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screen printing => Ink and Chemicals => Topic started by: rockerdude on June 23, 2014, 11:20:43 PM

Title: 100% Poly Questions!!!
Post by: rockerdude on June 23, 2014, 11:20:43 PM
Ok..So I know this has probably been discussed 1 million times on here before BUT... I have an order for 490 forest green pollys for a school. gold and lighter green print, no white in designs. I plan to use a white poly underbase.. thinking Epic Top Score white as underbase.. Should I go ahead and print the overs with top score also or go with regular plastisol for those? Same order has 400 BB jerseys that are 50/50 different design... should I use the top score for the 50/50's or change inks? I'm using rutland snap white on most prints now.. should I use that on the 50/50's instead of top score?
Title: Re: 100% Poly Questions!!!
Post by: brandon on June 24, 2014, 09:41:42 AM
Whether you use Wilflex or Rutland or whoever's ink system be careful of your flash times and dryer dwell time. That can make or break your print a few days later. We have all been there at one point! It is part of the learning curve.
Title: Re: 100% Poly Questions!!!
Post by: Ross_S on June 24, 2014, 01:31:45 PM
If you go with Top Score on everything you can drop your temperature by atleast 20 degrees (depending on dryer maybe more).  Results in a softer smoother print and less chances of scorching or dye migration.  Top Score works on both materials.
Title: Re: 100% Poly Questions!!!
Post by: blue moon on June 24, 2014, 03:17:35 PM
more ink the merrier when it comes to blocking dye migration and dye sublimation. If you use different inks, make sure they cure at the same temperature otherwise you will burn one to cure the other (if one cures at 280 and the other at 320, you will burn the 280 ink at 320 degrees needed to cure the second ink).

pierre
Title: Re: 100% Poly Questions!!!
Post by: Frog on June 24, 2014, 05:12:26 PM
more ink the merrier when it comes to blocking dye migration and dye sublimation. If you use different inks, make sure they cure at the same temperature otherwise you will burn one to cure the other (if one cures at 280 and the other at 320, you will burn the 280 ink at 320 degrees needed to cure the second ink).

pierre

That's a good place to use a low cure additive like the one from International Coatings
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on June 24, 2014, 09:31:14 PM
After thinking about it and taking your guys awesome advice.. I'm probably going to go with top score for under and overs on both. Its a school order and same colors on 3 different designs. The order also has 300 sports grey 2000's . With an auto prepaid reorder for the fall. I'm a Union printer, so all the local schools have been contacting me this last couple weeks! I may as well get used to the polys!!!
Title: Re: 100% Poly Questions!!!
Post by: TCT on June 24, 2014, 09:51:41 PM
You shouldn't have any issues with a Gildan 2000 sports gray and dye migration. I have never had that be a issue, and we just use or regular cotton ink.
Title: Re: 100% Poly Questions!!!
Post by: balloonguy on June 24, 2014, 10:23:13 PM
You may find using a gray underbase will help block dye migration. You want to go with something dark enough that it will overpower any migration but still be bright enough to make the top colors pop. I think the gray we lean on is russel gray.
Good luck.
matt
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on July 03, 2014, 12:46:20 AM
Ok... so started printing these today using the Top Score white for under and Top Score gold and Kelly for the overs! Was running at around 310 with ir gun right in the middle of dryer. streched a few.. lil bit of cracking.. I uped the temp to 320ish... Still cracks... Thought I was under curing so I did a few at 340 with one hitting 362ish on gun. Well... still cracked so I stopped.. Washed two including the 362 shirt. Cracking. I called nazdar and the dude told me that I had REMELTED the ink? I've never heard of this. Says I uncured the ink. Basically said I need to hit 300 at most on top layer for about 5 seconds with gun and I will be golden! Does this make since to anyone? My biggest fear is having all these shirts returned undercured! 
Title: Re: 100% Poly Questions!!!
Post by: Ross_S on July 03, 2014, 07:29:51 AM
I've heard of this but seen it happen when flashing.  If anything should of happened the ink should of overcured or scorched.  What kind of dryer do you have gas or electric and what length of heat chamber.
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on July 03, 2014, 07:54:09 AM
Electric 4 foot chamber
Title: Re: 100% Poly Questions!!!
Post by: Ross_S on July 03, 2014, 10:20:45 AM
You might be undercured.  How long are they in the heat?

Ross
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on July 03, 2014, 10:37:00 AM
Right at 24 seconds in the chamber?
Title: Re: 100% Poly Questions!!!
Post by: jvanick on July 03, 2014, 10:59:54 AM
I assume you don't have a donut probe?

sounds like under curing to me too... remember that the IR guns are measuring reflected heat, so that number could definitely be way off.
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on July 03, 2014, 11:11:17 AM
Anybody know a good place around Indy to get a probe thats not gonna kill me price wise? lol
Title: Re: 100% Poly Questions!!!
Post by: sqslabs on July 03, 2014, 11:25:31 AM
Anybody know a good place around Indy to get a probe thats not gonna kill me price wise? lol

I grabbed a used Aeroflex last week on Ebay for $70 shipped, they're around if you search a bit.  Sounds like you may need it a bit quicker though.
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on July 03, 2014, 11:40:47 AM
At 330 on the gun it seems to not be cracking? Just afraid to roll with it!!!!
Title: Re: 100% Poly Questions!!!
Post by: alan802 on July 03, 2014, 01:04:32 PM
If the gun is reading 310 then it's likely the ink temp at the threads is only around 260, 270 maybe.  If you had a reading of 360 then an average ink deposit should have reached around 320 to 330.  We use the donut probe all the time and I also use the IR gun along with it so I know what temps the ink is hitting when using the gun for a quick spot check.  Now this is with a gas, Sprint International dryer so our numbers won't likely be identical but it should give you an idea.  When my gun reads 370, I'm overcuring.  That's not going to have much of an affect on the print though, just wasting gas and time.  With the average plastisol ink, at around 350 the resins soften and you'll start to see some remelting so with the inks that cure at 290 I'd imagine (totally guessing here) the remelting temp would be close to 320.  Maybe some ink gurus will chime in on that. 
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on July 03, 2014, 06:07:28 PM
We'll.... I just ordered a probe on amazon for a Monday delivery. I just don't wanna take the chance on these coming back to me! Lol
Alan. It seems that there is about a 30-40 degree difference in the cure and the gun on your end. It may be close on mine also if I'm getting no cracks at 330ish and a cure temp of 290-300 on the top score ink. I'll know for sure Monday evening though!!!! Not cheap but.... It is worth the piece of mind I guess!!!
Thanks guys!!!
Title: Re: 100% Poly Questions!!!
Post by: Inkworks on July 03, 2014, 10:50:30 PM
Right at 24 seconds in the chamber?

I know this will go against popular opinion, but run a few through at 315-325F with a 90 second dwell in the oven and go from there.
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on July 08, 2014, 11:53:45 AM
Ok so got the probe and a ton of info from the great people at Nazdar and wilflex!!! Thank you again Peter and Nancy!!!!
In a 6 shirt group first shirt 324 on probe 410 on gun.  6th shirt 289 - 292 on probe 368 on gun.
But....no cracking in ink after.  But in the hot ones green outline is faded a little? 55 seconds in chamber. Do I just close my eyes and run with it or try to get it stabilized?
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on July 08, 2014, 11:54:55 AM
I guess my main concern is. Why in the hell is there almost a 100 degree difference in the gun and probe?
Title: Re: 100% Poly Questions!!!
Post by: Frog on July 08, 2014, 12:34:28 PM
Color of shirts, density of fabric, number of shirts in chamber can all affect temp readings.

In my dryer, an old American Phoenix Electric, it is not uncommon to get a spike of close to 395 on a gun to get a 310-320 cure down to the bottom of an ink layer. This high reading is only for an instant just before exit.
Title: Re: 100% Poly Questions!!!
Post by: Colin on July 08, 2014, 01:20:31 PM
It is all about retention time in the oven.

It can take at least 30 seconds - or more - for a thicker ink layer to reach cure temp at the BOTTOM of the layer.  It's all about how fast the ink can absorb heat.

If you are able:  You can flash the shirt just before pulling it off the press to elevate the temperature of the ink before it enters your dryer.

Also:  all dryers have heat flustuations.  This is normal.  This is part of why you are seeing a large swing on temps.  Also the aforementioned absorption of heat by garment and ink.  This pulls heat from the chamber and your dryer now has to ramp up the heat.
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on August 05, 2014, 12:32:02 AM
Ok... Been so busy haven't had time to come back and thank everyone for their help! Order was delivered on time and cured!!! Thanks again to The fine folks at Nazdar and Wilflex!!! On a great note... They sold out of the polys in like 4 days and just placed a reorder for 300 more as soon as I can get them! Again, thanks to everyone for the pointers. You guys ROCK!
Title: Re: 100% Poly Questions!!!
Post by: rockerdude on August 05, 2014, 12:34:13 AM
Almost forgot.... LOVE the top score ink!
Title: Re: 100% Poly Questions!!!
Post by: pwalsh on August 05, 2014, 07:16:49 AM
Ok... Been so busy haven't had time to come back and thank everyone for their help! Order was delivered on time and cured!!! Thanks again to The fine folks at Nazdar and Wilflex!!! On a great note... They sold out of the polys in like 4 days and just placed a reorder for 300 more as soon as I can get them! Again, thanks to everyone for the pointers. You guys ROCK!

Danny:  Thanks for the update, and for the kind words of recognition for Nancy Brown, Steve Hedge and the Technical Services Team at PolyOne Wilflex.  These folks are a great resource that provide a fantastic level of knowledge and support with challenging print applications.  I'm glad to hear that everything worked out so well, and that the customer is coming back with reorders.