NL6905187A - Block-shaped plastic bags prodn. - Google Patents

Abstract

Plastic bags, optionally provided with a filling valve, are produced by (a) forming at least one lengthwise incision in a tubular film from end and of the film to form a first corner flap between the lengthwise incision and the adjoining lengthwise edge of the film, (b) outwardly folding the bottom flap parts lying next to the lengthwise incision on the other side, around the fold line in the tubular film part from the incision point, (c) inwardly folding the bottom flaps around a transverse fold line situated between the fold line (b) and the line passing perpendicular to the tubular film lengthwise edges through the lengthwise incision and point, and (d) welding together the bottom flap parts. The tubular film has bottom flap parts placed next to the incision with end edges sloping relative to the lengthwise edges of the tubular film, and the bottom flap parts are folded inwardly around a transverse fold line situated between the fold line of (b) and the line moving perpendicular to the lengthwise edges of the tubular film through the lengthwise incision end point, while the triangular parts of the second corner flap situated next to the transverse fold line are folded back under the remaining part of the corner flap.