EP0755877A1 - Dual compartment receptacle with tapered inner receptacle - Google Patents

Abstract

The device has a metal outer container, and a compressible internal metal container. The internal container is formed independently of the outer container, and is esp. decreased in size, so that the diameter of its aperture corresponds to the outer container aperture, which is to be sealed by a valve. The internal container is positioned in the outer one, so that this can be processed further, esp. a base, and/or cover, or shoulder, can be formed, without deforming the internal container. The containers are connected after these stages.

Description

The present invention relates to a method for producing a two-chamber container for a pressure valve can, as is used for dispensing flowable products, in particular solvent-containing or cosmetic fluids, with a one-part or multi-part, metallic outer container and a compressible metallic inner container, and one Two-chamber containers manufactured by this method and their use in pressure valve cans.

Such two-chamber containers are used today in approximately 2% of the approximately 6 billion spray cans sold worldwide and have proven particularly useful for storing and dispensing a wide variety of products. Cans in which the blowing agent is separated from the filling material, hereinafter referred to as two-chamber cans, are of increasing importance. On the one hand, because with such two-chamber cans the generally used and flammable propellant gas, e.g. butane, propane, etc., is retained in the two-chamber container and can thus be disposed of, on the other hand, such cans also allow compressed gases, in particular air, nitrogen, carbon dioxide, etc. to be used, which would chemically change the filled products if they came into contact with the contents.

Metallic containers, in particular made of aluminum, are particularly suitable for the production of such two-chamber cans and are known, for example, from DE-38'08'438 or EP-17'147. These two-chamber boxes are either multi-part, ie made up of a rigid cylindrical jacket part, a bottom part, a container lid (dome) and a soft, metallic inner container, or two-part, ie made up of a one-piece and butted outer container and a soft, metallic inner container. There are various difficulties with this type of cans. So at the use of different metals, e.g. tinplate in combination with aluminum, undesired bimetal effects occur at the connection points and special measures are therefore necessary. In other cases, the adhesives used are not universally suitable for every filling material and an additional protective covering must be provided. Last but not least, welding or other metallic connection processes can lead to undesirable deformations and weak points in the container parts, which are made as thin as possible, which do not meet the high requirements for pressure safety.

Small containers are therefore also known in which a cylindrical inner container is pushed from above into a cylindrical outer container. These containers are sealed with conventional valves and therefore have an internal diameter of approximately 25.4 mm (1 inch). With this construction, containers with a capacity of 15 - 70 ml can be realized, however this construction is not suitable for the provision of commercially available pressure valve cans with a capacity of usually 70 - 250 ml or more, because the space provided for the propellant between outer container and inner container may not exceed 40% of the outer container volume, depending on the country-specific legal regulations. For example, with a cylindrical inner container with a filling volume of 80 ml, which is inserted into the container opening of 1 inch diameter, which can be closed with a conventional valve, of a 40 * 170.5 mm, butted outer container with 175 ml content, a ratio of 45:55 at best for filling volume to reach intermediate volume. The just approved ratio of 60:40 cannot be achieved with this design.

From this prior art it is clear that the known methods for the pressure-tight attachment of the metallic inner container to the outer container are either technically complex (gluing and coating), lead to insufficiently reliable cans (weak points) or not for large-sized or. A sufficient volume of cans (waste of material, mock packs) are suitable.

It is therefore an object of the present invention, a universally usable, double-walled can body resp. To create two-chamber containers that can be manufactured in a technically simple and cost-effective manner and that are reliable even with cans with a large filling volume.

This object is achieved by a surprisingly simple method with the features of claim 1 and a container produced by this method. The method according to the invention for producing such a double-walled container is essentially characterized in that a preformed, i.e. essentially an inner container tapering towards the container opening is inserted and fastened to the outer container. In a preferred development, the collapsible inner container is preformed in such a way that it is frictionally connected to the outer container in the area of a contact surface.

In a first embodiment of the manufacturing process, the inner container is tapered independently of the outer container in a first process step and, in the case of a one-piece outer container, is inserted into the essentially cylindrical outer container in a further process step and positioned so that it does not during the further shaping processing of the outer container is deformed. On the one hand, this is achieved by suitable dimensioning and shaping of the inner container and on the other hand also made possible by a special positioning of the same in the outer container. After the outer container has been deformed, the inner container is pushed into its end position and then connected to the outer container.

In a preferred embodiment, the inner container has a cylindrical neck section which is inserted into a likewise cylindrical neck part of the outer container. For mutual attachment, the opening edge of the outer container is flanged inwards so that an annular groove opens inwards, into which the opening edge of the preformed inner container can be inserted and further rolled together with the groove-shaped flanging of the outer container. The opening edge of the inner container is preferably deformed inward in order to create an annular surface which nestles into the groove-shaped flanging.

In another embodiment, the neck section of the inner container is dimensioned and shaped in such a way that its opening edge in the end position of the insertion process projects beyond the edge of the outer container that is rolled inwards or outwards. In a further method step, this part of the inner container which projects beyond the outer container is placed over the rolled edge of the outer container. Alternatively, in this embodiment, the inner container can have a particularly shaped area which, when in contact with the outer container, determines the end position of the inner container.

In a further development, the cylindrical neck section of the inner container lies frictionally in the cylindrical neck part of the outer container. Basically, each part of the inner or outer container can be in frictional contact with the other container and the inner and outer containers in a fixed position to each other hold, ie make special holding devices superfluous. In addition, the bonding or. Sealing area under the neck area to be subsequently deformed, in particular to be clinched.

In a further embodiment of the manufacturing method according to the invention, a multi-part outer container is used, the bottom part or lid part (dome) of which is not yet attached to the jacket part. The inner container is in turn deformed independently of the outer container and then inserted into the jacket part. The inner container can be pushed in at the bottom until the opening edge of the tapered inner container lies in the outer container opening in order to be subsequently fastened there. If, for example, the outer container has an opening edge that is flanged outwards, the inner container is designed such that it protrudes through this opening edge and can be placed over this opening edge after a suitable deformation. In the other case, the inner container is inserted into the cover part of the outer container on the cover side, the cover part is attached to the cover part without deforming the inner container, and the inner container is attached to the cover part opening if it has not already been attached to the cover part before the insertion process. The edge can in turn be rolled inwards or outwards. An additional pressure-proof fastening or sealing can be carried out before the joint rolling in or in a further process step.

The advantages of this design are immediately apparent to the person skilled in the art and can be seen in the surprisingly simple technical production process for double-walled can bodies, which make it possible to produce reliable two-chamber pressure cans even for filling volumes of over 70 ml.

Another advantage can be seen in the fact that the space provided for the propellant can be kept as small as necessary and thus the can material required for the outer container can be minimized.

• Fig. 1a und 1b: schematische Darstellungen von Zweikammerbehältern bekannter Art;
• Fig. 2a und 2b: schematische Darstellung des erfindungsgemässen Verfahrens zur Herstellung eines Zweikammerbehälters;
• Fig. 3a und 3b: schematische Darstellung eines erfindungsgemässen Zweikammerbehälters;
• Figur 1a zeigt einen Zweikammerbehälter bekannter Art mit einem zweiteiligen Aussenbehälter 2. Dieser umfasst einen im wesentlichen zylindrischen Behälterkörper 3 und einen darauf aufgesetzten Deckelteil (Domteil). In den Behälterkörper 3 des Aussenbehälters ist ein Innenbehälter 5 eingelegt. Innenbehälter 5, Behälterkörper 3 und Deckelteil (nicht dargestellt) sind in einer Verbindungszone 6 miteinander verbunden. Zur Begasung des Zwischenraumes 8 zwischen Innenbehälter 5 und Aussenbehälter 2 ist im Bodenteil des Behälterkörpers 3 eine Begasungsöffnung 9 vorgesehen, welche mit einem elastischen Stopfen druckdicht verschlossen werden kann. Zur Abdichtung des für das Treibgas vorgesehenen Zwischenraumes ist im Bereich der Verbindungszone 6 ein Haft- und Dichtungsmittel 11 vorgesehen. Bei diesem Ausführungsbeispiel weist der Aussenbehälter 2 ein Gesamtvolumen von 171 ml auf, wobei der Innenbehälter 5 bei der Verwendung von Flüssiggas als Treibmittel ein Volumen von ca. 120 ml aufweist. Bei der Verwendung von komprimiertem Gas als Treibmittel, beispielsweise Luft, muss das Füllgutvolumen weiter reduziert werden.
• Der in Figur 1b dargestellte Zweikammerbehälter weist einen einteiligen Aussenbehälter 2 mit einem konifizierten Schulterbereich 12 auf. Der Durchmesser der Aussenbehälteröffnung 13 entspricht dem Durchmesser eines für den Verschluss des Zweikammerbehälters vorgesehenen Ventilteils. In diesen Aussenbehälter 2 ist ein Innenbehälter 5 eingeschoben, dessen Öffungsrand auf dem Öffnungsrand 13 des Aussenbehälters 2 aufliegt. Mit dieser Konstruktion lassen sich nur Doppelbehälter anfertigen, bei denen sich der Durchmesser des Aussenbehälters 2 und der Durchmesser des Innenbehälters 5 resp. Durchmesser des vorgesehenen Ventilteils nicht wesentlich voneinander unterscheiden, um das Zwischenvolumen innerhalb der gesetzlichen Vorschriften halten zu können. In der dargestellten Ausführungsform weist der Innenbehälter ein Volumen von ca. 80 ml auf, während das Gesamtvolumen des Aussenbehälters 175 ml beträgt. Damit beträgt das Verhältnis zwischen Füllgutvolumen und Treibmittelvolumen 80:95, statt höchstens 60:40.
• In Figur 2a ist ein erfindungsgemässes Verfahren schematisch dargestellt. Dabei wird der Innenbehälter 5 in einem ersten Verfahrensschritt unabhängig vom Aussenbehälter 2 vorgeformt, insbesondere verjüngt, wobei der Durchmesser der Innenbehälteröffung 14 dem Durchmesser der mit einem Ventilteil verschliessbaren Aussenbehälteröffnung 13 angepasst wird. In einer bevorzugten Ausführungsform weist der Rand der Innenbehälteröffung 14 eine nach innen gerichtete Stossfläche 15 auf. In einem zweiten Verfahrensschritt wird der derart vorgeformte Innenbehälter in den zylindrischen Mantelteil 3 des Aussenbehälters 2 eingeführt und am Bodenteil des Aussenbehälters festgehalten. Dies kann pneumatisch über das Bodenloch 9 geschehen. Hilfsweise kann an den Innenbehälter 5 eine Kontaktzone 16 angeformt sein, welche mit dem Aussenbehälter 2 eine reibschlüssige Verbindung eingeht. Die Formung des in der Regel weichgeglühten und dünnen Innenbehälters 5 kann mit allen geeigneten Verfahren und insbesondere mit der in der Metallverarbeitung bekannten Drück- oder Einziehtechnik vorgenommen werden. In einem nächsten Verfahrensschritt wird der Aussenbehälter 2 weiter bearbeitet. Diese weitere Bearbeitung hängt von dem Aufbau des Aussenbehälters ab, d.h. sieht bei einem einteiligen Aussenbehälter 2 die Formung einer Dosenschulter 12 vor, resp. umfasst das Aufbringen eines Boden- und/oder Deckelteils im Falle eines mehrteiligen Aussenbehälters. Vorzugsweise weist der Öffnungsrand des einteiligen Aussenbehälters 2 eine nach innen gerichtete, nutförmige Bördelung 17 auf. Im folgenden Verfahrensschritt wird der vorgeformte Innenbehälter 5 in den vorbereiteten Aussenbehälter 2 geschoben, derart, dass der Öffnungsrand des vorgeformten Innenbehälters 5 am Öffnungsrand des Aussenbehälters 2 anliegt. Die derart positionierten Behälter werden in einem oder mehreren Verfahrensschritten einzeln oder gemeinsam nach innen oder nach aussen verformt und dann in einem oder mehreren weiteren Schritten miteinander verbunden. Es versteht sich, dass bei einem mehrteiligen Behälter mit Dom, der vorgeformte Innenbehälter vor dem Einbringen des Innenbehälters in den zylindrischen Mantelteil, dieser zuerst mit dem domförmigen Deckelteil verbunden wird. Es versteht sich auch, dass der Innenbehälter in diesem Fall auch anders dimensioniert werden kann und insbesondere die gleiche Längenausdehnung aufweisen kann, wie der Aussenbehälter. In einem letzten Verfahrensschritt wird durch die Bodenöffnung 9 ein fliessfähiges Haft- und Dichtungsmittel 11 eingebracht.
• Das in Fig. 2b dargestellte Verfahren unterscheidet sich vom eben beschriebenen Verfahren lediglich darin, dass der Aussenbehälter mit einer geschlossenen nach Innen oder Aussen gerichteten Bördelung versehen ist und der Innenbehälter durch die Öffnung des Aussenbehälters hindurchgeschoben wird, um nach einer geeigneten Aufweitung seiner Randpartie auf diese Bördelung aufgelegt wird.
• Die Figuren 3a und 3b zeigen einen nach dem erfindungsgemässen Verfahren hergestellten Zweikammerbehälter, der in einer bevorzugten Ausführungsform ein Füllgutvolumen von ca. 130 ml und ein Aussenbehältervolumen von 175 ml aufweist. Damit lässt sich ein Verhältnis zwischen Produkt und Treibmittel von 70:30 erreichen. Durch den Einsatz verjüngter Innenbehälter können erstmals sowohl 1-teilige als auch mehrteilig Zweikammerbehälter für Druckventil-Dosen mit grossem Füllgutvolumen in gleicher Art und Weise hergestellt werden. Das erfindungsgemässe Verfahren erlaubt erstmals Dosen mit grossem Füllgutvolumen herzustellen, bei denen der Aussendurchmesser unabhängig vom Durchmesser des abschliessenden Ventilteils gewählt werden kann.

The present invention is to be explained in more detail below using an exemplary embodiment and the figures. Show:

• 1a and 1b: schematic representations of two-chamber containers of known type;
• 2a and 2b: schematic representation of the method according to the invention for producing a two-chamber container;
• 3a and 3b: schematic representation of a two-chamber container according to the invention;
• FIG. 1a shows a two-chamber container of known type with a two-part outer container 2. This comprises an essentially cylindrical container body 3 and a cover part (dome part) placed thereon. An inner container 5 is inserted into the container body 3 of the outer container. Inner container 5, container body 3 and cover part (not shown) are connected to one another in a connecting zone 6. For gassing the space 8 between the inner container 5 and outer container 2, a gassing opening 9 is provided in the bottom part of the container body 3, which can be closed pressure-tight with an elastic stopper. To seal the space provided for the propellant gas, an adhesive and sealing means 11 is provided in the area of the connection zone 6. In this exemplary embodiment, the outer container 2 has a total volume of 171 ml, the inner container 5 having a volume of approximately 120 ml when using LPG as the propellant. When using compressed Gas as a blowing agent, such as air, must further reduce the volume of the product.
• The two-chamber container shown in FIG. 1b has a one-piece outer container 2 with a butted shoulder region 12. The diameter of the outer container opening 13 corresponds to the diameter of a valve part provided for closing the two-chamber container. An inner container 5 is inserted into this outer container 2, the opening edge of which lies on the opening edge 13 of the outer container 2. With this construction, only double containers can be made, in which the diameter of the outer container 2 and the diameter of the inner container 5, respectively. Do not differ significantly from each other in the diameter of the intended valve part in order to be able to keep the intermediate volume within the legal regulations. In the embodiment shown, the inner container has a volume of approximately 80 ml, while the total volume of the outer container is 175 ml. The ratio between filling volume and blowing agent volume is therefore 80:95, instead of a maximum of 60:40.
• A method according to the invention is shown schematically in FIG. 2a. In a first method step, the inner container 5 is preformed, in particular tapered, independently of the outer container 2, the diameter of the inner container opening 14 being adapted to the diameter of the outer container opening 13 which can be closed with a valve part. In a preferred embodiment, the edge of the inner container opening 14 has an inwardly directed butting surface 15. In a second method step, the inner container preformed in this way is inserted into the cylindrical jacket part 3 of the outer container 2 and held on the bottom part of the outer container. This can be done pneumatically via the bottom hole 9. Alternatively, a contact zone 16 can be formed on the inner container 5, which enters into a frictional connection with the outer container 2. The shaping of the generally soft annealed and thin inner container 5 can be carried out using any suitable method and in particular using the pressing or drawing technique known in metalworking. In a next step, the outer container 2 is processed further. This further processing depends on the structure of the outer container, ie provides for the formation of a can shoulder 12 in a one-piece outer container 2, respectively. includes the application of a bottom and / or lid part in the case of a multi-part outer container. The opening edge of the one-piece outer container 2 preferably has an inwardly directed, groove-shaped flange 17. In the following method step, the preformed inner container 5 is pushed into the prepared outer container 2 such that the opening edge of the preformed inner container 5 lies against the opening edge of the outer container 2. The containers positioned in this way are individually or jointly deformed inwards or outwards in one or more process steps and then connected to one another in one or more further steps. It goes without saying that in the case of a multi-part container with a dome, the preformed inner container before the inner container is introduced into the cylindrical casing part, this is first connected to the dome-shaped cover part. It is also understood that the inner container can also be dimensioned differently in this case and in particular can have the same length extension as the outer container. In a last method step, a flowable adhesive and sealant 11 is introduced through the bottom opening 9.
• The method shown in Fig. 2b differs from the method just described only in that the outer container is provided with a closed inward or outward flaring and the inner container is pushed through the opening of the outer container is placed on this flanging after a suitable widening of its edge part.
• FIGS. 3a and 3b show a two-chamber container produced by the method according to the invention, which in a preferred embodiment has a filling volume of approximately 130 ml and an outer container volume of 175 ml. This enables a ratio of product to blowing agent of 70:30 to be achieved. By using tapered inner containers, both single-part and multi-part double-chamber containers for pressure valve cans with large contents can be produced in the same way for the first time. The method according to the invention allows for the first time to produce cans with a large filling material volume, in which the outside diameter can be selected independently of the diameter of the closing valve part.

In a special embodiment, it proves to be particularly advantageous that the sealing compound 11 is kept out of the area to be clinched by the frictional contact zone 16.

It goes without saying that all of the materials used for pressure-resistant cans, in particular aluminum or tinplate, can be used for the containers according to the invention, and the inner container can be provided with an inner protective covering, as is customary for the packaging of medicaments, foods or cosmetic products .
Likewise, the bottom part of the inner container can be specially shaped, for example to simplify the manipulation of the inner container through the bottom opening of the outer container or to influence the collapse behavior of the entire inner container. For example, one or more depressions can be provided in the base part, the base part as a whole can converge or be provided with a cone-shaped protuberance.

Claims (19)

Method for producing a two-chamber container for a pressure valve can which can be closed with a valve part, as is used for dispensing flowable products, in particular solvent-containing or cosmetic fluids, which two-chamber container has a one-part or multi-part, metallic outer container and a compressible metallic inner container,
characterized in that the inner container is preformed independently of the outer container and in particular is tapered such that the diameter of the inner container opening corresponds to the diameter of the outer container opening that can be closed with the valve part, that the inner container preformed in this way is introduced into the cylindrical jacket part of the outer container on the opening side or bottom side in such a way that the Inner container is dimensioned and positioned in the outer container so that the outer container can be further processed, in particular the cylindrical jacket part can be provided with a base part and / or a lid part or a can shoulder, without deforming the inner container in such a way that the outer container in the intended manner is processed and that the inner container and the outer container are connected to each other. A method according to claim 1, characterized in that the inner container is pushed into an end position in which the opening edge of the preformed inner container comes to rest in or on the opening edge of the outer container. A method according to claim 1, characterized in that the opening edge of the preformed inner container and the opening edge of the outer container in one or more first steps individually or jointly deformed inwards or outwards and connected to one another in one or more second steps. A method according to claim 1, characterized in that the opening edge of the inner container is deformed in a flange-like manner and this deformation is brought into abutment in an inwardly open flange of the outer container or on an inner or outer flange of the outer container. A method according to claim 1, characterized in that the inner container is frictionally held in the outer container in the region of a contact zone. Method according to one of claims 1-5, characterized in that a flowable adhesive and sealant is introduced between the inner container and outer container and / or an elastic sealant is provided between the opening edge and valve cover for pressure-tight sealing. Application of metal pressing or metal drawing technology for preforming or. for tapering a metallic container, for example an aluminum container, for carrying out the method according to claim 1. Application according to claim 7 to containers made of soft annealed aluminum. Use according to one of claims 7 or 8 on containers with an interior coating. Two-chamber container manufactured by the method according to claim 1, characterized in that the metallic inner container is pre-shaped in such a way that it tapers towards the container opening. Two-chamber container according to claim 10, characterized in that the opening edge of the preformed inner container abuts the opening edge of the outer container and these are connected to one another in a connecting zone. Two-chamber container according to claim 10, characterized in that an area of the inner container abuts the outer container. Two-chamber container according to claim 10, characterized in that the inner container rests frictionally in the region of a contact zone on a counter surface of the outer container. Two-chamber container according to one of claims 10 to 13, characterized in that the inner container consists of soft annealed aluminum. Two-chamber container according to one of claims 10 to 14, characterized in that the inside of the inner container is provided with a protective covering, for example a paint. Two-chamber container according to one of claims 10 to 15, characterized in that the preformed inner container is pressed or drawn in. Two-chamber container according to one of claims 10 to 16, characterized in that an adhesive and sealant, in particular an epoxy-based adhesive and sealant, is provided for the pressure-tight seal between the inner container and the outer container and / or an elastic sealant is inserted between the opening edge and the valve cover . Two-chamber container according to claim 17, characterized in that the area provided with the adhesive and sealing means between the inner container and the outer container lies outside the connection zone. Pressure valve box with a two-chamber container according to one of claims 10 to 18.

Images