Automated application technology for adhesives and sealants

Individual solutions for automated adhesive bonding and sealing processes

The Fraunhofer IFAM in Stade develops automated, forward-looking joining and sealing processes for numerous branches, including aviation and space, automotive engineering, rail vehicle construction, shipbuilding and the energy sector, up to full-scale. The individual solutions are based on the application-specific requirements for joining or sealing of structures.

The range of services includes consulting as well as the characterization of application-relevant parameters and process-specific requirements for the use of suitable adhesives and sealants as part of research and development work (R&D work). On this basis, a compatible robotic end effector system can be selected or developed. The mixing of the two-component material and the application technology are also taken into account. Based on customer-specific requirements, this allows complete joining and sealing processes to be designed for production.
 

Increased efficiency through automated adhesive bonding and sealing processes

Adhesives and sealants are used not only for joining components but also for sealing edges and open structures as well as for compensating of tolerances in the gap between components (“shimming”). While an individual, manually executed joining process may often appear comparatively straightforward, the complexity in adhesive bonding technology increases significantly as precision requirements rise. In particular, the human factor and the need for a high level of personnel qualification make manual processes prone to errors. For this reason, automation plays a considerable role in enhancing process reliability, especially in precision-critical adhesive bonding processes and can therefore reduce effort as well as costs in the long term.

The Fraunhofer IFAM in Stade has a wide range of robotic systems at its disposal, including both large industrial robots and small lightweight robots. This equipment enables the development and implementation of customized solutions for adhesive bonding and sealing processes, ranging from laboratory scale up to full-scale demonstrator.
 

Challenges with dosing systems

When dosing two-component materials, different mixing ratios and the respective density of the individual components result in various requirements for automated and complete mixing of the two components. This means that different conveying principles must be taken into consideration when dosing.

For this reason, Fraunhofer IFAM offers a variety of end effectors with different material delivery methods, including piston pumps, gear pumps and progressive cavity pumps. This allows a wide range of application scenarios to be realized with different adhesives and sealants.

The optimum selection for a specific customer application depends on the quantities to be processed, the resulting volume flow and also on the composition of the adhesives and sealants.

The properties of adhesive systems can vary considerably depending on the application, meaning that the mixing must be evaluated and adapted individually. Various mixing systems are available in Stade for this purpose, including static mixing tubes, dynamic-static mixers and dynamic mixers.

Quality-assured complete solutions for high-precision automated adhesive bonding and sealing processes

The development of automated joining and sealing processes is a central core competence of the Fraunhofer IFAM in Stade in the field of Joining and Assembly. The scientists carry out systematic and application-oriented research into the automated use of adhesives and sealants for various branches of industry. The team has comprehensive specialist knowledge, state-of-the-art technologies and extensive experience. Based on a holistic process approach, the researchers develop customized solutions – from cleaning and activation to the precise application of materials up to comprehensive quality control. Specific application nozzles can also be developed for the respective process in order to apply the desired adhesive seam with high precision and reduce the amount of masking required for the components to be bonded.

Automated surface pre-treatment prior to adhesive bonding and sealing is a central area of R&D activities. Cleaning and activation processes such as vacuum suction blasting are designed, tested in terms of process technology and metrologically validated in Stade, thus covering an end-to-end process chain.