Process emissions during laser processing of CFRP: measurement of hazardous substances and recommendation of protective measures
Proc. Lasers in Manufacturing (LiM)
Type: Zeitschriftenaufsatz (non-reviewed)
Regarding resource-efficient lightweight structures, carbon fiber reinforced plastics (CFRP) have a high usage potential due to their outstanding mechanical properties, especially their high specific strength parallel to the carbon fibers. Adequate processing methods are required to enable high-quality mass production of CFRP parts e.g. in the automotive industry. So far, mechanical methods associated with notable tool wear are used in most applications. Laser technology used for CFRP processing may provide diverse advantageous features such as contact-free processing without any tool wear, high contour accuracy and reproducibility, and high flexibility concerning workpiece design. In a particular funding line, the German Federal Ministry of Education and Research (BMBF) supports several cooperative research projects, dealing with the development of processes for innovative lightweight structures, using CFRP materials amongst others. If specific laser processing strategies are used for CFRP materials, high quality results can be achieved. However, CFRP laser processing as a thermal method always produces organic particulate and gaseous process emissions. The substances released into the air at the workplace are connected with the risk of adverse health effects for the employees, and the potentially hazardous compounds in the exhaust air, removed from the processing cabin, may be harmful for the environment. With respect to the risk assessment, measurements have been performed in the course of the BMBF-funded projects dealing with CFRP laser processing, yielding emission rates and workplace concentrations which have been related to the respective limit values (emission limit values for the exhaust air and occupational exposure limits for the workplace). The results are used to develop recommendations for adequate measures to protect the employees as well as to handle the process emissions in terms of filtering for environmental protection.