printing over night mimaki jv33?

[DCSMITH]

does anyone print over night with no one to watch the machine and is there a way to prevent over night banding? we print 24 hours a day 7 days a week and it seems to be a 50 50 chance on banding with my experience. I think it would save more money and product to have someone watch it over night any thoughts or suggestions would be appreciated.

 

[SightLine]

If it starts banding then you need to determine what is wrong. My suspicion would be ink flow related if it can start banding in the middle of running. If it were media feed related then it would be banding as soone as you start printing.

That being said - we run ours overnight all the time without any issues. Just be certain you have enough media on the roll for the job as well as enough ink in the machine. Get it started, tape it onto a tube on the takeup and let it go. Depending on the job we will often put a new full roll on and print the entire roll overnight.

 

[DCSMITH]

it is definitely ink flow related but i changed the pump capping station and all 8 dampers and ive used the same ink forever now the only thing i can think of is maybe its the batch of ink i got so i asked for a different batch number on this order do you think that would change anything?

 

[DCSMITH]

and the machine is basically brand new not even a year old yet and i run the same ink on my other jv33 they are both ran on bulk ink systems but one with cartridges one without the one without is the one thats giving me problems i dont know if that would change anything either and there is no air in the lines

 

[DCSMITH]

and its not the feed compensation it prints very well until i run it over night when i come in the morning i do an ink fill and a soft clean and the banding is fixed

 

[TheSnowman]

You are preaching to the choir on this one. Had it on my JV3, so I got me a JV33, and now anything past a couple feet that's solid ink, it's starving it. Get's really bad banding. Wish I had the solution. Buying a latex is my solution I guess cause I'm not getting anywhere with the current setup.

 

[SightLine]

If it is an open tank style bulk ink system then that is most likely the problem. In my experience on a JV33, any bulk system that has refillable tanks, floats, refillable cartridges, etc IS the air leak and will ultimately cause problems. With the valved ink train and spring loaded dampers the ink train on these, the ink system is very highly tuned to very specific pressures. I've explained it before in prior posts regarding this. The only bulk systems that are truly going to give the least problems are those that are sealed systems using ink bags. What is in a regular cartridge? An ink bag. As ink is used what happens? The bag collapses and pressures in the system remain constant. On a hard tank leading to cartridges with floats or whatever what happens as ink is used? Either the cartridge has to collapse, or a float has to drop some to allow more ink to flow ink, beyond that point something is still opening and changing the pressures. Something has to either collapse or be vented to allow air to displace the ink that was used. With sealed bag type bulk systems like Mimaki's own bulk system, MBIS or Triangles EcoBulk, Bordeaux's BBIS, and a few other brands that have ink bag based bulk systems out now all keep pressures in the ink train just as if it were using cartridges. On the bag type bulk systems the bag simply collapses just as if it were a cartridge. Most also still do offer the older style open tank type bulk systems but they are just not going to work perfect all the time on a JV33. That style did work well on the older JV3 though which was a gravity based ink system. With a bag type bulk ink system the bags collapse as ink is used just like cartridges.

If however it is a bag type bulk system then its hard telling for sure without really being in front of the machine and going over everything with a fine tooth comb.

 

[DCSMITH]

my ink system is gravity based but not with bags its it with 2 liter bottles that run straight to the dampers no cartridges

 

[Robert M]

Gravity

Try increasing the height of the bottles. This will increase the pressure on the ink in the lines. If you go too high ink will start to drip from the heads. Make sure your dampers have clean screens also.

 

[Jack Knight1979]

I had the same problem with direct bottle feed systems. Never worked for me. Since I switched to the float style system I have had no problems. Printing over night. No problem.

Keep extra carts around. The valves go bad over time.

These systems are not as reliable as a vacuum bag, but the plus is you can top of tanks before a long print run. Which you can't do with bags.

 

[DCSMITH]

yeah on my second jv33 i have the float style system but when i got the second one the tech who set it up insisted on the direct bottle feed system. when changing the systems is there anything i would need to do besides putting the carts in and running the lines?