The UV LED printer head becomes one of the main problems for all the printer users while enjoying the benefits from the UV LED printing technology.

Why the UV LED printer head is more easily to be clogged or blocked? Start from the inside of the printer head itself (take Epson DX5 as an example). The golden surface has 8 chambers and each one contains 180 nozzles with about 1.5 nm diameter (1).

Clogging possibility No.1. The printer head has 8 ink damper holders, one holder for each color (2, 3). The damper is an important part to filter the inks from the ink tubes to the ink heads. The damper holder/filter can cause the clogging in the situation of:
1. Expired ink - when the ink inside the holder is bad quality or there is chemical change;
2. Long time without printing - the ink inside of the head is dry.

Solution:
Do not take the printer head out when the printer will not be used for less than 10 days, but use self-automated maintenance module from the control system.
Do not use the printer where the light is strong, especially direct sun light.

Clogging possibility No.2. Once the electronic part of the printer head is put aside (4), the manifold or adaptor will be exposed (5). Backside of the electronic print part, there is a channel for each color (6). Removing the rubber fixer as seen in the previous image, there are better displayed the eight holes where the ink will follow into the ink chambers are displayed better (7).

The next step is taking away the gold mirror panel from the back side of the electronic part which will allow seeing that the ink is staying in the plastic rubber container and then it is fired and shot out via the piezo vibration. There are 180 nozzles on each black column (8).
Notice: Even though the nozzles in the column are very small, the ink is hardly clogged here from drying or sedimentation if the ink is of good quality within shelf life.

The main reason for clogging is the Mirror Gold Metal Film! This gold mirror film (9) is the last point before the ink is printed out.

Due to the UV LED ink characteristics, the ink hardly dries or decants from inside. It is mainly clogged right at the surface of the mirror gold metal film. Why? One of the reasons is that during printing, the printer will create some powder due to the UV ink features and it will make the mirror side dirty. Another reason is represented by the printer head which is not wet enough and the ink inside will get dry to some degree.

To summarize, the printer head clogging happens for two main reasons:
1. Ink sedimentation which happens when the ink that is used has no quality or is expired and also when the printer is not in printing module, but it lacks on maintenance.
2. Ink drying which happens because of the improper maintenance that doesn’t follow the user manual request and also because of the long exposure of the printer in strong sun light environment.

The head clogging happens mainly because of the Mirror Golden Metal Film from outside to inside gradually. 85% of the printer head clogging is from this part and not any other part.

How to avoid the printer head clogging?
The ink sediments can be avoided by selecting quality inks and store them in the right environments. Also, activate the self-automated maintenance module if you are not going to use the printer. Moreover, change the consumables often (every 2 – 3 months) from ink bottles, ink dampers and wipers and cap top as well.

The ink drying can be avoided by operating the proper daily maintenance and cleaning the powder created from the printing to the Mirror Gold Metal Film. Avoid printer exposure under direct strong sun light environment and UV lighting resources as well.