The BHS HOT STAMP® process is a so-called hot stamp riveting process. The rivet head is equipped with a stamp that can be changed quickly. The stamp can be individually selected for each rivet geometry and easily exchanged. Precise and fast temperature control, based on continuous temperature measurement directly at the contact point between the stamp and the rivet pin, also known as the plastic dome, allows the rivet pin to be brought to the optimum melting temperature and formed quickly and stably. In this way, even highly filled, high-temperature-resistant semi-crystalline thermoplastics, so-called high-performance polymers or engineering plastics, can be processed reliably.
The forming movement is performed by an infeed integrated in the rivet head, the caulking pressure of which is variably adjustable. A displacement measuring system monitors the position of the rivet head and thus the presence of a rivet pin and the end position. Safe and thread-free removal without pre-weakening of the riveted joint is ensured by an integrated air cooling system. The process control is variable and is carried out individually, product- and requirement-specific.
Process sequence
First, the stamp is heated up. As soon as it has reached the process temperature, it is moved onto the rivet pin with preset pressure and melts the material until it has reached the end position and formed a rivet. Finally, it is actively cooled, the stamp is detached and moved back to the home position. With one riveting head, all process steps of heating, melting, forming, cooling and detaching are carried out, so that this process is also referred to as the "single-cycle process".
