Abstract: An example of a printing fluid supply connector is described that has a first connector and a second connector, where each of the first and second connectors is to fluidly connect to a respective replaceable reservoir of printing fluid. The printing fluid supply connector also has an outlet to fluidly connect to a printer and a selector to selectively fluidly connect one of the first and second connectors to the outlet in response to an electrical control signal or to fluid pressure at the first and second connectors.

Abstract: Example methods for the maintenance of printheads are provided, the printheads comprising a reservoir containing a printing fluid with particles in suspension, and a nozzle plate. Example methods may comprise capping the nozzle plate of the printhead, and rotating the capped printhead. Example maintenance devices for printheads are also provided,comprising a support with a socket to attach a printhead to the support, a drive unit to rotate the support about a rotation axis, and a control unit connected to the drive unit to perform a predetermined rotation cycle.

Abstract: A printing fluid circulation system is described. The system comprises first and second reservoirs, an outlet to supply printing fluid to a fluid inlet of a printhead, an inlet to receive printing fluid from a fluid outlet of the printhead, and a supply system. The supply system is to operate in a first mode to concurrently supply printing fluid from the first reservoir to the outlet and from the inlet to the second reservoir, and in a second mode to concurrently supply printing fluid from the second reservoir to the outlet and from the inlet to the first reservoir.

Abstract: A print head priming system comprises a vent closure section to close a vent, where the vent is to compensate backpressure in a print head. An inlet to receive pressurized gas from a source of pressurized gas is to provide the pressurized gas to the print head. A pressure relief valve is to open in response to pressure in the print head reaching or exceeding a predetermined value by the provision of gas to the print head by the source of pressurized gas.

Abstract: A print head priming system comprises a vent closure section to close a vent, where the vent is to compensate backpressure in a print head. An inlet to receive pressurized gas from a source of pressurised gas is to provide the pressurized gas to the print head. A pressure relief valve is to open in response to pressure in the print head reaching or exceeding a predetermined value by the provision of gas to the print head by the source of pressurised gas.

Abstract: A print head priming system comprises a vent closure section to close a vent, where the vent is to compensate backpressure in a print head. An inlet to receive pressurized gas from a source of pressurized gas is to provide the pressurized gas to the print head. A pressure relief valve is to open in response to pressure in the print head reaching or exceeding a predetermined value by the provision of gas to the print head by the source of pressurized gas.

Abstract: In one implementation, a substance removal apparatus may include a collection unit and a removal unit. The collection unit may have a structure forming a channel and an inlet to receive an exhaust from a print system. The removal unit may separate a substance from the exhaust and transfer heat from the exhaust to the print system. The removal unit may include a heat exchanger and an impaction mechanism.

Abstract: A print head priming system comprises a vent closure section to close a vent, where the vent is to compensate backpressure in a print head. An inlet to receive pressurized gas from a source of pressurised gas is to provide the pressurized gas to the print head. A pressure relief valve is to open in response to pressure in the print head reaching or exceeding a predetermined value by the provision of gas to the print head by the source of pressurised gas.

Abstract: In one implementation, a substance removal apparatus may include a collection unit and a removal unit. The collection unit may have a structure forming a channel and an inlet to receive an exhaust from a print system. The removal unit may separate a substance from the exhaust and transfer heat from the exhaust to the print system. The removal unit may include a heat exchanger and an impaction mechanism.

Abstract: Ink separators are described herein. One example ink separator is described, which includes an ink receptacle to receive ink aerosol particles, a surface within the ink receptacle to change a direction of an airflow entraining the ink aerosol particles and cause at least a portion of the ink aerosol particles to combine to form ink droplets on the surface, and a chamber adjacent the surface to receive the airflow including the ink droplets and at least some of the ink aerosol particles, wherein the chamber includes at least two flow paths to separate the airflow and the ink aerosol particles from the ink droplets by directing the airflow and the ink aerosol particles to an aerosol collection port and the ink droplets to an ink droplet collection port.

Abstract: In one embodiment, a servicing article comprises a web comprising a first material impregnated with a servicing fluid, the servicing fluid including a solvent that does not evaporate at ambient printer conditions, and a plurality of physical barriers within the first material, extending approximately across the first material's width, to restrict servicing fluid migration lengthwise along the web.

Abstract: Ink separators are described herein. One example ink separator is described, which includes an ink receptacle to receive ink aerosol particles, a surface within the ink receptacle to change a direction of an airflow entraining the ink aerosol particles and cause at least a portion of the ink aerosol particles to combine to form ink droplets on the surface, and a chamber adjacent the surface to receive the airflow including the ink droplets and at least some of the ink aerosol particles, wherein the chamber includes at least two flow paths to separate the airflow and the ink aerosol particles from the ink droplets by directing the airflow and the ink aerosol particles to an aerosol collection port and the ink droplets to an ink droplet collection port.

Abstract: In one embodiment, a servicing article comprises a web comprising a first material impregnated with a servicing fluid, the servicing fluid including a solvent that does not evaporate at ambient printer conditions, and a plurality of physical barriers within the first material, extending approximately across the first material's width, to restrict servicing fluid migration lengthwise along the web.