Clean Room in a Glove Box. - Page 1
Forum section: electronics / projects

author: JoeN
author_rank: Frequent Contributor
timestamp: November 13, 2016, 03:15:13 am
content: Obviously some things need to be done in a clean room, like hard drive repair. It seems it would be difficult to get a good quality clean room in your home lab. But it feels like it would be quite easy to do so in a glove box. If the box and the gloves are good quality plastic that doesn't outgas or create particulates, cleaning the interior of the box out should be easy. The box should have an "airlock" arrangement for introducing items into the clean environment and contain everything you need to work on that item. Now, how to replace the air to make sure there are no particles left? Any ideas on a good air filter setup and how well this arrangement would work? What would be the best materials for the box and gloves? Is this whole idea a good idea in general or have I missed something that makes this a terrible idea? Note, I see some things like this already on the web, but they are more for dangerous biological items with positive pressure or negative pressure, depending. All commercially available boxes are off-the-charts expensive. What I am talking about here is neutral pressure and just for electronics, but with as much particulate removal as possible from the air. Ideas? Thank you!Like this, but with a better airlock and an active fan/filter to maintain as close to zero particulates as possible (this box is over $1000 and without any positive or negative pressure or filtering!):

author: Rerouter
author_rank: Super Contributor
timestamp: November 13, 2016, 03:20:10 am
content: It would likely be a positive pressure enviroment being replaced by filtered air, that way no particulate can enter, and any that are introduced through the airlock collect at the leak points,I would imagine the next hardest part is getting the piece you will be introducing clean before it enters the environment, in a larger clean room, the object in question only adds a very small amount of dust per cubic meter, while in that enviroment, it would add quite a large amount,

author: JoeN
author_rank: Frequent Contributor
timestamp: November 13, 2016, 03:25:15 am
content: I had thought about that, but your response has helped me comprehend that problem even more. One thought I had was a double-lock system where you have two glove boxes like this connected and you introduce the work piece into the "semi-clean" box and use compressed air, wipes, whatever to get it extremely clean while obviously fouling the air. But you wait until the filtering system pulls that out and then you introduce the work piece into the "always-clean" box to work on it. I assume there will have to be some way to monitor the air and I haven't found that out yet, but it seems necessary to be able to judge when the air is clean enough to work on the work piece, and in this more complex arrangement, when the "semi-clean" box has cleaned up enough to pass the work piece into the "always-clean" box.My big assumption here is that the box or boxeswillget contaminated, but because of their small size, the filter will remove and replace the air at least every minute or so. The filter itself has to be very high quality because I want the return air to be as perfect as possible.

author: German_EE
author_rank: Super Contributor
timestamp: November 13, 2016, 03:32:22 pm
content: There are different grades of clean room and, depending on your needs, it gets more and more complicated.The simplest kind of clean room has operators in a cotton lab coat and before you enter you change your shoes then put on a hair net and gloves. The air is changed on a regular basis and this air is filtered before entry. As you walk in you pass over a sticky mat on the floor. That's it.Next step up. Proper clean room gear including hat, goggles, face mask, trouser coverings and covers over your shoes. The air is put through electrostatic as well as ordinary filters and you walk through an airlock that a) blows all the dust off you and b) maintains positive pressure inside.Full clean rooms have all of the above but the air is changed much more often and everyone who works there is paranoid about dust and contamination. The layout of the room is designed according to the desired airflow, walls, floors and ceilings are specially coated, the temperature and humidity are tightly controlled and nobody wears makeup or perfume. If you come back from a sunny vacation then expect to be banned for a few days until you stop shedding skin particles. Forget about working there if you have a cough or a cold.Note that a clean room is not just about dust, it's ALL contamination. This includes eliminating oils and greases from the area and monitoring your supplies to make sure that you don't introduce something that will increase the particle count. Open the wrong box of lab tissues and the paper dust could shut down your entire production process, scratch your nose with a gloved hand then handle a wafer and you could contaminate a million dollar piece of machinery.Now try and fit all of this into a box

author: JoeN
author_rank: Frequent Contributor
timestamp: November 13, 2016, 08:22:01 pm
content: Quote from: German_EE on November 13, 2016, 03:32:22 pmThat is a clever quote, but isn't the whole point that the box makes everything that you just said is hard a whole lot easier? How many people with perfume or a cold are going to fit into the box that I linked above? The box just took care of that problem because they are never in the box. No one needs to put on special attire or walk over a sticky pad before they enter the box because they aren't entering the box. Pig-Pen can use the box and get the same results as Charlie. If the box is airtight and made of material that doesn't outgass, you have solved a lot of the problems that are difficult to solve in a room. Replacing the air in the box regularly is easier. The equipment that will do that won't even be in the box, so the size of it does not matter. At least these are my thoughts on the idea.

author: jeroen79
author_rank: Frequent Contributor
timestamp: November 13, 2016, 09:01:17 pm
content: The small size could also be a drawback as you may not be able to keep as much tools and supplies at hand in the box as you could in a fullsized room.That could mean that you would have to move things in and out more often and possibly while you are working on something.Which would take more time and create more opportunities for a contamination.

author: edpalmer42
author_rank: Super Contributor
timestamp: November 13, 2016, 09:44:26 pm
content: I found this page with lots of good comments from people who appear to be knowledgeable in this area.http://www.iheartrobotics.com/2010/02/this-new-lab-diy-cleanroom.html

author: CM800
author_rank: Frequent Contributor
timestamp: November 13, 2016, 10:28:51 pm
content: You see some nice ones on ebay every so often, I saw a few back much cheaper and much larger then this one:http://www.ebay.co.uk/itm/Containment-Technologies-MIC-SINGLE-Chemo-Isolation-Glove-Box-Lab-Hood-nuaire-/172398394335?hash=item2823bebbdf:g:~hIAAOSwTA9X5BSOThat's all the good I could find right now, naturally it changes week to week.

author: macboy
author_rank: Super Contributor
timestamp: November 15, 2016, 03:43:04 pm
content: Looks very similar to a sandblasting cabinet. They usually run $100 and up, so don't break the bank. Maybe you could start with that and modify to your purpose...

author: rfeecs
author_rank: Frequent Contributor
timestamp: November 15, 2016, 03:59:27 pm
content: Another option would be a laminar flow hood. Looks like people have tried DIY versions.

author: RobertBG
author_rank: Regular Contributor
timestamp: November 15, 2016, 07:12:23 pm
content: We built one mainly for a small Sputter coater that was designed to work inside a glove box and while it took some time to get things running properly,it was definitely worthwhile compared to ready made options.Ours is a little bigger then a glove box but because we built our own it allows us to use the first chamber for other clean processes/uses.At times we'll even use it as a purge chamber for stuff like small ti welding etc,and we can even pull a vacuum on the first chamber by swapping out one panel.We did everything because we needed a clean space for cleaning,a vacuum/purge chamber and clean room/box for sputtering and had very little space for it all.So our first chamber is built like a bunker but for us it has other uses as I mentioned before.But I'd say if you have the need for a clean room/glove box you'll find uses for a 2 chamber setup even if you dont foresee them at the moment.Unless you have a immaculate work area.But we do composite work and no matter how clean we thought our office was it was never enough to even think of putting something inside a clean box.Thankfully the guys at EMS who sold us the gear talked some sense into us.Granted it led us down a rabbit hole designing our current setup to save space. Although we've been very happy with the results.While I doubt you'll need something like our primary chamber with multiple uses I'm sure you'll benefit from even the simplest of precleaning areas.I cant imagine doing most things in a glove box without one.If you want send me a PM and I'll send you a few pictures when get back in the States.I also forwarded this thread to the employee who designed everything.He's no longer with me,but we're still very good friends so hopefully he'll sign up and join in.

author: JoeN
author_rank: Frequent Contributor
timestamp: November 16, 2016, 01:52:23 am
content: Quote from: macboy on November 15, 2016, 03:43:04 pmI thought about that. I guess what I need to know more about, if anyone has any experience with this, is how to replace and filter the air and how to measure the level of particulates left. Obviously you will find out quickly how good that box is depending on how well the filter can do it's job. Any ideas on that?

author: JoeN
author_rank: Frequent Contributor
timestamp: November 17, 2016, 10:56:16 pm
content: That was more or less what I was going for, but I think something made out of acrylic sheets would be more permanent. My big question now is monitoring. Is there a reasonably cheap solution to tell you the number and size of particles in the air. How do you verify your solution works?OK, I found this. This is a place for me to start.http://www.ebay.com/sch/i.html?_nkw=particle+counterThese guys claim this is a 0.5 micron counter:http://www.dylosproducts.com/dcproairqumo.htmlThat could be "good enough"These seem to be much better, lab quality, but all the ones on eBay are used and relatively expensive and with no guarantees:http://www.ebay.com/itm/MET-ONE-227B-3-1-Handheld-Laser-Particle-Counter-/231975200490Older versions of the above technology that are cheap but not miniaturized. Plus side, they can be used as a boat anchor when they die:http://www.ebay.com/itm/Met-One-217A-204675-Laser-Particle-Counter-Analyzer-/112203945858