Device and method for producing and sealing packagings produced from at least one heat sealable packaging material strip

Abstract

A tubular bag-making machine for forming a flexible tube from a hot-sealable web of packaging material sealed longitudinally by means of a longitudinal seam sealing device and transversely by means of a transverse seam sealing device to produce individual tubular bag packages. To improve the transverse sealing seams, bores which can be made to communicate in alternation with a negative-pressure source or an overpressure source are embodied in the sealing jaws of the transverse seam sealing device in regions having a reduced number of layers of packaging material to enable a good heat transfer and a higher sealing pressure in the region of changes in the number of layers of packaging material of the transverse sealing seams.

Description

PRIOR ART[0001] The invention relates to an apparatus and a method for producing and closing packages, made from at least one hot-sealable web of packaging material, as generically defined by the preambles to the independent claims.[0002] One apparatus having the characteristics of the preamble to claim 1 is already known from German Patent Disclosure DE 43 35 577 A1. In producing packages with the known kinds of apparatus, the problem arises that over the cross section of the flexible tube formed, there are regions with varying numbers of layers of packaging material. This can for instance be due to the fact that a previously formed longitudinal seam is wrapped around a wall of the bag, so that in the region of the longitudinal seam there are four layers of packaging material, while in the region immediately next to it there are only two layers of packaging material. It is also usual to fold the web of packaging materials inward in a V in the bottom and top regions, so that in thes...

AI Technical Summary

Benefits of technology

[0005] The apparatus according to the invention for producing and closing packages made from at least one hot-sealable web of packaging material and having the definitive characteristics of claim 1 has the advantage that with a relatively simple structural embodiment, it makes tight transverse seams and at the same time a high output of the apparatus possible.[0006] The invention makes use of the thought that for producing tight sealing seams, adequate warming of the packaging material must be assured, particularly in the regions of the transverse seam to be formed that have a reduced number of layers of packaging material. While when the two sealing jaws are pressed together, good heat transfer from the sealing jaws into the packaging material is assured in those regions with an increased number of layers of packaging material solely by the pressure of the sealing jaws, in the regions with a reduced number of layers of packaging material, the heat transfer is reduced in those regions with a reduced number of layers of packaging material, because of the reduced initial pressure of the sealing jaws against the packaging material. It is therefore proposed according to the invention that suction openings be provided in these latter regions, which openings pull the packaging material against the heated sealing jaw and thereby assure a high heat transfer.[0007] Another preferred embodiment of the invention provides that the suction openings be made to communicate with a negative-pressure source. This makes it possible to press the layers of packaging material, after they warm up, against one another by means of the overpressure, so that a more-intimate contact between the warmed layers of packaging material and thus a tighter transverse seam can be formed.

Problems solved by technology

In producing packages with the known kinds of apparatus, the problem arises that over the cross section of the flexible tube formed, there are regions with varying numbers of layers of packaging material.

The presence of different numbers of layers of packaging material over the cross section of the packages is problematic because in forming the transverse seams, it must be assured that the packages later cut apart from the flexible tube of packaging material have adequate tightness.

There are limits, however, to both transferring suitable quantities of heat and applying suitable sealing pressures, especially when critical packaging materials are used or for the sake of output.

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