Effective Length Scale for Predicting Solvent‐Debinding Times of Components Produced by Powder Injection Molding

The debinding of powder‐injection‐molded components is critical and time consuming, especially when the sizes of the powders used become relatively small (<5 µm). Mathematical relationships have been derived for predicting the polymer removal times for solvent‐, thermal‐, and wick‐debinding processes by considering one‐dimensional mass flow. However, the debinding of a component produced by powder injection molding occurs through all of its surfaces, and, hence, mass flow along all three dimensions needs to be considered. An effective length scale is introduced that considers the entire bulk of the component to compute the solvant‐debinding time and the wick‐debinding processes. The effective length scale is defined as the volume to surface area ratio of the compact. Introduction of this length scale in the existing equations successfully explains the debinding behavior of various geometries. Furthermore, the length scale helps us to understand the effect of the component's shape and dimensions on the critical heating rates for polymer burnout.