Real-time product weight estimation based on internal pressure monitoring in injection molding

In this study, we investigate a novel method for determining product weight based on cavity pressure, measured by internal sensors integrated into the mold. The ultimate goal is to find a model that is better than the linear expressions in the literature based on the cavity pressure integral. We conducted experiments using different materials (ABS and PP) to assess the effects of holding pressure and time on product weight. The relationship between product weight, the pressure integral, and holding pressure was modeled with a saturation curve. This way, the maximum product weight achievable with holding pressure can be predicted. This method represents a significant advancement in quality control during injection molding, as product weight can be predicted within the production cycle before product ejection.