The role of fine particles on compaction and tensile strength of pharmaceutical powders

Yohannes, Bereket; Gonzalez, Marcial; Abebe, Admassu; Sprockel, Omar; Nikfar, Faranak; Kang, Shuai; Cuitiño, Alberto M.

doi:10.1016/j.powtec.2015.01.035

Cited by 24 publications

(12 citation statements)

References 36 publications

(61 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These simulations reveal the evolution, up to relative densities close to one, of (i) mean mechanical coordination number, (ii) punch force and die-wall reaction, (iii) in-die elastic recovery, (iv) ejection pressure, (v) network of contact forces and granular fabric anisotropy, (vi) bonding surface area, (vii) Young's modulus and Poisson's ratio of the compacted solid. Our results are quantitatively similar to those experimentally observed in many pharmaceutical formulations [1,2,15,30,44,52,64,58,60,61,81]. Moreover, the evolution during compaction of these process variables (such as punch, die-wall and ejection pressures, and in-die elastic recovery) and compact attributes (such as Young's modulus and Poisson's ratio) is in remarkable agreement with the formulae reported in the literature-i.e., (semi-)empirical relationships developed over the last decades [20,26,27,53,54,58,60,74].…”

Section: Discussionsupporting

confidence: 89%

Generalized loading-unloading contact laws for elasto-plastic spheres with bonding strength

Gonzalez¹

2019

Journal of the Mechanics and Physics of Solids

View full text Add to dashboard Cite

We present generalized loading-unloading contact laws for elasto-plastic spheres with bonding strength. The proposed mechanistic contact laws are continuous at the onset of unloading by means of a regularization term, in the spirit of a cohesive zone model, that introduces a small and controllable error in the conditions for interparticle breakage. This continuity property is in sharp contrast with the behavior of standard mechanistic loading and unloading contact theories, which exhibit a discontinuity at the onset of unloading when particles form solid bridges during plastic deformation. The formulation depends on five material properties, namely two elastic properties (Young's modulus and Poisson's ratio), two plastic properties (a plastic stiffness and a power-law hardening exponent) and one fracture mechanics property (fracture toughness), and its predictions are in agreement with detailed finite-element simulations. The numerical robustness and efficiency of the proposed formulation are borne out by performing three-dimensional particle mechanics static calculations of microstructure evolution during the three most important steps of powder die-compaction, namely during compaction, unloading, and ejection. These simulations reveal the evolution, up to relative densities close to one, of microstructural features, process variables and compact mechanical attributes which are quantitatively similar to those experimentally observed and in remarkable agreement with the (semi-)empirical formulae reported in the literature.

show abstract

Section: Discussionsupporting

confidence: 89%

Generalized loading-unloading contact laws for elasto-plastic spheres with bonding strength

Gonzalez¹

2019

Journal of the Mechanics and Physics of Solids

View full text Add to dashboard Cite

show abstract

“…The functional dependency of these 5 GMA parameters with loading-path and macroscopic state variables remains elusive, but is of paramount importance for applying the GMA, informed by true mechanical and morphological properties of the granular system, to other general loading conditions. We believe the methodology presented in this work paves the way for addressing this challenge and, in turn, for exploring a large range of applications in various fields, including concrete [26][27][28], pharmaceutical [29][30][31], dentin adhesive [32], explosive and energetic [33,34] materials, which may favor from both detailed particle-scale mechanistic models but also from reduced-order models for manufacturing purposes [35].…”

Section: Discussionmentioning

confidence: 99%

Connecting discrete particle mechanics to continuum granular micromechanics: Anisotropic continuum properties under compaction

Poorsolhjouy

Gonzalez

2018

Mechanics Research Communications

View full text Add to dashboard Cite

A systematic and mechanistic connection between granular materials macroscopic and grain level behaviors is developed for monodisperse systems of spherical elastic particles under die compaction. The Granular Micromechanics Approach (GMA) with static assumption is used to derive the stiffness tensor of transversely isotropic materials, from the average behavior of particle-particle interactions in all different directions at the microscale. Two particle-scale directional density distribution functions, namely the directional distribution of a combined mechanogeometrical property and the directional distribution of a purely geometrical property, are proposed and parametrized by five independent parameters. Five independent components of the symmetrized tangent stiffness tensor are also determined from discrete particle mechanics (PMA) calculations of nine perturbations around points of the loading path. Finally, optimal values for these five GMA parameters were obtained by minimizing the error between PMA calculations and GMA closed-form predictions of stiffness tensor during the compaction process. The results show that GMA with static assumption is effective at capturing the anisotropic evolution of microstructure during loading, even without describing contacts independently but rather accounting for them in an average sense.

show abstract

“…Due to the straightforward measurement of relative density, which can be determined using Pycnometer and simple weight measurement with known volume, in addition to the volume change during compaction makes this approach attractive especially from the practical point of view. Similarly, Yohannes et al (2015) used relative density change in investigating compaction behavior of powders with different particle size distributions focusing on the role of fines. They report that fines do not affect the compressibility and strength past initial rearrangement state and therefore fines can be disregarded in computational modeling using discrete particle approach.…”

Section: Quality; Density and Density Distributionmentioning

confidence: 99%

“…Mechanical strength of powder compacts is one of most widely used quantitative metrics (Bonaccorsi and Proverbio, 2006;Hayashi et al, 2013;Krycer et al, 1983aKrycer et al, , 1983bMazel et al, 2014;Perez-Gandarillas et al, 2015;Russell et al, 2015;Yohannes et al, 2015). Compact's mechanical strength is influenced by many parameters including temperature (Rouèche et al, 2006) or properties of particle including particle size (Narayan and Hancock, 2005) in case of tensile strength.…”

Section: Quality: Strengthmentioning

confidence: 99%

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

Pandeya²,

Karamchandani

et al. 2018

KONA

View full text Add to dashboard Cite

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.

show abstract

The role of fine particles on compaction and tensile strength of pharmaceutical powders

Cited by 24 publications

References 36 publications

Generalized loading-unloading contact laws for elasto-plastic spheres with bonding strength

Generalized loading-unloading contact laws for elasto-plastic spheres with bonding strength

Connecting discrete particle mechanics to continuum granular micromechanics: Anisotropic continuum properties under compaction

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

Contact Info

Product

Resources

About