FORFARANDE OCH ANORDNING FOR FORMANDET AV EN HALLBAR, HERMETISK SVETSSOM MELLAN PLASTSKIKTEN I EN LAMINERAD PLAST-METALLKROPP

摘要

A sealing apparatus for joining container parts of a plastic-lightweight metal foil laminate by heat and pressure applied to the laminates when the respective plastic layers are pressed into contact uses a toggle linkage and a yieldable buffer, with a hydraulic actuator to drive the toggle linkage to close a pair of sealing heads together. The toggle linkage permits build-up of pressure to a value predetermined by the construction of the buffer, after which the buffer yields to hold the sealing pressure. The duration of the build-up to sealing pressure comprises no more than 20% of the time interval between initiation of pressure build-up and the start of pressure drop-off at the end of the sealing process.