Sealer apparatus for plastic film processing including an adjustably mounted seal bar, particularly for bag making machines

摘要

A cross sealer for a plastic bag making machine includes a frame with an upper moveable seal bar unit and an opposed lower stationary seal bar unit. The movable unit is a lightweight construction seal beam. A rotating shaft spans the cross sealer and is connected by a plurality of eccentric linkages to the seal beam. The linkages moves a seal bar into sealing engagement across the width of the web to the seal bar unit constructed with a support beam and a seal bar connected to the beam. The seal bar unit is mounted as a substantially stationary unit during sealing and is supported by a plurality of air cylinder units for positioning from standby to an operating position. Each air cylinder unit includes an adjustable stop unit secured to the back of the cylinder unit and connected to the cylinder piston for adjusting the movement of the piston and thereby the operative sealing position of the stationary seal bar unit. Some air cylinder units are connected to the seal bar unit for positively moving the same and others additionally includes pad abutting the seal bar units for supporting the same between the two positions.