EP1005431A1

EP1005431A1 - Pressurised dispenser body comprising a metal or copper-asbestos pocket, said pocket and method for obtaining same

Info

Publication number: EP1005431A1
Application number: EP99920892A
Authority: EP
Inventors: Jacques Granger
Original assignee: Cebal SAS
Current assignee: Albea Tubes France SAS
Priority date: 1998-05-20
Filing date: 1999-05-20
Publication date: 2000-06-07
Also published as: WO1999059896A1; BR9906502A

Abstract

The invention concerns a dispenser body (21; 51) with pocket consisting of a rigid metal case (22; 52) containing a metal or copper-asbestos pocket (1; 31) capable of being creased, fixed sealed on the rigid case (22, 52) and having a substantially vertical smooth wall (27, 33) whereof the thickness is close to that of the base (26, 32). Such a pocket is obtained preferably by drawing and ironing.

Description

PRESSURE DISTRIBUTOR BODY HAVING A METAL OR METALLOPLASTIC POCKET, SAID POCKET AND METHOD FOR OBTAINING SAME

TECHNICAL AREA

The invention relates to a distributor body dispensing pressurized liquid to pasty products, said body having a metal or metalloplastic pocket separating the product to be dispensed from the propellant gas.

Such a pocket dispenser is used for cosmetic, pharmaceutical, hygiene or food products.

The invention also relates to the process for obtaining the dispenser housing as well as the preformed pocket used to obtain the housing or the pocket blank and its shaping process after attachment to the housing.

STATE OF THE ART

Pocket dispensers, also called two-chamber aerosols, make it possible to separate the product to be dispensed from the propellant. Sometimes it is sought to avoid contact between the product to be dispensed and the propellant, either for purely mechanical reasons - for example gels are transformed into foam if they are mixed with propellant - or for chemical reasons: reaction of the product with the propellant, oxidation, aging, transmission of odors, etc.

The bag must be waterproof and flexible, waterproof to effectively and durably separate the product from the propellant, flexible to transmit pressure which allows to evacuate the product by opening a valve separating the inside of the bag from the outside

If a plastic bag can be chosen to solve the problem of flexibility, it is recommended to choose a metal bag when the problem of tightness with respect to the propellant gas is a predominant use constraint. Metal, an aluminum alloy preferably, has in fact, due to its low permeation, a gas barrier property clearly superior to that which the best of the plastic materials known at present can have.

A metallic or metalloplastic pocket must also be easily crumpled because it must be able to deform under the effect of the pressure of the propellant gas, occupying a volume which decreases as the consumption of the product

For obvious economic reasons, the bag must initially occupy the largest possible volume to contain the maximum amount of product to be dispensed.

Application EP 0 017 147 discloses a pocket aerosol in which the pocket is introduced into the rigid case after conformation thereof: the pocket has an outside diameter less than the diameter of the orifice of the neck of the rigid case formed during conification. Consequently, the capacity of the flexible bag, that is to say the quantity of product to be delivered, remains limited.

To increase the capacity of the pocket, FR 2 310 287 and EP 0 755 877 recommend introducing a preformed pocket into a cylindrical case blank, then conifying the case and then fixing the pocket by "lifting" it up so that its neck can come out and be folded over the rolled edge of the case. Other documents suggest deforming the pocket after having fixed it on the housing blank. FR 2 140 804 recommends simultaneously shaping the rigid case and the pocket by joining them together before the necking is formed using an adhesive material. EP 0 326 052 and EP 0 547 982 describe methods for manufacturing a dispenser body with a metal pocket consisting of a rigid housing and a flexible pocket, in which a seal is connected at their open ends cylindrical pocket blank and a cylindrical housing blank, these two parts are conified simultaneously and then an edge is produced by rolling outwards said connected open ends.

The boxes are conventionally produced by impact spinning, possibly followed by drawing. DE 44 13 331 and US 4,562,942 suggest making the boxes by stamping or stamping-drawing. The known pockets are produced by impact spinning. US 4,562,942 suggests another method of shaping the pocket by showing in FIG. 1 a shallow plunger pocket resembling a food tray obtained by pressing and pleating, but such a pocket, fixed using a ring internal elastic, does not constitute a sufficiently tight separation between the product and the propellant due to the pleated wall in contact with the internal wall of the housing.

PROBLEM

The pocket, whatever it may be, must be able to deform under the effect of the pressure of the propellant gas. It must occupy a volume which decreases progressively with the consumption of the product. Its surface, constituting the separation between the gas and the conditioned product, necessarily decreases during the consumption of the product and, the elasticity of the metal being limited, there is the formation of folds. The pocket is said to be crumplable in the sense that the folds are formed by elastic buckling without breaking the wall. To promote a regular and complete distribution of the product, it is preferable that the main folds, which form when the bag is empty, orient themselves in an orderly fashion. There are many documents which recommend particular forms of pocket allowing to control this formation of folds by pre-orienting them.

In addition, the pocket must be deformed so that there is no collapse, that is to say a centripetal collapse of the wall which results in the formation of a knot trapping the product in the bottom of the pocket and preventing any movement of said product towards the valve.

Pockets such as the one disclosed in EP 0 547 982 are resistant to collapse, but it can be seen that some of them tear at the end of use of the aerosol can. The tear is particularly harmful since it causes the phenomenon that one wanted to avoid: the mixing of the propellant gas with the residual product.

The present invention makes it possible to solve this problem and therefore to obtain a distributor body distributing under pressure liquid to pasty products, with a metallic or metalloplastic pocket which resists collapse well and does not tear during the consumption of the packaged product. .

OBJECT OF THE INVENTION

The product according to the invention is a pocket dispenser body consisting of a rigid metal case containing a crumpled metal or metalloplastic pocket, fixed in a sealed manner on the dispenser and having a substantially vertical smooth wall whose thickness is close to that of the bottom. Such a pocket, typically having a wall of constant uniform thickness less than 150 μm, preferably close to 80 μm, and a bottom almost as thin (thickness ratio typically less than 1.5, preferably 1, 2) can advantageously be carried out by stamping-stretching. Thus produced, it is subjected to annealing which makes it possible to obtain a homogeneous fine-grain metallurgical structure at any point in the ladle.

Until now, the pockets have been produced by impact spinning, using the techniques and facilities provided for the cases. However, the pocket having to have a thin wall, the spinning ratio is such that it is impossible, with the machines and tools currently used, to produce pockets having bottoms of the same thickness as the vertical wall. Typically, the bottom of an impact spun pocket keeps a thickness close to 0.4 mm when the wall locally reaches a thickness close to 0.2 mm. This has the effect of making the bottom much more rigid than the wall and of locating the deformation of the pocket at the junction of the cylindrical wall and the bottom, making this part more fragile than the rest of the pocket and liable to break more easily. at the end of use of the packaged product.

Stamping-stretching is a process that makes it possible to produce hollow bodies of very small thickness such as beverage cans or overcap capsules. No doubt because of the severe regulations governing the conditions of use of aerosol cans operating under pressure, also due to the quantities to be produced to reach an acceptable break-even point, no aerosol can producer has considered until 'now to produce stamped-drawn housings. This process is therefore poorly understood by manufacturers of aerosol cans of aluminum alloy, accustomed to the spinning by impact of thick pions. He asks for a bet At the meticulous point of tools which is only justified for very large quantities.

The Applicant has, however, used this process, not to produce the rigid housing but to produce the pockets. The advantage of stamping and drawing lies in the fact that by this process, a better uniformity is easily obtained between the thickness of the bottom and the thickness of the vertical wall. On the other hand, the metallurgical structure of the product obtained is more favorable, both vis-à-vis the tear resistance than vis-à-vis the ability to further shaping.

This process consists of transforming by stamping and then drawing a blank blank cut from a metal strip (aluminum, aluminum alloy, tin, etc.) or into a metalloplastic complex, comprising at least one metallic layer and one thermoplastic layer (by polyolefin, polyester (PET), etc.). After cutting the blank, a cylindrical blank is formed by stamping, the skirt of which is then subjected to a certain number of drawing passes.

To obtain the pocket, the number of drawing passes is defined as a function of the wall thickness of the strip and of the desired taper. The pocket can indeed be cylindrical but, for handling reasons, it advantageously has a frustoconical shape, which makes it easily stackable. The capsule obtained after the stretching passes comprises a stepped succession of cylindrical skirts and is then compressed between a punch and a frustoconical matrix, so as to obtain a frustoconical pocket.

The stamped-stretched pocket thus obtained has a much more uniform thickness, the thickness of the bottom being able to be much closer to that of the vertical wall. Typically, for a vertical wall with a thickness of the order of 0.1 mm, the drawing-drawing makes it possible to have a bottom of substantially identical thickness while the impact spinning leaves the bottom a thickness greater than 0, 25 mm.

The bottom of the stamped-stretched pocket can be almost as thin, therefore as flexible as its vertical wall. The Applicant has found that as long as the thickness of the bottom remains less than twice the thickness of the wall located near the bottom, there is no localization of the deformation at the junction of the wall and the bottom when the bag empties of its contents during the distribution of the product. The risk of rupture at this location - therefore of contact between the propellant and the conditioned product - is much lower as soon as the thickness of the bottom is less than twice the thickness of the vertical wall. We can thus target significantly smaller thicknesses (a vertical wall about one tenth of a millimeter thick). Preferably, it will be sought that the thickness of the bottom does not exceed 1.5, or better still 1.2 times the thickness of the vertical wall.

We may also wish to obtain a thicker wall at the open end of the pocket, so as to avoid the formation of folds when the latter is shrunk together with a housing blank, according to one of the methods described in FR 2 140 804, EP 0 326 052 or EP-A-0 547 982. This is possible by playing on the choice of drawing rings and the profiles of the punches.

Stamping-stretching also offers the advantage of obtaining a constant wall thickness of the pockets over the entire circumference to within 5 μm, while that of the wall of the pockets obtained hitherto by impact spinning varies in proportion almost ten times higher. This results in a much more regular deformation of the pocket when it empties of its content. This deformation better respects the pocket's symmetry of revolution and removes the risk of buckling or collapse during the distribution of the product.

Depending on the use to be made of the pocket, the stamped-drawn blank from which the pocket will be produced has a variable height:

- The pocket can be a "classic" pocket. In this case, it must occupy the largest possible volume and its height is close to that of the rigid case intended to contain it (typically 90 to 250 mm, depending on the diameter of the case)

- The pocket can also be used as a plunger pocket. In this case, it is fixed approximately halfway up the rigid case, separating the product to be dispensed located in the upper part of the case and the propellant, located in the lower part of the case. As the product is used, the pocket is pushed upwards under the effect of the propellant gas pressure and turns like a sock to gradually occupy the upper volume of the case. The height of the pocket used as a piston pocket is close to half the height of the rigid case intended to contain it.

Preferably, by giving a shape adapted to the punches of the last stretching passes, the shape of the bottom intended for the pocket is produced directly on the stamped-stretched part. For a "classic" pocket, the shape of the bottom does not matter. By cons for bags - pistons, the hollow shape of the bottom (concave bottom, entering the volume occupied by the product) is preferred because it promotes a gradual, non-abrupt reversal of the bag during the distribution of the packaged product.

Preferably, the pocket has a slightly frustoconical shape. This facilitates the handling of pockets stacked on top of each other in large quantities. Overall, this stamped-stretched pocket looks like an overcap, like the one used on Champagne or wine bottles.

The taper of the pocket is defined by the ratio (Dl - D2) / H where Dl is the diameter of the open end, D2 is the diameter of the bottom and H the height of the part. We are targeting a taper close to 1/30, which corresponds to a standard of overcapping capsule obtained by stamping-stretching.

The diameter of the open end of the pocket corresponds to the diameter of the part of the housing or of the housing blank to which the pocket will be secured. In practice, if the bag is secured to the already conical casing (process described in EP 0 01 7 147), this diameter is close to one inch (25.4 mm), the standard value for the orifices of the aerosol cans on the edge of which a valve cup (also of standard size) is crimped. The diameter of the bottom of the pocket is defined as a function of the pocket height and the taper chosen.

On the other hand, if the pocket is secured to a blank of the housing before joint conformation of the two blanks (methods described in FR 2 140 804, EP 0 326 052 and EP A 0 547 982), the diameter of the open end of the pocket will be close to the inside diameter of the case.

It is also possible to form the pocket independently of the housing, either before its introduction into the housing blank or after introduction and fixing to the already conified housing. In the first case, the pocket is shaped after stamping-stretching its blank by placing it on a forming mandrel having the desired shape of the neck then by deforming the wall of the blank using a capsulator with pockets or jaws which are pressed against the mandrel. Then we put the bag in the housing blank, the housing is conified and then the pocket is fixed to the housing according to one of the existing methods, such as those described in FR 2 310 287 or EP 0 755 877. In the second case, the stamped pocket blank stretched on the rolled edge of the already conical casing, then an internal pressure, typically between 5 and 20 atmospheres, is put, said thin pocket blank which swells under the effect of pressure until it meets the enclosure wall. The particular metallurgical structure obtained by stamping-drawing gives the pocket blank significant malleability which allows it to be shaped without risk of rupture inside the housing.

The metal of the pockets obtained according to the invention by stamping-drawing is advantageously made of a particularly ductile aluminum alloy, that is to say of which the elongation at break A% is greater than 12%. It is possible, for example, to choose an alloy usually used for making overcap capsules, that is to say a low alloy alloy of the 1000 series (in particular 1050, 1070, 1100, or 1200), or the alloy 3003, or the 801 1 alloy according to the standardized designation of the Aluminum Association.

The rigid housing can be produced according to any known process: spinning, drawing-drawing, but also stamping-drawing or rolling, welding and assembly. By making the housing by impact spinning, possibly followed by drawing, a low alloy aluminum alloy, of the 1070 type, is generally used or, preferably, an alloy having as good ductility but having better mechanical characteristics, such as than the aluminum alloy with low copper and manganese content presented by the applicant in French patent application FR 98 00869. The pocket blank - part with a frustoconical skirt - is then heat treated for a time and at a chosen temperature so as to remove the lubricant (introduced at at least one of the stages of drawing - drawing) present on the surface of the capsule and to obtain a metallurgical structure in the annealed state. One then observes in the thickness of the thin wall of the pocket a crystallographic structure recrystallized with fine grains, the average diameter of which is generally close to 10 μm and in no place exceeds 80 μm. Such a structure is much more favorable than that obtained by impact spinning, where the grains have roughly recrystallized, their average diameter possibly locally exceeding 200 μm. The metallurgical structure resulting from impact spinning is thus more fragile and deforms in a less homogeneous manner, making the ladle more sensitive to collapse and rupture.

The pocket can also be produced from a metalloplastic complex composed of at least one metallic layer and one thermoplastic polymeric layer. The structures are of the M / P, P / M / P or M / P / M type, where M denotes a metallic layer and P denotes a plastic layer, the layers being adherent to each other, possibly using 'an adhesive layer. To be easily stampable-stretchable, the metalloplastic strip preferably comprises more than 50% of metal by volume. The metal is preferably chosen from the group formed by aluminum, aluminum alloys. The polymeric material is preferably chosen from the group formed by polyolefins (polyethylenes, polypropylenes) - obtained in particular by metallocene catalysis when it is desired to improve their adhesive properties - and polyesters such as PET (polyethylene terephthalate).

In the M / P structure, the plastic layer is preferably located on the outside surface of the bag. The P / M / P structure is preferred when the conditioned product is aggressive towards metal. Finally, the M / P / M structure is an impermeable, tear-proof and remarkably flexible structure. By reducing the proportion of metal in the latter structure, a higher level of overall flexibility is obtained, which promotes the orderly formation of folds.

If a metalloplastic pocket is generally more difficult to shape, its use makes the subsequent steps of the process easier since the joining of the pocket and the housing, described below, is greatly facilitated.

Whether it is a "classic" pocket or a plunger pocket, the pocket must resist collapse and the main folds that form when the pocket empties must orient themselves in an orderly fashion. To this end, some longitudinal grooves are preferably produced on the wall of a "conventional" pocket and circumferential grooves on the wall of the piston pocket, the latter causing concentric rings, or rods, which stiffen the piston pocket and promote its vertical mobility.

The technique used on the capsules is used to make these grooves: the pocket is threaded onto a forming mandrel having the grooves to be formed on the pocket hollow, and the conical wall is deformed using a pocket or jaws, so that they press against the mandrel. The bag is then removed from the mandrel using a valve or a pull tab or by blowing in compressed air.

Several forms of grooves promote the formation of orderly folds and are effective against the risk of collapse. As regards conventional pockets, one can for example choose the longitudinal grooves described in US 3,979,025. If the pocket is intended to be placed on an already conical casing, it is recommended to preform, using an expandable mandrel and a ring of elastomeric polymeric material, its open end so that a flared edge can come to bear on the rolled edge of the rigid case as indicated in EP 0 017 147.

If the pocket is in fact a blank intended to be shrunk together with the housing blank (methods described in FR 2 140 804, EP 0 326 052 and EP 0 547 982), there is no particular shaping of the frustoconical pocket other than the formation of the grooves but it is preferable to choose it thicker at its open end to avoid the formation of folds during the shrinking.

If it is a plunger pocket, it should preferably have a bottom and a wall near the bottom typically thinner than the wall at the top, near the open end intended to be fixed on the wall of the rigid housing. This prevents a lateral collapse from occurring before the plunger pocket begins to turn.

The watertight assembly of the metal bag and the rigid case is achieved by a cylindrical annular junction which is obtained either by chemical means, typically a thin adhesive layer - at most a few tenths of a millimeter thick - or by mechanical means such as force fitting.

When an adhesive layer is used, the adhesive can be chosen from solutions or dispersions of resins, according to the case in aqueous medium or in solvent medium, based on EAA (ethylene-acrylic acid copolymer), EVA (ethylene copolymer - vinyl acetate), VMCH (terpolymer chloride vinyl - vinyl acetate - maleic acid), SURLYN (R) ionomer resin, or based on hot-melt resins, known as "hot-melt". Preferably, an adhesive containing VMCH is used, for example the mixture cyclohexanone (-69%), VMCH (-30%) and di-octyl phthalate (DOP, -1%) which seems particularly well suited.

When the pocket is made of a metalloplastic complex, the waterproof connection pocket - case can be done by a simple heat seal, by melting the outer plastic layer of the pocket either in contact with the interior varnish of the case or directly on the metal naked, the presence of a varnish is not essential since the interior of the rigid case is not in contact with the packaged product. In the latter case, the outer plastic layer of the metalloplastic is for example a grafted polypropylene or else a polyolefin obtained by metallocene catalysis.

To obtain a tight assembly of the bag with the already confined casing, bonding is preferably carried out with the mixture cyclohexanone (-69%), VMCH (-30%) and di-octyl phthalate (DOP, -1%), which after drying serves as a sealing medium. The pocket aerosol can thus obtained can be delivered to the conditioner which fills the pocket with the product to be dispensed and crimps a valve cup on the neck, after having introduced a seal. The pressurization of the lower volume is carried out by injecting the propellant gas through a hole made in the middle of the bottom and then plugged for example using a strand or a Nicholson nozzle.

When the bag is to be joined by gluing to the blank of the case which has not yet been confined (according to one of the methods described in FR 2 140 804, EP 0 326 052 or EP 0 547 982), the adhesive is deposited. by roller on the internal cylindrical wall of the housing blank and / or on the external wall of the pocket, over a height which corresponds at least to the part intended to be shrinking during conification. One carries out the common conification of the pocket and the blank of housing then one carries out a rolled edge. The pocket case thus obtained is then delivered to the conditioner.

When the pocket is formed independently of the housing, either before its introduction into the blank of the housing or after its introduction into the housing, it is desirable to make the junction between the flared edge of the pocket and the rolled edge of the housing in interposing an attached elastic seal, such as that referenced 3 in FR 2 310 287. It is also possible to replace this elastic seal with a thermofusible thermoplastic layer deposited by roller on the neck of the pocket.

When it is a question of joining a plunger pocket to the blank of the casing which is not yet conified, the glue is deposited with a roller on the internal cylindrical wall of the blank of the casing and / or on the outside of the pocket, over at least ten millimeters then the piston pocket is placed on a conical mandrel whose upper part, which has the largest diameter, has an expandable part to ensure the compression of the glue or adhesive between pocket and case. In order to avoid deformations, the wall of the rigid housing is maintained externally using a metal ring, preferably made up of several radially segmented sectors, the internal diameter of which is equal to the external diameter of the housing.

EMBODIMENT OF THE INVENTION - EXAMPLE

The method according to the invention will be better understood from the detailed description of the embodiment of an aerosol can with a particular pocket, described here by way of nonlimiting example.

Figure 1 is a schematic view in vertical section of a pocket obtained by stamping - stretching

Figure 2 is a schematic view in vertical section of the blank obtained after joining by gluing at their open ends of the pocket of Figure 1 with the blank of the rigid housing.

FIG. 3 is a schematic view in vertical section of the pocket case obtained after conformation and rolling of the edge of the assembly of FIG. 2.

Figure 4 is a schematic view in vertical section of the blank obtained after joining by gluing a plunger pocket with a rigid housing blank.

FIG. 5 is a schematic view in vertical section of the piston pocket housing obtained after conformation and rolling of the edge of the assembly of FIG. 4.

EXAMPLE 1 (Figures 1 to 3)

In this example, this involves producing a 40 mm diameter pocket aerosol can, 170 mm high.

In order to contain the maximum amount of product, the pocket 1 of this example, illustrated in FIG. 1, has a height of 163 mm, almost equal to that of the rigid case. After bonding to the interior wall of the housing, it is conified together with the rigid housing according to the method described in EP 0 547 982.

After stamping-stretching, the pocket 1 is in the form of a frustoconical capsule with a convex or flat bottom 2, of appearance substantially similar to that of a capsule for a bottle of Champagne. The thickness of the frustoconical wall 3 is 0.10 mm, that of the bottom 2 is 0.12 mm.

The diameter of the open end of the pocket is substantially equal to the inside diameter of the blank of the case (39.2 mm).

The conicity of the capsule is defined by the ratio (D l - D2) / H where Dl is the diameter of the open end 4, D2 is the diameter of the bottom 2, at the junction between the bottom 2 and the frustoconical wall 3 and H is the height of the room. In order to obtain a taper of 1/30, the diameter of the bottom 2 has approximately 34 mm.

After threading on a forming mandrel then passage to the pocket or jaw capsulator, the pocket 1 has longitudinal grooves on its frustoconical wall.

The pocket 1 is then brought by translation into the interior of the housing blank 11 which is already fixed to the assembly turret and has already been coated with glue. The glue used is a cyclohexanone mixture (-69%), VMCH (-30%) and di-octyl phthalate (DOP, -1%). It is deposited by roller on the internal wall of the housing blank 11 over a height equivalent to the part 16 which will be constricted during conification. It is possible, but not necessary, to also deposit it in the part 15 which will be rolled by dabbing to produce the rolled edge 25 on which the valve cup is crimped. When the open end 4 of the pocket arrives at the open end 14 of the housing blank 11, the translational movement stops and the feed mandrel of the pocket is withdrawn. After a short waiting time (5 to 25 hundredths of a second, depending on the production rate), the pocket 1 and the housing blank 11 are entrusted jointly. Finally a rolled edge 25 is obtained by stamping.

In order to avoid the formation of folds during the joint conformation of the housing and the pocket, the upper part 6 of the pocket has a thickness of 0.2 mm. This is sufficient because the glue which secures the pocket and the case transmits part of the stiffness of the case to the pocket.

Since the pocket 1 is deformed only at its open end 4, the thicknesses of the bottom 26 and of the wall 27 remain identical to the initial thicknesses of the bottom 2 and of the substantially vertical wall 3 of the stamped-drawn part.

EXAMPLE 2 (Figures 4 and 5)

In this example, this involves producing an aerosol can with a 40 mm diameter piston pocket and a height of 176 mm.

The pocket 31 of this example, illustrated in FIG. 4, has a height of 100 mm, slightly greater than half that of the rigid case. She is stuck on the inner wall of the housing, over an area 46 approximately 10 mm wide and approximately 130 mm distant from the bottom of the housing 42.

After stamping-stretching, the pocket 31 is in the form of a frustoconical capsule with a hollow bottom 32. The thickness of the frustoconical wall 33 is 0.1 mm, that of the bottom 2 is 0.12 mm. The diameter of the open end of the pocket is substantially equal to the inside diameter of the blank of the case (39.2 mm). The conicity of the capsule is here also equal to 1/30.

For the plunger bag to function properly, the bottom and the wall near the bottom must be typically thinner than the upper wall, near the bonding zone 46, which prevents a lateral collapse from occurring. occur before the beginning of the inversion of the pocket. Here the thickness of the wall at the level of the bonding zone 46 is close to fifteen hundredths of a millimeter.

Concentric rings 48, or rods, are produced on the vertical wall of the pocket. They circumferentially stiffen the pocket and promote its vertical mobility.

The pocket 31 is then brought by translation into the interior of the housing blank 41 which is already fixed on the assembly turret and has already been coated with glue at the level of the zone 46 spaced 130 mm from the bottom of the housing 42. The adhesive used is a mixture of cyclohexanone (-69%), VMCH (-30%) and di-octyl phthalate (DOP, -1%).

When the open end 34 of the pocket arrives at the area 46 of the housing blank 41, the translational movement stops and the feed mandrel of the pocket is withdrawn. After a short waiting time, the end open of the housing blank 41 is conical. Finally a rolled edge 55 is obtained by stamping.

ADVANTAGES OF THE PROCESS ACCORDING TO THE INVENTION

• Very low risk of propellant leaking into the product throughout the life of the aerosol.

• Reduced risk of collapse due to the circumferential homogeneity of the thickness

• No risk of propellant gas migrating through the pocket

Claims

1. Pocket dispenser body (21; 51) consisting of a rigid metal casing (22; 52) containing a crumplable metallic or metalloplastic pocket (1; 31), tightly fixed to the rigid casing (22, 52) and having a substantially vertical wall (27, 33) smooth whose thickness is close to that of the bottom (26, 32).

2. pocket distributor body (21; 51) according to claim 1, characterized in that the ratio between the thickness of the bottom (26, 32) of the pocket (1, 31) and the thickness of the wall substantially vertical (27, 33) of said pocket (1, 31) is less than 2.

3. Pocket dispenser body (21; 51) according to claim 1 or 2, characterized in that the thickness of the substantially vertical wall (27, 33) of the pocket (1, 31) is less than 150 microns.

4. Pocket dispenser body (21; 51) according to any one of claims 1 to 3, characterized in that said pocket (1; 31) is produced by stamping-stretching.

5. Pocket dispenser body according to any one of claims 1 to 4, characterized in that said pocket (1; 31) is made from a strip of an aluminum alloy belonging to the group comprising 1050 alloys , 1070, 1100, 1200 and 801 1.

6. pocket dispenser body according to any one of claims 1 to 5, characterized in that said pocket (1; 31) is made from a strip of a metalloplastic complex, composed at least of a metal layer and a thermoplastic polymeric layer.

7. Pocket dispenser body according to any one of claims 1 to 6, characterized in that said sealed assembly of the housing (1 1; 41) with a flexible pocket (1; 31) is produced by gluing using an adhesive containing a mixture of cyclohexanone, maleic modified vinyl acetochloride (VMCH) and di-octyl phthalate (DOP).

8. Pocket dispenser body according to any one of claims 1 to 7, characterized in that said sealed assembly of the housing (1 1; 41) with a flexible pocket (1; 31) is produced by welding and / or by deformation.

9. Pocket dispenser body according to any one of claims 1 to 7, characterized in that said sealed assembly of the housing (1 1; 41) with a flexible pocket (1; 31) is produced by interposing an elastic seal between the rolled edge of the case and the edge of the pocket.

10. Pocket distributor body according to claim 6, characterized in that said sealed assembly of the housing (1 1; 41) with a flexible bag (1; 31) is produced by heat sealing.

1 1. Pocket dispenser body according to any one of Claims 1 to 10, characterized in that the pocket is provided with grooves in order to improve the resistance of the pocket to collapse and the pre-orientation of the main folds.

12. Pocket dispenser body according to any one of claims 1 to 1 1, characterized in that the pocket is thicker in the vicinity of its open end and in that it is conified together with the housing blank.

13. Pocket dispenser body according to any one of claims 1 to 1 1, characterized in that the pocket is flared in the vicinity of its open end, then introduced into the rigid housing and glued to the rolled edge of the housing.

14. Pocket dispenser body according to any one of claims 1 to 1 1, characterized in that the pressed-drawn pocket is glued at mid-height of the blank of the rigid housing to a height of about 10 mm.

15. Pocket dispenser body according to claim 14, characterized in that said pocket has concentric rings and in that its bottom is concave.

1 6. Pocket (1, 31) intended to cooperate with the rigid housing (22, 52) of the distributor body (21, 51) according to any one of claims 1 to 15, characterized in that the substantially vertical wall ( 27, 33) of said pocket is smooth, free of folds and has a thickness substantially equal to that of the bottom (26, 32) of said pocket.