Abstract: In one example, an LEP printer includes a belt rotatable in a loop, a series of multiple printing units along the belt each to apply an LEP ink color separation to the belt, a first heater to dry the color separations on the belt to a molten film at a drying temperature, a second heater to heat the molten film on the belt to a transfer temperature higher than the drying temperature, and a pressure roller near the belt to press a printable substrate against the belt at a nip between the pressure roller and the belt.

Abstract: In an example of the disclosure, a system for identification of gas conveyance malfunctions includes a channel situated to convey a subject gas, a condenser in fluid connection with the channel, and a heat blower positioned in fluid connection with the channel. The heat blower is to heat the subject gas, and to cause the subject gas to move through the channel towards the condenser. The system includes a temperature sensor situated to take a temperature reading of the subject gas within or adjacent the channel. The system includes a controller, operatively connected to the temperature sensor. The controller is to identify a malfunction event for the heat blower, the condenser, or the channel based upon a comparison of the temperature reading to a threshold temperature.

Abstract: According to an example, a mixing device comprises a first chamber including a solute addition member and a first mixer, a second chamber including a second mixer, a printing fluid pump, and a controller operatively connected to the solute addition member, the pump, the first mixer, and the second mixer. The controller is to control the pump to move printing fluid towards the printing fluid tank based on a printing fluid density level in the printing fluid tank, to control the solute addition member to add solids based on the printing fluid density level, and to control the first mixer and the second mixer to mix the added solids with the printing fluid moved by the pump.

Abstract: In an example of the disclosure, a heat exchange and flame arrest device for use with a subject gas includes tubing arranged to traverse a core, with the tubing defining a cooling fluid pathway. The core includes a gas flow inlet, a set of cooling fins, and a gas flow outlet. The gas flow inlet, the set of cooling fins, and the gas flow outlet collectively form a gas flow pathway for a subject gas. Each cooling fin of the set is positioned to form a gap between that cooling fin and an adjacent cooling fin. The gas flow inlet is to receive the subject gas. The combination of the gap between each cooling fin of the set and the cooling capacity of the cooling fluid pathway is sufficient to, if the subject gas has ignited, lower temperature of the subject gas to below autoignition temperature.

Abstract: In one example, an LEP printer includes a belt rotatable in a loop, a series of multiple printing units along the belt each to apply an LEP ink color separation to the belt, a first heater to dry the color separations on the belt to a molten film at a drying temperature, a second heater to heat the molten film on the belt to a transfer temperature higher than the drying temperature, and a pressure roller near the belt to press a printable substrate against the belt at a nip between the pressure roller and the belt.

Abstract: In an example of the disclosure, a system for identification of gas conveyance malfunctions includes a channel situated to convey a subject gas, a condenser in fluid connection with the channel, and a heat blower positioned in fluid connection with the channel. The heat blower is to heat the subject gas, and to cause the subject gas to move through the channel towards the condenser. The system includes a temperature sensor situated to take a temperature reading of the subject gas within or adjacent the channel. The system includes a controller, operatively connected to the temperature sensor. The controller is to identify a malfunction event for the heat blower, the condenser, or the channel based upon a comparison of the temperature reading to a threshold temperature.

Abstract: A printing apparatus has a transfer member to receive an image and transfer the image to a substrate, and an airflow management unit disposed adjacent to the transfer member to define a channel between the transfer member and the airflow management unit. The airflow management unit has an injection mechanism to inject airflow into the channel, a suction mechanism to remove the airflow from the channel, and a vortex generator to generate a vortex within the channel.

Abstract: In an example of the disclosure, a heat exchange and flame arrest device for use with a subject gas includes tubing arranged to traverse a core, with the tubing defining a cooling fluid pathway. The core includes a gas flow inlet, a set of cooling fins, and a gas flow outlet. The gas flow inlet, the set of cooling fins, and the gas flow outlet collectively form a gas flow pathway for a subject gas. Each cooling fin of the set is positioned to form a gap between that cooling fin and an adjacent cooling fin. The gas flow inlet is to receive the subject gas. The combination of the gap between each cooling fin of the set and the cooling capacity of the cooling fluid pathway is sufficient to, if the subject gas has ignited, lower temperature of the subject gas to below autoignition temperature.

Abstract: In an example, a heated air knife and a negative pressure component are controlled to heat a subject gas and direct the subject gas through an evaporation channel at a target gas velocity that is above a flame propagation velocity for the subject gas. The evaporation channel is defined in part by a first surface, a nozzle of the air knife, a mixing zone, and a second surface substantially opposite the first surface.

Abstract: In one example, an exhaust hood includes an enclosure having a perimeter defining an exhaust area and a fluid flow path. The fluid flow path includes a perimeter intake slot through which air is sucked into the flow path during an exhaust operation and a flow channel in fluid communication with the perimeter intake slot and configured to carry fluid away from the intake slot and out of the enclosure.

Abstract: A printing apparatus has a transfer member to receive an image and transfer the image to a substrate, and an airflow management unit disposed adjacent to the transfer member to define a channel between the transfer member and the airflow management unit. The airflow management unit has an injection mechanism to inject airflow into the channel, a suction mechanism to remove the airflow from the channel, and a vortex generator to generate a vortex within the channel.

Abstract: An example system includes a conveyor. The conveyor is not a photoconductor. The system also includes a developer unit. The developer unit is to internally concentrate printing liquid. The developer unit also is to deliver the printing liquid to the conveyor. The system includes a wiper in contact with the conveyor. The wiper is to remove the printing liquid from the conveyor.

Abstract: A print apparatus is disclosed. The print apparatus comprises a container-receiving unit for receiving a reusable print agent container; a print agent reservoir for storing print agent to be consumed by the print apparatus during a printing operation; a pump for transferring print agent between a reusable print agent container positioned in the container-receiving unit and the print agent reservoir; and processing circuitry. The processing circuitry is to operate the pump to transfer print agent of a first concentration from the reusable print agent container to the print agent reservoir; and, responsive to determining that a volume of print agent of the first concentration in the reusable print agent container has fallen below a threshold volume, operate the pump to transfer a volume of print agent of a second, lower concentration from the print agent reservoir to the reusable print agent container. A method and a machine-readable medium are also disclosed.

Abstract: In one example of the disclosure, a first transfer of ink is made from a photoconductor to a blanket in contact with the photoconductor. The blanket is to cycle along a path. The first transfer occurs at a first arc of the blanket path. A second transfer of the ink is made from the blanket to a media in contact with the blanket. The second transfer occurs at a second arc of the blanket path. A heat source located adjacent to a third arc of the blanket path is utilized to heat an external surface of the blanket. The heating is to occur following the second transfer of the ink.

Abstract: A print apparatus is disclosed. The print apparatus comprises a container-receiving unit for receiving a reusable print agent container; a print agent reservoir for storing print agent to be consumed by the print apparatus during a printing operation; a pump for transferring print agent between a reusable print agent container positioned in the container-receiving unit and the print agent reservoir; and processing circuitry. The processing circuitry is to operate the pump to transfer print agent of a first concentration from the reusable print agent container to the print agent reservoir; and, responsive to determining that a volume of print agent of the first concentration in the reusable print agent container has fallen below a threshold volume, operate the pump to transfer a volume of print agent of a second, lower concentration from the print agent reservoir to the reusable print agent container. A method and a machine-readable medium are also disclosed.

Abstract: Aspects presented herein are directed towards a carrier evaporator for a Liquid Electrophotography Printing (LEP) system. In an example, the carrier evaporator provides a hot air supply to absorb an evaporated carrier liquid resulting in first air flow comprising a carrier vapour, an evacuator to evacuate at least a portion of the carrier vapour, a heat exchanger to decrease a temperature of the remaining carrier vapour thereby transforming the first air flow to a second airflow comprising carrier particles, and a filter to remove the carrier particles from the second air flow.

Abstract: An example apparatus includes a conveyor. The apparatus also includes a first developer unit. The first developer unit is to concentrate first printing liquid. The first developer unit also is to deliver the first printing liquid to the conveyor. The apparatus also includes a second developer unit. The second developer unit is to concentrate second printing liquid. The second developer also is to deliver the second printing liquid to the conveyor to form a thick layer of printing liquid comprising the first and second printing liquid.

Abstract: An example method of collecting liquid carrier from a vapour in a printing system includes: heating a vapour carrying a liquid carrier and passing the heated vapour carrying liquid carrier through a volume of liquid carrier. Liquid carrier carried in the heated vapour condenses into the volume of liquid carrier as it passes through the volume of liquid carrier.

Abstract: An example system includes a conveyor. The conveyor is not a photoconductor. The system also includes a developer unit. The developer unit is to internally concentrate printing liquid. The developer unit also is to deliver the printing liquid to the conveyor. The system includes a wiper in contact with the conveyor. The wiper is to remove the printing liquid from the conveyor.

Abstract: In one example of the disclosure, a first transfer of ink is made from a photoconductor to a blanket in contact with the photoconductor. The blanket is to cycle along a path. The first transfer occurs at a first arc of the blanket path. A second transfer of the ink is made from the blanket to a media in contact with the blanket. The second transfer occurs at a second arc of the blanket path. A heat source located adjacent to a third arc of the blanket path is utilized to heat an external surface of the blanket. The heating is to occur following the second transfer of the ink.