Segregation results when particles separate due to differences in their size, shape, or density. Segregation can result upon handling of a powder blend or material with varied particle size. Common segregation mechanisms include sifting, fluidization, and dusting.
Blending (or mixing) is the opposite behavior of segregation. The process of blending occurs when a collection of particles is homogenized or multiple ingredients are mixed to obtain a uniform product. Some materials require gentle tumble blending in a controlled batch mode while others require high shear to continuously blend highly cohesive and tough-to-mix ingredients. A well-blended material does not guarantee production of a quality product due to segregation effects that may result during powder flow.