WO1999036325A1

WO1999036325A1 - Bag with complementary formed closing sections actuated by a slide and method, apparatus and film for producing same

Info

Publication number: WO1999036325A1
Application number: PCT/FR1999/000070
Authority: WO
Inventors: Henri Georges Bois
Original assignee: Flexico-France
Priority date: 1998-01-16
Filing date: 1999-01-15
Publication date: 1999-07-22
Also published as: ZA99309B; FR2773679A1; FR2773679B1; AU2058599A

Abstract

The invention relates to a bag having complementary formed closing sections (20, 22) and a slide (50) for moving the formed sections (20, 22) into closed and open positions, characterized in that it also comprises areas of increased thickness (30, 32) made by extrusion of the bag film facing the formed closing sections (30, 32).

Description

BAG COMPRISING ADDITIONAL CLOSING CLOSURE PROFILES, AS WELL AS PROCESS, MACHINE AND FILM FOR THE PRODUCTION THEREOF

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

Bags of this type have given rise to an abundant literature. On this point, reference may be made, for example, to documents EP-A-0051010. EP-A-0102301 and EP-A-0479661. The present invention now aims to improve the performance of known slider bags.

A first aim of the present invention is in particular to propose new sachets making it possible to limit the risk of untimely withdrawal of the cursor, in particular in order to limit the risk of ingestion by young children.

Another object of the present invention is to propose new sachets allowing a high productivity rate in automatic.

Another object of the present invention is in particular to provide slider bags allowing, on the one hand a good seal and on the other hand a use in the field of freezing.

The aforementioned aims are achieved in the context of the present invention by means of a bag comprising complementary closure profiles and a slider for actuating the profiles at closure and at opening, characterized in that it also comprises extra thicknesses extrusions coming onto the film making up the bag opposite the closure profiles, which extra thicknesses have a thickness of between 0.5 and 3 mm at the level of the recess cooperating with the slider.

According to another advantageous characteristic of the present invention, the aforementioned extra thicknesses protrude from the outside surface of the bag. According to another advantageous characteristic of the present invention, the closure profiles themselves have come from extrusion on the film making up the bag.

The present invention also relates to a method, a machine and a film for producing the above-mentioned sachets.

Other characteristics, objects and advantages of the present invention will appear on reading the detailed description which follows, and with reference to the appended drawings, given by way of nonlimiting examples and in which: - Figure 1 shows a view schematic sectional view of a sachet in accordance with a first embodiment of the present invention,

FIG. 2 illustrates a first alternative embodiment of this first embodiment,

FIG. 3 represents a schematic sectional view of a sachet according to another variant of this first embodiment according to the invention,

FIG. 4 represents a schematic sectional view of a sachet in accordance with a second embodiment of the present invention,

FIG. 5 represents a variant of this second embodiment, FIG. 6 schematically illustrates a sectional view of a film intended for this second embodiment, during an extrusion step,

FIGS. 7a and 7b show diagrammatically an installation in accordance with the present invention for the production of sachets,

FIG. 8 schematically illustrates a sectional view of a film, during an extrusion step, intended for a variant of the present invention,

FIG. 9 schematically illustrates a sectional view of a sachet according to another alternative embodiment of the present invention,

FIG. 10 represents another alternative embodiment in accordance with the present invention, FIG. 11 represents another alternative embodiment in accordance with the present invention,

FIG. 12 shows another variant embodiment in accordance with the present invention, and - Figure 13 shows another alternative embodiment according to the present invention.

There is shown diagrammatically in FIG. 1 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 connected together at the bottom 14 (by folding, the two sheets 16, 18 being joined together as shown in FIG. 1, or by welding or gluing, the two sheets 16, 18 being initially separated and superimposed during manufacturing), as well as at the two lateral edges perpendicular to the bottom 14 (the connection at the lateral edges is preferably ensured by welding or gluing).

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

These complementary closure sections 20, 22 can be the subject of numerous embodiments. The invention is not limited to the precise embodiment illustrated in the attached FIG. 1.

In particular, the invention applies to closure profiles of the male and female type respectively as is well known to those skilled in the art. As illustrated in FIG. 1, preferably the complementary closure profiles 20, 22 have come from extrusion on the internal face of the sheets 16, 18 making up the bag.

However, according to an alternative embodiment, the closure profiles 20, 22 can be formed initially on respective support webs 21, 23 attached to the internal surface of the sheets 16, 18, at the mouth 12 of the bag, as is illustrated it in figure 2.

The connection between the webs 21, 23 and the films 16, 18 can be carried out by any suitable conventional means, for example by hot welding or gluing. The use of closure profiles not extruded from the films 16, 18, but reported by welding or gluing is illustrated in the accompanying drawings only in Figure 2, that is to say only in a application to the embodiment of FIG. 1. However, the use of such closure profiles 20, 22 attached to the film 16, 18 may be applied to all of the alternative embodiments in accordance with the invention, in particular those illustrated in the accompanying drawings and described below. It will be noted that, according to the main characteristic of the invention, the film 16, 18 is provided on its outer surface and at the level of the mouth 12 with the bag of extra thicknesses coming from extrusion. Each additional thickness 30, 32 defines a recess 31, 33 directed towards the bottom of the bag 14. This recess 31, 33 is intended to serve as a retainer for a cursor 50. According to the embodiment illustrated in the appended figures, these recesses 31, 33 are planes and perpendicular to the outer surface of the film 16, 18. As a variant, it is possible to provide slightly different inclinations, or else a slightly rounded shape for the recess 31, 33. The cursor 50 can be the subject of numerous conventional embodiments. The cursor 50 can in particular be in accordance with the provisions described in document EP-A-0479661.

For this reason, the cursor 50 will not be described in detail later. Note, however, that preferably the cursor 50, made of plastic, has two lateral wings 52, 54 connected together at a base 56 and which define with an elongated central sole (not shown in the figures appended to the level of the location of the illustrated cutting plane) two converging passage lanes for the complementary nestable closure profiles 20, 22. Thus, when the relative direction of movement of the cursor 50 relative to the closure profiles 20, 22 tends to move the cursor 50 by forcing the closing profiles 20, 22 in engagement, the bag is closed. When the cursor 50 is moved in the opposite direction, the bag is opened. However, it will be noted that, moreover, in the context of the present invention, the lateral wings 52, 54 are provided at their free end opposite the connection base 56, with a respective return 53, 55, directed towards the inside, that is to say to the film 16, 18. These returns 53, 55 take position behind the offset 51, 53. Thus, a person skilled in the art will understand that the extra thicknesses 30, 32 limit the risk of inadvertent withdrawal of the cursor 50.

During the establishment, the crossing of the extra thicknesses 30, 32 by these returns 53, 55, can be obtained either by elastic deformation of the material making up the cursor 50, or by hinge effect, the lateral wings 52, 54 being articulated on the connecting base 56 and associated with locking means once the position of use has been obtained, as is well known to those skilled in the art. The films 16, 18 comprising extra thicknesses 30, 32 coming from extrusion and the closure profiles 20, 22 can 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. Another embodiment has been illustrated in FIG. 3 according to which the extra thicknesses 30, 32 have a variable thickness, increasing in the direction of the recesses 31, 33. This arrangement has in particular the purpose of facilitating the engagement of the cursor 50 on the extra thicknesses 30, 32.

Is illustrated in Figure 4, an alternative embodiment according to which the bag 10 comprises an anti-violation veil 40 at its mouth 12. This anti-violation veil 40 is formed of a bellows folded inwardly of the bag , at the mouth 12 in the continuity of the films 16, 18 defining the main walls of the bag.

In this case, preferably, the bottom 14 is formed by welding or gluing the opposite free end of sheets 16, 18 as seen in FIG. 4.

Such a bellows 40 directed towards the inside of the bag can be shaped by any suitable known means, for example using a blade urging the bellows 40 inwards between the sheets 16, 18, as is well known. of those skilled in the art.

According to this embodiment illustrated in Figure 4, the complementary closure profiles 20, 22 are formed at the mouth on the facing surfaces of the sections 42, 44, forming the aforementioned bellows 40.

Note that the closure sections 20, 22 are thus actually formed on the outer surface of the film making up the bag. The extra thicknesses 30, 32 coming from extrusion are for their part provided on the external surface of the sheets 16, 18 as mentioned previously.

Again the extra thicknesses 30, 32 define respective recesses 31, 33 cooperating with the returns 53, 55 of the cursor 50. According to the embodiment illustrated in FIG. 4, the closure profiles 20, 22 have come from extrusion with the film making up the bag. However, as a variant, as indicated above, the closure profiles 20, 22 could be provided on respective webs 21, 23 attached, for example welded or glued to the sections 42, 44. According to the variant illustrated in FIG. 4, the extra thicknesses 30 , 32 are of constant thickness over their entire width.

On the other hand, according to the variant illustrated in FIG. 5, the extra thicknesses 30, 32 have an increasing thickness from the mouth of the sachet towards the recesses 31, 33. Those skilled in the art will easily understand, that in a conventional manner in itself, it is necessary to break the anti-violation veil 40 to access the product contained in the bag 10.

Thus, the state of the veil 40 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 veil 40, the latter can be provided, in a manner known per se, with a line of weakness or precut, for example at mid-width, as illustrated diagrammatically under the reference 46 in FIGS. 4 and 5.

In Figure 6, there is shown schematically a film according to the alternative embodiment illustrated in Figure 5, at the extrusion outlet.

The extrusion process by vertical draft around an air bubble of controlled volume at the outlet of an extruder being known to those skilled in the art, the extrusion process will not be described in more detail by the following. Of course, it suffices to fold the film thus produced onto itself with conformation of the bellows 40 to obtain the configuration shown in FIGS. 4 and 5.

Schematically shown in Figures 7a and 7b an installation for the production of bags according to the present invention.

We distinguish in Figure 7a an extruder 100 at the outlet of which a tubular film 110 is extruded by vertical traction around an air bubble 112 of controlled volume. The shape of the die must be adapted to the profile of the film sought. That is to say that the interval between the internal punch and the external punch composing the die at the outlet of the extruder 100 must define a space corresponding to the complementary closure profiles 20, 22 sought (in the case where the profiles closure came from extrusion with the film) and especially a space corresponding to the extra thicknesses 30, 32 sought. After extrusion, the film 110 is directed to the stations for producing bags illustrated in FIG. 7b.

In the case where a double film is extruded, as shown diagrammatically in FIG. 8 (that is to say in the case where a film capable of producing two sachets is simultaneously extruded in tubular form 110, ie a film composed of two pairs of closure sections 20, 22 and extra thicknesses 30, 32) there is provided a first station 130 for cutting the film and orienting the two film elements thus split towards respective processing tracks.

In this figure 8, there is shown diagrammatically under the reference P the sectional plane of the tubular film, operated at station 130, intended to separate the two film elements making up the two respective sachets.

More precisely in FIG. 8, a tubular casing corresponding to a film intended for the embodiment of FIG. 1 is shown diagrammatically, with extrusion of the beads 30, 32 towards the outside and extrusion of the profiles 20, 22 on the inside. The reverse arrangement can be envisaged, that is to say with extra thickness 30, 32 inwards and profiles 20, 22 on the outside of the tubular casing. Furthermore, the double extrusion system shown diagrammatically in FIG. 8 can also be applied for the film intended for sachets comprising an anti-violation veil 40 as illustrated in FIGS. 4 and 5 in particular. Again, the extra thicknesses 30, 32 and profiles 20, 22 can be extruded on the inside or on the outside of the film. We then find in Figure 7bun 140 position of installation of the cursor

50. This station 140 can generally comply with the provisions described in documents EP-A-51010 and EP-A-102301.

Essentially such a station 140 comprises means adapted to sequentially convey sliders 50 laterally, in the open position, on the edge of the mouth of the bags and to close these sliders 50 on the sections 20, 22 and extra thicknesses 30, 32 , after engagement of the central sole of the slider between the sections 20, 22.

In FIG. 7b, there have been shown diagrammatically under the references 150, 160 two stations making up the end of the production line and which correspond respectively to a station for cutting and sealing the sachet and to a packaging station.

As illustrated in FIGS. 9 and 10, according to another alternative embodiment, provision may also be made to extrude on the facing surfaces of the sheets of the film making up the mouth of the bags and carrying the closure profiles 20, 22 of the complementary beads 27, 28, or even a single bead 27 on one of the film sheets in order to perfect the sealing of the sachet. Such an arrangement with complementary sealing beads is described in particular in the patent application filed in France by the Applicant under No. 97 04394. It will be noted that according to FIG. 9, the beads 27, 28 are provided on the internal surface of the movie. These two beads 27, 28 could be replaced by a single bead 27, as illustrated in FIG. 10. Furthermore, according to FIG. 10, the bead 27 is provided on the external surface of the film, the bead 27 being found on the inside. of the anti-violation bellows or veil 40 once it is folded towards the inside of the bag. Here again, the single bead 27 could be replaced by two complementary beads 27 and 28, as illustrated in FIG. 9. The sachets obtained in the context of the present invention offer numerous advantages compared to known prior sachets.

In particular, they allow a high productivity rate and good sealing of the bags. Furthermore, the cooperation defined between the recesses 31, 33 formed by the extra thicknesses 30, 32 and the returns 53, 55 of the sliders 50 makes it possible to avoid any untimely withdrawal of the sliders 50 under the effect of the internal pressure in the sachets or else under the effect of a solicitation by a user. Where appropriate, in the context of the embodiments illustrated in FIGS. 4 and 5 for which an anti-violation veil 40 is provided, a weld may be provided between the internal surfaces of the main sheets 16, 18 making up the bag and the sections 42, 44 forming the bellows corresponding to the anti-intrusion veil 40 as shown diagrammatically under the reference 60 in FIG. 11.

Preferably, but not limiting, the dimensions of the extra thicknesses 30, 32 are preferably the following: thickness at the level of the recesses 31, 33 advantageously between 0.5 and 3 mm, preferably between 0.7 and 2 mm, and very preferably of the order of 1 to 1.5 mm, and width preferably between 0.1 and 1.5 cm, and very preferably of the order of 0.9 cm.

Of course the present invention is not limited to the particular embodiments which have just been described, but extends to all variants in accordance with its spirit. Thus, as illustrated in FIGS. 12 and 13, according to yet another variant, structures of complementary shapes can be provided respectively on the recesses 31, 33 of the extra thicknesses 30, 32 and on the surfaces facing the returns 53, 55 trained on cursor 50.

There are shown grooves 70 formed on the recesses 31, 33 and complementary ribs 72 on the returns 53, 55 of the cursor, in FIG. 12. FIG. 13 shows ribs 74 formed on the recesses 31, 33 and complementary grooves 76 on the returns 53, 55.

These complementary shapes 70/72 and 74/76 can of course be the subject of numerous variant embodiments, in particular as to their number, their section and their location.

They improve the retention of the cursor 50 on the bag.

Claims

1. Bag comprising complementary closing profiles (20, 22) and a slider (50) for actuating the profiles (20, 22) during closing and opening, characterized in that it also includes extra thicknesses (30, 32) coming from extrusion on the film making up the bag opposite the closure profiles (30, 32), which extra thicknesses (30, 32) have a thickness of between 0.5 and 3 mm at the cooperating recess with the cursor (50).

2. Bag according to claim 1, characterized in that the closure profiles (30, 32) are themselves extruded on the film making up the bag (10).

3. Bag according to claim 1, characterized in that the complementary closure profiles (20, 22) are produced on respective support webs (21, 23) fixed, for example by gluing or welding, on the film (16, 18) comprising the extra thicknesses (30, 32) coming from extrusion.

4. Bag according to one of claims 1 to 3, characterized in that the thickness of the extra thicknesses (30, 32) at the level of the recess (31, 33) cooperating with the cursor (50) is between 0.7 and 2mm and very preferably between 1 and 1.5mm.

5. Bag according to one of claims 1 to 4, characterized in that the width of the extra thicknesses (30, 32) is preferably between 0.1 and 1.5 cm, very advantageously of the order of 9mm.

6. Bag according to one of claims 1 to 5, characterized in that the extra thicknesses (30, 32) define recesses (31, 33) intended to cooperate with the cursor (50), oriented perpendicularly to the component film the bag.

7. Bag according to one of claims 1 to 6, characterized in that the cursor (50) has returns (53, 55) directed towards the film (16, 18) composing the bag and cooperating with recesses (31 , 33) formed by the extra thicknesses (30, 32).

8. Bag according to one of claims 1 to 7, characterized in that the film (16, 18) comprising the extra thicknesses (30, 32) come extrusion and / or complementary closure profiles (20, 22) are made of polyolefin.

9. Bag according to one of claims 1 to 8, characterized in that the film (16, 18) comprising the extra thicknesses (30, 32) coming from extrusion and / or the complementary closure profiles (20, 22) are made of the material chosen from the group comprising low or high density polyethylenes and polypropylene.

10. Bag according to one of claims 1 to 9, characterized in that the extra thicknesses (30, 32) have a variable thickness over their width, increasing in the direction of the recesses (31, 33) cooperating with the cursor (50) .

11. Bag according to one of claims 1 to 10, characterized in that it comprises an anti-violation veil (40) formed by a bellows folded towards the inside of the bag and which carries the complementary closure profiles (20 , 22).

12. Bag according to claim 11, characterized in that it comprises a connection between the sections of film making up the bellows corresponding to the anti-violation veil (40) and the internal surface of the main film sheets (16, 18) on which are extruded the extra thicknesses (30, 32).

13. Bag according to one of claims 1 to 12, characterized in that it further comprises at least one bead (27, 28) co-extruded with the extra thicknesses (30, 32) at the surface level (s) next to the film to perfect the seal of the bag.

14. Bag according to one of claims 1 to 13, characterized in that the extra thicknesses (30, 32) protrude from the outer surface of the bag.

15. Bag according to claim 7, characterized in that the recesses (31, 33) formed on the extra thicknesses (30, 32) and the returns (53, 55) cooperating formed on the cursor (50) comprise structures of shapes complementary (70, 72; 74, 76) of the complementary groove / rib type.

16. Film for the production of a bag according to one of claims 1 to 15, characterized in that it includes extra thicknesses (30, 32) extruded on the film, having a thickness between 0 , 5 and 3 mm, at a recess.

17. Film according to claim 16, characterized in that it further comprises complementary closure profiles (20, 22) co-extruded.

18. A method of manufacturing a film according to one of claims 16 or 17, and / or a sachet according to one of claims 1 to 15, characterized in that it comprises step d extrusion on the film of extra thicknesses (30, 32), having a thickness of between 0.5 and 3 mm, at a recess.

19. The method of claim 18, characterized in that it further comprises the step of co-extruding the complementary closure profiles (20, 22).

20. Method according to one of claims 18 or 19, characterized in that it further comprises the step of co-extruding at least one sealing bead (27, 28).

21. Method according to one of claims 18 to 20, characterized in that it comprises the step of extruding a tubular envelope comprising two pairs of extra thicknesses (30, 32), followed by a cutting step tubular film for the separation of two films capable of each forming a respective sachet.

22. Machine for implementing the method according to one of claims 18 to 21, characterized in that it comprises means (100) for extruding a film comprising extra thicknesses (30, 32), having a thickness between 0.5 and 3 mm, at a level.

23. Machine according to claim 22, characterized in that it further comprises means (100) for extruding complementary closure profiles (20, 22).

24. Machine according to one of claims 22 or 23, characterized in that it further comprises means capable of extruding at least one sealing bead (27, 28).

25. Machine according to one of claims 22 to 24, characterized in that it comprises means adapted to sequentially convey sliders (50) laterally, in the open position, on the edge of the mouth of the sachets and to close these sliders (50) on the profiles (20, 22) and extra thicknesses (30, 32), after engagement of a central sole of the slider between the profiles (20, 22).