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Efficient air flow control plays a crucial role for the reliability of remote laser beam welding applications.Local air flows are helpful to suppress unfavorable interactions between laser radiation and welding fumes as a result of absorption and/or scattering effects. On the other hand, local and additional global flows have to be applied for emission control to protect optical components and workpieces from contamination and to avoid harmful air pollution of the atmosphere. However, the appropriate design of complex air flow systems under the additional condition of preferably low overall gas consumption is still a challenging task because a high number of decisive factors and a multitude of possible interactions complicate the pure empirical selection and positioning of suitable flow components and the adjustment of the numerous control parameters. This paper presents the results of a combined and complementary approach of experimental and theoretical investigations to meet these challenges. The experimental work was focused on the aspects of interaction mechanisms between the laser beam and the welding fume. Besides the characterization of process emissions some of the requirements of stable remote processing with maximum penetration depth are revealed. In contrast, the theoretical work describes a general methodology on how to support the optimization of the cabin air flow by means of Computational Fluid Dynamics (CFD) models in combination with Design-of-Experiments (DoE) approaches.

“Passive” and “active” laser-protective clothing and curtains are hardly available on the market today for the use with hand-held laser processing devices (HLD) and automated laser machines. However, the fact that serious laser injuries of the skin happen shows that skin protection against laser radiation is necessary. Thus, key developments described in this paper are on the one hand highly innovative functional multi-layer technical textiles, providing a high level of passive laser resistance. On the other hand, active systems, containing functional multi-layer smart fabrics which detect laser exposure and, by means of a safety control, deactivate the laser beam automatically, are depicted. Furthermore, test methods and testing set-ups to qualify such passive and active functional technical textiles and tailored personal protective equipment (PPE) are developed. The passive laser-protective textile system will be realized using the best combination of materials, providing, at the same time, laser, fire, and heat protection together with other properties. Designing active system means the realization of functionalized fabrics and to exploit their physical properties. The electronics which interface the active system, providing signal conditioning, acquisition, on-body pre-processing, local data storage and wireless communication, is a major part of the active approach. The electronics will provide alarms and ultimately enforce laser shutdown upon defined conditions.

In the case of serious accidents, severely injured persons may be trapped inside damaged vehicles and thus must be rescued quickly. Typically, structural parts containing high-strength steels or fiber-reinforced plastics must be cut to generate rescue openings. Hence, mechanical rescue systems like hydraulic shears may reach their performance limits. Therefore, a mobile laser cutting device for rescuers has been developed, being suitable for harsh outdoor conditions and providing optimized robustness, handleability, and weight. A crucial aspect is the requirement of laser safety for all persons involved. Here, the description of the first version of a demonstration system consisting of a mobile laser cutting device for complex rescue operations is presented.