Patent Publication Number: US-10315791-B2

Title: Method and machine for making single use capsules for beverages

Description:
FIELD OF THE INVENTION 
     The present invention relates to a method and a machine for making single use capsules for beverages. 
     BACKGROUND OF THE INVENTION 
     There are known in the art single use capsules for extraction beverages of the type comprising, typically:
         a rigid body, cup—shaped, (usually, but not limiting, with a troncoconical shape) with a pierceable (or pre-pierced) bottom and an upper aperture provided with a rim;   a filtering element to define a containing chamber;   a dose of extraction product (for example in powder or granules) contained in the chamber and adapted to be contacted by a liquid under pressure;   a closing lid for closing the upper aperture of the rigid body and the chamber, adapted (usually, but not limiting) to be pierced by a nozzle for filling liquid under pressure.       

     The illustrated capsule is used in machines for making beverages comprising a housing for the capsules. 
     The closing lid of the capsule is usually pierced by a nozzle for filling liquid under pressure (hot water) that distributes on the product contained in the chamber in order to obtain the beverage. 
     The bottom of the rigid body is pierceable by means of different types of organs, like sharpened and hollow elements, adapted to penetrate the bottom and to guide the so obtained beverage towards a delivery nozzle. 
     A method and machine for making capsules of the type illustrated is known from EP-A-2093148. 
     The method (and machine) illustrated in EP-A-2093148 provides for cutting a portion of filtering material, suitably shaping the portion, and joining the shaped portion to an internal wall of the rigid body by means of radial sealers in two successive sealing stations. 
     The method (and machine) illustrated in EP-A-2093148 is quite complicated, because of the shaping and joining steps. In particular, it is quite complicated to join the portion, already shaped, of filtering material to the internal wall of the rigid body. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a method for making single use capsules for beverages that is simple, quick and precise. 
     It is a further object of the present invention to provide a machine for making single use capsules for beverages, carrying out the method of the invention, that is simplified and with high productivity. 
     The above objects are achieved by a method according to claim  1  and by a machine according to claim  10 . 
     In particular, a method according to the invention provides for a step of positioning a first strip of filtering material above rigid bodies, fed singly or in form of a second strip of thermoformed alveolate material; a step of joining the first strip of filtering material to rims of the rigid bodies; and a step of forming the first strip of filtering material to form a filtering element that defines a chamber for respective doses of product within respective rigid bodies. 
     Furthermore, a method according to the invention provides for filling the chambers with a respective dose of product and a step of closing the chambers with a respective closing lid. 
     Subsequently the step of joining, one or more steps of cutting are provided for cutting at least the filtering element, advantageously the filtering element and the closing lid. 
     Thus, the method according to the invention provides for joining the filtering material to the rigid body and, only subsequently, forming the filtering material to define the chamber. 
     The problem of accurate positioning the filtering element with respect to the rigid body of the known methods, that provide for thermoforming the filtering material before joining the filtering element to the rigid body, is thus overcome by the method of the invention. 
     The method according to the invention simplifies the step of positioning and joining the filtering element to the rigid body, as it provides for operating on plane surfaces both of the filtering element (fed through the first strip) and of the rigid body, in particular of the rim. 
     Moreover, the method according to the invention provides for cutting the filtering material only after the first strip is joined to the rim of the rigid body, so achieving an easier cutting of the filtering material, as the rim of the rigid body acts as an abutment element. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       These and other advantages of the invention will be clearly illustrated in the following detailed description and drawings of preferred embodiments, given by way of non limiting examples, wherein: 
         FIG. 1  is a schematic front view of a machine carrying out a method for making single use capsules for beverages of the extraction type according to the present invention, 
         FIG. 2  is a different embodiment of the machine of  FIG. 1 ; 
         FIG. 3  is a front view, with some parts cut away for sake of clearness, of a single use capsule for beverages made by the method and machine of the invention; 
         FIGS. 4 and 5  illustrate a step of forming a filtering element of a capsule in the machine of  FIG. 2 , in a schematic front view, with some parts cut away for sake of clearness; 
         FIGS. 6 and 7  illustrate a different embodiment of the step of forming the filtering element of  FIGS. 4 and 5 , in a schematic front view. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     According to the figures, in particular  FIG. 1 , a method according to the invention is carried out for making single use capsules  1  for beverages of the extraction or infusion type. 
     In particular (see  FIG. 3 ), the capsule  1  includes a rigid body  2 , that extends along a main direction Z, cup shaped and featuring a bottom  3  and an upper aperture, or mouth,  4 . The bottom  3  can be closed and pierceable, or pre-pierced. 
     The rigid body  2 , preferably, features a troncoconical section with the bottom  3  having smaller dimension that the upper aperture  4 . 
     The upper aperture  4  is delimited by a rim, or collar,  7 , that features an upper surface perpendicular to the main direction Z. Preferably, the rim  7  is circular and extends radially. 
     The upper aperture  4  of the rigid body  2  is engaged by a filtering element, or filter,  8  which is configured so as to extend, with a concave section, within the rigid body  2  to define a chamber  5  adapted to contain a dose D of product, for example in powder or granules. In particular, the filtering element  8  is coupled to the rim  7  of the upper aperture  4  of the rigid body  2 . The filtering element  8  is made of formable material, advantageously thermoformable material. 
     The capsule  1  further includes a closing lid  6  that closes the upper aperture  4  along the rim  7 . The closing lid  6  can be associated to the rim  7  only, or to the rim  7  and the filtering element  8 , or the filtering element  8  only. 
     The closing lid  6  can be rigid or flexible, air-tight or pre-pierced, depending on the machine for making beverages in which the capsule  1  is used. 
     The filtering element  8  allows to retain the dose D of product and to filter the beverage obtained towards the bottom  3  of the rigid body  2 . 
     The bottom  3 , if closed, is in turn pierced by means of organs adapted to direct the so obtained beverage to delivery nozzles. 
     According to the invention, the method for making capsules  1  includes, in sequence, the steps of (see  FIGS. 1 and 2 ):
         feeding a plurality of rigid bodies  2 ;   positioning a first strip S 1  of thermoformable filtering material above the rigid bodies  2 ;   firmly joining the first strip S 1  of thermoformable filtering material to the rigid bodies  2  at a joining zone along respective rims  7 ;   forming the filtering element  8  that defines the chamber  5  adapted to contain the dose D of product;   filling the chamber  5  with a dose D of product;   closing the chamber  5  and the upper aperture  4  of the rigid body  2  with a respective closing lid  6 .       

     In the step of feeding, it is possible to feed the rigid bodies  2  singly, for example by means of movable drawers  9  onto which suitable seats are achieved for the rigid bodies  2 . 
     Alternatively, in the step of feeding, it is possible to feed the rigid bodies  2  in form of a second strip S 2  of thermoformed material comprising an orderly plurality of rigid bodies  2 . The second strip S 2  may be continuous or discontinuous to form an alveolate band, or a plurality of alveolate trays, respectively. For example, the second strip S 2  can be moved by means of pull clamps  27  (schematically illustrated in  FIG. 1 ), or by means of the movable drawers  9 , or by means of suitable drawing rollers. 
     The method according to the invention further includes a step of cutting, to achieve single finished, capsules  1 . 
     According to a first alternative embodiment, a single step of cutting can be provided for downstream of the step of closing to cut the closing lid  6 , the first strip S 1  of filtering material and the rigid body  2  (in case the latter is fed in form of second strip S 2 ). 
     According to a different alternative embodiment, two or more steps of cutting can be provided. 
     For example, if the rigid bodies  2  are singly fed, a first step of cutting can be provided for immediately downstream of any one of the steps of joining, forming and filling to cut the first strip S 1  of filtering material, and a second step of cutting can be provided for downstream of the step of closing to cut the closing lid  6 . 
     According to a further embodiment, if the rigid bodies  2  are fed in form of second strip S 2  of thermoformed alveolate material, a first step of cutting can be provided for immediately downstream of any one of the steps of joining, forming and filling to cut the first strip S 1  and the second strip S 2  to form single rigid bodies  2 , and a second step of cutting can be provided for downstream of the step of closing to cut the closing lid  6 . 
     With such a succession of steps, it is possible to position and join (by means of sealing or hot or cold gluing, or by means of ultrasounds) the filter  8  to the rim  7  of the upper aperture  4  in an extremely simple and precise way, as in the step of positioning and in the step of joining the first strip S 1  and the rim  7  contact at respective plane and mutually parallel surfaces. 
     Furthermore, as the step of cutting is achieved downstream of the step of joining, it is possible to cut the first strip S 1  of filtering material in an extremely simple and effective way, even if material that are usually difficult to cut are employed, thanks to the rim  7  of the rigid body  2  that acts as abutment. 
     Only limited portions of the first strip S 1  of thermo formable filtering material are involved in the step of forming, in particular the portions of the first strip S 1  arranged at the upper apertures  4  of the rigid bodies  2  only. 
     Advantageously, the step of forming includes:
         a first sub-step of forming, or step of pre-forming, for partially forming the filtering element  8  towards the interior of the rigid body  2 , and   a second sub-step of forming, or step of final forming, for completely forming the filtering element  8 , so defining the chamber  5 .       

     Advantageously, in the step of pre-forming (see  FIGS. 4 and 6 ) an annular zone  8   a  of the filtering element  8 , adjacent and internal to the joining zone, is affected by a plastic deformation. 
     In the step of final forming, a central zone of the filtering element  8 , internal to the annular zone  8   a , is affected by a plastic deformation (see  FIGS. 5 and 7 ). 
     The step of forming in two subsequent sub-steps allows to modulate the plastic deformation of the filtering material, so avoiding risks of fractures and cracks. 
     Preferably, the step of forming the filtering element  8  is achieved by means of heat transfer. 
     It has to be noted that both the first sub-step and the second sub-step of forming are preferably achieved by means of heat transfer. 
     Advantageously, in the step of joining, the first strip S 1  of filtering material is joined to the rim  7  of the rigid body  2  by means of welding, i.e. through heat transfer, by means of hot or cold gluing, or by means of ultrasounds. 
     The present invention further provides a machine  100  for making the single use capsules  1  for extraction or infusion beverages. 
     The machine  100  includes a feeding system  40  for feeding a first strip S 1  of thermoformable filtering material; a transport system  50  for transporting the rigid bodies  2  along an advancing direction A, either singly or in form of a second strip S 2  of thermoformable material on to which an orderly plurality of rigid bodies  2  has been achieved; and a joining station  60  adapted to join the first strip S 1  to the rigid bodies  2  at a joining zone along respective rims  7 . 
     The second strip S 2  may be continuous or discontinuous, to form an alveolate band or a plurality of alveolate trays, respectively. 
     Downstream of the joining station  60 , the machine  100  includes a forming station  70  adapted to form the first strip S 1  of filtering material to achieve a filtering element, or filter,  8  that defines a chamber  5  adapted to contain a dose D of product. 
     Downstream of the forming station  70 , the machine  100  includes, in sequence, a filling station  80  adapted to fill the chamber  5  with a dose D of product and a closing station  90  adapted to close the chamber  5  with a closing lid  6 . 
     Advantageously, the machine  100  includes at least one cutting station  110 , integral with, or arranged downstream of, the closing station  90  adapted to cut the closing lid  6 , the first strip S 1  of filtering material and the second strip S 2  of thermoformable material to achieve single finished capsules  1 . In case the rigid bodies  2  are singly fed to the machine  100 , the cutting station  110  is adapted to cut the first strip S 1  of filtering material and the closing lid  6 . 
     In an alternative embodiment, the machine  100  may include a first cutting station arranged immediately downstream of any one of the joining station  60 , forming station  70  and filling station  80  and adapted to cut the first strip S 1  of filtering material and the second strip S 2  of thermoformable material (in case the rigid bodies  2  are fed in form of the second strip S 2 ), and a second cutting station integral with, or arranged downstream of, the closing station  90 , adapted to cut the closing lid  6 . 
     The feeding system  40  may comprise a feeding roll  25  for feeding the first strip S 1  of filtering material and a idle roller  26  adapted to make the first strip S 1  sliding upon the rigid bodies  2  along the advancing direction A. 
     The transport system  50  may comprise movable drawers  9  adapted to house in suitable seats, and to move, the rigid bodies  2 ; or, in the embodiment in which the rigid bodies  2  are fed in form of the second strip S 2 , one or more pull clamps  27  (schematically illustrated in  FIG. 1 ). In alternative embodiments not illustrated, the transport system  50  may comprise pulling rollers suitably shaped, at least one of which driven, to move the second strip S 2  along the advancing direction A. 
     The joining station  60  may comprise one or more joining sealers  61  shaped to join the first strip S 1  to the rim  7  of the rigid bodies  2  at an upper surface of the rim  7  that defines the joining zone. The joining sealers  61  can be reciprocatingly movable along a direction perpendicular to the advancing direction A of the first strip S 1  and the rigid bodies  2 . The joining station  60  may further comprise, below the rigid bodies  2 , an abutment element  62  for cooperating with the joining sealers  61 . Advantageously, in the embodiment illustrated in  FIG. 2 , the movable drawers  9  further acts as abutment element. 
     In an alternative embodiment, the joining station  60  may comprise a joining sealing roller, movable in rotation about an axis perpendicular to the advancing direction A. In such alternative embodiment, the same movable drawers  9  can act as abutment element, or the abutment element may assume the shape of a counter-roller, movable in rotation about an axis perpendicular to the advancing direction and parallel to the axis of rotation of the joining sealing roller. 
     The joining station  60 , in particular the joining sealers  61  and the joining sealing rollers, may operate in hot or cold conditions, or by means of ultrasounds. 
     The forming station  70  includes forming means  13  adapted to plastically deform the filtering material. 
     The forming means  13  includes a forming punch adapted to plastically deform the filtering element  8  to define the chamber  5 . 
     Advantageously, the forming means  13  includes a first, or pre-forming, punch  14  adapted to thermoform an annular zone  8   a  of the filtering element  8  adjacent and internal to the joining zone ( FIGS. 4 and 6 ), and a second, or final forming, punch  15  adapted to thermoform a central zone of the filtering element  8  internal to the annular zone  8   a  ( FIGS. 5 and 7 ). 
     The first punch  14  includes a heated ring element with a respective external contact surface, inclined and configured for thermoforming the annular zone  8   a  of the filtering element  8 . The first punch  14  is movable in a direction perpendicular to the advancing direction A, between an operative position wherein it contacts and thermoforms the first strip S 1  penetrating within the rigid body  2  and an inoperative position far away from the first strip S 1  and the rigid body  2 . In substance, the first punch  14  allows to obtain a sort of “flaring” of the filtering element  8  so as to prepare the filtering material in the annular zone  8   a  to the subsequent complete thermoforming, so avoiding tears and cracks. 
     The second punch  15  includes a forming head featuring a respective contact surface, for example hemispherical, adapted to contact and thermoform the central zone of the filtering element  8 , so as to define the chamber  5 . The second punch  15  is movable parallelly to the first punch  14  in direction perpendicular to the advancing direction A, between an operative position wherein it contacts and thermoforms the first strip S 1  penetrating within the rigid body  2  and an inoperative position far away from the first strip S 1  and the rigid body  2 . In substance, the second punch  15  completes the thermoforming of the filtering element  8 . 
     In the embodiment illustrated in  FIGS. 1, 2, 4 and 5 , the first punch  14  and the second punch  15  are coaxial and operatively coupled to pre-form and subsequently completely form the filtering element  8 . In detail, the second punch  15  is dimensioned to slide within the first punch  14 , after the latter has pre-formed the filtering element  8 . 
     In  FIGS. 6 and 7 , there is illustrated an alternative embodiment, in which the second punch  15  is arranged downstream of the first punch  14  along the advancing direction A. 
     In the embodiments illustrated in the figures, the second punch  15  does not contact the annular zone  8   a . In an alternative embodiment not illustrated, in case the first punch  14  and the second punch  15  are not coaxial, the second punch  15  may have dimensions adapted to contact both the central zone and the annular zone  8   a  of the filtering element  8 . 
     In embodiments not illustrated, the forming station  70  may comprise forming means with a single forming punch, adapted to thermoform the filtering element  8  in a single step. 
     The filling station  80 , arranged downstream of the forming station  70  along the advancing direction A, includes at least one dosing organ  21  positioned above the rigid body  2  and adapted to feed a dose D of product (for example in powder or granules) to the chamber  5 . 
     The closing station  90 , arranged downstream of the filling station  80  along the advancing direction A, includes coupling means  24  for coupling the closing lid  6  to the rigid body  2  at the rim  7 . In the illustrated embodiment, the closing lid  6  is fed in form of a third strip S 3  above the rigid bodies  2 . The coupling means  24  may comprise at least a sealing organ, reciprocatingly movable along a direction perpendicular to the advancing direction A and shaped for acting on the third strip S 3  in correspondence of the rim  7  of the rigid body  2 . The sealing organ may operate, for example, in hot or cold conditions, or by means of ultrasounds, to couple the closing lid  6  to the rim  7  only, or to the rim  7  and the filtering element  8 , or to the filtering element  8  only. Advantageously, the closing lid  6  is sealed to the filtering element  8  in correspondence of the rim  7  of the rigid body  2 . In an alternative embodiment not illustrated, the sealing organ may be shaped as a sealing roller, movable in rotation about an axis perpendicular to the advancing direction A. 
     A cutting station  110  may be integrated in to the closing station  90  and may comprise a cutting organ  111 , that operates in phase with the coupling means  24 , featuring a respective abutment element  112  (see  FIG. 1 ). 
     In the embodiment of  FIG. 2 , the movable drawers  9  can act as abutment element for the cutting organ  111 . 
     Alternatively, the cutting station  110  may be arranged downstream of the closing station  90  along the advancing direction A. 
     The third strip S 3  is fed by means of a roll  29 , while the scrap generated by the cutting station  110  is recovered by means of a further roll  30 . 
     The method and machine so conceived completely achieve the advantages set forth above. 
     The steps of joining and thermoforming the filtering element starting from a plane portion of filtering material allow to obtain a high quality capsule. In fact, by operating on plane surfaces, it is possible to position the chamber relative to the rigid body in a very precise way and to obtain a better perimetral joining between the filtering element and the rim.