Patent Publication Number: US-2016229624-A1

Title: Capsule For Beverages

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a national phase of PCT International Application No. PCT/1B2014/065358 filed Oct. 16, 2014. PCT/IB2014/0065358 claims priority to IT Application No. MO2013A000297 filed Oct. 17, 2013. The entire contents of these applications are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The invention relates to capsules or containers for preparing products, for example beverages, in automatic dispensing machines. 
     BACKGROUND 
     In particular, the invention relates to a single-dose and disposable sealed capsule containing an initial product such as, for example, powder coffee or an infusion product that is able to make a final product by interacting with pressurised fluid. 
     The known capsules for use in dispensing machines are disposable and single-dose containers comprising an outer casing, made of plastics impermeable to liquids and to gases and having a beaker or cup shape. 
       FIG. 3  shows a capsule  1  as disclosed in application ITMO2013A000214 of the same applicant. 
     The casing, indicated by  2 , has a base wall  3  and a side wall  4  defining an open cavity  5  into which a product P can be inserted, for example ground coffee or tea, from which the beverage can be obtained. A flange-shaped rim  7  is connected to the side wall  4 , extends therefrom and is arranged around an upper opening of the cavity  5 . The upper opening is hermetically sealed by a cover element  8 , typically an aluminium or plastics film, that is fixed to the edge  7  of the casing  2  so as to seal the product P inside the container. 
     The base wall  3  of the capsule  1  further has an opening, for example circular, bounded by an annular base rim  3   a  onto which a further cover element  25  is fixed, that is made of a material that is similar to the material of the cover element  8 . 
     The capsule is perforable to enable the pressurised liquid, typically water, to be delivered, and the obtained coffee beverage to exit. In particular, the further cover element  25  and cover element  8  are respectively perforable by a suitable pressurised fluid injecting arrangement and an extraction arrangement of a dispensing machine to enable the pressurised liquid to be delivered and the beverage to be extracted. 
     Alternatively, the capsule can also be inserted into dispensing machines of known type in which the cover element  8  and the further cover element are respectively perforable by a pressurised fluid injecting arrangement and an extracting arrangement of a dispensing machine. 
     In other words, both the cover element  8  and the further cover element  25  are made of an easily perforable material that causes the capsule to be able to be used with great flexibility of use in dispensing machines, regardless of whether the cavity faces upwards or downwards. 
     The capsules are usually filled with the initial product P by means of a manufacturing process that supplies the thermoformed casings to a filling station and subsequently supplies these filled casings to a welding station to seal the cavity by welding the cover element to the flange rim of the capsule, the further cover element having been already fixed to close the base rim  3   a . During this fixing of the cover element, into each capsule an inert gas such as nitrogen is delivered to replace the air to maintain the organoleptic properties of the initial product P unaltered owing to the inhibiting and bacteriostatic action of the gas used. 
     Nevertheless, if ground coffee is supplied to each casing, it is known that after roasting and grinding the coffee continues to be transformed even in the presence of the inert gas, releasing over time carbon dioxide and aromas in a ratio that is inversely proportionate to the time that has elapsed since roasting. For this reason, the ground coffee is usually subjected to a degassing step in storage silos, which is necessary for freeing the coffee from the carbon dioxide that is naturally released by the coffee. 
     SUMMARY 
     One problem of capsules of known type is that they can be filled with ground coffee that has not been subjected to the degassing step or has not been subjected to the degassing step is an efficient manner. In these capsules, the coffee can release carbon dioxide and can thus cause an unexpected increase of the pressure inside the capsule, which may cause deformations or an undesired swelling of the cover element and/or of the further cover element but which can even compromise the wholeness of the capsule, usually at the further cover element. 
     The excessive pressure can in fact cause tearing of the further cover element and the separation thereof from the base wall of the capsule, the further cover element being connected to the base wall by a welding rim that depends on the dimensions, which are often reduced, of the base wall. 
     The problem of the release of carbon dioxide is known not only for coffee, as said previously, but also for certain types of partially fermented tea, which may thus continue to ferment, releasing carbon dioxide also after the capsules have been filled. Also in this case, a filled capsule may break, due to the excessive build-up of pressure inside the capsule. 
     This problem is even greater if it is considered that after the capsules have been filled with the initial product P and packaged they may be stored for a long time in warehouses waiting to be distributed to consumers. A capsule may also break after the capsule has been purchased by a consumer and can thus cause damage in an uncontrolled manner. 
     One object of the present invention is to improve known capsules for beverages, in particular capsules that are usable in known dispensing machines, ensuring the wholeness of the capsule regardless of the initial product with which it is filled. 
     Another object is to devise a capsule that can be filled also with initial products that are able to release a gas after filling without the wholeness thereof being compromised over time. 
     A further object is to devise a capsule in which a closing element is fixed to a flange rim and a further closing element is fixed to the base wall, in which the further closing element does not separate from the base wall when subjected to pressure. 
     A still further object is to obtain a capsule that is cheap and easy to make. 
     According to a first aspect of the invention, a capsule for beverages is provided according to the independent claim and one or more of the claims appended thereto. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be better understood and implemented with reference to the attached drawings, which illustrate some embodiments thereof by way of non-limiting example, in which: 
         FIG. 1  is a schematic cross section, with parts removed for the sake of clarity, of a capsule according to the invention; 
         FIG. 2  is a partially enlarged schematic cross section of a base wall of the capsule in  FIG. 1 ; 
         FIG. 3  is a schematic cross section of a known capsule for beverages. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIG. 1 , there is illustrated a capsule  1  for beverages according to the invention, for producing a final product, in particular a hot beverage, for example coffee, barley, herbal tea, tea, chocolate, etc, by injecting a hot pressurised fluid F inside the capsule. 
     It is pointed out that for uniformity with the prior art capsule disclosed in  FIG. 3 , the same numeric references are assigned to the same components. 
     The capsule  1  of the invention comprises an outer casing or container  2 , in turn comprising a base wall  3  and a side wall  4  defining an open cavity  5  and that is suitable for containing an initial product P, for example a soluble or percolable food product to be combined with a fluid, typically water, to obtain a final product. The base wall  3  and the side wall  4  define a body of the capsule  1  substantially in the form of a beaker or cup. According to one embodiment, the base wall  3  is flat and in particular of circular shape. 
     The casing further comprises a flange rim  7  connected to the side wall  4  and extending therefrom, arranged around an upper opening of the cavity  5 . The flange rim  7  is further opposite the base wall  3  and faces outside with respect to the cavity  5 . 
     The base wall  3  of the capsule has an opening  30 , for example circular, bounded by a base rim  3   a , for example annular, extending up to the side wall  4  of the capsule and comprises an annular wall  31  that extends around the opening  30  inside the cavity  5  and defines a recessed portion of the base wall  3 , made in a single body with the base wall  3 . 
     The annular wall  31  has an inner end provided with a respective rim  31   a  facing a symmetry axis A of the capsule  1 , that bounds a hole  32  substantially of the same size as the opening  30 . The annular wall  31  defines in this manner a through conduit having the opening  30  that is an outer end opening, i.e. facing the outside of the capsule, on the side opposite the hole  32  of the inner end. 
     As shown in  FIG. 1 , the rim  31   a  of the annular wall  31  faces the portion of the cavity  5  intended for receiving the initial product P and contributes, if the base wall  3  of the capsule  1  is intended in use to be perforated by an injecting arrangement of the dispensing machine and the initial product is powder coffee, to maintaining said coffee powder compacted, avoiding preferential fluid paths being created therein that may give rise to a beverage of poor quality. It is in fact known that the pressurised fluid injected into the capsule has to be distributed as uniformly as possible in the initial product in order to be able to extract therefrom aromatic components to be transferred to the beverage, above all if the initial product is powder coffee. The through conduit defined by the annular wall  31  achieves in use a guiding element of an injecting arrangement of the dispensing machine. 
     The casing  2  is made by forming a sheet of thermoformable plastics (not shown) that is suitable for the process of preparing the final product from the initial product P, for example able to withstand temperatures up to 100° C. and pressures up to 5 bar without deformation. 
     Such a sheet of plastics  100  can have a thickness comprised between 15 micron and 1600 micron, in particular between 400 micron and 1200 micron and is made of polyolefins, for example polypropylene PP and/or polyethylene PE and/or polyamide PA. 
     In detail, the sheet material can comprise a first layer of material, in particular suitable for contacting and/or conserving the initial product P, for example made of polypropylene PP that is impermeable to humidity, a second layer of material that is not in contact with the initial product P made of a material that is impermeable to gases, in particular to oxygen and optionally also to humidity, also known as a barrier layer, and a third external layer of material. 
     The barrier layer, interposed between the first and the third layer, ensures the complete insulation of the cavity  5  from the outer environment, in particular if the first layer is permeable over time to oxygen. The barrier layer has a thickness comprised between 2 micron and 100 micron, in particular between 15 micron and 70 micron, and is made, for example, of ethylene vinyl alcohol (EVOH), which is gas-impermeable only to the oxygen or polyvinylidene chloride (PVDC), which is gas-impermeable to both oxygen and humidity. 
     According to a first embodiment (not shown) of the sheet material, the first and third layer are made of the same material, for example polypropylene PP and are coupled with the barrier layer interposed therebetween. These layers can have the same thickness (for example 350 micron), or different thicknesses (for example the first layer can have a thickness of 500 micron whereas the third layer can have a thickness of 300 micron). 
     According to a second embodiment (not shown), the first layer is a support and is made of polypropylene PP, the second layer is the barrier layer (EVOH or PVDC) and the third layer is an extruded layer of polypropylene PP or polyethylene PE, with a thickness of 15 micron, which is coupled with the first and the second layer during the process of manufacturing the sheet material. 
     The sheet material, both according to the first and the second embodiment, is thus selected so as to protect over time the initial product P contained in the capsule from humidity and oxygen. 
     The capsule further comprises a cover element  8  fixed to the rim  7  of the casing  2  to seal hermetically the capsule  1 , i.e. the open cavity  5  and thus preserve the product P. The cover element  8  comprises a film of aluminium or a plastic film provided with a barrier layer that is perforable by an extracting arrangement of the final product or by an injecting arrangement of the initial fluid F of the dispensing machine. 
     The cover element  8  is fixed to the rim  7  of the casing  2  by thermal or ultrasound welding or by gluing. In particular, the cover element  8  is fixed to the casing  2  by locking thermowelding, in the sense that this thermowelding ensures that the capsule conserves over time the initial product P in ideal conditions when stored during storage. 
     A closing element  26 , which is similar to the cover element  8  and is perforable by an injecting arrangement of the fluid F or by an extracting arrangement of the final product, is fixed to the further rim  3   a  outside the base wall  3 , to hermetically seal the opening  30 . As already said for the cover element  8 , the closing element  26  is fixed to the annular rim  3   a  by thermal or ultrasound welding or by gluing and in particular the closing element  26  is fixed to the casing  2  by locking thermowelding in a joining portion  33 . 
     The thickness of the cover element  8  and/or of the closing element  26  is expressed in grammage and is comprised between 5 and 120 g/m 2 . 
     According to the invention, the closing element  26  has greater dimensions than the base wall  3  and is also fixed to the side wall  4  to remain joined to the capsule even in the presence of a pressure increase inside the capsule, as will be seen below. 
     It should be noted that the base rim  3   a  defines a base edge  34  with the side wall  4  and that the closing element  26  extends beyond the base edge  34  and is superimposed on the side wall  4  along the entire base edge  34 , and namely angularly all around with respect to the symmetry axis A of the capsule. 
     The closing element  26  is superimposed and fixed to the side wall for at least one strip of 2 mm measured from the base edge  34 , in particular for 2.5 mm, but can be fixed to the side wall  4  for the entire side wall  4 . 
     If the closing element  26  is disc-shaped and the base wall is circular and flat, or a polygon that can be inscribed in a circle, the closing element  26  has a greater diameter than the base wall  3 . 
     The side wall  4  comprises a first portion  4   a  connected to the base edge  34  and a second portion  4   b  defining with the first portion a side edge  35 . The second portion  4   b  extends up to the flange rim  7 , as shown in  FIG. 1 . 
     It should be noted that the first portion  4   a  is of frustoconical shape and has a first tilt, which is greater than a second tilt of the second portion  4   b , which is also of frustoconical shape. The first and the second tilt are measured with respect to the symmetry axis A of the capsule. 
     Nevertheless, it is pointed out that the side wall  4  and thus the body of the capsule could be shaped differently and not have frustoconical portions but for example truncated-pyramid portions that can be inscribed into frustoconical portions. For example, the first portion could be truncated-pyramid and the second portion could also be truncated-pyramid, both, for example, with an octagonal base but with a different tilt. 
     Optionally, the side wall  4  of the capsule could also comprise a plurality of frustoconical or truncated pyramid portions with a gradually decreasing tilt and thus comprise a plurality of side edges. 
     In other words, although the closing element  26  is shown in  FIGS. 1 and 2  as associated with the casing  2  having a specific shape, the casing  2  could be shaped otherwise, with regard to the base wall  3 , the side wall  4  or the flange rim  7 , and everything said previously with regard to the closing element  26  would continue to be valid. 
     We have said that the closing element  26  is fixed to the base rim  3   a  and to the side wall  4  by thermowelding. 
     In detail, the closing element  26  is fixed to the side wall  4  in the entire first portion  4   a . In other words, the joining portion  33  by means of which the closing element  26  is thermowelded to the capsule  1  extends in the annular base rim  3   a , which is flat, and in the first portion  4   a  of the side wall  4 , oblique to the base rim  3   a , through the base edge  34  up to the side edge  35 . 
     Experimentally, it has been verified that the closing element  26  remains joined to the capsule even in the presence of a pressure increase inside the capsule because the joining portion  33  placed at the base rim  3   a  separates at pressure of about 2 bar whereas the joining portion  33  placed in the side wall  4  remains unchanged up to 4.5 bar, a pressure beyond which the casing  2  of the capsule  1  is torn together with the closing element  26 . 
     In detail it has been verified that:
         at 0.5 bar the closing element  26  shows a swelling but the joining portion  33 , placed in the base rim  3   a  and in the first portion  4   a , remains unchanged;   at 1 bar the joining portion  33  placed in the base rim  3   a  starts to separate but the joining portion placed in the first portion  4   a  remains unchanged;   at about 2 bar the joining portion  33  placed in the base rim  3   a  separates but the joining portion placed in the first portion  4   a  remains unchanged;   up to 4.5 bar the joining portion  33  in the first portion  4   a  remains unchanged;   beyond 4.5 bar the closing element  26  and the casing  2  are torn by excessive pressure but the thermowelding in the joining portion  33  through which the closing element  26  is joined to the capsule  1  remains unchanged.       

     Up to 4.5 bar, it is thus ensured that a circumferal rim of the closing element  26  remains joined to the capsule, in particular to the side wall  4  thereof, by locking thermowelding ensuring the wholeness of the capsule even at high pressures. 
     It has in fact been observed that the pressure released inside the cavity  5  of the capsule stresses the closing element  26  perpendicularly at the opening  30  and this causes the joining portion to be pushed in a direction that is orthogonal to the welding plane in the base rim  3   a.    
     Nevertheless, the joining portion  33  is stressed only obliquely at the first portion  4   a , after the base rim  3   a  has been separated, because the closing element  26  continues to be pushed mainly perpendicularly at the opening  30  by the pressure inside the capsule. 
     Owing thus to the fact that the closing element  26  is fixed both to the base rim  3   a  and to the side wall  4 , a capsule can also be filled with an initial product that releases gas inside the capsule, because both the cover element  8  and the closing element  26  can withstand high pressure without compromising the wholeness of the capsule. 
     It follows that the capsule can also be filled with coffee that has not been completely degassed, because the higher pressure that may develop inside a capsule is less than the pressure at which the closing element  26  separates from the capsule. The capsule of the invention thus remains sealed even after a time has elapsed since the filling thereof, regardless of the initial product with which the capsule is filled (ground coffee degassed or not or tea) and regardless of the moment at which it is consumed by the user. 
     Further, the process of manufacturing each capsule becomes cheaper because it is no longer necessary to subject the ground coffee to a degassing step but it is possible to fill the capsules with coffee that has just been roasted and ground.