Flow and Compaction Behaviour of Powders with Deep Grooved Punches

Download or read book Flow and Compaction Behaviour of Powders with Deep Grooved Punches written by Gweni Alonso Aruffo and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of compacts with complex geometries by means of powder die compaction can be a delicate task. The compression process, used in many industrial sectors, is based on the densification of a powder bed by the application of an external load to obtain compacts. In some situations, the presence of defects (for example, cracks) in the compacts can be observed following the compression process. These lead to the degradation of the mechanical properties of the compacts and therefore their properties of use, thus leading to the non-conformity of the sample. Defects in powder compacts can be mainly due to the homogeneity of the compact, the mechanical behaviour of the powder and the complexity of the geometric shape of the sample. The work of this thesis contributes to the analysis of the compaction of pharmaceutical powders on large compacts with complex geometry (presence of grooves). In particular, to further understand the impact of the geometry of the compression tools on the final state of the compacts, both experimental and numerical studies were carried out. In order to model the mechanical response of the powder in compression to an external load, the Drucker Prager Cap (DPC) model was employed. To overcome a scaling problem, a hybrid calibration method of the DPC model was introduced in this work to provide a more realistic prediction of the powder behaviour in compression. The numerical results obtained by finite element simulation were validated by means of tomographic analysis.