Disperse – distribute or spread over a wide area.

That is the root of the word dispersion and is a simple explanation of the term. Particle dispersion refers to a homogeneous blend of particles suspended in a liquid. The process of dispersion involves understanding particle size, surface area, processing equipment, and use of raw materials.

When mixing a solid with a liquid the solids have a tendency to clump together. These large groupings of particles can create an uneven dispersion in the liquid. You may not be able to simply just look at the materials and see the large clumps because they are still small. If you run them through a particle analyzer you will be able to get results of what your particles sizes are. Depending on the range the particles are in you will be able to verify that the grouping of particles may still be too large.

To better understand how dispersion works here is an example:

  • If you take a cluster of grapes that are closely nestled together with various sides touching each other, you have areas that are not exposed to the surrounding environment. Take several clusters of grapes and spread them out so they do not touch. Now as you pick the grapes off the vine and spread them out so they are not touching any other grape the large areas between the clusters begin to fill.

Take that cluster theory and apply it to a cluster of particles known as agglomerates suspended in a liquid. If they are all grouped together in clumps in the liquid you would see an uneven pattern. Now break them apart to expose the individual particles surface area to the liquid a more consistent pattern will start to form. If you examine it under a microscope you will see a better overall area coverage. The broken down particles in the liquid will create a homogeneous blend that is known as dispersion.

To get the particles to break apart there is specially designed equipment, known as dispersers or mixers that can break down particles and disperse them in a liquid medium. Some equipment is fitted with circular flat blades attached to the end of a shaft that have teeth around the edges. As the liquid flows over the blade and teeth, the particles come in contact with the areas and break apart.

What are the benefits to better dispersion?

  • Products like paint have better smoother coverage.
  • Longer lasting materials
  • Materials are more durable to the surrounding environments
  • Better vibrancy in colors
  • Increase performance level of the product

Disperser and mixers and only break down the particles to certain sizes, to achieve even smaller sizes Custom Milling & Consulting, Inc. manufacture’s media mills. They specialize in building dispersion equipment and understand everything that goes with processing wet materials. Contact us at sales@cmcmilling.com to find out more of what they can do for you.