METHOD AND DEVICE FOR APPLYING A SEALING MEMBER ONTO A BEVERAGE CAPSULE

Abstract

The invention relates to a method for applying a sealing member onto the cup-shaped container of a capsule intended for producing a beverage in a beverage production device, wherein the container has a bottom wall, a side wall with an outer surface, an open end and an annular flange which extends from the side wall of the container at the open end; the flange comprising a flange outer surface merging with the outer surface of the side wall at a transition area an flange inner surface opposite to the outer surface for being sealed with a beverage delivery wall, the method comprising the steps of: depositing molten thermoplastic polymer material by a depositing apparatus onto the outer surface of the annular flange and/or onto the transition area, subsequently pressing the thermoplastic polymer material by a punch-die while the material still being plastically deformable so as to conform it in its final shape onto the outer surface of the annular flange and/or onto the transition area thereby forming it into an annular sealing member attached to the container. The invention further relates to a device adapted for carrying out the method.

Claims

1. Method for applying a sealing member onto the cup-shaped container of a capsule intended for producing a beverage in a beverage production device, wherein the container has a bottom wall, a side wall with an outer surface, an open end and an annular flange which extends from the side wall of the container at the open end; the flange comprising a flange outer surface merging with the outer surface of the side wall at a transition area and a flange inner surface opposite to the outer surface for being sealed with a beverage delivery wall, the method comprising the steps of: depositing molten thermoplastic polymer material by a depositing apparatus onto the outer surface of the annular flange and/or onto the transition area; and subsequently pressing the thermoplastic polymer material by a punch-die while the material still being plastically deformable so as to conform it onto the outer surface of the annular flange and/or onto the transition area thereby forming it into an annular sealing member attached to the container.

2. Method according to claim 1, wherein the pressing step comprises forming the thermoplastic polymer material into its final shape by pressing a circumferential punch-die comprising a continuous annular pressing surface against the mass of thermoplastic material.

3. Method according to claim 2, wherein the depositing step comprises depositing the molten thermoplastic material into a single circumferential portion of the polymer material.

4. Method according to claim 2, wherein the depositing step comprises depositing the molten thermoplastic polymer material into a circumferential arrangement of two or a plurality of separate portions.

5. Method according to claim 1, wherein the depositing step comprises depositing the molten thermoplastic polymer material by a depositing apparatus selected from the group consisting of: a circumferential dispensing nozzle sized to the circumference of the flange; a moving nozzle displaced along the circumference of the flange; and a plurality of nozzles disposed along the circumference of the flange.

6. Method according to claim 1, wherein the depositing step comprises depositing the molten thermoplastic material by a depositing apparatus comprising a circumferential dispensing nozzle and a central recess arranged for accommodating at least partially the cup-shaped body of the capsule.

7. Method according to claim 1, wherein the deposited amount of molten thermoplastic material is controlled at least partially by the opening time of an outlet nozzle or by the pressure time applied to a one-way dosing valve of the nozzle.

8. Method according to claim 1, wherein the thermoplastic material is a thermoplastic elastomer (“TPE”) selected from the group consisting of: Styrenes; Copolyesters; Copolyamides; Polyurethanes; Polyamides; Polyolefin Blends; Polyolefin Alloys; Reactor TPO's; Polyolefin Plastomers; Polyolefin Elastomers; and combinations thereof or soft thermoplastic polymer.

9. Device for applying a sealing member onto the cup-shaped container of a capsule intended for producing a beverage in a beverage production device, wherein the container has a bottom wall, a side wall with an outer surface, an open end and an annular flange which extends from the side wall of the container at the open end; the flange comprising a flange outer surface merging with the outer surface of the side wall at an transition area and a flange inner surface opposite to the outer surface for being sealed with a beverage delivery wall; the device comprising: a depositing apparatus for depositing molten thermoplastic polymer material onto the outer surface of the annular flange and/or onto the transition area; and a pressing apparatus for pressing the molten thermoplastic polymer material so as to conform it onto the outer surface of the annular flange and/or onto the transition area thereby forming it into an annular sealing member attached to the container.

10. Device according to claim 9, wherein the pressing apparatus comprises a circumferential punch-die comprising a continuous annular pressing surface for pressing against the mass of thermoplastic polymer material.

11. Device according to claim 10, wherein the pressing apparatus is cooled down by cooling member.

12. Device according to claim 9, wherein the depositing apparatus comprises a circumferential dispensing nozzle and a central recess for accommodating at least partially the container of the capsule.

13. Device according to claim 12, wherein the circumferential dispensing nozzle is arranged with an annular dosing outlet or a plurality of annular or cylindrical outlet circumferentially arranged along a circle having a diameter substantially equal or slightly larger than the diameter of the transition area of the container of the capsule.

14. Device according to claim 12, wherein the depositing apparatus comprises an inner part, an outer part and a dispensing passage in-between.sub..,. the two parts being coaxial and the inner part and outer part being arranged for axially moving relative to one another between a closed position and an open depositing position.

15. Device according to claim 12, wherein the depositing apparatus comprises heating means in the inner part and/or outer part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG. 1 is flow chart of a possible method of the invention;

[0050] FIG. 2 is a schematic representation in perspective of a depositing apparatus;

[0051] FIG. 3 is a schematic cross-sectional representation of a depositing apparatus and depositing step before depositing;

[0052] FIG. 4 is a schematic cross-sectional representation of a depositing apparatus and depositing step during depositing;

[0053] FIG. 5 is an enlarged view of the depositing apparatus with the nozzle opened when depositing molten thermoplastic material on the container of the capsule;

[0054] FIG. 6 is a top view of a container of capsule with a continuous depositing of molten thermoplastic material before forming of the sealing member;

[0055] FIG. 7 is a top view of a container of capsule with a discontinuous depositing of molten thermoplastic material before forming of the sealing member;

[0056] FIG. 8 is a top view of a container of capsule with the sealing member after forming;

[0057] FIG. 9 is a schematic cross-sectional view of the punch-die apparatus;

[0058] FIGS. 10 and 11 are schematic representations of the forming step with a convex punch-die;

[0059] FIGS. 12 and 13 are schematic representations of the forming step with a flat punch-die;

[0060] FIGS. 14 and 15 are schematic representations of the forming step with a concave punch-die;

[0061] FIGS. 16 and 17 are schematic representations of the forming step with a slanted punch-die;

[0062] FIGS. 18 and 19 are schematic representations of the forming step with a corrugated punch-die;

[0063] FIG. 20 is a schematic representation of the formed sealing after forming with a structuring, e.g. spiky, punch-die.

DESCRIPTION OF PARTICULAR ASPECTS AND EMBODIMENTS OF THE INVENTION

[0064] To start with, an example of the method and apparatus of the invention can be described in relation to FIGS. 1 to 9.

[0065] The application method of the invention comprises applying a sealing member 2 onto a cup-shaped container 1 of a beverage capsule. As shown by FIG. 1, the method generally comprises a step 100 of melting thermoplastic material 3, a step 200 of depositing the molten material on the cup-shaped container 1, a step 300 of plastically deforming the deposited thermoplastic material and optionally a step 400 of cooling the formed thermoplastic material to produce a hardened sealing member. A subsequent forming after cooling is not preferred but not fully excluded either.

[0066] Generally (FIG. 3), the cup-shaped container 1 has a bottom wall 6, a side wall 7 with an outer surface 8, an open end 9 and an annular flange 10 which extends from the side wall of the container at the open end. The annular flange 10 comprises a flange outer surface 11 merging with the outer surface 8 of the side wall at a transition area 12. The flange further comprises a flange inner surface 13 opposite to the outer surface 11 for being sealed (after filling of the container with beverage ingredients) with a beverage delivery wall.

[0067] In the mode of FIGS. 2 and 3, the depositing apparatus 4 is illustrated with a circumferential depositing nozzle 5 which can open to dispense the molten material and close to stop dispensing it, but other variations are possible such as a moving nozzle which is displaced when depositing along the circumference of the annular flange or a plurality of independent depositing nozzles distributed at the circumference of the flange 10 of the capsule.

[0068] The depositing apparatus 4 comprises a support subassembly 14 configured for receiving the container of the capsule in a defined position especially with a form that fits in the cavity of the container through the open end. The apparatus may comprise a depositing subassembly 15 comprising a depositing nozzle 5. The depositing subassembly can comprise an inner part 16 and an outer part 17 which are coaxial and define together a molten material flow passage 18 communicating with the circumferential nozzle 5. The two parts are axially moveable relative to each other (along axis I also representing the container longitudinal axis) to ensure opening of the nozzle for depositing and closing it for stopping the deposition.

[0069] In this example, the inner part is axially reciprocating between the open and closed position of the depositing nozzle. The outer part remains stationary. The inner part can be mounted with a central axle 20 axially moving in a bore 21 of the outer part.

[0070] The inner part preferably comprise a central recess 19 which is arranged for accommodating the container of the capsule such that the depositing nozzle can come as close as possible to the depositing area of the container. The position of the nozzle relative to the flange and the geometry of the recess may be adapted as a function of the desired final position and/or shape of the sealing member.

[0071] The molten thermoplastic material can be kept in the depositing apparatus in molten state by heating means. The heating means may be located in the outer part and/or inner part. In the example, the heating means can be at least one electrical resistance and/or at least one heated fluid conduit 23 embedded in the outer part.

[0072] The molten material can be kept pressurized in the depositing apparatus such as by means of a mechanical and/or hydraulic pressure device. The pressure device can also be external to the apparatus such as arranged in a remote melting reservoir of molten material. It can be, for instance, a piston or screw device arranged to supply molten material to the flow passage 18 such as via conduits 25, 26. Melting of the material can also be initiated remotely and supplied to the depositing apparatus through the flow passage 18. Polymer material may be fed in a melting reservoir or apparatus in the form of powder or pellets.

[0073] FIGS. 4 and 5 illustrate the depositing operation. As the inner part 16 is retracted, a circumferential depositing outlet 24 is opened allowing the molten material to flow off the nozzle and deposit on the outer surface 11 of the flange. For example, an annular cord 27 of molten material is produced and deposited on the surface until the nozzle closes off by the inner part returning to the initial position in sealed contact with the outer part.

[0074] The flow of material is controlled by the opening of the outlet (size and opening time). Such control enables to deposit an amount of molten material as small as a few tens of milligrams. Typically, the opening time is a matter of milliseconds and the width of the outlet is a matter of few tenths of a millimeter.

[0075] The depositing area on the container can be varied by varying the diameter of the inner part 16 or recess 19 and the depositing of material can take place at the transition area 12 of the flange and side wall of the capsule's container for instance.

[0076] FIG. 6 shows a continuous deposited mass 27 of thermoplastic material after depositing and before forming. The mass is deposited with a depositing nozzle forming an annular outlet 24 which is, in opened position, continuously open and delimited by the inner and outer parts along the full circumference of the nozzle.

[0077] FIG. 7 shows the mass formed by a circumferential arrangement of a plurality of deposited portions 27a-i of sealing polymer material before forming. The portions can be arc-shaped or a plurality of tiny dots of polymer spaced by a short distance. The portions are deposited with a depositing nozzle forming a plurality of annular outlets which are delimited by the inner and outer parts. For instance, outlet separations can be obtained by a particular structure in relief and/or recess of the nozzle formed by the inner and/or outer parts 16, 17.

[0078] FIG. 8 shows the sealing member 2 applied on the container of the capsule after forming. The forming may spread the portions 27a-i to such an extent that the neighbouring portions meet or overlap in the circumferential direction of the flange to provide a final continuous form of sealing member.

[0079] The forming operation may be carried out by a pressing apparatus 28 as illustrated in FIG. 9. The pressing apparatus may comprise a punch-die 29 having a continuous annular pressing surface 30 arranged for facing the deposited polymer mass 27. The pressing apparatus is also configured as an inverted cup with a central recess 31 to allow the cup-shaped body 1 of the container to be accommodated without pressure or deformation. As a result, the pressure applied by the punch-die is only focused on the thermoplastic material to be shaped into a final shape or at least semi-final shape of the sealing member. Pressing is applied while the thermoplastic polymer is still hot and plastically deformable without making crevasses or cracks, for example above or at its glass transition temperature. The apparatus may comprise a rod 33 connected to or part of a hydraulic or electrical ram (not represented) for instance. Cooling means may be embedded or associated to the pressing apparatus. For example, a fluid cooling circuit 32 can be managed within the punch-die.

[0080] FIGS. 10 to 20 illustrates various arrangements of the forming surface 30 of the punch-die of the pressing device for shaping the thermoplastic material into a sealing member. The forming surfaces may be arranged to deform, dimension and/or displace the material such that an optimal configuration of the sealing member is obtained as a result of the forming operation.

[0081] In the example of FIGS. 10 and 11, the forming surface 30 is generally convex so as to provide a sealing member with a concave sealing surface. Part of the sealing material can be moved to the transition area 12 of the container with some material covering an annular portion 34 of the side wall.

[0082] In the example of FIGS. 12 and 13, the forming surface 30 is generally flat so as to spread the sealing material flat over the flange so that it covers a larger surface while slightly reducing its thickness.

[0083] In the example of FIGS. 14 and 15, the forming surface 30 is generally concave so as to form a generally convex sealing member. The forming surface may further comprise two concave portions 35, 36 of surfaces thereby forming two circumferential ridges 37, 38 of sealing member 2. The two circumferential ridges 37, 38 may remain connected after forming (as illustrated) or, alternatively may be separated into two independent sealing portions during forming by a separating protrusion 39 of the forming surface 30.

[0084] In the example of FIGS. 16 and 17, the forming surface 30 is slanted in such a manner to move a major amount of sealing material towards the side wall. The forming surface may further be flat, convex or concave depending on the needs for shaping the optimal sealing design. In the example, the slanted surface is slightly convex so as to move and deform the sealing member such that it positions itself with the larger thickness present at the transition area 12 between the flange outer surface 11 and the side wall outer surface 8.

[0085] In the example of FIGS. 18 and 19, the forming surface has a general shape (e.g. flat, convex or concave) and a structuring finish. This structuring finish can be, for instance, a series of small circumferential parallel grooves 40. Many other structuring surfaces are possible.

[0086] For example, in FIG. 20, the forming surface of the punch-die is configured to form a plurality of small drops 41 in relief or in recess.