How to tell the difference between UV & Aqueous

[eric@associatedprinting]

Does anyone know how to tell whether a printed piece has been aqueous coated or UV? The piece I have does not look super smooth but the customer doesn't know how it was printed.

 

[jlind]

Re: How to tell the difference between UV & Aqueous

Eric:
If it's water based, you can dissolve it away with an ammonia solution, like Windex? If it's UV, try a tape pull, see if it comes away clean from the surface. UV is more slippery, from silicones. Another thought, a ball point pen should write on an aqueous coating (same as Indigo Sapphire...) but not on UV.
John Lind
Cranberry Township, PA
724-776-4718

 

[UVMAN]

Re: How to tell the difference between UV & Aqueous

In my experience AQ even at a high gloss will still have a MATTE TYPE OF look. UV on the other hand should have a very nice high gloss. although there are different types of UV if the sheet came from an offset press chances are it 's AQ. and if it's a digital press chances are it can from a UV Roller type of coater Like my XTRA Cure UV Coater.
please fill free to call for more help.

 

[bearwithme]

Re: How to tell the difference between UV & Aqueous

Not to throw a wrench in the works but...
We print UV litho on plastic. You can certainly get matte uv coating, writeable uv coating, and gloss uv coating. The writing test may not work if it has writeable uv coating on it.

 

[tmason]

Re: How to tell the difference between UV & Aqueous

Try smelling it. UV has a distinct odor.

 

[arfamoe]

Use a regular felt tip marker (not a sharpie) and draw a line on the coating, if the coating is UV the felt ink will 'Bead' and not stick, if its waterbase the line will stick to the coating.

 

[Freeman A.Gain]

Not always, but..

Not always, but..

I will agree with bearwithme! The writing test no longer applies 100%. Now, having said that, it is definately one test you can do. Not all UV coatings are writeable, and more often than not, those are special uses. So if a jiffy or pen cannot write on it, then it is UV. Smell test is also good, if you know what you should smell! Typically, UV gloss coating will be very shiny!

 

[Cedarman]

Determining if UV coated

Determining if UV coated

Folks,

I'm new here so excuse mistakes or indiscretions. I need your expertise.

My company makes household products out of aromatic eastern red cedar wood (hangers, blocks, balls, sachets, etc.).

The relevant point is that we always apply a UV coating to our packaging in the area where the wood will touch the printed cards (e.g, blister cards). Otherwise the natural oils in the wood will cause the underlying inks to bleed all over and ruin the package and product.

We have done this for years and never have problems.

Recently a large customer of ours (nationwide retail chain) required us to use a non-U.S. printer for some blister cards. The cards looked okay, UV coated area was appropriately glossy.

However, after packaging product we have found that the "UV coated" area under the cedar wood became very wrinkled and 'orange peel' looking. The ink has not bled so far, just the orange peel effect.

Does anyone have any idea why this might have happened? We have never had anything like this in the past.

Is there a simple test I can perform on the supposed UV coated area that will tell me if this is a true UV coating?

I tried the felt tip test and it does bead up on the UV surface. Also tried ball point pen and it wrote on the UV surface.

Are there different types of UV coating that might account for this?

Any help/suggestions would be greatly appreciated.

Thanks in advance

 

[Cornishpastythighs]

I would imagine there are hundreds of UV coatings of different levels of quality out in the market place. The felt marker test is a good cheap basic test that has its exceptions, some UV coatings are classed as foil stampable/imprintable these coatings have certain ingredients removed to allow the foil to stick to the coating and can be wrote on. If I read this correct, you used to apply the UV coating yourself or at least had some form of control over the process, now you have no control and have no idea of the quality or application process of the problem coating. Time to visit your 'new' supplier if they are not 10K miles away and put in some quality specifications, Its your reputation hanging on the shelves mate.

 

[Vee]

Time to visit your 'new' supplier if they are not 10K miles away and put in some quality specifications, Its your reputation hanging on the shelves mate.

Well said. Even if they are 10k miles away, you need to check them out; and clearly communicate your expectations.

 

[jlind]

If the coating is orange-peel-like, then it is probably UV, cured before it could level out or it didn't wet the inks beneath it properly. Maybe the inks had wax in them, or it was a cheap UV coating. Or it was over cured.

One thing for sure, the price was right for the national retail chain, and, after all, does anything else matter?
Hmmm, do you think the national retail chain and their supply chain management managers bear any responsibility for this? Have you sent samples to their printing experts to see if they know what this is or if it is acceptable for their shelves?

Interesting problem, since Oil of Cedar would be a pretty good solvent for offset inks, and, depending upon the molecular backbone of the UV coating, could swell the UV coating too.

Please let us know what you find out.

John Lind
Cranberry Township, PA
724-776-4718

 

[Cedarman]

Unfortunately they are 10K miles away, literally. I am trying to plan a trip over there next month.

We did not apply the UV but had it done for us.

I need to get some education on UV coatings, what are the types, methods of application,e tc.

Can anyone suggest sources for this?

Thanks

 

[Cornishpastythighs]

Application methods vary, regular inline roll coaters and anilox coaters for sheetfed/web fed presses to offline screen coaters and Digital coaters. I can only comment on sheetfed and web coaters and do not have any experience with the other types. I gather it's only orange peeling where the wood comes in contact and that when you receive the printed/coated product from your offshore supplier the orange peel is not evident. As the world of UV coating is so vast I would certainly consult your previous coating supplier and have them evaluate/comment on the problem and give you some advice/education, your planned visit is a wise move although you need some knowledge to know what to look for when you are there.

 

[CD102]

Boy, it sounds like Wal-Mart is involved in this.

 

[Cedarman]

Actually it's the other giant.

 

[Flexo Grunt]

Visited a "Nation wide retail chain" (actually its Global) to purchase some Cedar rings and it jogged my memory of this thread. Half the blisters were falling of the cards and there defiantly is a varnish problem by the looks of the empty cards still hanging on the rack.

 

[Toyo Tech]

very simple test for identifying UV vs Aqueous: get hold of some acetone/MEK or even some nail polish remover, get some cotton wool soaked in the solvent and rub smoothly and firmly....if the varnish and ink are destroyed in less than 8 or 10 rubs then u have an aqueous coating. UV coatings will last many many more rubs!

 

[Cedarman]

UV v Aq Test

UV v Aq Test

Great! Thank you.

 

[saifu7]

UV vs Lamination, need help

UV vs Lamination, need help

I am planning to buy a Spot UV which can do flood UV too. It has curing system. Definitely not Aqueous based. now the problem is currently I m offering my clients all the business cards with either matt or gloss lamination. but after I get the UV machine i will offer business cards with matt or gloss UV. My concern whether or not as a look do the easily noticeable??? i have sample on gloss uv and compared with gloss lamination, which looks pretty same and you can defer them only by tear them. i don't / never seen matt UV, therefore asking if they look same (99% would do) or nearly 90% same look?

another strait question, whether i can sell them (UV) by saying UV MATT / GLOSS LAMINATED business card or just MATT / GLOSS LAMINATED business card?

 

[jonprintz]

Unfortunately they are 10K miles away, literally. I am trying to plan a trip over there next month.

We did not apply the UV but had it done for us.

I need to get some education on UV coatings, what are the types, methods of application,e tc.

Can anyone suggest sources for this?

Thanks

There are many different UV formula's available and many manufacturers of varying quality. What you need for your application is a formula that is highly water resistant. Many manufacturers make this claim but there are only 2 ways to determine whether their claims are true or not.....both involve testing. You can place some tags outside in a limited access area (or the roof of a building) this will take at least as long as you plan for them to last in the field, or test them in an accelerated testing machine that simulates weathering and UV exposure.

One source for accelerated testing is the QLab Corporation. They can place your samples in a machine or in their outdoors testing facility.

The MEK test is the best way to determine what you have but it is really more an indicator of cure than type of coating. Lightly cured coatings will fail as quickly as AQ coating in that test as will certain substrates with fully cured coatings / inks. Good substrates / inks / coatings / cure will easily last well beyond the test outlined.

The marker test will also be an indicator (Sharpie does work well for this also) but with the writeable coatings available is not always a sure indicator.

UV coating will almost always appear be clearer than AQ and once you have learned what both look like it is usually apparent which one you are looking at.

Hopefully your problem has already been solved to your satisfaction.