On the Tertiary Recycling of PVDF Composite Matrix by 3D Dispenser Printing

Several studies have reported the mechanical and sensing properties of polyvinylidene fluoride (PVDF) composite matrix as dry cell components with the material extrusion (MEX) process for ensuring tertiary (3°) recycling. However, little has been reported on 3D dispenser printing of PVDF reinforced with NH₄Cl to ensure better recyclability and acceptable mechanical and sensing capabilities. This study used 3D dispenser printing of PVDF reinforced with NH₄Cl to ensure its 3° recycling for possible use as a dry cell component. The mechanical and sensing capabilities of 3D dispenser printing-based functional prototypes of PVDF-30% NH₄Cl were compared with the MEX process. The sensing parameters in terms of dielectric constant (ε_r), reverse transmission (S₂₁), and reflection coefficient (S₁₁) were noticed and tuned as per the industrial scientific and medical (ISM) band. The results suggest that the 3° recycling of PVDF composite matrix by 3D dispenser printing resulted in a ε_r of 9.03 in comparison to the ε_r of 2.09 processed by the MEX process, which significantly contributes to narrowing the bandwidth of a fabricated sensor for condition monitoring applications. Regarding mechanical properties, the change in Young's modulus (E) and crystallinity % was found insignificant for the selected PVDF composite with the MEX and 3D dispenser printing.