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Sooner or later, every math instructor is left with stacks and stacks of transparency sheets covered head-to-toe in Vis-a-vis scribbles of sigmas and circumferences, of radicals and radii. While the process for cleaning them is simple, involving just time with a spray bottle and paper towel, the task
is time consuming, especially with accelerated math teachers, who have classes full of nerds and no detention hall students to shift the burden to.
So, would it not be too difficult to build a small device, which would feed a used sheet through, and return a clean, dry sheet ready for re-use? Diffrent methods of cleaning could be used:
1) Pool of water and brush
As the transparency sheet moves through a pool of recirculated water, filtered and replaced often, a brush wipes off any stubborn marks. Requires frequent brush changing.
2) Pool of rapidly moving water
As the transparecy moves through rapidly moving water, the markings are removed.
3) Ultrasonic cleaner
The transparency moves through a pool of water agitated by a ceramic ultrasonic chip, like the ones used in optics cleaning.
All of these methods could work, but would require a means of filtering and recirculating the water, etc. However, most work with it would be done as a batch job.
Could also take long, continuous 'scroll' sheets for overheads with rollers.
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As long as it's multiple choice I'll choose 4) All of the above. |
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I imagine something like the old electric washtubs with a roller above a ramp that lets the squeezed water flow back into the tub. something the teacher could take into the bathroom (or find the hapless detentioner to do this), and do it in a sink. there would be the portable versiion, like I mentioned above, and the delux "department level" model. |
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No, this is serious. I'm a first year teacher with two inches of transparencies that I would like to recycle. |
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Allow it to print vis-a-vis via ipod? [+] |
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Weird as this is, I’m an engineering student and my current project involves prototyping this exact device. I stumbled across the halfbakery whilst doing some market research (not that there is any market at the moment, I’m comparing my initial ideas with record and CD cleaners!). Currently I'm focusing on a device to clean the transparency scrolls which are still used in the physics department at my college. The lab technician here has to every year, laboriously wash the scrolls by hand and hang them out to dry (he he!) Below are the main points from my client brief: |
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The machine would have to:
• Be safe to use in school (comply with legislation)
• Transportable
• Be not so big to fit over the sink if the need be
• Have a rewind / fast forward function
• Be speed controllable
• Have a drying function
• Be adjustable to accommodate A4 and A3 scroll sizes |
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I had started with the simple idea of passing the scroll through rollers arranged to give a U shape so that I could pass the bottom of the U through running water and a reciprocating scrubber. I am thinking of using a stepper motor to control the movement of the scrolls like in a sophisticated tape recorder. The Ultrasound idea also sounds quite promising. |
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If any of you have any input or have used these transparencies and just want to have a say about where you’ve used them, if you think having a automated scroll cleaner is a good idea, and any functions that you think should be included, Then anything would be very much appreciated to help with my market research. |
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As a math teacher myself, you have just ruined my attempt to an early retirement. I have had this on my mind for two years now and just don't know where to begin. You have no idea how annoying it is to clean these puppies (even though students (young ones) drop everything to help you). It would sell HUGE in schools, so i know that marketing would not be a problem. I don't know the science behind it, but it seems like it wouldn't be too difficult to construct.
However, Mechwacko..you talk about a cleaner for the transparencies on a roll, what about the single sheets...those are more commonly used. Thanks, |
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I think transparancies of either sort could be cleaned by prolonged immersion in hot soapy water, perhaps with gentle agitation. [school23], just fill your cooler with water, add some dishwashing detergent, dump in your transparencies and leave them. |
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Thanks guys for the input! I am currently looking at using a series of paint rollers to build the prototype. The transparency is pulled through by an electric motor and then passed between paint rollers which can be rotated to brush against the transparency manually. I had the idea of drying the scroll by passing it through a drying agent such as ethanol or propanone, wiping the roll dry with a rubber wiper and then drying with a fan. This is getting a bit more complicated now… |
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I recognise school23’s point that A4 transparency sheets are also very common and is something that I will have a look into and re-consider. I guess it would be more difficult to clean a lot of A4 sheets unless they were fed in automatically similar to how an inkjet printer loads paper. I spoke to the lab technician who has to clean the scrolls and she is determined that I shall produce something that scrubs the scroll automatically. I went to see her the other day and found that she had informed all the technicians at the site of my “project”. Anyway they all seemed very excited about it, lol :) |
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I think the cleaning of the transparencies is not really the main problem. I find that they all come clean by just running a little water over them. The problem is that it takes forever to hand dry 30 transparencies, and then there is the problem of space to lay them out if they are not completely dry. |
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Jesus. So your education department is too cheap to buy you a pc and a litepro as well? I mean that's why MS Powerpoint was made. |
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//I mean that's why MS Powerpoint was made//
Yes, the $200 piece of software to complement the $1000 laptop and the $4000 projector, to make the $.50 piece of plastic paper obsolete. |
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where this is really needed is on the reel to reel OHP's. who is going to clean a semester's worth of lecture off of a 100ft roll? if you could crank it through a set of rollers and reuse it..... nostalgia I'm afraid. |
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The water used for cleaning these will eventually contain all the ink from the transparency sheets, and should therefore be boiled down and used to refill the pens. |
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But how would you separate the colors? Maybe
chromatography? |
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Anyway, I have an idea coming up whose mechanism might
be quite adaptable to transparency cleaning, in case
anybody still has that need. |
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Anything is possible; do you have any similar ideas, like a quicker way to de-fluff a Spinning Jenny, or a better design for a chariot harness ? |
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