Model Approach for Binder Selection in Binder Jetting

Three binders, polyvinyl alcohol (PVA), polyvinylpyrrolidone, and polyacrylic acid (PAA), are studied to elucidate the principal fundamental features giving rise to an excellent binder in a polymer–stainless-steel particle array, used in the context of binder jetting. Using an out-of-printer screening approach, samples were compared based on compression tests, specifically the 0.2% yield strength as a function of the void volume fill factor, ϕ, leading to a quasi-sigmoidal generalized curve for green body strength development. PVA demonstrated a strong tendency to form inter-particle bridges at low ϕ and the highest rise in strength, while PAA samples exhibited a lower tendency to form inter-particle bridges and a weak exponential rise in strength. This paper relates these behaviors to polymer strength, capillary properties, and polymer–metal interactions and ultimately provides a rigorous selection process for binder efficacy.