Foam additive manufacturing of thermoplastic polymers: The influence of the process parameters

The widespread adoption of foam additive manufacturing (FAM) in industries ranging from biomedical to aerospace hinges on the precise control of foam morphology, a capability not fully realized with current technologies. This study explores the potential of the FAM process, employing polylactic acid (PLA) and carbon dioxide (CO2) as a blowing agent, to finely tune the microstructural characteristics of foamed materials through controlled manipulation of process parameters. By systematically varying the pressure of the blowing agent, the time of absorption and desorption, extrusion temperature, speed, and nozzle diameter, we provide a detailed analysis of their individual and collective impact on foam morphology at both macroscopic and microscopic levels. Our findings reveal how specific parameter adjustments can significantly influence the density, diameter, and bubble size distribution within the foamed strands. These insights not only bridge a critical knowledge gap in FAM process optimization but also empower designers and engineers across various sectors to engineer foams with tailored properties for enhanced performance in lightweighting, insulation, and shock absorption applications. This research serves as a foundational guide for advancing the practical utility and scientific understanding of FAM technologies in producing next-generation foamed materials.