Inkjet printing method and inkjet printing apparatus

An inkjet printing apparatus, comprising:

• an ink storage unit that contains ink;
• a discharging unit having a nozzle forming surface having a nozzle from which the ink is discharged;
• a lid member configured to cover the nozzle forming surface;
• and
• a supplying unit configured to supply the ink from the ink storage unit to the discharging unit,
• wherein
• the ink comprises a silicone-based surfactant, an organic solvent, a resin, and water,
• the ink satisfies the following relational expression (1),
• σ=a×Log10(t)+b Expression (1)
• where, in the expression (1), a and b represent constants, the constant a is −17.5 or more and −5.9 or less, the constant b is 38.0 or more and 68.1 or less, σ represents dynamic surface tension of ink (unit:
• mN/m) at 25° C., and t represents time (unit:
• millisecond),
• the supplying unit includes,
• a pressure controller configured to freely control a pressure between the discharging unit and the ink storage unit, in a closed space formed when the lid member covers the nozzle forming surface;
• and
• an atmosphere releaser configured to set the pressure between the discharging unit and the ink storage unit to be the same as atmospheric pressure, in an open space formed when the lid member does not cover the nozzle forming surface,
• a negative pressure difference between the ink storage unit and the discharging unit before discharge of the ink is 70 mmAq or more and 120 mmAq or less,
• a negative pressure difference between the ink storage unit and the discharging unit during discharge of the ink is 30 mmAq or more and 80 mmAq or less, and
• the negative pressure difference between the ink storage unit and the discharging unit before discharge of the ink is equal to or greater than the negative pressure difference between the ink storage unit and the discharging unit during discharge of the ink.