ULTRASOUND LONGITUDINAL SEALING UNIT FOR PRODUCING CONTINUOUS TUBULAR STRIPS

摘要

An ultrasound longitudinal sealing unit (5) for producing continuous tubular strips (6), wherein a continuous strip (3), as it travels along a packing path (P), is folded transversely into a U, and two longitudinal lateral portions (13) of the continuous strip are brought together and sealed to each other longitudinally to define a continuous tubular strip (6) having a longitudinal rib (17) extending along the packing path (P); the unit (5) having, to make the longitudinal seal, an ultrasound sealing device (18; 49) having a sonotrode (28) and an anvil (37; 52) on opposite sides of the packing path (P), and wherein the anvil (37; 52) is mounted to oscillate to and from the sonotrode (28) about an axis (40) crosswise to the packing path (P), and in opposition to and by virtue of elastic means (44) respectively.