My Dry Fibers are Mixing. What Can I Do?

Don’t know your volume or fiber/powder specs, but a cement mixer could be used,...

for powders they use a pants leg mixer, this is a lab model, they make larger ones.

Good day.

I appreciate your suggestion...but not works..the fibers segregate.

It sounds like you may have to make the dry fibers, sand and powders airborne in the correct proportions in some sort of air conveying system and then allow them to mix in a cyclone air separator-collector to become the desired aggregate. From what you describe, bulk mixing is not going to work.

Not convinced: the purpose of a <...cyclone air separator...> is to increase the effective acceleration so as to make separation easier and quicker.

The Original Poster has concealed quantities and densities from the forum. There's not much to go on...

My thought process was three streams of air with the correct proportions of materials in each that are combined into a single air stream that then enter the air separator. I wasn't very clear on that in my first post.

The best I can do with the information provided.

Maybe you have a problem relating to different material density and the fiber surface is smooth enough to allow it to migrate to the surface.

This would especially be the case if the mixture is fluidized by air flow through it, allowing the powder and sand to settle and compact.

Maybe if you could get a rougher surface on the items they may stay mixed rather than separating.

Mix them SLOWLY to minimize separation.

We have not been provided with mass throughput, densities, grain sizes, fiber lengths, if the fibers are brittle, proportions, or if this is a one off or a recurring requirement. If large bulk and repeated use a gravity flow static mixer that rotates slowly about an axis of nominally 45^o to the vertical should be able to cope. The mixing occurs through a gentle cutting action so differences in densities and grain size and shape are not as critical as in a conventional drum mixer. The design of the internal mixing blades is a specialist skill so you need to contact a supplier/maker of static mixers. You to meter the ingredients in the correct proportions at the top end as three separate streams. The first set of blades cuts this into six streams, the second set into 12 streams and so on so you get 6, 12, 24, 48, 96, 192, 384, 768 etc. streams of material. The "Coefficient of Variation" (the degree of mixing) can be controlled accurately by defining how many sets of blades are fitted. When you contact the supplier, have all the information available and be prepared to supply ingredient samples and a sample of product ready mixed to your satisfaction so that the designer can supply blades to your requirements. They often have test labs where they will test and prove the blend before assembly of the mixer begins.

Bear in mind that this is a continuous process so you will need to install a method of keeping your metering stations topped up and bagging facilities capable of handling the throughput.

Good day.

Because of the "fiber nature," when those fibers came in contact they joined together, creating a lump (because it is too lightweight to go up the surface).

I will make a test with "static mixer" and SLOW rpm mixer.

Thank you.

Try blowing ionized air onto the fiber to remove any build up of surface charge. This should reduce it's tendency to clump together. Avoid using plastic when handling the fiber and operators should use earthed wrist bands and electrically conductive gloves if they need to hold it. For an automated system only pass it through earthed metal pipe work. (Google handling electronic components and combating electrostatic discharge)

Good day.

I thnk I do understand the electrostatic charge fenomenum...which I believe not happen in our case...because the fiber is cellulosic (could have a minor "charge").

No matter that I will make the test.

Thank you