Thermal Simulation and Warping Deformation Experimental Study of PEEK in Material Extrusion

Abstract

Ceramic materials, including alumina and zirconium oxide are mainly formed by 3D printing (3DP) and sintering. [8,9] However, this technique results in up to 40% volume shrinkage in the model and finding an appropriate binder is an enormous challenge. [10] Recently, polyether-ether-ketone (PEEK) has been proposed as a dental implant material. Studies have shown that PEEK is a semicrystalline thermoplastic with a melting point of 343 °C and a glass transition temperature of 143 °C. It has beige appearance, reasonable dimensional stability, outstanding biocompatibility, and excellent mechanical properties. [11] Moreover, it transmits X-rays. [12] Its elastic modulus is close to that of the cortical bone, which can reduce the stress shielding after implantation. [12,13] Therefore, it is an effective material to replace conventional implant materials. It is worth noting that complex parts can be quickly manufactured through the material extrusion (MEX) method. However, it is difficult to produce ideal PEEK parts using MEX. Literature review has indicated that many scholars have studied the warping deformation of parts printed by the MEX technology. Zhang et al. [14] established a mathematical model for calculating the amount of warping deformation of parts. They observed that increasing the printing speed and reducing the layer thickness can reduce the warping deformation of the printed parts. Wu et al. [15] explored the effect of the molding chamber temperature and nozzle temperature on the warping deformation of printed PEEK samples using the single factor method. Their results showed that the warping deformation is minimal when the temperatures of the chamber and nozzle are set to 130 and 350 °C, respectively. Lv et al. [16] designed a heating baseplate that can achieve temperature compensation, thereby increasing the heat at the boundary of the baseplate. Therefore, the warping deformation of parts can be effectively reduced. Liu et al. conducted experiments and studied effects of the printing speed and nozzle temperature on the warping deformation of polylactic acid specimens printed by the MEX method. [17] Furthermore, studies have shown that, compared to the experimental method, the finite element method is more economical and effective in the optimization of the process parameters. [18] Ni and Song studied the temperature and stress fields of acrylonitrile butadiene styrene specimens produced by MEX. They pointed out that the warpage deformation could be Polyether-ether-ketone (PEEK) is a high-performance biomaterial, which can be used to fabricate dentures, mandible, and other human implants. However, when the material extrusion (MEX) method is employed to print parts using PEEK material, the parts are prone to warpage deformation, which affects the fabrication quality of PEEK parts. Moreover, the uneven temperature field adversely affects the crystallization of PEEK, causing the printed objects with hazel appearance which affects the beauty of the denture. In this paper, finite element analysis is initially...

Research on the Fused Deposition Modeling of Polyether Ether Ketone

“…This is because, as nozzle temperature increases, the residual stress decreases, resulting in a decrease in warpage. However, a higher nozzle temperature could lead a higher temperature difference between extruded filament and printing chamber, which will result in a larger thermal gradient in the samples [ 54 ]. Therefore, it can be seen that, as the temperature increases, the tendency of warpage to decrease gradually slows down.…”

Numerical Study of Residual Stresses Due to External Cooling in Extruded Polymer Profiles

“…Stress-relieving techniques were suggested in literature to enhance the quality of the final product. Han et al [29] numerically studied the effect of different processing parameters on the temperature and stress distributions of PEEK during the extrusion process. They found that uneven temperature and stress distributions in the material enhanced warping deformation.…”