Powder Technology, Vol.306, 34-44, 2017
An experimental approach to powder-binder separation of feedstock
Powder-binder separation for a feedstock was investigated. A non-Newtonian viscosity model considering shear rate, temperature, and solids loading was employed to describe the rheological characteristics for a feedstock. The rheological parameters for the non-Newtonian viscosity model were obtained by torque and capillary rheometry experiments. The extracted feedstock in the designed jig, after injection through a capillary tube, was encapsulated in a mounting resin without pressure at room temperature to avoid destruction of the original powder distribution profile. The surface of the cross-section of the injected feedstock was polished with acetone to distinguish the powder from the binder. After the solids loading was measured in a radial direction by SEM, it was quantitatively calculated through image processing based on the intensity difference between the powder and binder. The ratio of the phenomenological coefficients, K-c/K-eta, for the steady-state solution was obtained by the mean residual method. The values of K-c and K-eta were determined using numerically and experimentally calculated convergence times. Based on the obtained values of the ratio of phenomenological coefficients, the powder-binder separation behavior in respect of the flux induced by shear rate, solids loading, and viscosity was numerically examined. (C) 2016 Elsevier B.V. All rights reserved.