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.

The book concentrates on powder flow properties, their measurement and applications. These topics are explained starting from the interactions between individual particles up to the design of silos. A wide range of problems are discussed – such as flow obstructions, segregation, and vibrations. The goal is to provide a deeper understanding of the powder flow, and to show practical solutions.

Compaction of powder constituents-both active ingredient and excipients-is examined to ensure consistent and reproducible disintegration and dispersion profiles. Revised to reflect modern pharmaceutical compacting techniques, this second edition of Pharmaceutical Powder Compaction Technology guides pharmaceutical engineers, formulation scientists,

Powder flow has attracted increased attention in recent years as novel formulated and functional products are being developed in powder forms, particularly in pharmaceutical and high value additive manufacturing industries. This book meets a need for a truly integrated modern treatment of dry powder flow, covering theory, robust characterisation techniques, modelling tools and applications. Written by leaders in the field, the book opens by introducing the wide range of powder processing problems faced by industry, the complexities of powders and the myriad of ways their flow behaviour can be characterised. The authors then move on, with contributions from experts, to describe fundamental properties that can be measured, defining the states of stress and shear rate and the considerations that need to be taken account. By providing a comprehensive treatment of all available characterisation techniques, as well as various modelling tools, the reader obtains a clear, practical overview. Case studies and applications connect theory to practical examples across a broad range of industries. This book stands out by not only providing the reader with guidance on what to measure but also how to interpret results, ensuring this is an invaluable text for anyone working on powder flow in the chemical, pharmaceutical and manufacturing industries, as well as students and researchers across chemical and process engineering disciplines.

Handling of powders and bulk solids is a critical industrial technology across a broad spectrum of industries, from minerals processing to bulk and fine chemicals, and the food and pharmaceutical industries, yet is rarely found in the curricula of engineering or chemistry departments. With contributions from leading authors in their respective fields, Characterisation of Bulk Solids provides the reader with a sound understanding of the techniques, importance and application of particulate materials characterisation. It covers the fundamental characteristics of individual particles and bulk particulate materials, and includes discussion of a wide range of measurement techniques, and the use of material characteristics in design and industrial practice. The reader will then be in a better position to diagnose solids handling and processing problems in industry, and to deal with experts and equipment suppliers from an informed standpoint. Written for post-graduate engineers, chemical scientists and technologists at all stages of their industrial career, the book will also serve as an ideal primer in any of the specialist areas to inform further study.