ES2410560T3 - Container, method and apparatus for packaging products - Google Patents

Abstract

Method comprising moving along a displacement direction (F) thermoformable laminar material (100), deforming said laminar material (100) to make at least one cavity (51) of a container (50) provided with means (52, 53 , 54), fill said cavity (51) with a product (80), close said cavity (51) with an additional laminar material (200), after making said closure, deform a desired part (52) of said means ( 52, 53, 54) of wall to vary the internal volume of said cavity (51), wherein said deformation comprises bending said desired part (52) of said wall means (52, 53, 54) from an initial configuration (E ), in which said part (52) is curved out of said cavity (51), to a final configuration (G), in which said part (52) is curved inwards of said cavity (51), in which said closure comprises superimposing said additional sheet material (200) on said sheet material (100) and joining said sheet materials (100, 200) in an edge portion (55) of said cavity (51), said method comprising, after said joining, cutting said at least one cavity (51) of said container (50) separating the cavity (51) from said sheet material (100) and said additional sheet material (200), wherein said cutting comprises cutting said sheet material (100) and said additional sheet material (200) along said edge portion (55) of said at least a container (50), said method being characterized by the fact that it comprises, after said cutting, rotating said at least one container (50) to arrange said desired part (52) of said wall means (52, 53, 54) for its free deformation from said initial configuration (E) to said final configuration (G).

Description

Container, method and apparatus for packaging products

The present invention relates to containers, methods and apparatus for packaging products, specifically, it relates to an apparatus and method for thermoforming, hot filling with a product and sealing containers obtained from sheet material by a process of hot deformation.

Thermoformed containers for products are known, for example, for food products, comprising a housing or cavity in which a product is disposed and a sheet or film that is connected along an upper peripheral edge of the housing, by welding, to close the container tightly.

In the packaging of food products that are not liquid, fluid or semi-solid, for example, drinks, juices and the like, to ensure hygiene and aseptic properties of the process, in the case of cold filling of the containers with the product, it is necessary carry out a preventive sterilization of the material to be thermoformed and / or of the thermoformed container and of the closing film before the aforementioned filling. For this purpose, the materials should be suitable for a sterilization treatment, which is generally carried out using liquid hydrogen peroxide as a sterilizing agent.

However, these sterilization processes are complex and expensive to obtain and incorporate into the production of the container and the filling process. In addition, remains of sterilizing agent remain in the sterilized materials that can determine variations in the appearance and surface finish of the containers.

Packaging processes are known in which a high degree of hygiene and aseptic properties are ensured by hot filling the containers with the product to be packaged. The product to be packaged is sterilized preventively at an elevated temperature, typically 70-80 ° C, and is maintained at this temperature even during the filling of the containers, which are then sealed.

In fact, the high temperature of the product makes it possible to purify the container, extract air from the container (which is empty when cooling has occurred) and transmit stability to the product, deactivating enzymes and microorganisms.

However, to achieve hot filling of a food product, it is necessary to use suitable rigid containers, which are capable of withstanding thermal change and subsequent mechanical stresses.

In the case of containers obtained by thermoforming of laminar material made of plastic, it is necessary to use a material that has a suitable thermal resistance and a thickness large enough to avoid that, during the cooling stage, the container is deformed or even imploded due to the vacuum that is created inside the container. However, such materials are very expensive.

Another drawback of these containers is the fact that the thermoforming process for thermoforming these sheet materials is more complex and expensive.

US 2736656 describes a method for manufacturing and filling food containers in individual rations. A strip of thermoplastic material is subjected to the action of heat, pressure and forming dies suitable for forming a succession of vessels with side walls, bottom walls and an edge of non-deformed strip material. The glasses are filled with a product and a cover of elastic plastic material is sealed in the edge strip that surrounds the individual glasses. The glass containers formed in this way are cut and separated from the strip and are ready for use. The cover and the bottom wall of the vessel are deformable to allow air to contract inside the vessel (i.e. when the hot fill product cools) or to allow air expansion inside the vessel (i.e. when the outside air pressure decreases).

WO 93/24391 describes a container comprising a side wall, a base and sealing means of the container. The base includes a support ring, the container being adapted to rest thereon, and a diaphragm part extending from the inner edge of the support ring, thus forming a central part of the base of the container. The diaphragm part is adapted to axially deform by bending in or out, preferably, towards the side wall, in order to adapt to pressure changes in the container, the part of the diaphragm being adjacent to the inner edge of the support ring and which extends from it substantially continuous.

An objective of the present invention is to improve the apparatus and methods of producing containers by forming known sheet material.

Another objective is to make known an apparatus and a method for forming, hot filling and closing containers obtained from any laminar material for food use and which is suitable for thermoforming.

Another objective is to improve known containers, especially to improve the mechanical strength of

containers and in reducing the manufacturing costs of the containers.

Another additional objective is to produce containers that are suitable for hot filling and that ensure a high degree of protection of the contained product. In a first aspect of the invention, a method according to claim 1 is disclosed. In a second aspect of the invention, an apparatus according to claim 3 is disclosed. It is possible to improve the understanding and implementation of the invention by referring to the attached drawings,

which show some embodiments thereof as a non-limiting example, and in which: Figure 1A is a schematic front view of an apparatus for producing containers according to the invention; Figure 1B is a schematic perspective view of the apparatus of Figure 1A; Figure 2 is a schematic perspective view of a thermoformable sheet material subjected to a plurality

of functional steps of the method for producing containers of the invention;

Figures 3A, 3B are, respectively, front and perspective views of a container obtained by thermoforming of the sheet material of Figure 2; Figure 4 is a section according to plane IV-IV of Figure 2A, in which the container is filled with a product; Figures 5A, 5B are sections of the container of Figure 4 closed by an additional sheet material in a manner

partial and complete, respectively;

Figure 6 is an enlarged view of a detail of the container of Figure 5, showing wall portions of said container; Figures 7A, 7B are, respectively, front and perspective views of the closed container of Figure 6

flipped and with a bottom wall facing up, in an initial outward curved configuration; Figure 8 is a section according to plane VIII-VIII of Figure 7A; Figure 9 is a section of the container of Figure 7A, in which the bottom wall is in a configuration

curved inward end;

Figure 10 is an enlarged view of a detail of the container of Figure 9 showing wall portions of said container; Figure 11 is a version of the container of Figure 10. Referring to Figures 1A and 1B, an apparatus 1 is shown to produce and then fill with a

product 80 containers 50 obtained by thermoforming a sheet material 100, for example, material made of

plastic. The sheet material 100, unwound from a coil 101, travels, for example, in an indexed manner, by means 19 of displacement 19, along a direction F of displacement, through a plurality of functional stations indicated below:

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a heating station 7 in which heating means 8 heat the sheet material 100 to a temperature close to the softening temperature;

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a forming station 2 in which forming means 3 deform parts of the sheet material 100 defining cavities 51;

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a filling station 4 in which the cavities 51 receive a product 80 to be packaged;

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a closing station 5 in which an additional sheet material 200 is superimposed on said sheet material 100 and fixed thereto to close the cavities 51;

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a cutting station 11 in which cutting means 12 separate filled and closed containers 50 from the formed sheet material 100; Y

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a dump station 13 in which said containers 50 rotate 180 ° to have a respective bottom wall 52 facing up.

The forming means 3 may comprise mechanical forming means, such as stretching or male tools and / or pneumatic forming means, such as air dispensing nozzles

compressed.

The forming means 3 make a plurality of cavities 51 arranged in a sheet material 100

or more rows that are substantially orthogonal with respect to the direction F of travel.

Specifically, the forming means 3 are configured to make a cavity 51, for example, in the form of a vessel, provided with wall means comprising a bottom wall 52, a side wall 53 and a connection wall 54.

The bottom wall 52 has a shape that is substantially externally convex in a direction opposite to that of the sheet material 100, in an initial outwardly curved configuration E. The bottom wall 52 forms, for example, a cover surface, with a double curve.

The bottom wall 52 is connected to the side wall 53 of said cavity 51 by the connection wall 54, with a substantially annular shape.

For example, the side wall 53 forms a cylindrical or conical surface.

The connecting wall 54 comprises a first part 54a connected to the side wall 53 and a second part 54b that forms a bearing surface arranged in a plane A that is substantially parallel with respect to the sheet material 100 and that is connected to a peripheral part 52a from the bottom wall 52.

The bottom wall 52 is shaped to form a deformable part of said wall means.

For this purpose, the lower wall 52 and the connecting wall 54 have a thickness less than that of the side wall 53 to allow said lower wall 52 to elastically deform and pass from the initial E-curved configuration to a G-curved configuration towards inside, as explained in detail below in the description.

The reduced thickness of the bottom wall 52 and the connection wall 54 is obtained by stretching the material by means of males of the forming means 3.

In the filling station 4, the cavities 51 are filled with a hot product 80 arranged to a predetermined level (Figure 4).

Introduction means 9 are arranged in the closing station 5 to extend said additional sheet material 200 and superimpose the additional sheet material 200 on the sheet 100 in order to close the cavities 51 mentioned above. For example, the additional sheet material 200 is an aluminum or plastic connection film unwound from an additional coil 201.

The closing station 5 further comprises welding means 10 that perform a welding, for example, a "removable" welding, between the sheet material 100 and the additional sheet material 200. More precisely, the welding means 10 perform a weld on an edge portion 55 of each cavity 51, said edge portion 55 having a substantially annular shape and a substantially constant width. Welding allows the cavity 51 to be closed tightly, which thus encloses a defined quantity of disposed product 80 and an initial volume 81 of air at the same temperature as the product (Figure 5B).

In the cutting station 11, the cutting means 12 make a shaped cut and separate the thermoformed, filled and closed containers 50 from the sheet material 100 and the additional sheet material 200. The excess material 103 of the cut is discharged out of the apparatus.

The cutting means 12, which are of known type and have not been shown in detail, can be hot-type die cutting, male-die or longitudinal and transverse blades.

The cutting means 12 may be configured to obtain from the sheet material 100 a plurality of separate and distinct containers 50. Therefore, each container 50 obtained has an edge portion 55 in which a respective cover 56 obtained by cutting said additional sheet material 200 is welded. The edge portion 55 forms a protruding annular edge by which it is possible to hold and support the container 50 during its movement.

In an embodiment not shown, the cutting means 12 are arranged to separate from the sheet 100 a row of containers 50 joined together by connecting strips by the edge portions 55.

Therefore, the obtained separate containers 50 are displaced through a turning station 13 in which they are turned to rest on the respective edge portions 55 and be arranged with the bottom walls 52 facing up.

The containers 50 are kept in this turned position to allow the product 80 and the air contained in the containers 50 to cool. Following this cooling, the air in the cavity 51 reduces its volume, causing the container 50 to deform, in the specific case, causing deformation of the lower wall 52, which bends inwards in a controlled manner, passing from the configuration E curved out initial to configuration G curved in final.

This localized and partial deformation of the container 50 is possible thanks to the lid form of the lower wall 52 and to the connecting wall 54 with a suitable shape, and thanks to the reduced thickness of said walls, which have an elasticity and flexibility that they are superior to those of the side wall 53.

In this way, to produce the container 50 that will be hot filled with a product 80, it is possible to use any thermoformable sheet material suitable for food use and temperature resistant of the disposed product, however using thicknesses that would cause deformation or breakage of the known containers.

In the final configuration G, each container 50 contains, in addition to the defined quantity of disposed product 80,

10 a residual volume 81 'of air at room temperature. In this configuration, the second part 54b of the connecting wall 54 acts as a stable bearing surface of the container 50.

Referring to Figure 11, an embodiment of the container 50 'is shown which differs from the container described above by the fact that the bottom wall 52', except for the peripheral part 52a ', has a thickness that is substantially equal to that of the side wall 53 ', and is substantially lid-shaped.

15 On the other hand, the thickness of the peripheral part 52a ’and the connection wall 54’ is lower.

The flexibility of the lower wall 52 'makes it possible to ensure the deformation of the lower wall 52' from the initial configuration E to the final configuration G. The peripheral part 52a 'and the wall 54' connecting with the respective parts 54a ', 54b' they act as an elastic joint to facilitate deformation of the bottom wall 52 '.

In a further embodiment of the container, not shown in the figures, the bottom wall is substantially flat,

20 while the side wall has a substantially annular part that is externally convex, that is, bent outwardly, which has a reduced thickness. This part is connected to the side wall to be able to deform in a controlled manner to a concave configuration during cooling of the hot product disposed in the container in order to compensate for the reduction in the volume of air contained in the container.

Claims (5)

one.

 A method comprising displacing a thermoformable sheet material (100) along a direction (F) of movement, deforming said sheet material (100) to make at least one cavity (51) of a container (50) provided with means (52, 53, 54) of wall, filling said cavity (51) with a product (80), closing said cavity (51) with an additional laminar material (200), after making said closure, deforming a desired part (52) of said wall means (52, 53, 54) for varying the internal volume of said cavity (51), wherein said deformation comprises bending said desired portion (52) of said wall means (52, 53, 54) of a configuration initial (E), wherein said part (52) is curved out of said cavity (51), to a final configuration (G), in which said part (52) is curved into said cavity (51) , wherein said closure comprises superimposing said additional sheet material (200) on said sheet material (100) and joining said mater laminar dials (100, 200) on an edge part (55) of said cavity (51), said method comprising, after said joining, cutting said at least one cavity (51) of said container (50) by separating the cavity ( 51) of said sheet material (100) and said additional sheet material (200), wherein said cut comprises cutting said sheet material (100) and said additional sheet material (200) along said part (55) of edge of said at least one container (50), said method being characterized by the fact that it comprises, after said cutting, rotating said at least one container (50) to arrange said desired part (52) of said means (52, 53 , 54) wall for free deformation of said initial configuration (E) to said final configuration (G).

2.

 Method according to claim 1, wherein said deformation of said sheet material (100) comprises forming said desired part (52) with a thickness less than the thickness of a remaining part (53, 54) of said means (52, 53, 54 ) of wall, specifically, in which said conformation of said desired part (52) comprises forming at least one lower wall (52) of said wall means (52, 53, 54).

3.

 Apparatus comprising means for moving along a direction (F) of movement a material

(100) thermoformable sheet through a forming station (2) of said sheet (100), in which forming means (3) are arranged arranged to deform parts of said sheet material (100) to make at least one cavity (51) of a container (50), a filling station (4), wherein said at least one cavity (51) is filled with a product (80), a closing station (5) for superimposing and fixing a additional sheet material (200) in said sheet material (100) for the purpose of closing said at least one cavity (51), said forming means (3) being arranged to be made in wall means (52, 53, 54) of said at least one cavity (51) a desired part (52) that is deformable to vary an internal volume of said closed cavity (51), said apparatus comprising a cutting station (11) located downstream with respect to said station

(5)

 of closure and wherein said containers (50) are separated from said sheet materials (100, 200), said apparatus being characterized by the fact that it comprises a turning station (13), located downstream with respect to said station (11 ) cutting, in which each container (50) rotates to arrange said deformable part

(52)

 of said wall means (52, 53, 54) for free deformation.

4. Apparatus according to claim 3, wherein said forming means (3) are arranged to form said deformable part (52) with a thickness less than the thickness of a remaining part (53, 54) of said means (52, 53 , 54) wall, and / or wherein said forming means (3) are arranged to form said deformable part so that it comprises at least one lower wall (52) of said wall means (52, 53, 54) , and / or wherein said forming means (3) are arranged to deform a plurality of cavities (51) of respective containers (50), and / or in which said closing station (5) comprises means (9) for introducing said additional sheet material (200) and superimposing the additional sheet material (200) on said sheet material (100) and joining means (10) located downstream with respect to said introduction means (9) and arranged for joining together said sheet material (100) and said material (200) l additional amining along parts (55) of edge of said cavities (51). 5. Apparatus according to claim 3, wherein said cutting station (11) comprises cutting means (12) arranged to cut said sheet material (100) and said additional sheet material (200) along parts (55) of edge of each container (50).