Novel Bioactive PEEK Composites Produced Using 3D Printing and Dry Powder Printing Technologies

Background and Aim: Bioactive materials like calcium phosphates areincorporated into Polyether-ether-ketone (PEEK) to improve the boneimplantinterface (bone apposition). The current manufacturing processeshave less control over the distribution of bioactive phase within the PEEKmatrix. In this research work, new techniques based on 3D printing anddry powder printing were developed for the fabrication of bioactivePEEK-based composites with the computer-controlled 3D interconnectedbioactive network within the PEEK matrix.Methods: Extrusion freeforming an extrusion-based 3D printer wasdesigned and set up for solvent-based extrusion freeforming of highresolution bioactive ceramic scaffolds. To make PEEK/HA composite,different bioactive HA scaffolds were made and over-molded with PEEKOPTIMA®LT3 UF powder. Dry powder printing (DPP) The developeddry powder printing contains two or more micro-feeders through whichparticles from several microns to a few millimeters could be co-fedaccurately. The use of ultrasonic vibrations aids in breaking arches ofparticles in the nozzle by applying a continuous force. Sub-millimeterrod-shaped PEEK-OPTIMA® granule and glass filler (porogen) were fedsimultaneously into a mold with the co-feeding system in different ratiosfor further heat treatment to prepare a homogeneous compound. Theblend could then be heated at 400ºC for 45 minutes to melt the PEEKand bond to the filler to create a PEEK compound suitable for machining into test samples.Results: Fig. 1 depicts SEM and CT images of vertical sections fromtypical PEEK/HA composite produced successfully through the optimizedcompression molding using static loading, and PEEK-HA interface (themagnified view). As seen, HA scaffolds are fully infiltrated by PEEK inboth vertical (infiltration depth is 3 mm) and lateral directions, whilemaintaining the HA network structure and uniformity. Images derivedfrom X-ray CT data (Fig. 2) were used to investigate distributions of mixedparticles with different size, shape and/or density of particles at differentlayers. The porous PEEK sample with narrow pore size distribution wasfabricated by this ultrasonic co-feeding method which has made asignificant improvement compared to traditional stir mixing.Conclusion: In this work, the use of extrusion-based 3D printing and drypowder printing technologies to make bioactive PEEK-based compositesis investigated. The produced composites provide new possibilities sothat biological and mechanical performance can be tailored.

کلیدواژه ها:

3D printing ، Bioceramics ، Bioactive PEEK composites ، Dry powder printing