Discussion Vinyl Prep.

[Jeremiah]

Just had a thought for a helpful post for newbies . Had an order for a banner yesterday. (Cut vinyl) . Laid it out, scrubbed it with Denatured Alcohol. Dried and applied vinyl. Hung it outside on a fence. A few hours later some edges were comming loose
Huh ????? My guess was a bad can of DA. So I redid the whole thing before customer came in. What do you use for clean prep on banners or coroplast?

 

[Gino]

Can you tell us what kinda material the banner was, manufacturer and other incidentals and what brand and grade of vinyl was used. That more likely has something to do with it, rather than bad alcohol.

Usually just wipe a banner down with plain water for die-cut vinyl. Ya only wanna get dirt off. Digital prints need a little more oomphf.

 

[Jeremiah]

Orical 651 . A pallet full of sign warehouse banners that I bought from someone closing their doors 10 oz stuff yellow color

 

[Gino]

Scrim, poly...... ??

 

[kcollinsdesign]

Orical 651 . A pallet full of sign warehouse banners that I bought from someone closing their doors 10 oz stuff yellow color

There's your problem (Oracle 651). Not to disparage 651 (a great product when used appropriately), but I would only use a calendared vinyl on temporary signs and for best results a rigid substrate without plasticizers. Wiping with alcohol only removes the surface plasticizers, and the modulus coefficient of a relatively stiff calendared vinyl on a more flexible substrate is a recipe for eventual failure (probably sooner than later).
There is a reason people are dumping their blank banners. When you can buy fully printed 13oz. reinforced vinyl banners with hems and grommets for 89¢ / sq. ft. or less, and have them drop shipped directly to your client, nothing else makes sense.

 

[Jeremiah]

What about temperature it is applied? I am not asking for help. This a discussion for others also. I have only had 2% with any problems. I aim for 100 % success.

 

[signbrad]

What about temperature it is applied?

Most 3M bulletins (such as Bulletin 5.1) specify 60-100 degrees F for application temperature (though I think Orocal says 46+ degrees for 651).
So temperature can be an issue. High humidity can create an adhesion problem, too, as mentioned in Bulletin 5.1.

Also, the older the banner material is, the more of a problem plasticizer will be.
Plasticizer migration is why many vinyls for cut graphics, including Orocal 651, have a rated "2-year shelf life." Over time, as the plasticizer migrates out the adhesive side, the adhesive is compromised. The adhesive doesn't "dry out," as some think. It just becomes contaminated by the plasticizer. A hot warehouse can accelerate this migration. Also, cheaper vinyls have cheaper plasticizers. That's one of the ways they make a vinyl cheaper. So migration may be more of a problem on cheaper vinyls.

In like manner, with vinyl banner material, plasticizer migrates to both front and back of vinyl and can prevent adhesion. Bulletin 5.1 lists recommended solvents for substrate cleaning. The most aggressive in the list are xylol (a lacquer thinner) and "lacquer thinner," (from a hardware store or paint store, "lacquer thinner" will be a solvent mix which varies in strength by brand, depending on what is in the mix). A simple alcohol wipe may not be aggressive enough.

Bad batch of denatured alcohol? Possible, I suppose, but not likely, in my opinion.
Denatured alcohol is simply ethanol that has been intentionally contaminated by a small amount of a poisonous additive (often methanol), "denaturing" it. Various other contaminants are used to denature ethanol also, even gasoline. So I suppose a particular brand or batch could be a problem.
I think it is noteworthy that 3M recommends isopropanol, rather than ethanol or "denatured," as the alcohol of choice for cleaning. Specifically, two parts isopropanol, one part water.

More likely, though, an adhesion problem is caused by plasticizer on the surface, or the vinyl is not dry enough, or adhesive on the cut vinyl that is contaminated by plasticizer.

I wouldn't rule out the comment from kccollinsdesign about 651 calendered vinyl, either. Follow your same procedures on the same banner material and test with a cast vinyl, including hanging it in the sun.

Brad in Kansas City

3M Bulletin 5.1.
http://multimedia.mmm.com/mws/mediawebserver.dyn?6666660Zjcf6lVs6EVs666TtMCOrrrrQ-