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screen printing => General Screen Printing => Topic started by: XG Print on November 27, 2012, 08:37:36 AM
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I have just finished our new screen closet which is not the biggest in the business but will work for us. I should be able to store at least 50 coated screens with plenty of room to spare for at least that number in stand by screens. My question is I am planning to run a small heater to keep the closet temp at a constant 85 degrees and I want to install a dehumidifier to pull the moisture out of the closet air. What should I set the humidity level at on the unit to achieve the best environment for drying coated screens. We normally try to reclaim and clean and coat screens in the afternoon before we leave so that we are good to go the next morning. Also, should I be storing my emulsion in a refrigerator. I have always stored it in the original container with the lid on and I try and put the gallon back in the box it came in and close the top. I have not run into any noticeable problems but was wondering if the fridge is better and I had seen some posts where people are using the fridge to keep the emulsion cool. Thanks
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A dehumidifier puts out a fair amount of heat, you may not need a heater. I have my dehumidifier set at 45%. I only store diazo emulsions in the refrigerator
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Set it for 35-45%. Like O said, may not need a heater.
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Sounds like. A nice start to a screen room. Keep it clean in there and mop the floor weekly.
Target sells small ceramic type heaters for $20 bucks this time of year. Combine that with dehumid running @ 40% and a small fan to create circulation and you should be golden.
Don't go above 100 in the room and no reason to put emulsion in fridge, just makes it thicker, ie viscosity goes way up and can make coating slow and difficult. Keep the fridge as a place to store your lunch and beer.
I know I know.. someone's gonna say I've been doing that for xx years and it works for me which I ask you, ok then why do you believe it needs to be in the fridge and who told you that?
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Remember to filter that air!
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I was thinking the same thing. We used to keep ours in the fridge, but then one day I asked why and I stopped. This was probably around 15 years ago.
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When your going through two to four gallons a month (which is piddly compared to the big guys) refrigerating emulsion is pointless. Just be smart and not store in your screen room or any where that gets brutally hot.
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My only input is I do not run my dehumidifier, when I have freshly coated screens, in the racks the fan in the dehumidifier stirs up dust, dust = pin holes.
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You should also install a bathroom exhaust fan in a corner of the ceiling. This will pull out moist air and helps the dehumidifier. One thing I never used in a screen room was a box fan.
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you can duct tape a/c fliters on any intake of any of the fans you use, reduce the amount of dust that can spread and in turn filter your room's air ;D
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many good points so far!
We run our dehumidifier at 40%, have a box fan to circulate the air (with one of those 20x20 air filters on the intake side).
'will also second not putting the emulsion in the fridge. Your best bet there would be to contact the manufacturer and see what they say. I would potentially go just the opposite and put the emulsion in the heated box so it is always the same temperature when you coat. This could help with consistency (if your room temperature is fluctuating now).
When you are getting the dehumidifier, make sure you get a hose to run the drain into a sink or something. We had to empty ours twice a day before hooking up the drain hose.
pierre
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you can duct tape a/c fliters on any intake of any of the fans you use, reduce the amount of dust that can spread and in turn filter your room's air ;D
yup, this is what we do! (minus the tape. fan is running 24/7 so the suction is holding the filter in place. Set it for low speed so you don't overload the motor).
pierre
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We're a little different. My screen department has something like nine different rooms all connected using special restaurant doors that minimize cross contamination. Each room has it's own temperature and relative humidity and all have industrial grade air filtrationj. More importantly they are swabbed down each night.
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A lot of this depends on your climate you already have.
If you are in an air conditioned or dry climate then the dehumidifier is just a bonus (and will generate plenty of heat). If you are in a humid area/shop then you don't want a bathroom exhaust fan on the room. You will basically ruin all the work that the dehumidifier is doing in that small space.
We are REALLY humid here and my cabinet is small (4x3x5'ish) and I don't get any water in my dehumidifier but I also don't vent the air... once it's dry in that cabinet it STAYS dry.
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My only input is I do not run my dehumidifier, when I have freshly coated screens, in the racks the fan in the dehumidifier stirs up dust, dust = pin holes.
Get a mop and clean your area up. No dust or dirt = no pin holes.
Best to keep the room sealed and don't use a ceiling fan as that means air out needs air in, ie your outside the room dirty air. Cirulate the air in the room and keep your dehumid running 24/7 with a drain line.
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Never suck air out, push filtered air in.
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Yup, John helped me a couple of years ago with this. Always over 80 degrees in there and always under 40 on the humidity. We get freaking cold up here and our warehouse is older so we just leave the heater on all the time in the screen room. We are knocking down walls / expanding / building in a few months and can't wait to redo our system. Multiple rooms connected like Tony was saying. And we don't fridge anything except beer and food
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I refrigerate my emulsion. If I don't in the summer it will go bad in a day (Arizona). I leave it in the fridge in the winter also. Why you may ask. Consistency, I know my emulsion is the same temp every time I coat my screens. It may not mater but if you can control a variable in the process why not.