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screen printing => General Screen Printing => Topic started by: Rob Coleman on October 17, 2016, 01:09:23 PM
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Wilflex out out a nice little piece on wet-on-wet printing. Short but succinct.
http://www.polyone.com/files/resources/Wilflex%20T_T_WetOnWet_v3.pdf
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Wilflex out out a nice little piece on wet-on-wet printing. Short but succinct.
[url]http://www.polyone.com/files/resources/Wilflex%20T_T_WetOnWet_v3.pdf[/url] ([url]http://www.polyone.com/files/resources/Wilflex%20T_T_WetOnWet_v3.pdf[/url])
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When I first started, we used Wilflex's SSV, then they came out with MCV (multi-color vinyl?) that wouldn't bleed into each other, like black lines against a yellow fill... there was no flashing yet...
Steve
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"Controlling under-base flash temps— Monitoring
the flash temperature for the under-base white
will help with the wet-on-wet printing. If the flash
unit approaches cure temps, the platens can
become too hot, which can thicken the inks and
build/dry on the back of the screen. Ideal pallet
temperature should be in the 180°–200° range.
Build-up image blocking and color
loss will be the result."
Anyone run their boards that hot?
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"Controlling under-base flash temps— Monitoring
the flash temperature for the under-base white
will help with the wet-on-wet printing. If the flash
unit approaches cure temps, the platens can
become too hot, which can thicken the inks and
build/dry on the back of the screen. Ideal pallet
temperature should be in the 180°–200° range.
Build-up image blocking and color
loss will be the result."
Anyone run their boards that hot?
this would absolutely kill most of our inks..
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Wilflex out out a nice little piece on wet-on-wet printing. Short but succinct.
[url]http://www.polyone.com/files/resources/Wilflex%20T_T_WetOnWet_v3.pdf[/url] ([url]http://www.polyone.com/files/resources/Wilflex%20T_T_WetOnWet_v3.pdf[/url])
Sent from my iPhone using Tapatalk
When I first started, we used Wilflex's SSV, then they came out with MCV (multi-color vinyl?) that wouldn't bleed into each other, like black lines against a yellow fill... there was no flashing yet...
Steve
You are dating yourself! :o
I started working for Wilflex in 1987 up until 2012. Most people don't know those abbreviations - SSV stood for Silk Screen Vinyl and was the original Athletic ink (think Russell). MCV was indeed Multi-Color Vinyl and it had about a 20% water blend into the plastisol formulation. These were the only two main plastisol lines until MP (Multiprint) came along followed by Genesis, and then ultimately the Epic line.
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"Controlling under-base flash temps— Monitoring
the flash temperature for the under-base white
will help with the wet-on-wet printing. If the flash
unit approaches cure temps, the platens can
become too hot, which can thicken the inks and
build/dry on the back of the screen. Ideal pallet
temperature should be in the 180°–200° range.
Build-up image blocking and color
loss will be the result."
Anyone run their boards that hot?
I thought that a bit hot myself..... maybe someone from the Wilflex team will chime in.
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Doubt it
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Anything over 140* on pallet temp and we start to see phase separation and buildup of our inks. Some colors worse then others but with all my testing 140* or even close to that and you will start to build regardless of how good your ink is. That seems like some mis leading info if you ask me
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105-110 is perfect for us. no hotter.
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Rule of thumb if you can't touch the underside of your pallet for 3 seconds or longer it's too hot.
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105-110 is perfect for us. no hotter.
BOOM!
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105-110 is perfect for us. no hotter.
Given the gel temp of ink how do you keep your pallets from climbing over 110? Here in New Orleans I am thrilled to keep a 12/14 with 2 flashes in the 130s and often find ourselves around 150 even running both flashes at .6 seconds and at 60% power. If we lower the flash time or power any more then the ink doesn't gel.
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105-110 is perfect for us. no hotter.
Given the gel temp of ink how do you keep your pallets from climbing over 110? Here in New Orleans I am thrilled to keep a 12/14 with 2 flashes in the 130s and often find ourselves around 150 even running both flashes at .6 seconds and at 60% power. If we lower the flash time or power any more then the ink doesn't gel.
By gel if you mean sticky to the touch then you are over flashing it. Should feel like warm paper.
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some inks we used required more heat to get rid of the after flash tack. 180-200 would cook the ink for us, no question about it. I'd like to run our platens at 120, but that is not always the option. As mentioned, two flashes can be one of the reasons for more heat. We run two flashes maybe once or twice a month, so generally not a big issue.
pierre
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Anything over 140* on pallet temp and we start to see phase separation and buildup of our inks. Some colors worse then others but with all my testing 140* or even close to that and you will start to build regardless of how good your ink is. That seems like some mis leading info if you ask me
Danny, may I ask: you're refering to buildup on the back of screens yeah? I've never heard the term 'phase separation' before so am curious... My printers often deal with buildup on high color jobs (thinking 6-8 colors including an underbase/flash/cooldown at the front). I always assumed the buildup was because excess print pressure and low tension screens... ongoing issues I battle... But we do print using hot flash temps, indexeing from the flash at around ~150-160 sometimes. Again, I've considered this a function of having not the best UB white which held its tack too long. but maybe I'm looking at it from the wrong angle.
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For discussing build up we need to know:
inks,
mesh counts,
mesh tension,
squeegee hardness,
sharpness of squeegee,
Temp of boards while running,
cool down stations?
stroke speed,
number of strokes,
Garment type can come into play as well.
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Hey all!
I want to apologize for this mistake. It's all my fault. I inadvertently mis-edited this document and it ran some thoughts together.
We are fixing this document as soon as possible.
Obviously the thought was that the platens and ink performs better when warmed up. I usually will start my run when the platens hit 100 - 120 degrees, but the bare platen can reach higher. For the most part, once you load the shirt, it will take the surface temperature down. Monitoring the flash units to our specifications will keep the platens to a safe temperature.
The ink surface temperature will need to reach 180-215 F in order to flash. (see the PIB for the product you are flashing)
thanks for your attention (for reading) and your understanding (I hope)!
Ray Smith _ Wilflex
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To expand a little for other printers:
Fast Flash inks can flash as low as 150 F. Typically around 160 F. A normal base white will flash within the parameters Ray has set forth.
The reason why more whites/inks are not fast flash: Storage and transport.
Sitting on a shelf, historically those inks have thickened up more over time.
During transport, the sides of a truck can reach well over 120 F. Internally the ink can sit at 110 F or higher for extended periods of time. This will cause the ink to start "flashing"/gelling up. Becoming much thicker and unusable.
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FYI: Ray and Wilflex have update the piece to reflect proper platen temps. Same link should work.
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