Continuous ultrasonic welding of e.g. plastics by cyclic weld pressure - with thick webs or delicate surface, giving seam of overlapping welds with min deformation and without tearing of pinholes

摘要

Continuous ultrasonic welding of materials, esp. in the form of webs, in which the welding pressure is applied cyclically esp. during the stationary period in an intermittent material motion, which may be synchronised with the application of weld pressure, resulting in a seam of overlapping weld sections. The intermittent material motion may be by an anvil in the form of a wheel which is rotated intermittently. Alternatively, the material may be hauled by intermittent drives, synchronised with the movement of the anvil to apply weld pressure. The anvil may be the core of an electromagnet or a rocker arm rotated electromagnetically. ADVANTAGE - Permits satisfactory continous welds in thicker materials and/or with delicate surfaces, without tearing at entrance to horn/anvil gap, holes in the material or poor quality seams, compared with continuous weld pressure, e.g. by a spring. Material deformation at entrance to horn/anvil gap is reduce