NL1034974C2 - Method and device for dispensing a product from a container as a mist or foam. - Google Patents

Description

METHOD AND DEVICE FOR DISPOSING A PRODUCT FROM A HOLDER AS A SPRAY OR FOAM

The invention relates to a method for dispensing a product from a container as a spray or foam, by introducing a gaseous displacement medium into the container under pressure and mixing at least a part of the displacement medium during the product to be dispensed . Such a method is generally known.

In the known method, the product is atomized or foamed by a propellant gas, which is included in the container together with the product. A part of this propellant gas dissolves in the product, and when the product is released it goes out of solution, as a result of which the product is sprayed or foamed. This known method of spraying or foaming has a number of disadvantages.

Thus, the propellant gas must initially be received under a relatively high pressure in the container, in order to ensure that there will be sufficient pressure to also be able to spray or foam the last residues. This places high demands on the material and construction of the container. In general, the container is made of metal, and is constructed to be relatively heavy. Due to the high pressure, the container may only have a small volume in order to limit the risks in the event of an explosion. Therefore, relatively much packaging material is required per unit of product, and the costs are high. In addition, relatively strict requirements apply for the transport and storage of containers under pressure, which further increases costs. Finally, due to the direct contact between the propellant gas and the product to be dispensed, the known method is not suitable for every product, inter alia because the shelf life of the product can be influenced by the propellant gas.

The invention now has for its object to provide an improved method of spraying or foaming, wherein the aforementioned disadvantages do not occur, or at least to a lesser extent. According to a first aspect of the invention, this is achieved in a method as described above in that ambient air is used as the displacement medium by a pump pressurized.

By using ambient air as the displacement medium, the necessary pressure for atomizing or foaming the product can be easily generated when the product has to be delivered. As a result, it is not necessary to always keep the container under pressure, so that no special requirements apply to storage and transport, as a result of which the logistics are considerably simplified. Moreover, in this way, exactly the right pressure can always be used for each product. In particular, the initial pressure now need not be higher than is necessary for spraying or foaming, so that the container can be constructed in a simpler and lighter manner, for instance of plastic. Due to the lower occurring pressures, the container can also have a larger volume.

According to a second aspect, the invention provides a method as described above, wherein the displacement medium in the container is kept separate from the product by a membrane and is only mixed with the product when it is dispensed. In this way, direct contact between the product and the displacement medium is prevented until the moment that the product is dispensed, so that the product cannot be influenced by the displacement medium.

3

Preferred variants of the method according to the invention are described in the subclaims 3 and 4.

The invention also relates to a device for dispensing a product as a spray or foam, comprising: - a container for the product with at least one dispensing opening, which container is adapted to receive a gaseous displacement medium under pressure, and - means for mixing at least a part of the displacement medium with the product 10 to be dispensed. Such a device is generally known in the form of a spray can.

The known device has the disadvantages discussed above in the context of the method.

The invention has for its object to further develop a device of the above-mentioned type such that the disadvantages discussed do not occur, or at least to a lesser extent. According to a first aspect of the invention this can be achieved with such a device through at least one supply opening through which displacement medium can be introduced into the container. Thus, as displacing medium, ambient air can be used, which is pressurized by an external pump and then pressed into the container through the supply opening.

According to a second aspect, the invention provides a device of the type described above, wherein the container has a membrane for separating the displacement medium and the product, and the mixing means are arranged in the vicinity of the dispensing opening. This makes it possible to avoid direct contact between the product and the displacement medium until the product is dispensed from the container.

4

The membrane is preferably formed by a flexible inner container accommodated in the container and connecting to the dispensing opening, in which the product or the displacement medium is accommodated. A holder with such an inner holder can be manufactured simply and at low costs. Examples of such containers are described in applicant's non-prepublished Dutch patent applications 1033582, 1034419 and 1034895.

In a preferred embodiment of the device according to the invention, the mixing means are adapted to separately deliver a small amount of displacement medium after and / or before the product is dispensed as mist or foam. In this way the dispensing opening is, as it were, "blown through" before and after use, thereby preventing product 15 from being left behind. Such residual product could dry out, thereby affecting the operation of the device, or even spoil it, if the product to be dispensed is a food product.

This "blowing through" can be achieved in a constructively simple manner if the mixing means comprise a mixing chamber arranged between the dispensing opening and the container and closable by a movable valve, the valve being movable between a first, fully closed end position, an intermediate position, in which it is only opened for the displacement medium, and a second, fully opened end position. When moving between the end positions at the beginning and the end of the delivery of the product, the valve then each time reaches the intermediate position into which only displacement medium can pass.

In order to prevent unintended escape of product from the holder, the device is preferably provided with means for biasing the valve to the first, closed end position. In a constructionally simple embodiment of the device, these biasing means comprise at least one spring integrally formed with the holder and engaging the valve.

In another preferred embodiment of the device 5, the mixing means are adapted to mix the displacement medium in a fixed ratio with the product to be dispensed.

This ensures optimum spraying or foaming under all circumstances. This can be achieved in a constructively simple manner when the mixing chamber 10 has feed openings for the product and the displacement medium, and the mixing ratio is determined by the ratio between the flow surfaces of the respective feed openings. The design of the mixing chamber can then be easily optimized for spraying or foaming the product to be dispensed.

The invention is now elucidated on the basis of an example, wherein reference is made to the accompanying drawing, in which:

FIG. 1 is a longitudinal section through a device 20 according to the invention,

FIG. 2 is a detailed view on an enlarged scale according to the arrow II in FIG. 1, in which the device is shown in the closed rest position,

FIG. 3 is a view similar to FIG. 2 of the device during "blowing through" at the start of a dispensing cycle, and

FIG. 4 is a view corresponding with FIGS. 2 and 3 of the device during dispensing of the product.

A device 1 for dispensing a product P as a spray or foam comprises a holder 2 for the product P, which is provided with a dispensing opening 3 (fig. 1). The holder 2 is adapted to receive a gaseous displacement medium D under pressure. For this purpose, a closable supply opening 9 is formed in a bottom 8 of the holder 2, through which the displacement medium D can be introduced into the holder 2. The container 2 can be made by injection molding, followed by blow molding, from a plastic such as, for example, polyethylene terephthalate (PET). The device 1 also comprises means 4 with which a part of the displacement medium D can be mixed with the product P to be dispensed. These mixing means 4 are arranged in the vicinity of the discharge opening 3.

The container 2 has a membrane 5 for separating the displacement medium D and the product P, which membrane 5 is here formed by a flexible inner container. This inner container 5, just like the container 2 itself, can be manufactured by an injection molding process, followed by blow molding. Polypropylene (PP) is suitable as material for the inner container 5, for example. The product P is included in this inner container 5, which is accommodated in the container 2 and which connects to the dispensing opening 3. The displacement medium D can then be pressed into the space 13 between the inner container 5 and the wall of the container 2. However, the reverse situation is also conceivable: the displacement medium D can be pressed into the inner container 5, while the product P can then be accommodated in the remaining space 13 within the container 2.

An immersion tube 6 is arranged in the inner container 5, extending from a neck 7 of the container 2 to near the bottom 8. Through this immersion tube 6 the product P to be dispensed is fed from the inner container 5 to the mixing means 4. In addition, this immersion tube 6 serves to prevent the inner container 5 from being compressed when it is emptied, as a result of which possibly parts of the product P to be dispensed would be "cut off" from the dispensing opening 3, and thus in the container 2. stay behind.

7

The mixing means 4 here comprise a mixing chamber 10, which is arranged between the dispensing opening 3 and the interior of the container 2. The mixing chamber 10 has a first supply opening 11 which is connected via a first conduit 12 to the space 13 left free by the inner container 5, and a second supply opening 14 which is connected via a second conduit 15 partially inserted into the mixing chamber 10 to the interior of the inner container 5. The supply openings 11, 14 can be closed or released by a movable valve 16.

This valve 16 is slidably arranged around the end of the second conduit 15 and can be moved between a first end position in which the two supply openings 11, 14 are closed (Fig. 2) and a second end position, in which the two supply openings 11, 14 are in be connected to the mixing chamber 10 (Fig. 4). Between these two end positions, the valve 16 can assume a position in which the first supply opening 11 is released while the second supply opening 14 remains closed (Fig. 3). In this intermediate position the displacement medium D can flow into the mixing chamber 10 and subsequently flow away around the projecting part of the second conduit 15 to a dispensing conduit 17 which opens into the dispensing opening 3.

The valve 16 is biased to its first, closed end position by biasing means 18. In the example shown, these biasing means 18 comprise a bending spring 19, which is formed integrally with the holder 2. The valve 16 can be moved to its second end position by pressing down an operating button 20, which is slidably received in a cap 21 disposed around the neck 7 of the holder 2. With this operating button 20 a wedge-shaped, on the bending spring 19 engaging element 22 which, with increasing depression of the button 20, moves the 8 spring 19 further and further away from the second line 15. As a result of the decrease in the spring pressure, the valve 16 is then pushed off the second line under the influence of the pressure in the inner container 5. When the control button 20 is released, the bending spring 19 returns to its starting position, whereby the valve 16 is moved again to the first, closed end position and the control button 20 is pushed up to its rest position.

When the valve 16 is in the second, fully opened, end position, the ratio between the flow surfaces of the first and second supply openings 11, 14 determines the ratio in which the displacement medium D is mixed with the product P to be dispensed. This is due to the fact that the pressure in the inner container 5 is equal to the pressure in the space 13 around the inner container 5. Apart from small pressure losses as a result of the design of the first and second conduits 12, 15, the pressure is thus including the product P and the displacement medium D flowing into the mixing chamber 10 equally. In any case, the pressure ratio is constant, because any pressure losses are determined by the construction of the device. This means that the mixing ratio is also constant.

The operation of the dispensing device 1 is therefore as follows. First, displacement medium D, which is for example pressurized by a pump, is introduced into the space 13 between the inner container 5 and the wall of the container 2 via the supply opening 9. As a result, the product P in the inner container 5 is also pressurized. The operating button 20 is then depressed, as a result of which the wedge-shaped engagement element 22 starts to bend the spring 19 away.

As a result, the valve 16 begins to move from its first, closed end position toward its second, open end position.

9

When the valve 16 reaches its intermediate position, the first supply opening 11 is released, so that the displacement medium D flows into the mixing chamber 10 and flows from there along the projecting part of the second line 15 to the dispensing line 17 and the dispensing opening 3. As a result, the dispensing line 17 is "blown clean".

When the valve 16 subsequently reaches its second, open end position, the product P also flows into the mixing chamber 10 via the second supply opening 14, where it is mixed with the displacement medium D which is still flowing in. This is the first and only time that the displacement medium D comes into contact with the product P. Subsequently, the mixture of product P and displacement medium D flows through the dispensing line 17 to the dispensing opening 3, where it emerges as a mist or a foam.

When the operating button 20 is subsequently released, the spring 19 pushes up the wedge-shaped engagement element 22 and the valve 16 to its first, closed end position.

Thereby, the valve 16 again passes its intermediate position, in which the second supply opening 14 is already closed, while the first supply opening 11 still remains free. In that position, therefore, only displacement medium D is released again, as a result of which the dispensing line 17 is again blown clean, before the valve 16 completely terminates the delivery of product P and displacement medium D.

The invention thus makes it possible to dispense a product in the form of a mist or foam, without thereby making use of a propellant gas enclosed in a container. A relatively lightly constructed container can thus suffice, which moreover can have a relatively large volume. Moreover, the invention makes it possible to spray or foam a product without having to be in contact with a gas-forming medium for a long time. Thus influencing the product by the gas-forming medium is largely prevented.

Although the invention has been discussed above with reference to an example, it will be clear that it is not limited thereto. For example, the inner holder 5 could not only be attached to the holder 2 at the neck 7, but also at the bottom 8, as described in the aforementioned Dutch patent application 1034419. In that case, it could be dispensed with the use of the immersion tube 6, because the inner holder 5 would then be kept open by the additional attachment. Also, the inner holder 5 could be attached to the circumferential wall of the holder at some places by welding or an adhesive connection, as described in the aforementioned Dutch patent application 1034895. Even the inner holder 5 could be manufactured integrally with the holder 2, as described. in the aforementioned Dutch patent application 1033582, so that it would be over its entire circumference with the wall of the holder 2. In that case, the first conduit 12 should extend over substantially the entire height of the container 2 to the space between the bottom of the inner container 5 and the bottom 8 of the container 2.

Furthermore, the mixing means 4 can be designed differently than shown and described here, while the shape and construction of the biasing means 18 can also be varied in many ways. And instead of a vertically movable operating button 20 on the top side of the cap 21, it could also be arranged at the front and be horizontally movable.

The scope of the invention is therefore solely determined by the following claims.

1034974

Claims (13)

Method for dispensing a product from a container as a spray or foam, by introducing a gaseous displacement medium under pressure into the container and mixing at least a part of the displacement medium with the product to be dispensed, characterized in which is used as a displacement medium by pressurized ambient air. 2. Method as claimed in claim 1 or the preamble thereof, characterized in that the displacement medium in the container of the product is kept separate by a membrane and is only mixed with the product when it is dispensed. 3. Method as claimed in claim 1 or 2, characterized in that after and / or before the product is dispensed as mist or foam, a small amount of displacement medium is released separately. Method according to one of the preceding claims, characterized in that the displacement medium is mixed with the product to be dispensed in a fixed ratio. Device for dispensing a product as spray or foam, comprising: - a holder for the product with at least one dispensing opening, which holder is adapted to receive a gaseous displacement medium under pressure, and 25. means for dispensing with it product to be dispensed mixing at least a part of the displacement medium, characterized by at least one supply opening through which displacement medium can be introduced into the container. 6. Device as claimed in claim 5 or the preamble thereof, characterized in that the holder has a membrane for separating the displacement medium and the product, 1034974 and the mixing means are arranged in the vicinity of the dispensing opening. 7. Device as claimed in claim 6, characterized in that the membrane is formed by a flexible inner container received in the container, connecting to the dispensing opening, in which the product or the displacement medium is accommodated. 8. Device as claimed in any of the claims 5 to 7, characterized in that the mixing means are adapted to separately deliver a small amount of displacement medium after and / or for dispensing the product as mist or foam. 9. Device as claimed in claim 8, characterized in that the mixing means comprise a mixing chamber arranged between the dispensing opening and the container and closable by a movable valve, wherein the valve is movable between a first, fully closed end position, an intermediate position, wherein it is only opened for the displacement medium, and a second, fully open end position. 10. Device as claimed in claim 9, characterized by means for biasing the valve to the first, closed end position. Device as claimed in claim 10, characterized in that the biasing means comprise at least one spring integrally formed with the holder and engaging the valve. Device according to any of claims 5 to 11, characterized in that the mixing means are adapted to mix the displacement medium in a fixed ratio with the product to be dispensed. Device as claimed in claims 9 and 12, characterized in that the mixing chamber has feed openings for the product 30 and the displacement medium, and the mixing ratio is determined by the ratio between the flow surfaces of the respective feed openings. 1034974