UV Prints viability in extreme cold

[NatGraph]

Background:​

-My company exclusively designs and manufactures signage for high-end multi-family new construction projects.
-I guess you can say our "thing" is using stone in a lot of our projects.
-We've been working with an Epson SureColor V7000 for a bit less than two years. Don't love it, don't hate it.
-We are in Texas, where it never gets cold and when it does we don't know how to properly function.
-Our customer base is mainly in The South, but we occasionally do get some projects in the New England area.

Probem:​

We recently received these pictures from our (largest and most important) customer who we did an install for in Massachusetts within the last couple months. At first glance I said, "Oh that isn't even printed" because of how wild the failure is. I've never seen anything like it.
It seems to have happened right after a sever cold snap. (Not even sure what to call it when it gets cold super quickly) We had no way of predicting or testing this.
Going forward we need to replace these pieces, of course, but don't want to use the same process for it to fail yet again.

Question:​

Does anyone have any experience with UV prints in the cold weather?
Does anyone else print on stone?
Can anyone provide some tips for better adhesion?
We are also open to using any other techniques that will yield a resilient and attractive product.

 

[DarkerKat]

That's wild, I've only seen this kind of failure on heavily-layered prints.
What kind of stone? If it is raw stone then I guess it would make sense that water could get into the pores and expand when the temperature drops.
Did these signs have white ink under the color?

Not saying this to knock your product, but when I first looked at the photos they just looked like a frosted white acrylic - that might be a safer material to use for exterior signs in extreme environments when you replace these. It will still expand and contract with the temperature but it shouldn't absorb moisture in the same way.

 

[NatGraph]

Yeah it is a raw stone. I guess water can get behind the print and expand?

High-end customers tend to want the more expensive materials without regard if it looks like something you can make for much cheaper. We are exploring other options, but they wont like "let's replace it with plastic".

 

[DL Signs]

Weather in the northern states swing from 90's in the summer to negative 30-40 pretty regular in the winter, wind chills usually dip to around negative 60 a few times every winter in many areas. We get ice storms, rain that saturates everything porous, then massive temperature plunges that flash freeze everything, then the sun hits it and... It's hard on signs and graphics here in the north.

One thing with direct UV printing is the shrinking and expansion with massive temp changes. If it isn't on a good substrate with excellent adhesion it can crack, and flake as it expands and contracts. Flexible UV inks help, but not always 100%. What yours looks like is the stone may have absorbed moisture, it got behind the ink, froze and just pushed the ink right off. Porous substrates are not ideal for exterior direct printed media in freezing northern climates.

For stone I'd seal it first to make sure no moisture can get behind the ink. I'd use the flexible inks to handle the shrinking and expansion, and maybe even run a sealer or clear coat over it to seal it down. One thing I wouldn't do up here in the north is guarantee any specialty thing like that, at least not until you find a method that works with what you have to work with. You can somewhat test it yourself, print, bring it in and out of a freezer, do it like the conditions we have, hot/ cold/ wet/ dry/ all in random order. Bet if you print a piece of that stone, soak it in water for a while and pop it in the freezer till it's frozen solid, then throw it in the sun you'll replicate it. Sounds harsh, but that's what winters are here. Now, remind me again why I live up here???

 

[Andrew Heiner]

Engrave / fill is a better option.

 

[A Signage]

We're just 20 minutes north of Boston and we had the same thing happen last winter to direct UV printed acrylic panels.
It was during the cold winter months, all the letters just fell off, the remainder could be touched and just flake off the rest of the way.
We were able to just plastic razor the remaining letters off and replace with HP vinyl, problem solved.

 

[Gino]

There're several things this could be, but first, you need to explain your process.
What is the bluish back piece and what did you do to it ?? What is the white pice and how is that mounted ?? Next, what kinda vinyl lettering did you use and did you use any liquid agents to help put it all down. Lastly, how did you mount the entire project to the walls

 

[CanuckSigns]

If price is not a concern, i would look into using corian instead of stone, it still looks like stone, has a 50 year outdoor lifespan, and you can engrave and paint fill it, it will outlast the building.

 

[Souldar]

did you use adhesion promoter?

 

[Ewan yu]

There is a UV flexible ink that can withstand temperatures as low as -18°F

 

[Ewan yu]

There is a UV flexible ink that can withstand temperatures as low as -18°F

However, it seems that the printhead on this printer does not support this ink.

 

[Stacey K]

For the fire pit: A wild idea...is this close to the fire pit? My first question would be is the fire pit just to the left of this sign? Notice how it's only the left side that's sliding down the sign?

Is the fire pit stationary or moveable? Did someone move it a bit too close to this sign?

In WI, we have fires in winter. A friend had a massive bon fire New Years Eve night and it was like zero degrees outside. I doubt your customer is adding tires to these fires but get a few teens together and there's no telling what they will do or what they will burn. Tires burn extremely hot...not that I would know of course, because I follow the law.

Not sure on the grill, maybe it's just behind the grills? Just a thought.

 

[JBurton]

If price is not a concern, i would look into using corian instead of stone, it still looks like stone, has a 50 year outdoor lifespan, and you can engrave and paint fill it, it will outlast the building.

Or even just use corian and print direct, as corian is a sealed, nonporous surface, it shouldn't have this issue if it was indeed the stone allowing moisture behind the printed area...
But really, corian is a wonderful material to work with, cuts like butter, polishes to a shine, and it feels premium.