over the hole section of the nozzle 2. Next, the pressure of the ink in the head 1 is raised a little to expand the ink film 21 outwardly, and this ink film 21 is washed away by applying an ink drying preventive liquid (preferably wetting agent constituting the ink). Furthermore, by lowering the ink pressure in the head 1 to its original pressure, the ink film 21 is substituted for the film 22 of the ink drying preventive liquid to prevent clogging of the ink. EFFECT:Reliability of the device is improved in a great deal.