Method for packaging products, particularly portions of chocolate or the like, and facility for implementing the method

Abstract

The invention relates to a method and facility for packaging products ( 10 ), said facility comprising a linear transporter ( 20 ) that includes a set of endless conveyor belts ( 20 a ) associated with a belt having synchronizing cleats ( 20 b ), with a linear pusher ( 20 c ) actuated by a parallelogram mechanism ( 20 d ) imparting rectilinear motion thereto, as well as with a counter-pusher ( 20 e ) which is provided for gripping the product and the sheet of packaging material, and which is driven by a cam or the like. The products are placed in one of the receiving jaws ( 21 a ) of a first revolver ( 21 ) so as to enter a first heat-sealing station ( 30 ) which is designed to seal the fold along the longitudinal edge of the product ( 10 ). At the outlet of a folding box, the products are transferred into the recesses ( 23 a ) of a second revolver ( 23 ) which rotates in the direction opposite the direction of rotation of the first revolver ( 21 ). The products are consecutively conveyed into three identical stations ( 40, 41 and 42 ) for heat-sealing the end folds, wherein all of the stations consecutively receive the same products. The reason for said plurality of stations is due to the fact that the end folds have more than two sheets of packaging material, and the greater the number of pieces of material, the longer the heat-sealing step takes.

1 . A method for packaging products, in which a product ( 10 ) is carried on a linear transporter ( 20 ) and a sheet ( 11 ) cut in a strip of heat-sealable packaging material is interposed on a trajectory of said product, the method comprising:
 inserting said product ( 11 ) and the sheet of heat-sealable packaging material ( 11 ) simultaneously into a first rotary transporter, called a first revolver ( 21 ), while folding this sheet in a U around said product so as to form two flaps ( 12   a,    12   b ) called longitudinal flaps of unequal lengths, adjacent to one side of the product,   carrying said product and its packaging in this configuration to at least one first heat-sealing station ( 30 ) in which the two flaps ( 12   a,    12   b ) are welded in order to produce a leakproof seal called a longitudinal seal along said side of the product and to form a longitudinal flap ( 16 ),   at the exit of said first revolver ( 21 ), transferring said product and its longitudinally sealed packaging into a folding box ( 31 ) in order to form lateral folds called end folds ( 14 ,  15 ),   transferring said product in its longitudinally sealed configuration and comprising end folds into a second rotary transporter called a second revolver ( 23 ), associated with at least two pairs of heat-sealing stations ( 40 ,  41 ,  42 ),   carrying the product successively into each of said at least two pairs of heat-sealing stations in order to complete the leakproof seal around said product,   at the exit of said second revolver ( 23 ), folding down the lateral folds and the longitudinal flap ( 16 ), and   discharging the packaged product in a sealed manner while keeping said longitudinal flap ( 16 ) pressing on the packaging of said product.   
     
     
         2 . The method as claimed in  claim 1 , characterized in that said first revolver ( 21 ) is used exclusively for carrying out the longitudinal sealing of the packaging of the product and said second revolver ( 23 ) exclusively for carrying out the sealing of the end folds ( 14 ,  15 ) of the packaging of the product. 
     
     
         3 . The method as claimed in  claim 1 , characterized in that the end folds ( 14 ,  15 ) of the packaging of the product are fashioned in a folding box ( 31 ) which is interposed between said first revolver ( 21 ) and said second revolver ( 23 ). 
     
     
         4 . The method as claimed in  claim 1 , characterized in that said first revolver ( 21 ) and said second revolver ( 23 ) are driven in directions counter to one another. 
     
     
         5 . The method as claimed in  claim 1 , characterized in that said product ( 10 ) and the sheet of heat-sealable material ( 11 ) that is associated therewith are made to travel from an entrance zone in said first revolver ( 21 ), through the heat-sealing station ( 30 ) in order to seal said longitudinal edges of the flaps ( 12   a,    12   b ) to an exit zone of this first revolver in a time equal to that during which said product and the sheet of heat-sealable material that is associated therewith travel from an entrance zone ( 22 ) in said second revolver ( 23 ), through three successive heat-sealing stations ( 40 ,  41 ,  42 ) in order to seal said end folds ( 14 ,  15 ) into an exit zone ( 24 ) of this second revolver ( 23 ). 
     
     
         6 . The method as claimed in  claim 1 , characterized in that the end folds ( 14 ,  15 ) and the longitudinal flap ( 16 ) are folded down at the exit of said second revolver ( 23 ). 
     
     
         7 . The method as claimed in  claim 1 , characterized in that the packaged product is discharged after the bonding of said longitudinal flap ( 16 ) by means of a conveyor band ( 60 ) and a pressure belt ( 60   a ). 
     
     
         8 . The method as claimed in  claim 7 , characterized in that the conveyor band ( 60 ) and the pressure belt ( 60   a ) are driven at a speed higher than that of an exit pusher ( 50   g ) of the second revolver ( 23 ). 
     
     
         9 . A facility for packaging products, in a sealed packaging, for the implementation of the method as claimed in  claim 1 , this facility comprising a linear transporter ( 20 ) arranged to move said product and a device for interposing the sheet cut in a strip of heat-sealable packaging material on the trajectory of said product, characterized in that the device comprises first means arranged for simultaneously inserting said product ( 10 ) and said sheet of heat-sealable packaging material ( 11 ) into the first revolver ( 21 ), and for folding this sheet of heat-sealable packaging material ( 11 ) in a U around said product ( 10 ) so as to form the longitudinal flaps, of unequal lengths, adjacent to the one side of the product ( 10 ), at least one heat-sealing station ( 30 ) for welding the two flaps ( 12   a,    12   b ) while producing the longitudinal seal, along said side of the product and to form the longitudinal flap ( 16 ), a folding box ( 31 ) arranged to form the end folds ( 14 ,  15 ), placed at the exit ( 22 ) of said first revolver ( 21 ), second means arranged to transfer said product ( 10 ) in its longitudinally sealed configuration and comprising the end folds ( 14 ,  15 ) into the second revolver ( 23 ), at least two pairs of heat-sealing stations ( 40 ,  41 ,  42 ) placed at the a periphery of said second revolver ( 23 ), third means arranged, at the exit ( 24 ) of said second revolver ( 23 ), to fold down the end folds ( 14 ,  15 ) and the longitudinal flap ( 16 ), and fourth means arranged for discharging the packaged product in a sealed manner while keeping said longitudinal flap ( 16 ) pressing on the packaging of said product ( 10 ). 
     
     
         10 . The facility as claimed in  claim 9 , characterized in that said second revolver ( 23 ) is associated with three heat-sealing stations ( 40 ,  41 ,  42 ) placed after one another and arranged so that each carries out a partial sealing of the end folds ( 14 ,  15 ) of one and the same product ( 10 ). 
     
     
         11 . The facility as claimed in  claim 9 , characterized in that said folding box ( 31 ) is interposed between said first revolver ( 21 ) and said second revolver ( 23 ), the exit ( 22 ) of said first revolver ( 21 ) corresponding to the entrance into the folding box ( 31 ) and the exit of the folding box ( 31 ) corresponding to the entrance into the second revolver ( 23 ). 
     
     
         12 . The facility as claimed in  claim 9 , characterized in that said first revolver ( 21 ) comprises first, second, third, fourth, fifth and sixth sets of pincers ( 21   a ) separated angularly by an angle of 60°, the first set of pincers corresponding to an entrance zone of the revolver ( 21 ), the second set to a waiting and holding zone of the product ( 10 ) with said thermoformable sheet ( 11 ), the third set to a heat-sealing station ( 30 ) along the longitudinal edge of the product, the fourth set to an exit zone ( 22 ) of this first revolver ( 21 ) and the fifth and sixth sets of pincers corresponding to positions of return on empty to said entrance zone. 
     
     
         13 . The facility as claimed in  claim 9 , characterized in that said second revolver ( 23 ) comprises first, second, third, fourth, fifth, sixth, seventh and eighth cavities ( 23   a ) separated angularly by an angle of 45°, the first cavity corresponding to an entrance zone ( 22 ) of the revolver, the second cavity to a waiting and holding zone of the product ( 10 ), the third, fourth and fifth cavities to the three successive heat-sealing stations ( 40 ,  41 ,  42 ) arranged to seal said end folds ( 14 ,  15 ), the sixth cavity to an exit zone ( 24 ) of this second revolver ( 23 ) and the seventh and eighth cavities to positions of return on empty to said entrance zone ( 22 ). 
     
     
         14 . The facility as claimed in  claim 9 , characterized in that the exit station ( 50 ) comprises an axial motion pusher ( 50   g ) of which the function consists in ejecting the product ( 10 ) onto a discharge conveyor band ( 60 ). 
     
     
         15 . The facility as claimed in  claim 14 , characterized in that the exit station ( 50 ) also comprises a pressure belt ( 60   a ) which interacts with said conveyor band ( 60 ) to press on the product and its packaging and allow the time for a sealing adhesive to take in order to ensure the closure of said packaging.