Many of us use coffee filters for filtering larger particles and other instances. I'm trying to find some other materials which can be used which may
be better.
I'd like to be able to flute the paper so it needs to be thicker. Fluting the paper allows for faster filtering by keeping the paper from touching
the side of the funnel (which blocks the flow a good bit).
I've used paper towels from ones like Bounty (fluffy/thick store bought) to thin towels that are more paper-like that are found in institutions like
schools, gyms, gas stations, etc - they are inexpensive and the remaining rolls are often discarded with 1-3" left on the roll. These thinner towels
block smaller particles than coffee filters but they do tend to rip more easily.
I'm wondering if there are any commonly available materials that work well as filter paper, possibly art supplies like drawing paper or similar.
Does anyone know of something that would work well, especially something that may be a little thicker (to keep liquid pressure from pressing paper
against funnel side when filled)?
Melgar - 24-5-2017 at 14:11
This may be stating the obvious, but when I don't have proper filter paper, I'll either use cotton fabric, or filter through a cotton ball. Old
t-shirts work okay, if they're clean and not too worn out. Old bedsheets and pillowcases (woven cotton fabric) work better. The only annoying thing
is that I usually get dark-colored bedsheets so they don't look dingy as quickly, and dark colored filters aren't ideal.
I'm kind of spoiled in that respect though. I work in the garment district area in NYC, and find piles of fabric scraps on the curb all the time.
And if I don't want to use that, the jewelers' supply store has some of the best filter paper there is, for pretty cheap. It's used for collecting
precious metal dust by jewelry polishers, so it HAS to be good.Ozone - 24-5-2017 at 15:49
Coffee filters. You can stack several of the "basket" sort, or use the conical ones. The latter are thicker and have a tighter weave.
O3Dr.Bob - 24-5-2017 at 16:36
I have some fluted lab filter paper, as well as large sheets (about 17 x 11") of filter paper. It is a bit bulky to store, so I am happy to sell it
cheap. I think the pre-fluted ones come in small, med and large, which are pretty much about 3" dia, 5" (see below), and 7" roughly. Or I can just
fill a bag with assorted pieces. There is also some selling on Ebay, the prices are not bad on the one below, but I am happy to match or beat them,
especially if you buy a few items.
Pharmacies sell "cotton rounds", for removing makeup & other facial cleaning uses; they're flat circular discs which fit conveniently into my
Buchner funnel:
Old (washed) cotton t-shirt cloth is good for straining vegetable matter.
My current filtering nemesis is yeast from fermentation. phlogiston - 25-5-2017 at 13:42
A layer of clean sand makes a pretty effective and cheap filter for removing small particles.
Make sure to wash the sand with acid if you need to filter acidic liquids though.
Another effective method to remove small particles is centrifugation. Magpie - 25-5-2017 at 13:54
Old nylon stockings work wonderfully for straining old paint. I've never tried them in my lab, however.Melgar - 25-5-2017 at 19:41
Old nylon stockings work wonderfully for straining old paint. I've never tried them in my lab, however.
As a polyamide, I'd expect nylon to be disintegrated by acids and bases of moderate strength. Polyester, I'd expect to hold up better. That's the
same thing that PET bottles are made of, and the only things that seem to damage that are saturated alkali hydroxide solutions and concentrated H2SO4.
(And probably nitric acid too, but I was never dumb enough to try it)Atrum - 26-5-2017 at 11:15
