Picosecond Laser Processing – Material Removal Rates of Plastics

A picosecond UV laser has been used to establish the material removal rate of plastics. Varied processing parameters include laser power, pulse frequency and scanning velocity. The wave length of the laser used was 355 nm. Scanning velocity varied between 100 to 800 mm/s and repetition frequency between 10 to 500 kHz. Materials for the experiments were generally used plastics, which were available as a plate. Results reveal that an optimal fluence can be established for all of the examined polymers. For each material an optimal pulse energy range can be found in which the material removal rate reaches it’s maximum at a given laser power. The ablation threshold, required power and optimal pulse energies are generally lower for plastics than for metals. The processing of PE and POM needed higher laser powers and pulse energies than other tested plastics. In the case of plastics, parameter combinations which lead to poor processing result can be easily found. These parameter combinations can produce color change and unwanted reaction products to the surface of the material.