EP0197875B1 - Flexible synthetic bag comprising a means for rigidification and stabilisation - Google Patents

Abstract

The front face of a bag, made of flexible material obtained from a strip of synthetic film shaped to define a bottom and a pair of side walls connected by a stiffening and gripping zone to the front face, from which contents of the bag are poured, is provided with structure for stiffening and stabilizing said bag.

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, a dorsal face forming stiffening and gripping zone connecting the two side walls, a front face corresponding to the side where the pouring of the contents of the bag takes place after opening it and which is provided with a means of stiffening and stabilization of the bag.

Similar sachets are known per se. They have, for example, but not limited to, been the subject of patent applications in France 2314327, 2417445, 2474457, 2554785 in the name of the applicant, requests to which reference is made here expressly.

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.

Likewise, US-A-3462067 describes a sachet of the type described above, but which does not allow the sachet to be closed after a first use.

The present invention proposes to remedy these drawbacks.

According to a first embodiment of the invention, a bag of the above type is proposed, in which the means consists of a buttress of generally oblong shape and is made integral with the bag by two lines of welding or bonding one arranged substantially at the base of the front face, the other slightly offset from the upper part of said buttress, thus determining an area open on 3 sides and in particular towards the top of the bag where the pouring opening.

According to a second implementation variant, the buttress means is provided at its upper part with means for closing and pinching the upper horn of the bag through which said pouring takes place, this latter means consisting essentially of two legs substantially symmetrical with respect to the longitudinal axis of the buttress and cooperating with a finger disposed between said legs.

• - la figure 1 est une vue perspective avant d'un sachet avec contrefort;
• - les figures 2 à 5 illustrent des sachets du type de celui de la figure 1 avec des formes de contrefois 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 selon une première forme de réalisation de l'invention;
• - 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 selon une deuxième forme de réalisation de l'invention;
• - 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 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 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 avec rigidification des arêtes 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 using the description below made with reference to the appended drawings in which:

• - Figure 1 is a front perspective view of a bag with buttress;
• - Figures 2 to 5 illustrate sachets of the type of that of Figure 1 with different forms of counterfeit;
• - 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 according to a first embodiment of the invention;
• - 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 means for closing the bag according to a second embodiment of the invention;
• - 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 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 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 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.

• - 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 d'un moyen de rigidification et de stabilisation. Il peut s'agir:
• -d'un contrefort rigide (6)
• - et/ou d'une ou plusieurs nervures verticales (7).

Firstly, reference is made to FIG. 1. According to this embodiment, a bag (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 with a means of stiffening and stabilization. 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 of recycling to limit the cost price, of cardboard, etc., this in a nonlimiting manner.

• - forme semi-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 trapézoïdale (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 forms of illustration proposed, there is a line of contact 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 may be in accordance with the invention envisaged that the buttress cooperates in the closure of the bag, once it has been opened.

In the embodiment according to the invention 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 gluing 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 upper horn (17) of the sachet. As shown in Figure 11 the means (19) consists 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.

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 Figure 1. In this representation, these ribs (7) are used in conjunction with a buttress such as (6) of the type illustrated in the above.

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 an embodiment 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) may be produced, by way of nonlimiting example, using the following device.

On a conformator (28) of a type known to those skilled in the art, on which a film (29) is made to be shaped into a continuous rod (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) disposed downstream is provided with two spacer fingers (42, 43) which unfold the zone shaped as W so as to give it the structure sought to form the front face of the future sachet.

We will now refer to FIG. 16. The bag (101) 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 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.

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 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), the nature of which is related 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. 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 made from a power supply (124) and according to a procedure completely similar to that described above for the vertical reinforcement.

Claims (3)

1. Sachet of flexible synthetic material of the type produced from at least one band of synthetic material sheet, shaped in such a manner as to determine by seals (welds) a base (3), on which the sachet rests, two lateral walls (2), a rear face forming a stiffening and gripping zone (4) connecting together the two lateral walls (2), a front face corresponding to the side where pouring of the contents of the sachet takes place after it has been opened and which is equipped with a means for stiffening and stabilizing the sachet, characterized in that the means consists of a buttress of generally oblong form which is firmly attached to the sachet (1) by two lines of sealing (welding) or gluing (13,14) disposed, the one (13) substantially at the base of the front face, the other (14) slightly set back with respect to the upper part of said buttress (17), thus determining a zone (15) open on three sides and especially towards the top of the sachet, where the pouring opening (16) is to be formed.

2. Sachet of flexible synthetic material of the type produced from at least one band of synthetic material sheet, shaped in such a manner as to determine by seals (welds) a base (3), on which the sachet rests, two lateral walls (2), a rear face forming a stiffening and gripping zone (4) connecting together the two lateral walls (2), a front face corresponding to the side where pouring of the contents of the sachet takes place after it has been opened and which is equipped with a means for stiffening and stabilizing the sachet, characterized in that means consists of a buttress (18), equipped in its upper part with a means (19) for closing and pinching the upper corner of the sachet through which said pouring takes place, this latter means (19) being composed essentially of two tabs (20, 21), substantially symmetrical about the longitudinal axis of the buttress (18) and cooperating with a finger (22) disposed between said tabs.

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