EP3246266B1 - Method for producing a side folding bag and flat lying, unfilled gusseted bag - Google Patents

Description

The invention relates to a method for producing a gusseted bag, wherein a material web of a bag film is guided in a direction of production, wherein folded gusset tube with a first front wall, a second front wall and arranged therebetween, the front walls connecting side gussets is formed by folding the bag film, and wherein the side gusset tube individual gusseted bags are separated.

The invention further relates to a flat, unfilled gusseted bag according to the preamble of claim 8, which can be formed in particular by the aforementioned method.

The gusseted bag is usually formed from plastic film, wherein in particular multilayer laminated films for the production come into consideration, in which case the films on an inside of the gusseted bag have a heat-sealable inner layer and an outer surface of the side gusseted bag forming outer layer, wherein in a laminated film and an internal Overprint may be provided, which is produced before laminating.

In the context of the invention, one of the two gussets can be provided with the reclosing device, with which the gusset can be fixed and closed in a folded state between the front walls, wherein the gusset can be folded outwardly by opening the reclosing device to a chute form. Usually, a transversely extending top seal seam is provided above the reclosing device in a filled gusseted bag, the must first be partially demolished, cut or peeled for a first opening with a corresponding head section.

Side gusseted bags as well as methods of manufacture are made of EP 1 620 321 B1 . EP 1 948 527 B1 . EP 2 032 454 B1 and EP 2 148 820 B1 known.

Known from this prior art gusseted bags have a reclosure with a single self-locking reclosure strip on the inside of the bag at a gusset and adjacent the gusset also extends to the two front walls and which connects the gusset with the two front walls. Starting from a center line of the gusset one wing, so one half of the corresponding gusset with the first front wall and the other half of the gusset is connected to the second front wall.

The length of the reclosure strip on the two front walls can be different according to the prior art as well as in the context of the invention. In particular, the reclosing strip on the front walls can also extend beyond the corresponding gusset, so that then adjacent to the gusset, the two front walls are directly connected to each other, whereby a larger discharge opening is provided. However, it is always envisaged that the reclosure extends only over part of the entire width of the front walls. Expediently, a connection line extending in the longitudinal direction of the bag or in the transverse direction of the bag, in particular a heat-sealing seam, can be provided laterally to the reclosing strip in order to delimit the opening.

For the production of gusseted bags, various methods are known in practice. In the generic method, the front walls and the side folds are formed by folding from a single film web. From a gusseted tube with the front walls and the side gusses individual gusseted bags or corresponding blanks are then separated, each having a reclosing device.

Because the direction of production of the web or gusseted tube is the same as the longitudinal direction of the gussets, the corresponding methods are also referred to as "longitudinal methods".

Individual gusseted pouches are then separated from the gusseted tubing, wherein a filling can take place directly in this case, which is then a so-called FFS process (Form Fill and Seal). Alternatively, prefabricated gusseted bags can first be formed which are not yet closed on at least one side and can then initially be stored and transported to a packaging location. Such gusseted bags are then filled separately and sealed.

From practice, alternative manufacturing methods are known in which the front walls and the gussets are formed from separate film sections. That's how it describes EP 1 541 332 A1 a method for the production of film packaging bags, in which a bag string is formed such that successive foil packaging bags are arranged side by side with their bag longitudinal edges. The production direction thus corresponds to a bag transverse direction of the individual bags, which is why such a method is also referred to as a "transverse method" or as a "Totani method".

According to EP 1 541 332 A1 First, a bag string of successive, connected bag blanks is formed. A first film web is guided in the production direction. Thereafter, a film strip is fed, wherein the edges of the film strip are folded over on a central portion. The edges are usually the same width, with a gap remaining between the edges after folding. Subsequently, pieces of film strips are applied at a uniform distance transversely to the production direction (ie along the bag longitudinal direction) on the first film web before a second film web is fed in the production direction, with which the first film web and the pieces of film strips are covered. Then longitudinal sealing seams are produced transversely to the direction of production, with which the film strips are welded on the one hand at the folded edges with the second film web and on the other hand on an opposite side with the first film web. From the thus formed bag strand, individual foil packaging bags are finally separated by a cut in the region of the foil strips in such a way that two side folds of successive side fold bags are formed from a folded foil strip. In addition to the gussets, a separate bottom fold can be produced as a flat bottom.

In such a transverse method, it is readily possible to perform the gussets shorter than the two front walls, so that a continuous reclosure can be arranged above the gussets, which connects only the two front walls together. The arrangement of a reclosure in the range of one of the gussets, with the corresponding gusset can be folded out as a chute, however, is not useful with the described cross-method, because to form the two front walls and the gussets separate pieces of film fed and subsequently connected, wherein then the integration of a reclosure at one of the gussets and the associated sections of the front walls by conventional technical means is not possible.

In order to produce a bottom in the generic method for producing a gusseted bag, a lower edge of the gusseted bag can be closed with a transverse sealing seam, but then a uniform placement of the gusseted bag is not possible. Rather, such a gusseted bag tends during filling, its transport and its storage to a tilt when it is to be placed on its lower portion as a floor.

To reduce this tendency to tilt, it is known to first seal a lower portion of the gusseted bag with a transverse seam and then fold it onto itself, thereby forming a type of reinforced double-walled bottom. However, this procedure is disadvantageous insofar as it requires a further work step for the folding over, whereby an increased material requirement also results from the folding of the lower section on itself. Finally, the folding of the end portion in one direction leaves a certain asymmetry, so that an inclination can not be completely avoided. The additional generation of Eckabsiegelungen or the like can not completely solve the problem described.

From the DE 10 2008 021 505 A1 a method for producing a gusseted bag is known, wherein a web of material is supplied to a bag film in a production direction, wherein folds of the bag film, a gusseted tube with a first front wall, a second front wall and arranged therebetween, the front walls connecting gussets is formed and wherein of the gusseted tube individual gusseted bags are separated. In the bag film is for each gusseted bag in creates a transverse weakening line which extends in the subsequently formed gusseted tube over both gussets and the first front wall which is arranged between the side gussets. Then, when the weakening is torn at the gusseted tube, the first front wall is raised and at least partially folded, whereby the underlying second front wall and the side gussets are exposed in sections. To form a flat bottom, a separate foil section is prefixed to the folded-over section of the first front wall and the second front wall as well as to the side folds, before the folded-over section is then folded back again. Finally, the bottom fold forming separate film section is completely sealed before then a separation takes place.

Against this background, the invention has for its object to provide a method for producing a gusseted bag, the gusseted bag should have a good stability and a high-quality appearance. Furthermore, it is also intended to specify a flat, unfilled gusseted bag with a reclosing device, which can be produced in particular in the method according to the invention.

The invention and solution of the problem are a method for producing a gusseted bag according to claim 1 and a flat, unfilled gusseted bag according to claim 8.

• dass in der Beutelfolie für jeden Seitenfaltenbeutel ein in einer Querrichtung verlaufender Einschnitt derart erzeugt wird, dass sich der Einschnitt bei dem Seitenfaltenschlauch über beide Seitenfalten und die erste Frontwand erstreckt, welche zwischen den Seitenfalten angeordnet ist,
• dass bei dem Seitenfaltenschlauch die durch den Einschnitt aufgetrennte erste Frontwand an einer Seite des Einschnittes angehoben und zumindest teilweise umgeklappt wird, wodurch die darunterliegende zweite Frontwand sowie die Seitenfalten abschnittsweise freigelegt werden,
• dass zur Bildung eines Flachbodens ein separater Folienabschnitt über erste Verbindungsnähte mit dem umgeklappten Abschnitt der ersten Frontwand und der zweiten Frontwand und mit zweiten Verbindungsnähten an den freigelegten Seitenfalten verbunden wird und
• dass der umgeklappte Abschnitt derart zurückgefaltet wird, dass die zweiten Verbindungsnähte parallel zu den ersten Verbindungsnähten in Querrichtung verlaufen.

In the method according to the invention is therefore provided

• that in the bag film for each gusseted bag, a transverse incision is made in such a way that the Incision in the gusseted tube extending over both gussets and the first front wall which is disposed between the gussets,
• in the gusseted tube, the first front wall separated by the incision is raised at one side of the incision and at least partly folded over, whereby the underlying second front wall and the side folds are exposed in sections,
• in that, to form a flat bottom, a separate foil section is connected via first connecting seams to the folded-over section of the first front wall and the second front wall and to second connecting seams on the exposed side folds, and
• in that the folded-over section is folded back in such a way that the second connecting seams extend transversely parallel to the first connecting seams.

The gusseted bag is usually printed on all bag surfaces, ie on its front walls, its side gussets and also the separate film section as a bottom on the outside of the bag or provided with a visible on the outside of the bag inside print. On the other hand, the inner surfaces of the gusseted bag are formed by a sealable layer, which is usually monochrome, in particular white.

When arranging the separate film section, it should be noted that, due to size and positional deviation, the latter partially overhangs the surfaces of the front walls and side folds arranged underneath or can jump back. Without further measures, this would mean that the inner side surfaces of the bag in sections of the finished gusset bag are visible as so-called "speed cameras", whereby the visual appearance of the gusseted bag is considerably impaired.

In order to avoid such speed cameras, the foil section and the lower edges of the front walls and gussets are trimmed within the scope of the invention, this trimming preferably taking place simultaneously with the separation of individual gusseted bags from the gusseted tube.

In this connection, the method according to the invention is carried out in such a way that, when the folded-over section is folded back, the second connecting seams, with which the separate film section is connected to the side folds, run transversely parallel to the first connecting seams, for which purpose the folding back is suitably controlled got to. When folded back along a straight line, the separate film portion would extend along the first transverse seams and along the second longitudinal seam joints of the gusseted tube, including, as appropriate, trimming to avoid "flare" in both the transverse and longitudinal gusseted tubing would.

According to the invention, however, the folding back is performed and controlled so that the gussets are inserted over their entire length again between the front walls, whereby then the separate film section in the gussets multilayer is superposed, so that then the lower end of the gussets again in line with the lower ends of the front walls, so that there also the first connecting seams and the second connecting seams together by a single cut in Transverse can be cropped. This pruning is also called pruning.

Particularly preferred for the trimming and the separation of the individual side gusseted bag a double cut along two transverse cutting lines is performed. Below the separate foil section provided as a bottom, a first cut line of the double cut forms the upper edge of the subsequent bag. As a result of the second cut of the double cut, so much material is removed in the region of the separate film section that the previously described "blitzers" are completely separated even in the case of dimensional and positional deviations.

The distance between the two cutting lines of the double cut can be, for example, between 1 mm and 20 mm, in particular between 2 mm and 10 mm.

The incisions may conveniently be formed in the still flat web of material, but then in the folding then tearing must be prevented and the web is to be guided with appropriate care. In principle, it would also be conceivable to provide only a weakening line or perforation on the material web, which is then subsequently separated further.

According to a preferred embodiment of the method it is provided that are arranged on the web at a uniform distance and at a uniform distance to the incisions transverse to the direction of production reclosing strip, which after forming the gusseted tube at one of the gussets and each over a part extend the two front walls, in which case under the According to the invention method of the gusseted bag described below is formed with a reclosure at the first gusset.

The reclosure strip expediently extends at the front walls at least over a width which corresponds to half the width of the associated gusset. In such an embodiment, only a connection of the two wings of the gusset with one of the front walls takes place. If the reclosure is carried out beyond the gusset area, the two front walls can also be connected directly to each other in certain areas.

At least, however, the reclosure strip extends in all cases only over part of the front walls.

In a further aspect, the method can also be used to attach carrying handles which are expediently arranged on the side fold which lies opposite the reclosable strip.

Usually, for each bag exactly one carrying handle and exactly one reclosure strip attached. While the reclosure strips are attached to the inner layer of the bag film, the carrying handle must also be accessible from the outside. Various suitable handle constellations are from the EP 2 148 820 B1 known.

In order to close the gusseted tube on the circumferential side, a heat-sealing seam may be provided, wherein such a heat-sealing seam is preferably formed in the region of one of the side edges. In principle, all side edges can be provided with a heat-sealing seam in order to improve the stability of the side gusset bags that are formed. If the material web at a Side edge is welded to a circumferentially closed tube, supernatants can be provided there, which trimmed, that is cut off.

The first front wall is preferably folded over at a fold line spaced from the incision in such a way that the distance of the fold line from the incision corresponds approximately to half the width of the side fold. The front wall is then folded as far as possible, whereby the exposed gusset, starting from a central crease line at an oblique angle of 45 ° to the outside.

The separate sheet section for forming a flat bottom for each gusseted bag is conveniently attached to the front panels and gussets with heat seal sutures. The sealing at the gussets can be done easily on the flattened gusseted tube. The same applies to the connection of the separate film section with the exposed second front wall. In order to avoid an undesired sealing when connecting the separate film section with the folded-up edge of the first front wall within the gusseted tube, the corresponding generation of a transverse sealing seam is preferably carried out in the raised state.

The invention is also a flat, unfilled gusseted bag with two opposite front walls, a first and a second gusset, which extend opposite each other along a bag longitudinal direction and each connect the two front walls together. Preferably, a reclosing device having at least one reclosable strip is provided, which is arranged in the region of the first gusset, only along a transverse direction of the bag extends over a portion of the width of the front walls and allows the folding out of the first gusset to form a resealable chute. The flat-lying, unfilled gusseted bag is produced in particular by the manufacturing method described above, wherein a separate film section is provided for forming a flat bottom, characterized in that the film section is connected via first heat-sealed seams to lower ends of the front walls and via second heat-sealing seams to lower ends of the gussets wherein the film portion is disposed between the front walls such that the first heat-sealing seams and the second heat-sealing seams are arranged parallel to each other along the bag transverse direction.

By this arrangement, it is possible, in the formation of the flat, unfilled gusseted bag, to trim all edges of the separate film section or parts of the front and gussets connected thereto by a single transverse cut in the bag transverse direction, to remove any overhangs and "blotter" produced thereby. to eliminate.

By providing a reclosure at a gusset to form a fold-out chute on the one hand and a flat bottom in the form of a separate film section on the other hand, particularly advantageous measures are combined according to the invention, which could be realized according to the prior art only in different bag-making process and thus could not be combined.

The gusseted bag according to the invention is characterized by a particularly advantageous handling. With the aid of the reclosing device at the first gusset this can after a first opening in a folded State are fixed, in which case the two wings of the first gusset are each attached to one of the two front walls. By loosening the reclosure then the gusset can be folded outwards to form a chute, so that then a particularly easy and accurate dosage is possible. In particular, the gusseted bag can be emptied controlled by an inclination by a user, with just a precise removal of subsets is possible, in which case the remaining contents is protected by the reclosing device.

With regard to the arrangement and design of the reclosing device can on the known from the prior art embodiments, in particular to embodiments according to EP 1 620 321 B1 . EP 1 948 527 B1 . EP 2 032 454 B1 and EP 2 148 820 B1 be resorted to.

The gusseted bag may for example have a filling volume between 1 l and 50 l, in particular between 2 l and 30 l. The gusseted bag is particularly suitable for receiving bulk materials such as pelleted pet food, detergent, cat litter, road salt and powdery or granular construction materials.

In order to ensure a reliable closure, a top seal seam is usually provided above the reclosing device prior to initial opening, which seals the side gusset bag tightly. For initial opening, at least a portion of the bag head formed by a top seal is then torn off to expose the underlying recloser and allow the chute to fold out and reclosure.

The reclosing device comprises at least one reclosing strip, which preferably runs exactly in the transverse direction of the bag. in principle it is possible that the reclosing device has a plurality of separate reclosing strips which are lockable with each other. According to a preferred embodiment of the invention, however, it is provided that the reclosing device has a single, continuous and self-locking reclosable strip. Such a reclosing strip can be particularly easily placed on a flat web of material during manufacture, in which case only folding of these reclosing strip in the desired position on the gusset is arranged.

With regard to the specific embodiment of the reclosure strip, different possibilities arise within the scope of the invention. Even if a reclosing strip on the basis of adhesive is not excluded, preferably a mechanical locking takes place. To achieve a mechanical interlock, the reclosing strip may have either continuous closure formations or a plurality of individual interlockable closure elements. For example, grooves, protrusions and hook-shaped curved strips which can be locked together or with themselves can be considered as continuous closure molding. Corresponding structures can be extruded, for example, as a strand, wherein the closure formations are usually arranged on a heat-sealable support section or extruded in one piece with the heat-sealable support section.

Individual, lockable closure elements can be provided for example in the form of Velcro hooks, mushroom heads or the like. In the case of individual closure elements which can be locked together, there is the advantage that secure locking is possible even with a vertical offset. The individual mushroom heads or Velcro hooks are usually so mobile, that they can penetrate at a pressure from the outside in an associated space and then lock there with similar closure elements. In the case of individual closure elements which can be locked together, there is also the advantage that, although contaminants locally avoid a connection, the entire reclosure strip can not be easily pulled up from the dirt.

According to a preferred embodiment of the invention, the front walls and the side folds are formed from a bag film, in particular a uniform bag film, wherein the front walls and the side folds can be folded from a uniform material web as described above. The bag film usually has at least one heat-sealable inner layer and one outer layer, wherein the assignment of the inner layer and the outer layer relates to the arrangement of the bag film on the side-folding bag. The inner layer thus forms the inner surface of the gusseted bag, while the outer layer forms the outer surface.

The inner layer is expediently well heat-sealable in order to close the pouch on the circumference, to be able to form longitudinal and transverse sealing seams and also to be able to fasten further devices such as the reclosing device by heat sealing. In addition to polyolefins such as polyethylene (PE) and polypropylene (PP) and polyolefin copolymers, biodegradable plastics such as polylactic acid (PLA), polybutylene adipate terephthalate (PBAT) and polybutylene succinate (PBS) are also suitable as the heat-sealable material for the inner layer.

The outer layer is less heat sealable compared to the inner layer, for which the outer layer may have a higher melting or softening temperature. In a heat-sealing of the bag film is then achieved that although the inner layer - possibly through the outer layer therethrough - is melted, but without causing the outer layer is excessively deformed or loses its structure. The outer layer may in particular be formed from polyester. A reduction in the tendency to melt in a heat seal can also be achieved by an orientation of the outer layer. For the outer layer therefore also oriented polyethylene terephthalate (OPET), oriented polyamide (OPA), oriented polypropylene (OPP) and oriented polylactic acid (OPLA) into consideration. In addition, the outer layer may also be formed by a cellulose film.

According to a preferred embodiment of the invention, a laminating film is used as the bag film, wherein a first film with the inner layer and at least one second film with the outer layer are bonded together by adhesive. Suitable, for example, is a two-component adhesive based on polyurethane (2K-PUR). Finally, other intermediate layers may be provided, for example to increase the barrier effect. As a barrier, for example, a film layer of ethylene-vinyl alcohol copolymer (EVOH) may be provided a thin metal foil or a metallized film layer.

In the case of a laminated film, an internal printing is preferably also provided, which is applied to one of the joining surfaces of the films to be joined together before laminating.

As already explained above, the gusseted bag is expediently produced in a longitudinal method, wherein a material web of the bag film is first converted into a gusseted tube, from which individual side gusset bags are then separated.

Accordingly, it is provided according to a preferred embodiment of the invention that at least a part of the side edges formed between the side folds and front walls are formed as folded edges. In order to be able to close the gusset tube on the circumference in the manufacture, a longitudinal seal is expediently carried out. This can coincide with one of the side edges, so that then this side edge is not formed as a folding edge. In addition, the edges of the material web can also be connected to one of the front surfaces by a longitudinal seam.

Even if at least a part of the side edges are formed as folded edges, the production of longitudinal sealing seams at the side edges may be expedient in order to increase the dimensional stability and dimensional stability of the gusseted bag. After forming longitudinal sutures, an outer edge may also be cut to improve the appearance.

An upper edge of the bag above the reclosing device is usually closed by a transverse sealing seam. In the context of such an embodiment, it is preferably provided that the side folds extend over the entire side gusseted bag from the flat bottom to the transverse seam at the upper edge of the bag, that is to say in the longitudinal direction of the bag. Further measures to shorten the gusset are then not necessary.

Particularly in the case of a large filling volume and / or a large filling weight, the gusseted bag can be provided with a carrying handle. The carrying handle can be like from the EP 2 032 454 B1 be stamped on the bag head in a sealed area. According to a preferred embodiment of the invention, however, the second gusset on a carrying handle, which then faces the reclosing device. Suitable embodiments of carrying handles are off EP 2 148 820 B1 known. While the reclosing means is desirably located near an upper end of the gusseted bag, the carrying handle may be staggered approximately midway or slightly offset with respect to the flat bottom of the gusseted bag with respect to the bag longitudinal direction, whereby then the weight of the gusseted bag can be easily controlled even when dispensed.

The flat bottom provided according to the invention by a separate film section usually has a heat-sealable inner layer and an outer layer, as described above, wherein the flat bottom can also be formed from the previously described bag film. The flat bottom usually has a rectangular shape, wherein the length and width of the film section corresponds to the width of the front walls and the width of the side folds.

Through the flat bottom of the gusseted bag can be placed straight. This is advantageous both in the filling, transport, storage and handling of the gusseted bag. In contrast to a merely turned over hose section to form a stand, in addition to the improved handling, there is even a saving of material, because several film layers do not have to be arranged one above the other.

Fig. 1

einen Seitenfaltenbeutel im befüllten Zustand in einer perspektivischen Ansicht,

Fig. 2

den Seitenfaltenbeutel gemäß der Fig. 1 in einem unbefüllten, flachgelegten Zustand,

Fig. 3a bis 3f

Verfahrensschritte zur Herstellung des in Fig. 1 und Fig. 2 dargestellten Seitenfaltenbeutels.

The invention will be explained in the following with reference to a drawing showing only one exemplary embodiment. Show it:

Fig. 1

a gusseted bag in the filled state in a perspective view,

Fig. 2

the gusseted bag according to Fig. 1 in an unfilled, flattened state,

Fig. 3a to 3f

Process steps for the preparation of in Fig. 1 and Fig. 2 illustrated gusseted bag.

The Fig. 1 shows a gusseted bag with two opposite front walls 1a, 1b, a first gusset 2a and a second gusset 2b, wherein the gussets 2a, 2b extend opposite each other along a bag longitudinal direction l and each connect the two front walls 1a, 1b with each other.

While the Fig. 1 shows a filled and sealed in a transverse direction of the bag q by a head seal 3 side gusseted bag shows Fig. 2 a flat-lying, unfilled gusseted bag according to the invention, which is provided as a prefabricated bag (pre-made bag) in a flat state for a subsequent filling. To start from the Fig. 2 to the filled bag according to the Fig. 1 to arrive, the prefabricated, flattened bag is filled at the top initially not yet closed edge and closed by the head seal 3. The side edges between the front walls 1a, 1b and the side folds 2a, 2b are reinforced by longitudinal sealing seams 4.

From the Fig. 1 and 2 As a result, the bag has a reclosing device with a reclosing strip 6. The reclosing strip 6 is arranged in the region of the first side fold 2a and extends over the two wings of the first side fold 2a inserted between the front walls 1a, 1b and along the front walls 1a, 1b. In the illustrated embodiment, the reclosure strip 6 extends on the front walls 1a, 1b beyond the first side fold 2a, so that the two front walls 1a, 1b can also be directly connected to one another in an area adjoining the first side fold 2a. In contrast, in the area of the first side fold 2a, the two wings of the corresponding side fold 2a are connected to one of the two front walls 1a and 1b, respectively.

To open the gusseted bag for the first time, a weakening line 7 is arranged above the reclosure strip 6, with which a corner section 8 above the reclosure strip 6 can be separated. The weakening line 7 can be formed for example by a punching, a perforation or a laser, wherein the various measures can also be combined. For crack initiation also a notch 9 is provided.

In order to allow a sufficient closure of the side gusset bag after a first opening, a transverse seam 10 is formed adjacent to the reclosure strip 6, which extends from the end of the reclosure strip 6 to the opposite edge of the bag.

After opening for the first time, the first gusset 2a can be folded outward by opening the reclosing device formed by the reclosing strip 6, forming a chute, and reinserting between the two front walls 1a, 1b for a new closure.

According to the invention, the gusseted bag has a flat bottom which is formed by a separate film section 11. The film portion 11 is connected to the lower edges of the front walls 1a, 1b and the side folds 2a, 2b by heat sealing seams 12a, 12b. While the flat bottom during filling, the transport, storage and handling is particularly advantageous and allows a safe deployment of the gusseted bag, the contents can be easily removed with the reclosing device, in particular, the removal of subsets by the formation of a chute is exactly possible.

Depending on the filling weight of the gusseted bag can also be equipped with a carrying handle, not shown, which is suitably arranged on the second side fold 2b, which is opposite to the reclosing device.

The reclosing strip 6 may comprise continuous closure formations in the form of grooves or projections or also a multiplicity of individual closure elements which can be locked together, wherein such individual closure elements which can be locked together may for example have the form of mushroom heads or hooked hooks.

From the Fig. 2 it can be seen that the gussets 2a, 2b extend over the entire length of the front walls 1a, 1b and are not folded over in the region of the separate film section 11 to the outside. On the contrary, the separate film section in the area of the side folds 2a, 2b is folded back on itself in such a way that all the heat sealing seams 12a, 12b provided for the connection of the film section on the one hand to the front walls and on the other hand for the connection of the film section 11 to the side folds 2a, 2b Bag transverse direction q run over each other and can be trimmed together in order to remove by dimensional and positional deviations resulting supernatants.

A preferred method for the preparation of in the Fig. 1 and 2 shown gusseted bag is in the Fig. 3a to 3f shown.

In the method, a material web is fed to a bag film 13 in a production direction p, which corresponds in its orientation to the bag longitudinal direction l. The corresponding method is therefore also referred to as a longitudinal method.

In a conventional manner is according to the Fig. 3a by folding the bag film 13, a gusseted tube 14 is formed, which has a first front wall 1a, a second front wall 1b and two side folds 2a, 2b connecting the front walls 1a, 1b. According to the Fig. 3a the crease lines are already indicated.

Outer edges 15 of the bag film 13 are provided as a projection and are separated after the formation of the gusseted tube 14.

According to the Fig. 3a For example, in the bag film 13, for each gusseted bag prior to folding, a transverse incision 16 is made such that the incision 16 in the subsequently formed gusseted tube 14 extends over the two gussets 2a, 2b and the first front wall 1a which extends between the gussets 2a, 2b is arranged. As will be explained in detail below, the individual gusset bags are separated from the gusseted tube 14 in the region of the incisions 16, wherein the incision 16 is provided for the formation of a flat bottom.

Alternatively, it is in modification to the Fig. 3A also possible to first form a gusseted tube 14 and only then the incisions 16 to produce. The gusseted tube 14 can be pulled, for example, over a kind of core, which is then provided for generating the incisions 16, for example by punching, as a kind of abutment. In principle, the incisions 16 can also be formed after the formation of a gusseted tube with a laser or a particularly precise punching, whereby a complete transection of the gusseted tube is always to be avoided.

The bag film 13 is at least two-layered and comprises a heat-sealable inner layer of polyolefin, in particular polyethylene and an outer layer of polyester, in particular PET. The film section 11 may be formed of a same or similar material with a corresponding layer structure. The heat-sealable inner layer is according to Fig. 3a at the flat-fed bag film 13 initially free, so that there can also be sealed for each gusseted bag a transverse reclosing strip 6. Adjacent to the reclosing strip 6, the weakening line 7 is also already produced in the flat bag film 13, with which the upper corner section 8 for exposing the reclosable strip 6 during a first opening can subsequently be separated in the finished gusseted bag.

Since the sipes 16 extend over the first front wall 1a and both side gussets 2a, 2b, the first front wall 1a can be raised, for which purpose, for example, grippers or vacuum cups can be used.

In the Fig. 3A is further indicated also that in the formation of the gusseted tube 14 also longitudinal sealing seams 4 can be generated. If now at the incisions 16, the overhead first front wall 1a is partially folded, including the two side folds 2a, 2b and the second front wall 1b partially exposed (see Fig. 3b ), whereby then there the side folds 2a, 2b, starting from a bend line 17 at an angle of 45 ° to the outside. On the so folded along the fold line 17 foot area a separate film section 11 is placed, which according to the Fig. 3b in particular can be supplied laterally.

According to the embodiment according to Fig. 3A the gusseted tube is moved in such a way that, based on the individual foil bags to be separated from the gusseted tube 14, the bottom region lies in front of the head region. In principle, however, the production of the foil pouches can also take place in such a way that the production direction is exactly the opposite with respect to the upper edge and the lower edge of the lateral fold pouches to be formed, so that after the side fold tube 14 has been formed from the pouch foil 13 relative to the individual side fold pouches to be formed the head is in the direction of production p forward. Such a reverse direction may be advantageous in order to fold back the folded-over section in the context of the invention in such a way that the second connecting seams run parallel to the first connecting seams in the transverse direction q. Based on the following described in detail Fig. 3E would then also result in a reversal of the production direction p, so that in the region of the separate film section 11 indicated by an arrow folding back the gussets 2a, 2b can be made easier.

According to the Fig. 3c this separate film section 11 is connected to the unfolded gussets with heat sealing seams 12b, wherein this heat sealing can be done with a flat gusseted hose 14.

In order to connect the separate film section 11 to the first front wall 1a, the undesired generation of a heat-sealed seam within the To avoid gusseted tube 14, according to the Fig. 3d be provided that the folded-over portion of the first front wall 1a is erected and then connected in the erected state along a heat-sealing seam 12a with the separate film section 11 ( Fig. 3e ).

Like in the Fig. 3e 1, the previously folded-over portion is folded back such that the second heat-sealing seams 12b are placed on the lower edge by inwardly buckling the separate film portion 11 on themselves, then finally the first heat-sealing seams 12a and the second heat-sealing seams 12b are superimposed. In the Fig. 3f In this context, it is indicated that, on the one hand, the individual successive flat, unfilled gusseted bags are separated from each other by a double cut D and an outer edge is severed at the first and second heat sealing seams 12a, 12b in order to remove any overhangs and associated "speed cameras" (see also Fig. 2 ).

Claims (12)

1. A method for producing a side-gusseted bag,
   wherein a material web of a bag film (13) is supplied in a production direction (p);
   wherein by folding the bag film (13) a side-gusseted tube (14) comprising a first front wall (1a), a second front wall (1b) and side gussets (2a, 2b), which are disposed between and connect the front walls (1a, 1b) is formed and
   wherein individual side-gusseted bags are separated from the side-gusseted tube (14),
   wherein an incision (16) extending in a transverse direction is produced in the bag film (13) for each side-gusseted bag such that, in the side-gusseted tube (14), the incision (16) extends over both side gussets (2a, 2b) and the first front wall (1a), which is situated between the side gussets (2a, 2b),
   wherein in the side-gusseted tube (14), the first front wall (1a), which is separated by the incision (16), is lifted on one side of the incision (16) and is at least partially folded over, whereby the underlying second front wall (1b) and the side gussets (2a, 2b) are exposed in sections,
   wherein to form a flat base, a separate film section (11) is connected via first connecting seams to the folded-over section of the first front wall (1a) and the second front wall (1b) and via second connecting seams to the exposed side gussets (2a, 2b), and
   wherein the folded-over section is folded back in such a way that the second connecting seams extend in parallel to the first connecting seams in the transverse direction.
2. The method according to claim 1, wherein the edges of the separate film section, and the lower edges of the front walls and side gussets are trimmed during the separation of individual side-gusseted bags from the side-gusseted tube (14).
3. The method according to claim 2, wherein a double cut is made along two cutting lines extending in the transverse direction for trimming and separating the individual side-gusseted bags.
4. The method according to one of claims 1 to 3, wherein reclosure strips (6) extending transversely to the production direction (p) are arranged on the material web with uniform spacing, which reclosure strips after the formation of the side-gusseted tube (14) extend on one of the side gussets (2a, 2b) and in each case over a portion of each of the two front walls (1a, 1b).
5. The method according to claim 4, wherein the side gusset positioned opposite the reclosure strip (6) in the side-gusseted tube (14) is provided with handles.
6. The method according to one of claims 1 to 5, wherein the side-gusseted tube (14) is closed around a circumference by means of a heat-sealing seam.
7. The method according to one of claims 1 to 6, wherein the separate film section (11) is fastened to the front walls (1a, 1b) and the side gussets (2a, 2b) by means of heat-sealing seams (12a, 12b).
8. A flat, unfilled side-gusseted bag, comprising two front walls (1a, 1b) positioned opposite each other, a first and a second side gusset (2a, 2b), which are positioned opposite each other, extend along a bag longitudinal direction (I) and connect the two front walls (1a, 1b) to each other, wherein a separate film section (11) is provided to form a flat base, characterized in that the film section (11) is connected via first heat-sealing seams (12a) to lower ends of the front walls (1a, 1b) and via second heat-sealing seams (12b) to lower ends of the side gussets (2a, 2b), wherein the film section (11) is arranged between the front walls (1a, 1b) in such a manner that the first heat-sealing seams (12a) and the second heat-sealing seams (12b) are arranged parallel to each other along the bag transverse direction (q).
9. The flat, unfilled side-gusseted bag according to claim 8, wherein the front walls (1a, 1b) and the side gussets (2a, 2b) are formed from a bag film (13).
10. The flat, unfilled side-gusseted bag according to claim 8 or 9, wherein at least one reclosure device comprising a reclosure strip (6) is provided, which reclosure device is arranged in the region of the first side gusset (2a), which extends along the bag transverse direction (q) across only a portion of a width of the front walls (1a, 1b) and allows the first side gusset (2a) to be folded outwards to form a reclosable spout.
11. The flat, unfilled side-gusseted bag according to claim 10, wherein an upper bag edge is closed above the reclosure device by a top sealing seam (3).
12. The flat, unfilled side-gusseted bag according to claim 11, wherein the side gussets (2a, 2b) extend from the flat base up to the top sealing seam (3) on the upper bag edge.

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