An assembly for producing sealed packaging units (14) from a sheet packaging material, comprises: an advancement device (21) for advancing the sheet packaging material along an advancement direction (F), a longitudinal sealing device for sealing opposite borders of the sheet packaging material along a longitudinal sealing band arranged parallelly to the advancement direction (F), thereby forming a continuous tube (15), a transverse sealing device (29) for sealing the continuous tube (15) transversely to the advancement direction (F), so as to define a sealed packaging unit (14). The transverse sealing device (29) comprises a sealing element (30) and an abutment element (31) that are intended to mutually cooperate during sealing while being located on opposite sides of the continuous tube (15). The sealing element (30) is so configured as to act on a side (27) of the continuous tube (15) on which the longitudinal sealing band is provided.

A device for processing, in particular for ultrasound welding, of packaging sleeves and/or packagings includes at least two tools for processing, in particular for ultrasound welding, of packaging sleeves. Each tool has an operating region. The tools are supported in such a manner that there is produced between the operating regions a gap whose longitudinal direction corresponds to the transport direction of the packaging sleeves, and the tools are supported in such a manner that the size of the gap can be changed. In order also to enable continuous welding of the packaging sleeves in a reliable manner with changing material thicknesses, there is provided at least one parallel spring on which at least one of the tools is movably supported transversely relative to the transport direction of the packaging sleeves.

An apparatus successively makes plastic bags each of which includes an end surface provided with a protrusion, without specially supplying a web of bottom gusset material. A first web of panel material is folded along a first folded line at a position adjacent to a side edge of the first web, while a second web of panel material is folded along a second folded line at a position adjacent to a corresponding side edge of the second web. A first folded portion is formed in the first web. There exists a distance between the side edge and the first folded line, which is larger than twice a distance between the corresponding side edge and the second folded line by a predetermined distance, after being folded. The end surface is formed by the first folded portion, the protrusion being formed by the predetermined distance.

A counter-pressure roller for applying pressure on a longitudinal sealing of a packaging material web comprises, a first back-panel support section having a first radius and a second back-panel support section having a second radius, for supporting first and second back-panels of the web, respectively. The first radius is greater than the second radius, and a groove is between the first and second back-panel support sections, for holding a longitudinal overlap section formed by first and second edge sections of the first and second back-panels, respectively. The first edge section is positionable outside the second edge section, with the first edge section facing a bottom of the groove. The bottom has a third radius less than or equal to the second radius. The groove has a first groove edge section having a first inclination, and a second groove edge section having a second inclination.