About Measuring Tapped Density

By definition, The density of such a substance is called bulk density.It is a ratio of the weight of a unit volume of the loose material under testing or use to the weight of the same volume of water. If we take the actual definition of density, it should be mass divided by volume. The problem with this sort of direct measurement is that the volume of loose material is not the volume of the material only. It is the sum of particle volume, inter particle volume and internal pore volume, it is not a homogenous single volume and so the density of such a material is not an intrinsic property. It changes with how the material is handled. This is called the bulk density of a powder. Theseinterparticulate interactions affecting the bulking properties of powders, also affect their flow. Tapped density is measured in the same way as bulk density, and is the bulk density of the material after a compaction process like physically tapping the container. The bulk density, then measured will give a higher value than before. A comparison of bulk densities and tapped densities can give a measure of the relative importance of the interparticulate forces in a given powder. Granules are found commonly in minerals, pharmaceutical ingredients, chemical substances or foodstuffs. So one can gauge the relevance and importance of application of bulk density. It is indeed far reaching. Bulk density and tapped density are used in extensively in quality control, shipping and soil analysis. Bulk density and tapped densities are important powder flow properties and the deforming changes to the particles in a powder while subjecting it to flow movements in a powder rheometer (compressibility test) also affect the bulk density and tapped density of the material which can be observed by attaching a spectrometer to the remitter. Applications of tapped density and how it is measured When a powder is given the form of a tablet or capsule in pharmaceutical companies, or any other powder is given a particular shape for a purpose, tap test tool is required by scientists. The density, indexes and ratios of powders, granular and flaky material which are important for packaging and design of powder handling equipment are all calculated on these tap density testers at the push of a button. The material is filled in the tapping cylinder and initial measurements taken. It then undergoes mechanical shaking and rotation of the cylinder at the same time to ensure even packing of the powder sample. Protocol demands the validation at two tapping positions. The accompanying software generates reports and is quite user friendly usually. These testers comply to international standards. Who would imagine that the simple mechanical act of tapping a powder has so many implications?