Black ink sticking to vinyl on take up reel

Probably a combination of several things:

Too much ink: Black isn't just K, it is a combination of CMY and K. If your profiles ink limits are too high you could technically print 100% of each ink. Most stock profiles will limit it in the 280% range. A good all-around Black is 60C 30Y 60M 100K which is 250%. You can lower it even more by dropping the Y to zero but in some light, you get a purple cast to the black.

Printing too fast: The faster you print (fewer passes) the quicker it puts down the ink, and the less time it has on the print and post heater to dry. Try upping your passes to give it more time to dry. If I remember correctly you can also add a delay to the end of each pass which will also give it more time to gas out.

Need a better drying system: You say you need the speed, buy an additional heater. In the past, I have worked with the Benes dryers and loved them. Roland sells them but you can get them elsewhere. There is also a rollup UV heater with fans.

I never like the print, direct to cut feature. The ink makes the vinyl gummy and difficult to cut well. Even if you add a white border the pinch rollers tend to add a nice feature to your graphics.

 

what are the ink values of the black? is it super rich black - like C100-M100-Y100-K100? I hate it when people build art like that. way too much ink.

 

Yep, as above.. ink loading is too high to dry before it rolls back on itself.
Try pointing a fan or two at the prints as they come off the printer. This might buy you enough dry time.
We built our own dryer fan unit as we were experiencing the same issues when printing 6 pass or faster which resolved the issue permanently.

 

Maybe try using spot black from the roland color library. BK21a is 100% K and bk22a is composite. I get some markings on the beginning of the take-up with blacks but not through the whole thing. I think this would indicate that tension/pressure could have something to do with it also.

 

Fans kick up dust.
Heavy black mix, 4 pass and straight to cut from print? I'm no expert but I'd venture to say, there's your problem.

 

When we used solvents we used to point the fan directly at the media from the front... The air circulation over the ink dries it. It also keeps a constant airflow and prevents any dust from sticking to it since it just blows it away. You should be fine pointing a block fan at it for testing.

Big heaters aren't bad, but once summer comes you'll regret having one.... Though maybe it'll be warm enough in the summer that it dries OK without it.

 

Just so you know, the ink can't really outgas on the takeup real. The solvents just soak into the vinyl, adhesive, and liner. If You're waiting 60 min, why not take it off, unroll it, and let it dry properly overnight. The vinyl will be less gummy, cut and weed better the next day, and you will have a lot less shrinkage and edge curl.

 

Yeah totally agree here - we tend to let almost all our cut graphics outgas at least 12, preferably 24 hours, sometimes over a weekend with some media (looking at you, Avery 2611) or we risk that dreaded edge-curl. Especially with a black.

It's too bad this model doesn't have a platen on the front, does it? I guess you could let up on the black and just do 100K but... ew. I feel like this is one of those situations that you can have it fast or you can have it good

 

100K isn't a very rich black. Try 30 30 10 100 and up the passes to 16 and you won't have any problems. If your waiting 60 before it cuts, what does it matter how long it takes to print? By going from 4 to 16 passes you get crisper prints and it will be on the heaters 4 times longer. If time is an issue, back of the delay before you cut. Its not drying on the take-up real anyway...

 

16 pass isnt necessary IMO, try upping it to 8. I always use the take-up and the ink dries, it's not air tight. I think you're going to get curling no matter how long you wait to cut if it's full bleed but laminating will help stop that. As far as black, 100% k always looked good to me.

 

16 passes will lay the ink down in smaller more precise droplets (1200 dpi). Laying 1/16 of the ink total on each pass. Some profiles will add a small percentage more ink but you have considerably more drying time. A 4 pass print lays 25% ink on each pass, flooding the vinyl with solvents and spending a 1/4 of the time on the heaters. If you are running four passes you don't have to go directly to 16, try 8. I used to print all our vehicle wraps on 8 passes on a SolJet 540V Pro II without any problems but we had the Digi dryer.

One of the benefits of a higher pass count is that your ink is less likely to pool and get an orange peel look. Sometimes solid browns, hunter greens, and maroons will look mottled when you print at lower passes, most noticeable on banner material. I've seen this referred to as dot gain where the colors bleed together. The net benefit of a high pass count is that your details will be crisper, less pixilated looking, the text will be sharper as well. Lighter tones and gradients will look better as well because the printer is using many smaller droplets to make the same color density instead of one big one. Also, banding is less noticeable, especially when you have a few missing nozzles at higher pass counts. Typically the lowest pass count is called billboard or draft mode and the highest pass is high quality for a reason.

If your adamant about using a lower pass count you can also switch from a bi-direction print to uni-directional. This only prints in one direction and doubles your drying time. And, you can add a delay or dwell time to the end of each pass as well.

As I said before, there are 3 ways to solve your problem. Slow the print down, add more heat post-print, or use less ink. The first cost time, the second money, the third will affect the richness of the colors you can print. You can choose one or two of them or balance all three.

If it were me, I would print on 8 passes with crop marks in the afternoon. At the end of printing the day's graphics, I would take them off the takeup and stand them on end in a milk crate loosely wound (you can leave them on the core). After drying overnight, I would put them back in to cut without the heaters turned on and cut them all. You can process the cut prints as each batch finishes. When your done cutting, turn the heaters on and start printing again and finish processing the cut graphics. I never like cutting with heaters on.

Things go wrong so you will have times when you will have to print and direct cut so you still will need to solve your drying problem. There's nothing worse than having a problem when a deadline is looming.

I would suggest you take a sample of the problem file and print it on every pass count and compare the difference. Touch each one right after they print, and look at the difference in quality. No better way to learn.

 

That's retarded.

 

I don't know your situation and work flow but for most shops, I think you went a little over the top. Remember there will be many times when a deadline won't allow you to run that slow. I would find a good balance trying to maximizing your efficiency and take into account growth.