WO2013053561A1

WO2013053561A1 - Nozzle assembly

Info

Publication number: WO2013053561A1
Application number: PCT/EP2012/067837
Authority: WO
Inventors: Carlo di FOGGIA
Original assignee: Unilever N.V.; Unilever Plc; Hindustan Unilever Limited
Priority date: 2011-10-10
Filing date: 2012-09-12
Publication date: 2013-04-18

Abstract

The present invention relates to a nozzle assembly (1) comprising a valved foam-forming assembly (2), provided with a cover part (8), the inner space (10) of which is adapted to receive the valved foaming assembly, such that the outlet port (7) of the foam-forming assembly and the outer opening (12) of the cover part are located in one plane. According to another aspect, the invention also provides a closable nozzle system comprising a nozzle assembly according to the invention and a cap (19). The invention also relates to a method for the leak and spill-safe closing of a container equipped with a valved foaming nozzle assembly.

Description

NOZZLE ASSEMBLY

FIELD OF THE INVENTION The present invention relates to a nozzle assembly. In

particular, the invention relates to a nozzle assembly that can dispense a gas/liquid mixture in the form of a foam and be sealed in a spill-proof way. The invention also relates to a method for the leak-proof and spill-proof closing of a

container equipped with a valved foaming nozzle assembly.

BACKGROUND TO THE INVENTION

Containers adapted for dispensing a liquid such as a cleaning liquid, in the form of a spray or a foam are generally known in the art. If for instance a surface is to be treated with a liquid composition, dispensing the liquid as a spray or foam may be desirable to obtain a good surface coverage. This particularly applies to the dispensing of liquids intended for hard surface cleaning.

Dispensing a liquid as a spray or a foam, generally requires intimate interdispersion of the liquid and a gas, typically air. A well-known means to accomplish this is a nozzle

comprising a liquid inlet port, an air inlet port, and an outlet passage for the mixture. Typically, the liquid and the gas are forced to flow through the nozzle by increasing their pressure with respect to the outside of the nozzle.

Dispensability in the form of either a spray or a foam

generally depends on the properties of the liquid in

combination with properties of the nozzle. Compared to sprays, foams may be preferred if the liquid to be dispensed is a cleaning liquid that is e.g. sticky for improved surface contact time.

A simple foam or spray dispensing container typically operates by increasing the inside pressure on both liquid and air by squeezing the container. Upon releasing the container, air may flow back in via the nozzle. However, one or more separate air inlet ports may enable air to flow back into the container more efficiently, thereby for example reducing the time between repeated squeezes, or reducing the risk of clogging the nozzle. Typically, such air inlet ports are valved to ensure

unidirectional flow. For instance, US 4,093,124 discloses an atomiser comprising non-return valves, constituted e.g. by a resilient washer.

Alternatively, US 5,037,006 and EP 2094394B1 disclose a squeeze bottle foam dispenser and a foam-forming assembly,

respectively, both of which comprise valved inlet and outlet ports . Typically, the air inlet ports are located away from the foam outlet, as can be seen in EP 2094394B1. This placement of the inlet ports constitutes a problem, however. Especially if a the container is intended for use with cleaning liquids - which may be aggressive or corrosive - the container should be closable such that the contents cannot be spilled during storage or upon reopening. This generally requires a closing member such as a cap and moreover, one or more leak proof seals between the closing member and the container comprising the nozzle. An additional problem, in view of consumer safety, is possible fluid communication between dead space inside the cap and the interior of the container. Such communication might lead to the accumulation of liquid in the dead space, which may lead to dangerous spilling or splashing upon reopening by the consumer. This is particularly undesirable in case of a container

intended for corrosive liquids such as bleach.

This problem might be solved by separately closing each outlet and inlet port by individual closing members, but this is complex, susceptible to defects or to accidental omission, and hence this is less safe in the hands of an average consumer. Alternatively, a cap having an inner structure of pins and or ridges adapted to form a large number of individual seals for the individual orifices would require complicated manufacture, and would be fault-prone, especially during extended use, since wear of a single seal may already lead to the above undesirable situation . Therefore, it is an object of the present invention to provide a nozzle assembly that can be sealed in a leak-proof and/or spill proof way. In is a particular object of the invention to provide such a nozzle assembly that is capable of dispensing a foam.

It is a general object of the present invention to provide a nozzle assembly that overcomes one or more of the problems observed in the prior art as described above. It is a further object of the present invention to provide a nozzle assembly adapted to be closable by a single closing element such as a cap.

It is another object of the present invention to provide a nozzle assembly fit for leak proof closing such that only a low number of sealing contacts is required between a closing member and any inlets or outlets in the nozzle assembly adapted to be in fluid communication with the interior of the container. Subsequently, it is an object of the invention to provide leak proof and spill proof systems including a nozzle assembly and cap a preferably also a container.

Furthermore it is an object to provide a method for the leak- proof and spill-proof closing of a container comprising a nozzle, preferably fit for dispensing a foam. We have found that one or more of these objects can be achieved by the nozzle assembly of the present invention. This invention relates to a nozzle assembly comprising a valved foam-forming assembly, provided with a cover part, the inner space of which is adapted to receive the valved foaming assembly, such that the outlet port of the foam-forming assembly and the outer opening of the cover part are located in one plane. The nozzle assembly can thus be closed leak-proof and spill-proof with a closing member of relative straightforward construction. Thus, the nozzle assembly is particularly useful for

application in combination with containers for storage and dispersion of liquid compositions, especially liquid cleaning compositions . DEFINITION OF THE INVENTION

Accordingly, in a first aspect the invention provides a nozzle assembly (1) comprising

a valved foam-forming assembly (2), comprising

· one or more outer air inlet ports (3) ,

• one or more inner air inlet ports (4),

• one or more inner fluid inlet ports (5) , and • a dispensing passage (6) comprising an outlet port (7) ,

• wherein the outlet port (7) is located away from the outer air inlet ports (3) , as defined herein;

a cover part (8) comprising

• an inner opening (9)

• an inner space (10) and

• a cover passage (11) comprising an outer cover opening ( 12 ) ,

characterised in that

the inner space (10) of the cover part (8) is adapted to receive the valved foaming assembly (2), whereby upon receiving

• the dispensing passage (6) is substantially

concentric with the cover passage (11),

• the outlet port (7) and the outer cover opening (12) are located in one plane,

• the inner cross-sectional area (A) of the outer cover opening (12) is larger than the area (B) enclosed by the outer edge (13) of the outlet port (7),

• such that the area (C) of the outer cover opening

(12) outside outlet port (7) is in communication with the one or more outer inlet ports (3) . According to a second aspect of the invention, there is provided a closable nozzle system (18) comprising

a nozzle assembly (1) according to the invention, and a cap (19) ;

whereby the nozzle assembly (1) is adapted to receive the cap (19), and the cap (19) comprises a planar region (20) adapted to form a seal with the wall of the cover passage (11) upon placement of the cap (19) on the nozzle assembly (1) . In a third aspect the invention provides a container system for the dispensing of foam, comprising a closable foaming nozzle system (18) according to the invention, and a container (23) comprising at least one opening (24);

whereby the opening (24) is adapted to receive the inner opening (9) of the cover part (8) equipped with the valved foam-forming assembly (2), such that the inner space of the container (23) is in communication with the one or more inner air inlet ports (4), and the one or more inner fluid inlet ports (5) of the foam-forming assembly (2) .

In a fourth aspect the invention provides a method for the leak-proof closing of a container equipped with a valved foam- forming nozzle assembly and optionally for the dispensing of a foamable liquid composition comprising the steps:

a. providing a container system according to the invention; b. filling the container (23) with the foamable liquid

composition;

c. connecting the cover part (8) equipped with the valved foam-forming assembly (2) to opening (24);

d. closing the outer cover opening (12) by applying the cap (19) ;

e. optionally opening the outer cover opening (12) by

removing the cap (19);

f. after opening the outer cover opening (12), optionally increasing the pressure inside the container (23) thereby dispensing at least part of the foamable liquid composition from the container (23) via the nozzle assembly (1); and

g. optionally repeating steps (d) and (e) and/or (f) . A fifth aspect of the invention is use of a cover (8) to provide a leak-proof closable container system comprising a nozzle assembly (2) according to the invention.

BRIEF DESCRIPTION OF FIGURES

Figure 1 provides a schematic side-view cross-section of a non- limiting example of a nozzle assembly according to the present invention.

Figure 2 provides a top-view projection of the cover part of Fig. 1.

Figure 3 provides a top-view projection of the nozzle assembly of Fig. 1.

Figure 4 provides a side-view projection of a closable foaming nozzle assembly system, comprising a foam-forming assembly, a cover part and a cap.

Figure 5 provides a cross-section through the plane indicated by the line V-V in Fig. 4.

Figure 6 provides a detail of an alternative cap design in a magnified view corresponding to region VI in Fig. 5.

Figure 7 provides a detail of an alternative cap design in a magnified view corresponding to region VI in Fig. 5.

Figure 8 provides a schematic side-view cross-section of a non- limiting example of a container system according to the present invention, comprising a closable foaming nozzle system and a container .

Figure 9 provides a detail of the nozzle system of Fig. 8, in a magnified view corresponding to region IX in Fig. 8. DETAILED DESCRIPTION OF THE INVENTION

For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean

"including" but not necessarily "consisting of" or "composed of". Thus, the term "comprising" is meant not to be limiting to any subsequently stated elements but rather to optionally also encompass non-specified elements of major or minor functional importance. In other words, the listed steps or options need not be exhaustive. Whenever the words "including" or "having" are used, these terms are meant to be equivalent to

"comprising" as defined above. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se.

Except in the examples, or where otherwise explicitly

indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about". Unless specified otherwise, numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated .

In the context of this description two directions are

essentially parallel when the acute angle between the

directions is smaller than 10 degrees, preferably smaller than 5 degrees, more preferably smaller than 2 degrees. In the context of this description, two directions are essentially perpendicular when the acute angle between the directions is larger than 80 degrees, preferably larger than 85 degrees, more preferably larger than 88 degrees. The angle between two planes is considered to be the angle between their normal directions. The angle between a line and a plane is considered to be 90 degrees minus the angle between the direction of the line and the direction normal to the plane.

Nozzle assembly

The nozzle assembly 1 of the first aspect of the invention comprises a valved foam-forming assembly 2 and a cover part 8 as its main elements as can be seen in Fig. 1.

The functioning of the nozzle assembly is best described when it is attached to a container 23. Thus, ports, openings

orifices etc. of the foam-forming assembly and the cover parts are termed "inner" and "outer" in correspondence to whether they are primarily communicating with the inside of the

container 23 or with its surroundings, respectively. Such a container typically contains a liquid and a gas phase.

Foam-forming assembly

The valved foam forming assembly 2 comprises one or more outer air inlet ports 3, one or more inner air inlet ports 4, one or more inner fluid inlet ports 5, and a dispensing passage 6 comprising an outlet port 7.

The foam-forming assembly 2 is valved. This means that it comprises elements capable of restricting the direction of fluid or gas flow through inlet or outlet ports or passages of the assembly. This may for instance be effected by one or more valve members, such as ball check valves, swing check valves, or resilient members such as diaphragm check valves, or

membranes. Preferably, the one or more valve members are arranged such that at least the direction of flow through the one or more outer air inlet ports 3 is restricted to the inward direction. For generality, the valve members are not shown in Figures 1 and 4. Figure 8 provides an example of a nozzle assembly according to the present invention in which the valve members 27 are shown. An example of a valved foam-forming assembly comprising a valve membrane may be found in the patent document EP 2 094 394 Bl, which is hereby incorporated by reference. Thus, in a typical foam-forming assembly suitable for use in the present invention, the one or more inner air inlet ports 4, and one or more inner fluid inlet ports 5 serve to allow both a gas (air) and a liquid to enter the assembly from a container which may be connected to the assembly. For instance, exerting a pressure on the liquid and gas may drive them through the respective inlet ports.

A dip tube 25 may for example be connected to either the inner air inlet ports 4 or the inner fluid inlet ports 5, depending on whether the container system is intended for up-right or upside-down use. Upon the exertion of the aforementioned pressure, the fluid and air may intimately mix inside the foam- forming assembly and subsequently emanate from the outlet port 7, preferably in the form of a foam. The outer air inlet ports 3 serve to allow air to flow in after dispensing an amount of foam. Generally, such ports may be valved such that only an inward flow of air is allowed. The present invention involves foam-forming assemblies in which the outlet port 7 is located away from the outer air inlet ports 3. This may be required by design considerations relating to optimising the foam dispensing, but constitutes a problem in the context of leak-proof and spill-proof closing of the assembly. In this context, "located away" means that the air inlet ports 3 are so far removed from the outlet port 7 that they cannot be simultaneously covered by the same smoothly curved or preferably planar area of a closing member. Thus, "located away" preferably refers to a state wherein the outlet port 7 is located at a shortest distance along the outer surface of the foaming nozzle assembly 2 of at least 2 times, more preferably 2 to 10 times, or even more preferably 3 to 5 times the diameter of the outlet port 7. Thus, the air inlet ports 3 are preferably not located in a plane that runs through the centre of the outlet port 7, and is essentially

perpendicular, more preferably perpendicular to the principal direction Z of the dispensing passage 6.

In a preferred foam-forming assembly, the outer air inlet ports 3 are located in the base plane 15 which the dispensing passage 6 protrudes from. Alternatively, the outer air inlet ports 3 may be located in the side wall of dispensing passage 6.

A foam-forming assembly as disclosed in EP 2 094 394 is

particularly suitable for incorporation in the present

invention. The assembly comprises one or more air inlets 3 located in the base plane 15 and in addition to that may comprise further air inlets that enable the valving movement of the membrane that acts as a valve member. Thus it establishes a particular need to provide a leak-proof and spill-proof closure means .

The foam-forming assembly used in the present invention may be a foam-forming assembly known in the art, but it may also be an adapted foam-forming assembly. For instance, the placement and dimensions of the air inlets and the dispensing passage may be adapted . The foam-forming assembly 2 preferably comprises 1 to 10, more preferably 2 to 8, and even more preferably 3 to 6 outer air inlet ports 3. Similarly, the foam forming assembly 2

preferably comprises 1 to 10, more preferably 2 to 8, and even more preferably 3 to 6 inner air inlet ports 4 and also

preferably comprises 1 to 10, more preferably 2 to 8, and even more preferably 3 to 6 inner fluid inlet ports 5.

The foam-forming assembly 2 may be manufactured from one or more parts. For instance, the dispensing passage 6 and the base comprising the one or more inner fluid inlet ports 4 may be prepared as separate parts that are subsequently joined to constitute the foam-forming assembly 2, as is the case for instance for the foam-forming assembly according to

EP 2 094 394.

Cover part

The nozzle assembly of the present invention also involves a cover part 8, comprising an inner opening 9, an inner space 10, and a cover passage 11, comprising an outer cover opening 12.

Preferably, the inner opening 9 has a configuration, such that it can communicate with the inside of a container 23. The inner space 10 of the cover part 8 is adapted to receive the valved foam-forming assembly 2, whereby upon receiving the dispensing passage 6 is substantially concentric with the cover passage 11. That is, the dispensing passage 6 of the assembly 2 fits inside the cover passage 11, such that the principal axis Z of the dispensing passage 6 and the analogous principal axis of the cover passage 11 are essentially parallel, more

preferably parallel. Preferably, the closest separation of these principal axes is less than 0.5, more preferably less than 0.2, even more preferably less than 0.1 times the diameter of the outlet port 7. Still more preferably, these principal axes coincide. Moreover, the dimensions of dispensing passage 6 and cover passage 11 are such that upon placement of the assembly 2 in the inner space 10, the outlet port 7 and the outer cover opening 12 are located in one plane. Preferably, this plane is a plane Y that runs through the centre of the outlet port 7, and is substantially perpendicular - or, more preferably, perpendicular - to the principal direction Z of the dispensing passage 6. In the context of the present invention, outlet port 7 and outer cover opening 12 are considered to be located in one plane if their separation along the principal direction Z of the dispensing passage 6 is less than 0.2 times, more preferably less than 0.1 times, even more preferably less than 0.05 times the diameter of the outlet port 7.

Upon placement of the 2 in the inner space 10, air should still be able to flow into the one or more outer air inlets 3.

Therefore, the inner cross-sectional area A of the outer cover opening 12 is larger than the area B enclosed by the outer edge 13 of the outlet port 7, such that the area C of the outer cover opening 12 outside outlet port 7 is in communication with the one or more outer inlet ports 3. The areas A, B, and C are therefore related such that C = A - B, as appreciated from Fig. 2 and Fig. 3.

Subject to the above condition, both the dispensing passage 6 and the cover passage 11 may be independently shaped. Thus they may for instance be square, elliptical or circular in cross section. Hence, either passage may independently be for

instance a (rectangular) cuboid, a trapezoid, a truncated elliptic cone, a frustocone or a cylinder. The passages may also comprise segments of different such shapes. It is preferred that the passages 6 and 11 essentially consist of cylindrical and frustoconical segments. It is particularly preferred that the outer cover opening 12 is essentially circular. It is similarly preferred that the outlet port 7 is essentially circular. The dispensing passage 6 and the cover passage 11 are preferably adapted such that the area C in the outer cover opening 12 outside outlet port 7 forms an annular opening 14, as shown by the example of Fig. 1 and fig 3. The opening 14 is preferably narrow compared to 7, in order to minimise the probability of foam entering into or blocking the one or more outer air inlets 3. Therefore, the distance between the outer rim 13 of dispensing passage 6 and the confronting inner wall of cover passage 6 is preferably less than 0.5 times, more preferably less than 0.4 times, even more

preferably less than 0.3 times, still more preferably less than 0.2 times and yet more preferably less than 0.1 times the diameter of outlet port 7.

It is preferred that the cover part 8 is adapted to receive the foam-forming assembly 2 such that the dispensing passage 6 is centred in the cover passage 11.

To facilitate such centring, one or more centring supports 16 may preferably be provided inside the cover passage 11 and adapted to support the dispensing passage 6 in a centred position in the cover passage 11. More preferably there are two or more centring supports 16 and even more preferably there are three, as shown in Fig. 4 and Fig. 5. Such supports 16 may for instance be one or more sections of a rim placed around the inner perimeter of the cover passage 11, or alternatively around the outer perimeter of the dispensing passage 6.

The cover part 8 is preferably also equipped with means to connect it to a container 23 on the inside and to a closing member 19 on the outside. Thus, the part of the cover part 8 close to the inner opening 9 may for example be provided with a screw thread 26, a rim, or another usual means to facilitate fastening. A similar means is preferably provided on the outside of the cover part 8, in order to removably fasten the closing member 19. In order to make the connection between the container 23 and the cover part 8 leak-proof and spill-proof, the part of the cover part 8 close to the inner opening 9 may be widened compared to the part adapted to receive the foam- forming assembly 2, such that a rim 17a and/or a liner 17b may be provided. Upon placement of the nozzle assembly 1 on a container 23, preferably one or more of the screw thread 26, rim 17a and liner 17b is in sealing engagement with the

container 23.

Closing member & closable nozzle system

A closing member such as a cap or a lid is preferably adapted to enable leak-proof and spill-proof closing of the nozzle assembly 1.

Therefore, the invention also provides a closable nozzle system 18 comprising a nozzle assembly 1 according to the invention, and a cap 19; whereby the nozzle assembly 1 is adapted to receive the cap 19, and the cap 19 comprises a planar region 20 adapted to form a seal with the wall of the cover passage 11, and preferably also with the wall of the dispensing passage 6, upon placement of the cap 19 on the nozzle assembly 1. In this way, the seal closes off the outer cover opening 12. The planar region therefore preferably extends to at least cover the outer cover opening 12, more preferably it extends beyond the outer rim of the cover passage 11. The planar region 20 may comprise additional features to improve the seal between the cap 19 and one or both of the cover passage 11 and the dispensing passage 6. Thus, the planar region 20, preferably comprises one or more rims 21 which form a seal with the inner wall of the dispensing passage 6 and/or with the outer wall of the cover passage 11 upon placement of the cap 19 on the nozzle assembly 1. More preferably, the planar region comprises both an outer protruding rim 21a and an inner protruding rim 21b.

Alternatively, the planar region 20 comprises a protruding area 22 which forms a seal with the wall of dispensing passage 6 upon placement of the cap 19 on the nozzle assembly 1. The protruding area 22 may be an integral part of the cap 19, or a washer, liner, gasket or similarly resilient sealing means. The protruding area preferably covers at least the outlet port 7, and may hence favourably be combined with an outer protruding rim 21a. Alternatively, the protruding area may also cover the outer cover opening 12.

Container system

The closable nozzle system according to the present invention is particularly suitable for use in combination with a

container. Therefore, according to a third aspect, the

invention provides a container system for the dispensing of foam, comprising a closable foaming nozzle system 18 according to the invention, and a container 23 comprising at least one opening 24; whereby the opening 24 is adapted to receive the inner opening 9 of the cover part 8 equipped with the valved foam-forming assembly 2, such that the inner space of the container 23 is in communication with the one or more inner air inlet ports 4, and the one or more inner fluid inlet ports 5 of the foam-forming assembly 2. Both Figures 1 and 8 provide non-limiting examples of a

container system according to the invention. The container 23 preferably comprises a neck comprising the opening 24. The container is preferably equipped with a

fastening means compatible with that of the nozzle system 18. In case the container system is intended to be used for

dispensing e.g. harmful or corrosive liquids, it is

particularly preferred that the nozzle system 18 is

irreversibly connectable to the container 23, to improve the consumer safety of the system. To the same end, it is

particularly preferred that the cap 19 and the cover part 8 are provided with mutually compatible (e.g. interlocking) fastening means that are child-resistant, such as a squeeze-and-turn cap. The nozzle assembly of the invention is particularly useful for dispensing liquids, in particular clean liquids, preferably in the form of a foam, on places where good surface coverage is needed. The present invention wherein the nozzle assembly comprises both a foam-forming assembly and a cover part, may for instance usefully be designed to have a relatively narrow cover passage 11 and outer cover opening 12, making the

invention particularly useful for cleaning hard to reach surfaces such as those under the rim of a toilet bowl. The cover passage 11 and outer cover opening 12 may also be adapted in different ways (such as by making them relatively long- stretched) to enable cleaning hard to reach surfaces in other configurations, e.g. in sinks, drains or the corners of tiled surfaces .

Manufacture of the nozzle assembly

The elements of the nozzle assembly according to the invention are preferably manufactured using materials and methods well- known in the art. Preferably, the elements of the nozzle assembly are manufactured from polymer materials, more

preferably from thermoplastic polymers such as polyethylene, polypropylene, polypropylene copolymers or polypropylene random copolymers. The elements of the nozzle assembly may for instance be manufactured by injection molding.

Method and use involving the nozzle assembly

The present invention in a fourth aspect also provides a method for the leak-proof and/or spill-proof closing of a container equipped with a valved foaming nozzle assembly and optionally for the dispensing of a foamable liquid composition as

described above. Preferably, the method according to the invention also is a method for the spill-proof closing of said container. Leak- proof and/or spill-proof closing means that the assembly is closable in a leak-proof, a spill proof or a leak- and spill- proof way. A leak-proof seal or closure of the nozzle system blocks the passage of fluid from a container to the outside in the closed state. An assembly that is closed in a spill-proof way is also directed at preventing the accumulation of liquid in any dead space in the cap, when the assembly is in the closed state.

Thus, according to the method, the container system may preferably be opened and closed multiple times; it may

preferably also be used to dispense liquid, possibly multiple times, when the container is in the opened state.

As described above, the invention, in a fifth aspect, also provides use of a cover 8 to provide a leak-proof closable container system comprising a valved foam-forming assembly 2. Preferably, this use according to the invention relates to use to provide a closable container system that is also spill-proof closable .

Claims

1. Nozzle assembly (1) comprising

a valved foam-forming assembly (2), comprising

• one or more outer air inlet ports (3) ,

• one or more inner air inlet ports (4),

• one or more inner fluid inlet ports (5) , and

• a dispensing passage (6) comprising an outlet port (7),

• wherein the outlet port (7) is located away from the outer air inlet ports (3) , as defined herein; a cover part (8) comprising

• an inner opening (9)

• an inner space (10) and

• a cover passage (11) comprising an outer cover opening ( 12 ) ,

characterised in that

the inner space (10) of the cover part (8) is adapted to receive the valved foam-forming assembly (2), whereby upon receiving

• the dispensing passage (6) is substantially concentric with the cover passage (11),

• such that the area (C) of the outer cover opening (12) outside outlet port (7) is in communication with the one or more outer inlet ports (3) .

2. Nozzle assembly according to claim 1, whereby the area (C) of the outer cover opening (12) outside outlet port (7) forms an annular opening (14)

3. Nozzle assembly according to claim 1 or 2 wherein the outlet port (7) is located at a shortest distance along the outer surface of the foaming nozzle assembly (2) of at least 2 times the diameter of the outlet port ( 7 ) .

4. Nozzle assembly according to claim 3 wherein the outer air inlet ports (3) are located in the base plane (15) which the dispensing passage (6) protrudes from.

5. Nozzle assembly according to any one of claims 1 to 4 wherein the outer cover opening (12) is essentially circular .

6. Nozzle assembly according to any one of claims 1 to 5 wherein the cover part (8) is adapted to receive the foam-forming assembly (2) such that the dispensing passage (6) is centred in the cover passage (11) .

7. Nozzle assembly according to claim 6 wherein one or more centring supports (16) are provided inside the cover passage (11) adapted to support the dispensing passage (6) in a centred position in the cover passage (11) .

8. Closable nozzle system (18) comprising

a nozzle assembly (1) according to any one of claims 1 to 7, and

a cap (19) ; whereby the nozzle assembly (1) is adapted to receive the cap (19), and

the cap (19) comprises a planar region (20) adapted to form a seal with the wall of the cover passage (11) upon placement of the cap (19) on the nozzle assembly (1) .

9. Closable foaming nozzle system (18) according to claim 8, whereby the planar region (20) is adapted to also form a seal with the wall of the dispensing passage

(6) upon placement of the cap (18) on the nozzle assembly ( 1 ) .

10. Closable foaming nozzle system (18) according to claim 8, whereby the planar region (20) comprises one or more rims (21) which form a seal with the inner wall of the dispensing passage (6) and/or with the outer wall of the cover passage 11 upon placement of the cap (19) on the nozzle assembly (1) .

11. Closable foaming nozzle system (18) according to claim 8, whereby the planar region (20) comprises a

protruding area (22) which forms a seal with the wall of dispensing passage (6) upon placement of the cap (19) on the nozzle assembly (1) .

12. Container system for the dispensing of foam comprising a closable foaming nozzle system (18) according to any one of claims 8 to 11, and

a container (23) comprising at least one opening (24); whereby the opening (24) is adapted to receive the inner opening (9) of the cover part (8) equipped with the valved foam-forming assembly (2), such that the inner space of the container (23) is in communication with the one or more inner air inlet ports (4), and the one or more inner fluid inlet ports (5) of the foam-forming assembly (2) .

13. Method for the leak-proof closing of a container

equipped with a valved foam-forming nozzle assembly and optionally for the dispensing of a foamable liquid composition comprising the steps:

a. providing a container system according to claim 12; b. filling the container (23) with the foamable liquid composition;

c. connecting the cover part (8) equipped with the

valved foam-forming assembly (2) to opening (24); d. closing the outer cover opening (12) by applying the cap (19) ;

e. optionally opening the outer cover opening (12) by removing the cap (19);

f. after opening the outer cover opening (12),

optionally increasing the pressure inside the container (23) thereby dispensing at least part of the foamable liquid composition from the container (23) via the nozzle assembly (1); and

g. optionally repeating steps (d) and (e) and/or (f) .

14. Use of a cover (8) to provide a leak-proof closable container system according to claim 12.

15. Use according to claim 14, to provide a closable container system that is also spill-proof closable.