HK1154470B - Exchangeable filter for beverage production device and beverage production device comprising such filter - Google Patents

Description

Replaceable filter for a beverage production device and beverage production device comprising such a filter

Technical Field

The present invention relates to a filter for use with an apparatus for providing ready-to-drink nutritional compositions, such as infant formula. More particularly, the present invention relates to a replaceable filter card that is removably insertable into a device to facilitate increased hygiene levels and to facilitate servicing of the device.

Background

Infant formula has been developed as an alternative to breast milk in order to provide the required nutrition to the infant. Generally, infant formulas are based on cow's milk or soy milk and may be provided in different forms, such as powder form or concentrated liquid form.

Each different form in which infant formula may be provided has their own advantages. For example, although infant formula provided in powder form has relatively high nutritional quality, its preparation is considered inconvenient and time consuming, since water that has been boiled in advance and can be cooled must be poured into a sterile drinking container containing the powder in order to prepare the liquid infant formula. Infant formulas in concentrated liquid form present the same inconvenient dispensing process.

Powdered infant formula, if prepared and consumed in this manner, provides a safe and nutritious alternative to breast milk. However, many parents or caregivers do not properly prepare such food, primarily due to inconvenient compounding, thereby exposing the infant to the risk of infection or other risks. For example, if the water is not properly disinfected prior to use or if the final compounding has been compounded too long in advance, there may be a risk of germs being transmitted to the infant. Typically, water sources are safe in developed countries, but may not be so anywhere.

In a further development, single serving prepared infant formulas have been introduced which overcome the inconvenience of preparation of infant formulas. However, these ready-to-eat products are more expensive than infant formulas stored in bulk, and they often have the disadvantage that once a serving is opened, it must be consumed immediately to avoid the risk of bacterial contamination. Furthermore, even single serving infant formulas are reconstituted with water (recanstitute). Thus, there is a risk that water may not necessarily be properly sterilized and that a separately provided baby bottle is prepared and stored in large quantities in advance.

The immune defenses of infants and children are generally not fully mature and, therefore, these populations are particularly vulnerable to bacterial and viral infections. For example, they may be infected in an environment where the immune system of a healthy adult can resist the infection, or they may suffer more serious consequences than a healthy adult due to the infection. Similar difficulties may arise in populations where the immune system is compromised, such as the elderly. The result is that a device equipped with a nutritional composition that is safe for healthy adults may not be able to produce a product that meets the increased safety standards required for products to be consumed by subjects with immature or compromised immune systems.

Therefore, there is a need for a method or apparatus that can provide nutritional compositions, such as infant formula, in a convenient and safe manner.

WO2006/077259 discloses a method for preparing a single serving of a nutritional composition comprising introducing a liquid such as water into a cartridge containing a unit dose of the composition in concentrated form. Thus, the water is treated prior to introduction into the cartridge to facilitate removal of pathogens from the water. Such treatment may be for example preheating of the water, filtering or irradiation with uv light.

A device teaching the principle of treating water through a filter, which is used for the preparation of a nutritional composition from a cartridge in a Dispenser, is disclosed in co-pending european patent application No.06117801.8 entitled "dispensing for preparation and use composition", filed on 25.7.2006. Thus, a convenient solution for treating water may be provided in order to ensure that the water is germ-free. However, the filter in the disclosed apparatus is incorporated into the drain.

In order to ensure a high standard of safety in terms of the removal of any germs that may be contained in the liquid used for the preparation of the nutritional composition, the filter of such a device provided has to be replaced repeatedly. Accordingly, there is a need for an improved filter system that enables the filter to be replaceable and/or can be serviced to provide the necessary levels of hygiene and food safety.

US20070199888 relates to a water filter for a coffee machine having a tab for attachment to a brew basket of the machine. However, such water filters are only slidably engaged beneath a brew basket that receives water at atmospheric pressure. Such filters are said to have a thickness of a few millimetres. However, the filter is not intended for removing germs to treat water.

WO01/50875a1 relates to a drip coffee brewer (drip coffee brewer) comprising a liquid reservoir connected to a heater and a liquid outlet disposed above a support means holding a filter assembly. The filter assembly is designed for removing pathogens. The filter is provided with a reservoir to be able to receive dripping water collected against the filter. Such systems are designed to slowly filter water at atmospheric pressure through the principle of percolation. In addition, the filter assembly requires a complex filter structure including an adsorbent support mesh substrate having a surface to which a mixture of adsorbent particles and binder particles are fused.

Disclosure of Invention

The present invention addresses the above-mentioned problems. The present invention is also directed to other objects and particularly to solutions to other problems as will occur in the remainder of the specification.

In particular, the present invention aims to provide a solution for supplying water free from undesired microorganisms at a certain pressure (above atmospheric pressure) and flow rate in a device for preparing a nutritional composition for effective interaction with ingredients.

In a first aspect, the invention proposes a device for preparing a nutritional composition by supplying water to ingredients provided to the device,

the apparatus comprises: means for putting the fluid under pressure, such as a pump, connected to an integrated or external water supply,

a drain end for providing water into a cartridge containing an ingredient to effect interaction of the water and ingredient in the cartridge, wherein the pump and drain end are in water communication via a water flow path, whereby the pump can supply water at a pressure above atmospheric pressure through the water flow path,

a rigid filter assembly comprising at least one antibacterial/antimicrobial filtration membrane and a filter packaging means, wherein the filter assembly and filter packaging means are complementarily configured such that the filter assembly can be inserted into the filter packaging means in a fluid-tight manner across the water flow path prior to the drainage end and can be removed from the filter packaging means.

With the device according to the invention, it is possible to enable the interaction of the water supplied to the device, in particular by means of the pump connected to the water supply, with the ingredients contained in the cartridge. Thus, the water is preferably provided to the drain end by a water supply means arranged upstream (e.g. on the upper side) of the cartridge receiving chamber. It should be noted that the term "water supply" also includes the water supply line of the apparatus, which may be connected to external tap water or stored water outside the apparatus itself.

In the present invention, water is introduced into the cartridge through the needle, preferably at a flow rate of 100-. This forms a spray jet with sufficient energy to dissolve the ingredients in the cartridge. The filtration membrane of the antimicrobial filter may be selected based on the pressure drop across the membrane within the water flow path. The lower the pressure drop across the filter, the higher the energy of the fluid ejected and therefore the faster the contents dissolve in the cartridge.

The outlet is preferably arranged downstream, for example on the underside of the discharge end. Thus, after interaction of the water with the ingredients in the cartridge, the output of the nutritional composition to be prepared takes place downstream, for example on the underside of the draining end, thereby enabling the flow of the nutritional liquid composition into a receptacle, for example a cup or container that can be placed under the cartridge.

In another preferred embodiment, a filter device may also be provided downstream of the drain end. Thus, the filter may be used to filter dissolved infant formula formed as a result of the introduction of water into the cartridge. Accordingly, any germs in the infant formula may be removed. Since the final flow of liquid expelled by the cartridge is not subjected to high pressures, means may be provided to enable a predetermined flow rate through the filter. For example, the surface of the filter may be enlarged or pressure may be exerted on the final flow of liquid flowing from the cartridge by a dedicated pump or the like.

A rigid filter assembly provided to the water flow path between the pump and the discharge end is provided with at least one antimicrobial filter membrane as a physical barrier to control the permeability to microorganisms, in particular to block the passage of bacteria or germs that may be present in the supplied water. Thus, a safe preparation of the nutritional composition may be ensured.

In a preferred embodiment, a cartridge may be provided containing the ingredients for which the nutritional composition is prepared. The cartridge is received in a cartridge receiving chamber of the device. The pod is preferably a disposable pod containing a dose of the nutritional composition to be hydrated (e.g. diluted, dispersed and/or infused with water). Thus, the water provided to the pod may be used to reduce the nutritional composition. The cartridge preferably comprises a water injection surface and an output surface.

In a possible "direct flow" airtight cartridge mode, preferably as described in european patent EP1472156B1, or finally also in other modes such as in international patent application WO2007131559, pressure is generally built up inside the cartridge during the water spray, which causes the lower face (or partition) of the cartridge to open, thereby enabling the outflow of the liquid to be dispensed. Since the outflow of the beverage to be prepared takes place under the cartridge, without coming into contact with the opening means of the device, it is possible to pour the flow of liquid directly into the receptacle, for example into a baby bottle, without contaminating the surface of the device. This results in a very hygienic preparation and delivery of the nutritional formulation.

After the water is sprayed into the cartridge, the pouring from the cartridge may be delayed in order to provide sufficient time for the interaction of the water with the ingredient, for example to achieve complete dissolution of the ingredient in the water. For pouring of the beverage to be prepared from the cartridge, opening means, such as projections, can be provided against a tearable output sheet in order to tear the membrane in a controlled manner. These opening means interact with the flakes in response to a pressure rise generated in the cartridge upon water spraying. The nutritional composition to be prepared may then be made to flow from the dedicated outlet of the cartridge directly into the receptacle without contacting the device.

EP1472156B1 discloses various suitable cartridge configurations that can be used in the device of the present invention.

The use of a new disposable cartridge for the preparation of nutritional products, combined with the special "straight flow" characteristics of said cartridge, i.e. including in said cartridge an opening technique responsive to the internal pressure and draining the liquid directly from said cartridge into a receiving container such as a baby bottle, thus greatly facilitates the preparation of the nutritional product, as well as making the preparation significantly safer, greatly reducing or even eliminating the risk of contamination.

It is particularly advantageous if the apparatus is used in a hospital care room which is not only used for preparing infant formula for healthy infants, but also for preparing infant formula for infants with a particular disease, defect or severe allergy, for example to cow's milk.

Furthermore, the device may be provided with means for adjusting the amount and/or temperature of water to be dispensed into the cartridge, so as to stop the flow of water when a preselected or automatically controlled amount has been dispensed. The water regulating means may comprise a water pump, a control unit of the device containing the program, a cartridge recognition system between the cartridge and the device, such as a bar code and the like on the cartridge, for suitably controlling the physical conditions of the water delivered with respect to the type of cartridge.

The device may further be provided with cleaning means to empty the cartridge of residual liquid, for example by flushing the liquid in the cartridge with gas. The cleaning device also reduces the risk of contamination of the nutritional composition back into the apparatus. A suitable gas is compressed air at a pressure between 200 and 2 bar, for example 300 bar, which may be pressurised by an air compressor in the apparatus.

Since the filter assembly is designed to be inserted into or removed from the device, the used filter assembly can be replaced with a new filter upon indication by the user or, for example, in response to an alarm signal (e.g., an LED flash on the device or an indication on an LCD screen). These indications may be triggered when a particular serving size has been provided (formulation) or a particular volume of water has flowed through the filter assembly. The replacement signal may also be triggered by a sensor measuring the flow through the filter or the pressure above and/or below the filter. Alternatively, the filter assembly may be recycled by performing a suitable heat treatment, e.g. sterilization, on the filter assembly outside the dispenser, e.g. according to a user instruction. Thus, the filter device can be removed without effort for replacement or recycling after a certain determined time in order to ensure proper water filtration conditions in the apparatus and thus a safe water supply to the apparatus. However, it is also possible to sterilize the filter in the machine by means of a steam generator provided.

Preferably, the filter assembly connected to the apparatus comprises a frame for housing at least one antimicrobial filter membrane. By antibacterial filter membrane is meant, among other things, a filter designed for filtering germs or undesired microorganisms (such as bacteria, viruses, yeasts and/or fungi or other particles) from the water to be filtered. The antimicrobial filtration membrane can have a nominal pore size of 0.45 microns or less. A particularly preferred nominal pore size is between 0.01 and 0.45 microns. For filtering bacteria, the nominal pore size may be between 0.1-0.3 microns, most preferably about 0.2 microns. For filtering viruses, the pore size may be reduced to 0.05 microns or less. When pathogen removal is less critical, a more porous membrane may be selected if a higher flux is desired.

For use with the present apparatus, a polymer membrane such as a laminated hydrophilic PES (polyethersulfone) membrane produced by Pall corporation of Switzerland or any other thin filtration membrane (e.g. Millipore filtration membrane) made, for example, of a polymer having comparable specification characteristics may be used. An antibacterial filter membrane made of a plastic material is preferred. The preferred thickness is less than 2 μm, more preferably less than 1 μm. Preferably, the filter assembly comprises one or more of these membranes. Preferably, the antimicrobial effect is achieved by filtration, not for example by adsorption such as by activated carbon. The effect is that the filter (compared to activated carbon) is easier to regenerate.

By using such a filter, the risk of contamination of the nutritional composition to be dispensed can be significantly minimized.

Since thin antimicrobial filtration membranes are physically sensitive and not easily handled, the filter assembly preferably includes a water permeable backing means (backing means) preferably disposed adjacent to support the antimicrobial filtration membrane. The backing means may for example be at least one perforated wall abutting the filter membrane and extending across the flow path direction on the downstream side of the filter assembly so as to at least partially support the surface of the filter membrane. Accordingly, it is possible to effectively prevent breakage and/or deflection of the filter assembly when water passes through the filter assembly. Most preferably, a second perforated wall is provided adjacent the membrane, extending across the direction of the flow path, to further support the membrane at the upstream side of the filter assembly. The perforated wall may for example be formed by a plurality of ridges or a grid.

Furthermore, in case the filter is clogged, the pressure difference across the filter membrane may rise from about 0.1 bar to 10 bar. In this case, the backing means may provide protection to the filter membrane in order to prevent rupture of the membrane. The backing means also provides protection to the film when it is handled and inserted into the device.

In order to ensure fluid tightness between the filter assembly and the water path of the apparatus, sealing means are provided at the interface of the filter assembly and the apparatus. Preferably, the sealing means are located around the filter section of the filter assembly and/or the outlet and inlet of the channel. The sealing means may be part of the water communication channel of the dispensing device and/or part of the filter assembly. One possible sealing material is Santopren or Thermolast K. Preferably, a lip seal is provided which enables a watertight fit of the filter to the device under high pressure.

The device further comprises a steam generator connected to the fluid communication path to facilitate cleaning of the filter assembly and other surfaces in contact with water, such as the tubing, drain end and cartridge receiving chamber of the device. Thus, the filter is manufactured and assembled to withstand steam up to, for example, 120 ℃. Accordingly, corresponding materials are selected, such as PP for the rigid frame of the filter assembly and Santopren for the seal.

The filter assembly for the device may preferably be removed from or inserted into a hole provided in an easily accessible location. The aperture is preferably provided on one face of the device, for example the top face of the device. Thus, the replaceability of the filter assembly is significantly enhanced, since any user can perform the replacement of the filter assembly.

Multiple use of the same filter membrane should be prevented because the filter does not have the same characteristics after a long period of use. Thus, an element may be installed on the filter assembly and/or the apparatus to prevent multiple uses of the same filter membrane. For example, a bar code may be individually marked for each filter membrane and memorized by the device. Another possibility is to have an element on the filter assembly that breaks when the filter is removed and prevents a new mechanical insertion or to utilize a sensor on the device.

When the filter assembly is fully inserted into the corresponding aperture on the device, the filter assembly may be locked by locking means provided on the filter assembly and/or the device. For example, a snap-fit feature may be provided on the filter assembly that interacts with a male or female element provided adjacent the aperture of the device when the filter assembly is fully inserted into the aperture. When the user desires to remove the filter assembly from the appliance, the user may release the snap so that the filter assembly may be removed from the aperture of the appliance. The filter assembly may also be locked in the aperture by friction applied to the filter assembly by abutting faces inside the aperture when the filter assembly is connected to the device. The frictional force may also be applied by a sealing means of the filter assembly and a corresponding face within the bore abutting the sealing means when the filter is inserted into the bore. When inserting the filter assembly into the aperture, the user must apply a certain force in order to overcome the frictional force in order to fully insert the filter assembly into the aperture. The same applies to the removal of the filter assembly from the aperture. Hereby, a locking of the filter card in the device is achieved, the filter assembly being connectable to the device in a stable and secure manner.

In another preferred embodiment, the closing mechanism comprises at least two enclosing members movable relative to each other to enclose the filter assembly. Accordingly, when a filter is to be placed in a corresponding aperture in the device, the user operates the closure mechanism so as to enable relative movement of the enclosing members to enclose the filter assembly located within the aperture. Therefore, when the enclosing members are brought close together, the filter assembly located between the enclosing members can be effectively enclosed. Accordingly, the filter assembly may be held in a fixed and stable position during operation of the apparatus. For this purpose, a stem can be provided on the housing of the device, said stem being connected to at least one of the enclosing members. In this way, a user may encapsulate and/or unclamp the filter assembly between the encapsulating members by operation of the lever. Of course, the packaging of the filter assembly may be automated. Thus, a button may be provided on the housing of the device, which button is capable of operating a dedicated motor allowing relative movement of the at least one enclosing member to enclose and/or release the filter assembly in the aperture.

In addition, a proximity sensor may be provided at the bottom of the well to facilitate detection of the presence of the filter. Wherein the proximity sensor is connected to said pump of the device. Thus, the pump is preferably only operable when the proximity sensor detects the presence of the filter. Thus, a safe operation of the system is enabled, since the device can only be operated when the filter assembly is fully inserted into the aperture of the device.

The nutritional composition provided by the device according to the invention may be any composition which is intrinsically very sensitive to contamination by pathogens. Examples of preferred nutritional compositions for use in the method of the invention are infant formula, growing up milk and liquid infant cereals. The ingredients of the composition are not critical to the process of the present invention and other food powders or liquid concentrates may be used. Examples of different types of infant formulas that may be used in the method of the invention include formulas containing primarily whey protein, formulas containing a mixture of whey and casein, formulas based on other proteins (e.g. soy), formulas in which the protein component is partially or extensively hydrolyzed, and the like. The nutritional composition is preferably stored in powder form or concentrated liquid form in an air-impermeable disposable cartridge disposed within the chamber.

Ready-to-drink nutritional compositions may also be prepared according to the method of the invention using more than one pod to prepare a serving (ready-to-drink nutritional composition). This allows for some flexibility in the composition that is formulated. For example, a kit/cartridges containing different supplements may be manufactured and the consumer may be provided with instructions to combine these to formulate a personalized composition suitable for the particular needs of the recipient.

In a second aspect, the invention proposes a filter card for connection to an apparatus for preparing a nutritional composition, said filter card comprising a frame for holding in place at least one antimicrobial filter membrane and at least one rigid, water-impermeable backing member for supporting said filter membrane. The backing member may be arranged adjacent or proximate to the filter membrane. The backing members may be perforated with small holes, but the holes have a diameter large enough to minimize pressure drop at the members.

With the filter card according to the invention, the required water filtering function can be provided to the device in a more convenient and safer way. In particular, the replacement of the filter device by means of the filter card can be operated by any user. Furthermore, the rigidity of the frame of the card makes it easy to handle and protect the membrane, which is easily broken and intrinsically unstable in shape, and to ensure correct positioning of the card in the device.

In addition, perforated backing members disposed adjacent the antimicrobial filter membrane support the filter membrane to maintain its integrity (e.g., avoid tearing, collapsing, deflecting, or wrinkling) under the pressure of water. Thus, the perforations preferably have a larger diameter (e.g. 0.6mm) than the micro-pores of the filter membrane. So that water passing through the filter card is not deflected by the backing members, the filter membrane can withstand high liquid flows without risking deflection and/or rupture of the filter membrane.

Preferably, the frame of the filter card is made of a rigid plastic and/or metal material.

The filter membrane is preferably a flat membrane, as already described, having a nominal pore size comprised between 0.01 and 0.45 micron, most preferably between 0.1 and 0.3 micron. Thus, pathogens present in the water used for the preparation of the nutritional composition may be blocked in the membrane. It is noted that the membrane is asymmetrically designed such that it may comprise a varying micro-pore cross-section in the flow direction through the membrane, thereby defining an inlet filtration side and an outlet filtration side of the membrane. In particular, the micropores become larger from the inlet side to the outlet side.

In another preferred embodiment, at least one antimicrobial filter membrane is sandwiched between at least two perforated backing members. Wherein the perforations of the backing member may be aligned so that water guided through the perforations is not deflected. Furthermore, the perforations preferably have a larger diameter than the pores of the filter membrane. So that water passing through the filter card is not deflected by the backing members. It is thus believed that the flow resistance created by these perforations of the backing member is lower than the flow resistance of the micropores of the membrane.

However, it is also possible to provide an embodiment of the filter card in which two or more perforated backing members with aligned perforations are arranged on each side of the filter membrane. The upstream backing members disposed adjacent the first filter membrane preferably have perforations of smaller diameter than the downstream backing members. The outer backing member is thus designed such that no deflection of water occurs when water passes through the filter card. The downstream backing member may support the second filter membrane. Accordingly, a filter card may be provided which can withstand a high pressure drop across the filter card when connected to a water flow path. Preferably, the pressure drop across the filter device in the water flow path is less than 1 bar.

Furthermore, the filter card preferably comprises sealing means for ensuring that the filter is watertight when connected to the device, in particular for avoiding water from flowing past the filter card. Thus, the sealing means prevents leakage from the water flow path in which the filter card is inserted, when water passes through the filter card.

Furthermore, the perforated backing members of the filter card may be designed such that they can be supported by support members of the device to which the filter card is connected. For example, support regions may be provided on the surface of the backing member. In this way, a support member connected to the device may be designed to abut on the support area in order to provide additional support to the filter card against deflection and/or rupture. Thus, a stable and fixed position of the filter card within the water flow path may be ensured.

Preferably, the filter card further comprises guide means connected to the frame of the filter card. The guide means may be asymmetrical so that the filter card can only be inserted into the device through one predetermined side. The guide means may be a projection on only one side of the frame or alternatively a recess which fits into a corresponding recess or alternative projection in the aperture of the device into which the filter card is insertable. This asymmetric card structure ensures that the filter card is effectively prevented from being inserted by the user in the wrong way. Since the filter membrane can be designed asymmetrically as described above, it is important to take care of the correct insertion side of the card.

Furthermore, the filter card may be equipped with locking means in order to ensure a secure and stable connection between the filter card and the device to which the filter card is connected. For example, a snap-fit feature may be provided on the filter card that interacts with a male or female element provided adjacent to the aperture when the filter card is fully inserted into the aperture of the device. Thus, when a user desires to remove the filter card from the device, the user may release the clasp so that the filter assembly may be removed from the aperture of the device.

Furthermore, it is important to ensure that the water to be filtered flows through the filter membrane and does not flow sideways through its outer edge. Thus, a sealing means is provided between the backing means and the filter membrane. The sealing means may comprise a plastic sealing material provided to the outer edge of the filter membrane by an overmolding process. Optionally, an O-ring may be provided in the assembly to prevent water from flowing past the filter membrane. In case O-rings are used, the filter membrane should be unidirectional to avoid radial water flow through the membrane and by-pass it by capillary action.

Drawings

Further features, advantages and objects of the present invention will become apparent to those skilled in the art after understanding the following detailed description of embodiments of the invention in conjunction with the accompanying drawings.

Fig. 1 shows a schematic view of a preferred embodiment of an apparatus for preparing a nutritional composition according to the present invention.

Figure 2 shows a perspective view of a preferred embodiment of a filter card according to the present invention.

Figure 3 shows an exploded assembly view of one preferred embodiment of the filter card connected to the water flow path.

Figure 4 shows a cross-sectional view of one preferred embodiment of a filter card connected to a water flow path.

Figure 5a shows a preferred embodiment of the backing member in a top view.

Figure 5b shows a cross-sectional view of one preferred embodiment of the backing member according to line a-a of figure 5 a.

Figure 6 shows a cross-sectional view of a preferred embodiment of a filter card equipped with a filter membrane sandwiched between two backing members.

Figure 7 shows a cross-sectional view of another preferred embodiment of a filter card equipped with O-rings.

Figure 8 shows an exploded assembly view of another preferred embodiment of a filter card in which the backing member is formed as an integral part of the filter card frame.

Figure 9 shows a preferred embodiment of the packaging mechanism designed to fix the position of the filter card in the dedicated hole of the device.

Detailed Description

Fig. 1 shows a schematic view of a preferred embodiment of the device according to the invention. The apparatus comprises a water supply 1 connected to a water pump 2. The output of the pump is connected to a heater 3, the heater 3 preferably comprising a coiled stainless steel tube in a moulded aluminium heating block (not shown). Providing power to the heating block sufficient to heat the water to a desired temperature as it passes through the tube. The output of the heater is connected to a filter 5, the filter 5 being connected to the discharge or spray end 4 of the apparatus. The discharge end 4 comprises a chamber 9 for receiving the cartridge 7. The term "pod" refers in the general idea of the invention to a disposable package, such as a pod (pod), capsule or sachet of various packaging materials containing a nutritional composition.

The term "pump" means any technical device that can deliver liquid from a water supply to a spraying end with a sufficient positive pressure. The device may be a pressure pump such as a piston pump, diaphragm pump, peristaltic pump, gear pump, centrifugal pump, progressive cavity pump, hand pump, or the like.

Furthermore, a flow control device 2a is preferably provided between the pump 2 and the heater 3 of the apparatus. Further, a temperature control device 3a is preferably provided between the heater 3 and the discharge end 4. Thus, the temperature and flow rate of the liquid within the device can be controlled and regulated.

Furthermore, an air pump 6 is connected to the discharge end 4 so as to be able to flush any residue inside the cartridge 7 into a receptacle provided below the cartridge 7.

The cartridge 7, which is only schematically shown, contains about 10ml of ingredients. These ingredients are preferably provided in the form of a powder or a concentrated liquid within said cartridge 7. The preparation of a 100ml portion of a nutritional beverage such as an infant formula using the apparatus according to the invention will now be described.

The cartridge 7 is positioned in a cartridge receiving chamber 9 of the discharge end 4 such that an injection element (not shown) projecting into the chamber 9 penetrates a membrane sealing the cartridge 7. The flow control means 2a and the temperature control means 3a are set so as to provide the required amount of water to the cartridge at the required temperature. Therefore, water is preferably pumped from the water tank 1 (or from an external water supply line) to said heater 3 at a pressure of about 0.2 bar, the water being heated in said heater 3 to a preferred temperature between 25 and 40 ℃. The heated water is then passed through the filter 5 to the chamber 9 of the discharge end 4 at a preferred pressure of between 2 and 7 bar and dispensed from the chamber 9 into a cartridge 7 containing a unit dose of a nutritional composition such as an infant formula. When the pressure in the cartridge 7 reaches a predetermined value, preferably 2.5 bar, the cartridge opens and reconstituted infant formula is dispensed from the cartridge directly into a suitable receptacle (not shown), such as a baby bottle. The air pump 6 is then operated to flush any residual liquid out of the cartridge and into the receptacle.

Furthermore, a steam generator 8 is connected to the discharge end 4 and the filter 5. In operation, the chamber 9 of the discharge end 4 and the filter 5 can be sterilized as often as desired by passing steam from the steam generator through the discharge end 4 and the filter 5.

Fig. 2 shows a preferred embodiment of a filter card 20 according to the invention. The filter card 20 comprises a frame 21 designed for accommodating a filter membrane 30 (shown in figure 3) and at least one rigid perforated backing member 24. The frame 21 is preferably made of a rigid plastic or metal material and is equipped with semicircular ends 21a, the semicircular ends 21a being the ends to be first introduced into holes provided on the device and designed to receive the filter cards 20, such as slits. Thanks to the semicircular end portion 21a, the filter card 20 can be easily inserted into the slit provided in the device, even if the user inserts the filter card 20 in an inclined manner or offset from the central axis of the hole.

Furthermore, the filter card 20 comprises guiding means 22 to prevent the user from inserting the filter card 20 into the provided slot with an incorrect side. Preferably, said guide means 22 are at least one projecting ridge provided on one of the edges of the filter card 20, said projecting ridge being designed to be received by a corresponding groove 22a (shown in fig. 3) provided at the hole of the device designed for the insertion of said filter card 20. Preferably, the guide 22 is an integral part of the frame 21.

As shown in fig. 3, the frame 21 comprises a preferably circular aperture 23 for receiving the filter membrane 30 and at least one perforated backing member 24. More preferably, the at least one filter membrane 30 is arranged or sandwiched between at least two backing members 24 positioned in parallel and in close contact with the filter membrane 30. Furthermore, the backing members 24 are perforated in order to enable fluid to flow through the filter membrane 30 and thus through the filter card 20. The diameter of the perforations of the backing members 24 is preferably larger than the nominal pore size of the provided filter membrane 30. Thus, the flow resistance of the backing members 24 does not affect the overall flow resistance of the filter card 20 in a negative way. Furthermore, in the case of two or more perforated backing members 24 being provided to the filter card 20, the arrangement of the backing members 24 is adjusted such that the perforations of the backing members 24 are aligned. Therefore, water passing through the filter card 20 is not biased.

The backing members 24 are preferably designed to be supported by support members 25a (shown in figure 3) of the device to which the filter card 20 is to be attached. The support members 25a may be, for example, ridges or the like, which are designed to abut against the backing members 24 when the filter card 20 is connected to the device. Thus, the surface of the backing member 24 comprises a support area 25, on which support area 25 the support member 25a can abut. The support areas 25 are preferably evenly distributed over the surface of the backing member 24. The support area 25 does not comprise any perforations so that support members 25a abutting on the support area 25 do not deflect any water passing through the perforations of the backing members 24. Thus, the support areas 25 of the backing members 24 abutting on a particular support member 25a enable a stable position of the filter card 20 when the filter card 20 is connected to a device for preparing a nutritional composition. The risk of deflecting or rupturing the filter card 20 or in particular the filter membrane 30 when water passes through the perforations of the backing members 24 at high pressure can thereby be effectively minimized.

Furthermore, the protection of the filter membrane 30 against deflection or rupture of water as it passes through the filter card 20 may be enhanced by providing one perforated backing member 24 of sufficient rigidity to each side of the filter membrane 30. Wherein those backing members 24 on the outer side on each side of the filter membrane 30 have a larger diameter than those backing members 24 on the inner side arranged in close contact with the filter membrane 30. Thus, those backing members 24 on the outside do not deflect liquid passing through the backing members 24 and through the filter membrane 30. Furthermore, in order to enable the water flow to pass through the filter membrane 30 and the backing members 24, the perforations of all backing members 24 arranged on each side of the filter membrane 30 are arranged in alignment.

Furthermore, the filter card 20 comprises sealing means 26 for sealing the filter card 20 when the filter card 20 is connected to the water flow path 50 (shown in fig. 3). The sealing means 26 are arranged at the aperture 23 of the frame 21. Preferably, said sealing means 26 is an O-ring or the like, adapted to seal said hole 23, and therefore said filter card 20, when water passes through the filter card 20. The sealing means 26 are preferably arranged on each side of the filter card 20. The sealing means 26 may also be provided on the water flow path 50 to which the filter card 20 is to be connected. As shown in the figures, the sealing means is preferably a lip seal. The lip seal is particularly advantageous because the pressure acting on the lip seal enhances the sealing effect by pressing the lip towards the counter part. Thus, the higher the pressure in the filter chamber, the higher the pressure pressing the lip against the counter part. So that the preferred embodiment according to the figure can withstand pressures of, for example, up to 16 bar without leakage.

Furthermore, the sealing means 26, backing members 24 and filter membrane 30 are designed to be easily removable from the aperture 23 of the filter card 20. Thus, fastening means 27 are provided which can be connected to said holes 23 of the filter card 20 (see fig. 2). Wherein said fastening means 27 preferably encapsulates the filter membrane 30, the backing member 24 and the sealing means 26. Said fastening means 27 are preferably clamps or the like, designed to be connected to said holes 23. Of course, the fastening means may also be provided as an integral part of the aperture 23. Thus, the user can easily replace the filter membrane 30, the backing member 24 or the sealing device 26 when the filter card 20 is not connected to the designated water flow path 50. So that the filter membrane 30 can be repeatedly replaced in a convenient manner to enhance the protection provided by the filter card 20 against pathogens.

Fig. 3 shows an exploded assembly view of a preferred embodiment of the filter card 20 connected to the water flow path 50. Wherein two enclosing members 40a, 40b are connected between the water flow paths 50 to enable connection between the water flow paths 50 and the filter card 20. The two enclosing members 40a, 40b enclose a hole 42 formed by their surfaces 41a, 41b, into which hole 42 the filter card 20 can be inserted. In this way, said semicircular end 21a of the filter card 20 abuts on the semicircular recess 21b of the bottom of said hole 42 enclosed by the two enclosing members 40a, 40 b.

Furthermore, a linear groove 22a is preferably provided on one side of the hole 42, preferably on one of the two enclosing members 40a, 40 b. The linear groove 22a is designed to receive a ridge 22 formed on one side of the filter card 20. So that the filter card 20 can only be inserted with the correct side into the hole formed by the two enclosing members 40a, 40 b.

Each of the two enclosing members 40a, 40b comprises a circular recess 51 in its interior which is concentrically arranged and connected to the water flow path 50. Thus, the diameter of the water flow path 50 may be matched to the diameter of the filter membrane 30 provided at said aperture 23 of the filter card 20. Accordingly, the entire surface of the filter membrane 30 provided on the filter card 20 may be used to filter water. These recesses 51 are sealed by sealing means 26 provided at said frame 21 of the filter card 20, when water passes through the water flow path 50 and thus through these recesses 51. Of course, the sealing means 26 may also be provided on the enclosing member around these recesses 51.

As can be seen from fig. 3, a support member 25a is provided within said recess 51 of the enclosing members 40a, 40 b. These support members 25a are preferably cylindrical protruding ridges which abut on support areas 25 provided at the perforated backing member 24 when the filter card 20 is inserted into said hole 42 enclosed by the two enclosing members 40a, 40 b. Thus, deflection and/or rupture of the perforated backing members 24, and thus also of the filter membrane 30, can be effectively prevented.

The enclosing members 40a, 40b are movable relative to each other in order to completely enclose the filter card 20 within the aperture 42 and secure its position. Thus, after inserting the filter card 20 into the hole 42, the two enclosing members 40a, 40b can be brought closer together and the position of the filter card 20 is fixed in a stable position and in a watertight manner in the hole 42. In the same way, the release of the filter card 20 can be achieved by moving the two enclosing members 40a, 40b away from each other. To enable relative movement of the enclosing members 40a, 40b, at least one of the enclosing members is connected to a closing mechanism (not shown), such as a lever or a motor that can be operated by a user.

In the event that the filter card 20 is detached from the device by moving the enclosing members 40a, 40b away from each other, the remaining water in the water flow path 50 and the circular recess 51 upstream of the filter is released in a controlled manner through the opening 51a provided at the bottom of the hole 42. A collector (not shown) below the opening 51a is connected to a drip tray (not shown) so that fluid can be drained from the apparatus.

Furthermore, the aperture 23 of the filter card 20 comprises a circular support 28 for mounting thereon a filter membrane 30 and perforated backing members 24. Wherein the support 28 comprises positioning means 29a, 29b for determining the correct position of the filter membrane 30 and backing members 24 when the filter membrane 30 and backing members 24 are mounted on the support 28 of said aperture 23. The positioning means 29a provided on the support 28 interlock with the positioning means 30a provided on the filter membrane 30 and thereby prevent relative rotation of the backing members and the filter membrane and enable the user to correctly mount the filter membrane 30 at the support 28 of the filter card 20. Preferably, said positioning means 29a are at least one convex ridge which fits in at least one suitable recess 30a provided on the periphery of the filter membrane 30. The backing member 24 is preferably provided with indentations 24a, which indentations 24a are evenly distributed over the periphery of the backing member 24. These recesses 24a thus interlock with corresponding raised ridges 29b provided at the periphery of the support 28 of the filter card 20. Wherein the positioning means 29b, 24a for the backing members 24 are designed such that the perforations of the backing members 24 on each side of the filter membrane 30 are aligned. Thus, the user can be effectively guided in the correct way to mount the filter membrane 30 and the perforated backing members 24 on the filter card 20.

In the illustrated embodiment, two filter membranes 30 are mounted on the support 28 of the filter card 20, which are sandwiched between two perforated holders 24. Three or more filter membranes 30 may also be installed to affect the filtering performance of the filter card 20.

A proximity sensor 54 may be provided at the bottom of the hole 42 for inserting the filter card 20. Which enables the presence of the filter card 20 within the hole 42 to be detected. The proximity sensor 54 is preferably connected to at least the pump 2 of the device (see fig. 1). Wherein the sensor 54 preferably transmits a signal in response to the presence of the filter card 20 within the aperture 42. It is ensured that the operation of the pump 2 is only possible when the filter card 20 is fully inserted into the hole 42. Thus, a user may be prevented from inadvertently operating the device without filter card 20 being fully inserted into aperture 42.

Figure 4 shows a preferred embodiment of the enclosing members 40a, 40b enclosing the filter card 20 when the filter card 20 is inserted into the aperture 42 and thereby connected to the water flow path 50. As can be seen from the figures, the filter membrane 30 is sandwiched between two perforated backing members 24. The perforations are aligned so that water passing through the filter card 20 is not deflected.

The water flow path 50 is connected to a circular recess 51 formed in each enclosing member 40a, 40 b. Within this circular recess are provided convex support members 25a, these support members 25a being designed to abut on the support areas 25 of the perforated backing members 24 when the filter card 20 is inserted into said hole 42. Wherein the support areas 25 of the backing members 24 do not comprise any perforations.

As can be seen in fig. 4, both enclosing members 40a, 40b are provided with a circular recess 51b for accommodating the sealing means. The circular recessed portion 51b is preferably concentric with the circular recessed portion 51 that receives the male support member 25 a. A circular recess 51b for accommodating the sealing device 26 is radially provided outside the circular recess 51. The sealing means 26 accommodated by the circular recess 51b thus enables an effective sealing of the aperture 42 when the filter card 20 is arranged in the aperture 42 and when water passes through the filter card 20. The sealing means 26 is preferably an O-ring or the like. Furthermore, the sealing device 26 is preferably replaceable. Therefore, when the sealing device 26 deteriorates, the user can easily replace the sealing device 26. As previously described, sealing means 26 may also be provided on the frame 21 of the filter card 20.

In order to ensure a secure, stable and determined position of the filter card 20 when the filter card 20 is fully inserted into the hole 42, the two enclosing members 40a, 40b may be brought into close contact with the filter card 20 by relatively moving the two enclosing members 40a, 40b, as already described. Alternatively, locking means 51a, 51b may be provided on said frame 21 of the filter card 20. As can be seen from fig. 4, the locking means are, for example, snap-on elements. Thus, it is preferred that the protruding ridge 52a provided on the frame 21 of the filter card 20 interacts with at least one corresponding recess provided on the snap member 52 b. By pressing on this member 52b in the direction of the arrow 53c shown, the user can release the connection between the filter card 20 and the snap-fit member 52b, so that the filter card 20 can be extracted from the aperture 42. The snap member 52b is preferably an integral part of one of the enclosure members 40a, 40 b.

In another preferred embodiment of the filter card 20, the secure, stable position of the filter card 20 within said hole 42 is ensured by the friction (press-fit) between said frame 21 and the abutment surfaces 42a, 42b of the filter card 20. Thus, the fit of the frame 21 within the aperture 42 is selected such that a user must apply a certain force to the filter card 20 in order to fully insert the filter card 20 into the aperture 42. The same applies to the case of removal of the filter card 20 from said hole 42.

Figures 5a and 5b show a preferred embodiment of the backing member 24. Wherein the backing members 24 have individual arcuate recesses 53a and ridges 53b formed so that an exact fit of two identical backing members 24 can be achieved at a predetermined angular position. Thus, the recesses 53a and ridges 53b of the primary backing member 24 interlock with the ridges 53b and recesses 53a provided by the secondary backing member 24. So that relative rotation of the backing members 24 is prevented. Furthermore, since the relative angular positions of the two backing members 24 are defined by the recesses 53a and ridges 53b, the perforations of the two backing members 24 can be effectively aligned. As shown in the figures, support regions 25 are provided on the backing members 24 so as to provide a surface against which support members 25a (see figure 3) of the apparatus can abut.

As can be seen from fig. 5a, the recesses and ridges are preferably arranged symmetrically about the vertical axes a1 and a 2. Further, semicircular depressions 53c and convex semicircular portions 53d are formed on opposite ends of the backing member 24. Thus, when two identical backing members 24 are connected to each other, the semicircular concave portions 53c and convex portions 53d of the two backing members 24 interlock with each other and the correct predetermined assembly position of the two backing members 24 is achieved.

Between the two backing members 24a filter membrane 30 (not shown) is arranged, said filter membrane 30 preferably having a larger diameter than the diameter of the perforated portions of the backing members 24.

As shown in fig. 5b, the dimensions of the concave portion 53a and the convex ridge 53b may vary. For example the height of the recesses 53a and ridges 53b can be adjusted to enable correct mating of the two backing members 24 when assembled. Furthermore, the recesses and ridges may overlap, as indicated by the mark B in fig. 5 a. Thus, a tight, correct fit of the two backing members can be achieved.

During manufacture of the filter card 20, the filter membrane 30 is placed on one of the backing members 24. The second backing member 24 is then placed onto the first backing member 24 with their position relative to each other defined by the arcuate recesses 53a and ridges 53b provided on their engaging faces. In order to make the assembly robust, the frame is injected. Wherein injection ports are preferably provided in the backing members 24 to enable the plastic material to pass during the injection process and thereby further secure the film between the backing members 24. Furthermore, sealing means 26, which may be provided on the outer surface of the backing member 24, may be placed into recesses provided on said backing member 24 prior to the injection process. Correspondingly, the sealing device 26 may also be fixed to the backing member 24 by an injection process.

Fig. 6 shows a cross-sectional view of a preferred embodiment of the filter card 20. As can be seen from the figures, the filter membrane 30 is sandwiched between two perforated backing members 24. The perforations of the backing members 24 are designed such that the diameter of the perforations becomes larger towards the filter membrane 30, i.e. the perforations on the surface adjacent to the filter membrane 30 have a larger diameter than the perforations on the outer side surface of the backing members 24 directed towards the water flow path 50 (see fig. 4).

As can be seen from figure 6, the two backing members 24 interlock due to the circular recesses 53a and ridges 53b provided on the backing members 24. The position of said ridges 53b is chosen such that the filter membrane 30 is as close as possible to the convex inner edges 53c of the convex ridges 53b and/or concave portions 53 a. Thus, the filter membrane 30 can be effectively held in place and a tight enclosure for the filter membrane is achieved.

In addition, a lip seal 26 is provided on the outer surface of the backing member 24 to facilitate sealing of the filter assembly when the filter card 20 is connected to the water flow path 50.

As already described, the sealing means 26 and the backing member 24 may be effectively connected to the frame 21 of the filter card 20 by an injection process during manufacture of the frame 21.

Figure 7 is a cross-sectional side view of another preferred embodiment of filter card 20. In this embodiment, an O-ring 56 is provided in a circular recess 61 provided on one of the backing members 24. Thus, the outer interface between the filter membrane 30 and the backing members 24 is sealed and water cannot pass by the filter membrane 30. Preferably, the recesses 61 and thus the O-rings 56 are provided on the backing members 24 on the upstream side of the filter card 20.

As an alternative to the O-ring 56 shown, a plastic material may be provided to the outer edge of the filter membrane 30 so that it is compressed by the backing members 24 when the filter card 20 is assembled. Such a plastic material can be applied to the filter membrane, for example, by rubber overmolding. Thus, an effective seal against the filter membrane 30 may be provided in order to prevent water passing through the filter card 20 from passing by the filter membrane 30 through the engaging surfaces of the two backing members 24.

Figure 8 shows an exploded assembly view of another preferred embodiment of the filter card. As shown, the backing means 24 is an integral part of the frame 21 of the filter card 20. The backing means 24 is relatively large compared to the other embodiments. The backing means 24 may be a grid formed in the frame 21. Thus, a dedicated support member 25a (see fig. 4) provided on the apparatus may abut on the grid 24 in order to support a stable position of the filter card 20 when the filter card 20 is inserted in said hole 42 (see fig. 4) of the apparatus.

The frame 21 comprises two parts which can be assembled so as to enclose the filter membrane 30 between them. In order to enable correct assembly of the frame 21, positioning means 55a are provided. Preferably, said positioning means 55a are convex and/or concave screws (bolts) arranged in a circle around said grid 24. In this way, the two parts of the frame 21 can be assembled effectively, preventing relative movement of the frame parts 21 after assembly.

As shown in fig. 8, at least one filter membrane 30 is sandwiched between the grids 24 so that water may be effectively supported as it passes through the filter membrane 30. The preferred direction of water flow through the assembly is indicated by arrow 60. Preferably, two or more filter membranes 30 are located between the grids 24. Wherein the filter membranes 30 have different pore sizes. More preferably, the filter membrane located relatively upstream has a larger pore size than the filter membrane located relatively downstream. For example, the upstream filter membrane has a nominal pore size of 0.65 μm and the downstream filter membrane has a nominal pore size of 0.22 μm.

In addition, additional membrane supports 24b may be provided between the grids 24 to further support the filter membrane 30. Preferably, said support member 24b is a circular aluminium grid, wherein the openings of the grid have a smaller size than the backing members 24 of the frame 21. More preferably, the additional support 24b is arranged downstream of the filter membrane 30. Furthermore, a positioning device 55b is preferably provided on the membrane support 24b, which interacts with a positioning device 55a provided on the frame 21 in order to keep the support 24b in a fixed position relative to the frame 21. Preferably, the locating means is a hole formed near the outer edge of the circular support member 24 b.

During assembly, the two frame parts 21 may be manufactured (e.g. injected) as separate components. Thereafter, additional backing members 24b may be secured (e.g., bonded) to one of the backing members 24. Of course, two backing members 24b may be provided on each side of the filter membrane 30.

Fig. 9 shows a preferred embodiment of a closure mechanism 70 of the device, said closure mechanism 70 being arranged to enclose the filter card 20 between two enclosing members 40a, 40 b. The closure mechanism is preferably a lever connected to at least one of the enclosing members 40a, 40b movable relative to each other. Alternatively, a dedicated motor operable by a button may be provided to enable relative movement of the two enclosing members 40a, 40 b.

As can be seen from the figures, the two enclosing members 40a, 40b are arranged such that a dedicated hole 42 for inserting the filter card 20 is formed between them. When the user has fully inserted filter card 20, the user may operate the closure mechanism 70 to facilitate packaging of filter card 20, as shown. Wherein the closing mechanism 70 transfers a mechanical force in order to move the enclosing member 40b towards the other enclosing member 40a, as indicated by arrow 80. Thus, the two enclosing members 40a, 40b are brought into close proximity and the filter card 20 located therebetween is held in place. Thus, the filter card 20 can be fixed in a stable position in the hole 42. Furthermore, when the enclosing members 40a, 40b are brought into close proximity, the sealing means 26 provided on the enclosing members 40a, 40b is pressed against the surface of the filter card 20, thereby enabling a watertight seal of the assembly.

When the user wishes to remove the filter card 20, the closing mechanism is operated in advance to facilitate separation of the two enclosing members 40a, 40 b.

Although the present invention has been described with reference to preferred embodiments thereof, many modifications and changes may be made by one of ordinary skill in the art without departing from the scope of the present invention as defined by the following claims. For example, the filter membrane may be provided in another embodiment of the filter frame structure, so that any operator of the apparatus may replace the filter membrane relatively easily. More than two filter membranes may also be mounted on the filter card in order to enhance the filtering properties of the filter card. In addition, the removable filter card may incorporate other filter media to enable adequate filtration of the water. It is also possible to design a filter card with two or more apertures, each aperture accommodating at least one filter membrane and at least one backing member to facilitate filtering of water through two or more water flow paths of the apparatus to which the filter card is connected. Furthermore, different embodiments of positioning means for the filter membrane and the backing members may be provided on the frame structure of the filter card in order to enable a correct mounting of the filter membrane and the backing members.

Claims (15)

1. An apparatus for preparing a nutritional composition by supplying water to ingredients provided to the apparatus,

the apparatus comprises: a pump (2) connected to an integrated or external water supply (1),

a water discharge end (4) for providing water to a cartridge containing an ingredient (7) for effecting an interaction between the water and the ingredient in the cartridge (7), wherein the pump (2) and the water discharge end (4) are in water communication via a water flow path (50) through which the pump can supply water at a pressure above atmospheric pressure,

a rigid filter assembly (20) and filter packaging (40a, 40 b);

wherein the filter assembly (20) comprises at least one antimicrobial filter membrane (30),

characterized in that the filter assembly (20) and filter packaging means (40a, 40b) are complementarily configured such that the filter assembly (20) can be inserted into the filter packaging means (40a, 40b) in a fluid-tight manner across the water flow path (50) before the drainage end (4) and removed from the filter packaging means (40a, 40b),

the filter assembly (20) comprises a frame (21) for housing a filter comprising the at least one antimicrobial filter membrane (30);

backing means (24) provided adjacent said filter membrane (30) and across the water flow path (50) for supporting a surface of the filter membrane (30) so as to control deflection of the filter membrane (30) and/or avoid rupture thereof as water passes through the filter membrane, said backing means (24) being formed by two perforated backing members;

the antimicrobial filter membrane (30) is sandwiched between the two perforated backing members.

2. Apparatus according to claim 1, wherein the filter assembly (20) has the form of a substantially rigid card, the filter enclosing means (40a, 40b) forming a slot into which the card is insertable.

3. The apparatus of claim 1, wherein the pressure drop across the filter assembly (20) is less than 1 bar.

4. An apparatus according to any one of claims 1-3, wherein the filter assembly (20) and/or filter enclosing means (40a, 40b) further comprises water sealing means (26) for providing a fluid tight seal of the filter assembly (20) in the enclosing means (40a, 40b) when water is passed through the filter assembly (20).

5. An apparatus according to any one of claims 1-3, c h a r a c t e r i z e d in that sealing means (56) are provided between the backing means (24) of the filter assembly (20) and the filter membrane (30) for sealing the lateral engagement surfaces of the backing means (24) and the filter membrane (30).

6. Device according to any one of claims 1 to 3, characterized in that the filter assembly (20) is insertable into a hole (42) provided on one face of the device or removable from the hole (42).

7. The apparatus of claim 6, wherein a sensing device (54) is disposed in the aperture (42) to detect the presence of the filter assembly (20) when the filter assembly (20) is inserted into the apparatus.

8. A device according to any of claims 1-3, wherein the filter assembly (20) further comprises locking means (52a), the locking means (52a) being adapted to interlock with locking means (52b) provided on filter enclosing means (40a, 40b) of the device.

9. Device according to any of claims 1-3, wherein the nutritional composition is an infant formula, prepared from a food composition provided to the device by means of a disposable cartridge (7) insertable into the device.

10. A filter card (20) designed for insertion into an apparatus for preparing a nutritional composition, said filter card (20) comprising a frame (21) for holding in place at least one filter membrane (30) and at least one rigid, water-permeable perforated backing member (24) for supporting the filter membrane (30), characterized in that the filter membrane (30) is an antimicrobial filter membrane having a nominal pore size of between 0.01 and 0.45 microns and a thickness of less than 0.5mm, and that the antimicrobial filter membrane (30) is sandwiched between two perforated backing members (24).

11. The filter card (20) according to claim 10, wherein the frame (21) is made of a rigid plastic and/or metal material for housing the filter membrane (30).

12. The filter card (20) of claim 10, wherein the filter membrane (30) has a thickness of less than 0.2 mm.

13. A filter card (20) according to any of claims 10-12, wherein the backing members (24) have perforations having a larger diameter than the pores of the filter membrane (30).

14. A filter card (20) according to any of claims 10-12, wherein the filter card (20) further comprises a water sealing means (26) for sealing the filter card (20) when the filter card (20) is connected to the device.

15. A filter card (20) according to any of claims 10-12, wherein the filter card (20) comprises asymmetric guiding means (22), the guiding means (22) being configured such that the filter card (20) can only be inserted into the device through a predetermined side.