BAG INCLUDING CLOSURE PROFILES ACTUATED BY A SLIDER

Abstract

The invention relates to a bag (1) that comprises two substantially parallel sheets (12, 13) defining the main walls thereof, complementary closing profiles (2, 3) respectively attached to said sheets (12, 13), and a slider (5) for actuating the profiles (2, 3) upon opening or closing. The bag is characterised in that at least one of said sheets (12, 13) includes, on the outer face thereof, in the vicinity of the gripping area of the slider (5) and parallel to the movement direction of the latter, a strip-shaped bead defining a build up having a thickness and a width sufficient for locally modifying the deformability thereof.

Description

The present invention relates to the field of bags comprising mating closure profiles respectively actuated upon opening and closing by a slider.

These bags have already been of great help. Indeed, the sliders facilitate the opening and closing of the bags, so that their presence is strongly appreciated by elderly or blind persons.

These bags include two generally parallel sheets forming its main walls, mating closure profiles attached on these sheets, as well as a slider for actuating the profiles upon closing and opening;

The slider has a cross-section in the shape of an upside down “U”, its two parallel flanks coming on either side of the aforementioned sheets, facing the profiles.

Automated machines are used for placing sliders on such bags.

To summarize, a set of contiguous bags, bound to each other, moves stepwise past a machine regularly supplied with sliders. Every time a bag is immobilized in front of the machine, means proceed with translationally placing a slider in the direction of the bag.

Means will bear upon the sheets of the bag, in order to ensure perfect immobilization of the bag during the placement.

However, these sheets generally have the particularity of being extremely deformable, so that in spite of the pressure of said means, relative displacement of the sheet is observed.

The main object of the present invention is to overcome this difficulty, by providing a bag structure with which the automated slider placement is facilitated.

A secondary object of the invention is to propose a bag which moreover has a high seal.

The invention relates to a bag including:

• • two generally parallel sheets forming its main walls;
  • mating closure profiles respectively attached on these sheets;
  • a slider for actuating the profiles upon closing and opening.

According to the invention at least one of said sheets includes on its outer face, in proximity to the gripping area of said slider and parallel to the direction of displacement of the latter, a strip-shaped bead forming an overthickness with sufficient thickness and width for locally modifying the deformability thereof.

According to other advantageous but non-limiting features:

• • said strip-shaped bead is capable of locally increasing rigidity;
  • said bead has a width comprised between 5 and 15 millimeters and a thickness comprised between 100 and 1,000 micrometers;
  • said bead also forms an abutment means capable of immobilizing said sheets relatively to said slider along a direction generally perpendicular to the axis of displacement of the slider;
  • said slider comprises flanks, the inner surface of each of them bears a boss directed towards the opposite flank, so that the sheets forming the main walls converge towards each other, from said profiles to said bosses;
  • it includes, parallel to said profiles, between said sheets and at the mouth of the bag, additional raised means positioned on the inside of the closure profiles, designed in order to ensure the seal by forming a barrier between the sheets in the bag-closing position, these additional means being adapted so as to be urged towards their sealing position by the slider when the latter is displaced towards the bag-closing position, and that said bead is located in the vicinity of said bosses;
  • said bead and said sheets are integrally formed with the same material;
  • said bead is co-extruded with said sheets and consists of a different material, for example in high density polyethylene while the sheets consist of low density polyethylene;
  • said bead is an element added to said sheets,
  • said bead consists of a deformable, notably rubber-based material.

Other features and advantages of the present invention will become apparent upon reading the detailed description which follows of certain preferred embodiments.

This description will be made with reference to the appended drawings wherein:

FIG. 1 is a schematic sectional view of a first embodiment of the bag of the invention;

FIGS. 2-4 are also sectional views of three other embodiments of the bag.

The bag illustrated in FIG. 1 has a structure generally known from document WO-A-99/65353 about which comments were made above.

This bag 1 includes a mouth 10 and a bottom 11. It consists of two main sheets in plastic material, referenced as 12 and 13.

These sheets are connected together at the bottom 11. In the embodiment illustrated here, both sheets are integral with each other from the start. However, in an embodiment not shown, both of these sheets may be initially separated and then superposed and attached to each other upon manufacturing the bag.

At the mouth 10, both sheets 12 and 13 are provided with mating closure profiles 2 and 3.

These profiles may be the object of many embodiments. The invention is not limited to the specific embodiment illustrated in FIG. 1.

In the case illustrated here, the profiles 2 and 3 are respectively of the male and female type, as this is well known to one skilled in the art. However, the invention may apply to other types of profiles, notably of the type with mating hooks.

In the embodiment of FIG. 1, the profiles 2 and 3 are integrally extruded with the sheets 12 and 13 which make up the bag.

However, in an alternative embodiment not shown, these mating profiles may be borne on supporting webs added onto the sheets 12 and 13, for example by hot welding or adhesive bonding.

As mentioned above, the bag further includes a slider 5 adapted for actuating the profiles 2 and 3 upon closing and opening.

This slider may be the object of many standard embodiments. A typical example of a slider is described in document EP-A-0 479 661. In the embodiment presented here, the slider made in plastic material includes two side wings 51 and 52 (or flanks) connected together at a base 50 and which define with an elongated central sole (not visible) two converging passage corridors for the mating closure profiles 2 and 3 which fit together.

Thus, when the relative displacement direction of the slider 5 relatively to the closure profiles 2 and 3 tends to displace the slider by forcing engagement of the profiles, the bag is closed. When the slider is displaced in the opposite direction, the bag is opened.

According to the invention, at least one of the sheets 12 and 13 includes on its outer face, in proximity to the gripping area of the slider 5 (by gripping area of the slider is meant the area of the sheets 12, 13 of the bag located facing its flanks 51 and 52) and parallel to the displacement direction of this back, a strip-shaped bead 6 forming an overthickness on the sheets, with sufficient width and thickness in order to locally modify the deformability thereof.

In the example illustrated here, each sheet 12 and 13 has a strip-shaped bead 6.

This is a bead added to the sheets, for example by adhesive bonding or welding.

In another embodiment, it may be integrally formed with them in the same material. Under such an assumption, the bead is for example obtained by simple extrusion, so that it forms a localized overthickness of the material of the sheets 12 and 13.

In one alternative, it may be obtained by co-extrusion, so that it consists of a material different from that of the sheets.

When the sheets 12 and 13 are particularly deformable, the strip-shaped bead 6 locally increases the rigidity of the bag, so that the pressing means of an automated machine may enter in intimate contact with the latter with view to perfect immobilization.

When the bead is added to the sheets, it may be made in the same material as them, or in another material, preferably more rigid. An example is medium or high density polyethylene.

In any case, it is the wide shape and the overthickness of the bead which contributes to locally modifying the deformability of the bag.

As an indication, the bead 6 has a width comprised between 5 and 15 millimeters and a thickness comprised between 200 and 1,000 micrometers.

If necessary, the upper surface of the bead may be provided with portions in relief or other protrusions facilitating gripping of the bag.

Moreover, the bead may consist of a relatively deformable material, for example based on rubber or similar to rubber. In this case, the bulk formed by the bead locally rigidifies the bag, but its characteristics resulting from its “rubbery” nature facilitate its gripping.

In the example of FIG. 2, the free ends 51 and 52 of the flanks of the slider are folded back inwards in order to form a boss 53, respectively 54, directed towards the opposite flank.

The beads 6 and the sheets 12 and 13 will here be integrally formed in the same material. In addition to the aforementioned function, they form an abutment means which opposes the movement of the sheets 12 and 13 in a direction perpendicular to the displacement direction of the slider.

In the example presented here, an analogous bead 7 is placed on the sheets 12 and 13, facing the profiles 2 and 3.

The space which separates both beads 6 and 7 and which materializes a groove 8, is used for improving attachment of the slider 5.

In the embodiment of FIG. 4, the flanks of the slider 5 are also provided with bosses 53 and 54 directed towards each other. The elongated and central sole 55 of the slider is visible there.

Due to the presence of these bosses, the sheets forming the main walls of the bag converge towards each other, profiles 2 and 3 towards (in the direction of) these bosses.

In other words, the main walls from the profiles converge towards each other in the direction of the inner space of the bag.

The bag moreover includes additional raised means 4 which are designed in order to ensure the seal by forming a barrier between the sheets 12 and 13 in the closure position of the bag. They are positioned on the inside of the closure profiles.

In other words, these means 4 are placed on the inner face of each sheet, facing the flanks 51 and 52 of the slider 5 so as to be urged towards their sealing position by the slider when the latter is displaced towards the sealing position.

More specifically, these means 4 each consist of a bead in plastic material which extends parallel to the X-X′ axis of displacement of the slider.

In order to provide the seal, the beads extend exactly facing each other.

But, as discussed above, it occasionally occurs that one of the sheets 12 and 13 of the bag is subject a slight translation perpendicular to the direction of displacement of the slider, so that the beads 4 are not strictly facing each other.

The result of this is then a lack of seal.

But due to the presence of the strip-shaped beads 6, the sheets 13 are immobilized along the general direction perpendicular to the X-X′ displacement axis of the slider 5 by contact between the beads and the bosses 53 and 54.

In other words, the positioning of the sheets is “blocked” relatively to the slider so that the additional sealing means 4 are perfectly facing each other and completely ensure their sealing function.

Moreover, due to the presence of the profiles 2 and 3 on the sheets 12 and 13, these regions of the bag are rigid or not very deformable. Now, the presence of the strip-shaped beads 6 contribute to bringing the sheets 12 and 13 closer to each other.

Claims

1.-10. (canceled)

11. A bag including:

two sheets generally parallel forming its main walls;

mating closure profiles respectively attached on these sheets;

a slider for actuating the profiles upon closing and opening,

wherein at least one of said sheets includes, on its external face, in proximity to the gripping area of said slider and parallel to the displacement direction of the latter, a strip-shaped bead forming an overthickness with sufficient thickness and width for locally modifying the deformability thereof.

12. The bag according to claim 11, wherein said strip-shaped bead is capable of locally increasing the rigidity thereof.

13. The bag according to claim 11, wherein said bead has a width comprised between 5 and 15 millimeters and a thickness comprised between 100 and 1,000 micrometers.

14. The bag according to claim 11, wherein said bead also forms an abutment means capable of immobilizing said sheets relatively to said slider along a direction generally perpendicular to the displacement axis of the slider.

15. The bag according to claim 11, wherein said slider comprises flanks, the inner surface of each of them bearing a boss directed towards the opposite flank, so that the sheets forming the main walls converge towards each other, from said profiles towards said bosses.

16. The bag according to claim 11, which it includes parallel to said profiles, between said sheets and at the mouth of the bag, additional raised means positioned on the inside of the closure profiles, designed for ensuring the seal by forming a barrier between the sheets in a closure position of the bag, these additional means being adapted so as to be urged towards their sealing position by the slider when the latter is displaced towards the closure position of the bag, and that said bead is located in the vicinity of said bosses.

17. The bag according to claim 11, wherein said bead is integrally formed with said sheets in the same material.

18. The bag according to claim 17, wherein said bead is a bead co-extruded with said sheets formed with a different material, for example high density polyethylene, while the sheets consist of low density polyethylene.

19. The bag according to claim 11, wherein said bead is an element added to said sheets.

20. The bag according to claim 17, wherein said bead consists of a deformable material, notably based on rubber.