Abstract: A paper bag is formed from a single sheet of paper by folding the same to produce a final generally rectangular bag or receptacle with an open end. The upper edge portion around the bag opening is folded in and glued to provide greater strength thereat. During the folding and glueing of this opening strength turned-in collar, two carrying handles are also glued in, one on each of the bag's largest sides. According to this invention, a corner portion at one end of the turned-in collar portion is cut out and enables glueing thereat to an inner surface rather than the typically smoother outer surface of the paper, thereby providing improved strength to the reinforced opening of the bag.

Abstract: A lapel provided at the one end of a paper sheet to forming a paper bag is introduced into the interior of an opening on the rotary cylinder by means. The folding blade has a rotational axis located outside the rotary cylinder parallel to an axis of rotation of the rotary cylinder. The thus bent lapel is brought in pressure contact with the edge face of the opening by means of a holding pawl which turns in operative association with the rotary cylinder. Thereafter, the lapel is covered and depressed by means of a depressing pawl which turns in operative association with the rotary cylinder whereby the lapel and a part of the paper sheet are adhesively secured to one another to build a double-walled structure around the opening of the paper bag.