Method of and apparatus for cleaning ink jet head.

摘要

Disclosed are a method of and an apparatus for cleaning a plurality of nozzles of an ink jet head 20. This cleaning method comprises a step of covering a nozzle surface 21 formed with the plurality of nozzles with a cap 4; a step of depressurizing an air space formed between the nozzle surface 21 and the cap 4 by use of a depressurizing element 36 to suck the inks from the nozzles; a step of stopping the depressurization by the depressurizing element 36;a step of keeping the nozzle surface covered with the cap so that the inks jetted from the nozzles due to the depressurization wet-spread over the entire nozzle surface by capillary action; and a step of withdrawing the cap 4 from the nozzle surface 21. Further, in this cleaning apparatus, a contact angle theta 1 between the ink and the cap internal surface and a contact angle theta 2 between the ink and the nozzle surface are set to 90 DEG or smaller and also set such as theta 2