DE102017121981A1 - Film bag and method for forming foil bags - Google Patents

Abstract

The invention relates to a foil bag with two opposite rectangular front walls (1), with four side folds (2a, 2b, 2c, 2d) arranged between the front walls (1) and connecting the front walls (1) and with a filling opening (3) the front walls (1) and the lateral folds (2a, 2b, 2c, 2d) each have a sealing layer (5) on an inner side of the bag and an outer layer (6) on a bag outer side, the outer layer (6) having a higher softening temperature than the sealing layer ( 5) and wherein the front walls (1) are connected to the side folds (2a, 2b, 2c, 2d) arranged between them by means of heat-sealing seams (4 '). According to the invention, the filling opening (3) is formed at a first corner of the front walls (1) in that the side folds (2a, 2c) converging there are unconnected, while at the remaining corners of the front walls (1) the side folds (2a, 2b , 2c, 2d) are connected by a heat-sealing seam (4).

Description

The present invention relates to a foil bag with two opposing rectangular front walls, with four arranged between the front walls and the front walls connecting gussets and with a filling, wherein the front walls and the side folds each have on a bag inside a sealing layer and on a bag outside an outer layer, said Outer layer has a higher melting or softening temperature than the sealing layer and wherein the front walls are connected to the gussets arranged between them via heat sealing seams.

The layer structure described ensures that in the case of heat sealing at a suitable sealing temperature, only the inner sealing layer is melted and bonded to the adjacent film layer, while the outer layers of the layers, for example, are not connected to one another at the side folds. The specification of a higher melting temperature for the outer layer relates essentially to the realization of the described characteristics in the production of hot-sealing seams.

The invention is directed to initially unfilled as well as filled foil pouches. In the unfilled state, the foil bag is essentially laid flat, in which case the side folds are folded inwards under the front walls.

In the filled state, however, the side folds are unfolded and essentially form four side walls arranged at right angles around a circumference of the foil bag. The result is a cuboid shape, with one of the gussets is provided as a floor for most applications.

The cuboid shape results in an excellent stability of the film bag, wherein usually all sides of the cuboid shape are reinforced by heat-sealing seams. The cuboid shape also results in a particularly high-quality appearance with clearly visible and almost flat surfaces. During storage, transport and presentation of goods, the film bag can be tightly packed and stacked with a minimum of dead space due to its special cuboid design.

For a user, there is also the advantage that due to the cuboid shape, the filling level is also approximately proportional to the remaining material in the film bag, so that the film bag is also suitable for a partial removal of the contents over a longer period. Especially in this context, the particularly good stability is beneficial.

In the context of the invention, the film bag can therefore also be combined with spouts, reclosures or the like.

In the case of the film bag in question, however, this results in a relatively complicated production because of technical measures, because gussets must be inserted on all four sides of the front walls by means of suitable measures and, in particular, must also be connected to each other in a suitable manner.

A foil bag with the features described above is made GB 2 317 159 A known. To produce the film bag is provided according to a first variant to provide the two front panels and the four gussets as separate foil blanks, two of the gussets must be bent at their ends in a suitable manner be bent on itself in order to connect to the two adjacent side gussets become. According to a variant of the method, initially a gusseted tube with inserted gussets can be formed, in which case individual tube sections are separated and the further gussets are inserted at the ends of the tube sections.

Due to the relatively complex production, the integration in an automated manufacturing process is demanding. In particular, the design options are also limited. Accordingly, according to the cited prior art, a filling opening is provided on a front wall.

For pourable goods valve bags made of plastic and paper in various designs have long been known for comparatively large container sizes.

From the DE 66 05 249 U is a gusseted valve bag made of thermoplastic material known, wherein for the formation of the valve sack, starting from a piece of a gusseted tube by a complicated folding a bottom is formed. By a different folding a filling valve made of film can be used on a bag edge, with an automation of the relatively complex and especially on both sides different folding process is not readily possible. The soil formed by folding is not comparable with respect to its appearance and the stability with a substantially flat bottom formed by a separate foil sheet.

Also according to the DE 69 45 778 becomes a floor by folding and folding one formed uniform web, thereby a bag tube without side gussets can be integrated.

According to the EP 1 935 797 B1 . WO 2016/189541 A1 as well as the WO 2017/051431 A1 a cross-bottom is formed to form a valve bag made of film or plastic fabric, which in addition to folding the front walls in the bottom area a separate sheet is launched. By such a cross-bottom, an approximately rectangular base is created, the filled bag assume a typical shape in horizontal cross-section oval shape and thereby the stackability, the compact arrangement and the stability are affected by the further embodiment without gussets.

Against this background, the present invention seeks to provide a film packaging bag, which is characterized by good functional properties, a high-quality appearance and easy filling with pourable goods. Furthermore, a method for producing such a film bag is to be specified.

The invention and the solution of the problem are a film bag according to claim 1 and a method for forming film bags according to claim 10.

Proceeding from a generic foil bag, it is accordingly provided that the filling opening is formed at a first corner of the front walls in that the side folds converging there are unconnected, while at the other corners of the front walls the side folds converging there are connected by a heat-sealing seam. On the one hand, the present invention relates to an unfilled foil bag, in which the four side folds are usually inserted between the two front walls. When the film bag is filled through the filling opening, the side folds are then oriented and, when completely filled, form approximately planar surfaces, so that the film bag in the filled state has the shape of a cuboid.

As further described in detail, the filling opening can be closed according to a first embodiment of the invention after filling by suitable measures, which then results in optimal protection of the filled product. In addition to a completely dense configuration, the integration of vent valves or the like comes into consideration.

According to a further, preferred embodiment of the invention, a valve formed from a separating film is arranged at the filling opening, which can already avoid an outlet of the filling material contained in the film bag after filling. Depending on the requirement, it is then even possible to completely dispense with a further closure, so that then the features of claim 1 also relate to a filled foil pouch.

In the context of the present invention, the filling opening is located at a corner of the front walls, that is to say a side edge of the film bag which is cuboid in the filled state, between side gussets converging there.

The film bag according to the invention can be connected in a particularly simple manner to filling devices, which are designed for use with conventional valve bags. If the film bag is provided flat in the unfilled state, the displacement of contained air must not be taken into account during filling. In addition, the filling at a bag corner or a short longitudinal connection between the converging side folds is particularly expedient because the contents can be evenly distributed in the foil bag from there, and the foil bag can be completely filled without a substantial cavity.

At the same time, the foil bag according to the invention distinguishes itself from the various designs of valve sacks known for a long time by a better dimensional accuracy and a higher-quality appearance. The six sections formed by the two front walls and the four side folds are connected by heat sealing seams along the sides of a cuboid (based on the filled foil bag), these heat sealing seams on the one hand give the desired structure and on the other hand contribute significantly to a particularly high stability. One of the six surfaces, preferably a gusset is then provided as a floor stand. In the case of a filled foil bag, a flat standing surface is thus provided, without - unlike a crossbase - partially overlapping a plurality of foil layers and thereby also forming steps. With a filled foil bag fall in terms of stability and the first formed at the gussets center fold lines not significant.

The film bag according to the invention is characterized by a very good stability both in the full and in the partially emptied state, which is made possible by the cuboid shape tight packing and good stackability.

Since the front walls and the side folds are interconnected by heat sealing seams and the gussets are inserted in a flat foil bag between the front walls, heat sealing seams are usually produced in the production of the foil bag, where the two at the first corner converging in itself heat-sealable gussets remain unconnected. So there are special measures necessary to connect in the production of the heat sealing seams at the first corner of the converging side gussets. For example, it is conceivable to locally provide a release varnish at the position of the heat-sealing seams to be formed, in which case a closure outside the release varnish can also take place through the filling opening.

According to a preferred embodiment of the invention, however, it is provided that at the filling opening an additional release film between the converging there, unconnected gussets is arranged. In particular, the release film is arranged in two layers to form a filling valve.

Within the scope of such an embodiment, there are several advantages. First, the use of a preferably two-ply separating film leads to a reinforcement of the filling opening. A filling tube or funnel can then be inserted into the filling valve formed by the separating film, whereby a secure hold can be achieved by the reinforcement. In particular, a tearing or widening can be avoided by a correspondingly rigid and tensile design of the release film in the region of the filling opening when a filling hose or funnel is introduced.

In addition, the reinforced by the release film filling opening can also be easily handled and spread in particular for the introduction of the filling hose or funnel. The release film may be suitably adjusted to the filling process in terms of rigidity and lubricity.

In addition, a particularly advantageous valve function can be achieved. In particular, when the release film is sealed directly to the boundary of the filling opening and starting from an internal space of the film bag is movable, an automatic valve function is achieved. The filling material arranged inside the foil bag automatically presses the flexible valve and can thus not leave the foil bag. Especially with granular or powdery products, a closure can be sufficient alone by a filling valve designed in this way, so that no further closure is needed.

With regard to the valve function described, it is advantageous if the film bag is arranged so that the first corner is located on a bottom of the bag and the filling valve is arranged parallel to the side fold, which forms a floor stand. It then results in the advantage that the filling valve is less conspicuous.

According to the invention, the front walls and the side folds on the inside of the bag have the sealing layer and on the outside of the bag the outside layer. In principle, the front walls and all gussets can be formed from blanks of a uniform material of a bag film. Thus, according to a preferred embodiment of the invention, it is provided that the sealing layer of the front walls and the lateral folds is formed of polyolefin, including polyolefin copolymer, with polyethylene (PE) and also polypropylene (PP) being particularly preferred.

In addition to classic polyolefins, it is also possible to use polyolefins or non-polyolefin-based thermoplastic for the sealing layer, which are bio-based and / or biodegradable.

The thickness of the sealing layer is typically between 20 .mu.m and 150 .mu.m, in particular between 50 .mu.m and 120 .mu.m, wherein the selection of a suitable thickness may also depend on the material actually selected. A common value for a polyethylene (PE) sealing layer is 100 μm.

As the outer layer, a polyethylene terephthalate (PET) is particularly preferred, wherein the outer layer may have, for example, a thickness between 5 .mu.m and 60 .mu.m. A typical thickness of polyethylene terephthalate as the outer layer is 12 μm. Other materials suitable for the outer layer are in particular biaxially oriented PP (BOPP), oriented polyamide (OPA), cellulosic polymer, oriented polylactide (OPLA), with a suitable thickness to be selected depending on the material.

The foil for forming the front walls and the side folds is thus at least two-layered, it also being possible for further polymer layers, metallizations or the like to be provided. If the corresponding film is laminated according to a preferred embodiment of the invention, an internal printing can be provided in a contra-pressure, that the expression is then visible through the outer layer and optimally protected.

The layer structure described ensures that in the case of heat sealing at a suitable sealing temperature, only the inner sealing layer is melted and bonded to the adjacent film layer, while those on the side gussets, for example, are superimposed lying outer layers of the layers are not interconnected.

Also in the formation of a filling valve, the release film is preferably multi-layered and has at least one sealing layer, which, however, lies outside in the two-layer arrangement. On the inside, however, a separating layer is provided so that it rests on itself in the two-layer arrangement. The term release layer emphasizes that, in contrast to the outer sealing layer of the release film, it is not melted in the case of a sealing operation carried out in a corresponding manner. Against this background, the same materials are used, which are also intended for the formation of the front walls and gussets.

The release film is expediently arranged at the first corner in such a way that one layer of the release film rests flat against an associated side fold which, as described above, preferably forms a bottom of the foil bag.

The two layers of the release film may be bonded to the outer sealant layer in the heat seal seams with which one of the side folds converging at the first corner is bonded to the front walls, the layers of the release film terminating within a width of the respective heat seal seam. By means of the described measures it is achieved that the filling valve is securely fastened and circumferentially closed, wherein to ensure the integrity of the bag, the corresponding heat-sealing seams also extend laterally of the separating film in order to achieve a uniform, continuous sealing and connection.

In addition to this preferred embodiment, variants are also possible. The two layers of the release film can be folded from a strip, in which case the free ends of the strip are folded over so that there the sealing layer is inside and thus a peripheral closure can be done by a sealed seam. Additionally or alternatively, it is also possible to provide adhesive, in particular hot-melt adhesive, in order to fasten and / or close the separating film.

According to another aspect of the present invention, it is provided that the side folds converging at the first corner have a projection there over the associated side edges of the front walls. As is also known from generic foil bags, a straight line is usually guided by the lateral folds that run out at the corners, while the end of the other side fold is folded in a triangular shape in such a way that the central fold line of the corresponding side fold extends at right angles to the outside.

By the projection of the gussets at the first corner can also be achieved that the edge of the filling opening projecting laterally at the unfilled foil bag and can be handled easily. The filling opening, which is particularly preferably equipped with a filling valve, can thus be gripped and opened particularly easily.

If a completely airtight closure of the film bag is not necessary and in particular in the case of granular or powdery filling material, the valve function of the filling valve is utilized, a certain ventilation can also be ensured by the filling valve. For example, it may be necessary to allow pressure equalization in the event of temperature fluctuations, with it being possible for even chemical products in particular also to have a certain evolution of gas. Without restriction, however, it is also possible to provide at least one reclosure and / or one venting arrangement separately from the filling opening. Corresponding embodiments known from the prior art can also be realized at the appropriate location in the film bag according to the invention.

The film bag is particularly suitable for granular and powdery products such as construction products, cat litter, pelleted and powdered chemicals, detergents, food, pet food or the like. Furthermore, it is also possible to take up liquids of all kinds, but then usually a tight closure of the filling opening after a filling operation is necessary.

• - wobei eine Unterbahn aus Folie in einer Produktionsrichtung zugeführt wird, um daraus nachfolgend eine erste Frontwand sowie eine erste Seitenfalte und eine diese gegenüberliegende zweite Seitenfalte zu bilden,
• - wobei zur nachfolgenden Ausbildung einer dritten und vierten Seitenfalte quer zur Produktionsrichtung Folienstreifen, deren Randabschnitte auf einen Mittelabschnitt umgelegt sind und welche in einem Abstand zu den in Produktionsrichtung verlaufenden Längsrändern der Unterbahn enden, auf die Unterbahn aufgelegt werden,
• - wobei eine Oberbahn mit einer gegenüber der Unterbahn geringeren Breite zugeführt und auf die Unterbahn sowie die Folienstreifen aufgelegt wird,
• - wobei die Folienstreifen an dem Mittelabschnitt mit der Unterbahn und an den beiden Randabschnitten mit der Oberbahn insbesondere durch quer zur Produktionsrichtung verlaufende Heißsiegelnähte verbunden werden,
• - wobei ein Längsrand der Oberbahn mit den daran befestigten Randabschnitten derart zurückgefaltet wird, dass die Knicklinie zwischen den Randabschnitten und dem Mittelabschnitt abgewinkelt und dadurch an einer Oberseite von jedem Folienstreifen zwei dreieckige Zwickel gebildet werden,
• - wobei die Unterbahn mit dem entsprechenden Randbereich derart zurückgefaltet wird, dass die beiden Zwickel sowie der umgefaltete Rand der Oberbahn abgedeckt werden,
• - wobei aus dem umgefalteten Teil der Unterbahn eine erste Seitenfalte eines Beutelstranges derart durch Heißsiegeln und weiteres Falten gebildet wird, dass die erste Seitenfalte zur Ausbildung einer Befüllöffnung mit einem der Zwickel nicht verbunden ist.

The invention also relates to a method for forming filled or unfilled foil bags, each having two opposite rectangular front walls, four arranged between the front walls and the front walls connecting gussets and a filling,

• wherein a sub-web of film is fed in a direction of production in order subsequently to form a first front wall and a first side fold and a second side fold opposed thereto,
• - wherein for the subsequent formation of a third and fourth gusset transversely to the production direction foil strips, the edge portions are folded over to a central portion and which terminate at a distance to the direction of production extending longitudinal edges of the lower web, are placed on the lower web,
• - In which a top web is supplied with a relation to the lower web smaller width and on the sub-railway as well as the film strips are laid up,
• - wherein the film strips are connected at the central portion with the lower web and at the two edge portions with the upper web, in particular by running transversely to the direction of production heat sealing seams,
• - wherein a longitudinal edge of the top sheet is folded back with the attached edge portions such that the crease line angled between the edge portions and the central portion and thereby formed on an upper side of each film strip two triangular gussets,
• - wherein the lower web is folded back with the corresponding edge region such that the two gussets and the folded edge of the upper web are covered,
• - Where from the folded part of the lower web, a first gusset of a bag string is formed by heat sealing and further folding, that the first gusset is not connected to form a filling opening with one of the gusset.

By folding and heat sealing, a second side fold is formed, also opposite the first side fold of the bag line, wherein the first side fold and the second side fold can also be formed simultaneously with essentially the same measures. In the second gusset but then the corresponding portion of the lower web is connected to both gussets.

By cutting the bag string between the edge portions of the film strip individual unfilled foil bags are formed which are unlocked in the filling opening, while the other transitions between the front walls and the side folds of the foil bag on the one hand and between the side folds on the other hand are closed by heat sealing seams.

With the method according to the invention, in particular, the film bag previously described in detail can be formed, which is why reference is made to the further embodiment of the method on the characteristics of the film bag itself.

According to one embodiment of the invention, a preferably self-folded release film section is placed on one of the gussets on each film strip to subsequently avoid a connection during the production of heat sealing seams and thus to form the ventilation opening. In addition to the preferred arrangement of a release film are basically other measures such as the local arrangement of a release coating or the like conceivable.

As already described in connection with the foil bag itself, the filling opening can be formed with a projection with respect to an associated side of the bag.

In a conventional cutting operation of the flat-lying bag string, however, such a configuration initially also leads to a step in the front walls itself remaining on the corresponding side of the front walls. By forming such a step, the appearance may be impaired, and therefore, the projecting portion of the front wall can also be removed.

In particular, it is provided according to a preferred embodiment of the invention that the lower web, the upper web and the film strips are provided there with a recess, where subsequently the filling opening is formed with a projection. In the film strip, the recess is expediently formed on the middle section and one of the two edge sections.

The cutting of the bag string to form individual foil bags as well as the production of the recesses can take place in different ways, wherein in an automated production process, punching in particular comes into consideration. In addition, however, it is also possible, for example, to cut with a laser or a knife.

When cutting the bag string, the cut takes place in the region of the individual film strips, wherein the side folds of the successive film bags are formed from a film strip. In order to provide clean edges and to form the filling opening with a supernatant, preferably a cutting strip is cut out during the cutting of the bag string between the successive foil bags (outside a possibly provided step), for example a width between 10 mm and 40 mm, in particular 30 mm can.

After cutting the bag string, the film bag can be filled through the filling opening and then assume a substantially cuboid shape. Optionally, it is also possible to close the filling opening after filling. In a preferred embodiment with a self-folded release film to form a film valve, the overlapping layers lying on top of each other can be provided with a first subsequently activatable adhesive or a partial coating of hot-melt adhesive, this is at a location where no sealing seams were previously formed.

Furthermore, it is also possible to introduce an adhesive directly into the filling opening only after filling, wherein it can be without limitation a physically and / or chemically curing plastic including hotmelt.

In addition, other measures come into consideration to close the filling opening. In a particularly simple embodiment, an adhesive strip can be placed from the outside over the filling opening. Depending on the material can be folded over at a supernatant of the filling of this supernatant. Furthermore, it is also possible to seal the separating layer, which in itself is only badly sealable, with itself by suitable measures, for which purpose a correspondingly high local energy input can be achieved, for example by ultrasonic welding. Furthermore, it is also possible that the corresponding sections of the gussets draining out at the first corner extend beyond the separating film, so that then there is a closure by heat sealing outside the separating film at an outermost edge of the filling opening.

• 1 einen Folienbeutel, der mit einer Befüllöffnung an eine Befülleinrichtung angeschlossen ist,
• 2 den in 1 dargestellten Folienbeutel im befüllten Zustand,
• 3 den Folienbeutel gemäß der 1 und 2 in einem unbefüllten, flachgelegten Zustand in einer Draufsicht,
• 4 Schnitt entlang der Linie A-A der 2.,
• 5A bis 5I Verfahrensschritte zur Herstellung des Folienbeutels,
• 6A bis 6C Schritte bei einem hinsichtlich der 5A bis 5I modifizierten Verfahrensführung.

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

• 1 a foil bag, which is connected with a filling opening to a filling device,
• 2 the in 1 illustrated foil bag in the filled state,
• 3 the foil bag according to the 1 and 2 in an unfilled, flattened state in a plan view,
• 4 Cut along the line AA the 2 .,
• 5A to 5I Process steps for the production of the film bag,
• 6A to 6C Steps in one regarding the 5A to 5I modified process management.

The 1 to 3 show different views and different states of a foil bag. While the foil bag in the 3 laid flat, shows the 1 the foil bag during filling while the 2 represents the filled foil bag.

From the 1 to 3 It can be seen that the film bag in the filled state a cuboid shape with two opposite rectangular front walls 1 and four between the front walls 1 arranged and the front walls 1 connecting gussets 2a . 2 B . 2c . 2d , Furthermore, there is a filling opening 3 provided, which at a first corner of the front walls 1 formed by the fact that there the converging gussets 2a . 2c are not interconnected, while at the other corners of the front walls 1 the gussets that converge there 2a . 2 B . 2c . 2d each by a heat seal seam 4 are connected.

Furthermore, also the front walls 1 with the gussets arranged between them 2a . 2 B . 2c . 2d about more heat-sealed seams 4 ' connected. To make the film bag by heat sealing, have the front walls 1 as well as the gussets 2a . 2 B . 2c . 2d each on a bag inside a sealant layer 5 and on a bag outside an outer layer 6 on, with the outer layer 6 a higher softening temperature or sealing temperature than the sealing layer 5 has (see. 4 ).

According to the 1 is a hopper 7 in the filling opening 3 used. This results in the advantage that the initially flat foil bag can be filled very well, with the arrangement of the filling opening 3 in the corner, the entire available filling volume can be exploited.

The 2 shows starting from the filled foil bag, wherein the filling opening 3 is no longer spread and is located on a bottom of the foil bag. The in the 1 overhead gusset 2a now forms a floor.

At the formation of the film bag at the first corner between the converging side folds 2a . 2c to avoid a closure and the filling opening 3 initially open, there is a self-folded additional release film 8th provided, which forms a film valve by their design and the type of integration. A break line of the release film 8th and the opposite ends are each in heat seal seams 4 ' integrated with those in 2 the bottom of the film bag forming the first gusset 2a on the two front walls 1 is attached. The extent of the release film 8th is in the 2 also indicated by a dashed line, after which the release film 8th within the associated heat seal seams 4 ' ends.

This ensures on the one hand that the bag is laterally of the release film 8th securely closed and on the other hand, the release film 8th firmly and wrapped around the perimeter is included.

Further details on the design and function of the release film as a film valve are from the 4 which shows a section along the Line AA the 2 shows. Accordingly, the release film has 8th a seal layer external to the two-ply fold 5 ' as well as an internal, that is due to the two-layer arrangement on itself resting release layer 9 on. The release film 8th is by heat sealing seams 4 ' with the two adjacent gussets 2a . 2c connected, these heat sealing seams 4 ' similar to the other heat-sealed seams 4 is formed, with which the gussets 2a . 2 B . 2c . 2d connected to the other corners of the front walls. Because the separation layer 9 however, are formed of a non-heat sealable or heat sealable material only at a higher temperature is used in the production of the corresponding heat sealing seams 4 ' the area with the release film 8th kept open.

In the interior of the film bag inside the release film is located 8th largely free. This results in a valve function. When the filling hole 3 with the used release film 8th spread, the bag can be as in 1 be easily filled. If, however, that of the release film 8th formed filling valve is flattened by the superimposed layers of the release film 8th an escape of the contents avoided. Particularly in the case of granular but also powdery products, a closure can be achieved solely by that of the release film 8th be formed filling valve sufficient.

The 5A to 5I show steps in the production of the foil bag, wherein first a continuous bag string 10 is formed from which then individual foil bags are cut off.

According to the 5A first becomes a subway 11 fed from film in a direction of production P, in order subsequently from the individual foil bags one of the front walls 1 as well as the first gusset 2a and the opposite second gusset this 2 B to build. Also, the formed as an intermediate bag string 10 has gussets, with simplicity not between the gussets 2a . 2 B . 2c . 2d the individual foil bag and the bag string 10 a distinction is made.

For the subsequent formation of the third and fourth gusset 2c . 2d by a later described cutting the bag string 10 become transverse to the production direction P in an equidistant distance foil strips 12 supplied, the edge portions 13 on a middle section 14 are folded, with the film strips 12 in the middle of the subway 11 be applied and where the film strips 12 at a distance to the edges of the sub-web 11 end up.

The foil strips 12 be after laying on the sub-web 11 expediently at least prefixed. Then there is a top track 15 with one opposite the lower course 11 fed to the lower width and on the lower web 11 as well as the foil strips 12 hung up. The subway 11 , the upper railway 15 and the foil strips 12 each have the sealing layer 5 and the outer layer 6 on, which are already described previously in connection with the foil bag. The seal layers 5 are arranged so that with a schematically indicated sealing tool 16 the foil strips 12 through transverse to the production direction heat sealing seams 4 ' at the middle section 14 with the subway 11 and at the two edge sections 13 with the upper track 15 get connected. Specifically, the heat seal seams 4 ' directly to the free end of the edge sections 13 educated.

Then the two longitudinal edges of the top sheet 15 folded back, wherein the attachment by means of the heat sealing seams 4 ' also the attached edge sections 13 be folded back so that the crease line between the edge portions 13 and the middle section 14 is angled.

For an edge of the upper runway 15 this is in the detail in the 5B shown. By folding over the edge of the upper runway 15 are at each end of the film strip 12 triangular gussets on top 17a . 17b formed, wherein subsequently according to the 5C on one of the gussets 17a the self-folded release liner 8th is hung up.

According to the 5D becomes the subway 11 folded back in the corresponding edge region such that the two gussets 17a . 17b the release film 8th as well as the folded edge of the upper runway 15 be covered.

According to the 5E then takes place across the production direction P there a seal, whereupon the folded edge of the sub-web 11 is fixed to the underlying elements and subsequently only over half his length (and together with the upper web 15 ) can be folded back ( 5F) , which ultimately makes the first gusset 2a (first of the bag string 10 ) is formed.

Then, according to the 5G more heat-sealed seams 4 ' along the production direction P educated. On the opposite side may be the second gusset 2 B (of the bag string 10 ) are formed in principle in the same way, where there is no release film 8th is applied and thus in the production of the heat-sealing seams - as well as the second gusset 17b - A tight seal takes place.

According to the 5H be by cutting the bag string 10 between the edge sections 13 the foil strip 12 individually unfilled foil bag formed, which in the region of the filling 3 through the separating film forming a filling valve 8th are unlocked while the further transitions between the front walls 1 and the gussets 2a . 2 B . 2c . 2d the foil bag on the one hand and between the gussets 2a . 2 B . 2c . 2d on the other hand by the heat sealing seams 4 . 4 ' are closed.

When cutting the bag string 10 becomes a blend strip 18 cut out, outside the area of the release film 8th for example, may have a width of 30 mm. On the release film 8th is a level on the other hand 19 of the blend strip 18 provided so that the filling opening 3 laterally across the rectangular basic shape of the front walls 1 can protrude. According to the 5I This results in a certain optical restriction, because accordingly also the front walls 1 have no exact rectangular shape, but also the shape of the step 19 replicate.

When the filling opening 3 should not protrude laterally, is the formation of such a stage 19 Of course not necessary. For practical reasons, however, a lateral projection of the filling opening 3 in many cases preferred in order to facilitate the simplest possible handling, in particular in connection with an automated filling device.

To be on the front walls 1 to avoid a step shape is according to the 6A to 6C a variant of the method shown, wherein the process steps not described in detail are carried out exactly as explained above.

According to the 6A show the foil strips 12 there a recess 20 on where later the release film 8th is arranged. The recess 20 can be formed for example by punching and is in accordance with the 6A at the middle section 14 as well as one of the edge sections 13 ,

Also the subway 11 as well as the upper railway 15 be with recesses 20 provided, which then in an arrangement according to the 5D be placed on top of each other in cover. In an otherwise identical procedure with respect to the subsequent steps is thus according to the 6B (corresponding 5F) that reaches through the recess 20 the front walls 1 in the finished foil bag also at the filling opening 3 run exactly straight (see also 6C) ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• GB 2317159 A [0009]
• DE 6605249 U [0012]
• DE 6945778 [0013]
• EP 1935797 B1 [0014]
• WO 2016/189541 A1 [0014]
• WO 2017/051431 A1 [0014]

Claims (17)

Film bag with two opposing rectangular front walls (1), with four arranged between the front walls (1) and the front walls connecting gussets (2a, 2b, 2c, 2d) and with a filling opening (3), wherein the front walls (1) and the Side folds (2a, 2b, 2c, 2d) each have on a bag inside a sealing layer (5) and on a bag outside an outer layer (6), wherein the outer layer (6) has a higher melting temperature than the sealing layer (5) and wherein the front walls (1) are connected to the side folds (2a, 2b, 2c, 2d) arranged between them by means of heat-sealing seams (4 '), characterized in that the filling opening (3) is formed at a first corner of the front walls (1) in that the side folds (2a, 2c) converging there are unconnected, while the side folds (2a, 2b, 2c, 2d) converging there are connected to the remaining corners of the front walls (1) by a heat-sealing seam (4). Foil bag after Claim 1 , characterized in that at the filling opening (3) an additional separating film (8) between the converging there, unconnected gussets (2a, 2c) is arranged. Foil bag after Claim 2 , characterized in that the release film (8) is arranged in two layers and forms a filling valve. Foil bag after Claim 3 , characterized in that the two-ply separating film (8) has an outer sealing layer (5 ') and an inner separating layer (9). Foil bag after Claim 4 , characterized in that a layer of the release film (8) lies flat against an associated gusset (2a). Foil bag after Claim 4 or 5 , characterized in that the two layers of the release film (8) with the outer sealing layer (5 ') in the heat sealing seams (4') are incorporated, with which one of the converging at the first corner gussets (2a, 2c) with the front walls ( 1), the layers of the release film (8) terminating within a width of the respective heat seal seams (4 '). Foil bag after one of Claims 1 to 6 , characterized in that the converging at the first corner gussets (2a, 2c) there have a projection with respect to the associated side edges of the front walls (1). Foil bag after one of Claims 1 to 7 , characterized in that separate from the filling opening (3) at least one reclosure and / or a venting arrangement is provided. Foil bag after one of Claims 1 to 8th characterized in that the sealing layer (5) of the front walls (1) and side gussets (2a, 2b, 2c, 2d) is formed of polyolefin including polyolefin copolymer having a thickness of between 20 μm and 150 μm, and the outer layer is the main component a material selected from the group consisting of polyethylene terephthalate, biaxially oriented polypropylene, oriented polyamide, oriented polylactide or mixtures of said polymers. A method for forming film bags, each having two opposing rectangular front walls (1), four arranged between the front walls and the front walls connecting gussets (2a, 2b, 2c, 2d) and a filling opening (3), wherein - a lower web (11) Film is fed in a production direction (P) in order subsequently to form a first front wall (1) and a first gusset (2a) and a second gusset (2b) opposite thereto, - for the subsequent formation of a third and fourth gusset (2c, 2d) transversely to the production direction (P) film strips (12), the edge portions (13) are folded over a central portion (14) and which at a distance to the production direction (P) extending longitudinal edges of the sub-webs (11) end, on the lower web (11) are placed, - fed to a lower web (15) with respect to the lower web (11) smaller width and the lower web (11) and the film strips (12) is applied, - the film strips (12) at the central portion (14) with the lower web (11) and at the two edge portions (13) are connected to the upper web (15), - a longitudinal edge of the upper web (15) with folded back to the attached edge portions (13) such that the crease lines between the edge portions (13) and the central portion (14) angled and thereby at one top of each film strip (12) two triangular gussets (17a, 17b) are formed, the lower web (11) is folded back with the corresponding edge region such that the two gussets (17a, 17b) and the folded-over edge of the upper web are covered, - subsequently from the folded part of the lower web (11) a first gusset (2a) of a bag string (10) is formed by heat sealing and further folding such that the first gusset (2a) is not connected to one of the gussets (17a) to form a filling opening, - by folding and heat sealing opposite the first gusset of the bag string (10) a second gusset (2b) is formed, by cutting the bag string (10) between the edge portions (13) of the film strips (12) individual unfilled foil bags are formed. Method according to Claim 10 , wherein the individual unfilled foil pouches are formed by cutting the pouch string (10) such that the foil pouches in the region of the filling opening (3) are unlocked, while the further transitions between the front walls (1) and the side folds (2a, 2b, 2c, 2d) of the film bag on the one hand and between the side folds (2a, 2b, 2c, 2d) with each other by heat sealing seams (4, 4 ') are closed. Method according to Claim 10 or 11 in that on each foil strip (12) a portion of a release film is placed on one of the gussets (17a), in order subsequently to avoid connection during the production of heat-sealing sutures and thus to form the filling opening (3). Method according to one of Claims 10 to 12 , wherein the filling opening (3) is formed with a projection with respect to an associated bag side. Method according to Claim 13 , wherein the lower web (11), the upper web (15) and the film strips (12) are each provided there with a recess (20), where subsequently the filling opening (3) is formed. Method according to one of Claims 10 to 14 in which a blending strip (18) is cut out during the cutting of the bag string (10) between successive foil bags. Method according to one of Claims 10 to 15 , wherein after the cutting of the bag string (10), the foil bags are filled through the filling opening (3). Method according to Claim 16 , wherein the filling opening (3) is closed after filling.

Images