WO2009092966A1

WO2009092966A1 - Method for packaging a pasty product in an easily opened, sealed packaging made of plastic material

Info

Publication number: WO2009092966A1
Application number: PCT/FR2009/050055
Authority: WO
Inventors: Jean-Claude Weber; Léonard DIDIOT
Original assignee: Fromageries Bel
Priority date: 2008-01-25
Filing date: 2009-01-15
Publication date: 2009-07-30
Also published as: ES2369342T3; PL2238037T3; EP2238037B1; FR2926792A1; EP2238037A1; ATE523431T1; FR2926792B1

Abstract

The invention relates to a method for packaging a pasty product such as processed cheese or fresh processed cheese in an easily opened, sealed packaging made of two thin sheets of a plastic material, i.e. a first sheet (4) defining a cup (8) having a bottom (80) and side surfaces (81) and a second sheet defining a lid (13) tightly sealed to the edges (81A) of the cup, wherein said method comprises: cutting the first sheet (4) along an adapted outline; conforming the first sheet (4) by folding in order to form a cup (8) having side surfaces (81) extending beyond the cup filling area; filling the cup filling area with a pasty product; placing on the free surface of the pasty product (11) the second sheet cut so as to form a lid (13); and sealing the lid (13) on the side surfaces (81). Before shaping the first sheet (4) by folding, the sheet (4) is heated at selected areas (5) so as to carry out thermoforming during the folding operation.

Description

Process for packaging pasty product in an easy opening plastic sealed package.

The present invention relates to the packaging of a pasty product such as a processed cheese or a fresh cream cheese or a fresh cheese in an easy opening sealed packaging package consisting of two sheets, a first sheet constituting a cup having a bottom and side faces, and a second sheet constituting a lid sealingly sealed to the edges of the bucket.

Packaging of portions of pasty product, such as a processed cheese or a melted fresh cheese, consisting of sheets shaped so as to form a shell and closed by a lid, the sheets being sealed so as to ensure a tight closure, are known. Such packages generally include a ribbon for easy opening. They are generally made of aluminum and make it possible to form rectangular portions or triangular portions.

For reasons such as energy saving reasons, it is advantageous to be able to replace aluminum with less energy consuming materials such as plastics such as polypropylene. For this, it has been proposed to produce pasty plastic packaging packaging that requires the use of suitable equipment to overcome the disadvantages of these materials that do not keep the memory of the folds they have been subjected to . This is particularly the case of patent EP 08 03 439 in which a method and an installation for producing a package for packaging pasty materials from three sheets of plastic material which are shaped and assembled using installations with heated bending tools for hot bending. This technique has disadvantages in particular because it requires either the establishment of specific equipment leading expensive investments or making significant changes to existing machines designed for the material such as aluminum. In addition, this method allows heating only an outer face of the bucket and not the sealing lacquer that can be disposed on the inner face thereof, which complicates the sealing operations of the package. The object of the present invention is to remedy these drawbacks by proposing a method which makes it possible to manufacture packagings of pasty products, such as a processed cheese or a fresh cheese or a fresh cheese, from sheets of material plastic and which requires little modification of known packaging facilities.

For this purpose, the invention has the effect of a method for packaging a pasty product such as a processed cheese or a fresh cheese or a fresh cheese cheese in an easy opening sealed packaging package consisting of two thin sheets of material plastic, a first sheet constituting a cup having a bottom and side faces and a second sheet constituting a lid sealingly sealed to the edges of the cup, according to which:

the first sheet is cut into an appropriate contour;

- The first sheet is folded to form a bucket whose side faces extend beyond the filling area of the bucket;

- Filling the filling area of the bucket with pasty product;

on the free surface of the pasty product contained in the cup, the second cut sheet is placed at dimensions at least equal to those of the bottom of the cup so as to form a lid, and the cover is sealed on the lateral faces.

Before forming the first sheet by folding, the sheet is heated in selected areas to allow thermoforming during folding.

The heating of the sheet may be effected by contact with at least one hot plate recessed in the parts to be saved or by infrared radiation or by blowing hot air.

Before forming the bucket, it is possible to fix on the first sheet at least one easy opening strip.

Preferably, the first sheet has a heat-sealable lacquer on the face intended to be located inside the package and is cut so that, after forming the bucket at least a first side face has a tab of which the inner face comes into contact with the outer face of a second side face of the bucket and sealed by heat-sealing the tab on the second side face. To form the first sheet by folding, it can be grasped with a piston provided with suction holes, then pass through a forming shaft of a bucket having at its base pressure rollers with which the lateral faces of the bucket can be clamped so as to form the folds and possibly thermo-seal a tab of a lateral face of the bucket against another lateral face of the bucket.

Preferably, after forming the bucket, the bucket is transferred into a cavity having suction holes at its periphery, and the lateral faces of the bucket are pressed against the side faces of the cavity by suction and the suction is maintained for the filling of the bucket.

To set up and seal the lid, you can proceed as follows:

the second sheet is grasped by means of a piston provided with suction holes; with the aid of the piston, the second sheet is passed through a forming plate so as to give the lid a concave shape with a small peripheral rim;

- The lid is deposited in contact with the upper face of the product contained in the bucket; - Sealing the lid edges on the side faces of the bucket by clamping outer heating jaws against the piston; and

- The flanges of the side walls of the bucket are folded against the upper face of the lid and sealed by heat sealing with a heating pad. Preferably, at least the first sheet is polypropylene, optionally oriented, and has on one of its faces a thermo sealable lacquer layer.

The method can be implemented by an installation which comprises in particular: a preheating station before forming a cut sheet intended to be formed to form a bucket;

- a forming station of a bucket comprising a forming piston and a forming chimney; a cell for receiving and transferring a bucket.

Preferably, the piston of the forming station comprises means for holding, in particular by suction, a sheet against the piston, and the forming chimney comprises at its base lateral clamping means of a sheet being formed against the lateral faces of the piston.

The lateral clamping means arranged at the base of the forming chimney consist for example of rollers mounted on adjustable elastic means.

The receiving cell has at its periphery suction means adapted to press the lateral faces of a bucket against the lateral faces of the cell.

The installation may also include one or more of the following:

unwinding a plastic strip and cutting a first or second sheet,

- easy opening tapes,

- filling a bucket;

- placing a lid and sealing the lid using heated jaws, - folding and sealing the edges of the bucket.

The invention will now be described in a more precise but nonlimiting manner with reference to the appended figures in which:

- Figure 1 is a top view of a first plastic sheet for constituting a bucket for packaging packaging a pasty product;

- Figure 2 is a schematic representation of a preparatory operation for the manufacture of the package which consists of unwinding and a first packaging of a plastic sheet;

FIG. 3 is a view from above of a plastic sheet intended to constitute the cup of a package for packaging a pasty product showing zones which are preheated before folding;

- Figure 4 is a schematic representation of the first three manufacturing operations of a conditioning package of a pasty product; - Figure 5 is a schematic sectional view of a forming plant of a first plastic sheet for constituting the bucket packaging packaging a pasty product;

- Figure 6 is a schematic view of the fourth operation of the packaging and packaging a pasty product which consists of filling a bucket with pasty products;

FIG. 7 is a schematic representation of the operation of placing the closing lid of the pasty product packaging packaging; - Figure 8 is a schematic representation of the welding operation of the lid edges on the edges of the bucket of a packaging packaging a pasty product;

- Figure 9 is a schematic view of the operation of folding and sealing the upper edges of the bucket packaging packaging a pasty product; and

- Figure 10 is a schematic representation of a portion of parallelepiped-shaped molten cheese packaged in a plastic packaging packaging.

To produce a packaging for packaging a pasty product, such as a processed cheese or a fresh cheese or a fresh cheese, rolls a roll 1 of a sheet 2 made of plastic such as polypropylene or oriented polypropylene of which one of the faces is covered with a thermo-sealable lacquer. On this sheet of plastic material, first of all, easy opening ribbons 3 are deposited, for example in the form of a tuning fork. Once these easy-opening ribbons are set, a first sheet 4 is cut from the plastic sheet to give it an appropriate contour allowing folding to form a bucket having a bottom and side faces that can be assembled by thermo-plastic. -sealing.

An example of cutting to make a cup square section is shown in Figure 1. The sheet 4, generally cross-shaped, consists of a central portion 40 for forming the bottom of the bucket which is surrounded by flaps 41 , 42, 43 and 44 for forming after folding around the fold lines 45, 46, 47 and 48 to form the side faces of the bucket. In order to To facilitate the subsequent folding, the fold lines are pre-marked during cutting by using adapted blades by means of which pressure is exerted on the sheet.

In the corners 49 which are located between two adjacent flaps, for example between the flap 44 and the flap 41, the sheet is cut so as to form two lugs 50 and 51 separated by a diagonal fold line 52. The lug 50 is adjacent at the flap 41 and the tab 51 is adjacent to the flap 44. The cutting is adapted so that the tab 50 and the tab 51 are of different size, in particular for the tabs 51 to be larger than the tab 50, so that that when the flaps 41 and 44 are folded upwards to form the side faces of the bucket, the tab 51 comes to cover the tab 50 and extends beyond the tab 50 so that its inner zone 53 can come in contact with the outer face of the flap 41. Thus, the plastic sheet being covered with thermo-sealable lacquer on its inner face, the portion 53 of the lug 51 may be glued by heat-sealing on the outer face of the flap 41 .

Naturally, the four corners of the sheet are cut in the same way, in order to thermally seal each of the edges of the bucket.

This cutting operation, which has been marked O1 in FIG. 4, is followed by a second operation O2 for preheating the first sheet of plastic material 4 so as to create heating zones 5 which cover the fold lines according to which the folding will be The heating zones, shown in more detail in FIG. 3, are in the form of lattices and cover fold lines 45, 46, 47 and 48 and leave a central zone free. and median areas in the side flaps 56, 57, 58, 59. These unheated areas are necessary to ensure a certain rigidity of the sheet that will allow its subsequent handling.

Heating may be effected by various means, for example by clamping the sheet between two heating pads having shapes adapted to effect heating according to the predetermined heating zones. The heating can also be carried out by infrared heating means or by blowing hot air.

The skilled person knows how to achieve such heating means. After completion of the heating, the first sheet is gripped with a piston 6 which has internal channels 61 which open through openings 63 on the lower face 62 and which allow to maintain by suction the first sheet 4. The face bottom 62 of the piston 6 has a dimension which is substantially equal to the dimension of the bottom of the bucket to be formed. With the aid of this piston 6, the first sheet 4 is pushed through a forming chimney 7, at least two opposite lower edges of which have pressure rollers 71 which can exert a lateral force so as to be able to clamp the sheet against the walls of the forming piston. These pressure rollers are mounted on spring means, such as coil springs or blades with adjustable springs 72 which adjust the pressure exerted by the springs on the sheet 4. This forming chimney 7 opens on a plate having a cell 9 whose side wall 90 has suction holes 91 which allow to press the side faces of a bucket against these walls. This cell is closed at its bottom by an ejector piston 92.

With the aid of these devices and during the shaping operation 3, a cup 8 is made by folding comprising lateral faces 81 which are constituted by the four lateral flaps of the sheet 4. These lateral edges comprise legs 82 which are sealed against lateral uprights 81. These sealed side tabs 82 correspond to tabs 53 which have been prepared on the first sheet which had been cut. The tabs 82 are sealed by heat-sealing taking advantage of the heat that results from the pre-heating done during the preheating operation O2.

The bucket 8 is received in the cell 9 and it is cleared from the forming stack 7 to be brought into a filling station to perform a filling operation O4 which consists of filling pasty products with a filling zone inside. of the bucket, so as to constitute a load 11, using for example an injection port 10.

This filling operation is well known to those skilled in the art. After filling of the bucket, it is brought into a position of establishment of a cover 13. This cover 13 is made of a second sheet of plastic material, one of whose faces is optionally covered with a heat-sealable lacquer which is cut into a shape slightly larger than that of the bottom of the bucket. This sheet is gripped by a piston 12 having channels 120 opening on its underside through openings 121 which allow to maintain by suction the second sheet against the underside of the piston. The piston passes the second sheet through a forming plate to form a lid having a concave shape having a bottom of rectangular shape corresponding to the bottom of the bucket, bordered by a small peripheral rim 14, intended to allow sealing in the cup and deposits the lid on the upper face of the pasty product load contained in the cup. This pause operation of the lid is marked O5 in the figures.

After pausing the lid on the upper face of the dough contained in the cup, the rim 14 of the lid 13 is sealed by heat-sealing against the upper edges 81 A of the side faces 81 of the cup 8. This heat-sealing is carried out at the using heating jaws 15 which laterally grip the upper portion 81A of the rim of the bucket and the flanges 14 of the cover against the handling piston 12.

Once this first sealing is carried out, in a last operation marked 07, the flanges 81 A are folded against the upper face of the cover 13 by means of skids 16 which extend laterally, then the flanges 81 A of the side faces 81 which extend beyond the rims 14 of the lid, are sealed against the upper face of the lid 13 by means of a heating pad 17.

This gives a part of pasty product such as a processed cheese or a fresh cheese or a fresh cheese packaged in a package 8 comprising side walls 81 which have tabs 82 sealed on the side faces 81 and whose edges 81 A are folded and sealed against the lid 13. On the upper face of the lid, one end of the easy opening ribbons 3 extends beyond the flanges 81A, which makes it easy to grasp and open the package easily. .

The process just described can be implemented using pasty packaging facilities such as processed cheeses that the skilled person knows how to achieve. In particular, the pause and lid sealing operations are known operations. The person skilled in the art knows how to produce machines that make it possible to mass-produce packages. pastes by providing for a succession of adapted posts and transfers of portions during filling of a post to the next post.

In the embodiment described, the package comprises easy opening ribbons, but packaging according to the invention may not include such ribbons or have different easy opening means.

Finally, the portions of packaged pasty product can have any form of polygonal type.

Claims

1.- Method for packaging a pasty product such as a processed cheese or a fresh cheese or a fresh cheese in an easy opening sealed packaging consisting of two thin sheets of plastic material, a first sheet (4) a cup (8) having a bottom (80) and side faces (81) and a second leaf forming a lid (13) sealingly sealed to the flanges (81A) of the bucket, wherein:

the first sheet (4) is cut in an appropriate contour;

- the first sheet (4) is folded to form a bucket (8) whose side faces (81) extend beyond the filling area of the bucket;

- Filling the filling area of the bucket with pasty product;

on the free surface of the pasty product (11) contained in the cup (8), the second cut sheet has dimensions at least equal to those of the bottom of the cup so as to form a lid (13), and

- the cover (13) is sealed on the side faces (81), characterized in that, before folding the first sheet (4), the sheet (4) is heated in zones (5) chosen to allow a thermoforming during folding.

2. A method according to claim 1, characterized in that the heating of the sheet (4) is effected by contact with at least one hot plate recessed in the parts to be saved or by infrared radiation or by blowing hot air.

3. A process according to claim 1 or claim 2, characterized in that, before forming the bucket (8), is fixed on the first sheet (4) at least one easy opening strip (3).

4. A process according to any one of claims 1 to 3, characterized in that the first sheet (4) comprises a heat-sealable lacquer on the face intended to be located inside the package and in that the first sheet (4) is cut so that, after forming the cup, at least one first side face (81) has a tab (82) whose inner face comes into contact with the external face of a second side face of the bucket and in that heat sealed the tab on the second side face.

5.- Method according to any one of claims 1 to 4, characterized in that to form the first sheet (4) by folding, or the capture with a piston (6) provided with suction holes (63), then the sheet (4) is passed through a forming shaft (7) of the bucket having at its base pressure rollers (71) with which the side faces (81) of the bucket are clamped so as to form the folds and possibly thermo-seal a tab (82) of a side face

(81) of the bucket against another side face (81) of the bucket.

6. A process according to any one of claims 1 to 5, characterized in that, after forming the bucket (8), the bucket (8) is transferred into a cell (9) having suction holes (91) at its periphery, and the side faces (81) of the bucket (8) are pressed against the side faces of the cell by suction and the suction is maintained during the filling of the bucket.

7. A process according to any one of claims 1 to 6, characterized in that to set up and seal the lid: - the second sheet is grasped with a piston (12) provided with holes suction (121);

- Using the piston (12), the second sheet is passed through a forming plate so as to give the cover (13) a concave shape with a small peripheral rim (14); - The lid is deposited in contact with the upper face of the product (11) contained in the bucket;

- Sealing the edges (14) of the cover on the side faces (81A) of the bucket (8) by clamping heating jaws (15) against the outer piston (12); and - the flanges (81 A) of the side walls (81) of the cup (8) are folded against the upper face of the lid (13) and sealed by heat-sealing with a heating pad (17).

8. A process according to any one of claims 1 to 7, characterized in that at least the first sheet (4) is polypropylene, optionally oriented, and has on one of its faces a thermo sealable lacquer layer.

9.- Installation for implementing the method according to any one of claims 1 to 7, characterized in that it comprises: - A preheating station before forming a cut sheet to be formed to form a bucket;

- a forming station of a bucket comprising a forming piston (6) and a forming chimney (7); - A cell (9) for receiving and transferring a bucket.

10.- Installation according to claim 9, characterized in that the piston

(6) of the forming station comprises holding means (61, 63), in particular by suction, a sheet against the piston, and in that the forming chimney

(7) comprises at its base lateral clamping means of a sheet being formed against the side faces of the piston.

11.- Installation according to claim 10, characterized in that the lateral clamping means arranged at the base of the chimney (7) forming consist of rollers (71) mounted on elastic means (72) adjustable.

12.- Installation according to any one of claims 9 to 11, characterized in that the receiving recess (9) has at its periphery suction means (91) adapted to press the side faces of a bucket against the lateral faces of the cell.

13.- Installation according to any one of claims 9 to 12, characterized in that it further comprises one or more of the following positions:

unwinding a plastic strip and cutting a first or second sheet,

- easy opening tapes,

- filling a bucket; - setting up a lid and sealing the lid using heated jaws,

- Folding and sealing the edges of the bucket.