Anvil-Free Ultrasonic Welding for Welding Situations With Accessibility From One Side Only

Because of the good automation capacity and the simple process management, ultrasonic welding is being utilised in series production to an increasing extent. Conventionally, the procedure is carried out in a standardised form using an anvil and the joining region must thus be accessible from both sides. This requirement constitutes one of the essential restrictions of the procedure. Until now, the current state of the art has not permitted any efficient use of ultrasonic welding in conditions with accessibility from one side. The objective of these investigations was therefore to determine a minimum stiffness of the bottom joining member which makes it possible to use this as a functional anvil and to attain constant weld qualities in this way. Therefore, it is not necessary to have accessibility from both sides, as in the case of conventional ultrasonic welding. Before any welding investigations have been conducted, the identification of this stiffness limit already permits assessments of whether an additional anvil is required or can be dispensed with. This potentially contributes to the extended applicability of ultrasonic welding.