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screen printing => General Screen Printing => Topic started by: Flash Ink on March 14, 2016, 04:40:11 PM
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I am sick of beating my head against a wall. We have a 8/10 Javelin and I am trying to use the resources at my disposal. Namely, the wealth of knowledge on this board. We are using Rutland HO inks and keep getting pick up on the screens leaving my last print looking like garbage. They are going on dark garments. We have been printing manual for a long time, but realize that there is a learning curve when printing on an auto.
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Pickup on subsequent screens and the resulting muddiness can be exacerbated with inks not meant to be printed wet on wet, and made even worse with lower tension screens.
Either of these the case?
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My distributor keeps telling us that the Rutland HO inks are good for autos and just let the buildup on the back of the screens accumulate and we should be fine? Should I be using different inks?
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need some more info...
1. print order?
2. flashes? how long and where/after what color?
3. screen mesh type and mesh counts.
4. what squeegee durometer, and are they new or old?
5. how much pressure are you using? <-- I know this one is hard to judge on the javelin.
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We have found that making sure our ink was warm was key, it allowed proper squeegee pressure (we had too much pressure when printing with cold ink), which fixed our muddiness issues. We are not using Rutland inks, so I don't know if those are made for WOW or not. We do allow the accumulation of the ink, in fact, we build it up in the beginning of a SIM Process print job so the first and last prints look the same.
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to reply to jvanick, that is what I am trying to learn. I want to know what you guys would do for print order, flashes, screen mesh for each layer and so on. We have newish triple duro squeges, new screens and 4 flashes that can be used.
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you'll need about 0 prints for the ink to settle in correctly on the back of the screens. If it's pulling after that, look for different ink or get some additives that will make it WOW (wet on wet) friendly.
generally, HO inks are not designed for WOW.
pierre
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what does the manufacturer's spec sheet say? If you don't have one, dig it up! It should list the mesh counts and everything else you kneed.
for us, all the top colors would go on 305 mesh.
pierre
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I think Tiffany was giving advice on sim-process work... we like to get some build on the bottom of the screens to help with colors blending.
for standard spot color work, we go with a 160S for our underbase, and 225S for any top colors.
HO inks typically have a lot of white pigment in them to help build that thick opacity so they'll build a lot worse than non HO colors.
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My distributor keeps telling us that the Rutland HO inks are good for autos and just let the buildup on the back of the screens accumulate and we should be fine? Should I be using different inks?
3 of the colors in this design are notorious for sticking in the Rutland HO series. We used to fight that a lot. You need to get some after flash tack additive. It is pretty much the only thing you can use to get it to stop sticking. You also need to watch the ink temps and pallet temps. The Rutland plasticizers like to change their characteristics in smaller temp swings for some reasons. Everything can be running great and then a simple 5 degree rise can cause it to stick like a mofo. Squeegee pressure and off contact can make a huge impact to. too much pressure can make it stick. If you go to a higher than normal off contact which for us is anything more than a 1/16th of an inch you will get a better peel.
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I think Tiffany was giving advice on sim-process work... we like to get some build on the bottom of the screens to help with colors blending.
for standard spot color work, we go with a 160S for our underbase, and 225S for any top colors.
HO inks typically have a lot of white pigment in them to help build that thick opacity so they'll build a lot worse than non HO colors.
Not exactly accurate..... different binders and fillers etc. but not white. Either way tight screens, proper mesh selection, sequencing, squeegee variables, off contact must all be dialed in.. You may need to bring someone in to help with all that but once this is accomplished, you will find that this is as easy as it gets.
Of course we would print it in discharge and move on ;)
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Have you given Kelly at RC a call yet and walked through the issues with him?
I too have noticed the "tackiness" issues with Rutlands inks when at various temperatures.
Their response is to add detack - which is a plasticiser. It makes the inks "wetter" for better peel, but conversely stinks and makes flashing take longer - or add curable reducer. Curable reducer has some resin in there, but is mostly plasticiser.
Flash Ink: Could you fill us in on print order/squeegee selection/mesh counts/strokes/off contact/screen tension/flashes being used?
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You need 5 colors and have 8 heads minus the flash
It will be hard to do in one revolution you will have no cooling station.
You can base down your HO ink (me I use 30% Shape or EPIC mixing base)
This is how I would print this on an 8/10 auto
head 1 --> black - 230 - no underbase
head 2 --> white - 120
Head 3 --> flash
Head 4 --> Purple - 305 - base down ink
head 5 --> Yellow - 230
head 6 --> Flash
head 7 --> Green - 305 - base down ink
head 8 --> H/L white - 230
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Thank you Willy, thats what I was looking for.