EP0197875A1 - Flexible synthetic bag comprising a means for rigidification and stabilisation - Google Patents

Abstract

Bag comprising on its front face (5) a means of stiffening and stabilization such as buttress (6) or vertical rib (7). Application: packaging of liquids.

Description

The present invention relates to a flexible plastic bag of the type obtained from at least one strip of plastic film shaped so as to determine by soldering a bottom on which the bag rests, two side walls, an area stiffening and gripping connecting the two side walls and a front face also connecting the two side walls, said front face corresponding to the side where the pouring of the contents of the bag after opening thereof.

Sachets of this type are known per se. They were, for example, but not limited to, the subject of patent applications in FRANCE 75-18258, 78-04233, 80-02187, 83-18257 in the name of the applicant, requests to which express reference is made here.

These sachets give complete satisfaction and the results announced in the aforementioned requests are obtained.

For large-capacity sachets, however, it appeared that it was still necessary to perfect the stability of the sachet to avoid it overturning on the sides or tilting forwards.

The present invention proposes to remedy these drawbacks.

This result is obtained with a flexible plastic bag of the type obtained from at least one strip of plastic film shaped so as to determine by soldering a bottom on which the bag rests, two side walls, a zone of stiffening and gripping connecting the two side walls and a front face also connecting the two side walls, said front face corresponding to the side where the contents of the sachet are poured after opening thereof characterized in that the front face is provided with a means of stiffening and stabilizing the bag.

The holding and stabilizing means may consist, for example, of a rigid buttress. Said buttress can be of any material, for example cardboard, PVC, or any other synthetic material.

the buttress may also fulfill other functions, such as for example cooperating in the closure of the bag.

According to another embodiment, the holding means will consist of one or more vertical stiffening ribs formed at the level of said lateral face.

According to another embodiment of the invention, the stiffening and stabilization means is produced by the formation of folds on the front edges of the bag or by the addition of stiffening or structuring elements on said edges.

• - modification de la structure du film,
• - apport d'élément formant surépaisseur, donc rigidification.

Rigidity can therefore be obtained by two essential means:

• - modification of the structure of the film,
• - contribution of element forming additional thickness, therefore stiffening.

These two means can be applied or implemented inside or outside the sachet.

The invention also relates to methods for providing said sachets with said holding and stabilization means.

• - la figure 1 est une vue perspective avant d'un sachet conforme à l'invention avec contrefort ;
• - les figures 2 à 5 illustrent des sachets du type de celui de la figure 1 avec des formes de contreforts différentes ;
• - la figure 6 est une vue perspective arrière d'un sachet avec poignée de préhension de forme complémentaire à celle du contrefort de la figure 1 ;
• - la figure 7 illustre un contrefort oblong occupant toute la face frontale du sachet ;
• - les figures 8 et 9 montrent, agrandie, la conformation de la figure 7, qui coopère à la fermeture du sachet ;
• - la figure 10 illustre un contrefort oblong comportant un moyen de fermeture du sachet ;
• - les figures 11 et 12 montrent, agrandie, la conformation de la figure 10 en illustrant le mode de fermeture du sachet ;
• - la figure 13 est une vue en perspective d'un sachet conforme à l'invention avec deux nervures frontales de rigidification ;
• - la figure 13 A est une coupe transversale selon A-A du sachet de la figure 13 ;
• - la figure 14 est une vue en perspective d'un sachet conforme à l'invention avec une nervure frontale de rigidification ;
• - la figure 14 B est une coupe transversale selon B-B du sachet de la figure 14 ;
• - la figure 15 représente une machine pour la conformation des nervures des sachets des figures 13 et 14 ;
• - les figures 15 A, 15 B et 15 C sont des coupes transversales de la machine de conformation de la figure 15 respectivement selon A-A, B-B et C-C ;
• - la figure 16 est une vue perspective d'un sachet conforme à l'invention avec rigidification des arétes frontales ;
• - les figures 17 à 25 illustrent de manière schématique divers mode de mise en oeuvre permettant d'obtenir la rigidification désirée aux niveaux des arêtes frontales du sachet ;
• - la figure 26 est une vue schématique d'un dispositif pour l'obtention des sachets des figures 16 à 25 ;
• - la figure 27 est une vue schématique en coupe illustrant un mode particulier de mise en oeuvre du dispositif de la figure 26 correspondant au sachet de la figure 17.

The invention will be better understood with the aid of: the description below made with reference to the appended drawings in which:

• - Figure 1 is a front perspective view of a bag according to the invention with buttress;
• - Figures 2 to 5 illustrate sachets of the type of that of Figure 1 with different buttress shapes;
• - Figure 6 is a rear perspective view of a bag with grip handle of shape complementary to that of the buttress of Figure 1;
• - Figure 7 illustrates an oblong buttress occupying the entire front face of the bag;
• - Figures 8 and 9 show, enlarged, the conformation of Figure 7, which cooperates in the closure of the bag;
• - Figure 10 illustrates an oblong buttress comprising a means for closing the bag;
• - Figures 11 and 12 show, enlarged, the conformation of Figure 10 illustrating the method of closing the bag;
• - Figure 13 is a perspective view of a bag according to the invention with two front stiffening ribs;
• - Figure 13 A is a cross section along AA of the bag of Figure 13;
• - Figure 14 is a perspective view of a bag according to the invention with a front stiffening rib;
• - Figure 14 B is a cross section along BB of the bag of Figure 14;
• - Figure 15 shows a machine for shaping the ribs of the bags of Figures 13 and 14;
• - Figures 15 A, 15 B and 15 C are cross sections of the shaping machine of Figure 15 respectively according to AA, BB and CC;
• - Figure 16 is a perspective view of a bag according to the invention with stiffening of the front edges;
• - Figures 17 to 25 schematically illustrate various modes of implementation to obtain the desired stiffening at the front edges of the bag;
• - Figure 26 is a schematic view of a device for obtaining the sachets of Figures 16 to 25;
• FIG. 27 is a schematic sectional view illustrating a particular embodiment of the device of FIG. 26 corresponding to the bag of FIG. 17.

We will first refer to Figure 1.

• - deux parois latérales telles que (2) ;
• - un fond (3) sur lequel il est appelé à reposer ;
• - une zone de rigidification et de préhension (4) reliant entre elles les deux parois latérales (2) ;
• - une face frontale (5) relaint également entre elles les deux parois latérales (2) ;

est muni, conformément à l'invention, d'un moyen de rigidification et de stabilisation.According to this embodiment of the invention, a sachet (1) essentially comprising:

• - two side walls such as (2);
• - a bottom (3) on which it is called to rest;
• - a stiffening and gripping zone (4) connecting the two side walls (2) together;
• - a front face (5) also passes between them the two side walls (2);

is provided, in accordance with the invention, with a stiffening and stabilization means.

• - d'un contrefort rigide (6)
• - et/ ou d'une ou plusieurs nervures verticales (7). Le contrefort sera disposé préférentiellement de manière telle que sa base (6') puisse, lorsque le sachet est posé sur une surface plane, prendre appui sur ladite suface plane.

It could be :

• - a rigid buttress (6)
• - And / or one or more vertical ribs (7). The buttress will preferably be arranged in such a way that its base (6 ′) can, when the sachet is placed on a flat surface, bear on said flat surface.

It may be of any material, for example synthetic material, possibly recycling to limit the cost price, cardboard, etc., this in a nonlimiting manner.

• - forme hemi-circulaire, comme représenté à la figure 1 ;
• - forme quadrangulaire (7), comme représenté à la figure 2 ;
• - forme trapézoïdale (8), éventuellement tronquée, comme représenté à la figure 3 ;
• - forme évidée (9), en fer à cheval, comme représenté à la figure 4 ;
• - forme trapézoidale (10), comme représenté à la figure 5, les angles de base étant rabattus contre les parois latérales pour renforcer encore la stabilisation.

It may also affect any form compatible with the outsourced function, such as for example, but not limited to:

• - semi-circular shape, as shown in Figure 1;
• - quadrangular shape (7), as shown in Figure 2;
• - trapezoidal shape (8), possibly truncated, as shown in Figure 3;
• - hollowed out shape (9), made of horseshoe, as shown in FIG. 4;
• - trapezoidal shape (10), as shown in Figure 5, the base angles being folded against the side walls to further enhance stabilization.

It will be noted that, in all the proposed forms of illustration, there is a contact line respectively (6 ', 7', 8 ', 9' 10 ') between the buttress (6, 7, 8, 9, 10) and the surface on which the bag which is provided with it rests.

Optionally, as shown in FIG. 6, provision may be made for the buttress (6), for the sake of saving material, to be cut from the element (11) applied in the stiffening and gripping zone (4 ) above.

Other forms of front buttress may be used, which advantageously fulfill, in addition to the desired function, namely stiffening and stabilization of the bag, one or more complementary functions.

Thus it can be very advantageously envisaged that the buttress cooperates in the closing of the bag, once it has been opened.

In the embodiment of Figures 7, 8 and 9 to which we will now refer, the buttress is generally oblong and trapezoidal. It is made integral with the bag (1) by two welding or bonding lines (13, 14) arranged one (13) substantially at the base of the front face, the other (14) slightly offset from the upper part of said buttress (12), thus determining an area (15) open on 3 sides and in particular in the direction of the top of the bag where the pouring opening (16) is to be made.

This structure of the upper part of the bag is shown, enlarged, in FIG. 8.

To close the bag after a first use, the upper horn (17) comprising the opening (16) is folded against the buttress (12) and inserted between the zone (15) and the front face of the bag, as shown in the figure 9.

In the variant of FIGS. 10, 11 and 12, the function of which is completely identical to the previous one, the bag comprises a buttress (18) provided at its upper part with means (19) for closing and pinching the horn. upper (17) of the bag. As shown in Figure 11 the means (19) consists essentially of two legs (20,21) substantially symmetrical relative to the longitudinal axis of the buttress (18) and cooperating with a finger (22) disposed between ..said legs .

The closure is obtained by folding the upper horn (17) of the bag so as to arrange it over the tabs (20,21), under the finger (22 ;, where it is held by the clamping effect thus obtained.

The buttress of the type described above and shown in Figures 1 to 12 may be attached to the bag by any means, such as welding or gluing, at any time during the process of manufacturing and filling the bag.

For example, the buttress (6, 7, 8, 9, 12, 18) can be added by a process analogous to that making it possible to fix the stiffening and gripping element (11), as described by way of example in patent application in FRANCE No. 83-18257 in the name of the applicant.

According to a second embodiment, the stiffening and stabilization means may consist of one or more vertical ribs (7), already shown in FIG. ₁ . In this representation, these ribs (7) are used in conjunction with a buttress such as (6) of the type illustrated in the foregoing.

The rib (s) (7) can also alone contribute to obtaining the desired result, namely stiffening and stabilization of the sachet.

Thus in Figures 13 and 13 A, there is shown a bag (1 ') provided with two vertical front ribs (23,24) of this type.

Advantageously, the lower edge of the front face of the bag (1 ′) in contact with the surface on which it is arranged will also be reinforced by a weld (25).

FIGS. 14 and 14 B show a mode of implementation of the same type as the previous one, but with a single stiffening and stabilization rib (26), possibly reinforced by a weld (27) on the lower edge of the front face.

The ribs (23, 24, 26) can be produced, by way of nonlimiting example, using the following device.

On a conformator (28) of a type known to a person skilled in the art, on which a film (29) is made to conform into a continuous roll (30), then to be filled with the liquid to be packaged and transformed into sachets or individual cushions, inter alia by means of a central cannula (31), intervention and shaping stations of the rib (s) (23, 24, 26) are provided.

Take the example of making two ribs (23,24).

At a first station (32) the film being at this stage ready to be welded in order to be transformed into a continuous rod (30), a former (33) through which the film passes gives it a W shape.

• - à la soudure du film (29) pour le conformer en boudin (30) de manière classique, par une mâchoire de soudage (35).
• - à la soudure du pli en W précité au niveau de ses deux arêtes (36,37) par deux éléments de soudure (38,39), un élément isolant (40) étant interposé pour éviter la soudure des deux arêtes (36,37) entre elles.

At the station (34) arranged downstream thereof, one proceeds jointly or successively:

• - Welding the film (29) to conform it into a tube (30) in a conventional manner, by a welding jaw (35).
• - at the welding of the aforementioned W-fold at its two edges (36,37) by two welding elements (38,39), an insulating element (40) being interposed to avoid the welding of the two edges (36,37 ) between them.

Finally, a post (41) arranged downstream is provided with two spacer fingers (42, 43) which unfold the zone shaped as W so as to give it the desired structure to form the front face of the future sachet.

Reference will now be made to FIG. 16. The bag (101), according to the invention, has on its front face (102) two edges (103, 104) which are stiffened to give the bag stability and shape.

This result is obtained either by the formation of folds or by the addition of stiffening or structuring elements at the level of said edges.

These elements are added to the surface on the sheath forming the bag by gluing, sealing, welding or any other suitable process.

As will be illustrated later, said elements will be single-material or composite, flat or angular, etc.

Thus there is shown in Figure 17 a reinforcement (105) attached externally to the bag and forming an angle whose apex marks the edge of the bag. The opening angle of the reinforcement (105) can be arbitrary. We can also consider giving it a certain elasticity so that the angle remains well marked even when the bag is completely filled.

FIG. 18 shows a similar structure with external reinforcement (106), which is applied to the edge by enveloping an insert (107) disposed parallel to said edge. The insert can be made of any material.

In the embodiment of FIG. 19, the reinforcement (108) is obtained by pinching the edge of the bag, as illustrated above.

In FIG. 20, the same result is obtained by fitting a bead (109) along the edge.

In Figure 21, the edge is marked along the edge of a reinforcing strip (110).

In FIG. 22, the angle of the external reinforcement (111) is pinched, which accentuates the marking of the edge.

Finally, the embodiment shown in FIG. 23 shows an external reinforcement (112) folded back on itself, determining a longitudinal cavity (113) which can be empty or inflated, thus accentuating the stiffening.

In the embodiments illustrated in FIGS. 24 and 25, it is the film constituting the sachet which is weakened, either internally (114) or externally (115).

Folding can be obtained in this case by hot or cold punching.

Reference will now be made to FIGS. 26 and 27 which illustrate a device making it possible to obtain the embodiments "of FIGS. 17 to 23.

The laying of the stiffening element will preferably be done when the film is shaped from a sheath on a shaper foreshadowing the shape and dimensions of the finished package. A feeding system will convey the stiffening element which will be affixed at the level of the shaper on the film sheath.

Thus, the bags according to the invention are obtained from a sheath (116) which passes over a matrix (117). This matrix comprises, to form the front edges, one or more conformers (118).

At the level of the shaper (118), the stiffening element (119) is applied by welding, gluing or sealing from a supply coil (120), by means of a suitable device (121) whose nature is linked to the method of attachment, namely welding, gluing or sealing. The device (121) will for example include a head (122) of profile complementary to that of the shaper (118).

The system will operate in an alternative manner, that is to say that when a bag is being filled, the film advance is stopped and the device applies a stiffening element on a bag in the process of being shaped.

The stiffening element will be cut automatically before or during installation to the necessary length, for example the length of the edge corresponding to the filled and closed bag.

According to an alternative embodiment, provision will also be made to reinforce the upper edges of the bag, as represented by the reference (123). The structure of this horizontal reinforcement will be identical to that illustrated in FIGS. 17 to 25 for the vertical reinforcement.

The installation will be carried out as illustrated in FIG. 26, from a power supply (124) and according to a procedure completely similar to that described above for the vertical reinforcement.

It will be understood that the invention applies to all modes of implementation, regardless in particular of the nature of the materials used.

Claims (20)

1. Flexible plastic bag of the type obtained from at least one strip of plastic film shaped so as to determine by soldering a bottom (3) on which the bag rests, two side walls (2), a stiffening and gripping area (4) connecting the two side walls (2), said front face corresponding to the side where the contents of the sachet take place after opening thereof, characterized in that the front face ( 5) is provided with a means of stiffening and stabilizing the sachet. 2. Bag according to claim 1, characterized in that the stiffening and stabilization means consists of a rigid buttress (6). 3. Bag according to claim 1, characterized in that the buttress (6) is arranged so that its base (6 ') can, when the bag is placed on a flat surface, bear on it. 4. Bag according to any one of claims 2 and 3, characterized in that it affects a shape chosen from the group comprising the semi-circular (6), quadrangular (7), trapezoidal (8), truncated trapezoidal shapes, hollowed out in horseshoe (9), trapezoidal (10) with folded base angles. 5. Bag according to any one of claims 2 to 4, characterized in that the buttress (6) is cut in the element (11) applied in the stiffening and gripping zone (4). 6. Bag according to any one of claims 2 to 5, characterized in that the buttress further cooperates in the closing of the bag. 7. Bag according to claim 6, characterized in that the buttress is of generally oblong shape and that it is made integral with the bag (1) by two welding or bonding lines (13, 14) arranged one (13 ) substantially at the base of the front face, the other (14) slightly offset from the upper part of said buttress (17), determining thus a zone (15) open on 3 sides and in particular towards the top of the bag where the pouring opening (16) must be made. 8. Bag according to claim 6, characterized in that the buttress (18) is provided at its upper part with means (19) for closing and pinching the upper horn of the bag, the means (19) consisting essentially of two legs (20, 21) substantially symmetrical with respect to the longitudinal axis of the buttress (18) and cooperating with a finger (22) disposed between said legs. 9. Bag according to any one of claims 1 to 8 characterized in that the stiffening and stabilization means consists of at least one vertical rib (23,24; 26). 10. Device for shaping a sachet according to claim 9, of the type in which a film (29) is transformed into a continuous rod (30) on a former (28) then is filled with the liquid to be conditioned and is transformed into sachets or individual cushions, characterized in that it also comprises the following successive items: a station (32) consisting of a former (33) through which the film passes and which gives it a W shape, - A station (34) arranged downstream from the previous one, in which, in addition to the welding of the film (29) in order to conform it into a bead (30), the W-fold is welded at its two edges (36, 37) in pairs welding elements (38,39) an insulator (40) being interposed to avoid welding the two edges (36,37) together, - A post (41) arranged downstream is provided with two spacer fingers (42, 43) which unfold the zone shaped as W so as to give it the desired structure to form the front face of the future bag. 11. flexible plastic bag according to claim 1, characterized in that the stiffening and stabilization means is produced by the formation of folds on the front edges of the bag or by providing stiffening or structuring elements on said edges. 12. Bag according to claim 11, characterized in that the stiffening element is an external reinforcement (105) 'forming an angle whose apex marks the edge of the bag. 13. Bag according to claim 12, characterized in that the reinforcement (106) further comprises an insert (107). 14. Bag according to claim 12, characterized in that the angle of the reinforcement (111) is pinched. 15. Bag according to claim 11, characterized in that the reinforcement consists of a cord (109) added along the edge to be reinforced. 16. Bag according to claim 11, characterized in that the edge is marked along the edge of a reinforcing strip (110). 17. Bag according to claim 11, characterized in that the external reinforcement (112) is folded back on itself, determining a longitudinal cavity (113) which can be empty or inflated. 18. Bag according to claim 11, characterized in that the edge is marked by the weakening of the film of the bag, internally (114) or externally (115). 19. Bag according to any one of claims 11 to 18 characterized in that the upper edges (123) are also reinforced by a stiffening means. 20. Device for producing a bag according to any one of claims 11 to 19, characterized in that it essentially comprises: - a supply of stiffening element (119), - a matrix (117) for shaping the film sheath (116), - a shaper (118) cooperating with a device (121) comprising a head (122) of profile complementary to that of the shaper (118) for securing the stiffening element of the sheath by welding, gluing or sealing.

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