FR2944780A1 - DEVICE FOR PACKAGING AND DISPENSING THE BOTTLE-POCKET TYPE - Google Patents

Abstract

The invention relates to a device of the pocket-bottle type for the packaging and dispensing of fluid products. The device comprises a flexible bag placed in a rigid bottle, associated with a pump or a valve for expelling the product contained in the bag, the bag comprising a cylindrical wall constituted by at least one sheet (1) wound in a cylinder of which one of the lateral edges is sealingly attached to a solid flange forming the bottom of the pocket, and the other is sealingly attached to an annular flange forming a ring for fixing to the flask, and the two longitudinal edges of the flange. sheet are tightly attached to one another and the edge of the inner edge is masked by a flexible strip of cover (6). Application to reduce the risk of contamination of the product contained in the pocket.

Description

The present invention relates to a device for packaging and dispensing fluid products, and more particularly to a flexible pouch for a device for packaging and dispensing fluid, liquid or pasty products of the pocket-bottle type, that is to say comprising a flexible pouch placed in a rigid container and associated with a pump or a valve, to keep the fluid in the flexible pouch safe from air in good conditions, and ensure its distribution out of the pocket by operating the pump or valve. The devices for packaging and dispensing fluids of the pocket-bottle type are well known. These devices generally comprise a rigid-shell container in which is placed a retractable flexible bag, which retracts as the product is extracted. The expulsion of the product out of the bag can be obtained by means of an "airless" pump or without air intake, or under the pressure of a propellant gas acting in the bottle on the wall of the bag. In the case of the expulsion of the product out of the pocket by means of a pump without air intake, a vent is provided, generally in the bottom or in the neck of the bottle, to allow the outside air to penetrate in the space between the bottle and the bag each actuation of the pump and thus allow the bag to retract, maintaining sufficient pressure on its walls. An embodiment according to this technique is described in patent FR 2,723,356 relating to a device comprising a flexible plastic bag, such as polyethylene or polypropylene, placed in a rigid container whose neck has an air inlet. Another example of a pocket bottle is described in patent FR 2,827,844 relating to a device comprising a sealed flexible bag placed in a rigid bottle, associated with a pump or a valve, in which the bag comprises a cylindrical wall constituted by a sheet metal or plastic material wound on the edges of two flanges of which

B1874EN one forms the bottom of the pocket and the other a ring fixing the bottle and the pump or the valve. WO 97.20757 discloses a method of manufacturing a tubular plastic bag for an aerosol, the opening is welded to a ring while the other end is folded and sealed to form the bottom of the bag. The products contained in the bags are often sensitive to oxidation under the action of oxygen in the air and can degrade if air is introduced into the pocket due to a lack of tightness. Sealing defects are most often found at the junction of the pocket and the pump. They can also result from a certain porosity of the materials used for the realization of the pocket. In addition, the pocket wall of the known devices can form folds by retracting, and these folds may cause tears likely to pass air which then reaches the inside of the pocket, and therefore compromises preserving the integrity of the product contained therein. Finally, the folds formed by the wall of the pocket during its retraction generate product retention volumes and thus limit the effectiveness of the distribution thereof. A technique to limit the risk of tearing of the pocket is described in patent FR 2,770,834, which provides to include in the pocket, made of flexible material such as plastic or aluminum foil, a free float preventing too strong retraction of the pocket and thus limiting the risk of tearing. However, this technique has the disadvantage of forming large retention volumes. Pouch bottles are commonly manufactured by extrusion or injection of plastics. The bottle may be manufactured by stamping in the case of a metal wall such as aluminum, or by injection or injection blow molding in the case of a plastic wall, while the flexible bag is generally manufactured by injection blow molding or extrusion blowing of polyethylene or polypropylene into a suitable mold. The bags can also be made of aluminum sheets or multilayer plastic / aluminum type have good sealing qualities of their wall, as in the patent FR 2,827,844 supra. The pockets of this type are made in the form of superimposed sheets, welded by their edge, adapting to a collar or a rigid ring. The manufacture of such pockets is relatively simple, but it has the disadvantage that the junction area of the two opposite edges of the sheet to form the cylinder has an extra thickness. In addition, this extra thickness reveals the thickness of the layer forming the sheet, and the risk of migration of traces of compounds contained in the layer to the product introduced into the bag is not negligible in this unprotected area, especially in the case of a multilayer film comprising a metal layer. In addition, it is often difficult to obtain and maintain a good seal of the edges of metal foils, for example aluminum, because of the deformations and the tensions to which they are subjected during use. If the welding is reinforced and forms a fold to ensure tightness, the result is a rib that affects the good retraction of the pocket and the return of the products it contains. There is therefore a need for pouch-type devices having good safety by reducing as much as possible the risk of contamination between the material constituting the wall of the pouch and the product it contains. There is also a need for devices of the pocket-bottle type, of simple and inexpensive manufacture, comprising a pocket that can easily adapt to the quantities of products that it is desired to introduce and to the volume of the bottle, without excessive dead volume between pocket and bottle, without loss of waterproofness and easily recyclable.

The subject of the present invention is precisely a device for packaging and dispensing a fluid product of the pocket-bottle type that has good safety with regard to the risks of contamination of the products contained in the bag. The invention also relates to a pocket-bottle manufacturing process that can use simple or complex materials according to the intended use, easily recyclable, and using minimal amounts of material, for the bottle and for the pocket. The fluid product conditioning and dispensing device according to the present invention is of the type comprising a sealed flexible bag placed in a rigid bottle, associated with a pump or a valve, the bag comprising a cylindrical wall formed by at least one rolled sheet according to a cylinder of which one of the lateral edges is sealingly attached to a solid flange forming the bottom of the bag, and the other is sealingly attached to an annular flange forming a ring for fixing to the bottle, and it is distinguished in particular in that the two longitudinal edges of the sheet are fixed one on the other in a sealed manner and the edge of the inner edge is masked by a flexible strip covering. According to one embodiment of the invention, the cover strip is fixed on each of the two longitudinal edges of the sheet, on either side of their junction on the inner wall of the sheet. According to another embodiment of the invention, the cover strip wraps around the edge of the inner edge of the sheet and folds between the two edges. It is then welded together with the edges of the sheet during the formation of the cylindrical tube. The width of the cover strip varies according to the dimensions of the pocket, but it is generally between 2 and 10 mm, and preferably between 4 and 6 mm.

As indicated above, the sheet used to form the wall of the bag may consist of various simple or complex materials, depending on the intended use. Its thickness can vary from approximately 20 μm to 250 μm and is preferably between 50 μm and 150 μm in order to ensure the best operating conditions, in particular easy retraction of the bag into the bottle as it progresses. empty, so as to provide an excellent refund rate, greater than 90%. These values may vary depending on the materials used. The sheet, monolayer or multilayer, is fixed by its edges to the periphery of each flange, and closed along a generatrix of the cylinder. According to one embodiment, the cylindrical pocket comprises a multilayer complex combining several metal films, or a metal sheet coated with a plastic film on at least one of its faces. This multilayer complex is wound on two flanges which can be for example metal or plastic. A particularly advantageous embodiment comprises an aluminum foil interposed between at least two plastic films. The plastic films of the multilayer complexes may be chosen from a polyethylene, a polypropylene, a polyamide, etc.

The multilayer sheet is fixed by its edges to the periphery of each flange, and closed along a generatrix of the cylinder. According to another embodiment of the invention, the multilayer film is a plastic / barrier polymer / plastic material complex, and for example an EVOH film interposed between two polyethylene or polypropylene films. EVOH is an ethylene vinyl alcohol polymer with good gas barrier properties, particularly oxygen and water vapor.

The complex may also comprise four layers, polyethylene / polyamide / aluminum / polyethylene terephthalate, or polyethylene / polyethylene terephthalate / aluminum / polyethylene. This last multilayer structure has the advantage of facilitating edge-to-edge fixing after winding the sheet, by bonding or by welding, since the inner part of one edge of the sheet is applied to the outer part of the other edge, which is in the same material. Such multilayer composite coating is particularly useful when a tight seal is essential, or when the nature of the product in the pocket requires. According to a variant, an aluminum foil wound on two metal or plastic flanges may be used, two opposite edges of the sheet being welded to one another along a generatrix of the cylinder. In all cases, a cover strip is placed on the inner face of the sheet forming a tube, on the junction of the two edges, as indicated above. The covering strip is preferably made of a material identical to that constituting the inner layer of the sheet. For example, it is advantageous to use a sheet comprising at least one layer of polyethylene as an inner layer, and a cover strip made of the same polyethylene. This ensures a continuity of the material forming the inner layer of the pocket in contact with the product that is introduced. The fluid product is in contact limited to a single material. In addition, once welded, the cover strip has substantially the same thickness as the inner layer of the sheet.

According to another variant, a flexible paperboard sheet or a polymer / paper / polymer complex, preferably polyethylene / paper / polyethylene, is used. This type of material has the advantage of being much more easily recyclable than PE / PET / aluminum / PE multilayers used in the technical field.

As indicated above, the metal sheet, or the multilayer sheet, is fixed on the periphery of each of the two flanges, preferably by gluing or welding, depending on the nature of the material used for the flanges.

The method of the invention consists firstly in cutting the sheet to the desired size, in welding the two opposite edges of the sheet, from the inside to the outside to form an open tubular pocket which is then fixed through its openings on the flanges, then the bag is introduced into the rigid bottle where it is held by the annular flange forming a ring. Then the cover strip is cut and welded on the sheet, inner side. The sheet is then wound on itself, keeping the cover strip on the inside, and taking care that it covers the contact area between the ends. The welding is then carried out, and a welded tube is obtained, with continuity of the inner zone. The attachment of the edges to one another, then to the flanges, can be performed by conventional welding techniques, for example ultrasonic welding, impulse, friction, or heat. The thermal welding technique which is more suitable for the materials used to form the wall of the pocket is preferably used. Fixing can also be done by gluing but only if the products that the bag is intended to contain do not risk any adverse effect resulting from possible contamination by the glue components. The sheet initially has a flattened shape, requiring the use of appropriate tools to shape it and then introduce the product. The operations of filling the bag used in the invention do not require first to empty the bag before proceeding to a partial filling, then to operate in a final step under neutral gas, unlike most known pockets of the technique.

One of the advantages of the process of the invention is that it makes it possible to obtain pockets of relatively large volumes (more than 150 ml for example) of perfectly cylindrical shape because of the welding mode. The method according to the present invention has the particular advantage of allowing the manufacture of pouches whose volume is easily adapted to that of the bottle and the amount of product that must be introduced into the bag. This is particularly advantageous industrially since conventional techniques, because of their cost, involve limiting the range of bottles to a few models of predetermined dimensions, and for example it is commonly proposed rigid bottles whose volume is 30, 60 or 90 ml and therefore a bag whose content is 65 ml, for example, can be introduced into a 90 ml bottle, resulting in a large dead volume between the bag and the bottle. According to the technique of the invention, the volume of the bag can be easily adapted to that of the bottle by simply adjusting the height and diameter of the cylinders constituting the bag and the bottle, it is possible to reduce the dead volumes.

This provides an additional advantage in the case of relatively volatile products, such as alcohols, contained in the bag, which can partially pass through the wall, depending on the materials used: the reduced dead volume is quickly saturated, which then limits the losses of product .

An exemplary embodiment of a pocket-bottle according to the present invention is described below with reference to the accompanying drawings which show: Figure 1: a perspective view of a sheet wound to form a tubular pocket according to a known technique.

Figure 2 is a perspective view of a sheet according to the technique of the present invention, with a cover strip on the inner face of the tube. Figure 3 is a perspective view of a variant of the invention where the cover strip is on both sides of the inner edge of the sheet.

Figure 4: an exploded view of a pocket bottle whose bottle contains the complete bag comprising the tube of Figure 2 with the two flanges. Figure 1 shows a sheet (1) consisting of an aluminum foil (2) covered on each of its two faces by a layer of polyethylene. Thus the sheet comprises an outer polyethylene film (3) and an inner polyethylene film (4). Once the sheet (1) wound, its two ends are superimposed at the area (5), the inner face close to the edge being placed on the outer face close to the other edge. The width of the superposition area of the two edges of the sheet is about 5 mm. The two edges are attached to one another by the width of the sheet is variable and corresponds to the height of the pocket, once the tube formed and placed on the flanges. Figure 2 clearly shows the polyethylene strip (6) placed on the inner face of the sheet (1). This band (6), with a width of about 6 mm, covers the overlap of the two edges over the entire width of the sheet (1) and masks the apparent edge of the inner edge. The identity of the material constituting the covering strip (6) and the inner layer on the one hand, and the outer layer of the sheet on the other hand, facilitates the attachment by welding the two edges one over the other , and the covering strip of thickness usually between 30 and 75 microns, on the junction edges. Thermal welding is preferably carried out. In addition, the same material, in this example polyethylene, is used throughout the inner surface of the sheet which is subsequently in contact with the product in the pouch. There is therefore no break in the quality of the material forming the inner face of the pocket. The polyethylene cover layer makes it possible to mask the edge of the inner edge of the sheet and to prevent any contact of the aluminum with the product introduced into the pocket, and its small thickness, of the order of 30 at 75 ° gym, and preferably about 50} gym, causes only negligible extra thickness. Figure 3 shows an alternative embodiment of the invention where the cover strip (6) wraps around the edge of the inner edge of the sheet (1). This variant facilitates the welding operations depending on the tooling used since the cover strip (6) is first fixed and welded to one of the edges 10 of the multilayer sheet (1), then the sheet is wound into cylinder and welding of the two edges and the cover strip is then achieved. Figures 2 and 3 show the respective positions of the sheet (1) and the strip (6) before the welding operation. FIG. 4 shows the assembly of the sheet (1), wound in a closed cylinder by the covering strip (6), with the flanges (7, 8) and the insertion of the assembly into the rigid bottle (9). ). The annular flange (7) 20 constitutes a fixing ring to the bottle (9) while the full plate flange (8) constitutes the bottom of the bag. An air circuit (not shown) is provided, according to a usual technique, in the pump or in the annular flange forming a fixing ring to allow the passage of air from the outside to the space between the pocket and vial. Means are provided for the air circuit to be opened only when the pocket bottle is used, for example by a known shutter system opening only in the event of pressure on the actuating pusher of the pump so as to allow only a volume of air equivalent to the volume of fluid expelled from the pocket. For example, the shutter means of the air circuit may be constituted by valves, which remain closed until the pump is actuated. According to a variant (not shown) this air circuit can be replaced by a simple vent in the bottom of the bottle. If necessary, this vent may be equipped with a valve and a filter. As shown in Figure 4, it is easy to play over the width and height of the sheet to fit the bag to the volume of the bottle and limit the dead volume between the two.

Claims (8)

REVENDICATIONS1. Device for packaging and dispensing fluid product of the pocket-bottle type comprising a flexible bag placed in a rigid bottle, associated with a pump or a valve for expelling the product contained in the bag, the bag comprising a cylindrical wall constituted by at least one sheet wound in a cylinder, one of whose side edges is sealingly attached to a full flange forming the bottom of the pocket, and the other is sealingly attached to an annular flange forming a fixing ring to the bottle, characterized in that the two longitudinal edges of the sheet are fixed to each other in a sealed manner and the edge of the inner edge is masked by a flexible strip covering. 2. Device according to claim 1, characterized in that the covering strip is fixed on each of the two longitudinal edges of the sheet, on either side of their junction on the inner wall. 3. Device according to claim 1, characterized in that the covering strip wraps around the edge of the inner edge of the sheet and folds between the two edges. 4. Device according to any one of the preceding claims, characterized in that the sheet constituting the wall is monolayer or multilayer. 5. A fluid product conditioning and dispensing device according to claim 4, characterized in that the multilayer sheet comprises an aluminum sheet interposed between at least two plastic films selected from a polyethylene, a polypropylene, a polyamide. 6. Fluid product conditioning and dispensing device according to claim 4, characterized in that the multilayer film is a polyethylene / paper / polyethylene complex. 7. fluid product conditioning and dispensing device according to any one of the preceding claims, characterized in that the covering strip is in a material identical to the inner layer of the sheet. 8. fluid product conditioning and dispensing device according to claim 7, characterized in that the sheet comprises at least one layer of polyethylene as an inner layer, and the cover strip is made of a single polyethylene.