Numerical and experimental studies on the influence of gas pressure on particle size during gas-assisted extrusion of tubes with embedded antibacterial particles

During the gas-assisted extrusion process of plastic tubes embedded with antibacterial particles, the particles tend to agglomerate. The dispersion effect of these agglomerates using the nozzle-pressure-difference method is significantly influenced by the gas flow state. Therefore, this study establishes the nozzle dispersion model. The gas flow state near the nozzle is simulated and analyzed by using Ansys Fluent software. Gas-assisted extrusion experiments are conducted with different nozzle inlet pressures, and the size distribution of antibacterial particles is observed by using electron microscopy. The simulation results indicate that increasing the nozzle inlet pressure enhances the dispersion effect and expands the effective dispersion area. The experimental results demonstrate that using the nozzle disperses the agglomerates into particles with a diameter of approximately 100 nm. Furthermore, the nanoparticles diameter size decreases with the increase of the inlet pressure, validating the accuracy of the numerical analysis results.