EP0687640A1 - Perforated dip tube for double walled pressurized containers - Google Patents

Abstract

The press-out mesh (9) consists of a beaker formed body (11) with several slotted openings (15). A mouth piece (12) has an area (13) for attachment of the inner bag (6) on the mesh, as well as a collar (14) for attachment of the mesh on the container (1). The hook section is formed directly on the valve (3) or on the valve disc (4). The volume of the mesh accrues from the viscosity of the filling medium and the permissible filling pressure. <IMAGE>

Description

The present invention relates to an extrusion grid for an inner bag of a double-walled container, preferably a pressure container with a valve, such as is used for dispensing flowable products, in particular cosmetic and technical fluids, and an inner bag with such an extrusion grid and its use in pressure-resistant containers, in particular Pressure cans, bottles and other dispensers.

Double-walled containers, such as are suitable for the use of the squeeze-out grid according to the invention, are preferably found in the food and material industry, which increasingly offers their viscous, pasty and / or gel-like products in these packages.

With these types of packaging, the contents are stored in collapsible inner containers that are not visible to the consumer. These inner containers can consist, for example, of thin aluminum inserts or foldable plastic bags and are used in a pressure-resistant outer container. When using these double-walled containers, the filling material is pressed out of the inner container by a gaseous propellant which is under increased pressure between the inner container and the outer container. This not only facilitates the metered delivery of the filling material, but also protects the filling material from undesired chemical reactions with the ambient air and leaves the exterior of the packaging unchanged in its form that is characteristic of sales.

Such double-walled packaging is well known and is characterized, for example, by a one-piece outer container which can be closed pressure-tight with a conventional valve. The deformable inner container is fastened in a groove of the outer container molded into the outer container and thus ensures maximum use of the available space.

Double-walled containers are also known in which the inner container consists of a foldable plastic bag. This plastic bag is glued directly to the valve housing and allows an ideal relationship to be established between the volume for the filling material and the intermediate volume for the pressure medium in a simple manner.

Unfortunately, this type of pressure vessel shows that the inner vessel empties in different ways, i.e. an undetermined residual volume of the contents remains in the inner container. This seems to occur in particular whenever the most easily deformable middle part of the inner container has collapsed when the filling material is emptied and thus leads to a local constriction of the inner container. This disadvantage is of particular importance in the case of industrial fluids, since predetermined amounts are often required when they are used.

It has therefore already been proposed to insert a riser pipe in the flexible inner container, which is provided with openings along its entire length in order to prevent such a local closure. However, such risers are in no way suitable for viscous or pasty contents, such as silicones or greases, since the pressure inside the pressure vessel is not sufficient to overcome the flow resistance of these technical fluids and to increase them due to the relatively long and thin riser press.
Another disadvantage is that, for procedural reasons, the inner bag does not have to be attached to the valve body itself, but to the riser pipe. This means that the inner bag comes to lie relatively deep and thus the space for the contents is undesirably limited.

The present invention seeks to remedy this and to provide means for making known double-walled containers also usable for dispensing technical fluids or other viscous products. In particular, the present Invention the remaining quantity of filling material remaining in the inner container can be kept as constant as possible in a reliable manner during all emptying.

According to the invention, this object is achieved with a squeeze-out grille which has the features of claim 1.

In its most general form, the squeeze grate according to the invention has a cup-shaped grille body provided with a plurality of openings, the openings of which are dimensioned in accordance with the flow behavior of the filling material. The mouthpiece of the cup-shaped lattice body has a collar part suitably shaped for attachment to the outer container. In the preferred embodiment, a fastening zone is provided between this collar part and the lattice body provided with the openings, which ensures proper fastening of the inner bag to the extrusion grid. The openings in the lattice body are designed as slots and the bottom part of the same is perforated and, in one embodiment, has two cross-shaped struts. In the preferred embodiment, the inner bag is welded to the fastening zone in order to be able to ensure a pressure-resistant connection between the inner bag and the press-out grille. In a further development of the embodiment according to the invention, the slots are asymmetrical, which on the one hand facilitates their production and on the other hand the flow behavior of the fluid can be influenced by these slots.

According to the invention, the advantages of such a squeeze grate lie in the controllable delivery of a predetermined quantity of filling material. The individual dimensioning of the lattice body and its openings allows the ejection pressure to be optimized depending on the volume ratio of the two-chamber container and the viscosity of the filling material.

It goes without saying that geometric modifications of the squeeze grate are within the range of the normal technical action of the person skilled in the art. In particular, the bottom part of the squeeze grate be completely open and dimensioned so that this part is first pressed together.

A lenticular cross-section of the lattice body and in particular the fastening zone also proves to be advantageous.

The invention is to be explained in more detail below with the aid of a special exemplary embodiment and with the aid of the figures.

Fig. 1:

eine schematische Längsschnitt-Darstellung durch einen konventionellen Zweikammerbehälter mit einem nur teilweise entleerten Innenbeutel;

Fig. 2:

eine schematische Längsschnitt-Darstellung durch einen konventionellen Zweikammerbehälter mit einem nur teilweise entleerten Innenbeutel und einem Steigrohr;

Fig. 3:

eine schematische Ansicht eines erfindungsgemässen Auspressgitters;

Fig. 4:

einen schematischen Querschnitt durch ein erfindungsgemässen Auspressgitter;

Fig. 5:

eine schematische Darstellung eines dosenförmigen Spenders mit einem erfindungsgemässen Innenbeutel;

Fig. 6:

eine schematische Darstellung eines flaschenförmigen Spenders mit einem erfindungsgemässen Innenbeutel.

Show it:

Fig. 1:

is a schematic longitudinal sectional view through a conventional two-chamber container with an only partially emptied inner bag;

Fig. 2:

is a schematic longitudinal sectional view through a conventional two-chamber container with an only partially emptied inner bag and a riser pipe;

Fig. 3:

a schematic view of a press-out grid according to the invention;

Fig. 4:

a schematic cross section through an inventive grating;

Fig. 5:

a schematic representation of a can-shaped dispenser with an inner bag according to the invention;

Fig. 6:

is a schematic representation of a bottle-shaped dispenser with an inner bag according to the invention.

Figure 1 shows a double-walled pressure vessel 1 with a dimensionally stable outer container 2 and a valve 3, which is attached to a valve plate 4. This valve plate 4 closes the outer container 2 pressure-tight. A crimp 5 provides this pressure-resistant connection between the valve plate 4 and Outer container 2 safely. The inner container shown in this figure consists of an aluminum bag 6 which is attached to the valve body with its upper end. Figure 1 shows the disadvantages of known two-chamber boxes. With these conventional containers, the inner container collapses in an irregular and uncontrollable manner. In particular, with this type of emptying, constrictions 7 form, which impede the emptying of the inner bag 6 in an undesirable manner and occur in a random manner.

No significant improvement is achieved with two-chamber boxes 2, in which the valve 3 is equipped on the inside with a riser pipe 8. Figure 2 shows such a two-chamber box, which in turn is closed with a valve plate 4 pressure-tight. The clinched valve 3 has a riser pipe 8, which in one development is provided with perforations over its entire length. It has been shown that the residual filling quantity of the filling material is also not constant in this embodiment. In particular, this embodiment is not suitable for dispensing pasty or gel-like contents, such as silicone or technical fats.

FIG. 3 shows a preferred embodiment of a press-out grille 9 according to the invention, with a cup-shaped grille body 11 and a mouthpiece 12, which essentially comprises a fastening zone 13 for the inner bag 6 and a collar part 14. In this embodiment, the lattice body has slots 15 which are dimensioned accordingly to the filling material. It goes without saying that these slots 15 can also run in the horizontal direction or are distributed over the lattice body in such a way that it collapses in a predeterminable manner. In particular, these slots 15 can be made in the lattice body 11 in any shape and distribution. Likewise, the fastening zone 13 can be designed in such a way that a pressure-resistant connection between the squeeze grid 9 and the inner bag 6 can be ensured. In particular, the materials can be selected so that they can be glued, pressed or welded in a simple manner. In a preferred embodiment the squeeze grid is made of plastic and is welded with a coated plastic bag. The fastening zone (13) preferably has a lenticular cross section, the plane of symmetry of which is aligned with the weld seam of the flat plastic bag. The collar part 14 serves to fasten the press-out grid and is dimensioned accordingly. In a preferred embodiment, the collar part 14 has a bulge which is curved outwards in order to allow sufficient space for the expansion of the valve plate side wall when the valve plate is attached to the outer container 2 with the clinching. In particular, the collar part 14, instead of between the outer container 2 and valve plate 4, respectively. Container closure 19, be attached directly to the valve plate 4 or outer container 2, which individual parts can be glued, pressed, welded or formed in one piece, depending on the material.

FIG. 4 shows a cross section through a lattice body 11 according to the invention and makes the non-radially symmetrical arrangement of the slot-shaped openings 15 clear. These facilitate the inflow of the filling material in an excellent direction, while the flow resistance for the filling material is substantially increased in a direction perpendicular to this direction. This is particularly useful when the inner container is not designed to be axially symmetrical but as a flat bag, and therefore the filling material should preferably flow in a predetermined direction. It goes without saying that the squeeze grid 9 and inner bag 6 are aligned accordingly in these cases. For this purpose, the excellent flow direction of the slots (15) and the plane of symmetry of the lenticular fastening zone (13) are parallel to one another. In the embodiment shown, the base part has two cross struts 16 arranged in a cross shape. It goes without saying, however, that only one such cross strut 16 can be provided or that such a strut can be dispensed with entirely. It is again in the area of ordinary professional action to arrange such cross struts 16 somewhere in the lattice body 11, in particular also around to influence the collapse behavior of the lattice body 11 in the desired manner.

FIG. 5 shows the use of the press-out grille 9 according to the invention in a standardized pressure container 2. The collar part 14 fits snugly on the rolled edge 5 of the outer container 2. The valve plate 4 is clinched in a tried and tested manner with the rolled edge 5 of the outer container 2 in a pressure-tight manner. The filling material can be placed in the open container 1 before the valve plate is placed on it, or can be pressed through the valve 3 into the inner bag 6 after the valve plate 4 has been fastened. The propellant is introduced in a known manner through a bottom hole 17 which can be closed with a stopper. The inner bag 6 fastened to the fastening zone 13 of the squeeze grid 9 is dimensioned in accordance with the desired volume ratios. It is important to ensure that the volume of the intermediate chamber 18 receiving the propellant and the pressure generated by the propellant introduced are sufficient to squeeze the filling material up to a predetermined residual amount. This dimensioning essentially results from Boyle-Mariotte's law.

FIG. 6 shows the use of the extrusion grid 9 according to the invention in a plastic bottle which can be closed with a pressure-tight closure 19. This can either be filled directly in the open state and provided with a propellant in a known manner or filled in via the valve in the closed state. The advantages of this use are obvious and are not only to be seen in the determinable amount of emptying, but in particular in the simple disassembly, reusability and disposability.

Claims (10)

Squeeze grate (9) for an inner bag (6) of a double-walled container (1), preferably a pressure vessel with a valve (3), as is used for dispensing flowable products, in particular cosmetic and technical fluids, which squeeze grid (9) consists of a cup-shaped lattice body (11) with a plurality of openings (15) and a mouthpiece (12), which comprises a fastening zone (13) for fastening the inner bag (6) to the extrusion grid (9), and a collar part (14) for fastening of the squeeze grid (9) on the container (1). Squeeze-out grate according to claim 1, characterized in that the volume enclosed by it in the emptied state is dimensioned correspondingly to the container (1) in such a way that this volume corresponds to the volume of the intermediate chamber (18) filled with a propellant when the inner bag (6) is filled, is in the same ratio as the pressure of the propellant when the inner bag (6) is full to the pressure required to squeeze the contents out of the container (1) up to a predetermined residual amount. Squeeze grate according to claim 2, characterized in that the openings (15) are designed as slots. Squeeze grate according to claim 3, characterized in that the openings (15) define a preferred direction of passage. Squeeze-out grate according to one of claims 1 to 4, characterized in that the collar part (14) is molded directly onto the valve (3) or the valve plate (4). Squeeze-out grate according to one of claims 1 to 4, characterized in that the collar part (14) is attached to the valve (3) or valve plate (4). Squeeze grate according to one of claims 1 to 4, characterized in that the fastening zone (13) has a lenticular cross section. Inner bag with an extrusion grid according to one of claims 1 to 7 for a double-walled container. Double-walled container with an extrusion grid according to one of claims 1 to 7. Double-walled container according to claim 9, characterized in that the outer container is a plastic bottle.

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