Tools for forming a separation line in a package of food pots

Description

Domaine technique

[0001] The present disclosure relates to the field of equipment for separating packs of food product jars and forming pre-cut lines in such packs of food product jars. The present disclosure relates more specifically to tools of equipment for separating packs of food product and forming pre-cut lines. Technique antérieure

[0002] Food products such as dairy, liquid, creamy, pasty or foamy products in batches or packs are typically contained in a multi-housing container obtained by forming plastic material. After forming, the housings are filled with the food product and sealed with a lid. Subsequently, a grooving or pre-cutting is made to incise the lid and the plastic material to a certain depth, allowing separation by breaking the pack into a plurality of pots. Depending on the need, in certain areas, a complete cut can be made, for example to separate the packs.

[0003] In an effort to increase the recyclability rate of jars after use, there is a trend toward using Polyethylene Terephthalate (PET) to form packs. Recycling this plastic material is indeed common and well-managed.

[0004] However, in the case where the container is formed from PET, there is a need to adapt the grooving to obtain satisfactory break separation.

[0005] Document EP3766799 describes equipment for forming a pre-cut in a pack of food product pots comprising a first cutting tool configured to make a pre-cut groove from the top of the pack and a second cutting tool configured to make a pre-cut groove from the bottom of the pack. This equipment effectively makes it possible to facilitate the separation by folding and breaking of two food product pots for a range of plastics including in particular PET.

[0006] However, it has been found that when the force applied by one of the cutting tools is insufficient, the plastic is not pushed sufficiently against the other cutting tool, so that the penetration of the plastic is insufficient to obtain a satisfactory pre-cut. In addition, a significant force applied to the cutting tool can cause it to bend. In a case where the cutting tools are configured to pass through the entire plastic material (i.e., perform a total cut), this bending can lead to mechanical contact between the cutting tools, and therefore their deterioration.

[0007] There is therefore a need for cutting tools and equipment for forming a pre-cut and / or a full cut which do not have the above disadvantages. Résumé

[0008] A knife is provided for equipment for forming a pre-cut in a pack of food product pots, said pre-cut facilitating separation by breaking along a separation line between two food product pots, the knife comprising a cutting portion configured to make a pre-cut groove and / or a total cut along the separation line, said cutting portion extending along a first longitudinal axis, such that, seen in section perpendicular to the longitudinal axis, the cutting portion extends on either side of a transverse axis and the cutting portion comprises: on the one hand of the transverse axis (A): - a first portion extending between a first point forming the end of the cutting portion and a second point, the straight line connecting the first and second points forming with the transverse axis a first angle of between 20° and 40;- a second portion extending between the second point and a third point, the straight line connecting the second and third points forming with the transverse axis a second angle of between 15° and 25°; and on the other hand of the transverse axis: - a third portion extending between the first point and a fourth point, the fourth point being coincident with the transverse axis, - a fourth portion extending from the fourth point to a fifth point, the fifth point being symmetrical to the third point with respect to the transverse axis, the straight line connecting the fourth and fifth points forming with the transverse axis a third angle of between 15° and 25°.;

[0009] Such a knife shape allows sufficient force to be applied to the packs of pots to push the plastic against a counterblade of the equipment to form a pre-cut. The pre-cut grooves are suitable for separating the pots by breaking along the separation lines and are obtained in a repeatable manner.

[0010] In addition, such a knife shape limits the bending of the knife when a groove is made. The risk of damage to the knife, and in particular the risk of the knife coming into contact with the counterblade, is reduced.

[0011] The features set out in the following paragraphs may, optionally, be implemented independently of each other or in combination with each other.

[0012] The first portion may extend over a distance, measured along the direction of the transverse axis, between 0.02 mm and 0.2 mm. The first portion contributes to the mechanical strength of the knife when the knife attacks the plastic.

[0013] The third portion may extend over a distance, measured along the direction of the transverse axis, of between 0.2 mm and 0.8 mm. The third portion forms a flat face of the knife, contributing to the satisfactory cutting of the plastic. The third portion may face a counter-blade of the equipment, so that the depth of the grooves made may be increased until a total cut is obtained (i.e., passing through the entire thickness of the pots) without the knife and the counter-blade meeting.

[0014] A distance between the first point and the fifth point, measured along the direction of the transverse axis, can be between 1.4 mm and 2 mm. The height of the cutting part is then suitable for making pre-cut grooves and total cuts on a range of pot thicknesses.

[0015] The knife may further comprise a connecting portion extending from the cutting portion to a body of the knife, the connecting portion extending symmetrically on either side of the transverse axis from the third and fifth points at an opening angle of between 100° and 140°. The connecting portion makes it possible to stiffen the knife and thus reduce the risk of bending.

[0016] The knife may further comprise a cylindrical portion extending in the direction of the transverse axis. The cylindrical portion facilitates mounting of the knife in the equipment. The cylindrical portion may be identical regardless of the profile and shape of the cutting part, so that different knives may be mounted in the same equipment.

[0017] According to another aspect, there is provided a counter-blade for equipment for forming a pre-cut in a pack of food product pots, said pre-cut facilitating a separation by breaking along a separation line between two food product pots, the counter-blade comprising an active part configured to make a pre-cut groove and / or a total cut along the separation line, said counter-blade extending along a second longitudinal axis such that, seen in section perpendicular to the second longitudinal axis, the active part comprises: - an edge defining a flat face of the active part; - a first segment extending between a first point forming the end of the active part and a second point, the straight line connecting the first and second points forming with the edge a first angle of between 20° and 40°;- a second segment extending from the second point to a third point, the straight line connecting the second and third points forming with the edge a second angle between 15° and 25°;

[0018] Such a counterblade shape ensures sufficient penetration of the plastic when force is applied to the pots by a knife of the equipment to form a pre-cut. The pre-cut grooves are suitable for separating the pots by breaking along the separation lines and are obtained in a repeatable manner. In addition, such a counterblade shape limits the bending of the counterblade when a groove is made. The risk of damage, and in particular the risk of the counterblade coming into contact with the knife, is reduced.

[0019] The features set out in the following paragraphs may, optionally, be implemented independently of each other or in combination with each other.

[0020] The first segment can extend over a distance, measured along the direction of the edge, between 0.02 mm and 0.1 mm. The first segment contributes to the mechanical strength of the counterblade when the counterblade attacks the plastic.

[0021] The edge can extend over a distance between 0.02 mm and 0.1 mm. The edge forms a flat face of the counterblade, contributing to the satisfactory cutting of plastic. The edge can face a knife of the equipment, so that the depths of the grooves made can be increased until a complete cut is obtained without the knife and the counterblade meeting.

[0022] The edge may further comprise a body of substantially rectangular section, the second segment being connected to the body by a clearance extending from the third point. Thus, the counterblade is sufficiently rigid to withstand the forces applied to the counterblade when a groove or a full cut is made.

[0023] According to yet another aspect, there is provided equipment for forming a pre-cut in a pack of food product pots, said pre-cut facilitating separation by breaking along a separation line between two food product pots, the equipment comprising: - at least one knife, and - at least one counter-blade, the flat face of the counter-blade facing the third portion of the knife.

[0024] Such equipment ensures that the knife forces the pots against the counterblade to ensure a satisfactory pre-cut is achieved in a repeatable manner. In addition, the shape of the knife and counterblade limits their flexing. The risk of damage to the knife and counterblade, and in particular the risk of the knife coming into contact with the counterblade, is reduced.

[0025] The features set out in the following paragraphs may, optionally, be implemented independently of each other or in combination with each other.

[0026] The distance between the knife and the counterblade can be between 0.003 mm and 0.1 mm. This distance, also called undercut, increases the height of the grooves made in the plastic to achieve a full cut. Undercutting prevents mechanical contact between the knife and the counterblade during a full cut.

[0027] The equipment may include an upper support plate receiving the knife and a lower support plate receiving the counterblade, the pack of food product pots being configured to be received between the upper support plate and the lower support plate, the upper support plate and the lower support plate having a relative displacement perpendicular to the plane defined by the upper surface of the food product pots. The pre-cutting equipment is then formed as a press, and the penetration depths of the knives and counterblades into the plastic material of the pack can be controlled. Control of the penetration depths can be at least in part achieved through the spacing and relative displacement between the lower and upper support plates.

[0028] According to another aspect, there is proposed an installation for preparing packs of food product pots comprising: - a first piece of equipment configured to both carry out an operation of sealing a lid and carry out from below a localized cooling operation of the junction zones of the pots, and, arranged downstream of said first piece of equipment, - a second piece of equipment for forming a pre-cut. Brève description des dessins

[0029] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analyzing the attached drawings, in which: Fig. 1 [ Fig. 1 ] schematically illustrates a top view of a pack of food product jars according to one embodiment. Fig. 2 [ Fig. 2 ] schematically illustrates a side view of the pack of food product jars of the figure 1 according to one embodiment. Fig. 3 [ Fig. 3 ] schematically illustrates a front view of equipment for forming pre-cut lines at a separation zone between two food product pots according to one embodiment. Fig. 4 [ Fig. 4 ] schematically illustrates a cross-sectional view of the equipment of the figure 3 . Fig. 5 [ Fig. 5 ] illustrates a detail of the figure 4 . Fig. 6 [ Fig. 6 ] schematically illustrates a side view of a knife that can be implemented in the equipment of the figure 3 . Fig. 7 [ Fig. 7 ] illustrates a detail of the figure 6 . Fig. 8 [ Fig. 8 ] illustrates a detail of the figure 7 . Fig. 9 [ Fig. 9 ] schematically illustrates a side view of a counterblade that can be implemented in the equipment of the figure 3 . Fig. 10 [ Fig. 10 ] illustrates a detail of the figure 9 . Description des modes de réalisation

[0030] THE figures 1 et 2 represent a pack of 10 jars of 12 food products. The food product can be a classic food or a functional food. The food product can be any type of dairy food. The product can be liquid, creamy, pasty or foamy.

[0031] The term 'pack' should be understood as a set forming a sales batch, this set comprising several individual consumption units (each unit being called a 'pot' or 'cup' here). Each individual consumption unit forms a portion of food for an individual who, at the end of consumption, throws the empty pot, i.e. the primary packaging, into a bin or recycling system.

[0032] In the example illustrated, a pack 10 of six pots 12 is shown. However, it should be understood that the number of pots 12 can be any, that is to say that the pack 10 can include 2 pots, 4 pots, 6 pots, 8 pots, or even 9 pots, 10 pots, and even 12 pots.

[0033] In the illustrated example, a reference plane PR is defined at the level of the upper surface of the pots 12, the reference plane PR comprising a longitudinal direction denoted L and a transverse direction denoted T. A vertical direction denoted Z is also defined, substantially normal to the reference plane PR.

[0034] The pots 12 of food product, seen in cross-section (perpendicular to the reference plane PR), may have a slightly conical shape like that illustrated in the figure 2 . In a variant, there is no taper and the sides of the pots 12 can be strictly parallel to the vertical (i.e. parallel to the vertical axis Z). The pots 12 of food product can also be pots 12 with a convex side wall, not demouldable by a simple mold.

[0035] The pots 12 are formed from a multi-housing container. The multi-housing container may be formed from plastic. The material used to form the multi-housing container may be polyethylene terephthalate (PET). It should be noted that either translucent PET or opaque PET may be used. Alternatively, the material used to form the multi-housing container may be polypropylene (PP). The plastic may be blown or injected into a mold to thereby obtain the multi-housing container.

[0036] The thickness denoted e2 of the plastic material of the container may be substantially uniform over the entire multi-housing container. The thickness e2 is typically between 0.6 mm and 2 mm, at least at the junction zones between the pots 12.

[0037] The pots 12 are, following their formation, filled with food product and sealed by a cover sheet 14. The cover sheet 14 extends over the upper surface of the pots 12, i.e. parallel to the reference plane PR. The cover sheet 14 has a thickness denoted e1 typically between 0.03 mm and 0.1 mm. The material constituting the cover sheet 14 can be formed by a multi-layer assembly, with a very thin layer of aluminum foil and a decorative and / or labeling layer.

[0038] Provision is made to provide separation lines 16 on all sides where a connection connects one pot 12 to a neighboring pot 12. These separation lines 16 are fusible lines that break when one pot 12 is tilted relative to the other. The separation lines 16 make it possible to separate each of the pots 12 for individual consumption. Provision is also made to form star-shaped holes 18 at the corners between four pots 12. These holes 18 further facilitate the separation of the pots 12.

[0039] A pre-cutting equipment 20 is used to form the parting lines 16 and the holes 18. The pre-cutting equipment 20 is formed like a press. The pre-cutting equipment 20 essentially comprises an upper support plate 22 and a lower support plate 24. As seen in the figure 3 , the packs 10 are received between the lower and upper support plates 22, 24.

[0040] The upper support plate 22 and the lower support plate 24 have a relative movement in the direction of the vertical axis Z, i.e. the direction normal to the reference plane PR when a pack 10 of pots 12 is placed in the equipment 20. Here, the upper support plate 22 can be moved along the vertical axis Z while the lower support plate 24 is fixed. Conversely, the lower support plate 24 could be moved along the vertical axis Z, or both the lower and upper plates 22, 24 could be movable along the vertical axis Z.

[0041] Here, the upper support plate 22 receives one or more knives 26. When a pack 10 of pots 12 is arranged between the lower and upper support plates 22, 24, the knives 26 extend above the separation lines 16. Thus, the knives 26 are adapted to form a pre-cutting groove from above along the separation line 16.

[0042] It is noted that the upper support plate 22 can also receive one or more star-shaped punches. When a pack 10 of pots 12 is arranged between the support plates 22, 24, the star-shaped punches are located at the holes 18. The punches can then be used to cut the star-shaped holes 18.

[0043] The lower support plate 24 receives at least one counter-blade 28. When a pack 10 of pots 12 is arranged between the lower and upper support plates 22, 24, the counter-blades 28 extend below the separation lines 16. Thus, the counter-blades 28 are adapted to form a pre-cutting groove from below along the separation line 16.

[0044] The number of knives 26 and counter-blades 28 can correspond to the number of separation lines 16 to be produced, so that a single movement between the upper support plate and the lower support plate 22, 24 makes it possible to form all the separation lines 16 in a pack 10. It is also possible to provide enough knives 26 and counter-blades 28 to process several packs 10 at the same time. The productivity of the equipment 20 is increased.

[0045] As more visible at the figure 5 , in particular thanks to the precision of the press, the penetration depths of the knives 26 and the counter-blades 28 in the plastic material of the pack 10 are controlled. The control of the penetration depths can be ensured in part or in full thanks to the spacing and the relative movement between the lower and upper support plates 22, 24. In this case, the spacing between the two support plates 22, 24 is fixed in the working position at the dimension e7, that is to say the sum of the thicknesses e1 of the cover sheet 14 and the thickness e2 of the plastic material at the junction between the pots 12.

[0046] As illustrated in the figure 5 , each knife 26 makes a groove over a height D3 from the top of the pack 10, and each counter-blade 28 makes a groove over a height D4 from the bottom of the pack 10.

[0047] The height D3 of the groove made by the knife 26 is between 10% and 80% of the thickness e2 of the plastic material, preferably between 20% and 60% of the thickness e2 of the plastic material. The knife 26 also makes it possible to groove the entire thickness e1 of the lidding sheet 14. The height D4 of the groove made by the counter-blade 28 is between 25% and 50% of the thickness e2 of the plastic material, preferably between 30% and 40%. In this case, the height D3 of the groove made by the knife 26 is greater than the height D4 of the groove made by the counter-blade 28. Such grooves ensure good separation of the pots 12 along the pre-cut lines 16.

[0048] A remaining distance D5 is defined which is not incised, neither by the knife 26, nor by the counter-blade 28. This remaining distance D5 is sufficient so that the connecting zones between the pots 12 allow the pack 10 of pots 12 to be lifted only by one or two pots 12 without holding the other pots 12. For example, the remaining distance D5 is between 20% and 60% of the thickness e2 of the plastic material. Preferably, the remaining distance D5 is between 25% and 45% of the plastic material.

[0049] Furthermore, a distance D6 separating the knife 26 and the counter-blade 28, measured in the direction normal to the vertical axis Z, is between 0.003 and 0.1 mm. Such a distance D6, also called a pinching distance, makes it possible to increase the height of the grooves made in the plastic to perform a total cut, i.e. to cross the entire side e7 (the sum of the thicknesses e1 of the lidding sheet 14 and the thickness e2 of the plastic material at the junction between the pots 12). Indeed, the pinching distance makes it possible to avoid mechanical contact between the knife 26 and the counter-blade 28 during a total cut. The total cut can, for example, make it possible to perform a separation between several packs 10 of pots 12 of food product.

[0050] A knife 26 is then described. As illustrated in figure 6 , the knife 26 is here received in the upper plate 22 of the equipment 20, to be moved in the direction of the vertical axis Z and to carry out a pre-cut from above.

[0051] The knife 26 essentially comprises a cutting part 32 intended to come into contact with the plastic, a body 30 ensuring the rigidity of the knife 26, and a cylindrical part 34 intended to allow the knife 26 to be mounted in the upper support plate 22 of the equipment 20.

[0052] The cutting portion 32 extends along a longitudinal axis X. When the knife 26 is received in the upper support plate 22, the cutting portion 32 extends along a separation line 16. The cutting portion 32 is intended to incise the packs 10 of pots 12 to form the separation lines 16.

[0053] As visible on the figures 7 And 8, seen from the side, the cutting part 32 extends on either side of a transverse axis A of the knife 26, from a free end of the cutting part 32 towards a connecting part 44, connecting the cutting part 32 to the body 30.

[0054] On the one hand of the transverse axis A, intended to be opposite the counter-blade 28 when the knife 26 is housed in the upper support plate 22, the cutting part 32 defines a first portion 36, a second portion 38 and a third portion 40.

[0055] The first portion 36 extends from a first point P1 forming the end of the cutting part 32 to a second point P2. A straight line connecting the first and second points P1, P2 forms with the transverse axis A a first angle A1 of between 20° and 40°. The first portion 36 extends over a distance L1, measured in the direction of the transverse axis A, of between 0.02 mm and 0.2 mm. The first portion 36 contributes to the mechanical strength of the knife 26 at the time of attack of the plastic by the knife 26.

[0056] The second portion 38 extends from the second point P2 to a third point P3. A straight line connecting the second and third points P2, P3 forms with the transverse axis A a second angle A2 of between 15° and 25°. The second angle A2 makes it possible to reduce the penetration forces perceived by the cutting part 32. In addition, the second angle A2 helps to exert a force on the lower support plate 24 to push the plastic against the counter-blade 28. The grooves from below, made by the counter-blade 28, are then improved.

[0057] On the other side of the transverse axis A, that is to say on the side intended to face the counter-blade 28 when the knife 26 is received in the upper support plate 22, the cutting part 32 comprises a third portion 40 and a fourth portion 42.

[0058] The third portion 40 extends from the first point P1 forming the end of the knife 26 and a fourth point P4 coinciding with the transverse axis A. The third portion 40 forms a flat face of the cutting part 32. The third portion 40 extends over a distance L2, measured in the direction of the transverse axis A, of between 0.2 and 0.8 mm.

[0059] The fourth portion 42 extends from the fourth point P4 to a fifth point P5. A straight line connecting the fourth and fifth points P4, P5 forms with the transverse axis A a third angle A3 of between 15° and 25°. The fourth portion 42 makes it possible to balance the cutting force on either side of the transverse axis A, so as to reduce the bending caused by the second angle A2 of the second portion 36. The fourth portion 42 also helps to push the plastic onto the counter-blade 28, to improve the groove from below, in particular by ensuring that the counter-blade 28 penetrates the plastic over the incise height D4 from below.

[0060] The third and fifth points P3, P5 are symmetrical with respect to the transverse axis A. The connecting portion 44 extends on either side of the transverse axis A from the points P3 and P5 to connect the cutting portion 32 to the body 30 of the knife 26. A distance L3 between the first point P1 forming the end of the knife 26 and the third and fifth points P3, P5, measured in the direction of the transverse axis A, is between 1.4 and 2 mm. In other words, the height of the cutting portion 32 is between 1.4 and 2 mm.

[0061] The connecting part 44 extends symmetrically on either side of the transverse axis A at an opening angle A4 of between 100° and 140°. The opening angle A4 makes it possible to stiffen the knife 26 to prevent bending of the knife 26.

[0062] Back on the figure 6 , the body 30 extends along the longitudinal axis X. The body 30 has a polygonal section, to give the knife 26 sufficient rigidity to withstand the forces applied to the knife 26 when a pre-cut is carried out. The section of the body 30 is further adapted to be received in a housing or slide of the upper plate 22, in particular to ensure the correct orientation of the knife 26 in the upper plate 22. The cutting part 32 may project from the housing or slide depending on the height of the groove to be made.

[0063] The cylindrical portion 34 extends from the body 30 in the direction of the transverse axis A. The cylindrical portion 34 extends on one side of the body 30 opposite the cutting part 32. The axis of revolution of the cylindrical portion 34 corresponds to the transverse axis A. The cylindrical portion 34 can be received in a cylindrical housing formed in the upper plate 22 of the equipment 20. The cylindrical portion 34 can be identical regardless of the profile and shape of the cutting part 32, so that different knives 26 can be housed in the same cylindrical housing of the upper plate 22.

[0064] A threaded hole 50 is here formed in the cylindrical portion 34. The threaded hole 50 extends along the axis of revolution A of the cylindrical portion 34, from an upper face of the cylindrical portion 34 towards the cutting part 32. The threaded hole 50 is adapted to receive a retaining screw of the equipment 20. The mounting of the cutting tool 30 by the retaining screw allows precise adjustment of the position of the knife 26 in the upper plate 22. Indeed, it is possible to finely adjust the incision height of the knife 26, by inserting the retaining screw more or less into the threaded hole 50.

[0065] Furthermore, the cylindrical portion 34 here comprises a cylindrical groove 55, with an axis equal to the axis of revolution A of the cylindrical portion 34. The cylindrical groove 55 ensures good propagation of grease around the cylindrical portion 34, to smooth the relative movement between the cutting tool 30 and the upper support plate 22.

[0066] A counterblade 28 is described below. The counterblade 28 is here received in the lower support plate 24 of the equipment 20 to make a pre-cutting groove from below. In this case, the force applied by the knife 26 forces the plastic onto the counterblade 28. Thanks to the shape of the cutting part 32 of the knife 26 described below, the plastic is pushed sufficiently onto the counterblade 28 to make a satisfactory and repeatable groove from below.

[0067] The counter blade 28 extends along a second longitudinal axis Y. When the counter blade 28 is received in the lower support plate 24, the counter blade 28 extends along a parting line 16.

[0068] The counter-blade 28 comprises an active part 54 intended to incise the plastic material, and a body 52 intended to be received in the lower plate 24.

[0069] Seen from the side, as shown in the figure 10, the active part 54 comprises an edge 56. The edge forms a flat face of the active part 54. The flat face is intended to face the knife 26 when the counter-blade 28 is received in the lower support plate 24.

[0070] The active part 54 also defines a first segment 58. The first segment 58 extends from a first point P11 of the active part 54 forming the free end of the active part 54 and a second point P12. A straight line connecting the first and second points P11, P12 form, with the edge 56, a first angle A11 of between 20° and 40°. The first segment 58 extends over a distance L11, measured in the direction of the edge 56, of between 0.02 and 0.2 mm. The first segment 58 contributes to the mechanical strength of the counter-blade 28 at the time of attack of the plastic by the counter-blade 28.

[0071] The active part 54 further defines a second segment 60. The second segment 60 extends from the second point P12 to a third point P13, forming with the edge 56 a second angle A12 of between 15° and 25°. The second segment 60 contributes to reducing the penetration forces perceived by the active part 54, and therefore to reducing the bending.

[0072] A clearance 62 extends from the third point P13 to connect the second segment 60 to the body 52 of the counter-blade 28. The edge 56 extends in continuity with one side of the body 52.

[0073] The body 52 here has a substantially rectangular section. The body 52 can be received in a housing or slide of the lower plate 24 to ensure the correct orientation of the counter-blade 28 in the lower plate 24. The active part 54 can project from the housing or slide depending on the height of the groove to be made.

[0074] The invention is not limited to the examples of embodiments described with reference to the figures and other embodiments will become clear to those skilled in the art.

[0075] For example, the lower support plate 24 could receive one or more knives 26, and the upper support plate 22 could receive one or more counter-blades 28. This embodiment appears interesting when the lower support plate 24 is movable in the direction of the vertical axis Z.

[0076] Furthermore, the equipment 20 described below may be part of an installation. The installation may comprise a first equipment configured to carry out a step of sealing the lid 14 on the pack 10 of pots 12 and a step of localized cooling of the junction zone between the pots 12 and a pre-cutting equipment 20 as described above.

[0077] In this case, the first equipment comprises sealing electrodes adapted to come into contact with the upper face of the pack 10, and a contact counterpart adapted to come into contact from below the junction zone between the pots 12. The contact counterpart is preferably thermo-regulated, for example by the circulation of an iced water fluid or another low-temperature fluid in the counterpart. The sealing electrodes and the cooling counterpart sandwich the junction zone coated with the lid. It is thus possible to guarantee good pressure by the cooling counterpart and thus a good conduction heat transfer coefficient in the contact zone. Since the cooling is localized, it is selective, it does not significantly affect the food product contained in the pots 12.

Claims

1. A knife (26) for an equipment (20) for forming a precut in a pack (10) of food cups (12), said precut facilitating separation by breaking along a separation line (16) between two food cups (12), wherein the knife (26) comprises a cutting part (32) configured for making a precut groove and / or a full cut along the separation line (16), wherein said cutting part (32) extends along a first longitudinal axis (X), such that, seen in section perpendicular to the longitudinal axis (X), characterised in that the cutting part (32) extends on either side the transverse axis (A) and in that the cutting part (32) comprises: on one side of the transverse axis (A): - a first portion (36) extending between a first point (P1) forming the end of the cutting portion (32) and a second point (P2), wherein the straight line connecting the first and second points (P1, P2) forms a first angle (A1) with the transverse axis (A) comprised between 20° and 40°; - a second portion (38) extending between the second point (P2) and a third point (P3), wherein the straight line connecting the second and third points (P2, P3) forms a second angle (A2) with the transverse axis (A) comprised between 15° and 25°; and on the other side of the transverse axis (A): - a third portion (40) extending between the first point (P1) and a fourth point (P4), wherein the fourth point (P4) coincides with the transverse axis (A); - a fourth portion (42) extending from the fourth point (P4) to a fifth point (P5), wherein the fifth point (P5) is symmetric to the third point (P3) about the transverse axis (A), and wherein the straight line connecting the fourth and fifth points (P4, P5) forms a third angle (A3) with the transverse axis (A) comprised between 15° and 25°.

2. The knife (26) according to claim 1, wherein the first portion (36) extends over a distance (L1), measured along the direction of the transverse axis (A), comprised between 0.02 mm and 0.2 mm.

3. The knife (26) according to claim 1 or 2, wherein the third portion (40) extends over a distance (L2), measured along the direction of the transverse axis (A), comprised between 0.2 mm and 0.8 mm.

4. The knife (26) according to any one of the preceding claims, wherein a distance (L3) between the first point (P1) and the fifth point (P5), measured along the direction of the transverse axis (A), is comprised between 1.4 mm and 2 mm.

5. The knife (26) according to any one of the preceding claims, further comprising a connecting part (44) extending from the cutting part (32) to a body (30) of the knife (26), wherein the connecting part (44) extends symmetrically on either side of the transverse axis (A) from the third and fifth points (P3, P5) following an angle of opening (A4) comprised between 100° and 140°..

6. The knife (26) according to any one of the preceding claims, further comprising a cylindrical portion (34) extending along the direction of the transverse axis (A).

7. A counter-knife (28) for an equipment for forming a precut in a pack (10) of food cups (12), wherein the counter-knife (28) is adapted to cooperate with a knife (26) according to any one of claims 1 to 6, said precut facilitating separation by breaking along a separation line (16) between two food cups (12), wherein the counter-knife (28) comprises an active part (54) configured for making a precut groove and / or a full cut along the separation line (16), wherein said counter-knife (28) extends along a second longitudinal axis (Y) such that, seen in section perpendicular to the longitudinal axis (Y), characterised in that the active part (54) comprises: - an edge (56) defining a flat surface of the active part (54); - a first segment (58) extending between a first point (P11) forming the end of the active part (54) and a second point (P12), wherein the straight line connecting the first and second points (P11, P12) forms a first angle (A11) with the edge (56) comprised between 20° and 40°; - a second segment (60) extending between the second point (P12) and a third point (P13), wherein the straight line connecting the second and third points (P12, P13) forms a second angle (A12) with the edge (56) comprised between 15° and 25°.

8. The counter-knife (28) according to claim 7, wherein the first segment (58) extends over a distance (L11), measured along the direction of the edge (56), comprised between 0.02 mm and 0.1 mm.

9. The counter-knife (28) according to one of claims 7 or 8, wherein the edge (56) extends over a distance (L12) comprised between 0.02 mm and 0.1 mm..

10. The counter-knife (28) according to one of claims 7 to 9, further comprising a body (52) of substantially rectangular section, wherein the second segment (60) is connected to the body (52) by a chamfer (62) extending from the third point (P13).

11. Equipment (20) for making a precut in a pack (10) of food cups (12), wherein said precut facilitates separation by breaking along a separation line (16) between two food cups (12), wherein the equipment (20) comprises: - at least one knife (26) according to one of claims 1 to 6, and - at least one counter-knife (28) according to any one of claims 7 to 10, wherein a flat surface of the counter-knife (28) faces the third portion (40) of the knife (26).

12. Equipment (20) according to claim 11, wherein a distance (D6) between the knife (26) and the counter-knife (28) is between 0.003 mm and 0.1 mm.

13. The equipment (20) according to one of claims 11 or 12, comprising an upper support plate (22) receiving the knife (26) and a lower support plate (24) receiving the counter-knife (28), wherein the pack (10) of food cups (12) is configured to be received between the upper support plate (22) and the lower support plate (24), wherein the upper support plate (22) and the lower support plate (24) have a relative displacement perpendicular to the plane (RP) defined by the upper surface of the food product cups (12).

14. A facility for preparing packs (10) of food cups (12) comprising: - a first equipment configured for simultaneously making a sealing operation of a cover (14) and a localized cooling operation of the junction zones of the cups (12) from below; and, arranged downstream from said first equipment, - a second equipment (20) for making a precut, where said second equipment (20) conforms to any one of claims 11 to 13.