Obtaining excellent mechanical properties with additively manufactured short fiber reinforced polyether-ether-ketone thermoplastics through simultaneous vacuum and infrared heating

Additive manufacturing of short fiber reinforced thermoplastic composite with high-performance engineering thermoplastics is important in various industrial sectors because of their ability to manufacture complex and lightweight products. Although extensive studies in the literature are aimed at enhancing the mechanical performance of additively manufactured short fiber reinforced thermoplastics through methods like refining printing parameters, enhancing fiber fractions, and optimizing printing parameters, their mechanical performance remains limited. In this study, the individual effects of vacuum-assisted printing and infrared pre-heater-assisted printing and their combined effects were investigated to substantially increase the mechanical properties, interlaminar performance, and crystallinity ratios. The polyether ether ketone (PEEK) samples were printed with vacuum-assisted, infrared-assisted, and a combination of vacuum and infrared-assisted environments were subjected to three-point bending tests to evaluate their mechanical properties. Synergistic vacuum and infrared-assisted printing significantly enhanced the mechanical properties as the flexural strength increased by 54.58 % compared to printing under vacuum alone. Moreover, the flexural strength and elasticity modulus of samples printed with vacuum-infrared-assisted manufacturing increased by 324.48 % and 239.77 %, respectively, when compared to printing under atmospheric pressure without additional heating. Thermal and structural characterizations of the printed parts revealed that this significant improvement was attributed to reduced porosity ratios and increased crystallinity.