Screen Printing on Powder Coating

[mimosatexas]

I have had multiple requests this last month for screen printing on powder coating (metal with polyester based coatings as far as I have been told), and have been researching it a bit while people get their product ready for me.  I will be getting my first batch of product from a company this week and wanted to start a thread to see if I could get any more info before beginning in house testing of the inks and process.

I have read some threads that mostly answer the basics (or so it seems) here:

http://www.gigposters.com/forums/showthread.php?t=155536
http://www.t-shirtforums.com/plastisol-ink-screen-printing/t83458.html
http://www.finishing.com/72/68.shtml

My main concern is making sure that I am offering the best solution at the best pricing of course, but also ruling out options that might offer benefits on lower run sizes and odd surfaces.  I would like to know the pros and cons of all the options out there so I can respond quicker to these kinds of requests in the future and potentially get more of this kind of business down the road.

A few specific "issues" I foresee:
-rough surface leading to problems with high detail and clean edges.
-low run sizes leading to large amounts of wasted ink due to the need for a catalyst.
-multiple color registration due to the inherent variety in the shape and size of the substrate and the requirement for jigs.

I love the idea of some kind of transfer, but I was able to peel up the M&R label on my Kruzer with just my fingernail on the very first attempt, and it is new, inside, and the label has never been exposed to the elements or any kind of cleaner beyond a wet paper towel, so I need something that will have more durability.  I'm not sure if the M&R label is just a standard vinyl or what, but I'm thinking vinyl is out. 

I did come across this: https://www.youtube.com/watch?v=zfJeLc3ANJo ...not sure if anyone has tried these.

Thanks!

[TCred]

We pad print onto powder coated products reguarly, but the ink and adhesion problems are the same.

Here is what we have found.

1) If the powder coater has oven cured the product at more than recommended temperature (they all do as it's faster) the surface becomes ink unfriendly and adhesion while initially looking OK degrades quickly over a few weeks.

2) The sufrace needs to be cleaned with agressive solvents to fix this.

3) We use Printcolor 784 with 4:1 700-HDA hardener.

4) we always heat cure the ink at 70 degrees C in our oven for as long as practical.

Cheers

[mimosatexas]

Thanks for the info!

[UnderPressureSP]

Never print power coated stuff but I love ink and reading labels.  I may suggest a solvent nazdar ink and a clear coat on top to protect the ink.   I have a over print clear solvent ink for nazdar i been using to test flake which would protect the ink under the print.  Solvents seem to hold up to best in the elements.  Also they sell additives to make the ink more chemical resistant if i remember right.  I also have some vinyl solvent ink that you could test also.  It's really hard to test sign durability because you only know once it been in the elements for year.  The clear coat on top seems the best solution for durability.   Your best bet is to talk to a ink tech at nazdar and I am sure they will give you great advice.  I been using them a lot for my flat stock R&D and they been a great help!

[ZooCity]

It might be detrimental to the overall finish but sanding the powder coat with some high grit to give it some tooth would probably help.

A cad cut transfer vinyl with a clear overcoat might be the ticket too. 

Interested to hear what you come up with.

[tancehughes]

Not that I'm quite on topic here, but we actually offer powder coating here at our business (we have a metal fab shop side of our business) and I've never really thought about printing on powder coated items. We design a brand of home decor products that are cut out of our CNC machine and then powder coated, and I'm wondering if we could add screen printed designs on top of them as another design element. If anyone wants to take a look and offer their thoughts on it let me know - www.metalunlimited.com

[hoogie]

We do thousands of plates that are powder coated. Nazdar...There your friend. ADE series with cat and thinner. Air dry and put the second color on. After 24 hours dry time, you can take a screwdriver to the print trying to scratch it off. That might help ya.

[pwalsh]

I have had multiple requests this last month for screen printing on powder coating (metal with polyester based coatings as far as I have been told), and have been researching it a bit while people get their product ready for me.  I will be getting my first batch of product from a company this week and wanted to start a thread to see if I could get any more info before beginning in house testing of the inks and process.

My main concern is making sure that I am offering the best solution at the best pricing of course, but also ruling out options that might offer benefits on lower run sizes and odd surfaces.  I would like to know the pros and cons of all the options out there so I can respond quicker to these kinds of requests in the future and potentially get more of this kind of business down the road.

Mimosa:  You have already received some really good advice from the TSB Pro's (which is why I love this forum) but I thought that I'd chime in anyway.  Nazdar has a number of inks that will provide excellent performance on polyester powder coated metals, but before making a recommendation it's important to understand a few things about your process and application.

(1)  Is the item for indoor or outdoor use?
(2) If being used outdoor what durability is required?
(3) Does the ink need to be solvent and/or abrasion resistant?
(4) What method are you using to dry /cure the ink? (Example; Air Dry, Forced Air, or UV Curing)

Once you get this information together you should feel free to call the team at GSG (Nazdar's 2nd best distributor ) or drop an email into the Nazdar Technical Applications Specialisits at InkAnswers@Nazdar.com for a qualified recommendation.