A smooth visual appearance and minimum noise emission need to be provided from modern roof structures. They consist of all kinds of materials like aluminum, steel, plastics or carbon fiber, which require special consideration. Atlas Copco can support with advanced joining process knowledge.
Roof panels are so large, so they need to be supported and dampened to reduce noise during car operations. Hot butyl or rubber-based adhesives between the inner skin and outer panel is a common solution.
Traditionally most car manufacturers use standard bead applications not only for hybrid joining but also for the anti flutter applications. By connecting the inner and outer parts with elastic material, vulnerability to vibrations is successfully reduced.
Hemmed seams are also important when having sunroofs. When doining hem flange bonding, the parts have to be precisely filled with adhesive to avoid corrosions and to achieve a perfect hem flange.
Applying a continous bead is the favoured way for many manufacturers today. A method to improve production quality in hem flange bonding is the Swirl technology.