EP1226929B1 - Process and machine for production of zipper gusset bags - Google Patents

Abstract

The bag, designed to be made automatically from a continuous strip of thermoplastic-based film material, is produced by making cut-outs in the film layer in zones corresponding to the ends of lengthwise side pleats, fitting transverse closure strips (70) in alignment with the cutouts, forming the pleats (40, 42), and bringing the edges (14, 16) of the film sheet together to make a lengthwise central weld seam.

Description

The present invention relates to the field of packaging bags.

More specifically, the present invention relates to the field of sachets packaging having side gussets.

Many processes for producing side bellows bags have already been proposed.

By way of non-limiting examples, reference may be made to documents FR-A-2758761, FR-A-2686063, US-A-5938339, US-A-6068585, DE-A-3824753 and JP-A-07214702.

JP-A-07100972 discloses a method of manufacture packing bags which consists in driving a sheet intended for forming a packaging bag, in a longitudinal direction which coincides with its elongation direction, sequentially forming pairs of cuts respectively in two areas of the sheet of packaging bag for forming side gussets longitudinally, form longitudinal lateral gussets on the leaf, and bring the longitudinal edges of the sheet closer together and fix its edges longitudinal sides of the sheet to close the bag. subsequently, in a separate step, closure means based on complementary profiles are placed sequentially and transversely on the sheet, opposite the area of the sheet between two associated cuts, and are fixed on the sheet.

The present invention now aims to propose new means for manufacturing pouches with side gussets.

This object is achieved in the context of the present invention by means of a method as defined in appended claim 1, which is delimited in the form of a preamble and a part characterizing with respect to JP-A-07 100 972

According to another advantageous characteristic of the present invention, means of closure based on complementary profiles are carried by a band folded on itself in U to form two generally parallel support wings between them, oriented transversely to the longitudinal direction of the bag and fixed respectively on the inner face of two main panels of the bag formed by said sheet.

According to another advantageous characteristic of the present invention, closure means based on complementary profiles comprise a slider control.

The present invention also relates to a machine for the implementation of of the aforementioned process as defined in a independent claim attached.

• les figures 1 à 4 représentent schématiquement 4 étapes principales successives du procédé conforme à la présente invention,
• les figures 5 et 6 illustrent schématiquement les moyens destinés à la réalisation des soufflets latéraux,
• la figure 7 illustre schématiquement un ensemble de sachets en chapelet conforme à la présente invention, et
• les figures 8 et 9 représentent schématiquement, selon des vues en coupe transversale, deux variantes de sachets conformes à la présente invention comportant des moyens de fermeture équipés d'un curseur.

Other features, objects and advantages of the present invention will appear on reading the detailed description which follows and with reference to the appended drawings, given by way of non-limiting examples, and in which:

• FIGS. 1 to 4 schematically represent 4 successive main steps of the method according to the present invention,
• FIGS. 5 and 6 schematically illustrate the means intended for producing the lateral gussets,
• FIG. 7 schematically illustrates a set of rosary bags according to the present invention, and
• Figures 8 and 9 show schematically, in cross-sectional views, two variants of bags according to the present invention having closure means equipped with a slider.

FIG. 1 appended hereto shows a sheet 10 whose direction of elongation is referenced 12 and the longitudinal edges which are parallel thereto, are referenced 14 and 16.

The sheet 10 is driven by displacement, by any appropriate means, typically from a reserve roll, according to its elongation direction 12.

As shown in FIG. 1, pairs of cutouts 20, 22, are performed sequentially in the sheet 10, in two zones 30, 32 of the sheet 10 intended to subsequently form lateral longitudinal bellows 40, 42.

Such cuts 20, 22 can be made using a punch classics shown as 21, 23 in Figure 1. The scrolling of the film 10 in the direction 12 can be interrupted during the movement of punch 21, 23.

In Figure 1, there is referenced 18 a generatrix transverse direction of elongation 12 which coincides with the top of a bag.

As can be seen in FIG. 1, the cutouts 20, 22 open onto this generator 18.

The longitudinal pitch (i.e. in direction 12) separating two pairs adjacent cuts 20, 22 is equal to the pitch of the bags.

The geometry of the cuts 20, 22 may be subject to various variants. Advantageously, the cutouts 20, 22 are rectangular, their sides being respectively parallel to the direction of longitudinal elongation 12 and to the transverse direction 18.

Preferably, the transverse dimension d1 of cutouts 20, 22 is equal to the cumulative width of the flaps 50,52 defining the concave internal dihedral side gussets 40, 42.

For a final longitudinal closure seam 60 of the bag located at half-width thereof, (as illustrated in Figure 4) the two cutouts 20, 22 are symmetrical with respect to the middle of the sheet. On the other hand, if the weld longitudinal closure 60 must be offset relative to the middle of the bag, the cutouts 20, 22 are shifted accordingly, the distance d2 separating the two cutouts being equal to the width of the main panel composing the bag.

The sum d5 + d6 of the widths of the panels formed on the outside of the cuts 20, 22 is equal to the width d2 of the panel formed between the cuts 20, 22 plus twice the width d4 required to fix the longitudinal edges 14, 16 between them.

As can be seen in FIGS. 2 and 3, two lateral bellows 40, 42 are then formed in the sheet 10 and closure means 70 are placed sequentially and transversely on the sheet 10 opposite the zone located between two cuts 20, 22.

The means for conveying and positioning the closing means 70 on the film, may be formed of any means known to those skilled in the art, by examples those described in the aforementioned prior documents.

According to the illustration given in the figures, the lateral bellows 20, 22 are roughed before the closure means 70 are placed on the sheet 10.

However, the opposite arrangement can be retained, ie variant the closure means can be placed on the sheet 10 before the side gussets 40, 42 are sketched or made.

In the context of the present invention, the closure means 70 are formed preferably of complementary profiles 72, 74 carried by wings respective supports 77, 78, for example in the form of a strip 76 folded on itself in U. Thus, the band 76 forms two support wings 77, 78 globally parallel to each other transversely oriented to the longitudinal direction 12 of the bag.

The complementary profiles 72, 74 may be subject to various variants. It may be for example complementary hook structures or still respectively of a male element in the form of an arrow and an element female throat with converging edges.

The U-shaped closure band 76 may have its concavity turned towards inside or towards the outside of the bag.

Moreover, the closure band 76 can have its concavity turned towards upstream or downstream with respect to the direction of movement of the sheet 10.

Once positioned on the sheet 10, the lower support wing 78 of the means of closure is fixed, preferably by welding (where appropriate by sticking, or any other appropriate means) on the underlying bottom panel of the sheet 10.

If necessary, to facilitate the fixing of the closure means 70 by welding, the two wings 77, 78 may have different widths (in this hypothesis the lower wing 78 is the widest).

A reference numeral 79 in FIG. transverse weld, intended to ensure the attachment of the lower wing 78 to the film 10.

The lateral gussets 40, 42 are formed using any means with, for example, parallel blades 80, 82, 84, 86 extending into the longitudinal direction 12 and whose longitudinal edges 81, 83, 85 and 87 alternatively external or internal are shifted by an amplitude equal to desired depth of the bellows, as shown in FIG.

More precisely still according to the representation illustrated in the figures appended, the lateral bellows are made in two stages: at first (FIG. 2) two parallel longitudinal folds 44, 46 are made at the level of each bellows 40, 42, then shaped in Z, then in a second step (FIG. 4) a last longitudinal fold 48 is made at each bellows 40, 42 for each complete these.

The third fold 48 can be made for example with the aid of a third blade 88, 90, as illustrated in FIG. 6, whose external longitudinal edge 89, 91 is superimposed on the outer edge 81, 85 of the lower blade 80, 84.

Typically the width d3 of each elementary panel formed between a longitudinal edge 14, 16 and an inner fold 46 is equal to the sum of half of the width d2 of the lower panel formed between the two outer plies 44, the depth d1 / 2 of the bellows (distance between the folds 44 and 46) and the width d4 necessary for fix the longitudinal edges 14, 16 between them (this for a longitudinal weld median). In the case where the longitudinal weld is not median, the sum of the widths of the two elementary panels respectively formed between the edges 14, 16 and an inner fold 46 is equal to the sum of the width d2 of the lower panel formed between the two outer plies 44, the double d1 of the depth of the bellows and double the width d4 needed to secure the edges longitudinal 14, 16 between them.

It then remains to bring the two longitudinal edges 14, 16 of the sheet closer together 10 and to fix them by any appropriate means, preferably by welding, or even by gluing or other equivalent means and to fix the second support wing 77 of the closing means on the top panel of the sheet composing the bag.

The longitudinal edges 14, 16 can be brought together by any means appropriate, for example using known rollers or chutes.

FIG. 4 shows schematically in 61, 62 two welding jaws longitudinally welded 60 and a diagram has been made in 63 of transverse jaw likely to fix the second wing 77 means of closure 70.

The methods of transverse closure and filling of the sachets may be subject to various embodiments.

• l'ensemble tubulaire obtenu après mise en oeuvre des étapes précitées peut être conditionné en l'état, par exemple enroulé sur lui-même ou plié en zig-zag autour de plis transversaux, afin d'être exploité ultérieurement, par tronçonnage pour individualiser les sachets, remplir ceux-ci puis les fermer, par exemple à l'aide d'une soudure transversale au niveau du fond des sachets ;
• en variante, chaque élément formant un sachet peut être individualisé par tronçonnage transversal en vue d'un remplissage et d'une fermeture ultérieurs ;
• chaque élément de l'ensemble tubulaire précité correspondant à un sachet peut recevoir son contenu avant réalisation du dernier pli 48. Dans ce cas chaque sachet peut être fermé hermétiquement par réalisation d'un joint transversal, par exemple par soudure, et individualisé par tronçonnage transversal entre ce joint correspondant au fond d'un sachet et les moyens de fermeture correspondant au sommet d'un sachet adjacent ;
• en variante l'ensemble tubulaire précité peut être pourvu séquentiellement de découpes transversales 100 réalisées dans l'un de ses éléments de parois, comme schématisé sur la figure 7, pour constituer un chapelet de sachets en série. Ces découpes 100 sont réalisées sur la génératrice 18, entre le sommet d'un sachet et le fond du sachet adjacent. De telles découpes 100 peuvent être formées dans le film 10 simultanément aux découpes 20, 22. La présence de telles découpes facilitent le remplissage ultérieur en cascade des sachets. Une fois les sachets remplis, ceux-ci peuvent être obturés en scellant les découpes 100 par soudure.

As non-limiting examples:

• the tubular assembly obtained after implementation of the above steps may be packaged in the state, for example wound on itself or folded zig-zag around transverse folds, to be operated later, by cutting to individualize the sachets, fill them and then close them, for example using a transverse weld at the bottom of the bags;
• alternatively, each bag-forming member may be individualized by transverse cutting for subsequent filling and closing;
• each element of the above-mentioned tubular assembly corresponding to a sachet can receive its contents before the last fold 48 is made. In this case each sachet can be hermetically closed by making a transverse seal, for example by welding, and individualized by transverse cutting. between this seal corresponding to the bottom of a bag and the closing means corresponding to the top of an adjacent bag;
• alternatively, the above-mentioned tubular assembly may be provided sequentially with transverse cuts 100 made in one of its wall elements, as shown diagrammatically in FIG. 7, to constitute a series of sachets in series. These cuts 100 are made on the generator 18, between the top of a bag and the bottom of the adjacent bag. Such cuts 100 may be formed in the film 10 simultaneously with the cuts 20, 22. The presence of such cutouts facilitate the subsequent cascade filling of the bags. Once the bags are filled, they can be closed by sealing the cuts 100 by welding.

Of course, the present invention is not limited to the modes of particular embodiments which have just been described, but extends to all variants consistent with his spirit.

As mentioned above and as illustrated in FIG. closure means 70 may be equipped with a control slider 110. such known control slider itself will not be described in detail. We simply recall that such a cursor 110 generally comprises a base 112 connected to two side flanks 113, 114 arranged on either side of a soleplate central 116 designed to be placed between the closure profiles complementary. The lateral flanks 113, 114 define in combination with the center sole two channels converging towards one end of the slider. The moving the cursor in one direction (convergent end of the downstream channels) close the closing profiles and close the bag. Moving the cursor 110 in the opposite direction separates the closing profiles 72, 74 thanks to the sole 116 and opens the bag.

FIG. 8 thus shows a U-shaped strip 76 with concavity directed outward and equipped with a slider 110.

FIG. 9 illustrates another variant of embodiment according to which the strip 76 is W, the closure profiles 72, 74 being placed between the faces the internal U-shaped element of this band 76, this U-shaped inner element having its concavity towards the outside.

It will be noted that in the context of the present invention the U-shaped support strip 76 forms a witness of first opening of sachet.

Indeed, it is necessary to break this band 76 to access the contents of the sachet.

Thus the rupture of the band 76 is the witness of the opening of the bag.

If necessary, the band 76 may have a line of weakness, for example example in the form of a line of pre-cut, to facilitate the opening of the bag.

In the context of the process according to the present invention, the sheet can be moved in one direction or the other in the longitudinal direction 12.

The means for cutting the film 10 and sealing or closing in the aforementioned transverse direction, can be integrated in the transverse jaw schematized under the reference 63 in FIG.

Furthermore, preferably, the closure assembly 70 is attached to the film 10 is ensured so that it ensures a seal between the means of closure 70 and the film 10 and therefore also guarantees thereby the tightness of the bag finally obtained. For this purpose preferably, the length of the closure band 70 is adapted so that the closure means 70 is adjacent, or if necessary, partially overlaps the contour of the cuts 20, 22. Moreover, preferably the fastening means of the closure strip 70 ensure a welding the ends thereof to the film 10.

The film 10 used in the context of the present invention may be any embodiment known to those skilled in the art.

It is preferably a film based on thermoplastic material, monofilament or multi-layer (s), mono- or multi-material (x). If necessary, it may be a paper support coated with a layer of thermoplastic material, or a layer of partially metallized thermoplastic material.

Claims (26)

1. Method of manufacturing packaging bags with side gussets comprising the steps which consist in:

   a) - driving a sheet (10) that is intended to form a packaging bag in a longitudinal direction (12) which coincides with its direction of elongation,

   b) - sequentially forming pairs of cutouts (20, 22) in two respective regions (30, 32) of the sheet of packaging bag which regions are intended to form longitudinal side gussets (40, 42), the cutouts (20, 22) opening onto a transverse generatrix (18) of the sheet which corresponds to the top of a respective bag,

   c) - sequentially and transversely placing closure means (70) based on complementary profiles on the sheet (10) facing the region thereof that lies between two associated cutouts (20, 22),

   d) - forming longitudinal side gussets (40, 42) on the sheet (10),

   e) - bringing the longitudinal edges (14, 16) of the sheet (10) together, fixing together its touching longitudinal edges (14, 16) of the sheet to close the bag, and fixing the closure means (70) based on complementary profiles, onto the sheet, characterized in that the abovementioned step c) is carried at before step e).
2. Method according to Claim 1, characterized in that the closure means based on complementary profiles (70) comprise an operating slider (110).
3. Method according to Claim 1 or 2, characterized in that the closure means (70) based on complementary profiles are borne by a strip (76) folded onto itself in the shape of a U to form two support flanges (77, 78) which are roughly parallel to one another, oriented transversely to the longitudinal direction (12) of the bag and fixed respectively to the inside of two main panels of the bag which are formed by said sheet.
4. Method according to Claim 3, characterized in that the U-shaped strip (76) has its concave side facing towards the outside of the bag.
5. Method according to either of Claims 1 and 2, characterized in that the strip (76) is in the shape of a W, the closure profiles (72, 74) are placed between the insides of the U-shaped internal element of this strip, this U-shaped internal element having its concave side facing towards the outside and the lateral branches of the strip (76) being fixed to the walls of the bag.
6. Method according to one of Claims 1 to 5, characterized in that the cutouts (20, 22) have a rectangular outline.
7. Method according to one of Claims 1 to 6, characterized in that the longitudinal spacing separating two adjacent pairs of cutouts (20, 22) is equal to the spacing of the bags.
8. Method according to one of Claims 1 to 7, characterized in that the transverse dimension (d1) of the cutouts (20, 22) is equal to the combined width of the flaps (50, 52) defining a concave internal dihedron of the side gussets (40, 42).
9. Method according to one of Claims 1 to 8, characterized in that the cutouts (20, 22) are symmetric with respect to the middle of the sheet.
10. Method according to one of Claims 1 to 9, characterized in that the distance (d2) separating the two cutouts (20, 22) is equal to the width of a main panel of which the bag is made.
11. Method according to one of Claims 1 to 10, characterized in that the side gussets (20, 22) are roughed out in the form of two longitudinal folds (44, 46) before the closure means (70) are deposited.
12. Method according to one of Claims 1 to 11, characterized in that a support flange (78) of the closure means (70), adjacent to the sheet (10), is fixed to the latter before the longitudinal edges (14, 16) of the sheet are brought together and fixed.
13. Method according to Claim 12, characterized in that the second support flange (77) of the closure means (70) is fixed to the sheet (10) after the longitudinal edges (14, 16) of the sheet have been brought together.
14. Method according to one of Claims 1 to 13, characterized in that the closure means (70) are fixed in such a way that this fixing seals the closure means (70) to the sheet (10).
15. Method according to one of Claims 1 to 14, characterized in that it further comprises the step consisting in packing the tubular entity obtained after the aforementioned steps have been carried out, by rolling or by concertina-folding about transverse folds, with a view to later use.
16. Method according to one of Claims 1 to 14, characterized in that it further comprises the step consisting in making each bag into an individual bag by cutting transversely with a view to later filling and closing.
17. Method according to one of Claims 1 to 14, characterized in that it further comprises the step consisting in placing contents on the sheet (10) before the longitudinal edges (14, 16) of the sheet are brought together and fixed, and that it further comprises a step consisting in sealing each bag around these contents.
18. Method according to one of Claims 1 to 14, characterized in that it further comprises the step consisting in sequentially making transverse cutouts (100) in the tubular entity obtained after the aforementioned steps have been performed, so as to form a string of bags in series, each comprising a cutout (100) allowing subsequent filling of the bags.
19. Machine for manufacturing packaging bags with side gussets (40, 42), comprising:

    means capable of driving a sheet (10) that is intended to form a packaging bag in a longitudinal direction (12) which coincides with its direction of elongation,

    means (21, 23) capable of sequentially forming pairs of cutouts (20, 22) in two respective regions of the sheet of packaging bag which regions are intended to form longitudinal side gussets (42), the cutouts opening onto a transverse generatrix (18) of the sheet corresponding to the top of a respective bag,

    means capable of sequentially and transversely placing closure means (70) based on complementary profiles on the sheet facing the region thereof that lies between two associated cutouts (20, 22),

    means (80, 82, 84, 86, 88, 90) capable of forming longitudinal side gussets (42) on the sheet, and

    means capable of bringing the longitudinal edges (14, 16) of the sheet together, fixing together its touching longitudinal edges (14, 16) of the sheet to close the bag, and fixing the closure means (70) based on complementary profiles, onto the sheet, characterized in that the means intended to place the closure means (70) are placed in front of the means capable of forming longitudinal side gussets (40).
20. Machine according to Claim 19, characterized in that the closure means based on complementary profiles (70) comprise an operating slider (110).
21. Machine according to Claim 19 or 20, characterized in that the closure means (70) based on complementary profiles are borne by a strip (76) folded onto itself in the shape of a U to form two support flanges (77, 78) which are roughly parallel to one another, oriented transversely to the longitudinal direction of the bag and fixed respectively to the inside of two main panels of the bag which are formed by said sheet.
22. Machine according to one of Claims 19 to 21, characterized in that the two support flanges (77, 78) of the closure means (70) have different widths.
23. Machine according to one of Claims 19 to 22, characterized in that the means capable of forming the side gussets (42) are formed of longitudinal blades (80, 82, 84, 86, 88, 90) which are offset in the transverse direction.
24. Machine according to one of Claims 19 to 23, characterized in that the sum (d5 + d6) of the widths of panels formed on the outside of the cutouts (20, 22) is equal to the width (d2) of the panel formed between the cutouts (20, 22) plus twice the width (d4) needed to fix the longitudinal edges (14, 16) together.
25. Machine according to one of Claims 19 to 24, characterized in that the width (d3) of each elementary panel formed between a longitudinal edge (14, 16) and an internal fold (46) is equal to the sum of half the width (d2) of a lower panel formed between two external folds (44), the depth (d1/2) of the gussets (40, 42) and the width (d4) needed to fix the longitudinal edges (14, 16) together.
26. Machine according to one of Claims 19 to 25, characterized in that the sum of the widths of the two elementary panels formed respectively between the longitudinal edges (14, 16) and an external fold (46) is equal to the sum of the width (d2) of the lower panel formed between the two external folds (44), twice (d1) the depth of the gussets and twice the width (d4) needed to fix the longitudinal edges (14, 16) together.

Images