Vacuum Pressure System An Operator’s Guide 1
ColorSpan Legacy solvent and UV-curable ink printers use a vacuum and pressure system applied to the printheads. This document explains the system from the point-of-view of a printer operator. The goal is to assist users of these printers to troubleshoot small problems, prevent larger issues, and communicate accurately to ColorSpan Technical Support when things do go wrong an help is needed.
How Pressure is Used Air pressure is used for two purposes. The first and more frequent purpose is as part of the Purge cleaning process. When pressure is applied to the reservoirs, air displaces the ink. The ink has nowhere to go but out the inkjet nozzles on the bottom of the printheads. The ink under air pressure will try to dislodge any partially solidified ink or foreign particles that may have accumulated inside or around the inkjet nozzles.
Filters While the blue “cup” is not a filter, there are several air filters used on the VP system. These disk-shaped filters are about 1” (2.5cm) in diameter. One filter is found in-line on the long vacuum tube. The remaining filters (2 of them) are inside the V/P assembly, underneath the metal enclosure. Two views of the air filters used in the Vacuum/Pressure assembly. On the left is the in-line filter, removed from the vacuum line. On the right is the input filter inside of the V/P assembly.
On the HP Scitex FB910 (ColorSpan 9840uv), the V/P assembly is just inside the output-side user cabinet, shown below. The regulator is located in the lower-left corner of the assembly, visible as a grey circle with a brass-colored metallic center. Insert the screwdriver in the metal center and make small turns to the regulator and wait for the control panel to update to see the effect.
Ink drips out of the printheads As noted at the beginning of this document, the purpose of the vacuum system is too keep ink suspending in the printhead reservoirs. When ink drips out, it signals a problem. The source of the problem may be any one (or more) of the following: 1. Vacuum level is too low (regulator needs adjustment). 2. Leak in the system somewhere. • Hole in tube • Tube loose around a fitting • Fitting loose in its receptor 3. Pinched tube. 4. Stuck valve.
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