Upon cutting a corner of a plastic bag, the cut-out portion is prevented from attaching to the plastic bag. A plastic film (1) is trimmed by a trimming cutter (7) to form a selvage (8). Every time that the plastic film (1) is intermittently fed, the trimming cutter (7) is moved by a trimming cutter moving mechanism, so that a corner of the plastic bag is cut by the trimming cutter (7) and the cut-out portion (11) is continued from the selvage (8).

A method, a cutting device and an apparatus wherein, at cusp-shaped recesses obtained by die cutting on a ribbon in order to obtain pouches with rounded corners, the ribbon is cut transversely by means of at least two strokes of a blade. A relative translation is performed, between the first stroke and the second stroke, between the cutting plane and the ribbon substantially along a feeding direction of the ribbon, so as to level with the second stroke any cutting defects of the first stroke in the region of the recess.

The provided are a four side seal packaging bag and a preparation device and method thereof. The preparation device includes at least: a film material conveying mechanism, configured to continuously convey a film material of a packaging bag along a length direction of the film material; a folding mechanism, configured to fold the film material conveyed by the film material conveying mechanism; a cutting mechanism, configured to cut the upper film material; punch-and-cut mechanisms, configured to form square punch-and-cut regions and separate the square punch-and-cut regions from the side accordion film materials; a side accordion forming mechanism, configured to perform a forming operation on the side accordion film materials; and a hot-sealing mechanism, configured to hot-seal the upper film material, the formed side accordion film materials, and the lower film material.

The present disclosure includes paper bags and methods for forming paper bags. Some of the bags may include a body, a first attachment portion configured to engage an arm of a bag holder, and a second attachment portion configured to engage another arm of the bag holder. In some aspects, the body defines an opening and includes opposing first and second sides, a first section disposed between the first side and the second side, and a second section disposed between the first and second sides, the second section moveable relative to the first section to define a cavity that is in communication with the opening. The first attachment portion may be closer to the first side of the body than the second side and the second attachment portion may be closer to the second side of the body than the first side.