Mimaki JV33 dye sublimation print head failure

[richardc74]

Hi,

We have a strange reoccurring issue on both of our Mimaki JV33/160 dye sublimation printers which I like to understand if anyone has encountered. The issue occurs across both machines sporadically so I am not sure if it is environmental or paper/ink related.

We install a new print head and the printer is fine for a period. The printer then starts to drop nozzles and the first sign that the head is not working correctly is we will get contamination between the yellow and black left channels. Sometimes black will start to appear on the yellow channel nozzles at the back or the front of the head (never in the middle). Alternatively we can also get the head missing a lot of nozzles on these two channels (see attached image of test draw). When we get a technician in to look at the issue they tell us that the chambers between the channels have ruptured and ink is leaking between them. To show us the issue they will either push ink into the head by pressing the damper down or they will use a syringe and tube to push ink through the head. Ink then appears to come out of the side of the head where the face plate attaches to the print head. We had this same issue last week on a print head that was installed in late April so the head is no more than 3 months old. We have tried both Mimaki original and OEM heads and doesn't make any difference.

Any assistance would be greatly appreciated as I can't keep buying new heads every couple of months.

 

[CA Creative Group]

Can you provide info on your ink setup whether its regular carts or are you using bulk ink system?

I own a jv33 160 bought it early 2020 in pieces with only the base machine without the dampers, memory chip, print head etc. so to say I've had to learn a lot about this machine in order to get it working again and I've personally experienced many issues while troubleshooting it during the rebuild process.

The reason you are getting blow-bu when the tech bleeds it with the syringe is due to them putting to much pressure on the print head forcing to much ink through too fast. I experienced the same ink blow-by across channels when I manually purged my print head with a syringe when I was trying to troubleshoot dropped out colors like yours.

If you're using a bulk ink system the pressure on the system could be increasing due to temperature or possibly the height of the bulk ink system or combination of both. The reason for the dropout on the yellow could be due to air getting in between the print head and the valve top from the pressure

I think it would be unlikely that your printheads on both your JV33's are going bad in 3 months but that depends on how much ink you are going through in 3 months. If you're using bulk you can try lowering the ink bags or switching to 440ml carts to see if the issues resolves.

I run 8 440ml carts and I am almost done my 2nd set of carts since I first bought my machine and a new printhead and knock on wood I've been running with no issues for a few months now.

 

[hybriddesign]

Hi, I'm guessing this isn't it as it's pretty obvious but have you had any nasty head strikes. We had this happen once where the retainer (for lack of better words) that runs around the edge of the head got kind of peeled back during a head strike and we then had ink leak out of the side. Being that you're on a sublimation printer I doubt that's it as paper doesn't usually jam badly enough to cause this.

It does look like your head is bad and you're getting cross contamination as you noted. I've killed heads quickly like that too and just got rid of our JV300 as we kept having similar issues. One head would last forever and then a brand new oem head would die in a couple of months... so weird.

You could also have ink pooled down by where the nipples go into the dampers and if you have a cracked nipple you can get contamination there.

Anyways, guessing you need a new head but maybe someone else can help to figure out why.

 

[Dangreenst]

Hi,

We have a strange reoccurring issue on both of our Mimaki JV33/160 dye sublimation printers which I like to understand if anyone has encountered. The issue occurs across both machines sporadically so I am not sure if it is environmental or paper/ink related.

We install a new print head and the printer is fine for a period. The printer then starts to drop nozzles and the first sign that the head is not working correctly is we will get contamination between the yellow and black left channels. Sometimes black will start to appear on the yellow channel nozzles at the back or the front of the head (never in the middle). Alternatively we can also get the head missing a lot of nozzles on these two channels (see attached image of test draw). When we get a technician in to look at the issue they tell us that the chambers between the channels have ruptured and ink is leaking between them. To show us the issue they will either push ink into the head by pressing the damper down or they will use a syringe and tube to push ink through the head. Ink then appears to come out of the side of the head where the face plate attaches to the print head. We had this same issue last week on a print head that was installed in late April so the head is no more than 3 months old. We have tried both Mimaki original and OEM heads and doesn't make any difference.

Any assistance would be greatly appreciated as I can't keep buying new heads every couple of months.

I have found several dye sub inks to be very harsh on plastics and rubber parts like caps wipers and dampers. Any deterioration of these items and lead to failures or cleaning issues. If new items continue to fail, you may want to consider changing inks.

 

[richardc74]

Can you provide info on your ink setup whether its regular carts or are you using bulk ink system?

I own a jv33 160 bought it early 2020 in pieces with only the base machine without the dampers, memory chip, print head etc. so to say I've had to learn a lot about this machine in order to get it working again and I've personally experienced many issues while troubleshooting it during the rebuild process.

The reason you are getting blow-bu when the tech bleeds it with the syringe is due to them putting to much pressure on the print head forcing to much ink through too fast. I experienced the same ink blow-by across channels when I manually purged my print head with a syringe when I was trying to troubleshoot dropped out colors like yours.

If you're using a bulk ink system the pressure on the system could be increasing due to temperature or possibly the height of the bulk ink system or combination of both. The reason for the dropout on the yellow could be due to air getting in between the print head and the valve top from the pressure

I think it would be unlikely that your printheads on both your JV33's are going bad in 3 months but that depends on how much ink you are going through in 3 months. If you're using bulk you can try lowering the ink bags or switching to 440ml carts to see if the issues resolves.

I run 8 440ml carts and I am almost done my 2nd set of carts since I first bought my machine and a new printhead and knock on wood I've been running with no issues for a few months now.

Hi,

We have a 4 bottle bulk loading system on each of the machines which were installed from new. We only half fill the bottles and never close the lids completely. The printers run pretty much 8 hours a day 5 days a week so they do work quite hard.

 

[Solventinkjet]

Dye sub inks blow heads much faster than solvent. 3 months is still a very short time for them to fail though. What ink brand are you using?

Your tech is correct that if you flush solution through one channel and it comes out the other, the membrane is broken. That could be from the ink damaging the head over time, a bad head strike, or flushing the head too hard. If the exact same thing is happening on other heads with the same ink, I would suspect the ink. There was a dye sub ink company last year that had a bad batch and we were selling heads into those machines like crazy. Some people were only getting 3 months just like you which is why I ask which ink brand.

Are you changing the dampers out with the new heads?

 

[premiercolour]

We are an authorized Mimaki dealer servicing S. California if you are in the area please give us a call.

I agree:

The reason you are getting blow-bu when the tech bleeds it with the syringe is due to them putting to much pressure on the print head forcing to much ink through too fast. I experienced the same ink blow-by across channels when I manually purged my print head with a syringe when I was trying to troubleshoot dropped out colors like yours.

 

[richardc74]

Dye sub inks blow heads much faster than solvent. 3 months is still a very short time for them to fail though. What ink brand are you using?

Your tech is correct that if you flush solution through one channel and it comes out the other, the membrane is broken. That could be from the ink damaging the head over time, a bad head strike, or flushing the head too hard. If the exact same thing is happening on other heads with the same ink, I would suspect the ink. There was a dye sub ink company last year that had a bad batch and we were selling heads into those machines like crazy. Some people were only getting 3 months just like you which is why I ask which ink brand.

Are you changing the dampers out with the new heads?

Hi, We were using Sensient inks and then last year changed to a new brand called Print Rite. We experienced the issue on both ink types so I am not sure it is the inks. We don't always change the dampers when we put a new head in.