Prochem HXT CCI

[dirkdiggler]

I am gonna coat a few screens with it and YOU will do the exposure on Friday Mike, how does that sound?

[screenprintguy]

Awesome, looking forward to seeing you guys!

[3Deep]

Funny that you say that Screenprintguy, I've wonder about samples to as I got some qt sample that works really well until I get a gal or two and they are night and day.

[screenprintguy]

It was weird Darryl. I mean this one emulsion we tried, the quart sample coated great, exposed great, washed out great, held up on press great, reclaimed great. Got a 5 gal in, coated fine, exposures were way different, actually some odd reactions the next day checking washed out screens on the drying rack where the emulsion was bubbling like pimples on the shirt side of the screen. Did some contact through the channels, told to bump up exposure time, did that, but them images were very hard to wash out even after a long soak in the water tank. Then lots of pinholes which we never had with Chromablue, the pinholes might have been from having to beat at it to get the image washed out. Then when reclaiming, man, it was like reclaiming screens that had hardener. A same batch of reclaimed screens were also coated with Chromablue, and had no issues, so I'm tending to think it was a bad batch. Maybe froze at some point, not sure, things happen, but the time and effort and issues was a clear hint to go back to Chromablue for our plastisol use emulsion. I was trying to be cheap and save 10 bucks a gallon but that didn't save, ended up costing a bit.

[Homer]

OOps wrong post.

[Homer]

Mike -what exposure unit are you using on this stuff? I was talking with a few people about the wr-14 and i want to give it a try with our LED unit, but we are being steered towards the HXT...LED is a whole nother animal I think, not too sure if this HXT will be the ticket or not.

[screenprintguy]

We are using a 3k Tri-Light. I did some screens yesterday with HXT, 3 over 1 coating on 125 mesh, shot them at 600 LU, for this unit that's roughly 6 mins I believe. Remember for us, no glass or film using the I-Image. 1200 piece discharge run, double strokes, and zero breakdown or signs of wear after the wash out of the screen.

[Screened Gear]

We are using a 3k Tri-Light. I did some screens yesterday with HXT, 3 over 1 coating on 125 mesh, shot them at 600 LU, for this unit that's roughly 6 mins I believe. Remember for us, no glass or film using the I-Image. 1200 piece discharge run, double strokes, and zero breakdown or signs of wear after the wash out of the screen.

Why 3/1? Your printing discharge right? Is that with the rounded side of the coater? I do 2/1 with the sharp side and I have no break down with discharge. PhotoSharp 1000K exposed for 75 seconds. This emulsion has a huge window for exposure. I have done 150 seconds and it still washed out fine. The 75 seconds exposure time I have printed over 500 double stroke DC with no break down. I do have really dark film so that may play a part it the reason I can expose with such a large window.

Again why are you building a thick stencil to print waterbase? Not questioning you as much as trying to see if there is a benefit I am missing.

[screenprintguy]

Honestly my cci rep told me to go to 3/1 from the 2/1 we were doing. we were having an occasional pinhole issue. We went through making sure our screens were super clean, they were, he said try the 3/1. since then, no pin holes. It has low solids so I guess that may be a reason, not totally sure, but even with the 3/1 round edge, the stencil isn't nearly as thick as a 1/1 chromablue coated screen with the round edge. I have no idea how you are able to pull those times off with the photosharp 1k, but you can and that's awesome!!! I think we've had this chat before and you are in a very dry dry location right? We constantly battle humidity here, even with dehumidifiers, today is 80% in the shop.

[Screened Gear]

Honestly my cci rep told me to go to 3/1 from the 2/1 we were doing. we were having an occasional pinhole issue. We went through making sure our screens were super clean, they were, he said try the 3/1. since then, no pin holes. It has low solids so I guess that may be a reason, not totally sure, but even with the 3/1 round edge, the stencil isn't nearly as thick as a 1/1 chromablue coated screen with the round edge. I have no idea how you are able to pull those times off with the photosharp 1k, but you can and that's awesome!!! I think we've had this chat before and you are in a very dry dry location right? We constantly battle humidity here, even with dehumidifiers, today is 80% in the shop.

I have tried about 5 of CCI emulsions and this is the first one that I have no (well almost no) pin holes. I did add a whole house filter to my water in the washout booth. I think that played a big part in it. I have not measured my stencil with HXT. I don't think its to much thinner than it was with Aquasol HV. I am on my 6th or seventh gallon of HXT. I honestly am very happy with it. With Aquasol HV I was exposing screens at 20-35 seconds. I am in Arizona so my shop is very dry. Out of all the screens I have done with HXT I have only had 2 break downs. Both screens were not dryed over night. They were coated and then dryed for a hour flat in the screen rack then a half hour in front of a fan. I needed them. I usually let screens dry over night. I know my stencil thicknesses are less then most on here so that plays a part too. Honestly I would not use any emulsion that was longer than 2 mins exposure. I am easily distracted and waiting on the exposure unit drivers me nuts.

Do you filter your washout booth water? If not give that a try. My shop has horrible water.

[screenprintguy]

Water filter sounds interesting man!!! Our water is pretty nasty in Polk county, sometimes we can see marks on the screen mesh from the water that ran down after standing the screens up to dry. Maybe there is some nasty crud in the water itself. Seeing how you could tell a noticable difference from trying to expose a screen coated in the same day vs drying over night prooves this stuff needs to be dry as a bone. I just checked my room where my screens store and even with the ac and dehumidifier running its still 55% today  . Constant battle with humidity. I'm glad to hear the emulsion is working for you though, it is great when all is dialed in. I need to get ahold of an EOM meter to see where I am.

[Screened Gear]

This is the kind of filter that I have on mine. I have it hooked up before the hose and the pressure washer so all the water gets filtered. Its cheap like $40 at home depot. It uses RO filters.

I think I luck out on alot of things being in a hot dry area.

[tonypep]

Water filter sounds interesting man!!! Our water is pretty nasty in Polk county, sometimes we can see marks on the screen mesh from the water that ran down after standing the screens up to dry. Maybe there is some nasty crud in the water itself. Seeing how you could tell a noticable difference from trying to expose a screen coated in the same day vs drying over night prooves this stuff needs to be dry as a bone. I just checked my room where my screens store and even with the ac and dehumidifier running its still 55% today  . Constant battle with humidity. I'm glad to hear the emulsion is working for you though, it is great when all is dialed in. I need to get ahold of an EOM meter to see where I am.

Standing screens to dry=set up for failure. Horizontal= better

[screenprintguy]

Water filter sounds interesting man!!! Our water is pretty nasty in Polk county, sometimes we can see marks on the screen mesh from the water that ran down after standing the screens up to dry. Maybe there is some nasty crud in the water itself. Seeing how you could tell a noticable difference from trying to expose a screen coated in the same day vs drying over night prooves this stuff needs to be dry as a bone. I just checked my room where my screens store and even with the ac and dehumidifier running its still 55% today  . Constant battle with humidity. I'm glad to hear the emulsion is working for you though, it is great when all is dialed in. I need to get ahold of an EOM meter to see where I am.

Standing screens to dry=set up for failure. Horizontal= better

Just had 4 new screen racks show up today, so that we can stop doing that!! Now we can dry flat 

[Screened Gear]

Tony do you mean drying coated screens? I have dryed decreased screens vertical ever since a started printing.