Yard signs sticking together

[Signed Out]

The last few batches of yard signs that we have done have been sticking together. This hasn't happened before that I know of. We print on oracal 3641 on a roland xj 540, oem inks. We print yard signs with gcvp profile in standard mode with the take up reel, let dry on a roll for a day before we mount and cut. A few weeks ago we had a customers signs in our shop for a few days and I went to move them and they all stuck to eachother. When I seperated them they had transfered ink from one another and looked like crap. Not sure why this is happening. Since we have tried letting the prints dry for 4 days before mounting and it still happens. Also tried printing in high quality print mode, didn't make a difference. It has been hot and humid around here lately but our shop is climate controlled so that shouldnt make a difference.

We're printing some samples with different profiles, heat settings, dry times, etc. to see if we can figure it out. Has anybody else had this issure? Is it just not kosher for unlaminated digital prints to touch eachother? Could use the backing paper as a barrier but that would be annoying for me and the customer. Was also thinking possibly a silcone spray lubricant might work...probably not. Would much rather figure a way to print them so they don't stick.

 

[Banners Signs Etc.]

We either stand them up so they aren't sitting on top of each other...or print on matte material...doesn't stick when "dry", except to bare aluminum.

Its really the weight of them pressing together that transfers the ink...but like you said if its really a problem use the backing paper

 

[Gino]

Dust 'em with baby powder before you stack them.

 

[Banners Signs Etc.]

Dust 'em with baby powder before you stack them.

Nice!

 

[Signed Out]

We've tried standing them up also and still seems to happen just not as fast. That is good to know about matte not sticking to eachother, I'll have to test that out, but doesn't help for signs that need to be glossy. Is dusting with baby powder common practice? what if the signs were out for a day or two, maybe it rained, then stacked by the customer and they stick to eachother? from the responses so far it seems that I probably wont be able to remedy the problem with different print settings/conditions... which is disapointing.

 

[thinksigns]

We started on 3641 and were having the same problems. Switched to 3164 matte and haven't looked back.

 

[Gino]

The powder will last a short time. It's not a cure-all.

Technically, your signs haven't cured. In other words, no matter what your heat settings are, the matte or glossy finish or anything else is.... the solvents have not yet dried.





Ever take a shower and completely dry off and you still feel clammy ?? Samating.


Until the carrier is completely gone... you're gonna stick. Need to be completely dried.

Cured is just another fancy word for thoroughly dry, unless you're talking about meats.

Dry to touch is all your settings are going to do, while cured means the solvents have completely passed out. Now it is 100% dry. That can take as much as 3 months in some instances.

Where was that vinyl before it came to you ?? In a hot humid truck being delivered... for how many days ?? How long does it take to get all of that extra moisture out of there, until you plaster it with ink and it now has moisture trapped under the ink ?? Oh yeah..... that might have something to do with it.

 

[Signed Out]

Does the 3164's clear adhesive allow sunlight to pass through, making the signs hard to read on a sunny day?

 

[TheSnowman]

I've been using 3621 Matte and that stuff is awesome. You can lay down prints right away because it doesn't curl like the gloss always did for me. I haven't had any issues with ANYTHING sticking with that. Heck, I can't hardly move it with my hands because they just slide right across it instead of being able to grab from the top easily.

 

[Signed Out]

Thanks for the breakdown Gino. 3 months is a long time to wait for yard signs. Out of curiosity how long do screen prints or uv flatbed prints take to fully cure?

 

[Banners Signs Etc.]

what if the signs were out for a day or two, maybe it rained, then stacked by the customer and they stick to eachother? from the responses so far it seems that I probably wont be able to remedy the problem with different print settings/conditions... which is disapointing.

Yea its not your print settings...if they get rain on them they are probably less likely to stick because of all the pollution/pollen coming down on them...baby powder principle...maybe should let all our signs get rained on...mother natures laminate certainly protects my car

 

[d fleming]

Screen printed coro using corogloss ink and fast thinner- can print second side in about 30-45 minutes, let sit on rack overnight before stacking. The problem of printed material sticking together from being stacked before cure is commonly called blocking. I always stack and box coro standing up rather than laying flat as an extra precaution. The weight of a stack of 100 coros is pretty significant to the bottom coro.

Thanks for the breakdown Gino. 3 months is a long time to wait for yard signs. Out of curiosity how long do screen prints or uv flatbed prints take to fully cure?

 

[Sign-Man Signs]

We laminate ours. Just saying.

 

[Gino]

Thanks for the breakdown Gino. 3 months is a long time to wait for yard signs. Out of curiosity how long do screen prints or uv flatbed prints take to fully cure?

Didn't say you had to wait 3 months... that's how long the process could take. We send signs out in less than 24 hours of being printed.

Generally, screen printed flat stock is ready within an hour or so, we have fans blowing across them while we stack them up. Some are dried within 10 minutes.

U/V signs are dried within about one minute to about 99% dried and cured. Sometimes we experience some sticking, but that's if we stack large very heavy items on top of each other. Most of our jobs are printed and stacked after removing from the bed. We did a job a few months ago on 60" x 152" aluminum composite. 22 pieces. After printing one, we would let it stand free for an hour before stacking another piece on top. Til we were finished, that would've been a lot of pressure for any printing method, so we stood them on end out in the garage for the rest of the day.

In any case, when stacking ink to ink.... you always have to be careful. I don't think there's any one safe way to consider to be the best way.

 

[Banners Signs Etc.]

you could build a drying rack out of those metal closet racks if you intend to let em sit

 

[Signed Out]

Thanks for all the responses guys. Going to pick up a roll of 3621 matte and try that out. Still have 50 signs worth of vinyl already printed on 3641g and has been drying for a couple of days, think I'll try the baby powder method for those.

 

[LittleSnakey]

If your using flexi for your rip you can try high speed setting for quality, this will reduce the amount of ink and print faster.

 

[eahicks]

Pretty common problem...we just slip the vinyl backer pieces in between them.

 

[TheSnowman]

You'll love the 3621 Matte. Economical price, and it works great for temp yard sign stuff.

 

[john1]

Pretty common problem...we just slip the vinyl backer pieces in between them.

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