Hi,
for my knowledge, there is no real intrinsic conductive polymer foil avaiable. There ICP like Pedot, polyanillin and others, but those need a matrix. You cannot integrate them into PETP which is used for films. Those are used for coatings.
I guess the stretch foil was made with additives, which are put into the raw material before melting the polymer. Those additives act on a certain principle.
The membrane acts like a reservoir, the additives migrate time by time to the outer surface and interact with humidity to provide conductivity. After a certain time the reservoir is empty conductivity gets lost.
Those foils are used in food industry, where shelf lime of some months is enough
Capaciti
for my knowledge, there is no real intrinsic conductive polymer foil avaiable. There ICP like Pedot, polyanillin and others, but those need a matrix. You cannot integrate them into PETP which is used for films. Those are used for coatings.
I guess the stretch foil was made with additives, which are put into the raw material before melting the polymer. Those additives act on a certain principle.
The membrane acts like a reservoir, the additives migrate time by time to the outer surface and interact with humidity to provide conductivity. After a certain time the reservoir is empty conductivity gets lost.
Those foils are used in food industry, where shelf lime of some months is enough
Capaciti
Yes, it's even stated on one the suppliers homepage.
About the film longevity "I know nothing", but I have two small stretch film speakers on each side of my computer monitor, built in November-05, still working.
I used the stretch film in a speaker where I could increase/decrease the tension, so I don't know how it behaves in a speaker with double sided tape as membrane mount.
One fine thing about this film was that u can use unpainted stator sheets, the thick film
seem to act as insulator between stators, very hard to get flash over!
One bad thing was that I had the feeling that it didn't not play as loud as ordinary coated mylar.
One fine thing about this film was that u can use unpainted stator sheets, the thick film
seem to act as insulator between stators, very hard to get flash over!
One bad thing was that I had the feeling that it didn't not play as loud as ordinary coated mylar.
i have been messing around with the pva glue trick it seems to be a viable altrenative.i made several differnt test samples it seemed to adhere well to the polyester type material(and some mylar) i used.the scratch test seemed as good as if not better than licron.it took quite a bit of force to mark it,only in a couple of spots did it rub of probaly due to finger print oils on the surface as with coating mylar, extreme cleaning is a must.i used 1:5 ratio split in 3 plastic dixie cups 1#plain 2#printer-ink 3#powdered-graphite.for some reason the aditives caused wetting problems so i added 1 1/2 drops or so of dish soap(dawn) and it seemed to correct the wetting problem.since my vom won't read any thing greater than 2megohms i decided to add more graphite to cup#3 and ended up with a high resistive conductive paint adding more graphite cuased more wetting issues and a couple more drops of dawn solved the problem.curious about the wetting issue, i made a new batch .this time i used 1:8 ratio and split it in two cups in cup#2 i put in 2or3 drops of dawn and promlem solved (see pics).i was able to get coating thicknesses of about .15mil or less, .2mil to .3mil or so on a double coat. using mixture #3 after heavily doping with graphite for the conductive experiment i swabed up some .1mil mylar scrap and using two dimes spaced 1/8" apart i am measuring between 200k to 500k or more as mileage varies, with a coating thickness that is barley mesurable.i will keep experimenting until i come up with a final mixture and have a product that is consistent.so far it looks very promising.but first, i have to get or build a meter that will measure 100megohms or more. mean while i will still build a new diagphram and test it.i will keep everyone posted on any new findings.jer
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Try to google something like static control products and/or dissipative coating - you well may discover quite a few coatings. Some of them are transparent. Pressurized spray can is not the best packaging either.
Alex
Try to use wide and short piece of coating to ease the measurement.
http://www.diyaudio.com/forums/plan...e-esl-completed-disappointed.html#post2067069
Adding soap as wetting agent is not OK - soap stays and collects dust as well as rendering adhesion unreliable at least plus wet soap conducts electricity - you do not need to add carbon...
Try degrasing using washing soda (sodium carbonate) instead, 8 per cent solution should work fine.
Use plastic/rubber gloves - it's mild irritant. Do not overdo.
Alex
Geraldfryjr.,
Your PVA coating is way too thick. I coated mine very lightly and the diaphragm stayed transparent with just a little change in color. There is no way that a multimeter can measure the resistance. I once did a measurement using a high voltage resistance meter, and I got a reading of around 50 Giga ohms per square. I like using black ink much better than graphite powder because when on the shelf, the solution has no deposit at the bottom.
Your PVA coating is way too thick. I coated mine very lightly and the diaphragm stayed transparent with just a little change in color. There is no way that a multimeter can measure the resistance. I once did a measurement using a high voltage resistance meter, and I got a reading of around 50 Giga ohms per square. I like using black ink much better than graphite powder because when on the shelf, the solution has no deposit at the bottom.
i yes i am aware and worried about using a soap as it was a very very small amount per liquid i used .any way im going to build a new frame and diagphram soon to try it.i am very impressed with the results i have so far.i have been using licron in the past and just wondered if anybody has used the new stuff it it supposed to be transparent.i ordered a sample and i hope they send it(for free) like the(orginal) last one.anyway i'll do some practice runs while i'm building some new spacer frames.yes i agree about the ink vs graphite issue.the ink i used is from a T0601 inkjet cartridge will that work? or should i high tail it to an art supply, if so what type and/or brand should i be looking for to use.jer
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Hi,
Jerald, if You need a lot of doping agent then there is something different with Your glue formula. Not every kind of PVA base material works! Instead of doping more and more You might try a different PVA. I gave the recipe which should work to Your confidence and only tiny drops of Ink are added.
I use a clear stuff and not the whitish ---ooh my god, Jeeerald, don´t tell us......keep Your hands off of Your........ *rotfloool*
jauu
Calvin
Jerald, if You need a lot of doping agent then there is something different with Your glue formula. Not every kind of PVA base material works! Instead of doping more and more You might try a different PVA. I gave the recipe which should work to Your confidence and only tiny drops of Ink are added.
I use a clear stuff and not the whitish ---ooh my god, Jeeerald, don´t tell us......keep Your hands off of Your........ *rotfloool*
jauu
Calvin
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ha ha ha,don't worry it's glue.im not aware of any other types besides white glue such a tightbond and elmers.elmers is what i used.i have yet to find tesa brand localy.im still seaching and will try whatever i find.some say elmers is pva ,some say it's not and some say it is but with additives.how ever it seemed to work.after my last post i did another test on some cleaned mylar with the ink solution and i had the same issues.the solution would just contract it self into a ball as in pic #5 .but buy using just enough dawn to coat an 1/8" of the tip of a toothpick was enough to cause it to form droplets on the surface of it's self.at that point i swabbed the mylar as lite as i could with a cotton q-tip swab and let it dry.i finaly rendered a coating i had problems measuring the thickness of(yeah!). so now i'm in the in the process of rebuilding my tiny driver(pics on materials for esl thread) and luckly a managed to get it apart without creasing the spacer frames.i'll keep you posted. jer p.s. it was just a quick test and wasn't strechted out on glass like it should have been.
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Checkout post #191 in this thread for my positive experience with Licron Crystal.
http://www.diyaudio.com/forums/planars-exotics/109789-esl-diaphragm-coating-20.html#post1942380
thanks bolserst!i have read most of this and somehow i had missed that section, though i do rember reading it not realizing that it was a new product.i'm hoping that a rep calls and sends a sample.however i would like more input if posible.because if they don't send one i may just order one anyway. jer
I have a can standing by, airbrush is on the way. Will post weight and R values. Long term?