New joining technique

The highest priority when developing the innovative joining process was process-safe curing within ideal cycle times and geometric design. A threaded bush is used which is provided with sufficient adherend due to an enlargement in diameter in the lower area. The resulting cavity provides reproducable layer thicknesses and ensures that the adhesive suffuses the complete joining part surfaces. The benefit: Spare adhesive and particularly enclosed air leak out through a drilling hole into the interior of the threaded bush. The adhesion process is carried out in three easy steps: Application of adhesive, setting of the thread element and curing.

Highly flexible dual-curing acrylates are used. That way, the components easily survived the so-called "Random Free Fall Test" (ten falls from a height of 1.5 meters onto a stone floor). Another benefit is that the adhesive cures within seconds.

Böllhoff Verbindungstechnik GmbH based in Bielefeld and DELO Industrie Klebstoffe have developed a new adhesion system to process-safely attach thread elements to wafer-thin metal housings of mobile phones or handheld devices.