TSB
screen printing => Screen Making => Topic started by: jvanick on October 03, 2015, 05:52:45 PM
-
how does everybody dry their screens after reclaim?
I know some of you lean them against the wall... -- we do the same, but occasionally water will get trapped between the upper edges of the 2 frames and then drip down when you separate them.
we've tried flat, but those screens ended up with water spots (even after using DirectPrep2 and other degreasers) -- we have REALLY hard water here at the shop, and no water softener.
any other ideas?
-
Put the screen on an angle in the rack. Water will roll down to one side and off.
-
I lean 'em, but I do few enough at a time to not need to stack 'em while leaning.
Otherwise, I do them flat in my drying cabinet, and don't see a problem with spotting, but we have good water (except that the drought has forced our company to augment their supply and it now has a distinct taste and smell.
We'll see if it changes anything in the screen cleaning and making process.
-
I lean 5 against the wall not stacking though. They stay there until the next 5 are reclaimed and then they go in the rack. The water is pretty hard here also.
-
Fanning them out on the floor letting only the corners touch
helps water from gathering. Clean floor of course.
-
4' 2*4 with 2*2 chunks as spacers screwed into it. Screen, 2*2, screen, 2*2, screen, ect. The 2*4 puts the screens at a nice angle for draining. The 2*2's slave them out nice, and as long as you insert the corner of the screens between the 2*2's, they provide enough support to keep them upright.
-
4' 2*4 with 2*2 chunks as spacers screwed into it. Screen, 2*2, screen, 2*2, screen, ect. The 2*4 puts the screens at a nice angle for draining. The 2*2's slave them out nice, and as long as you insert the corner of the screens between the 2*2's, they provide enough support to keep them upright.
can you post a pic?
Our biggest issue is space... when we're trying to dry 30-40 screens at a time it gets really tight in the screen room.
I might have to try the other Alex's recommendation of putting them in a rack on an angle... thinking I can modify one of my racks to just act as a drying rack.
-
Inspired by gkitson's racks http://www.theshirtboard.com/index.php/topic,13007.0.html (http://www.theshirtboard.com/index.php/topic,13007.0.html)
-
Inspired by gkitson's racks [url]http://www.theshirtboard.com/index.php/topic,13007.0.html[/url] ([url]http://www.theshirtboard.com/index.php/topic,13007.0.html[/url])
Greg uses those for post-exposure drying.. not for post-reclaim. Blowing dust onto your freshly cleaned screens seems to be a recipe for pinholes...
Plus, I wouldn't want water dripping from the top levels to the bottom.
-
I use the same racks for both, no issues at all. Each fan has a filter on top that I change when needed. The screens dry to the point of no drips within about 5 minutes, so as long as you are going left to right or right to left on both levels and start on the top, no drips. I haven't had a pinhole or snake eye since I started using it...
-
I do the same as Kitson's for post re-claim and to dry after exposure, and yeah dust is sometimes a problem so i use a lint roller before I coat screen's, only way your going to have perfect dust free screen is to have a nice clean room to store screens, which most of us don't have room for or a very nice cabinet.
-
I use the same racks for both, no issues at all. Each fan has a filter on top that I change when needed. The screens dry to the point of no drips within about 5 minutes, so as long as you are going left to right or right to left on both levels and start on the top, no drips. I haven't had a pinhole or snake eye since I started using it...
Missed the filter part :)
Might have to give this a try... at drip-free in 5 minutes, I can always rotate them through...
-
Every shop is going to be different, and this is probably more info than you need considering you are just asking about post reclaim drying. I have around 40 23x31 static screens in the shop currently, not counting things like super low mesh that I cycle just when needed, and my process for my larger sized screens varies (i have everything from 25x36 up to 58x46). I usually am doing 1-2 cycles a week right now, sometimes with small fill ins of 6 or 12 screens when I have a little down time and need a particular mesh count that I have already used up.
My basic setup:
I have a dirty sink and a clean sink. Dirty sink has my dip tank and two horizontal racks that hold 25 screens each. I put dirty screens in one rack right off the press, after taking off tape and carding off ink. Whenever I feel like it, I will cycle these through my dip tank that is filled with Supra. I only pressure wash off the emulsion and ink. These "half" reclaimed screens get put in the second rack and wait to be hit with 701 for dehaze/degrease. Once this rack is full, I fill in from top to bottom on the other rack until I have cycled all screens through the dip tank.
Whenever it is time for the second half of reclaim, I grab screens six at a time for dehaze/degrease. They basically go from the rack to the clean sink where they get a quick scrub on each size with 701, then leaned as a stack on the wall to the side of the sink. I then shift the stack around (i have a catch where I just lean them the other way so I can access the first screen I dehazed in the stack). This means the 701 has a few minutes to work its magic before pressure washing and soft rinsing. Once soft rinsed, I have a light positioned above the sink in a way where I can quickly see any sheen or irregularity in the mesh from drops or drips of the 701 that may not have gotten rinsed off fully. If it looks good, it gets put on the rack I linked. I pressure wash, rinse, and rack the remaining five screens in the stack. Then I repeat this for another stack of 6. By the time I am through with another stack, the first stack is drip free, though the mesh isn't always completely bone dry yet, which doesnt matter because I won't unrack them until another stack of 6 has gone through the process. Once I have 18 done, I usually find something else to do for 20 minutes or so, then unrack and stack in my screen room, which has a dehumidifier to get out any last residual moisture.
I have found that doing the dip tank throughout the week in 15-30 minutes here or there works the best for me, then batching the degrease/dehaze. Also, having the clean vs dirty sinks has helped enormously with snake eyes and dealing with random crud. I also noticed if I batch the dip tank and it has been a slow week where the ink has sat for a few days the haze is worse than doing it every day or two in smaller batches, so the cleanest screens come from getting it into the supra asap. Also, I know you are using the SP1400 just like I am, and I have noticed that the Supra is awesome for it, but if I use the 701 before dipping (like many suggest) it makes the supra less effective. I'm sure there is some reaction happening between the 701 and the SP1400 that is hardening it somehow, because it comes off like butter when I don't try to de-ink first, and the 701 takes care of any residual haze after the Supra without issue.
The only time my process varies is with waterbased screens, where I rinse the ink off using just water, and usually try to get them into the dip tank immediately since some of the pigments in the waterbased inks stain really fast (like red) if you let the screen dry at all.
-
What is the size of your sinks?
I have one big one, maybe two small sinks would be better.
-
one is about 48 wide x 30 deep and maybe 48 tall. I use that as the dirty sink. The other is 60 inches wide x 30 deep by 60 tall. I needed the large one to fit the larger screens I use for flags and all over prints. Bigger is better if you have the space. Less splash back for one...
-
Looked to make something on the cheap. 2x4s and cheap 1/2" pvc pipe for irrigation (not the Sch 40).
Build the frame and use a spade bit to bore the holes for the pipe to pass through the top and middle horizontal pieces, and just enough bored on the bottom to hold the pipe in place.
Cover the top with something to keep dust from falling straight down and you're good.
This one is in the corner of my office. I had it in my darkroom with my drying cabinet and exposure unit when I was in a warehouse and had more room.
-
clean compressed air. blast for about 45 seconds if you take your time... ready to coat in about half hour.
-
picked up a screen dryer at an auction about 20 years ago, best thing since sliced bread at the time...
Steve
-
picked up a screen dryer at an auction about 20 years ago, best thing since sliced bread at the time...
we have a vastex dryer, but I still get water spots if I put them in there... so vertical it has to be due to the hard water here.
-
we vacuum ours after reclaim/degrease and put them in a screen rack. We like to double-space them in the rack. It helps speed up drying. Then we wheel it into a 7'x7' drying room with a small 1000w heater w/fan and a MASSIVE industrial dehumidifier. The room varies between 105 and 120, usually lives around 10% RH. Screens are ready to coat in 15-20 minutes. Put back in after coating. Ready to mask in another 15-20 minutes.
We get random water spots that we cannot for the life of us figure out. Only on the 150-S. We tried drying more thoroughly, a bunch of different degreasers, etc. No dice. It's not constant. There is no pattern. Perhaps our water is hard...sometimes?
-
Perhaps our water is hard...sometimes?
Water quality absolutely changes throughout the year. A summer ago we had an algae bloom in our supply,
the water department notified everyone so it was at least obvious to me what the problem was when our
screens started going super wonky, likely from whatever they used to kill the algae.
-
We had no such issues with hard water when running out of our house, but there we were on a well, with a water softener...
we're planning on buying a building in 2 years or so... when that happens, I'll likely be installing a industrial-sized water softener/filtration system...
-J
-
If you have good filtered air and an air gun you can speed this up and eliminate the hard water issues. Spray white paper with your air gun and let it sit overnight to see if any oil spots form, these would be pinholes downline. We have a gun from Japan that I will glady offer up if you are willing to part with 200+ dollars that has a patented gizmo that spreads the air out to a 3-4 inch width to remove water on a 23x31 in about 20 seconds or less. You can do similarly with a typical air gun, just takes far longer. Drying off the frames, the creases, and mesh cuts the time to 1/4 of normal in a dryin gchamber. A heated closet/room/screen dryer is essential. On a rainy day with high humidity it can take an hour or more to completely dry the mesh. We cycle to coat in about 20 minutes from degrease depending on mesh count with this system. We have hard water here as well in LA, so getting all the water off before putting in a hot room with dehumidifdier (90F) helps prevent hard water circles or deposits. Vacuuming also works with the wide screen vacs, but they need to be kept clean and free of contaminants.
-
Al, do you dry screens horizontally or vertically?
Can we dry washed and coated screens in the same drying room?
-
Can we dry washed and coated screens in the same drying room?
We do. Sometimes on heavy flow days there are over 100 screens in there at a time. Some drying after reclaim, some after coating and some after developing. That's why I got the massive industrial dehumidifier. No problems so far...and it's been many many years.
-
Hello Maxie,
If you use compressed air to get off the majority of the water they can be dried horizontally or vertically. It has to be air that has gone through 2 sets of oil and water separators, one at the compressor and one set before the gun. I have found drying wet screens vertically introduces contamination from the crease between the mesh and frame. Hard water causes water deposits to form and air or vacuum removal really helps.
As far as storing reclaimed screens with coated screens, definitely not a good idea. Coated screens act like sponges and absorb the humidity from the air caused by wet screens, nearby devolping or reclaiming. If you must dry freshly coated screens with dry coated screens allow them to dry overnight to keep screens dry. Dehumidifiers can quickly keep air balanced but you need to have dehumidifiers large enough to dry bigger rooms. Keep sinks outside the room as well for this reason and use vapor barrier plastic sheets like they use in market cold rooms to keep water vapor from the sink outside the storage and exposure room. It helps to dry reclaimed screens in their own room with heat at 90-100Fand a dehumidifier and fans to rapidly circulate the air. The larger the room the better. Large air volumes (larger drying rooms) can hold more humidty and not jump in humidity levels like a small closet or DIY cabinet. Commercial dryers exhaust the air and do a great job of drying the screens. If yours has an exhaust vent run dryer ducting outside of the screen storage area if it is in the same room as screen storage.
I also recommend that coating be done before the shop closes for the night to make sure screens are free of any moisture before exposure and to allow as much drying time as possible. A moisture meter is the only way to know if dry coated screens are dry enough to shoot in cases where you must store reclaimed and freshly coated screens in the same room. (Not cheap, easier to just separate the processes into different rooms. Too many shops coat, check by hand to see if the surface is dry after only 30 minutes of dry time. The inside of the emulsion can be like jello and will not expose properly. If you print discharge you will see the screen break down sooner, often de-laminating from the screen. Exposure is inconsistent and the more you rush screens through the drying and exposure process, the sooner they will break down. Screen storage should be very dry, in the 35%-50% range.
All of this is dependent on ambient humidity. If you are in the tropics, a controlled dry storage area is a must, if you are in Las Vegas, Phoenix, or Israel, the ambient humidity is so low that you can dry faster, shoot sooner, and expose quicker and never need a de-humidifier. In winter a lot of the US is very dry when it is cold. Sometimes a humidifier is needed to increase ambient humidity prevent emulsion from cracking during production. A wall mounted hygrometer to measure humidity and temp helps create predictable exposures, (very inexpensive tool). Quite often exposure times are different in low vs high humidity on the same emulsion and the same exposure unit. Maintaining the room via air conditioning and a de-humidifiers year round can help my emulsion reach non stop production consistently everyday. In So-Cal it is normally perfect at 35%, but in winter when it rains exposure times can be slightly longer.
If anyone is coming to the ISS Dallas show next week I will be at booth 741 to talk shop.
We are testing a Starlight right now and will have times for all of our emulsions shortly.
Al
-
Can we dry washed and coated screens in the same drying room?
We do. Sometimes on heavy flow days there are over 100 screens in there at a time. Some drying after reclaim, some after coating and some after developing. That's why I got the massive industrial dehumidifier. No problems so far...and it's been many many years.
We do it as well. We use Grunig G-Dry 570 cabinet. All drying is done in it. We cycle through 50-60 Screens a day. We have no issues with screen quality. We added two small humidifiers in it to speed a process a bit.
-
After reclaim, I rack screens rotated 45 degrees, & angled downward from one rack level to the next...all excess water drips down from corner at back edge of rack, & has no affect on lower, (subsequently racked) screens