A common white ink problem is that the nozzle test looks normal at the beginning, but missing nozzles appear after printing for a while.
If the problem keeps getting worse, an entire ink channel may eventually stop printing.
In many cases, the cause can be the white ink itself.
Hard Sediment Can Block the Ink Path
Poor raw materials or an unbalanced ink formula can create hard sediment inside the white ink.
This is different from normal settling.
Normal white ink pigment can usually be mixed again through proper stirring or circulation.
Hard sediment may stay in clumps even after shaking.
These particles can collect around the printhead cap or ink path.
Once enough material builds up, ink flow to the Printer Printhead becomes unstable.
That is when missing nozzle lines may start appearing.
Do Not Keep Forcing Cleaning Cycles
Repeated ink pulling and cleaning may make the situation worse.
If hard particles are already sitting near the printhead cap, strong or repeated cleaning can pull more contamination toward the nozzle channels.
This may turn a partial blockage into a more serious clog.
The problem is no longer just normal nozzle maintenance.
Replace the Problem Ink
If hard sediment is confirmed, stop using that batch of UV ink.
Replace it with compatible white ink.
The hard sediment around the cap and ink path should also be removed using the printer manufacturer's approved maintenance method.
After the system is clean, run the normal ink-loading procedure and check the nozzle test again.
A good Printer Troubleshooting rule is simple: if white ink repeatedly loses nozzles during printing, do not assume the printhead is the only problem.
Check the ink condition as well.
Solving the ink problem early can help prevent more serious printhead damage.