Ink flow in Printhead – How Inking System Works (Part 3)

Ink flow in Printhead – How Inking System Works (Part 3)

This is an article put together to show the client at home how our inking system works. It also gives you some guideline of daily maintenance and troubleshooting.

No matter what kind of printer you bought from us, the principle of ink delivery is the same. In this video, I will explain to you how the inking system works in general and give you some guidelines of daily maintenance and troubleshooting.


If Colours get mixed in the Damper

If the ink flows back (also known as the ink backflow) and is mixed in the damper meaning that the ink in the damper is not in it’s original colour anymore. In some cases, you may even see the ink backflow when it travels through the tube back into the ink tank and tamilate the whole tank of ink. The printhead cannot suck ink inside, the real reason is the pressure of ink in different ink tank is different because the level of the ink is different, which means some ink level is higher than the other one, so the gravity want to balance the ink level and the high level ink go into the lower level ink damper through the printhead.

This process is very slow, so you are more likely to see after didn’t use the printer in a while. And also, most printheads, when it has power, will slow or stop the ink flow.

To get ink in damper back to original colour, just use cleaning function, the ink pump will pull all mixed ink out until the fresh ink from ink tank refill the damper again. If the ink tank has been terminated with wrong colour ink, you have to throw away the ink and flush it with cleaning liquid, then put new ink in. Once you have new ink in the tank, use the cleaning function to get the new ink into the damper.

Since the colour mix is caused by ink level, you can simply solve this issue from happening by refill the ink to the tank and make them same level, generally 80% full is fine. And also you don’t need to do this all the time, just balance the ink level before the end of the day is fine, besides refill the ink when ink level goes low when printing.

If there is Ink dripping from the Printhead or any that will not go into the Printhead

The inking system is a pressure like process whereby, ink is fed into the damper and then into the printhead. This is because when the printhead squeezed the ink out, a vacuum space has been created which creates a negative pressure and the ink flows and fills up the space because the atmosphere pushes on it. That’s why we call it negative pressure, it’s a comparison to the atmospheric pressure.

If your ink level is very high (like almost full), and you also in a near sea level area which means atmosphere pressure is higher than any other placed, the ink may start to drip from the printhead and you will see excess ink when printing because of this phenomenon, or you what you need to do is to not put too much ink in the ink tank at the back.

This is also often seen on modified ink tank when the client wants to use a bigger ink tank, which can store more inks and need refilled in a short period of time, and without much option, place the bigger ink tank on top of the machine. This has become a common option. It will create a much higher pressure because of gravity. As you may have noticed, no matter the shape of our printers, the printhead are always at a similar level of ink tanks. When you place the ink tank higher, the extra pressure caused by gravity will push the ink out of the printhead and those tiny droplets will start to form and either terminate your print or make the whole printer unusable.

On the other hand, sometimes we cannot get ink into the damper, even we pull it by syringe. In some simple cases, the reason for this is because the cap for the ink tank is too tight. When you make the feeding side of the ink airtight, then there is no pressure from atmosphere so ink won’t come out. This may also not be the case because we normally get ink tube from a hole into the ink tank, and the hole is always bigger than the tube which will let the air in. Sometimes we do not notice that some of our clients block it by sealing it with Prestik because air will terminate the ink and cause ink dry. Initially, the vapor from the ink fills the empty tanks which usually protects the ink, the gap between the tube nearby the edge of the hole are usually small, there won’t be any flow of air to exchange vapor with air, so that ink does not dry because of the little gap. The  cap also has to be tightened.We normally suggest that you screw the cap to close to the position and unscrew it about roundabout half circle to make some space to let the ink tank link with the atmosphere.

Of course, the contamination, dried ink etc may also block the tube and cause ink to not flow or flow very slow and eventually cause ink feeding issue, and this can be easy to figure out when you use a syringe to pull.

About Advanced Machinery (Pty) Ltd:

Advanced Machinery (Pty) Ltd has been operational in South Africa since 2013. Their main warehouse is located in the heart of Jet Park in Boksburg. They stock and sell a large variety of printing and cutting machinery ranging from Vinyl cutters, Laser cutters, Plasma cutters, CNC routers, Large format printers and so much more.