Apparatus for producing and filling tubular bags

摘要

A heat-sealable foil is shaped around a shaping pipe to form a tube and during removal from the shaping pipe is provided with transverse seams by means of transverse heating jaws. The resulting bags are filled by means of a fill pipe and a dosaging worm or auger. A conduit leads from the lower end of the shaping pipe to a bellows and to a bottle of protective gas. The bellows forms a closed chamber whose volume is periodically increased and reduced in the operating rhythm of the bag forming apparatus by means of drive members. Thus the pressure conditions at the end of the shaping pipe can be influenced periodically, so as to avoid that the filled or sealed bags contain undesirable air inclusions or, when filling under protective gas, so as to avoid greater losses of protective gas from leaking into the open air.