Critical Review on Engineering Mechanical Quality of Green Compacts using Powder Properties

Abstract

For processes involving particulate materials, mechanical properties of green compacts are of great interest when they are final or intermediate products. Optimal quality of green compacts is achieved usually with empirical approaches, i.e., unexpected issues in processes or products' quality are usually mitigated by time and resource consuming trial-and-error methods. Issues of the powder compaction are commonly observed when there are problems in feed materials or operational conditions even without any substantial change in a formula. Such divergent behavior of particulate materials is especially problematic for product developments and reliable operations. It has been widely accepted hypothesis that properties of particles are determinants of mechanical behavior of powder during compaction and the quality of resulting compacts. With recent developments in nanotechnology, characterization and engineering of individual particles at a microscopic or sub-microscopic scale are now feasible. Leveraging recent technological advancements, there has been a good progress in regard to quantitative understanding of mechanical relationships between properties of particles, particle system and final product. This review highlights the recent developments and gaps in engineering mechanical quality of powder compacts in conjunction with the characterization of particle systems and compaction at multiple scales.

Loading-unloading contact law for micro-crystalline cellulose particles under large deformations

“…Therefore, the work presented in this paper, in combination with these detailed calculations, can contribute to develop microstructure-mediated process-structure-property-performance interrelationships and, thus, to establish the relationship between particle-level material properties and tablet performance. Ultimately, these relationships are needed to assist QbD and QbC product development and process control (Yi et al, 2018).…”

“…These strategies are further complemented by Quality by Control (QbC) (Su et al, 2018b) techniques, which are more prevalent in the continuous manufacturing practices as they provide increased flexibility to the design space and efficiency in characterization processes (Su et al, 2017(Su et al, , 2018a. Understanding the connection between mechanical behavior of a single particle and tabletability of the powder, i.e., the ability of the powder to gain strength under confined pressure, is essential for realizing QbD and QbC objectives (Šimek et al, 2017;Yi et al, 2018). An alternative approach utilizing empirical models has been extensively attempted, albeit with limited success, to try to capture the stress-strain relationship of a powder bed under load.…”

“…Understanding the connection between mechanical behavior of a single particle and tabletability of the powder, i.e., the ability of the powder to gain strength under confined pressure, is essential for realizing QbD and QbC objectives ( Šimek et al, 2017;Yi et al, 2018). An alternative approach utilizing empirical models has been extensively attempted, albeit with limited success, to try to capture the stress-strain relationship of a powder bed under load.…”