ROTARY ULTRASONIC SEALING

摘要

The invention is an apparatus for forming an ultrasonic weld that includes a sonotrode having an ultrasonic actuator coupled to an elongate sealing end face for delivering ultrasonic energy to the webs in the sealing gap and a rotating cylindrical anvil having at least one raised portion extending longitudinally along an outer surface thereof. The raised portion has a radially outer surface, whereby the sealing gap is defined intermittently between the end face of the sonotrode and the radially outer surface of the raised portion of the anvil as the raised portion rotates past the end face of the sonotrode. The elongate sealing end face of the sonotrode has a substantially helical surface, whereby the sealing gap travels helically along the surface as the raised portion of the anvil cylinder rotates past the end face of the sonotrode.