Machine for packing food products in containers

Abstract

A machine for packing food products (2) in containers (3) defined by respective trays (4) sealed by respective sealing films (8) has a glue application station (18) for applying a layer of glue (20) on an upper peripheral edge (7) of each tray (4), a first control station (24) for controlling the continuity and integrity of the layer of glue (20), a filling station (26) for feeding at least one food product (2) into the tray ( 4 ), a sealing station (28) for glueing the sealing film (8) on the upper peripheral edge (7) and for sealing the container (3), and a second control station (29) for controlling the continuity and integrity of the glueing of the sealing film (8) on the upper peripheral edge (7) itself.

Description

[0001] Title : Machine for packing food products in containers

[0002] DESCRIPTION

[0003] The present invention relates to a machine for packing food products in containers .

[0004] In the field of packing food products in related containers , it is known to make a machine of the type comprising an input station adapted to receive a succes sion of trays , each of which is made of a polymeric material , is delimited by a bottom wall and by a side wall and has an upper peripheral edge provided with a layer of non-stick material .

[0005] The machine further comprises a removal station for removing the layer of non-stick material from the upper peripheral edge ; and a glue application station for applying a layer of glue directly onto the polymeric material of the upper peripheral edge .

[0006] Moreover, the machine has a control station provided with a video camera to control the continuity and integrity of the layer of glue applied on the upper peripheral edge ; a filling station for feeding at least one food product into the tray; and a sealing station for gluing a seal ing film on the upper peripheral edge and for sealing the related container .

[0007] The known machines for packing food products in containers of the above-described type have some drawbacks mainly deriving from the fact that said machines , although highly tested, are unable to control the correct glueing of the sealing film on the outer peripheral edge and, thus , the correct sealing of the container .

[0008] An obj ect of the present invention is to provide a machine for packing food products in containers that is free from the above-mentioned drawbacks and that is simple and of economical implementation .

[0009] According to the present invention a machine for packing food products in containers is made according to what is claimed in the appended claims .

[0010] The present invention will now be described with reference to the enclosed drawings , which illustrate a nonlimiting embodiment , wherein : figures la to 1g schematically illustrate , in a top side view with parts removed for the sake of clarity, a preferred embodiment of the machine of the present invention; figures 2 and 3 are two schematic plan views , with parts removed for the sake of clarity, of two details of figure 1 ; and figures 4 , 5 , and 6 schematically illustrate , in perspective view, three production steps of the container made in the machine of figures 1 , 2 , and 3 .

[0011] With refence to figures 1 to 6 , reference number 1 globally indicates a machine for packing food products 2 in related containers 3 .

[0012] Each container 3 comprises a tray 4 of polymeric material , which is cup-shaped for housing at least one food product 2 therein, is delimited by a bottom wall 5 and is further delimited by a ring-closed side wall 6 about the wall 5 itsel f .

[0013] The tray 4 has an upper peripheral edge 7 substantially plane , which is obtained along the wall 6 and is sealed, once the food product 2 has been inserted, by a sealing film 8 glued along the edge 7 itsel f .

[0014] The tray 4 is made from a sheet 9 , which is separated by a tape 10 delimited by two faces 11 opposite each other and is unwound from a coil 12 .

[0015] To prevent the layers of tape 10 wound on the coil 12 from adhering to each other, the tape 10 is provided with a layer of non-stick material (not illustrated) applied on one of the faces 11 (hereinafter indicated with I la ) .

[0016] When the tape 10 is wound on the coil 12 , the layer of non-stick material (not shown) applied on the face I la comes into contact with the other face 11 (hereinafter indicated with 11b ) and is trans ferred at least in part onto the face 11b itsel f .

[0017] The machine 1 comprises an input station 13 adapted to receive in input a succession of trays 4 coming from a stack (not illustrated) of trays 4 or from a forming machine (not illustrated) of the trays 4 themselves .

[0018] Each tray 4 is fed, speci fically with its concavity facing downwards , through a removal station 14 provided with a laser device 15 configured to remove a layer 16 of non-stick material present on the edge 7 .

[0019] According to a variant not illustrated, the layer 16 present on the edge 7 is removed through a chip extraction machining, for instance a grinding treatment performed by a grinding roller mounted to rotate about a rotation axi s transversal to a tray 4 feeding direction 17 .

[0020] In this regard, it is worth speci fying that the edge 7 is quadrilateral-shaped and comprises two longitudinal portions 7a substantially parallel to the direction 17 and two transversal portions 7b substantially transversal to the direction 17 itsel f .

[0021] Once the layer 16 has been removed, the tray 4 is fed in the direction 17 through a glue application station 18 provided with an applicator rol ler 19 adapted to apply a layer 20 of glue directly onto the polymeric material of the edge 7 and without the interpos ition of the layer 16 itsel f .

[0022] The roller 19 is mounted below the tray 4 to rotate about a rotation axis 21 , which extends parallel to a containment plane of the edge 7 and is tilted according to an angle other than 90 ° relative to the direction 17 .

[0023] Regarding the above , it is worth speci fying that : the layer 20 is appl ied along the entire edge 7 and onto at least part of the width thereof ; the layer 20 applied by the roller 19 on the edge 7 , due to the intrinsic characteristics of the roller 19 , has a non-uni form thickness and an alternation of glue areas 22 of greater thickness and glue areas 23 of thinner thickness ; and the areas 22 and 23 are substantially transversal to the axis 21 and oriented according to an angle other than 0 ° relative to the direction 17 .

[0024] Afterwards , the tray 4 is rotated with its concavity facing upwards and fed through a first control station 24 provided with a video camera 25 to control the integrity and correct application of the layer 20 on the edge 7 .

[0025] When the image acquired by the video camera 25 has , parallel to the direction 17 , an alternation of areas 22 and areas 23 , the layer 20 has been applied correctly by the roller 19 on the edge 7 and the tray 4 passes the inspection of the video camera 25 without being discarded .

[0026] In this regard, it is worth speci fying that the station 24 is further provided with a first discard device (not illustrated) for discarding trays 4 in response to a signal of the video camera 25 . At this point , the tray 4 is fed in succession first of all through a fill ing station 26 , at which the tray 4 receives a sheet 27 of absorbent paper and at least one food product 2 , and then through a sealing station 28 , at which the tray 4 is sealed by fixing the related seal ing film 8 on the edge 7 through the layer 20 of glue .

[0027] Finally, the newly sealed container 3 is fed through a second control station 29 provided with a video camera 30 to control the gluing of the film 8 along the edge 7 .

[0028] When the video camera 30 detects a continuous gluing of the film 8 along the entire edge 7 , the container 3 is considered suitable and marketed and the image acquired by the video camera 30 is stored in the memory of an electronic control unit (not shown) of the machine 1 .

[0029] When the video camera 30 detects at least one discontinuity in the gluing of the film 8 along the edge 7 , the container 3 is not sealed, the internal chamber of the container 3 communicates with the external environment thus compromising the integrity of the food product 2 , and the container 3 is discarded .

[0030] In this regard, it is worth speci fying that the station 29 is further provided with a second discard device (not illustrated) to discard the containers 3 in response to a signal of the video camera 30 .

[0031] The control of the integrity of the layer 20 of glue applied on the edge 7 of the tray 4 through the video camera 25 and of the integrity of the gluing of the seal ing film 8 on the edge 7 of the tray 4 through the video camera 30 is allowed by the presence in the layer 20 of glue of luminophoric substances , i . e . substances capable of emitting light at room temperature , in particular when activated by an ultraviolet light source .

[0032] In particular, the luminophore substances have wavelengths between 250 nm and 600 nm, and the glue of the layer 20 has a viscosity between 500 mPas and 1600 mPas .

Claims

CLAIMS1.- A machine for packing food products (2) in containers (3) , the machine comprising an input station (13) adapted to receive a succession of trays (4) , each one is made of a polymeric material, is delimited by a bottom wall (5) and by a side wall (6) and has an upper peripheral edge (7) ; a glue application station (18) for applying a layer of glue (20) onto the upper peripheral edge (7) ; a filling station (26) for feeding at least one food product (2) into the tray (4) ; a first control station (24) mounted between the glue application station (18) and the filling station (26) for controlling the continuity and integrity of the layer of glue (20) applied on the upper peripheral edge (7) ; and a sealing station (28) for glueing a sealing film (8) on the upper peripheral edge (7) and for sealing the related container (3) ; and being characterized in that it further comprises a second control station (29, 30) mounted downstream of the sealing station (28) for controlling the continuity and integrity of the gluing of the sealing film (8) on the upper peripheral edge (7) , and in that, when said second control station (29, 30) detects a continuous gluing of said film (8) along the entire edge (7) , the container (3) is considered suitable and marketed and the image acquired by said second control station (29, 30) is stored in the memory of an electroniccontrol unit of said machine.2.- The machine according to claim 1, wherein the first control station (24) is provided with a first detection device (25) , in particular a first video camera, and with a first discard device to discard the trays (4) in response to a signal of the first detection device (25) .3.- The machine according to claim 1 or 2, wherein the second control station (29) is provided with a second detection device (30) , in particular a second video camera, and with a second discard device to discard the containers (3) in response to a signal of the second detection device (29) .4.- The machine according to claim 3 and further comprising an electronic control unit provided with a memory to store at least part of the signals coming from the second detection device (30) , in particular at least part of the images acquired by the second video camera.5.- The machine according to any one of the preceding claims, wherein the glue application station (18) is provided with an applicator roller (19) mounted so as to rotate about a rotation axis (21) oriented according to an angle other than 90° relative to a feeding direction (17) of the trays (4) through the glue application station (18) .6.- The machine according to claim 5, wherein the upper peripheral edge (7) comprises two longitudinalportions (7a) substantially parallel to each another and to the feeding direction (17) and two transversal portions (7b) substantially parallel to each another and transversal to the feeding direction (17) ; the applicator roller (19) having a width, measured transversally to the feeding direction (17) , rounding up a width of the tray (4) , which is also measured transversally to the feeding direction (17) .7.- The machine according to any one of the preceding claims and further comprising a removal station (14) mounted between the input station (13) and the glue application station (18) to remove a layer of non-stick material (16) applied on the upper peripheral edge (7) of the trays ( 4 ) .8.- The machine according to claim 7, wherein the removal station (14) is provided with a laser device (15) or with a plasma device or with a corona discharge device or with a tool device for chip removal.9.- The machine according to any one of the preceding claims, wherein the layer of glue (20) has a viscosity ranging, in particular, from 500 mPas to 1600 mPas and contains luminophore substances having wavelengths ranging, in particular, from 250 nm to 600 nm.

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