plastic reusable filter paper/cloth

bio · Working Bee

If you ever saw the price of the teflon or polypropylene filter cloth then you will know why I'm looking for an alternative.

The polyester found in most cartridege filters has some severe resistance problems with some chems, even hot MeOH eats it up. Nylon is easy to find but it too has common chems that just destroy it in short order. Just found out that viscose is Rayon which is modified cellulose of some sort. Maybe I should check the fabric store for Rayon, anybody ever try this stuff. As regular lab paper is cellulose it might just be the ticket.

The teflon is of course the best but polypropylene is probably the best choice unless one has a $100 for a square foot of teflon.

Anyway after dismantling a few cartridges the media is either too porous or unidentified material that's a pain to test out. I've tried synthetic cleaning cloths/paper towels etc. and have yet to find what I need which is something close to 10-15 micron strong/thin polypropylene or polyethylene.

Any ideas out there?

IndoleAmine · Dreamreader Deluxe

Beer brewers use very fine filters to clean up the beer from the yeast and other garbage (ever wondered how they get "Heineken" beer that clear?)

Dunno about the prices though, but they have VERY small mesh diameters and are capable of filtering almost everything AFAIK. And about chemical resistance: these things can withstand at least dilute EtOH ( Laughing

), and further peracetic acid for sure - since this is what they clean them with... Wink

i_a

java · Consumer

I have used fritter glass funnels for years , as they can filter out almost anything and are reusable.......java

bio · Working Bee

Beer filter huh......probably in the grocery store in Canada. I'd guess they are very fine <2um if used for clarifying. I read somewhere that milk filters are very good as they will take oily emulsions w/o clogging. Never tried them though and no dairy around these parts. My favorite paper is Shark Skin as it's very strong and impervious to damn near everything.

I have a 90mm fritted buchner medium porosity but the damn things are a bitch to clean and that's too small for most things lately. Never tried the piranhaa solution but essentialy I quit using the thing for the gummy shit that clogs the pores as it is damn near impossible to remove. Been meaning to get some of the glass fiber filters one of these days.

On another subject that may interest many. The best place to get giant syringes and needles very reasonably is at your friendly neighborhood vet supply store. They make great pippettes.I noticed the other day at the one I usually go to that they had 100ml injection bottles of pentabarbital on the shelf next to the pet vitamins. I asked the owner what is this used for and he said anesthetic for surgery, how many do you want?

bio · Working Bee

Ok now, don't laugh too hard when you find out the possible solution to my dilema of the perfect, cheap, re-usable filter that stands up to almost everything a filter will ever be subjected to.

They are H.....s baby wipes in 100% FDA hypoallergenic polypropylene. Very Happy

Hope it doesn't take more cost of solvent to wash out the lotion and crap than real PP paper As an added bonus they have bromo-nitropropane add as one of about 15 other additives. Shocked

Wow, the stuff they wipe on babies! All the other brands had no label info on the fabris but quessing it's the same or maybe not as the aforementioned brand is damn near twice the price.

I really wouldn't be doing this nonsense if it didn't take weeks to get anything here in bwanaland. Last tube of silicone grease only took 6 weeks so it's used very sparingly. Come to think of it that 10 micron $93 sq ft PTFE paper might not be such a bad deal after all! Idea

bio · Working Bee

Don't know why I never noticed these before but they work great and are plenty sturdy.

Restaurant supply stores have them. What are they?

Cone filters for filtering HOT frying oil. Nice and big with sewn edges. The manufacturer even responded to my query! The ones I got are non-woven cellulose 53 micron rated and about a foot wide at the top. Tuff enough for the buchner after cut to fit and stand up to even 50% NaOH and everything else thrown into them so far.

meme · Wed May 04, 2005 10:05 am

Polypropylene is amazing stuff!!

Recycle code 5 in America.

It has many uses. Polypropylene "turkey" bags do not allow gas exchange and are a major weapon amoung cannabis smugglers. Polypropylene is also the ally to the amateur mycologist; since it can survive the 121 degrees of the pressure cooker, it is ofter used as a filter lid. Many mycology suppliers sell lids for this very purpose, but there is indeed a cheeper way.

Hypoallergenic pillowcases costing a few dollars are a great source of plypropylene. The USPS gives polypropylene away for free, in the form of envelopes, like the type used for t-shirts. This is a little too fine prolly for filtering, though.

Googleing "tyvek" should give you a host of other pp ideas.

Cellulose is easy too, OTC. Cotton is almost 100% cellulose. IT is impervious to organic solvents, although strong acids and bases will eat it up.

bio · Working Bee

He, he, he On my way to the pillowcase store.

Funny what's out there if one just looks hard enough. BTW the 100% PP babywipes are a little too absorbent and not very fine but are great for fast emulsion clearing!
They are the best yet for funnel plugs, drip steady and don't clog near as easy as cotton plugs. The more sheer PP restaraunt reusable washable wipes are good for plugs too but don't hold the shape when folded but flat on the buchner plate they stick real good and will gravity filter like this and much faster than a cone funnel.

IIRC Tyvek is PE with maybe a micron thin TFE coating designed to transmit vapors but not liquid. Seems would be good for gas filtering etc. Maybe you were thinking of TOPAR which is PP.

Cellulose of course stands up to damn near anything for a short time except for conc. sulfuric acid and a couple others. but who filters that anyway.

Now these frying oil filters have a water soluble resin binder less than 1% weight that hasn't caused any troubles so far but I can't find out what the hell it might be. Anyone have a clue on this? It could be the same stuff used on hardened lab filters, but really I don't know.

Also, has anyone out there tried the high dollar Teflon filter fabrics? Even my suppliers say they hardly ever sell them. No f.g wonder I told the salesman, look at this, you sure it's not a typo? He says well we'll give you a 50% discount on these instead your normal 20%. So I'm thinking about it if he'll break a package.
http://www.vwrsp.com/catalog/product/index.cgi?object_id=0008299&class_id=5003960

3um 203L x 254W P5PI001 28139-597 Pack of 25 $980.00

They are available in 5 & 10 micron also and that's mm not inches Indole so don't get excited. Shocked

Hiway robbery is all I can say and my old buddy Laura the saleslady left town, boo, hoo, hoo. She used to give me all the stuff the hospitals screwed up or didn't use etc. Like a case of 1,000 test tubes with one row on the end broken. and those disposable buchners that CAN'T be reused, damn the things were better than the non-disposable plastic ones.

bio · Working Bee

It's a breakthrough said old Joe when he came running over this morning! Abandon the baby wipes and help me fill out these patent forms.

I said WTF are you talking about and he waved the filter I made for him to try a few days ago. I've used it 12 times and it still is like new, he said.

Well Joe doesn't know that Dupont has probably already figured this out so patents on hold. Having been internetless for a couple weeks and having just finished an evil reduction one night bio decided to iron the wrinkles out of a big sheet of high dollar S&S hardened creped paper. This being the last sheet he decided what the hell; try it on some of those bargain brand orange cleaner PP wet wipes and low and behold the shit melted coating the iron with goopy plastic goo. The dollar store has packs of 50 for $1.11.

Lowering the heat the stuff shrank considerably and became stiff similar to good hardened lab paper. Hmmmmm now what if I try to stick a couple together? Walla!
2-4 sheets laminated will give a porosity good enough for anything I ever do and this stuff is indestructible.

Just find the setting were it starts to stick, somewhere between rayon and wool.. Then place between thin cotton and iron away using some pressure also. Holds a crease great if ironed in for making flutes for gravity filtering also.

loki · guinea pig

i've seen glass fibre filter paper before. I'd say it'd be moderately reusable and would definitely resist just about anything you could throw at it. Sintered glass is another option of course (but very expensive). Wool would be no good with alkali solutions as it readily hydrolyses and dissolves, but is probably fine for acidic solutions.

bio · Working Bee

Yea Loki; The glass paper is very good and would be reusable to some extent similar to the polymers if rinsed right away and generally used over only with the same type of stuff. At least that's what I do but take a look at the prices of the glass paper and weep!