Application Methods For Powder Compressibility

When the powder is put under any amount of pressure and weight, it tends to get compressed accordingly. The volume of powder is reduced in relation to the compression applied. The compression affects the flow of the powder. It obstructs the free flow and induces other feature in powder like a change in powder cohesion. It is still very tough to analyze the amount of compression to be applied upon the powder to maintain its natural composition. The method for applying powder compressibility depends upon many factors. Let's understand them one by one. 1. The powder cohesion – the articles of powder inherits natural cohesion or attraction between them. The smaller particles are packed closely and therefore attract and attach to each other closely. Whereas the larger particles are independent and flow easily. But other factors like gravitation affect the flow of powder. The internal friction and external friction with the channel wall could also affect the flow. The amount of compression would depend upon this cohesion. The more cohesive powder, the more perfect compression could take place. 2. Dynamic angle of repose – This is the steepest angle between 0 degrees and 90 degrees, which allows the powder to not fall from the side of the pile. Take the example of sand, when it is piled up freely without any external support making the small mountain, the angle of repose would be till the time it doesn't fall off from the side of the pileup mountain. The smaller powder particles usually have high stability, whereas large, coarse sand grain would easily slip off and therefore have the low angle of repose. The application of compression would be less on stable particles whereas it will increase with increasing instability and size of the powder particles. 3. Powder rheometer – It is an instrument to check the dynamic and bulk properties of the powder particle. It examines the shear strength, cohesion, internal angle of friction and specific energy of the particle. At the same time bulk density, permeability and compressibility of the powder. The compression amount could only be analyzed perfectly if we could extract the behavior of particles in throughout the process and powder rheometer facilitates that easily. It provides the overall data on powder characterization through which perfect compression could be applied. The powder compressibility is of utmost importance in powder processing. If it could be assessed properly, then the processing becomes easy and successful, but it goes wrong, then the whole processing shall need to be restarted. The compressibility of powder determines the weight, size and measurement of the final product. For example: in pharmaceutical industries where the powder is compressed to make tablet and capsules. Hence, the analysis and application of compression should be done precisely.