NL8601274A - PLASTIC BAG WITH A SIDE FOLD ON BOTH SIDES INCLUDING ADDITIONAL WELDING PROVEN ON THE FOLDING EDGES IN THE MAIN CASE, AND APPARATUS FOR MANUFACTURING SUCH PLASTIC BAG. - Google Patents

Abstract

The plastic foil bag (27) has concertina-folded longitudinal sides each with a central inner fold (4;4a) and two outer folds (2,3; 2a,3a) either side. A transverse bottom weld (12) extends across outwardly upwardly diverging weld lines (8,9; 10,11) which each connect an outer foil layer (1a,1b) with the respective facing inward concertina fold portion (5,6; 5a,6a). Similar inclined weld lines (13,14; 15,16) arranged at the upper end converge to the open end (28) of the bag. Additional weld lines (30) are arranged on either side at top and bottom of the bag and extend parallel to and between the respective longitudinal inner and outer side folds. At the top of the bag, these weld lines (30) are connected with the weld lines (13,14; 15,16) and extend therefrom to the open end.

Description

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855162 / vdV / kd

Short indication: Plastic bag with a side fold on both sides provided with additional welds which run substantially parallel to the folding edges, as well as a device for manufacturing such a plastic bag.

The invention relates to a plastic bag with a side fold on both sides, each side fold comprising a middle and two outer accordion folding longitudinal edges, which define a first and a second accordion folding part, the bag comprising the following parts: a) a bottom transverse weld b) two first accordion folding sub-welds on both sides of the bag, the first accordion folding sub-welds always joining an outer foil sheet to the opposite accordion folding part and the first accordion folding sub-welds extend between the middle and the outer accordion longitudinal edges in the region of the bottom transverse seal and from the bottom transverse edge to the outer fold edge diverge; c) two second accordion folding sub-welds on both sides of the bag, the second accordion folding sub-welds always joining an outer foil layer with an opposite accordion folding part and the second accordion folding sub-welds between the middle and the outer accordion longitudinal edges, at the end of the bag and at a distance from the bottom transverse weld 20 The two accordion folding sub-welds converge from the outer longitudinal fold edges to the open mouth of a bag.

Such a plastic bag is known. One of the drawbacks of this bag is that in the filled bag, the forces acting in the area where the center accordion fold longitudinal edge and the bottom transverse seal meet are rather poorly distributed and, moreover, fill material which in the side fold parts during filling of the bag , may cause difficulties in sealing the bag after filling the heat seal 30.

The object of the invention is now to provide a plastic bag of the type mentioned at the outset which does not have these disadvantages.

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This object is achieved according to the invention in that additional welds extend substantially parallel to the folding edges and in the region between the inner and outer harmonica folding longitudinal edges on both sides of a bag, the additional welding having the second folding part welds. are connected and extend from the second accordion folding part seals toward the open end of a bag.

The additional welds used in accordance with the invention can be easily applied, facilitate sealing of a filled bag, while the forces acting in the region where the center accordion fold longitudinal edges and the bottom transverse seal meet are much better distributed.

Preferably, the additional welds extend near the inner folding edges, that is, the distance between the additional welds, the nearest center accordion folding longitudinal edge is no more than 20% of the distance between these middle and the nearest second second accordion folding longitudinal edges.

Advantageously, the additional welds extend to a filling opening of the bag, and the first accordion folding welds are also connected to additional welds that extend to at least the bottom cross weld.

According to a preferred embodiment, the additional welds run on both sides of a bottom cross weld.

In this way a particularly suitable plastic bag is obtained which can be easily closed and, moreover, takes on the desired shape after filling and sealing.

Advantageously, a plurality of bags are combined into a web provided with wall attenuations to separate an open-ended bag from the web.

Finally, the invention relates to a device for manufacturing a plastic bag according to the invention, comprising at least transport devices for the step-by-step transport of a plastic film, first welding members for forming first accordion folding part welds, 8601274

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Second spindles for forming second accordion fold sub-splices and transverse splicers for forming a bottom transverse splicer, characterized in that the apparatus comprises fourth splices for forming additional splices.

The invention will now be elucidated on the basis of an exemplary embodiment with the aid of the drawing, in which:

Fig. 1 - shows a plastic bag according to the invention;

Fig. 2 - a web of several interconnected plastic bags according to the invention;

Fig. 3 - a tubular film with first and second folding part welds and additional welds;

Fig. 4 - the manner in which bottom transverse welds are formed with the device according to the invention; FIG. - the means for forming first and second folding part welds as well as additional welds; and FIG. 6 - the film forming after first bottom transverse welding.

Fig. 1 shows a plastic bag according to the invention 20 with accordion folds along the longitudinal sides, each bag 27 comprising two outer accordion folding longitudinal edges 2, 3 and 2a, 3a, respectively, as well as a accordion folding longitudinal edge 4 and 4a, respectively.

The bag is provided at one end with a first bottom transverse seal 12 through which the superimposed foil layers 1a, 1b are joined together at least in the region between the center accordion fold longitudinal edges 4, 4a.

As can be seen, the first bottom transverse seal 12 also extends to the outer accordion folding longitudinal edges 2, 30, 3, 2a, 3a with the superimposed foil layers 1a and 1b interconnected and in the edge regions the foil layers 1a and 1b and first accordion folding part 5 and second accordion folding part 6 are all connected to each other.

In order to obtain a block bottom shape in the finished bag, a first folding subseal 8 is provided which extends from the intersection 8a of the bottom transverse seal 12 with middle accordion folding longitudinal edge 4, 4a to the outer accordion folding longitudinal edge 8601274 4 -2-2.

In the flat-lying position, another second accordion folding sub-weld 9 lies under this weld, which proceeds in the same manner as the accordion folding sub-weld 8.

On the other side of the bag, similar first accordion folding sub-welds 10, 11 extend between the intersection 8b of the bottom transverse weld 12 with the middle accordion folding longitudinal edge 4a and a point on one of the outer accordion folding longitudinal edges 2a, 3a. Advantageously, the first accordion folding part-10 welds 8, 9, 10, 11 run at an angle of 45 ° to the outer accordion folding longitudinal edges.

At the other end, the bag is provided with second accordion folding part welds 13, 14 which extend from the outer accordion folding longitudinal edges 2 and 3 to 15, respectively, on the central accordion folding longitudinal edge 4, while the welds 15 and 16 extend from the accordion folding longitudinal edges 2a and 3a, respectively, to the middle accordion folding longitudinal edge 4a.

The second accordion folding sub-welds 13, 14 and 15, 16 expediently extend at an angle of 45 ° with the extension of the line connecting the end points 17 and 18 of said four second folding sub-welds.

According to the invention the plastic bag is provided with additional welds 30 which run parallel to the tube-foil axis and in the vicinity of the middle accordion folding longitudinal edges 4, 4a. Near means that the distance from an additional splice to the nearest center accordion folding longitudinal edge is about 2 to 10% of the distance between the center accordion folding longitudinal edge 4, 4a and the closest-30 outer accordion folding longitudinal edges 2, 3; 2a, 3a.

The additional welds are also connected to the inward ends of the second folding welds 13, 14, 15, 16.

The inner ends of the first folding part welds 8, 9, 35, 10, 11 are also connected to additional welds 13.

Figure 2 shows an embodiment in which a plurality of bags 27 are combined into a web, in which the top foil web 1a is cut between successive bags to form a cut 28, while the other side of the bag is perforated or superficial cut 29. In this way it is easy to separate a bag 27 with an open end from such a web, while on the other hand the delivery of the plastic bags in the form of a web makes it possible to deliver this web in coiled form, as a result of which the bags to be filled cannot slide past each other during transport and therefore a stack of such bags falls apart.

Figure 3 shows the first phase of forming a web of several interconnected plastic bags according to the invention. For this purpose, the track is provided with first and second accordion folding sub-welds 8, 9, 10, 11 and 13, 14, 15, 15 16.

In order to prevent welding of, for example, accordion folding part 5a to accordion folding part 6a, a separating means 26, for example a pertinax plate, is arranged between the accordion folding parts 5a and 6a. The heat seals 25a, 25b 20 will then form the desired accordion folding part welds. The additional welds 30 are also applied.

The foil web is then displaced by a distance A and a bottom transverse weld 12 is formed, while at the same time in the subsequent part of the foil web first and second side fold partial welds as well as additional welds 30 are applied.

To form the bottom cross weld 12, the foil layer parts 1a and 1b as well as the side fold parts 5a, 6a, 5, 6 are welded together for which use is made of a support 19 and a welding rod 20. However, it will be clear that the support 19 can also be heated may have been carried out.

Between successive bags, the top film web 1a / dxxsr is cut to form a cut 28 while the other side of the bag is provided with a perforation or superficial cut 29 to easily separate a bag from the resulting web.

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To form a bottom cross weld 12, first bottom cross weld folding part welds 21, 22 and 23, 24 are formed, each of which has an outer foil layer 1a, respectively. 1b with only the opposite accordion folding part 6, 6a resp. 5, 5a. These welds 21, 5, 22 and 23, 24 are formed simultaneously with the first and second folding part welds as well as additional welds.

When welding the film layers 1a, 1b together, the welds 21, 22 and 23, 24 are also joined together to form the bottom cross weld 12.

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Claims (7)

1A are connected to additional welds that extend to at least the bottom cross weld (12). Plastic bag with a side fold on both sides, each side fold comprising a middle and two outer accordion folding longitudinal edges defining a first and a second accordion folding part, the bag comprising the following parts: 5 a) a bottom transverse seal b) two first accordion folding sub-welds on both sides of the bag, the first accordion folding sub-welds always joining an outer foil layer to the opposite accordion folding part and the first accordion folding sub-welds extend between the middle and the outer accordion longitudinal edges in the region of the bottom transverse seal and from the bottom transverse edge to the outer folding edges diverge; c) two second accordion folding sub-welds on both sides of the bag, wherein the second accordion folding sub-welds always connect an outer foil layer with an opposite accordion folding part and the second accordion folding sub-welds extend between the middle and the outer accordion folding longitudinal edges, at the end of the bag and at a distance from the bottom transverse weld the two accordion folding part welds converging from the outer 20 longitudinal folding edges to the open mouth of a bag, characterized in that additional welds (30) are substantially parallel to the folding edges and in the region between the inner and outer accordion folding longitudinal edges on both sides of extend a bag, the additional seals (30) being connected to the second folding seals (13, 14; 15, 16) and extending from the second accordion folding seals toward the open end of a bag. Plastic bag according to claim 1, characterized in that the additional welds (30) extend in the vicinity of the inner folding edges (4, 4a). Plastic bag according to claim 1 or 2, characterized in that the additional welds extend to a filling opening (28) of the bag. Plastic bag according to Claims 1 to 3, characterized in that the first accordion folding part welds also include 8601274-8_ Plastic bag according to claim 4, characterized in that the additional welds (30) run on both sides of a bottom cross weld (12). Plastic bag according to claims 1-5, characterized in that a plurality of bags (27) are combined into a web which is provided with wall weakening (29) for separating a bag (27) with an open end from the web. 7. Apparatus for manufacturing a plastic bag according to one or more of the preceding claims, comprising at least transport devices for the stepwise transport of a plastic foil, first welding members for forming first accordion folding part welds, second welding members for forming second accordion folding part welds and cross welding devices for forming a bottom cross weld, characterized in that the device comprises fourth weld members for forming additional welds (30). 860.1 2 74