Heat seal apparatus, bag machine, and bag edge forming apparatus with resilient tubular anvil

摘要

An apparatus is provided for forming bag edges in a layered plastic film. The apparatus includes a heated seal bar and a seal bar anvil. The seal bar anvil has a resilient tube configured to deform as the seal bar is driven into the tube to seal and sever a bag edge therebetween. According to one construction, the resilient tube is pressurized pneumatically from the inside so as to impart a specific, desired resilience to the tube as the tube and seal bar co-act on either side of the layered plastic film.