microscopic glass beads?

[shoujin]

Looking for 20 micron glass beads.
Any ideas where to source?
The ones for road paint and sandblasting are a bit bigger.

[swamidog]

did you try here?

http://www.microspheres-nanospheres....lass/Glass.htm

[VDX]

... you can get a bag of sandblasting beads and sieve them.

I did this some time ago and separated them into "groups" <1µm / 5µm / 10-30µm / 50-75µm / 100-120µm / >150µm ... and even got some with 500µm and more diameter!

Viktor

[shoujin]

did you try here?

http://www.microspheres-nanospheres....lass/Glass.htm

No, I will email them. Thank you.

... you can get a bag of sandblasting beads and sieve them.

I did this some time ago and separated them into "groups" <1µm / 5µm / 10-30µm / 50-75µm / 100-120µm / >150µm ... and even got some with 500µm and more diameter!

Viktor

Thats clever.
But where did you find precision sieves?

I am experimenting with some DIY lcds and need them for spacers.

[VDX]

... I've got some etched steel foils with regular holes of 150, 100, 50 and 30 microns -- and etched some of my own for the smaller and uncommon separations

Viktor

[mixedgas]

UM balls may be a bad idea vs. rods. I spent a summer working in a LCD plant in college long ago.. There is a stage in making TN LCDs known as "Rubbing" where you buff a nearly invisible physical and static electric pattern into the spin-coated glass using a unloaded cloth buffing wheel. Typically this is at 45 degrees to the optical axis. This is to orient the LC fluid. If your doing the orientation step then you want rods, not balls as spacers. Because the rods will rotate with and or orient the fluid and the balls will not. The industry mostly uses rods for a reason.
~
My job was to run the buffer on evening shift before pulling a vacuum on the assembled glass plate pairs so the Thick fluid would diffuse in.
Filling was done in a low pressure chamber to get rid of bubbles. Please don't ask me any process questions as I don't know. I was not cleared to know about the process or materials used, I just showed up and spincoated the glass, baked it, then rubbed it using a rubbing machine. The day shift scribed the glass and glued it, then the night shift filled it.

Steve

[shoujin]

Thanks for sharing your knowledge.
I've read different articles on LCD manufacturing each describing usage of beads, rods or photo spacers. None mentioned the buffing step though.

[shoujin]

How do you mix the spacers and what is the ratio, if you are aware?
EDIT: Found the info in two separate chinese patents, it is "10% of the mass of the mixture".

[shoujin]

... you can get a bag of sandblasting beads and sieve them.

I just remembered I should have some glass sand for an old aquarium I had somewhere. Those should work too, right?

[VDX]

... it should be spherical ...