Process and Mechanism of Cutting Polyamide Films with an Ultraviolet Picosecond Laser

Polyamide (PA) films have been widely utilized in high-precision medical devices and aerospace components, while laser precision cutting technology has significantly broadened their application scope. Although ultraviolet (UV) picosecond lasers are effective for high-precision cutting of PA films, their cutting mechanism and the optimization method for the process remain to be elucidated. First, the mechanism of UV picosecond laser cutting of PA films was investigated through a simulation of the thermal degradation process and analysis of the solid/gas byproduct composition. The results indicate that the photochemical reaction primarily dominates the process, with the photothermal effect contributing synergistically. Second, a cutting quality evaluation framework was established, with the kerf width and heat-affected zone (HAZ) width as its primary metrics, followed by an orthogonal experiment. The experimental results revealed the influence of process parameters on the cutting quality, and it was determined that an optimal process parameter combination exists, identified as 80 mm/s, 1.67 W, and three times (cutting speed, laser power, repetition number of cutting). Under this optimal configuration, narrow kerf (23.6 ± 2.7 μm) and HAZ (28.4 ± 3.3 μm) were achieved.