MemberFebruary 13, 2020 at 3:23 pm
Our old JV3 is past it’s best so looking to replace with a newer JV33.
We can get a low mileage example that’s been running SB54 Dye-Sub – so we’d need to convert back to SS21 eco-sol.
I have been led to understand that this requires a LOT of flushing. Aqueous flush, water flush, solvent flush, solvent ink flush…and there is a 30% risk factor that the head may be blocked / damaged by doing this.
if anybody has any advice it’d be appreciated.
MemberFebruary 13, 2020 at 9:02 pm
i have never done this so take it a thinking out loud.
as its the head that would have the least amount of old ink in it i would consider flushing in 2 sections.
all to the dampers then new dampers then flush the head separate back together and fill. new cap and probably pump.
all presuming when it left the factory it was in solvent spec just dyesub ink used.
MemberFebruary 14, 2020 at 9:39 amquote Chris Wool:
That’s sort of what I suggested to the ink guy (QPS) after a discussion about the amount of fluid being used – to reduce the amount being pulled through the head from litres to ml.
Not that he was a doom merchant, just maybe excessively cautious…but does fly in the face of the seller…"easy, just flush them through. Not a big deal"
Machine has under 5000m2 on it, with a new head last year – so barely broken in. Could be a couple of grand if it screws up though for new head & install…hmmm.
MemberFebruary 14, 2020 at 10:22 pm
if its a dealer i would be tempted to say i will pay xx pounds for it with the conversion done and warranty as they say its not really a problem.
to my mind its the sort of job that you may do well to start with but 2 mts down the line the problems start, with all genuine parts and fitting could be nearer 3000
MemberFebruary 15, 2020 at 10:23 am
I would first conduct a simple experiment. Get some aqueous ink and try adding some solvent cleaning solution to see if anything coagulates that would cause a blockage in the head. Try the same thing with solvent ink this time adding water.if nothing coagulates out in either experiment then it should be a safe process. However if solids do appear in either case at least then you know which aspect of the flushing process is the most important, or you could abandon the idea altogether.
MemberApril 11, 2020 at 5:58 pm
Well…I did it.
Part on the advice of a bulk ink supplier (with a warning), part on intuition…and some button pushing to get the setting changed,
The general consensus is that it is NOT something that you can trust the machine’s own conversion / ink swap process to complete given the amount of ink mixing & dried deposits being dislodged so a lot of manual "lines off" pre-flushing in preparation for the machine to do it’s own party tricks.
(Technician mode and a couple of parameters need changed)
It’s a nerve-wracking process as you have ZERO idea that it’s worked or not until you run that first test print.
Had an entire black head missing…like gone.The rest 100% perfect…sound of "30% chance of destroying the head" ringing in my ears.
So soaked and reverse pulled the nozzle (air only) and flushed a few times with solvent through. Good spray pattern…back together, happy days.
Ran off a couple of prints today…a lot quieter and faster than the JV3.
Need to dial in the profiles for our media now but now a 2 machine shop again…until it’s time to fully retire the JV3.
MemberApril 11, 2020 at 9:51 pm
Happy Days David,
I tried this last month on a JV300 lots of advice from our technician and all sounded straightforward….. very nearly killed both heads – had to call in the cavalry to save the day [emoji15].
MemberApril 13, 2020 at 8:32 am
Yeh, not an easy process. Got to be fully committed to the possibility of effectively destroying the machine.
I couldn’t get a ‘pro’ to do it due to the risk factor – and no matter who I asked, they were VERY economical with the details they were willing to share making it sound a lot less involved than it really is.
eg. you still HAVE to go through the machine’s own internal ‘ink-swap’ process to get access to the solvent ink list…obviously I’d pre-flushed the lines with a bulk bottle (and head) to be solvent ready so just ran it all with solvent ink in a ‘fake it ’til you make it’…as I wasn’t dropping £300 on flush carts (that have no chips)…so if you pop of the ink chips from the carts – it’ll accept them as ‘flush’. 😉
Total of 2 litres of ink pulled through the system…’flushes’ and priming.
MemberApril 13, 2020 at 12:10 pm
I had a couple of lines where the sub and solvent ink had mixed forming a gel, so lucky that they didn’t get into the heads.
MemberApril 20, 2020 at 9:59 pm
MemberApril 21, 2020 at 11:53 am
well done love when a plan comes together
interesting operation changing a ink bottle ? just a thought its a lot a weight wobbling about on the cart frame.
whats your thoughts on the fact of a lot extra ink volume pressure on the dampers.
MemberApril 21, 2020 at 8:57 pmquote Chris Wool:
The bottles lock in and operate on a syphonic / atmospheric pressure arrangement not a simple gravity feed. Always remain at the same level. When fully empty, remove and pierce another onto the filler spike.
MemberSeptember 20, 2020 at 9:00 am
Update. Whether related to the swap or not…we required a full head replacement a month back.
Engineer remarked that he’d never seen a head fail so spectacularly internally.
Back to a brand new condition…some ink pressure / flow issues but altered the static head of ink to compensate.
MemberSeptember 20, 2020 at 11:17 am
we run the exact same bulk ink system never had a problem best change we ever did
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