Patent Description:
For the storage and distribution of unit products, multi-part dispensing devices are known which comprise several components each having a dedicated function. Typically, a dispensing device may comprise a container for storing the unit products, a flow-limiter suitable for dispensing the stored products unit-by-unit, and a closure for reclosably closing the container. One disadvantage of multi-part dispensing devices is that it is difficult to control the tightness of the device due to multiple sealing interfaces. This is particularly a challenge for dispensing devices intended to receive sensitive products, such as food, nutraceutical products, pharmaceutical products or diagnostic products, which require a control of their interior atmosphere, e.g. in terms of humidity level, oxygen level, etc., in order to preserve the sensitive products stored in the device.

It is these drawbacks that the invention is intended more particularly to remedy by proposing a dispensing device making it possible to have a controlled and predictable sealing of the device, so as to ensure a targeted shelf life of unit products stored in the device, while also offering the possibility of a controlled distribution of the unit products.

Further related prior art may be found in <CIT>, <CIT>, and <CIT>, which all relate to a dispensing device with a flow-limiting part and a closure.

The present invention is defined by the independent claim <NUM>. The dependent claims describe optional features and preferred embodiments.

For this purpose, according to a first aspect, a subject of the invention is a dispensing device for storing and dispensing unit products, including a container, a flow-limiting part and a closure, the dispensing device comprising:.

wherein a ratio of a holding force of the first attachment mechanism to a holding force of the second attachment mechanism is higher than or equal to <NUM>, preferably higher than or equal to <NUM>, the holding force of the first attachment mechanism being defined as the opening force required to disassemble the flow-limiting part from the container while the flow-limiting part is assembled with the closure by means of the second attachment mechanism, the holding force of the second attachment mechanism being defined as the opening force required to disassemble the closure from the flow-limiting part while the flow-limiting part is assembled with the container by means of the first attachment mechanism, wherein the holding force of the first attachment mechanism and the holding force of the second attachment mechanism are both determined using an opening force applied parallel to a longitudinal axis (X<NUM>) of the respective tubular portions and with a given opening speed of <NUM>/min.

According to the invention, a holding force of the second attachment mechanism is selected to be higher than or equal to <NUM> N.

According to the invention, a holding force of the second attachment mechanism is further selected to be less than or equal to <NUM> N, preferably less than or equal to <NUM> N.

Hence, a holding force of the second attachment mechanism is selected to be in the range of between <NUM> N and <NUM> N, preferably between <NUM> N and <NUM> N.

Within the frame of the invention, an attachment mechanism is said to be homogeneous over a circumference of the tubular portions of two components of the dispensing device between which it is active, when the holding force of the attachment mechanism is substantially the same regardless of the relative angular orientation of the two components. In other words, such a homogeneous attachment mechanism is evenly distributed over a circumference of the tubular portions of the two components and the opening force required to disassemble the two components from each other, applied parallel to the longitudinal axis of the tubular portions of the two components, is substantially the same regardless of the angular position of the point of application of the opening force on the circumference of said tubular portions. By way of non-limiting examples, such a homogeneous attachment mechanism may include continuous snap-fastening members, e.g. a groove and a complementary projecting ring or bulge, fully surrounding the tubular portions of the two components of the dispensing device, or it may include a plurality of discrete retaining elements regularly distributed over the circumference of the tubular portions of the two components.

Thanks to its specific structure with a controlled difference in holding force between the first attachment mechanism and the second attachment mechanism, the dispensing device according to the invention guarantees a high level of sealing between the three components of the dispensing device. This is particularly important for a dispensing device intended to receive sensitive products and including an active material for the regulation of the atmosphere inside the device. By way of example, the sensitive products may be food, nutraceutical products, pharmaceutical products or diagnostic products, and the active material capable of regulating the atmosphere in the device may be a humidity absorber or an oxygen scavenger. The sealing of such a dispensing device having a controlled atmosphere, represented by its Water Vapor Transmission Rate (WVTR), is key to reach a desired shelf life of the sensitive products stored in the device.

It has been observed that, when the holding force ratio of the first and second attachment mechanisms is selected to be higher than or equal to <NUM> and the holding force of the second attachment mechanism is selected to be in the range of between <NUM> N and <NUM> N, preferably between <NUM> N and <NUM> N, the sealing properties of the three-part dispenser device with two sealing interfaces are substantially equivalent to the sealing properties of a two-part device comprising only a container and a closure with a single sealing interface. Thus, a dispensing device according to the first aspect of the invention, having a holding force ratio higher than or equal to <NUM> and a holding force of the second attachment mechanism in the range of between <NUM> N and <NUM> N, preferably between <NUM> N and <NUM> N, makes it possible to preserve sensitive unit products stored in the device, while offering flow reduction properties for the distribution of the unit products and allowing easy opening of the closure by a user.

A holding force ratio in the range of the invention is also suitable for implementing a method of assembling the dispensing device comprising first a pre-assembly of the flow-limiting part and the closure, and then an assembly of the container with the pre-assembled flow-limiting part and closure. Such an assembly sequence is advantageous in that the pre-assembly of the flow-limiting part and the closure can be carried out by the manufacturer of the components of the dispensing device, while the assembly of the container with the pre-assembled flow-limiting part and closure can be carried out on a packaging line, after a step of filling the container with unit products. Thus, the assembly of the dispensing device can be finalized in a single step on the packaging line, using conventional packaging equipment.

In order to reach a high level of sealing between the three components of the dispensing device, an essential parameter is that a sufficient contact pressure has to be maintained both at the interface between the closure and the flow-limiting part and at the interface between the flow-limiting part and the container. In particular, when the closure is pre-assembled with the flow-limiting part, and the pre-assembled flow-limiting part and closure are stored for a relatively long period of time before being used to seal a container, the pre-assembled flow-limiting part and closure tend to "conform" to each other during the storage period, resulting in a dimensional change including an increase in the outer diameter of the flow-limiting part and a reduction in the diameter of the sealing skirt of the closure. This generates a reduction in the contact pressure at the interface between the closure and the flow-limiting part and, consequently, a degradation of the sealing quality at this interface. It is the same for the interface between the flow-limiting part and the container, which also requires that a sufficient contact pressure be maintained.

It has been found by the inventors that, by setting a holding force ratio of more than <NUM> and a holding force of the second attachment mechanism of between <NUM> N and <NUM> N, preferably between <NUM> N and 40N, the sealing properties of the three-part dispenser device with two sealing interfaces are substantially equivalent to the sealing properties of a two-part device comprising only a container and a closure with a single sealing interface. The selected range for the holding force of the second attachment mechanism makes it possible to achieve the required sealing quality while still preserving the ergonomics of use.

In the context of the invention, the active material for atmosphere regulation may be received in a canister dropped in the container of the dispensing device. As a variant, the active material for atmosphere regulation may be received in a chamber delimited in the closure of the dispensing device. Within the meaning of the invention, an active material is a material capable of regulating the atmosphere in the device. The active material may be any type of active material. In particular, the active material may belong to a group of: humidity absorbers (or desiccants); oxygen scavengers; odor absorbers; and/or emitters of humidity or volatile olfactory organic compounds. Optionally, the active material may be capable of releasing gaseous substances such as moisture or perfume. Such properties can for example be useful for applications where sensitive products require a certain humidity level. Such products are, for example, powders, especially for generating aerosols, gelatin capsules, herbal medicine, gels and creams including cosmetics, and food products.

Examples of suitable dehydrating agents include, without limitation, silica gels, dehydrating clays, activated alumina, calcium oxide, barium oxide, natural or synthetic zeolites, molecular or similar sieves, or deliquescent salts such as magnesium sulfide, calcium chloride, aluminum chloride, lithium chloride, calcium bromide, zinc chloride or the like. Preferably, the dehydrating agent is a molecular sieve and/or a silica gel.

Examples of suitable oxygen collecting agents include, without limitation, metal powders having a reducing capacity, in particular iron, zinc, tin powders, metal oxides still having the ability to oxidize, in particular ferrous oxide, as well as compounds of iron such as carbides, carbonyls, hydroxides, used alone or in the presence of an activator such as hydroxides, carbonates, sulfites, thiosulfates, phosphates, organic acid salts, or hydrogen salts of alkaline metals or alkaline earth metals, activated carbon, activated alumina or activated clays. Other agents for collecting oxygen can also be chosen from specific reactive polymers such as those described for example in the patent documents <CIT>, <CIT>, <CIT> and <CIT>.

According to one embodiment, the flow-limiting part and the closure are made of polymer-based materials, the tensile modulus of the polymer-based material of the closure being strictly lower than the tensile modulus of the polymer-based material of the flow-limiting part. The selection of a polymer-based material for the flow-limiting part that is more rigid than the polymer-based material of the closure makes it possible to limit the expansion of the flow-limiting part under the effect of the stress generated by the closure, and thus maintain a sufficient contact pressure at the interface between the closure and the flow-limiting part.

According to one embodiment, the flow-limiting part and the closure are made of polyolefin-based materials, the polyolefin being the same for the flow-limiting part and the closure and being selected among polyethylene and polypropylene, the tensile modulus of the polyolefin-based material of the closure being strictly lower than the tensile modulus of the polyolefin-based material of the flow-limiting part. The selection of a same polyolefin for the flow-limiting part and the closure, however with different grades so that the material of the flow-limiting part is more rigid than the material of the closure, contributes to an ergonomic opening of the closure, by minimizing the friction that may exist in the case of contact between two strictly identical materials.

According to one embodiment, the container is made of a polymer-based material, the tensile modulus of the polymer-based material of the container being higher than or equal to the tensile modulus of the polymer-based material of the flow-limiting part. The selection of a polymer-based material for the container that is more rigid than the polymer-based material of the flow-limiting part makes it possible to limit the expansion of the container under the effect of the stress generated by the flow-limiting part, and thus maintain a sufficient contact pressure at the interface between the flow-limiting part and the container.

According to one embodiment, the container is made of a polyolefin-based material, the polyolefin being selected among polyethylene and polypropylene, the tensile modulus of the polyolefin-based material of the container being higher than or equal to the tensile modulus of the polyolefin-based material of the flow-limiting part. Here also, the selection of a same polyolefin for the container and the flow-limiting part, however with different grades so that the material of the container is more rigid than the material of the flow-limiting part, minimizes the friction effects.

According to one feature of the invention, the Melt Flow Index (MFI) of the polymer-based material of the closure is higher than the Melt Flow Index (MFI) of the polymer-based material of the flow-limiting part. By way of a non-limiting example, an appropriate selection of constitutive materials for the components of the dispensing device according to the invention may be: polypropylene for the container; and low-density polyethylene (LDPE) for the flow-limiting part and the closure, where the LDPE formulation used for the closure is selected to have a higher Melt Flow Index (MFI) than that of the LDPE formulation used for the flow-limiting part.

According to one feature of the invention, the Water Vapor Transmission Rate (WVTR) of the dispensing device, comprising the container, the flow-limiting part and the closure assembled together, is less than or equal to <NUM> times the WVTR measured for the same container alone sealed in a moisture tight manner.

According to one feature of the invention, the disassembly of the first attachment mechanism involves friction between an internal contact surface of the container and an external contact surface of the flow-limiting part, wherein a deformation for disassembly of the first attachment mechanism is higher than or equal to <NUM>%, the deformation for disassembly of the first attachment mechanism being defined as the ratio of, on the one hand, the absolute value of the difference between a minimum circumference of the contact surface of the container and a maximum circumference of the contact surface of the flow-limiting part to, on the other hand, the maximum circumference of the contact surface of the flow-limiting part, where the circumference values are taken in a configuration where the flow-limiting part is disassembled from the container and assembled with the closure by means of the second attachment mechanism.

According to one feature of the invention, the disassembly of the second attachment mechanism involves friction between an internal contact surface of the flow-limiting part and an external contact surface of the closure, wherein a deformation for disassembly of the second attachment mechanism is less than or equal to <NUM>%, the deformation for disassembly of the second attachment mechanism being defined as the ratio of, on the one hand, the absolute value of the difference between a minimum circumference of the contact surface of the flow-limiting part and a maximum circumference of the contact surface of the closure to, on the other hand, the maximum circumference of the contact surface of the closure, where the circumference values are taken in a configuration where the flow-limiting part is disassembled from the closure and assembled with the container by means of the first attachment mechanism.

According to one embodiment, the first attachment mechanism comprises both an interference press fit between the container and the flow-limiting part, and a snap-fastening connection comprising an inner snap-fastening member of the container and a complementary outer snap-fastening member of the flow-limiting part.

According to one feature, the inner snap-fastening member of the container has a retaining surface which forms a hard point for the disassembly of the snap-fastening members, and this retaining surface is advantageously inclined with respect to the longitudinal axis of the tubular portion of the container at an angle higher than or equal to <NUM>°, preferably higher than or equal to <NUM>°.

According to one embodiment, the second attachment mechanism consists of an interference press fit between the flow-limiting part and the closure, in particular without any snap-fastening connection. In this embodiment, a holding force of the second attachment mechanism of at least 15N may be obtained in the absence of undercut to retain the closure, i.e. with a smooth internal surface of the flow-limiting part, without any retaining member. In particular, in In this embodiment, the sealing may be realized between two planes, i.e. the facing surfaces of the flow-limiting part and the closure, or preferably between a line and a plane, for example in the case of the presence of a bulge on at least one of the facing surfaces of the flow-limiting part and the closure.

According to another embodiment, the second attachment mechanism comprises both an interference press fit between the flow-limiting part and the closure, and a snap-fastening connection comprising an inner snap-fastening member of the flow-limiting part and a complementary outer snap-fastening member of the closure.

According to one feature, the inner snap-fastening member of the flow-limiting part has a retaining surface which forms a hard point for the disassembly of the second snap-fastening members, and this retaining surface is advantageously inclined with respect to the longitudinal axis of the tubular portion of the flow-limiting part at an angle less than or equal to <NUM>°, preferably less than or equal to <NUM>°.

According to one feature, the first attachment mechanism is configured such that the force required to assemble the container with the sub-assembly comprising the flow-limiting part and the closure, pre-assembled by means of the second attachment mechanism, has a predetermined value, below a given threshold value, which allows an automated assembly of said sub-assembly with the container on a packaging line.

According to one feature, the sub-assembly comprising the flow-limiting part and the closure, pre-assembled by means of the second attachment mechanism, is configured to be assembled with the container by means of the first attachment mechanism by a simple displacement of the sub-assembly and the container toward each other along the direction of the aligned longitudinal axes of the tubular portions of the flow-limiting part and the container.

In one embodiment, the closure comprises a chamber for an active material intended to control the atmosphere within the container, and a side wall of the chamber forms a contact surface of the closure which is part of the second attachment mechanism and configured to cooperate by friction with a corresponding contact surface of the flow-limiting part. In this embodiment, the maximum circumference of the contact surface of the closure may be determined by a filling rate of the chamber with the active material. Thus, an adjustment of the holding force of the second attachment mechanism may be obtained through a modulation of the quantity of active material introduced in the chamber of the closure.

In another embodiment, the closure comprises a chamber for an active material intended to control the atmosphere within the container, a side wall of the chamber being surrounded by an outer sealing skirt, with a gap between the side wall and the outer sealing skirt, which outer sealing skirt forms a contact surface of the closure which is part of the second attachment mechanism and configured to cooperate by friction with a corresponding contact surface of the flow-limiting part. In this embodiment, the maximum circumference of the contact surface of the closure is independent from a filling rate of the chamber with the active material, and it may be adjusted according to the design of the outer sealing skirt and the mechanical properties of its constitutive material.

According to one feature, each of the three components of the dispensing device, i.e. the container, the flow-limiting part and the closure, is based on a suitable polymer material. Examples of suitable polymer materials include, without limitation, radical or linear high- and low-density polyethylene, copolymers of ethylene such as for example ethylene vinyl acetates, ethylene ethyl acrylates, ethylene butyl acrylates, ethylene maleic anhydrides, ethylene alpha olefins, regardless of the methods of polymerization or modification by grafting, polypropylene, polybutylene, polyisobutylene. Polyolefins are advantageously selected, for cost reasons and because they are easy to use. However, other polymer materials can also be considered, such as polyvinyl chloride, copolymers of vinyl chloride, polyvinylidene chlorides, polystyrenes, copolymers of styrene, derivatives of cellulose, polyamides, polycarbonates, polyoxymethylenes, polyethylene terephthalates, polybutylene terephthalates, copolyesters, polyphenylene oxides, polymethyl methacrylates, copolymers of acrylate, fluoride polymers, polyimides, polyurethanes, etc..

Combinations of these polymers can be used, if desired. The polymers used to produce the three components of the dispensing device, i.e. the container, the flow-limiting part and the closure, can also contain one or more additives such as fibers, expanding agents, additives such as stabilizers and colorants, sliding agents, demolding agents, adhesion agents or reinforced catching agents and/or any others according to the requirements of usage.

According to one embodiment, in the assembled configuration of the dispensing device, the first and second attachment mechanisms are positioned within the container and, in the direction of the longitudinal axis of the tubular portion of the container, the first attachment mechanism is further away from the open end of the container than the second attachment mechanism. Since the rigidity of the container increases away from its open end, such an arrangement contributes to a higher holding force of the first attachment mechanism compared to that of the second attachment mechanism.

According to a second aspect, a subject of the invention is a dispensing device for storing and dispensing unit products, including a container, a flow-limiting part and a closure, the dispensing device comprising:.

Thanks to such a controlled difference between the deformation for disassembly of the first attachment mechanism and the deformation for disassembly of the second attachment mechanism, the dispensing device according to the second aspect of the invention guarantees a high level of sealing between the three components of the dispensing device. In particular, the sealing properties of the three-part dispenser device with two sealing interfaces may be substantially equivalent to the sealing properties of a two-part device comprising only a container and a closure with a single sealing interface. In this way, a dispensing device according to the second aspect of the invention makes it possible to preserve sensitive unit products stored in the device, while offering flow reduction properties for the distribution of the unit products and allowing easy opening of the closure by a user.

Another subject of the invention is a method for assembling and filling a dispensing device as described above, comprising steps in which:.

When the closure of the dispensing device comprises a chamber for an active material, a side wall of which forms a contact surface which is part of the second attachment mechanism as described above, the method advantageously comprises steps in which:.

Features and advantages of the invention will become apparent from the following description of several embodiments of a dispensing device and a method according to the invention, this description being given merely by way of example and with reference to the appended drawings in which:.

In the first embodiment shown in <FIG>, the dispensing device <NUM> is intended for the storage and the dispensing of sensitive unit products, such as diagnostic test strips, or nutraceutical or pharmaceutical products e.g. in the form of pills, lozenges or tablets. The dispensing device <NUM> comprises three components, including a container <NUM> for storing the unit products, a flow-limiting part <NUM> for dispensing the unit products in a controlled manner, preferably unit-by-unit, and a closure <NUM> for re-closably closing the container <NUM>. In the example shown in the figures, the dispensing device <NUM> has a cylindrical shape centered on a longitudinal axis X<NUM>, it being understood that other shapes are also possible in the context of the invention.

The container <NUM> comprises a bottom wall <NUM>, a peripheral wall <NUM> and an open end <NUM> on the opposite side from the bottom wall <NUM>. The open end <NUM> is intended to be closed by the closure <NUM>, after insertion of the flow-limiting part <NUM>. The flow-limiting part <NUM> is configured to prevent the inadvertent discharge of more than one product at a time. To this end, the flow-limiting part <NUM> comprises an annular wall <NUM> with a peripheral rim <NUM> at one end, from which extends a substantially convex guide portion <NUM>. The convex guide portion <NUM> comprises three curved legs which connect the peripheral rim <NUM> to a central orifice <NUM> while delimiting between them three dispensing apertures <NUM>. The convex guide portion <NUM> ensures the return of a possible excess products that may have been dispensed back in the container <NUM> through the dispensing apertures <NUM>.

The closure <NUM> comprises a top wall <NUM> and a side wall <NUM> extending therefrom. The top wall defines a peripheral gripping portion <NUM>, which may comprise ridges or other protruding features configured to facilitate gripping. As clearly visible in <FIG>, the closure <NUM> comprises a chamber <NUM> for receiving an active material <NUM> capable of regulating the atmosphere in the container <NUM>, in particular a desiccant and/or an oxygen scavenger. The chamber <NUM>, delimited between the top wall <NUM> and the side wall <NUM>, is closed by a gas-permeable cover <NUM> which retains the active material <NUM> inside the chamber. In the represented example, the gas-permeable cover <NUM> is a cardboard held at its periphery by thinner extensions of the side wall <NUM> which have been crimped. In other embodiments, the gas-permeable cover <NUM> may be a porous membrane secured to the distal end of the side wall <NUM>, e.g. by heat-sealing, ultrasonic welding, overmolding, etc..

In this first embodiment, by way of a non-limiting example: all of the container <NUM>, the flow-limiting part <NUM> and the closure <NUM> are obtained by injection molding of polymer materials; the constitutive polymer material of the container <NUM> is a polypropylene having a tensile module of <NUM> MPa (ISO527) and a flexural modulus of <NUM> MPa (ASTM D790); the constitutive polymer material of the flow-limiting part <NUM> is a low-density polyethylene (LDPE) having a tensile modulus of <NUM> MPa (ISO527) and a Melt Flow Index (MFI) of <NUM>/<NUM> (ISO1133-<NUM>, <NUM> / <NUM>); the constitutive polymer material of the closure <NUM> is a low-density polyethylene (LDPE) having a tensile module of <NUM> MPa (ISO527), a flexural modulus of <NUM> MPa (ASTM D790) and a Melt Flow Index (MFI) of <NUM>/<NUM> (ISO1133-<NUM>, <NUM> / <NUM>). According to an advantageous feature, the constitutive polymer material of the flow-limiting part <NUM> is a low-density polyethylene (LDPE) containing an antiblocking agent.

The dispensing device <NUM> comprises a first attachment mechanism between the container <NUM> and the flow-limiting part <NUM>, and a second attachment mechanism between the flow-limiting part <NUM> and the closure <NUM>. The first attachment mechanism comprises an interference press fit between the peripheral wall <NUM> of the container <NUM> and the annular wall <NUM> of the flow-limiting part <NUM>, combined with a snap-fastening connection between an inner peripheral groove <NUM> of the peripheral wall <NUM> of the container and an outer peripheral ring <NUM> of the annular wall <NUM> of the flow-limiting part. The second attachment mechanism only comprises an interference press fit between the annular wall <NUM> of the flow-limiting part <NUM> and an outer peripheral bulge <NUM> of the side wall <NUM> of the closure <NUM>.

The disassembly of both the first and second attachment mechanisms involves friction between contact surfaces. More precisely, the disassembly of the first attachment mechanism involves friction between an internal contact surface <NUM> formed by an upper portion of the peripheral wall <NUM> of the container including the inner groove <NUM>, and an external contact surface <NUM> formed by the outer peripheral ring <NUM> of the flow-limiting part. The inner groove <NUM> of the container has a retaining surface S<NUM>, which forms a geometrical hard point for the disassembly of the outer ring <NUM> out of the inner groove <NUM>. Advantageously, in this example, the retaining surface S<NUM> is inclined, with respect to the direction of the longitudinal axis X<NUM>, at an angle α of the order of <NUM>°, i.e. higher than <NUM>°. Such a relatively high inclination angle α of the retaining surface S<NUM> ensures a strong resistance to disassembly of the first attachment mechanism.

The disassembly of the second attachment mechanism involves friction between an internal contact surface <NUM> formed by the flat annular wall <NUM> of the flow-limiting part and an external contact surface <NUM> formed by the outer bulge <NUM> of the side wall <NUM> of the closure. Interestingly, in this first embodiment, since the contact surface <NUM> of the closure is defined by the side wall <NUM> delimiting the chamber <NUM>, the maximum circumference of the contact surface <NUM> of the closure may be determined by a filling rate of the chamber <NUM> with the active material. Thus, an adjustment of the holding force of the second attachment mechanism may be obtained through a modulation of the quantity of active material introduced in the chamber <NUM>. In this first embodiment, since the annular wall <NUM> of the flow-limiting part is flat, there is no geometrical hard point on the way for the disassembly of the outer bulge <NUM> relative to the flat wall <NUM>. As the flat annular wall <NUM> is substantially parallel to the longitudinal axis X<NUM> of the dispensing device, in this example, the inclination angle β of the retaining surface formed by the flat annular wall <NUM>, with respect to the direction of the longitudinal axis X<NUM>, is substantially zero. It is understood that the flow-limiting part <NUM> has a draft angle of between <NUM>° and <NUM>°, but the inclined surface resulting from this draft angle is not a retention surface since the annular wall <NUM> flares toward the free end of the flow-limiting part <NUM> opposite from the convex guide portion <NUM>.

In this first embodiment, the deformation required for the disassembly of the first attachment mechanism is selected to be higher than or equal to <NUM>%, thanks to the selection of appropriate values for the inner diameter of the upper portion of the peripheral wall <NUM> of the container <NUM> located between the inner groove <NUM> and the open end <NUM> of the container, the diameter at the bottom of the inner groove <NUM> of the container, and the outer diameter at the apex of the outer ring <NUM> of the flow-limiting part <NUM>. The inner diameter of the upper portion of the peripheral wall <NUM> of the container <NUM> defines the minimum circumference L<NUM> of the contact surface <NUM> of the container, whereas the outer diameter at the apex of the outer ring <NUM> of the flow-limiting part <NUM> defines the maximum circumference L<NUM> of the contact surface <NUM> of the flow-limiting part. It is noted that the values of the minimum circumference L<NUM> and the maximum circumference L<NUM> are taken in a configuration where the flow-limiting part <NUM> is disassembled from the container <NUM> and assembled with the closure <NUM> by means of the second attachment mechanism, which corresponds to the configuration shown in <FIG>. By way of example, in this illustrative embodiment, the minimum circumference L<NUM> is <NUM>; the maximum circumference L<NUM> is <NUM>; the deformation required for disassembly of the first attachment mechanism is <NUM>%.

In the same way, the deformation required for the disassembly of the second attachment mechanism is selected to be less than or equal to <NUM>%, thanks to the selection of appropriate diameters for the upper portion of the flat annular wall <NUM> of the flow-limiting part <NUM> and the outer bulge <NUM> of the closure <NUM> which define, respectively, the minimum circumference L<NUM> of the contact surface <NUM> of the flow-limiting part and the maximum circumference L<NUM> of the contact surface <NUM> of the closure. Here, it is noted that the values of the minimum circumference L<NUM> and the maximum circumference L<NUM> are taken in a configuration where the flow-limiting part <NUM> is disassembled from the closure <NUM> and assembled with the container <NUM> by means of the first attachment mechanism, which corresponds to the configuration shown in <FIG>. By way of example, in this illustrative embodiment, the minimum circumference L<NUM> is <NUM>; the maximum circumference L<NUM> is <NUM>; the deformation required for disassembly of the second attachment mechanism is <NUM>%.

The respective holding forces of the first attachment mechanism and the second attachment mechanism of the dispensing device <NUM> according to the first embodiment have been determined using an automated force tester (Chatillon TCD200).

Several sub-assemblies comprising the container <NUM> assembled with the flow-limiting part <NUM> were fixed on the force tester. The flow-limiting part <NUM> was submitted to a vertical force exerted by a hook that displaces upwardly, i.e. parallel to the longitudinal axis X<NUM> of the dispensing device. The vertical force was applied to the lower surface of the peripheral rim <NUM> of the flow-limiting part <NUM>, with a traction speed of <NUM>/min. The vertical force was recorded until the flow-limiting part <NUM> was removed from the container <NUM>.

Closed dispensing devices <NUM>, comprising all of the container <NUM>, the flow-limiting part <NUM> and the closure <NUM> assembled together, were fixed on the force tester. The closure <NUM> was submitted to a vertical force exerted by a hook that displaces upwardly, i.e. parallel to the longitudinal axis X<NUM> of the dispensing device. The vertical force was applied to a point of the gripping portion <NUM> of the closure with a traction speed of <NUM>/min. The vertical force was recorded until the closure <NUM> was removed from the flow-limiting part <NUM>.

The corresponding opening forces (N) were recorded in the table below, and the corresponding holding force ratio was computed:.

It is noted that the above measurements of the opening force for the first attachment mechanism have been obtained in a configuration where the flow-limiting part <NUM> was not assembled with the closure <NUM> by means of the second attachment mechanism. In practice, the presence of the closure <NUM> attached to the flow-limiting part <NUM> by means of the second attachment mechanism increases the holding force of the first attachment mechanism. This is because the sealing pressure applied by the external contact surface <NUM>, formed by the outer bulge <NUM> of the closure, onto the internal contact surface <NUM> formed by the flat annular wall <NUM> of the flow-limiting part, tends to increase the outer diameter at the apex of the outer ring <NUM> of the flow-limiting part <NUM>, which defines the maximum circumference L<NUM>s of the contact surface <NUM> of the flow-limiting part.

As a result, the deformation and the opening force required to deactivate the first attachment mechanism, i.e. to disassemble the flow-limiting part <NUM> from the container <NUM>, increases when the closure <NUM> is assembled with the flow-limiting part <NUM> by means of the second attachment mechanism, compared to when the closure <NUM> is not assembled with the flow-limiting part <NUM>. Hence, in the table above, the data of the opening force for the first attachment mechanism and of the holding force ratio are underestimated compared to a case where the opening force for the first attachment mechanism is measured in a configuration where the flow-limiting part <NUM> is assembled with the closure <NUM> by means of the second attachment mechanism.

The air-tightness of several closed dispensing devices <NUM> of the first embodiment, comprising the container <NUM>, the flow-limiting part <NUM> and the closure <NUM> assembled together, has also been determined, through measurements of the Water Vapor Transmission Rate (WVTR) according to ASTM-D7709. To evaluate the leak rate induced by the double sealing interface at the first and second attachment mechanisms, the WVTR values of the dispensing devices <NUM> have been compared to reference values obtained for the same containers <NUM> sealed in a moisture tight manner. In this example, WVTR reference values were obtained by sealing an aluminum foil seal to the open end <NUM> of the containers. Alternatively, WVTR reference values for the containers alone may be obtained by gluing a metal plate to the open end <NUM> of the containers with epoxy or hot-melt adhesive, or by using a moisture tight reference closure, which may also optionally be tightened to the container with a sealing resin.

The WVTR measurements were recorded in the table below. In each case, the measured values were obtained for a container <NUM> molded from polypropylene; a flow limiting part <NUM> and a closure <NUM> molded from low-density polyethylene (LDPE). The container had a wall thickness of <NUM>, a circular cross section with external diameter of <NUM> and an overall height of <NUM>.

The absolute value of the WVTR varies according to dimensional parameters (exchange surface resulting from height and diameter, wall thickness) and material selection. However, it has been observed that, when the holding force ratio of the first and second attachment mechanisms is selected in the range of the invention, the sealing properties of the three-part dispenser device with two sealing interfaces are substantially equivalent to the sealing properties obtainable for a two-part device comprising only a container and a closure with a single sealing interface. As shown above, the WVTR of the dispensing device <NUM>, comprising all of the container <NUM>, the flow-limiting part <NUM> and the closure <NUM> assembled together, is less than or equal to <NUM> times a reference WVTR measured for the container alone sealed in a moisture tight manner.

Thus, the dispensing device <NUM> of the first embodiment, having a holding force ratio in the range of the invention, makes it possible to preserve sensitive unit products stored in the device, while offering flow reduction properties for the distribution of the unit products and allowing an easy opening of the closure by a user, in particular with an opening force of the closure of less than <NUM> N.

In the second embodiment shown in <FIG>, elements that are similar to those of the first embodiment have the same references. The dispensing device <NUM> of the second embodiment differs from the first embodiment in that the sealing portion of the closure <NUM> is formed by an outer sealing skirt <NUM> of the closure, instead of the side wall <NUM> of the chamber <NUM>. In this second embodiment, the side wall <NUM> of the chamber <NUM> is surrounded by the outer sealing skirt <NUM>, with a gap between the side wall <NUM> and the outer sealing skirt <NUM>. The outer sealing skirt <NUM> forms a contact surface <NUM> of the closure which is part of the second attachment mechanism and configured to cooperate by friction with the contact surface <NUM> of the flow-limiting part.

As in the first embodiment, the first attachment mechanism comprises an interference press fit between the peripheral wall <NUM> of the container <NUM> and the annular wall <NUM> of the flow-limiting part <NUM>, combined with a snap-fastening connection between an inner peripheral groove <NUM> of the peripheral wall <NUM> of the container and an outer peripheral ring <NUM> of the annular wall <NUM> of the flow-limiting part. The disassembly of the first attachment mechanism involves friction between an internal contact surface <NUM> formed by an upper portion of the peripheral wall <NUM> of the container including the inner groove <NUM>, and an external contact surface <NUM> formed by the outer peripheral ring <NUM> of the flow-limiting part. The inner groove <NUM> of the container has a retaining surface S<NUM> inclined, with respect to the direction of the longitudinal axis X<NUM>, at an angle α of the order of <NUM>°, i.e. higher than <NUM>°.

In this second embodiment, the second attachment mechanism comprises an interference press fit between the annular wall <NUM> of the flow-limiting part <NUM> and the outer skirt <NUM> of the closure <NUM>, combined with a snap-fastening connection between an inner peripheral groove <NUM> of the annular wall <NUM> of the flow-limiting part and an outer peripheral bulge <NUM> of the outer skirt <NUM> of the closure. The disassembly of the second attachment mechanism involves friction between an internal contact surface <NUM> formed by the annular wall <NUM> of the flow-limiting part including the inner groove <NUM>, and an external contact surface <NUM> formed by the outer bulge <NUM> of the outer skirt <NUM> of the closure. The inner groove <NUM> of the flow-limiting part has a retaining surface S<NUM> inclined, with respect to the direction of the longitudinal axis X<NUM>, at an angle β of the order of <NUM>°, i.e. less than <NUM>°.

Here again, the deformation required for the disassembly of the first attachment mechanism is selected to be higher than or equal to <NUM>%, thanks to the selection of appropriate values for the inner diameter of the peripheral wall <NUM> of the container <NUM>, the diameter at the bottom of the inner groove <NUM> of the container <NUM> and the outer diameter at the apex of the outer ring <NUM> of the flow-limiting part <NUM>, where the inner diameter of the peripheral wall <NUM> of the container <NUM> defines the minimum circumference L<NUM> of the contact surface <NUM> of the container, whereas the outer diameter at the apex of the outer ring <NUM> of the flow-limiting part <NUM> defines the maximum circumference L<NUM> of the contact surface <NUM> of the flow-limiting part. The values of the minimum circumference L<NUM> and the maximum circumference L<NUM> are taken in a configuration where the flow-limiting part <NUM> is disassembled from the container <NUM> and assembled with the closure <NUM> by means of the second attachment mechanism, which corresponds to the configuration shown in <FIG>. By way of example, in this illustrative second embodiment, the minimum circumference L<NUM> is <NUM>; the maximum circumference L<NUM> is <NUM>; the deformation required for disassembly of the first attachment mechanism is <NUM>%.

In the same way, the deformation required for the disassembly of the second attachment mechanism is selected to be less than or equal to <NUM>%, thanks to the selection of appropriate diameters for the inner diameter of the annular wall <NUM> of the flow-limiting part <NUM>, the diameter at the bottom of the inner groove <NUM> of the flow-limiting part <NUM> and the outer diameter at the apex of the outer bulge <NUM> of the closure, where the inner diameter of the annular wall <NUM> of the flow-limiting part <NUM> defines the minimum circumference L<NUM> of the contact surface <NUM> of the flow-limiting part, whereas the apex of the outer diameter of the outer bulge <NUM> of the closure <NUM> defines the maximum circumference L<NUM> of the contact surface <NUM> of the closure. The values of the minimum circumference L<NUM> and the maximum circumference L<NUM> are taken in a configuration where the flow-limiting part <NUM> is disassembled from the closure <NUM> and assembled with the container <NUM> by means of the first attachment mechanism, which corresponds to the configuration shown in <FIG>. By way of example, in this illustrative embodiment, the minimum circumference L<NUM> is <NUM>; the maximum circumference L<NUM> is <NUM>; the deformation required for disassembly of the second attachment mechanism is <NUM>%.

The respective holding forces of the first attachment mechanism and the second attachment mechanism of the dispensing device <NUM> according to the second embodiment have been determined as in the first embodiment, using an automated force tester (Chatillon TCD200), yielding an average holding force ratio higher than <NUM>.

In the third embodiment shown in <FIG>, elements that are similar to those of the first and second embodiments have the same references. The dispensing device <NUM> of the third embodiment differs from the second embodiment only in that the snap-fastening connection is between the outer peripheral bulge <NUM> of the outer skirt <NUM> of the closure and an inner peripheral bead <NUM>' of the annular wall <NUM> of the flow-limiting part, instead of the inner peripheral groove <NUM>. The disassembly of the second attachment mechanism involves friction between the internal contact surface <NUM> formed by the annular wall <NUM> of the flow-limiting part including the inner bead <NUM>', and the external contact surface <NUM> formed by the outer bulge <NUM> of the outer skirt <NUM> of the closure. The inner bead <NUM>' of the flow-limiting part has a retaining surface S<NUM>' inclined, with respect to the direction of the longitudinal axis X<NUM>, at an angle β of the order of <NUM>°, i.e. less than <NUM>°.

As can be seen from the above description of several embodiments of a dispensing device according to the invention,.

Claim 1:
Dispensing device (<NUM>) for storing and dispensing unit products, including a container (<NUM>), a flow-limiting part (<NUM>) and a closure (<NUM>), the dispensing device comprising:
- a first attachment mechanism between a tubular portion (<NUM>) of the container (<NUM>) and a tubular portion (<NUM>) of the flow-limiting part (<NUM>), the first attachment mechanism being homogeneous over a circumference of the tubular portions of the container and the flow-limiting part, and
- a second attachment mechanism between a tubular portion (<NUM>) of the flow-limiting part (<NUM>) and a tubular portion (<NUM>; <NUM>) of the closure (<NUM>), the second attachment mechanism being homogeneous over a circumference of the tubular portions of the flow-limiting part and the closure,
wherein a ratio of a holding force of the first attachment mechanism to a holding force of the second attachment mechanism is higher than or equal to <NUM>, preferably higher than or equal to <NUM>, the holding force of the first attachment mechanism being defined as the opening force required to disassemble the flow-limiting part from the container while the flow-limiting part is assembled with the closure by means of the second attachment mechanism, the holding force of the second attachment mechanism being defined as the opening force required to disassemble the closure from the flow-limiting part while the flow-limiting part is assembled with the container by means of the first attachment mechanism, wherein the holding force of the first attachment mechanism and the holding force of the second attachment mechanism are both determined using an opening force applied parallel to a longitudinal axis (X<NUM>) of the respective tubular portions and with a given opening speed of <NUM>/min, and
wherein a holding force of the second attachment mechanism is higher than or equal to <NUM> N and less than or equal to <NUM> N, preferably less than or equal to <NUM> N.