(414g) Estimation and Explanation of Adhesive Mixing Efficiency Via Energy-Based Stick/Bounce Model

An energy-based stick/bounce model is presented to explain relationships between particle interactions dominated by Van-der-Waals force during mixing of fine and coarse particles at different mixing intensities. The investigation concerns examination of the adhesive mixing efficiency based on relative magnitudes of Van-der-Waals energy, dissipated energy, de-agglomeration energy and relative kinetic energy during impacts. indicates good adhesive mixing efficiency, while indicates poor adhesive mixing efficiency. Effect of size, material properties and mixing intensity of fine and coarse particles are investigated to attain a deep understanding of the mechanisms of adhesive mixing. Most interestingly, larger coarse particle size leads to larger agglomerate size of fine particles. Larger fine particle size and high intensity both lead to poor adhesive mixing efficiency. Size of fine particle agglomerates was also considered in the model. De-agglomeration energy was found to be highest amongst other energy terms during processing, indicating the de-agglomeration step was the most energy consuming step of adhesive mixing. The experimental results using a vibrational mixer and two sizes of fine (silica and cornstarch) and several sizes of coarse particles (KCl and cornstarch) validate the modeling as it explains various mechanisms. The guest silica particles tended to attach to the host KCl particles with a good adhesive mixing efficiency, while the guest cornstarch particles tended to detach from the host KCl particles beyond certain mixing intensity. Also, larger KCl particles would lead to the larger agglomerate size of cornstarch, indicating the poorer mixing efficiency. Finally, higher intensity leads to the worse mixing efficiency.