EP1000559B1 - Bag with zip-lock closure actuated by a slider - Google Patents

Description

The present invention relates to the field of sachets comprising complementary closure profiles actuated respectively on opening and closing by a cursor.

Such bags are described for example in the documents EP-A-0051010 , EP-A-0102301 and EP-A-0479661 .

Generally the sliders comprise two lateral wings interconnected at a base and defining, with an elongated central sole placed between the closure profiles, two convergent passageways for the complementary interlocking closure profiles. Thus, when the relative direction of movement of the slider with respect to the closure profiles tends to move the slider by forcing the closure profiles into engagement, the bag is closed. On the contrary, when the cursor is moved in the opposite direction, the bag is opened, thanks to the central sole which separates the closure profiles.

These pouches operated at the opening and closing by a slider have already rendered great services.

The sliders facilitate the opening and closing of the bags. The presence of a cursor is particularly appreciated by the elderly or visually impaired.

However, the majority of known slider sachets are not completely satisfactory. In particular most of these bags do not have a total seal in the closed position of the profiles. This leakage is due to the fact that the profiles remain separate, in front of the slider, due to the presence of the central sole placed between the closure profiles.

Sealing is nevertheless required in many applications, including but not limited to the bags used for freezing food products.

An attempt has been made to overcome this drawback by making a cut in the closure strips or in the film, near the end receiving the slider in the closed position of the bag, so that the sole the slider penetrates into this slit or is located between film portions independent of the closure profiles, and allows a perfect engagement of the profiles over their entire length, in the closed position. An example of such means can be found in the documents US Patent 5067208 , US Patent 5442837 and US Patent 5020194 .

Nevertheless, the means proposed in this context are very complex. They do not always allow a perfect tightness of the bags. In addition, they have the major disadvantage of not holding the cursor perfectly and consequently of causing for example a risk that the cursor is ingested by young children.

Other solutions have also been proposed in which the central sole of the slider is mounted to move thereon between an active position in which said soleplate is placed between the closure profiles, and a retracted position in which the sole is removed from the closing profiles. An example of such means can be found in the document WO-A-98/23493 .

These latter solutions theoretically make it possible to improve the tightness of the sachets. However in practice they are too complex, since sealing is not ensured if the user forgets to move the sole of the cursor in the retracted position. In addition, these solutions sometimes prove unreliable, insofar as after many manipulations, the sole can be permanently separated from the slider.

The document FR-A-2761956 discloses a bag having complementary slider-actuated closing profiles, which comprises means adapted to provide a seal between the inner walls of the bag, in the closed position thereof, in the area of the bag underlying the profiles at the level of the end thereof receiving the cursor in the closed position. The document FR-A-2761956 describes different embodiments. According to a first embodiment, the means ensuring the seal are formed by a weld between the inner walls of the bag, in the area underlying the profiles at the end thereof receiving the slider in the closed position. According to a second embodiment, the means ensuring the seal are formed by a boss between the inner walls of the bag, in the area underlying the profiles at the end thereof receiving the slider in the closed position. According to a third embodiment, the means ensuring the seal are formed by pinching means provided on the slider, adapted to clamp the area underlying the profiles at the end thereof receiving the slider in position closed. According to a fourth embodiment, the means ensuring the seal are formed by a closure or baffle located under a first closure adjacent to the mouth of the bag and closing by the action of the cursor, the end corresponding to the cursor in closed position, the second closure or baffle being probed to seal.

It is now an object of the present invention to improve the performance of known slider bags.

The main object of the present invention is to provide pouches having a greater seal than previous known bags.

Another object of the present invention is to provide means limiting the risk of inadvertent withdrawal of the cursor, in particular to limit the risk of ingestion by young children.

Another object of the present invention is to provide means for a high rate of productivity in automatic.

These objects are achieved within the framework of the present invention by means of a bag as defined in appended claim 1 which is delimited in the preamble and characterizing part with respect to the document FR-A-2,761,956 .

• les figures 1 à 3 représentent trois vues schématiques en coupe transversale d'un sachet équipé d'un curseur conforme à la présente invention, selon des vues référencées respectivement I-I, II-II et III-III sur la figure 4,
• la figure 4 représente une vue en coupe longitudinale médiane d'un curseur conforme à la présente invention, selon le plan de coupe référencé IV-IV sur les figures 1 à 3,
• la figure 5 représente une autre vue en coupe longitudinale du curseur selon le plan de coupe référencé V-V sur la figure 4,
• les figures 6 à 16 illustrent selon des vues en coupe transversale similaires à la figure 1, une première série de variantes de réalisation conformes à la présente invention,
• les figures 17 à 34 illustrent une seconde série de variantes de réalisation conformes à la présente invention, et
• les figures 35 à 44 illustrent une troisième série de variantes de réalisation conformes à la présente invention.

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 as non-limiting examples and in which:

• FIGS. 1 to 3 show three schematic cross-sectional views of a bag equipped with a slider according to the present invention, according to views respectively referenced II, II-II and III-III in FIG. 4,
• FIG. 4 represents a view in median longitudinal section of a slider according to the present invention, according to the section plane referenced IV-IV in FIGS. 1 to 3,
• FIG. 5 represents another longitudinal sectional view of the slider according to the section plane referenced VV in FIG. 4,
• FIGS. 6 to 16 illustrate, in cross-sectional views similar to FIG. 1, a first series of variant embodiments according to the present invention;
• FIGS. 17 to 34 illustrate a second series of variant embodiments in accordance with the present invention, and
• Figures 35 to 44 illustrate a third series of alternative embodiments according to the present invention.

FIGS. 1 to 3 diagrammatically show a bag 10 whose mouth is referenced 12 and the bottom 14.

The bag 10 is composed of two main sheets 16, 18. These are interconnected at the bottom 14 (by folding, the two sheets 16, 18 being integral with the origin as shown in Figures 1 to 3, or by welding or gluing, the two sheets 16, 18 being initially separated and superimposed on the production as illustrated in FIGS. 9 to 14, or else by welding or gluing the edges of a single sheet folded on itself at the level of the mouth, as illustrated for example in Figures 15 and 16), and at the two side edges perpendicular to the bottom 14 and the mouth 12 (the connection at the side edges is preferably provided by welding or gluing) .

At the mouth 12, the two sheets 16, 18 are provided with complementary closure profiles 20, 22.

These complementary closure profiles 20, 22 may be the subject of many embodiments. The invention is not limited to the specific embodiments illustrated in the accompanying figures. It will also be noted that two embodiments of such closure profiles 20, 22, respectively in FIGS. 1 to 8 and 17 and following on the one hand and in FIGS. 9 to 16, have been illustrated in the appended figures. on the other hand.

In particular, the invention applies to closing profiles 20, 22 of male and female type, respectively, as is well known to those skilled in the art and as shown schematically in FIGS. 1 to 8 and 17 and following. However, the invention is not limited to this particular arrangement and can also extend for example to hook-type closing profiles 20, 22 as illustrated in FIGS. 9 to 16.

As illustrated in FIGS. 1 to 6, 8 to 12 and 15 in particular the complementary closure profiles 20, 22 may have come extrusion on the sheets 16, 18 composing the bag (more precisely on the inner surface of these sheets 16, 18 according to the embodiments of Figures 1 to 6 and 8 to 12 and on the outer surface of these sheets according to the mode embodiment of Figure 15 when the sheets 16, 18 form, at the mouth of the bag, a bellow folded towards the inside of the bag to form a control veil opening).

However, according to an alternative embodiment, the closure profiles 20, 22 may initially be formed on respective support webs 21, 23 attached to the sheets 16, 18, at the mouth 12 of the bag, as has been described. FIGS. 7, 13, 14 and 16. Again, it should be noted that according to FIGS. 7, 13 and 14, the support webs 21, 23 are fixed on the inner surface of the sheets 16, 18. On the other hand, according to FIG. the sheets 16, 18 forming, at the mouth of the bag, a bellow folded towards the inside of the bag to form a control veil of opening, the support webs 21, 23 are fixed on the outer surface of the sheets 16, 18.

The connection between the webs 21, 23 and the films 16, 18 can be achieved by any suitable conventional means, for example by hot welding or gluing.

The use of closure profiles not extruded on the films 16, 18, but reported by welding or gluing is only illustrated in the accompanying drawings in FIGS. 7, 13, 14 and 16. However, the use of such closure profiles 20, 22 reported on the films 16, 18 can be applied to all of the embodiments according to the invention.

As indicated above, the bag further comprises a slider 50 whose role is to facilitate the openings and closures of the bag, by separation, respectively approximation, closure profiles, when the cursor is moved in translation at the level of the mouth of the bag.

The cursor 50 can be the subject of many embodiments. The cursor 50 can be in particular in accordance with the general provisions described in the document EP-A-0479661 .

Preferably, the slider 50, made of plastic material, comprises two lateral wings 52, 54 (or "flanks") connected to each other at a base 56 and which define with an elongate central soleplate 59, two passageways 590, 592 convergent for the interlocking complementary closure profiles 20, 22. Thus, when the relative direction of movement of the slider 50 with respect to the closing profiles 20, 22 tends to move the slider 50 by forcing the closure profiles 20, 22 into engagement , the bag is closed. When the cursor 50 is moved in the opposite direction, the bag is opened.

In the context of the present invention, as indicated above, the soleplate 59 is interrupted within (that is to say recessed) the longitudinal end of the slider, at least on the widest side of the slider corresponding to the diverging side of the corridors 590, 592, as seen in particular in Figures 1, 3, 4 and 5, and the lateral wings 52, 54 are provided in the vicinity of their free edge opposite the base 56, means 520, 540 for biasing the sheets 16, 18 of the bag in approach, covering the entire longitudinal extent of the soleplate 59 and extending beyond longitudinally on either side thereof, to ensure the sealing of the bag in position closed of it.

According to the preferred embodiment illustrated in Figures 1 to 4, these biasing means are composed of ribs 520, 540 projecting towards the inside of the slider 50, at the edge of the wings 52, 54 opposite the base 56 , or where appropriate on a part of the height of the inner surface of these wings 52, 54 between the free edge of the wings 52, 54 and the base 56. Note that if the ribs 520, 540 are not located necessarily at the free edge of the lateral wings 52, 54, these ribs 520, 540 are, however, located below the soleplate 59 (that is to say between the top of the soleplate 59, opposite the base 56, and the free edge of the wings 52, 54), and not up to it.

These ribs 520, 540 continuously cover the sole 59 and extend beyond it, at least at the widest end of the sole 59 corresponding to the diverging side of the passages 590, 592. More specifically still according to the preferred embodiment illustrated in the accompanying figures, the ribs 520, 540 extend over the entire length of the slider 50, while the sole 59 is interrupted, at its widest end (diverging side of the corridors 590, 592), at a distance I1 from the end of the slider 50, and at its thinnest end (convergent side of the corridors 590, 592) at a distance I2 from the end of the slider 50.

The width I6 of the free space defined between the vertices of the ribs 520, 540 is substantially equal to the sum of the thicknesses of the sheets 16, 18, at the mouth of the bags. Thus, the slider 50 biases the sheets in proximity, below the soleplate 59, and ensures the sealing of the bag.

According to the embodiment illustrated in Figures 1 to 5 attached, there are provided two ribs 520, 540 symmetrical and the same height, one on each of the wings 52, 54. Alternatively, one can provide ribs 520, 540 unsymmetrical. Thus one can provide only a single rib on one of the wings 52, 54 of the slider 50.

• I3 la hauteur de la semelle 59, considérée parallèlement aux ailes 52, 54 et perpendiculairement à l'embase 56,
• I4 la distance séparant l'extrémité libre de la semelle 59 opposée à l'embase 56 et les nervures 520, 540, et
• I5 la largeur de la semelle 59, au niveau de son extrémité la plus large.

In the figures, reference is made to:

• I3 the height of the soleplate 59, considered parallel to the flanges 52, 54 and perpendicularly to the base 56,
• I4 the distance separating the free end of the sole 59 opposed to the base 56 and the ribs 520, 540, and
• I5 the width of the sole 59, at its widest end.

• I1 est de préférence compris entre 1 mm et 10mm, et est très préférentiellement de l'ordre de 3mm.
• I2 est de préférence compris entre 0,5mm et 10mm, et est très préférentiellement de l'ordre de 4mm.
• I3 est de préférence compris entre 2mm et 7mm, et est très préférentiellement de l'ordre de 3mm.
• I4 est de préférence compris entre 5mm et 15mm, et est très préférentiellement de l'ordre de 8mm.
• I5 est de préférence compris entre 0,3mm et 2mm, et est très préférentiellement de l'ordre de 0,5mm.
• I6 est de préférence compris entre 50µm et 2,5mm, et est très préférentiellement de l'ordre de 200µm.

In the context of the present invention:

• I1 is preferably between 1 mm and 10 mm, and is very preferably of the order of 3 mm.
• I2 is preferably between 0.5mm and 10mm, and is very preferably of the order of 4mm.
• I3 is preferably between 2mm and 7mm, and is very preferably of the order of 3mm.
• I4 is preferably between 5mm and 15mm, and is very preferably of the order of 8mm.
• I5 is preferably between 0.3 mm and 2 mm, and is very preferably of the order of 0.5 mm.
• I6 is preferably between 50 .mu.m and 2.5 mm, and is very preferably of the order of 200 .mu.m.

• le rapport I1/I5 est de préférence compris entre 0,5 et 30, et est très préférentiellement de l'ordre de 6.
• le rapport I2/I5 est de préférence compris entre 2,5 et 30, et est très préférentiellement de l'ordre de 8.
• le rapport I1/I3 est de préférence compris entre 0,5 et 5, et est très préférentiellement de l'ordre de 1.
• le rapport I2/I3 est de préférence compris entre 0,1 et 5, et est très préférentiellement de l'ordre de 1,3.
• le rapport I1/I4 est de préférence compris entre 0,05 et 2, et est très préférentiellement de l'ordre de 0,4.
• le rapport I2/I4 est de préférence compris entre 0,05 et 2, et est très préférentiellement de l'ordre de 0,5.

In addition, in the context of the present invention:

• the ratio I1 / I5 is preferably between 0.5 and 30, and is very preferably of the order of 6.
• the ratio I2 / I5 is preferably between 2.5 and 30, and is very preferably of the order of 8.
• the ratio I1 / I3 is preferably between 0.5 and 5, and is very preferably of the order of 1.
• the ratio I2 / I3 is preferably between 0.1 and 5, and is very preferably of the order of 1.3.
• the ratio I1 / I4 is preferably between 0.05 and 2, and is very preferably of the order of 0.4.
• the ratio I2 / I4 is preferably between 0.05 and 2, and is very preferably of the order of 0.5.

In the context of the present invention, other means may be substituted or combined with the aforementioned ribs or bosses 520, 540 for biasing the sheets 16, 18 of the bag in approach.

Thus it may be provided, parallel to the closure profiles 20, 22, between said sheets 16, 18 and at the mouth 12 of the bag, additional relief means 100 secured to the bag designed to ensure sealing by forming a dam between the sheets 16, 18, in the closed position of the bag, said additional relief means 100 being placed facing the flanks 52, 54 of the slider 50 to be urged towards their sealing position by the slider 50 when it is moved to the sealing position.

The films 16, 18, the closure profiles 20, 22 and the additional sealing means 100 may be made of any suitable plastic material known to those skilled in the art. Preferably, it is polyolefin, very advantageously low or high density polyethylene, or even polypropylene.

Preferably in the context of the present invention, the means 100 are arranged on the inside of the closure profiles 20, 22 (at say inwardly of the bags with respect to these closure profiles 20, 22) and extend over the entire length of the bags (ie they have the same length as the closure profiles 20, 22) .

According to the embodiment illustrated in Figure 6, said additional sealing means 100 are formed of a bead 102 parallel to the section 20 and secured to one of the sheets 16. According to Figure 6 this bead 102 has come from extrusion on the film 16. Alternatively, however, as mentioned above, the bead 102 could have come from extrusion on a support veil attached to this film 16.

Such a bead 102 is placed opposite the flanks 52, 54 of the slider 50 and on the inside thereof. Thus the bead 102 is urged against the opposite film 18 when the slider 50 is moved to the closed position.

Preferably the geometry of the profiles 20, 22, means 100 and the slider 50 is such that the flanks 52, 54 of the slider 50 impose on the means 100, a transverse clearance (ie perpendicular to the sheets 16, 18) lower than that tolerated for the closure profiles 20, 22.

For this, for example when the internal surfaces of the sidewalls are parallel as shown in the accompanying figures, the thickness L1 of the means 100 is greater than that L2 defined by the closure profiles 20, 22 when they are engaged.

This preferential relationship L1> L2 is not limited to the embodiment of FIG. 6 but applies to all the embodiments of the present invention, including when said sealing means 100 are formed of two beads. or complementary male / female means or any other equivalent means, as will be described later.

This arrangement makes it possible to guarantee that the means 100 ensures a tight barrier between the two films 16 and 18.

According to the embodiment illustrated in Figure 7, the sealing means 100 are formed of two beads 104, 106 secured respectively to the two films 16 and 18 and placed in contact to come into contact with their apex to form a watertight barrier, when they are solicited by the flanks 52, 54 of the slider 50. According to Figure 7, the two beads 104, 106 are symmetrical. However, alternatively, one can provide seals 104, 106 asymmetrical.

According to the embodiment illustrated in Figure 8, the sealing means 100 are formed of complementary elements 110, 112 male / female secured respectively to the inner surface of the two sheets 16, 18 of the bag. More precisely still according to FIG. 8, the female element 112 is formed of two lips 1120 and 1122 adapted to rest respectively on the flanks of the male element 110. According to FIG. 8, the two lips 1120, 1122 are symmetrical. However, alternatively, two asymmetrical lips 1120, 1122 can be provided. Moreover, the element mixing 110 is globally rounded.

The sealing means 100 illustrated in FIG. 9 are identical to those of FIG. 8. However, it will be noted that according to FIG. 9, the slider 50 has bosses 520, 540 placed on the internal surface of its flanks 52, 54. means 100 to ensure the solicitation of the latter in sealing position, when closing the bag. The geometry of such bosses 520, 540 can be many variations. Alternatively one can provide such bosses on the outer surface of the walls 16, 18, facing the slider, or such bosses on the walls of the bag and other bosses facing the slider 50.

FIG. 10 illustrates another variant embodiment in which the male element 110 has a substantially triangular section. Thanks to this structure, it is ensured that the contact between the flanks of the male element 110 and the lips 1120 and 1122 is reinforced when the male and female elements 110 and 112 are urged closer by the slider 50.

Note also that according to Figure 10, the two lips 1120 and 1122 of the female element 112 are asymmetrical. Preferably the lip 1120 located inwardly of the bag relative to the male member 110 is longer and more flexible than the second lip 1122 located towards the outside of the bag. Thus the internal pressure of the sachet, even optionally directly the contents thereof, such as a liquid content, biases the first lip 1120 elastically against the male element 110. By against the second lip 1122 resists such a force and therefore does not deviate from the male element 110.

As illustrated in FIGS. 6 to 11, the means 100 can be extruded onto the sheets 16, 18 composing the bag (more precisely on the inner surface of these sheets 16, 18 according to the embodiments of FIGS. 11 and on the outer surface of these sheets according to the embodiment of Figure 15 when the sheets 16, 18 form, at the mouth of the bag, a bellow folded towards the inside of the bag to form a control veil opening ).

However, according to an alternative embodiment, the means 100 may initially be formed on respective support webs 121, 123 attached to the sheets 16, 18, at the mouth 12 of the bag, as illustrated in the figures. 12 to 14 and 1. Again it will be noted that according to FIGS. 12 to 14, the support webs 121, 123 are fixed on the inner surface of the sheets 16, 18. On the other hand, according to FIG. 16, the sheets 16, 18 forming the mouth of the bag, a bellow folded towards the inside of the bag to form a control veil of opening, the support webs 121, 123 are fixed on the outer surface of the sheets 16, 18.

It will also be noted that, as illustrated in FIGS. 13, 14 and 16, the support webs 121 and 123 may respectively be merged with the support webs 21 and 23 of the closure profiles 20, 22.

The connection between the webs 121, 123 and the films 16, 18 can be achieved by any suitable conventional means, for example by hot welding or gluing.

The use of means 100 not extruded on the films 16, 18 but reported by welding or gluing is only illustrated in the accompanying drawings in FIGS. 12 to 14 and 16. However, the use of such means 100 reported on the films 16, 18 may apply to all of the embodiments of the invention.

FIG. 11 illustrates an alternative embodiment according to which on the one hand there are notches 160, 180 which open on the outer surface of the bag, respectively opposite the means 100, in this case respectively facing the female element 112 and the male element 110, and secondly ribs 522 and 542 projecting from the surface internal flanks 52 and 54 of the slider 50, which ribs 522 and 542 are adapted to penetrate respectively in said notches 160 and 180.

The cooperation thus defined between the notches 160, 180 and the ribs 522 and 542 makes it possible to improve the biasing of the means 100 by the slider 50. Indeed, it makes it possible to precisely locate the stressing zone due to the slider 50. It also makes it possible to safely retain the cursor 50 on the bag. This cooperation forbids any inadvertent withdrawal of the cursor 50.

The use of ribs 522 and 542 and complementary notches 160, 180 is only illustrated in the accompanying drawings in FIG. 11. However, the use of such ribs 522 and 542 and complementary notches 160, 180 may apply to all embodiments of the invention.

The embodiment of Figure 12 has been previously described. It differs essentially from the embodiments illustrated in the previous figures in that the means 100 are carried by respective support webs 121, 123 reported on the sheets 16 and 18, as indicated above.

The embodiment of Figure 13 has been previously described. It differs essentially from the embodiments illustrated in the previous figures in that the means 100 are carried by respective support webs 121, 123 coinciding with the support webs 21 and 23 of the profiles 20, 22 and reported on the sheets 16 and 18, as indicated previously.

It is the same for the embodiment illustrated in FIG. 14. However, in addition according to FIG. 14, the support webs 121, 21 and 123, 23 are interconnected by a loop 24. This is arranged on the inside the means 100 and has its concavity directed towards the outside of the bag.

Thus, these support webs 121, 21, 123, 23 and 24 form an anti-violation veil or opening indicator at the mouth 12. It is indeed necessary to break this veil 24 before accessing the interior of the bag. This anti-violation veil 24 is formed of a bellow folded towards the inside of the bag, at the mouth 12 in the continuity of the support webs 121, 21 and 123, 23.

FIGS. 15 and 16 show variant embodiments according to which such an anti-violation or opening control pad, referenced 19, is formed by a fold in the film constituting the main sheets 16, 18 of the bag. According to Figure 15 the profiles 20, 22 and the means 100 are molded on this film. On the other hand, according to FIG. 16, the profiles 20, 22 and the means 100 are carried by support webs 121, 21 and 123, 23 attached to the film.

Such bellows 19 directed towards the inside of the bag may be shaped by any appropriate known means, for example by means of a blade urging the bellows 19 inwardly between the sheets 16, 18, as is well known. of the man of the art.

Those skilled in the art will readily understand that in a conventional manner, it is appropriate to break the anti-violation veil 24 or 19 to access the product contained in the bag 10.

Thus, the condition of the veil 24 or 19 makes it possible to indicate whether an intervention has taken place or not on the bag 10.

In order to facilitate the opening of the web 24 or 19, it may be provided, in a manner known per se, with a line of weakness or pre-cut, for example at mid-width, as illustrated schematically under reference 190 on Figures 15 and 16.

The bags obtained in the context of the present invention offer numerous advantages over prior known bags.

In particular, they allow a high rate of productivity and a good sealing of the bags.

Moreover, the cooperation defined between the notches 160, 180 and the ribs 522, 542 of the sliders 50 makes it possible to avoid any inadvertent withdrawal sliders 50 under the effect of the pressure inside the bags or under the effect of a request by a user.

Where appropriate, in the context of the embodiments illustrated in Figures 15 and 16 for which there is provided an anti-violation veil 19 formed by a fold of the film constituting the bags, it is possible to provide a weld between the internal surfaces of the sheets main 16, 18 component bag and the sections 162, 182 forming the bellows corresponding to the anti-intrusion veil 19 as schematized as 60 in Figures 15 and 16.

Naturally, the present invention is not limited to the particular embodiments which have just been described, but extends to all variants that are in keeping with its spirit.

The bags according to the present invention can be made on any type of known and appropriate machines, especially on FFS type machines (Form, Fill and Seal), that is to say machines designed to perform automatically forming operations, filling and closing sachets.

Furthermore, the present invention applies equally well to implementations according to which the closure profiles are arranged longitudinally with reference to the running direction of the film, and to implementations according to which the closure profiles are arranged transversely.

Moreover, the present invention applies equally well to implementations according to which, the closure profiles are pre-equipped with the cursor when they are conveyed on the bag-forming machine, and with implementations according to which the cursor is later disposed on the profiles.

Note also that the present invention is not limited to the geometry of the notches 160, 180 and ribs 522, 542 illustrated in Figure 11 attached. Indeed, these notches 160, 180 and ribs 522, 542 can be the subject of many variants as to their cross section. Thus, for example, it is conceivable to give the notches 522, 542 a cross-section with convergent edges, for example in dovetail or rail-shaped (for example T or others). Such an arrangement enhances the maintenance of the cursor 50 on the bags.

As indicated above, preferably, in the context of the present invention, the sealing means 100 as well as the closure profiles 20, 22 extend over the entire width of the bag. By contrast, by definition, the cursor 50 extends only over a limited area of this width. Therefore, the slider 50 can not alone solicit the sealing means 100 permanently over their entire length.

As indicated above, to guarantee the seal, it can be envisaged to give the means 100 a thickness L1 greater than that L2 of the closure profiles 20, 22.

Other means may be provided to induce a transverse pressure P transverse to the walls 16, 18 on the means 100, in the closed position of the bag to ensure a good seal. This pressure P is shown diagrammatically in FIGS. 7 and 10. However, these arrangements can again be applied to all the embodiments in accordance with the present invention.

Thus, in the context of the present invention, according to a variant, the closure profiles 20, 22 are adapted to automatically provide such a bias P means 100 when the bag is closed.

Different geometries of the closure profiles 20, 22 can be selected for this purpose.

In the case of complementary closure profiles of the male / female type as illustrated in FIG. 7, an asymmetrical female profile may for example be provided, in particular such that L3 is less than L4, that is to say that the height or bulk L3 of the element 220 defining the inner lip of the female profile 22 is less than the height or space L4 of the element 222 defining the outer lip of the female profile 22.

Those skilled in the art will understand that thanks to this arrangement, the internal element 220 of the female profile 22 induces a stress on the sealing means 100 in the closed state of the bag, that is to say when the 'element male 20 is engaged with the female element 22 and the entire length of the means 100.

A similar effect can be obtained with an asymmetrical male profile (combined if necessary with a female profile 22 also asymmetrical as indicated above).

In the case of hook-type complementary closure profiles as illustrated in FIG. 10, provision may be made, for example, for the two complementary hooks C1, C2 located towards the inside of the bag to define in the assembled position a width L5 between the internal faces of the sheets. 16, 18 less than the width L6 taken between the same faces of the sheets 16, 18 at the pair of complementary hooks C3, C4 located towards the outside of the bag. This arrangement makes it possible to ensure the same constraint over the entire length of the means 100.

FIG. 17 illustrates an alternative embodiment according to which the two elements 104, 106 integral respectively with the internal surface of the sheets 16, 18 are not positioned to bear against their apex, as indicated previously with reference to FIG. 7, but are positioned to be juxtaposed and come to bear at their adjacent flanks opposite 103, 105 generally perpendicular to the sheets 16 and 18.

Note that preferably according to the embodiments illustrated in Figures 17 and following, the slider 50 is provided on the ends of its lateral flanges 52, 54, returns 53, 55 respectively directed towards the inside of the bag. These returns 53, 55 are positioned to be located beyond the sealing means 100. On the one hand these returns 53, 55 participate in sealing the bag. On the other hand these returns 53, 55 participate in maintaining the cursor 50 on the bags to prohibit an inadvertent withdrawal of the cursor. As can be seen in FIG. 17, these returns 53, 55 urge the sheets 16, 18 closer together, beyond the sealing means 100.

It will also be noted that according to the embodiments illustrated in FIGS. 17 and following, preferably, the portions of support films 16, 18 situated opposite closure profiles 20, 22 and sealing means 100 have a greater thickness at the thickness of rest of the film composing the bag. This extra thickness of the support films 16, 18 to the right of the slider 50 keeps the means 100 in their sealing position when the bag is in the closed position. Such a localized excess thickness of the films 16, 18 may be obtained in the form of an excess thickness formed during the extrusion of the film or may result from the attachment of support webs of the closure profiles 20, 22 or means 100, as indicated above. .

FIG. 18 illustrates another variant embodiment in which the two elements 104, 106 integral respectively with the inner surface of the sheets 16, 18 are provided at their apices with a respective wing 1040, 1060 orthogonal to said elements. Thus said wings 1040, 1060 extend generally parallel to the sheets 16, 18. The elements 104, 106 are supported at their apex by means of these wings 1040, 1060.

According to the embodiment of Figure 18, said wings 1040, 1060 are directed towards the inside of the bag. Alternatively one can predict that the wings 1040, 1060 are instead directed towards the outside of the bag. According to yet another variant, one can provide such wings 1040, 1060 on the top of the elements 104, 106 both inwardly and outwardly of the bag. In this case, the elements 104, 106 provided with wings 1040, 1060 have the general shape of a T.

FIG. 19 illustrates an alternative embodiment of FIG. 17 in which at least one of the two juxtaposed elements 104, 106 is provided at its top with an orthogonal wing 1060. This is intended to rest against the inner face of the opposite sheet 16 to complete the seal. According to FIG. 19, there is shown such a wing 1060 on only one of the elements 106. In a variant, however, it is possible to provide such an additional wing intended to rest against the inner face of the opposite sheet, on the top of the two elements 104. , 106.

FIG. 20 shows another variant embodiment of FIG. 17 in which the two juxtaposed elements 104, 106 are provided at their apices with a rounded protrusion 1042, 1062. This is intended to rest against the internal face of sheet 16, 18opposite to complete the seal. According to FIG. 20, such an outgrowth is provided on the two elements 104, 106. As a variant, such an outgrowth 1042, 1062 can be provided on a single element 104, 106. According to FIG. 20, these excrescences have a circular cross section. and are symmetrical with respect to the median plane of the elements 104, 106. However, the invention is not limited to this particular geometry.

FIG. 21 illustrates an alternative embodiment of FIG. 18 in which the slider 50 is further provided at the ends of each of the returns 53, 55 with an additional wing 530, 550 directed towards the base 56 of the cursor 50, that is to say towards the outside of the bag. These wings 530, 550 are thus oriented generally parallel to the lateral wings 52, 54 of the slider 50. These additional wings 530, 550 are designed to assume a position in the volume defined between the sheets 16, 18 and 1040, 1060 of the means. Sealing 100. It is understood from the examination of FIG. 21 that these wings 530, 550 provide a corrugation on the sheets 16, 18 that can further enhance the tightness of the bags obtained.

According to the embodiments previously described, the slider 50 has a symmetry with respect to a longitudinal plane. Thus, according to FIGS. 17 to 19, each of the flanks 52, 54 is provided with a return 53, 55.

On the other hand, according to the variant illustrated in FIG. 22, the slider has an asymmetry in the sense that only one of the flanks 52 is provided with such a return 53 directed towards the inside of the bag.

FIG. 23 illustrates an alternative embodiment of FIG. 22 in which this return 53 is provided on its inner surface with a boss 532 directed towards the base 56 to urge the two juxtaposed elements 104, 106 supported by through their adjacent flanks 103, 105. For this the boss 532 exerts on the element 104 a bias directed towards the base 56.

FIG. 24 shows another variant embodiment in which the support film portions 16, 18 carrying the closing profiles 20, 22 and the sealing means 100 are not situated in the direct extension of the sheets making up the body. of the bag, but are shifted towards the outside of the bag at the level of respective recesses 1600, 1800. These recesses 1600, 1800 can be obtained by extrusion during the manufacture of the film or be obtained later by folding the film. FIG. 24 shows that such recesses 1600, 1800 facilitate the juxtaposition of the sheets 16, 18 at the exit of the slider 50, although the sheets 16, 18 are necessarily separated, within the slider because of the presence of closure profiles 20, 22 and means 100.

It will also be noted from the examination of FIG. 24 that, if appropriate, one of the recesses 1800 may itself be provided with an extension 1802 directed towards the opposite support sheet 16. This extension 1802 is designed to rest against the recess 1600 opposite to further strengthen the tightness of the bags obtained.

FIG. 25 illustrates an alternative embodiment in which a projection 530 or return towards the inside of the cursor on the single return 53 is provided on the one hand and on the other hand an element 106 projecting from the sheet 18 Thus, as can be seen in FIG. 25, the boss 530 imposes a curvature or labyrinth path to the second sheet 16 at the exit of the slider 50, again making it possible to reinforce the tightness of the bag obtained.

FIG. 26 illustrates an alternative embodiment of FIG. 17 in which at least one of the two elements 104 or 106 has an increasing thickness in the direction of its vertex or has an inclined flank so that it exerts an force on the other element 106 or 104 juxtaposed, in the closed position of the bag.

FIGS. 27 and following illustrate variant embodiments according to which the sealing means 100 are formed essentially of flexible and elastic structures, to be deformable when the bag is closed, whereas according to the representations given in FIGS. at 26, the means 100 are essentially rigid.

FIG. 27 thus illustrates a variant embodiment according to which the sealing means 100 comprise a curved, flexible and elastic lip 130 integral with the sheet 18 carrying the female closure profile 22.

As a variant, such a flexible and elastic lip 130 could be integral with the sheet 16 which carries the male closure profile 20.

According to Figure 27 the lip 130 is formed of a cylinder sector whose central angle is greater than 180 °. According to Figure 27, the concavity of the lip 130 is directed towards the inside of the bag. Alternatively, however, it could be provided that the concavity of the lip 130 is directed towards the outside of the bag.

As can be seen in FIG. 27, in the closed position of the bag, the top of the lip 130 comes to rest against the opposite support sheet 16. For this, as can be seen in FIG. 28, in the open state of the bag, said lip 130 extends beyond the associated closure profile 22. With this arrangement it is ensured that in the closed state of the bag, said lip 130 exerts pressure on the opposite sheet 16.

FIG. 29 illustrates an alternative embodiment of FIG. 27 in which the location of the lip 130 and the geometry of this lip 130 are such that said lip 130, when it rests on the opposite sheet 16, receives a reaction. which urges it itself in support against one of the closure profiles, in this case the female closure profile 22.

FIG. 30 illustrates another embodiment in which such a biasing of the lip 130 bearing against the female closure element 22 is reinforced by the presence on the inner surface of the flanks 52, 54 of the boss slider 50. 520, 540. In this case according to the representation given in FIG. 30, these bosses 520, 540 have a triangular general profile. However, these bosses 520, 540 are not limited to this geometry and can be the subject of many variants.

Note that in Figure 30 the central sole of the slider 50 which controls the engagement, respectively the separation of the closure profiles 20, 22 is referenced 57.

FIG. 31 shows a side view of a bag thus equipped. 26 a slider 50 having such stressing bosses 520, 540, as well as the closing profiles 20, 22 and the sealing means 100. It will be noted on examining FIG. preferably the bosses 520, 540 extend only over a portion of the length of the slider 50 and also converge towards the upper base 56 of the slider 50 towards the end of the slider 50 located on the opening side of the bag. With this arrangement, the bosses 520, 540 urge the lip 130 bearing against the closure profile 22, near the opening zone of the bag.

Similarly, the returns 53, 55 provided on the wings 52, 54 of the slider 50 can converge towards the base 56 towards the end of the slider 50 located on the side of the opening of the bag, to improve the tightness of the bag. at this level.

FIG. 32 illustrates another variant embodiment in which each of the two sheets 16, 18 is provided on its inner surface with an elastic lip 130 in the cylinder sector. These two lips 130 are thus supported by their top when closing the bag.

For this again, at rest, that is to say in the open position, at least one of the two lips 130 preferably extends beyond the associated closure profile, as shown schematically in FIG. 33.

The slider 50 used in the context of the variant embodiment of FIG. 32 may also include upwardly-pressing bosses 520, 540, as illustrated in FIG. 31, for biasing these elastic lips 130 against the closure profiles 20, 22, in the closed position of the bag.

FIG. 34 illustrates another variant embodiment in which each of the two support films 16, 18 is provided with an elastic lip 130, but however these are positioned not to bear against their top, but to be side juxtaposed as seen in Figure 34. For this the two lips 130 each formed of a cylinder sector having an angle at the center greater than 180 ° have their concavity directed respectively inwardly and outwardly of the bag.

We will now describe the embodiments shown in Figures 35 to 44 attached.

As indicated above, according to these variants, the bag comprises on its mouth 12, means 150 located opposite said additional sealing means 100, with respect to the closure profiles 20, 22, and these means 150. are adapted to define a support between the opposite internal faces of the walls of the bag. In addition, on the slider 50, means are provided capable of urging the walls of the bag inwards into an area of these walls between the additional sealing means 100 and the bearing means 150. that said additional means 100 are urged in a sealing position by the slider 50. Preferably this bias is made to the right of the closure profiles 20 and 22.

Thus, preferably, as can be seen in the appended figures, the additional sealing means 100 are located on the inside of the closure profiles 20, 22, while the means 150 defining the support are located on the outside of the profiles. closure 20, 22.

This arrangement comprising means 150 associated with means for biasing the sealing means 100 by the slider 50 can be applied to all of the previously described embodiments. It is therefore not limited to the embodiments of Figures 30 to 39. In particular this provision applies to any type of sealing means 100, to any type of closure profiles 20, 22 and all cursor variants 50 or sachet equipped with an antiviolating veil, etc ...

FIG. 35 illustrates a variant according to which the additional sealing means 100 are formed of two flexible and elastic lips 170, 172 which are symmetrical and integral respectively with the inner face of the walls 16 and 18, and directed inwards. and the bottom of the bag. As a variant, these lips 170, 172 may be directed towards the inside of the slider 50 (in particular, for example, for vacuum bags). As indicated above, the arrangement with support means 150 applies to all types of sealing means 100 and is not limited to the means 100 of FIG. 35. It may especially apply to lips 170, 172 symmetrical.

Similarly according to Figure 35, the closure profiles 20, 22 are of the male / female type. However, the invention can be applied to any other type of closure profile, in particular hook profiles.

According to Figure 35, the support means 150 are formed of two symmetrical elements 152, 154, integral respectively the inner faces of the walls 16, 18, at the mouth of the bag. More specifically according to Figure 35, each of these elements 152, 154 has a rectangular cross section and extends towards the median plane of the bag at which, these elements are in mutual support, in the closed position of the bag. Thus, these elements 152 and 154 extend generally perpendicularly to this median plane.

It will be noted that according to FIG. 35, the means 100, the profiles 20, 22 and the means 150 are made of material, possibly materials, preferably extruded, with the walls 16, 18. More precisely still note that the sections of these walls between the sealing means 100 and the support means 150 are thicker than the sheets 16, 18 making up the rest and most of the bags. Thus the aforementioned sections have a certain rigidity between the means 100 and the means 150.

Those skilled in the art will understand that by virtue of the aforementioned characteristics, when the elements 152, 154 are in abutment and the slider 50 exerts a stress on the aforementioned sections of the walls 16, 18, situated between the means 100 and 150, the sealing means 100 are solicited themselves in their position of contact and maximum sealing.

FIG. 36 illustrates the biasing means provided on the slider 50, in the form of bosses 520, 540 provided on the inner surface of the wings 52, 54, to the right of the closure profiles 20, 22. bosses formed cylindrical caps, but the invention is not limited to this particular geometry.

FIG. 36 denotes F1 the force exerted by the slider 50 on the mouth sections of the walls of the bag, F2 the reaction due to the means 150 and F3 the force then exerted on the sealing means 100.

Note also that according to Figure 36 the aforementioned sections define at the mouth of the bag a cage of rectangular cross section which projects relative to the main walls 16 and 18 of the bag. In other words, the main walls of the bag are not coplanar with the external surfaces of these sections, but are set back inwards, with respect to these, by a value "d". It is thus defined on the walls 16 and 18 of the bag a recess that serves to support the returns 53 and 55 provided on the wings 52 and 54 of the slider 50, to prevent inadvertent withdrawal thereof.

FIG. 37 illustrates a variant according to which such a step is eliminated. Thus, according to FIG. 37, on the contrary, the main walls of the bag are coplanar, at rest, from the external surfaces of the sections situated between the means 100 and 150. However, such a variant can also cooperate with a slider 50 equipped with returns 53, 55 on its wings 52, 54 thanks to the permitted deformation of the sheets 16, 18.

According to the variant illustrated in Figure 38, the aforementioned sections between the means 100 and 150 define at the mouth of the bag not a cage of rectangular cross section, but a generally rounded cage.

According to FIGS. 35 to 38 previously described, the bearing elements 152, 154 are symmetrical and contact each other in the median plane of the bag. Alternatively, however, these elements 152, 154 can be asymmetrical and thus contact outside the median plane. There is thus illustrated in FIG. 39, a variant according to which only the wall 18 is provided with a bearing element 154 projecting on its internal face. This element 154 is adapted to rest on the inner face of the opposite wall 16.

According to FIGS. 35 to 39 previously described, the sealing means 100, the closure profiles 20, 22 and the support means 150 are made of material, possibly of materials, preferably extruded, on the walls 16, 18. In a variant, these various means may be on respective attached support webs, for example thermally welded or bonded to the inner faces of the sheets. 16, 18. It may be respective and separate support webs for each of the means 100, profiles 20, 22 and means 150, or the support sails common to several of these means. Thus, for example, FIG. 40 illustrates an alternative embodiment in which the means 100, the closure profiles 20, 22 and the support means 150 are carried by two respective webs, one on the inner face of the sheet 16, and brought the other on the inner face of the sheet 18.

FIG. 41 illustrates a variant embodiment according to which the biasing means are formed not of integral bosses of the internal face of the flanges of the slider, but of bosses projecting from the outside face of the sections of wall situated between the flanges. means 100 and 150, preferably to the right of closure profiles 20, 22. According to yet another variant can be provided bosses both on the slider and on the walls of the bag.

FIG. 42 illustrates another variant embodiment in which the ends facing the elements 152 and 154 forming support means are enlarged, to guarantee that these elements can be supported and to avoid these elements being displaced by offset. adjacent, in which case the lever expected to exercise the bias on the means 100 would not be obtained. According to Figure 42 the adjacent ends of the elements 152 and 154 have a generally triangular cross section whose base is located in the contact plane. However, the invention is not limited to this particular provision.

FIG. 43 illustrates a variant according to which the slider 50 is equipped on the inner face of its wings 52, 54 with projecting structures 522, 542 of complementary cross section with grooves 13 formed in the aforementioned bosses 15, the structures 522 and 542 being engaged in these grooves 13. More precisely still the structures 522, 542 are flared, while the grooves 13 have convergent edges. Thanks to this arrangement, it avoids an unwanted withdrawal of the slider 50.

FIG. 44 illustrates another variant embodiment in which forms-complementary means are thus defined between the slider 50 and the walls of the bag, at the level of the returns 53, 55 formed on wings 52, 54, in the form of elements 530, 550 as previously described.

If necessary, the elements making up the sealing means 100 may be coextruded with the bag and / or the closure strips, into a material that is more flexible than the material forming the latter. For example, it is possible to coextrude the lips 170, 172 into an ethylene copolymer or a synthetic elastomer.

As has been indicated above, of course, the present invention is not limited to the particular embodiments which have just been described, but extends to all variants that are in keeping with its spirit.

By "sealing" is meant in the context of the present invention that the means 100 are adapted (according to their geometry and / or their support force) or to provide a complete barrier prohibiting any penetration from the outside to the inside of the bag and any leakage from the inside to the outside of the bag, either to ensure at least one barrier in one direction, that is to say to prohibit penetration from the outside to the inside of the bag, or to prohibit a leak from the inside to the outside of the bag.

Note also that the return means 53, 55 and the structures such as 522 and 542, provided on the bag and which participate in maintaining the cursor 50 on the bag, are generally not alone to ensure this maintenance, but for example complete in this function flared means provided on the central sole of the slider 50.

Those skilled in the art will also understand that in the context of the embodiments illustrated in FIGS. 35 to 44, the sealing means 100 may not be placed facing the flanks 52, 54 of the slider, but outside of it. In other words, in this case, the end of the slider is located between these means 100 and the closing profiles 20, 22.

Claims (83)

1. A bag comprising two generally parallel sheets (16, 18) forming the main walls of the bag, complementary closure strips (20, 22) fixed to respective ones of said sheets (16, 18) in the vicinity of the mouth of the bag, and a cursor (50) having two side flanges (52, 54) interconnected by a web (56), the flanges being placed on the outsides of the sheets (16, 18) at the mouth of the bag and co-operating with a central elongate tongue (59) to define two converging passages (590, 592) for the complementary closure strips (20, 22), the side flanges (52, 54) being provided in the vicinity of their free edges remote from the web (56) with urging means (520, 540; 100) for urging the sheets (16, 18) of the bag towards each other, said means occupying the entire longitudinal extent of the tongue (59), the bag being characterized by the facts that the tongue (59) is interrupted so as to be set back from the longitudinal end of the cursor (50), at the wider end of the cursor corresponding to the diverging ends of the passages (590, 592), and that the urging means are constituted by ribs (520, 540) projecting inwards from the cursor (50) from the edges of its flanges (52, 54) remote from the web (56) or from portions of the height of the inside surfaces of said flanges (52, 54) extending between the free edges of the flanges (52, 54) and the web (56), the ribs (520, 540) being situated beyond the tongue (59), and the ribs (520, 540) extending over the entire length of the cursor (50) while the tongue (59) is interrupted in the vicinity of its broader end at a distance ( 1 ₁) from the end of the cursor (50) lying in the range 1 mm to 10 mm, so as to ensure that the bag is leakproof when it is in its closed position.
2. A bag according to claim 1, characterized by the fact that the tongue (59) is also interrupted close to its narrower end, adjacent to the converging ends of the passages (590, 592), at a distance ( l ₂) from the end of the cursor (50).
3. A bag according to claim 1 or 2, characterized by the fact that the width ( l ₆) of the empty space defined between the tips of the ribs (520, 540) is substantially equal to the sum of the thicknesses of the sheets (16, 18) at the mouth of the bag.
4. A bag according to any one of claims 1 to 3, characterized by the fact that the cursor has two ribs (520, 540) that are symmetrical and of the same height, one on each of its flanges (52, 54).
5. A bag according to any one of claims 1 to 3, characterized by the fact that the cursor (50) has ribs (520, 540) that are asymmetrical, or have a single rib on one of her flanges (52, 54) of the cursor (50).
6. A bag according to any one of claims 1 to 5, characterized by the fact that the distance ( l ₂) between the narrow end of the tongue (59) and the end of the cursor lies in the range 0.5 mm to 10 mm.
7. A bag according to any one of claims 1 to 6, characterized by the fact that the height ( l ₃) of the tongue (59) lies in the range 2 mm to 7 mm.
8. A bag according to any one of claims 1 to 7, characterized by the fact that the distance ( l ₄) between the tip of the tongue (59) and the urging means (520, 540) lies in the range 5 mm to 15 mm.
9. A bag according to any one of claims 1 to 8, characterized by the fact that the width ( l ₅) of the tongue (59) at its broad end lies in the range 0.3 mm to 2 mm.
10. A bag according to any one of claims 1 to 9, characterized by the fact that the width ( l ₆) of the opening provided between the urging means (520, 540) lies in the range 50 µm to 2.5 mm.
11. A bag according to any one of claims 1 to 10, characterized by the fact that the ratio ( l ₁/ l ₅) of the distance ( l ₁) between the broad end of the tongue (59) and the end of the cursor over the thickness ( l ₅) of the tongue (59) at its broad end lies in the range 0.5 to 30.
12. A bag according to any one of claims 1 to 11, characterized by the fact that the ratio ( l ₂ / l ₅ ) of the distance ( 1 ₂) between the narrow end of the tongue (59) and the end of the cursor over the thickness ( 1 ₅) of the tongue (59) at its broad end lies in the range 2.5 to 30.
13. A bag according to any one of claims 1 to 12, characterized by the fact that the ratio ( 1 ₁/ 1 ₃) of the distance ( 1 ₁) between the broad end of the tongue (59) and the end of the cursor over the height ( l ₃) of the tongue (59) lies in the range 0.5 to 5.
14. A bag according to any one of claims 1 to 13, characterized by the fact that the ratio ( l ₂/ l ₃) of the distance ( l ₂) between the narrow end of the tongue (59) and the end of the cursor over the height ( l ₃) of the tongue (59) lies in the range 0.1 to 5.
15. A bag according to any one of claims 1 to 14, characterized by the fact that the ratio ( l / l ₄) of the distance ( l ₁) between the broad end of the tongue (59) and the end of the cursor over the thickness ( l ₄) between the tip of the tongue (59) and the urging means (520, 540) lies in the range 0.05 to 2.
16. A bag according to any one of claims 1 to 15, characterized by the fact that the ratio ( l ₂/ l ₄) of the distance ( l ₂) between the narrow end of the tongue (59) and the end of the cursor over the thickness ( l ₄) between the tip of the tongue (59) and the urging means (520, 540) lies in the range 0.05 to 2.
17. A bag according to any one of claims 1 to 16, characterized by the fact that it further comprises, parallel to the closure strips (20, 22), between said sheets (16, 18) and at the mouth (12) of the bag, additional means in relief (100) designed to provide leakproofing by forming a barrier between the sheets (16, 18) when the bag is in its closed position, said additional leakproofing means (100) being adapted to be urged towards their leakproofing position by the cursor (50) when the cursor is moved towards its bag-closure position.
18. A bag according to claim 17, characterized by the fact that the additional leakproofing means providing leakproofing (100) are constituted by at least one bead (102; 104, 106) secured to the inside surface of a sheet (16) of the bag.
19. A bag according to claim 17 or 18, characterized by the fact that the additional leakproofing means providing leakproofing (100) are made up of two beads (104, 106) secured respectively to the inside surfaces of the two sheets (16, 18) of the bag.
20. A bag according to claim 17, characterized by the fact that the additional leakproofing means providing leakproofing (100) are constituted by complementary male/female elements (110, 112) respectively secured to the inside surfaces of the two sheets (16, 18) of the bag.
21. A bag according to claim 20, characterized by the fact that the male element (110) is substantially triangular in section.
22. A bag according to claim 20 or 21, characterized by the fact that the female element (112) has two lips (1120 and 1122) that are asymmetrical.
23. A bag according to any one of claims 20 to 22, characterized by the fact that the lip (1120) of the female element (112) situated closer to the inside of the bag relative to the male element (110) is longer and more flexible than the second lip (1122) thereof situated towards the outside of the bag.
24. A bag according to any one of claims 17 to 23, characterized by the fact that the additional leakproofing means providing leakproofing (100) are disposed on the inside of the closure strips (20, 22).
25. A bag according to any one of claims 17 to 24, characterized by the fact that the additional leakproofing means providing leakproofing (100) extend over the entire length of the bag.
26. A bag according to any one of claims 17 to 25, characterized by the fact that the shapes of the strips (20, 22), of the additional means (100), and of the cursor (50) are such that the flanks (52, 54) of the cursor (50) impart transverse play to the means (100) smaller than that which is tolerated for the closure strips (20, 22).
27. A bag according to any one of claims 17 to 26, characterized by the fact that the inside surfaces of the flanks (52, 54) of the cursor (50) are parallel, and the thickness (L₁) of the leakproofing means (100) is greater than the thickness (L₂) defined by the closure strips (20, 22) when they are mutually engaged.
28. A bag according to any one of claims 17 to 27, characterized by the fact that the cursor (50) has beads (520, 540) on the inside surfaces of its flanks (52, 54), the beads being placed in register with the leakproofing means (100) to guarantee that said means are urged towards a leakproofing position when the bag is closed.
29. A bag according to any one of claims 17 to 28, characterized by the fact that the walls of the bag have beads faced in register with the leakproofing means (100) and in register with the flanks of the cursor (50) to guarantee that the leakproofing means (100) are urged into a leakproofing position when the bag is closed.
30. A bag according to any one of claims 17 to 29, characterized by the fact that it comprises both grooves (160, 180) opening out to the outside surface of the bag, respectively in register with the leakproofing means (100), and also ribs (522 and 542) projecting from the inside surfaces of the flanks (52 and 54) of the cursor (50), which ribs (522 and 542) are adapted to penetrate respectively into said grooves (160 and 180).
31. A bag according to any one of claims 17 to 30, characterized by the fact that it includes means (19, 24) forming a tamperproofing web at the mouth (12) to show whether or not the bag has been opened.
32. A bag according to claim 31, characterized by the fact that the tamperproofing web (24) forms a bellows that is folded towards the inside of the bag at the mouth (12) and in continuity with the support webs (121, 21 and 123, 23) for the closure strips or the additional leakproofing means.
33. A bag according to claim 31, characterized by the fact that the tamperproofing web (19) is formed by a bellows folded towards the inside of the bag at the mouth (12) in continuity with the film constituting the bag.
34. A bag according to any one of claims 17 to 33, characterized by the fact that the bag (10) is made from a single film that is folded over onto itself with the fold constituting the bottom (14) of the bag.
35. A bag according to any one of claims 17 to 33, characterized by the fact that the bag (10) is formed from a single film that is folded over onto itself with the fold being at the mouth (12) of the bag.
36. A bag according to any one of claims 17 to 33, characterized by the fact that the bag (10) is made from two sheets (16, 18) that are initially separate and that are superposed during manufacture.
37. A bag according to any one of claims 17 to 36, characterized by the fact that the complementary closure strips (20, 22) and/or the additional leakproofing means (100) are extruded together with the sheets (16, 18) constituting the bag.
38. A bag according to any one of claims 17 to 36, characterized by the fact that the complementary closure strips (20, 22) and/or the additional leakproofing means (100) are initially formed on respective support webs (21, 23; 121, 123) that are fitted to the sheets (16, 18) at the mouth (12) of the bag.
39. A bag according to any one of claims 17 to 36 and 38, characterized by the fact that the complementary closure strips (20, 22) and the additional leakproofing means (100) are initially formed on common support webs (21, 23; 121, 123) that are secured to the sheets (16, 18) at the mouth (12) of the bag.
40. A bag according to any one of claims 17 to 39, characterized by the fact that the closure strips (20, 22) are adapted to provide transverse urging (P) automatically on the leakproofing means (100) when the bag is closed.
41. A bag according to any one of claims 17 to 40, characterized by the fact that the complementary closure strips (20, 22) are of the male/female type and they comprise at least one asymmetrical male or female strip.
42. A bag according to claim 41, characterized by the fact that the height occupied (L₃) by the element (220) defining the inner lip of the female strip (22) is less than the height occupied (L₄) by the element (222) defining the outer lip of the female strip (22).
43. A bag according to any one of claims 17 to 40, characterized by the fact that the complementary closure strips (20, 22) are of the hook type and possess at least two pairs of complementary hooks defining widths in the assembled position that are different from one pair of hooks to the other.
44. A bag according to claim 43, characterized by the fact that the two complementary hooks (C1, C2) situated towards the inside of the bag define, in the assembled position, a width (L₅) between the inside faces of the sheets (16, 18) that is smaller than the width (L₆) taken between the same faces of the sheets (16, 18) in the vicinity of the pair of complementary hooks (C3, C4) situated towards the outside of the bag.
45. A bag according to any one of claims 17 to 44, characterized by the fact that the additional leakproofing means for providing leakproofing (100) are made up of two elements (104, 106) respectively secured to the inside surfaces of the two sheets (16, 18) of the bag and designed to bear against each other via their tips.
46. A bag according to any one of claims 17 to 44, characterized by the fact that the additional leakproofing means providing leakproofing (100) are made up of two elements (104, 106) secured respectively to the inside surfaces of the two sheets (16, 18) of the bag and designed to be juxtaposed so as to bear against each other via adjacent facing flanks (103, 105) that are generally perpendicular to the sheets (16 and 18).
47. A bag according to any one of claims 17 to 44, characterized by the fact that the cursor (50) is provided on the ends of at least one of its side flanges (52, 54) with rims (53, 55) directed towards the inside of the bag and positioned so as to be situated beyond the leakproofing means (100).
48. A bag according to claim 47, characterized by the fact that the cursor (50) is also provided at the end of said rim (53, 55) with an additional flange (530, 550) directed towards the web (56) of the cursor (50), i.e. towards the outside of the bag.
49. A bag according to any one of claims 17 to 48, characterized by the fact that the portions of the support films (16, 18) situated facing the closure strips (20, 22) and the leakproofing means (100) are of thickness greater than the thickness of the remainder of the film constituting the bag.
50. A bag according to claim 49, characterized by the fact that the local extra thickness of the films (16, 18) is obtained in the form of extra thickness formed during extrusion of the film.
51. A bag according to claim 49, characterized by the fact that the local extra thickness of the films (16, 18) results from support webs for the closure strips (20, 22) or for the leakproofing means (100) being fixed thereto.
52. A bag according to claim 19 or 45, characterized by the fact that the two elements (104, 106) secured respectively to the inside surfaces of the sheets (16, 18) are provided at their tips with at least one respective flange (1040, 1060) orthogonal to said elements.
53. A bag according to claim 19 or 46, characterized by the fact that at least one of the two elements (104, 106) provided on the support sheets is provided at its tip with an orthogonal flange (1060) to rest against the inside face of the opposite sheet (16).
54. A bag according to claim 19 or 46, characterized by the fact that at least one of the two elements (104, 106) provided on the support films is fitted at its tip with a rounded bulge (1042, 1062).
55. A bag according to claim 48, characterized by the fact that the cursor (50) is also provided at the end of said rim (53, 55) with a bead (532) directed towards its web (56) to urge the two juxtaposed elements (104, 106) to press against each other via their adjacent flanks (103, 105).
56. A bag according to any one of claims 17 to 55, characterized by the fact that the portions of the support films (16, 18) carrying the closure strips (20, 22) and the leakproofing means (100) are not situated directly in line with the sheets constituting the body of the bag, but are offset towards the outside of the bag via respective setbacks (1600, 1800).
57. A bag according to claim 56, characterized by the fact that one of the offsets (1800) is itself provided with an extension (1802) directed towards the opposite support sheet (16).
58. A bag according to claim 19 or 46, characterized by the fact that at least one of the two elements (104 or 106) presents thickness that increases towards its tip or possesses a sloping flank so that it exerts a force on the juxtaposed other element (106 or 104) when the bag is in its closed position.
59. A bag according to any one of claims 17 to 58, characterized by the fact that the leakproofing means (100) comprise structures that are flexible and resilient so as to be deformable when the bag is closed.
60. A bag according to any one of claims 17 to 59, characterized by the fact that the leakproofing means (100) comprise at least one curved, flexible, and resilient lip (130) secured to the sheet (18) carrying one of the closure strips (22).
61. A bag according to claim 60, characterized by the fact that the lip (130) is formed by a sector of a cylinder whose angle at the center is greater than 180°.
62. A bag according to claim 60 or 61, characterized by the fact that in the open state of the bag, said lip (130) extends beyond the associated closure strip (22) so that in the closed state of the bag, said lip (130) exerts pressure on the opposite sheet (16).
63. A bag according to any one of claims 60 to 62, characterized by the fact that the position of the lip (130) and the shape of said lip (130) are such that said lip (130), when resting against the opposite sheet (16) receives reaction which urges it itself to bear against one of the closure strips.
64. A bag according to claim 63, characterized by the fact that the urging of the lip (130) to bear against the female closure element (22) is reinforced by the presence of beads (520, 540) on the inside surfaces of the flanks (52, 54) of the cursor (50).
65. A bag according to claim 64, characterized by the fact that the beads (520, 540) converge towards the top web (56) of the cursor (50) on going towards the end of the cursor (50) which is situated beside the opening of the bag.
66. A bag according to any one of claims 17 to 65, characterized by the fact that each of the two sheets (16, 18) is provided on its inside surface with a resilient lip (130) in the form of a sector of a cylinder, which lips are designed to bear against each other via their tips when the bag is closed.
67. A bag according to any one of claims 17 to 65, characterized by the fact that each of the two sheets (16, 18) is provided on its inside surface with a resilient lip (130) in the form of a cylindrical sector, the lips being designed to be juxtaposed laterally.
68. A bag according to any one of claims 17 to 67, characterized by the fact that, in the vicinity of its mouth (12) it includes means (150) situated on the side of the closure strips (20, 22) opposite from the side on which said additional leakproofing means (100) are situated, and adapted to define thrust between opposing inside faces of the walls of the bag, and means (520, 540) are provided on the cursor (50) to urge the walls of the bag inwards in a zone of said walls lying between the additional leakproofing means (100) and the thrust means (150).
69. A bag according to claim 68, characterized by the fact that urging takes place in register with the closure strips (20, 22).
70. A bag according to claim 68 or 69, characterized by the fact that the additional leakproofing means (100) are situated inside the closure strips (20, 22) while the thrust defining means (150) are situated on the outside of the closure strips (20, 22).
71. A bag according to any one of claims 68 to 70, characterized by the fact that the additional leakproofing means (100) are formed by two flexible and resilient lips (170, 172).
72. A bag according to any one of claims 68 to 71, characterized by the fact that the thrust means (150) are formed by two elements (152, 154) secured respectively to the inside faces of the walls (16, 18) at the mouth of the bag.
73. A bag according to claim 72, characterized by the fact that said elements (152, 154) thrust against each other in a midplane of the bag when the bag is in its closed position.
74. A bag according to claim 72, characterized by the fact that said elements (152, 154) thrust against each other away from the midplane of the bag when the bag is in its closed position.
75. A bag according to any one of claims 68 to 74, characterized by the fact that the thrust means (150) are made by being extruded with the walls (16, 18) of the bag.
76. A bag according to any one of claims 68 to 74, characterized by the fact that the thrust means (150) are made by being extruded onto webs added to the walls (16, 18) of the bag.
77. A bag according to any one of claims 68 to 76, characterized by the fact that the wall segments lying between the leakproofing means (100) and the thrust means (150) are thicker than the sheets (16, 18) constituting the remainder and the major portion of the bags.
78. A bag according to any one of claims 68 to 79, characterized by the fact that the urging means comprise beads (520, 540) on the inside surfaces of the flanges (52, 54) of the cursor (50).
79. A bag according to any one of claims 68 to 78, characterized by the fact that the urging means comprise beads on the walls of the bag.
80. A bag according to claim 78 or 79, characterized by the fact that the beads (520, 540) are provided in register with the closure strips (20, 22).
81. A bag according to any one of claims 68 to 80, characterized by the fact that the facing ends of the elements (152, 154) forming the thrust means are enlarged, e.g. having a right cross-section that is generally triangular.
82. A bag according to any one of claims 17 to 81, characterized by the fact that the elements making up the leakproofing means (100) are coextruded with the bag and/or the closure strips out of a material that is more flexible than the material forming said bag or strips, e.g. a copolymer of ethylene or a synthetic elastomer.
83. A bag according to any one of claims 17 to 82, characterized by the fact that said additional means in relief are placed in register with the flanks of the cursor.

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