Abstract: The invention relates to a method for the producing bags (10), comprising the following steps: a tubular material (100) comprising a coating material (110) and at least one reinforcement material (120) for mechanically reinforcing the coating material (110) is provided and a base section (20) of a bag (10) is formed. The invention is characterized in that a folding section (102) of the tubular material (100) is folded about at least 180° on a connecting section (104) of the tubular material (100) for forming the base section (20), and the folded folding section (102) is connected to the connecting section (104).

Abstract: To regulate the temperature of the heated air in an apparatus for the pasting of plastic films having a rack having a table over which the workpieces are conveyed continuously by a conveyor apparatus, having a conveyor roller pair disposed in a gap of the table top and supported in the rack, consisting of a lower counter-pressure roller and an upper suction cylinder, having a conveyor cylinder acting together with the suction cylinder which successively transfers sections to the suction cylinder, and having a broad-slit nozzle directed to the roller gap which blows in a controlled manner heated air to the roller gap, the temperature directly after the pasting of the pasted region of the workpiece at which a good pasting occurs is determined as the nominal value and the temperature of the heated air is regulated to this nominal value.

Abstract: For manufacturing cross bottom valve sacks, the ends of continuously transported tubular sections are opened out with the formation of so-called "bottom squares" with triangular corner folds lying opposite each other. A valve leaf or a valve tube is tacked onto one side of an opened-out bottom square in such a way that, after the side folds of the opened-out bottom have been folded-in with a mutual overlap, the leaf forms a valve tube leading into the inside of the sack, and with its outer end freely accessible at one side of the sack bottom. For checking the correct position of the valve leaves or of the valve tube, the valve leaf or the valve tube, or the zone of the corner fold, covered thereby when the leaf is tacked in its correct position, is provided with a mark that can be registered by a photocell device fixed to the frame. The photocell device is activated by a reference pulse when, in the manufacturing installation, the sack bottom has reached its predetermined position to be checked.

Abstract: A process of manufacturing a roll of continuous synthetic thermoplastic film consisting of extruded flat film or of extruded blow-formed and flattened tubular film in which the thickness of the film is measured over the width of the film. Any striplike portion which deviates in thickness from a means thickness of the film is adjusted. The temperatures of juxtaposed temperature control sectors or the width of those portions of the slot die or of the annular die from which said striplike portions have been extruded are adjustable. When a striplike longitudinal portion having a relatively large thickness is detected in the film, the film is subsequently extruded to have a corresponding portion which has a relatively small thickness within specified thickness limits and for a length such that the two portions as superimposed in the roll have an average thickness approximately equal to the mean film thickness.