Low-emission laser material processing of plastics and composite materials

During manufacturing processes, the material interaction with high power laser sources and the achievable high peak densities gain more and more importance for industrial applications. Besides the many advantages of laser material processing, most applications are based on thermal processes, which cause significant emissions and pollution. In the last 5 years, the developments in the field of fiber-reinforced composites led to a growing interest and demand of engineers for lightweight designs. The trend of new lightweight materials and, especially, the supplement of carbon nanotubes and graphene, requires a substantiated scientific approach for handling emissions. This includes a rethinking of manufacturing processes to ensure a safe interaction between operator and machinery in the industrial environment. This work provides fluidic and design simulations to characterize the emerging process emission, which includes solid particles and gases near the point of origin. In a first step, the air circulation during the production process is simulated applying computational fluid dynamics in Ansys. Here, the selected constraints of the numerical model and the spatial rough discretization in the region of the high current gradient are important to ensure accurate results. Next, the generated numerical models are transferred into experimental investigations. The measurement of particles is discussed for six different plastic substrates (PC, PMMA, SAN, PE, TPE, PP). The approaches of the design concept are tested with the help of experimental visualization methods for the airflow. Selected results for a low-emission laser material process are introduced and evaluated for different machine concepts, such as laser scanner units. Due to the volume flow rate and the power level of the extraction system, the results can be evaluated.