Your filters must be leaking/the fluid is going around. FWIW, you really can’t see anything smaller than 1 um without a microscope. Most bacteria are like .5 um and viruses are larger than .1
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So it had to have somehow managed to go around a 5u sintered disk, 1u killa disk.
Then I picked up 4 5u mesh gaskets from xtractordepot and put together a 3” filter cartridge just for these particles and it made it through that.
Seems odd.
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Anything smaller than 40 microns you cannot see with the naked eye usually.
I dunno what it is, but I doubt it’s felt particulate.
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I was thinking the same thing. If the particles are sub micron, how are they visible? It wasnt clear to me in the video what was being referred to as the particulate.
I dont think the felt is the problem here, but I’m biased obviously.
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How closely have you looked at them? Do you have a loupe or microscope? They look to be hauling ass through that solvent so they’d have to be pretty low density
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I actually tried to wash them out and it sat at the bottom of heptane and above water.
Also this issue was introduced after switching from celite to felt.
I do think depth filter style there is no singe at the bottom to acts as a catch. As the singe faces towards the spool walls.
Here is a jar of some (109g) diluted oil with no visible particles, passed through the depth filter. This murkiness came after going through the depth filter.
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How can you see sub micron particles though?
I mean .5 micron is way past what humans can see. We’re talking particles smaller than cells here.
Edited for clarity and dumb spelling.
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@Han
Can you get a particle of this isolated? If so lets try to look at under some magnification.
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Yup will isolate it today, need a day or two to grab a microscope
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Hi,
Awesome keep me posted, how many filters/ screened gaskets did that get through again?
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5u 6” sintered disk > 1u 6” sintered disk
Then for good measure 3 x 5u brand new mesh gaskets in a 3” spool
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ok. so neither through, nor around…
sesame street tells us we should still ought consider over or under, but imo we’re either looking at “they were IN the jar” or “they were formed IN the jar”.
they don’t look a lot like ppt to me…
edit: actually, they sort of do… “flocculant” seems almost appropriate.
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Just want to clarify, are you using the sintered disks that have an oring on the edge that fit down in the column, or are you using an actual welded sintered filter plate? I have had zero luck keeping particulate from coming through the disks which is why I use a filter plate, I was limited to different disks when I first started and I felt like I always had a little come through. If it passed through a 5 and then 1 um filter plate I’m going to have to start looking into this? Has anyone used the ulti filter from indofab? I have been looking for legit sub 1 micron filtration.
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if you add heat do the floaties disappear?
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I was wondering if it was something falling out of solution. If that’s the right term…
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from my experience any fiber in the solution should be visible to the naked eye. theyre easy to tell apart. if the floatie is translucent and shaped like a flake then its most likely something else falling out of solution
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so what do you see in the OP’s video?
yep. “falling out of solution” and “dropping out of solution” are both appropriate. more formal is “precipitating” (and some folks abbreviate “precipitate” to “ppt”). 
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its hard to tell if we can get a better video it would help. i would say he tries to add heat first to see if they redissolve. if its fibers from the felt they should not dissappear.
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We were thinking the cross section of the polyester fibers could be less than 1um, lengthwise they could be long enough to see?
Btw this was distillate in heptane pumped through a crc at 20 psi, The fibers starting showing up when he switched to using the felt. The screens will hold back mag sil, silica, and the clays no problem. It seems only the felt gets through.
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