Darin Boling / CorrStream Technical Specialist Digital Print Systems Maintenance and Inspection Print Head Ink Delivery System Hardware and Software Substrate Transport System Darin Boling / CorrStream Technical Specialist

Print Head Print Head Surface Wipe and purge Wipe surface of print heads using a liberal amount of approved flush and microfiber lint free cloth. Always wipe in the same direction and use a clean portion of cloth for each wipe. Inspect surfaces of heads for signs of damage e.g. scratches, Purge is function that increases the jetting pressure to dislodge trapped particulates within the nozzle orifice. It is also used to remove air from the ink.

Print Head Capping station A capping station is typically used to provide cover to protect the heads when not in use and prevent ink from drying in the nozzles or on the surface of the head. This also provides containment for ink during purge cycles where it is diverted to a waste container Regular cleaning of the capping station is required to prevent the possible buildup of dried in that could scratch the surface of the heads. Periodic draining of the waste tank would be required and proper disposal methods would be necessary in accordance with ink manufacturers SDS.

Print Head Nozzles 600dpi 2656 nozzles per head, 664 per quadrant. Nozzle test (jet state) print images are developed by the manufacturer and are used to inspect the status of each nozzle. Common issues. Clogged or missing jets Diverted Jets

Print Head Alignment Alignment is the process of performing adjustment to angle, stitch and delay to obtain a linear XY relation between print head arrays (color Bar) and color. Images are developed by the manufacturer to assess, as well as assist, print head alignment. Angle Angle adjustment could be either a manual or automated process performed thru the software and used to adjust the linear. Stitch Stitch is the overlap between heads and is aligned by making linear adjustment to heads

Print Head Delay Heads are usually staggered and offset from one another. Delay is a timing adjustment in the firing to obtain a linear alignment between heads within a color bar and the color bars to each other. Alignment can change as a result of fluctuations in temperature and humidity. Therefore, environmental control is essential to maintain proper alignment. Alignment should be assessed regularly and will most likely need to be performed whenever a print head has been replaced.

Ink Delivery System The ink delivery system is sometimes referred to as the Hydraulic Pneumatic Module or HPM and each color will have a dedicated HPM. The module usually houses a filtration system, degassing lung, ink pump and a meniscus system which requires vacuum pumps and air filtration. Ink is pumped from the container through a filtration system and degassing lung before it is delivered to a smaller tank or tanks where it is stored before delivery to the heads. Maintenance involves periodic replacement of all filters and degassing lungs as well as visual inspections for leaks

Hardware and Software Very minimal maintenance is required for the software. Most issues are handled by the manufacturer using remote viewing software especially since it is usually proprietary. Therefore, Internet access would be a requirement Hardware components are typically replaced whenever a failure occurs There are commonly three systems involved with digital printing Print Engine Controls Motion Controls Rip Software and Color management

Belt Transport System Feeder Feeders transport the corrugate onto the conveyor belt and may or may not have a sheet cleaning and ionization system between it and the belt. Movement of the board and components will most likely be monitored using proximity sensor and/or laser detection systems General Maintenance Bearing lubrication Visual inspection of moving components. Cleaning the ionizing bar if equipped. Regular housekeeping to remove debris from areas that could cause false sensor activation and jams.

Belt Transport System Belt Transport A perforated transport belt is used to hold the board in place. This can be problematic if the sheets are not fed properly. Exposed holes can cause windage issues. Windage is when air current passes between the sheet and print head causing the ink to be drawn away from the surface and leaving streaks in the image. Sheet placement should be controlled in such a way that no holes are exposed in the gaps between sheets. General maintenance Bearing lubrication Visual inspections to belt and moving components Cleaning belt surface to remove any build up over overspray Cleaning or replacement of vacuum system filters Sensor alignment and cleaning  

Thank You Darin Boling CorrStream Technical Specialist