April '17

For the Business of Apparel Decorating

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76 || P R I N T W E A R A P R I L 2 0 1 7 clogged ink line, which is tough to break free of and almost always results in chang- ing your ink line(s). DAMPERS OR CARTRIDGES Since ink lines in certain printers directly connect to the dampers or cartridges, de- termining if the issues are either the ink lines or dampers takes a little trial and error. Some D2 systems have a cartridge with ink lines attached to them. The car- tridges sit on top of the print head itself. These types of cartridges have an elec- tronic chip on the end. A damper would not have this chip and will perform much better than a cartridge. When the print head moves, the internal pressure increases and decreases rapidly, and a damper equal- izes this pressure since the source is coming from the damper itself. As ink flows into the damper, it goes through a filter, a reser- voir, then the print head. If the ink is not properly filtered or has dried ink from an open system, these filters can clog quickly and cause nozzles or full channels to drop out. This is why a proper ink source us- ing high-quality and properly filtered inks makes a tremendous difference in perfor- mance. At the beginning of your day, if a nozzle check is performed and a channel is not printing, use the proper procedure from your manufacturer to recover nozzles. If after they have been recovered and the channel drops out shortly after you begin printing, chances are the damper is not performing correctly. Recover the chan- nel again and if the same results are seen, change the damper. PRINT HEAD(S) There are several types of print heads on the market, one of which utilizes a single head with eight channels of ink. The top portion of the print head is called the manifold. This is where the spikes push into the dampers and allows the ink to be released into the head. As the ink travels through the manifold, it passes through a filter before it reaches the head itself. If the ink lines and dampers are not clogged but you cannot recover the ink channel or most of the nozzles in that channel, there is a good possibility the manifold filter is clogged. There are methods to recover the manifold called back flushing. If this doesn't solve the issue, changing the mani- fold itself should solve the problem. Of course, if the manifold isn't the issue either, it may be time for a new print head. Most print heads have more than 1,000 nozzles on the surface of the nozzle plate. Each nozzle is the thickness of a human hair, so it's no wonder improper ink han- dling can cause ill effects. It's not always the ink itself but air bubbles trapped be- D2 SYSTEMS & MAINTENANCE The test on the left shows an example of a poor nozzle check while the image to the right highlights a good nozzle check. This image shows an ink delivery system test. Ink starvation will cause white channels to drop out, as seen here.

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