JV33 - Heat Problem?

is it set too high so that it will warp the vinyl?

 

Hi
not from your part of the world, but is the material being stored in humid conditions. If it is the backing soaks up the moisture so that when its put in the printer the heaters dry the moisture out causing the material to buckle. Just a thought as i said not from your neck of the woods

Kev

 

I had the exact same problem. Mimaki recommends 40/40/50 for heat with the ecosols. Less than that (~35/35/50) with the SS21's. Check your manual and you'll find the recommended settings for different media types.

I run 45/45/50 for 13oz double sided banner no problem, but once I got into the thinner adhesives it was starting to buckle really bad. The faster the machine was printing the worse it got. Seems like the backing and vinyl are expanding at different rates.

Then I started using the take-up reel and that problem went away. Keep some old vinyl and an old core and tape it to the media as it comes off the print platen and use the take up reel. It's a pain in the butt, but it's less of hassle and cheaper than reprints. No need to pull your virgin media down to the take up reel. Juts use a leader. I haven't had a streak/strike since.

 

What's a leader? just using old vinyl?

 

My JV-33 is set at 50-40-50 and I have never had a problem and never changed the setting.

Kevin

 

When we first got ours, we had problems with head strikes. After messing around with temperatures and a few other things, we finally raised the head height. There is basically no difference in quality, and it has eliminated head strikes.

 

Yes.

 

Try the Avery profile MPI 1005V3
PRE 29
PRINT 33
POST 50

 

i dont know about on jv4's, but on our jv 3's and 33's there are two little screws on the front of the carriage, if you tighten them up it raise's the head higher off the paper. you get better quality from having carriage set to thin, but you also run a higher risk of head strikes and messing up your heads. We have all of our carriages set to thick at the moment, and have for as long as I can remember. There is also some kind of set-up you have to do threw the configuration tree on the panel on the mimaki, but all of that was already set when I started working here a few years ago. It just lines the print heads up correctly so they adjust for the difference in the gaps.

The carriages HAVE been known to, over time, start to droop a little and start causing head strikes in dang near everything we do. Either the screws will become loose from being in near constant motion, or the belt that the carriage moves on starts to get a little worn out and start sagging. I'm not sure how to tighten up the belt, but I know that in 8 years of printing with our JV3's we have never had to actually REPLACE the belt.

To see if your head is sagging too much, just watch it go back and fourth as it prints, if it looks too close to the paper, or if it is clipping the little metal sliders that hold the paper in place, you need to make it a little higher.

 

WOW, you guys really run at that high heat? How many pass?

I run my post heater at 50c and leave the others off. The radiant heat from the post heater tends to keep the print at about 32c and the pre around 28c. No curling, and no head strikes (unless you have the head to low).

When we are doing big banner runs we'll turn it up 30pre 35print and 50 post and raise the head up a bit so we have no hits.


If you have your print set at 40c for vinyl your going to bake the ink before it even has a chance to setup properly with the subesquent passes of ink that are going to lay down. This is what I've been told my multiple techs including the guys down at head office if Miamki.

Keep in mind - when your adjusting the head height you should always be recalibrating in the "drop position" menu. I think its somewhere in the maint. 1 sub menu if I recall.

 

My ink limit tests show I can lay down more ink and increase the color gamut with the higher heat settings. Of course I'm using the ES3 inks which don't have as aggressive a solvent as the SS21's so the higher heat settings are a necessary evil. The mild solvents definitely dry faster and don't require the same amount of heat to set-up. When I run the machine on 6 or 8 pass without the higher heat it will offset the print on the back of the media when using the take up reel. 12 passes or more seem to give it enough dry time, but just barely at 540 x 1080. Canned profiles are generally pretty conservative on ink usage. I roll my own and push the limits of each media to maximize colour.

I've found not all medias are the same. The cheap stuff will buckle all the time, but I run 3M 180CV2 or Arlon 6000X through @ 40/40/50 with zero issues. Same with banner vinyls, photo papers, canvas, etc. It's just the el cheapo adhesive stuff that ever causes a problem.