Method and device for forming open bottoms on end regions of tubular bag bodies

Abstract

In a device (1) for forming an open bottom in an end region (10e) of a tubular bag body (10), the bag bodies (10) are transported in a flat manner in a transporting direction (T) transverse to the bag body longitudinal extension (L) at a transporting speed (V), and the end regions are opened with an opening device (20). A widening tool is introduced into the opened end regions (10e) of the bag bodies during their transportation on the transporting device and moved in the transporting direction (T) at a speed (V1R) that is increased relative to the transporting speed (V) until front contour points (23p, 24p; 33p, 34p) of said tool run against the inner face of the bag body on the front part (10v) of the opened end region. Said tool widens the front part (10v) into a front corner flap (10j) in the form of an isosceles triangle. The widening tool (21, 30, 32) is moved out of the front corner flap (10j) by slowing of the movement of said tool with respect to the transporting speed (V) after formation of the corner flap (10j). The corner flap is pressed with a pressing device (28, 35, 36).

Description

technical field The invention relates to a method and a device for forming an open bottom at the end region of a tubular bag body, which is preferably produced from a fabric made of stretched plastic tape, wherein the bag The body is transported lying flat at a transport speed in a transport direction transverse to its longitudinal extent, and the end region of the tubular bag body to be folded is opened during transport. Background technique Box bags (Kastensack), also known as cross-bottom bags (Kreuzbodensack) are bags of square configuration, which are manufactured in bag-forming equipment (by providing a tubular bag body whose open end regions are folded into a cross-bottom panel) . The bag is guided through the forming device lying on its back, so that the two layers of the tubular bag rest against each other. For the bottom formation, the two layers are separated from each other at the end region of the tubular bag body and one of the two layers is folded in half by...

AI Technical Summary

Problems solved by technology

In this known device, the corner flanges are formed together by turning over a bottom side cover, but due to geometrically uncertain initial conditions, do not always have the desired precise shape, so that by positioning the valve plate The inclusion of the bottom side flaps and the connection to the bottom flap also make reprocessing of the bottom of the bag difficult

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