Mimaki CJV150 Cross Contamination Help

[Mathew Atkin]

To cut a long story short our cjv150 was dripping ink onto the media last week. We replaced the dampers and capot and the problem was resolved. This week we now have cross contamination in the yellow channel. This is present as soon as we turn the machine on after it has been left overnight and soon clears up after running a few nozzle tests. I have checked the cap position to ensure it is not that and swapped the cartridges to full ones and the issue is still happening. Could this possibly be a faulty damper again? We used genuine ones and are worried that the head might be on its way out.

I have attached a photo to show the progression of colour after a few nozzle tests. We pulled the damper out and there was defiantly black ink mixed in with the yellow on the circular section where the button is.

Any help will be much appreciated.

 

[Solventinkjet]

The fact that it recovers fairly easily and stays that way while printing means it's more likely an ink flow issue. Did you change all of the dampers or just the problem ones? If you only changed one, that could be the issue. Sometimes when you have a strong new damper and a weak old damper it causes pressure issues and can cause contamination. If you changed all of the dampers, check the lines for any air bubbles. That could be a sign there is a bad seal somewhere causing flow issues as well. If that's all good, make sure your waste tubes aren't fully or partially clogged.

 

[Mathew Atkin]

The fact that it recovers fairly easily and stays that way while printing means it's more likely an ink flow issue. Did you change all of the dampers or just the problem ones? If you only changed one, that could be the issue. Sometimes when you have a strong new damper and a weak old damper it causes pressure issues and can cause contamination. If you changed all of the dampers, check the lines for any air bubbles. That could be a sign there is a bad seal somewhere causing flow issues as well. If that's all good, make sure your waste tubes aren't fully or partially clogged.

We replaced all 4 of them at the same time. I suppose it could still be a random faulty one from new though. I will check down the lines to see if there is any air. If there is air could this have been introduced since changing the dampers? Also if it was a seal would you see any signs of ink leaking around the areas where joins are?

 

[Solventinkjet]

We replaced all 4 of them at the same time. I suppose it could still be a random faulty one from new though. I will check down the lines to see if there is any air. If there is air could this have been introduced since changing the dampers? Also if it was a seal would you see any signs of ink leaking around the areas where joins are?

Any air that gets into the system eventually get's pulled out during cleanings if all the seals are good. Air bubbles in the system that do not get pulled out usually indicate an on going leak. Ink rarely drips out when there is a seal break. Instead air gets sucked into the system. If the leak is bad enough, it will make the ink recede all the way back to the cartridge filling the line with air. When it's a small leak, you just get air bubbles and ink flow issues.