Patent ID: 8007872

Claim:
An electrostatic coating method wherein a coating material feeding path for feeding an electrically conductive coating material or a fluid from a coating material feeding unit to a coating gun has a storage part for temporarily storing the electrically conductive coating material or the fluid and pushing out the stored electrically conductive coating material or the fluid toward the coating gun, and an insulating part for providing an electrical shield between the coating material feeding unit and the storage part; a fluid circuit is provided between the storage part and the coating gun; a coating material cartridge is detachably connected to the fluid circuit; and electrostatic coating is performed by applying a voltage when the electrically conductive coating material is fed from the storage part via the fluid circuit, or applying a voltage when the electrically conductive coating material is fed from the coating material cartridge via the fluid circuit, and feeding to the coating gun the electrically conductive coating material to which the voltage is applied, the method comprising the steps of: feeding the fluid from the coating material feeding unit to the storage part and storing the fluid when the electrically conductive coating material loaded into a coating material chamber inside the coating material cartridge is fed to the coating gun; and feeding the fluid in the storage part via the fluid circuit to a fluid chamber that is separated from the coating material chamber by a free piston in the coating material cartridge, whereby the free piston is pushed toward the coating material chamber, and the electrically conductive coating material in the coating material chamber is fed to the coating gun by the movement of the free piston.