Laser radiation as a robust tool for the surface pre-treatment of FRP prior to adhesive bonding

Abstract

Within the research project “ProPhoMuLA“, funded by the Federal Ministry of Education and Research (BMBF), fundamentals for innovative laser pre-treatment processes for fiber reinforced plastics (FRP) are elaborated in order to improve the adhesive joining properties of multi-material joints, e.g. FRP-FRP or FRP-metal-joints.The increasing application of material mixture results in a growing importance of the adhesive bonding technology as the most promising joining technique for multi-material joints. Until now, the use of adhesive bonding for multi-material joints is, however, connected with high process-technical expenditure. In addition, despite the successful implementation in individual applications, the methods have not yet been sufficiently developed for automotive large-scale manufacturing. One of the most important challenges is the provision of robust surface pre-treatment methods in order to ensure efficient and durable adhesively bonded joints. The possibility of in-line application is an advantage of the laser pre-treatment compared to other surface pre-treatment technologies such as sand blasting or grinding. Therefore, the application of laser pre-treatment technologies based on photonic production methods is predestined for this task.Numerical simulations are performed to analyze the influence of the laser surface pre-treatment on automotive product developments. Suitable simulation methods are identified and validated regarding the functionality of the considered approach.The results of empirical investigations show that the laser pre-treatment is suitable, especially for the pre-treatment of thermoplastic FRP, where an increase of peel resistance to the factor of four in comparison to conventional pre-treatment techniques can be achieved.Within the research project “ProPhoMuLA“, funded by the Federal Ministry of Education and Research (BMBF), fundamentals for innovative laser pre-treatment processes for fiber reinforced plastics (FRP) are elaborated in order to improve the adhesive joining properties of multi-material joints, e.g. FRP-FRP or FRP-metal-joints.The increasing application of material mixture results in a growing importance of the adhesive bonding technology as the most promising joining technique for multi-material joints. Until now, the use of adhesive bonding for multi-material joints is, however, connected with high process-technical expenditure. In addition, despite the successful implementation in individual applications, the methods have not yet been sufficiently developed for automotive large-scale manufacturing. One of the most important challenges is the provision of robust surface pre-treatment methods in order to ensure efficient and durable adhesively bonded joints. The possibility of in-line application is an adv...