Experimental study and numerical simulation for the interaction between laser and PEEK with different crystallinity

Abstract

Polyetheretherketone (PEEK) sheets with the thickness of 0.5 mm were prepared by compression molding process using Victrex PEEK-450PF, and then PEEK sheets with different crystallinities were obtained by controlling the cooling rate. The optical characteristics of the samples were respectively measured by laser power meter, UV-VIS-IR spectrophotometer. And with the process parameters of laser power density of 245 W/cm2 and moving speed of 5 mm/s, the effect of crystallinity on the laser energy absorption of PEEK and the influence of laser irradiation on the crystallization properties of PEEK sheets were systematically studied. Finally, numerical model of laser energy absorption by PEEK was constructed with COMSOL software. The results show that the reflectivity of PEEK will increase with the increase of crystallinity, while the transmittance decreases. The pure PEEK sheets do not strongly absorb the laser at the wavelength of 1070 nm and the amorphous PEEK is more likely to be ablated. Carbonized samples during the laser irradiation was taken for XRD test and found to be amorphous. After laser irradiation, the crystallinity of the semi-crystalline PEEK material will decrease, but the originally amorphous peek crystallinity will increase slightly. Besides, the numerical simulation results are in good agreement with the experimental results.

Femtosecond laser optimization of PEEK: efficient bioactivity achieved by synergistic surface chemistry and structures

“…This meant that the laser treatment made the crystallinity of semi-crystalline PEEK drop significantly, which was primarily due to the fact that the high-energy laser beam brought the temperature in the action area rising sharply in an instant, then cooled down rapidly, which was similar to a quenching process for PEEK. These results are consistent with the study of Tian et al 58 In addition, the crystallinity of PEEK substrates decreased with increasing laser power as the higher laser energy could result in a more intense quenching process and lead to lower crystallinity. The XPS spectra of PEEK samples and the content of the elements were displayed in Fig.…”

Antibacterial nanocomposite supporting cell growth and spheroid formation by chemical surface treatment of polymer foil

“…Our results for PEEK were not so promising as for PP probably due to that pre‐activation of PEEK by Piranha solution and subsequent chemical grafting was not so successful as was for PP. Probably for PEEK is much effective to be activated by plasma or laser, as was described earlier 27–36 …”

“…Probably for PEEK is much effective to be activated by plasma or laser, as was described earlier. [27][28][29][30][31][32][33][34][35][36] The surface morphology of pristine and treated substrates was evaluated by atomic force microscopy. As it is obvious from Figure 5, surface activation of the polypropylene and subsequent grafting slightly increases the surface roughness.…”

“…Plasma 18,[27][28][29][30] or laser [31][32][33] activation has previously been tested many times on various polymer foils by many authors. Novotná et al 34 tuned PEEK by argon plasma to enhance wettability and cytocompatibility.…”