Investigating the effect of glass filler on the aging behavior of polymer powders for additive manufacturing

Powdered-polymer additive manufacturing processes, including selective laser sintering, high-speed sintering, and multijet fusion, have seen increasing usage throughout a range of industries, with corresponding requirements for better knowledge of material and component behavior. These processes involve the preheating, and subsequent selective melting, of consecutive layers of powder. Upon completion of the manufacturing process, unmelted powder can be recovered from the build chamber and, depending on its quality, reused for future part manufacture. Powder recovered in such a way can undergo a number of changes as a result of being held at elevated temperatures for extended times during the manufacturing process. Previous research has investigated these effects for polymer powders, with a particular emphasis on the most common polymer additive manufacturing powder, Nylon-12. In this work, we use a variety of characterization techniques, specifically size exclusion chromatography, differential scanning calorimetry, and rotational rheometry, to investigate this behavior for a glass-filled nylon-12 material, in order to identify any effects of the glass filler on material changes and on the properties of parts produced using these materials.