Determination of optimum production and 3D printer application temperatures for hemp fiber reinforced polycarbonate composites

Abstract This study delves into optimizing production parameters and 3D printing (3Dp) conditions for alkaline‐treated 10% hemp fiber‐reinforced polycarbonate (PC) composites. Initially, composite filaments were extruded at 250°C (PCH250) and 230°C (PCH230) to assess the impact of varying melt mixing temperatures on thermal behavior. Thermal characterization was conducted using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). DSC analysis indicated consistent glass transition temperatures (Tg) across pure PC and the composites, while TGA revealed minimal thermal degradation in PCH230 compared to pure PC. Subsequently, to ascertain the optimal 3D printing temperature, specimens were printed at temperatures elevated by 10°C relative to their melt mixing temperatures (PCH250/260 and PCH230/240), followed by mechanical evaluation via tensile testing. PCH230/240 exhibited superior mechanical properties, demonstrating a 12% increase in tensile strength and a 29% increase in Young's modulus compared to pure PC. Additional testing at 230°C printing temperature (PCH230/230) demonstrated enhanced mechanical strength over PCH250/260 but inferior performance relative to PCH230/240, attributed to incomplete interlayer adhesion observed through SEM analysis. Consequently, the optimal composite melt mixing temperature was determined to be 230°C, with an accompanying 3D printing temperature of 240°C for optimal mechanical performance. Highlights 3D printable, 5% NaOH treated hemp fiber reinforced polycarbonate composite. Printing composite with 3D printing device at different temperatures 230°C process temperature gives the best thermal properties. 240°C 3Dp temperature provides the best mechanical and morphological properties.