"Burn" looking marks on material

[rydods]

There's a sign we put up last year and it looks as though the material or laminate is darkening in a couple of spots (photos attached). Any idea what might be causing this or how we can avoid it. It seems to be only at the top of the sign. Material used, Lumina 7300 reflective with Avery 1360 gloss laminate.
Quick note, the posts were stained before we installed the sign and it's at the edge of a farm field in the middle of nowhere so I kind of doubt vandalism would be the issue.

 

[Solventinkjet]

The materials you used seem to be fit for the job. If you're printing solvent ink, how long did you let it off gas before laminating? If not long enough, it can cause issues like this.

 

[DL Signs]

Did you lay it wet? It's the best way to lay some reflective, but if you trapped moisture in it and put it out in the sun, all kinds of mean, nasty, rotten, ugly things can happen with the reflective materials. Depending on what you used as an application fluid, like home brew soap & water based ones can cause mold too if they're made too concentrated and get trapped. I throw this out there because it looks like it's happening in a non printed area, but just like Solventinkjet says, you really gotta let solvent inks out-gas.

 

[Solventinkjet]

Did you lay it wet? It's the best way to lay some reflective, but if you trapped moisture in it and put it out in the sun, all kinds of mean, nasty, rotten, ugly things can happen with the reflective materials. Depending on what you used as an application fluid, like home brew soap & water based ones can cause mold too if they're made too concentrated and get trapped. I throw this out there because it looks like it's happening in a non printed area, but just like Solventinkjet says, you really gotta let solvent inks out-gas.

Good call, both material data sheets say no wet applying so could be that as well.

 

[Mike Paul]

I agree never apply reflective wet.

That looks like U/V damage burn to the silver in the reflective material. Seen it happen before on the best material; especially on Black trucks that hold a lot of heat in the sun.

Anything reflecting on it like a bracket or something?