Package for food products

Abstract

A package for a product, such as a food product, comprising a first half-shell and a second half-shell shaped like a cap, the first half-shell and the second half-shell having respective flanges surrounding an opening profile and being connected to each other at the respective flanges, at least one of the half-shells being closed by a respective sealing foil; the first half-shell and the second half-shell and the corresponding sealing foil are optionally provided with corresponding attachment structures located at the flanges for opening the package, characterized in that:-the first half-shell and the second half-shell are each formed from a shaped sheet of paper material,-said at least one sealing foil consists of a laminated material, the laminate includes at least one paper main layer, a heat sealable surface coating applied to a face of the foil facing the respective half-shell, and a heat sealable or ultrasonic weldable surface coating applied to a face of the foil facing the other half-shell, the heat sealable surface coating preferably being polyethylene or high density polyethylene.

Description

TECHNICAL FIELD

[0001] The present invention relates to a package, in particular for food products, of the type comprising a first half-shell and a second half-shell shaped like a cap, having respective flanges that enclose an opening profile, wherein at least one half-shell, preferably both half-shells, is closed by a sealing foil to contain the food product and / or accessories or toy items inside it. BACKGROUND

[0002] EP 919488 B1 describes a package of the above type, formed by two half-shells made of thermoformable plastic material, suitable for contact with food, and a respective sealing foil also made of plastic material.

[0003] The aim of the present invention is to provide a package of the above type, which is disintegrable and / or biodegradable and / or recyclable and is able to provide adequate gas-tight sealing properties for the food product contained in it, so as to bring the shelf life of the packaged product to a level comparable to that of products in conventional plastic packages.

[0004] A further aim of the present invention is to provide a package having a printed pattern on the outer surface of the half-shells, which is only minimally deformed after the shaping of the half-shells, unlike what happens with conventional plastic half-shells after thermoforming. SUMMARY

[0005] These aims are achieved by a package as defined in the following claims, which form an integral and unitary part of the present description.

[0006] In particular, the main feature of the present invention is that both half-shells and the respective sealing foil are made mainly of paper material, i.e. with a cellulose fiber content such that the package is paper recyclable according to the test methods recognized in the specific sector, such as the CEPI method, the Paper based Recyclability Guidelines, etc.

[0007] Further features and advantages of the present invention will become apparent from the detailed description provided below, with reference to the attached drawings and examples, which are not limitative. BRIEF DESCRIPTION OF DRAWINGS

[0008] In the drawings:

[0009] Figure 1 - is a general exploded perspective view of a package as shown in the prior art, as known from EP 919488 B1, of the type that is the object of the present invention;

[0010] Figure 2 Cross-sectional view of a half-shell for containing a food product, said half-shell having its sealing foil;

[0011] Figure 3 (a), (b) and (c) are cross-sectional views of exemplary embodiments showing the layered structure of a sealing foil, said sealing foil being preferably associated with a half-shell for containing a food product;

[0012] Figure 4 Cross-sectional view of a half-shell for containing a toy, said half-shell having its sealing foil;

[0013] Figure 5 (a) and (b) are cross-sectional views of two exemplary embodiments showing the layered structure of a sealing foil, said sealing foil being preferably associated with a half-shell for containing a toy; Figure 4

[0014] Figure 6 Exploded cross-sectional view of a package;

[0015] Figure 6 A is a schematic view of possible distribution patterns of ultrasonically weldable lacquer;

[0016] Figure 7 (a), (b) and (c) show half-shells equipped with a sealing foil, said sealing foil being only partially peelable from the respective flange,

[0017] Figure 8 show exemplary multi-layered structures of a sheet of paper material forming a half-shell, and

[0018] Figure 9 Partial exploded perspective view of a package according to the present application, said package being provided with an associated access or unfolding tool.

[0019] Figure 3 , 5 and 8 illustrate multi-layered structures, wherein the properties of the materials preferably used for these layers and their alternating manner are indicated. These indications should be understood as merely exemplary, even though they are preferred; general numerical ranges and alternative materials showing the above-mentioned features are indicated in the following description with reference to the above layers. DETAILED DESCRIPTION

[0020] In Figure 1 ​In the example of embodiment in the figures, the package 1 comprises two half-shells 2 and 3, which can respectively receive inside edible food pieces 4 and accessories 5, such as toys, which are intended to play the role of "surprises". Both half-shells are provided with respective opening portions of flanged edges or flanges 2', 3' which allow the application of respective sealing foils 6 and 7 when the half-shells 2 and 3 are closed after being filled. However, the case in which there is a single sealing foil 6 associated with the half-shell containing the food pieces also falls within the scope of the present application.

[0021] The filled and closed half-shells are then joined to each other in face-to-face matching condition, for example by means of a fixing action performed at the peripheral portions of the sealing foils 6 and 7 facing the flanges 2' and 3'.

[0022] After the joining of the two half-shells, the package has a substantially oval configuration; however, it should be understood that this configuration is not mandatory, since other configurations are naturally possible, such as a heart-shaped configuration.

[0023] Preferably, at least one or both of the sealing foils 6 and 7 has or have, respectively, an appendage or tab 60 or 70 which can be superimposed, respectively, on the corresponding appendage 20 or 30 of the respective half-shell, in order to facilitate the opening of the package.

[0024] According to one feature of the present application, the above-mentioned sealing foils are made of a laminated material comprising at least one main paper layer, a coating of heat-sealable material applied as a surface coating on the face of the foil facing the respective half-shell, such as a polyethylene film or a high-density polyethylene film, and a coating of heat-sealable or ultrasonic-sealable material applied as a surface coating on the face of the foil facing the other half-shell, wherein it is possible to interpose an intermediate layer, for example a primer layer, between the main paper layer and the coating of heat-sealable or ultrasonic-sealable material.

[0025] In the context of the present application, a primer layer is used, preferably having biological, natural properties, which is applied to the paper layer and which has the function of reducing the porosity of the paper, facilitating the application of the subsequent layers and favouring recyclability.

[0026] The reference to the paper layer as a main layer should be understood as meaning that said main layer is the layer with greater grammage in the laminated material, the grammage of this layer being at least 50% by weight, preferably at least 70% by weight, even more preferably from 80% to 85% by weight, up to 95% by weight, of the grammage of the laminated material.

[0027] Figure 3(a), (b), and (c) illustrate three preferred multilayer structures for a sealing foil 6, which is intended to be applied to a half-shell 2 for containing food products. This sealing foil must achieve barrier characteristics (particularly barrier characteristics against moisture and / or oxygen), airtight characteristics after being sealed to the corresponding half-shell, and peelability characteristics for opening that portion of the container. Furthermore, it is preferred that the foil can be ultrasonically welded to the sealing foil of another half-shell.

[0028] exist Figure 3 In an exemplary and preferred embodiment, the sealing foil 6 includes:

[0029] - A surface coating 62 obtained by applying an ultrasonically weldable lacquer, the surface coating being applied in different coating patterns according to desired recyclability characteristics, such as coverage of 100%, 50%, 25%, or coverage values ​​between these intermediate values. Figure 3 The ultrasonically weldable varnish common to the three embodiments can be deposited, for example, by applying a mixture of water and / or solvent, resin or polymer components (primarily ethylene vinyl acetate (EVA)); the weldable varnish coating typically has a concentration of 3-4 g / m 2 The weight applied;

[0030] - A coating 64 located below coating 62, which serves as a primer and is intended to reduce the absorption of the lacquer coating 62 into the underlying paper layer, thereby improving the peelability of the foil and the recyclability of the material.

[0031] The use of a coating or primer layer 64 is preferred, but not mandatory. The coating or primer layer is preferably composed of biological material (“bio-based”), preferably of polysaccharides, and can be obtained by applying, for example, a mixture of polysaccharides and water; the primer layer has a basis weight of about 2 g / m³. 2 ;

[0032] - Main paper layer, the main paper layer in Figure 3 (b) and (c) are marked with 66 and Figure 3 (a) is indicated by 66a.

[0033] The term paper layer refers to a layer formed of a material comprising or substantially composed of cellulose fibers; said material may contain any type of additives conventionally used in the production of paper or paperboard; said material may also contain optional functional additives to achieve barrier effects against gases and liquids.

[0034] This layer can typically have a strength of 80 to 110-120 g / m³. 2 The weight in grams.

[0035] exist Figure 3In the embodiment of (a), the paper layer designated by 66a is a paper layer having intrinsic barrier properties, in particular to water vapour, which makes it unnecessary to provide special coatings or additional lamination treatments.

[0036] In Figure 3 (b) and (c), the paper layer 66 is a conventional paper layer, for example having a grammage of 90 g / m 2 .

[0037] 68 designates a surface coating on the face of the foil facing the half-shell with which it is engaged, said surface coating being preferably formed by a film applied by lamination, said surface coating being suitable for forming a seal, preferably a heat seal, with the flange of the half-shell to which the sealing foil is applied, and having a peelability characteristic.

[0038] For example, this surface layer can consist of a polyethylene film or a high-density polyethylene film, for example having a thickness of 6 to 10 microns, preferably of the order of 8 microns.

[0039] In Figure 3 the embodiment of (b) and (c), 70(b) and 70(c) designate respectively a lamination layer having moisture barrier properties, for example made of polypropylene or polyethylene, which can be transparent or optionally metallised, and which has a thickness of, for example, 8 to 12 microns, preferably of the order of 8 microns. The above-mentioned layers 70(b) and 70(c) are not present in the structure of (a) since the layer 66(a) is a paper layer having intrinsic barrier properties. Figure 3

[0040] In Figure 2 , the reference 100 is used to designate the sealing area between the sealing foil 6 and the flange 2' of the half-shell 2, said sealing area being preferably formed by heat sealing. 102 designates the sealing area along the peripheral annular area of the sealing foil 6, said sealing area being preferably formed by ultrasonic sealing, said sealing area being made to join the two parts of the package.

[0041] Figure 4 The half-shell 3 intended to house the accessory 5 is shown in cross-section, said half-shell 3 having a corresponding sealing foil 7 welded to the flange 3' of the half-shell 3 along the annular area 100.

[0042] The sealing foil 7 can have the same layered structure as that described previously for the foil 6. However, when the sealing foil 7 is engaged to a half-shell which does not house a food product, it does not need barrier characteristics; however, it also needs a peelability characteristic to enable it to be separated from the half-shell with which it is engaged, and preferably an ultrasonic weldability characteristic to enable an access or spreading tool (spatula) 112 made of paper material to be attached to its outer surface by ultrasonic welding, as shown in Figure 9 . ​

[0043] Examples of spreading tools that can be ultrasonically welded to the sealing foil and the ultrasonic welding technique thereof are described in Applicant's EP 3838796. The ultrasonic welding is performed along a continuous or discontinuous longitudinal axis 114 of the tool, thus allowing the paper tool to be adhered to the foil without the need to apply an adhesive.

[0044] The sealing foil 7 can consist of a laminated material, whose preferred layered structure is shown in Figure 5 (a) and 5(b).

[0045] In the embodiment of Figure 5 (a), the multilayer structure of the sealing foil comprises: a paper main layer 76 having the features corresponding to the paper layer 66 of Figure 3 , and preferably having a grammage between 80 g / m 2 and 100 g / m 2 ; a film 71 made of plastic material, preferably of biaxially oriented polypropylene, having a thickness of about 8 to 12 microns, for example 8 microns, and laminated on the face of the paper layer 76 facing the other half-shell; the use of polypropylene for the film 71 is preferred both for the ultrasonic welding of the paper material spreading tool described above on the outer face of the film, and for the mutual connection of the two parts of the package, as described below.

[0046] Figure 5 The structure of (a) further comprises a heat-sealable plastic material coating 79, such as a lacquer applied to the face of the paper layer 76 facing the inside of the half-shell, which has, for example, a grammage of about 4 g / m 2 .

[0047] The layer 79 can be made of any lacquer which, in addition to making the layer 79 heat-sealable, is also able to make the foil peelable after the foil has been sealed to the flange of the respective half-shell.

[0048] The layer 79 is preferably made of a lacquer comprising a polyolefin, in particular a mixture of polyethylene and polypropylene, preferably with a higher proportion of polypropylene, in a solvent, organic or aqueous, or a lacquer comprising ethylene vinyl acetate (EVA) in the aforementioned solvent.

[0049] In the embodiment of Figure 5 (b), the multilayer structure comprises a paper layer 76 (as previously described), and a heat-sealable coating 78 formed of a polyolefin film, preferably of polyethylene or high-density polyethylene, preferably having a thickness of 6 to 12 microns, more preferably of about 6 or 8 microns, applied by lamination on the face of the foil facing the half-shell with which it is engaged, and which allows a peelable connection to be obtained after heat-sealing to the half-shell. Figure 5 The embodiment of (b) is particularly advantageous in that it allows the foil to be heat-sealed to the flange of the half-shell without the need to apply an adhesive, thus avoiding the need to use a glue gun, which is a particularly cumbersome operation, and which requires the use of a glue gun, which is a potentially dangerous tool. Figure 5The embodiment of (a) differs also in that the surface layer present on the face of the foil facing the other half-shell consists of a coating 72, for example with a grammage of about 4 g / m 2 ) obtained from an ultrasonically sealable lacquer, and an underlying primer coating 74 having the features previously described for Figure 3

[0050] Both half-shells 2 and 3 are formed from a shaped sheet of paper material.

[0051] In particular, the half-shell intended to house the food product, which in the example is designated with 2, can be formed from a multilayer composite sheet comprising:

[0052] - at least one paper layer 80, preferably two paper layers 80a, 80b;

[0053] - a surface coating 86 present on the face of the half-shell facing the respective sealing foil, which is heat-sealable and / or ultrasonically sealable and has barrier properties against moisture and / or oxygen or grease, and

[0054] - an outer protective coating 84, which is preferably applied to a layer 82 formed from printing ink, which in turn is applied to one side of the paper layer.

[0055] In the multilayer composite sheet used according to the application, the paper component, whether it is formed from a single layer or from two or more layers, represents at least 80% by weight, preferably at least 90% by weight, more preferably at least 95% by weight of the weight of the composite sheet.

[0056] Generally and preferably, in the package comprising a half-shell and the respective sealing foil according to the application, the paper component represents at least 80% by weight of the total weight of the package.

[0057] The multilayer composite sheet used to form the half-shell has formability characteristics, the above-mentioned oxygen and / or moisture or grease barrier properties, weldability characteristics, and suitability for receiving printing ink to obtain a printed graphic on the outer surface of the half-shell.

[0058] The other half-shell can have similar characteristics, however, in the case of a half-shell 3 which does not house a food product but an accessory, it is not necessary to implement the barrier properties. Due to the ubiquitous presence of cellulose fibers constituting the paper layer, which is the main layer with a higher grammage, as previously described, the recyclability properties are implemented.

[0059] The sheet preferably has an extensibility characteristic suitable to allow it to be deep-drawn, in particular the extensibility is between 3% and 15%, as determined according to the ISO 1924-3 standard.​

[0060] Such half-shells can be obtained through a deep-drawing process, for example of the type described in WO 2023 / 119121 in the name of the Applicant. This process makes it possible to obtain annular surfaces of the flanges 2' and 3' having controlled and limited corrugations, thus allowing a hermetic sealing of the respective sealing foil.

[0061] By way of non-limiting example, the paper layer can consist of a thermoformable sheet, the trade name of which on the market is Optionally, a coating treatment is carried out.

[0062] As mentioned in the preamble of the present description, the present application not only solves the problem of providing a completely recyclable package, but also solves the problem of the deformation of the printed pattern present on the outer surface of the half-shell after thermoforming of a conventional sheet or leaf made of non-biodegradable plastic material or even of a sheet of plastic material formed of biodegradable polymers.

[0063] It has been found that the formation of a paper half-shell using a sheet having an outer coating with a printed pattern greatly reduces the deformation of the pattern compared to the deformation caused by thermoforming of a correspondingly printed sheet of plastic material, which constitutes a significant advantage provided by the present application. This result is particularly relevant when the printed pattern is a graphic identification code, such as a bar code or a QR code, which must be adopted and present on a surface with high curvature in the preferred ovoid configuration of the package according to the present application.

[0064] In particular, according to the drawing technique described in WO 2023 / 119121, the printing of the text and / or of specific graphic portions, such as bar codes or QR codes, is subjected to a deformation due to a stretching of the material of no more than 15% in both the machine direction and the transverse direction, actually the X and Y axes, the remaining part of the material that needs to be drawn is fed by sliding of the sheet, in the drawing technique according to WO 2023 / 119121 the sheet is drawn by constraining it in a slidable manner to a support surface that surrounds the cavity of the die, so that the initial drawing punch is introduced into the die, the sheet can slide inside the die cavity, then deforming it by stretching the sheet.

[0065] On the other hand, the thermoforming of the plastic material causes a deformation of the text and / or of specific graphic portions, said deformation being caused only by the stretching of the material in the machine direction (X axis) and in the transverse direction (Y axis), only in direct relation to the stretching ratio (covered area / initial area of the material laid), without the material itself being subjected to sliding.

[0066] Figure 8An example is an exemplary multilayer structure of a sheet material to be shaped into a half-shell. Such a structure comprises at least one main paper layer 80, i.e. two or more paper layers, for example 80a and 80b Figure 8 (a).

[0067] In the case of use of a single paper layer, the grammage is generally comprised between 115 and 200 g / m 2 , for example about 165 g / m 2 .

[0068] In the case of use of two or more paper layers, the total grammage of the layers is comprised between 200 and 400 g / m 2 , for example 150 g / m 2 for the first layer and 165 g / m 2 for the second layer.

[0069] Preferably, at least one or both paper layers are coated papers.

[0070] The multilayer structure further comprises a surface layer 86, applied on the surface of the half-shell facing the respective sealing foil; this layer can for example be formed by a polyolefin film (preferably high or medium density polyethylene) applied by lamination, and has a thickness comprised between 10 and 60 microns. In particular, in the case of half-shells 2 involving the structure shown in Figure 8 (a), the above-mentioned surface film is preferably made of high density polyethylene, preferably having a thickness of about 40 microns.

[0071] In the case of half-shells 3, preferably applying the structure of Figure 8 (b), the surface layer 86 is preferably formed by a medium density polyethylene film, preferably having a thickness of about 14 microns.

[0072] After the sheet material is shaped into a half-shell shape having a radial flange, the above-mentioned film 86 present on the flange allows airtight but peelable sealing to the sealing foil. Moreover, this film, present in the concave portion of the half-shell, forms a barrier property against humidity and / or oxygen or grease.

[0073] Optionally, between the paper layer 80 and / or 80b and the surface layer 86 there can be an additional coating (not shown) having grease barrier properties, preferably made of an aqueous dispersion of acid-modified polyolefin.

[0074] The multilayer structure further comprises a coating 82 formed by a printing ink, typically used for rotogravure printing, deposited on the face (preferably the coated face) of the paper layer 80a or 80, typically having a weight per unit area of about 2 g / m 2The basis weight. The ink coating 82 forming a continuous printed pattern or on a surface portion is preferably covered by a coating 84 formed by a protective varnish. The protective varnish can be any commercially available varnish comprising a mixture of resin and solvent, as long as its final applied basis weight does not affect the eco-sustainability characteristics of the packaging (e.g., a basis weight of 3 g / m³). 2 For example, the protective varnish can be a polyester-based varnish (preferably PET), which may optionally contain a slip agent.

[0075] In a preferred embodiment, at least one of the two half-shells (particularly half-shells intended to contain food products) has a transparent coating with moisture-barrier properties on its outer surface, which is applied by spraying after the multilayer sheet, which has been preliminarily equipped with a printing ink coating 82, has been formed.

[0076] The above-mentioned transparent coating can be directly sprayed onto the ink coating 82 or the protective varnish coating 84.

[0077] In one embodiment, the transparent coating is obtained by spraying an aqueous or hydroalcoholic solution or suspension containing colloidal silica and / or alkoxysilanes (such as tetraalkoxysilanes and / or alkyltrialkoxysilanes) after forming.

[0078] Figure 6 The breakdown structure of the package, consisting of two half-shells 2 and 3 and corresponding sealing foils 6 and 7, is illustrated by a sectional view example.

[0079] As already noted, the sealing foil 6 can have Figure 3 One of the structures shown; for example Figure 6 The distribution pattern of the ultrasonically weldable surface coating shown in A allows the weld 108 to achieve different sealing scenarios (whether heat sealing or ultrasonic sealing) along the annular region of the flange 2', while also expanding the evaluation parameters for the material's recyclability. Figure 6 In A, the area with the highest gray intensity is marked as the area on the surface of the sealing foil where paint is applied.

[0080] The sealing foil 7 preferably has the following characteristics: Figure 5 The multi-layered structure shown.

[0081] In use, for example Figure 5 In the case of the structure illustrated in (a), the welding between the foil and the corresponding half-shell (in) Figure 6 (Illustrated by 106) can be either pure thermal welding or ultrasonic welding.

[0082] The two parts of the package are secured to each other by a welded joint formed along the annular peripheral area of ​​the respective sealing foil, the welded joint being... Figure 6 The symbol is indicated schematically and entirely by 110 and in Figure 9indicated with 110a and 110b; such welding is preferably carried out with ultrasonic welding.

[0083] As described in EP 919488, the ultrasonic welding along the annular area can be carried out by means of an ultrasonic welding electrode having an annular contact surface. Preferably, still according to the solution described in EP 919488, in the case where the half-shells have respective appendages 20 and 30 and the sealing foil also has appendages 60 and 70 which can be superimposed on the appendages of the half-shells; the two half-shells are connected to each other by welding the respective sealing foils along the annular areas 110a and 110b of the sealing foil superimposed on the flanges of the half-shells, with the exception of the welding at the appendages.

[0084] In one embodiment of the application, as Figure 7 As illustrated in (a), (b) and (c), the sealing foil 6 and / or 7 of the first and / or second half-shell is connected to the flange of the respective half-shell by a sealing portion which, in a first portion of the flange surface (typically on opposite sides of the appendage, in the case where an appendage is employed), has a greater attachment strength to the flange than to the remaining portion of the flange surface, so that the minimum force applied to enable the foil to be separated from said remaining portion does not cause the foil to be separated from said first portion.

[0085] This solution ensures that, when the consumer opens the package to consume the food product or to remove the accessory, the sealing foil remains connected to a portion of the flange surface, thus complying with the recyclability guidelines of the package which can be disposed of in a single operation in the collection of recyclable materials, avoiding the scattering of the sealing foil in the environment.

[0086] The sealing area with greater attachment strength is in Figure 7 indicated with reference numerals 90a and 90b. In one embodiment, in the case of thermal welding, greater adhesion can be obtained by applying a higher heat transfer to the surface area 90a or 90b.

[0087] In one embodiment of this solution, a welding tool is used having an annular welding surface having a plurality of adjacent areas with digital heating, the heating of which is individually controllable. This solution makes it possible to heat at different sealing temperatures along the profile of the foil, in particular employing a higher sealing temperature in certain areas (typically the areas of the tips of the ovoid profile) which are able to generate an enhanced adhesion which makes it possible to avoid the separation of the sealing foil in these areas, while employing a lower sealing temperature in the remaining areas which generates an adhesion which is able to allow the foil to be peeled.

[0088] Alternatively, greater attachment strength of the sealing foil to certain areas of the flange of the half-shell can be obtained by modifying the ultrasonic welding zone, intervening in the application profile of the ultrasonically weldable lacquer, so as to avoid separation of the foil in these areas.

[0089] Alternatively, the attachment strength of the sealing foil to certain areas of the flange of the half-shell can be made different by intervening in the geometric characteristics of the welding tool, for example by manufacturing a tool with a heating surface having different flatness, so as to avoid separation of the foil in these predetermined areas.

[0090] The production flow of the package comprises:

[0091] - forming of the half-shell, which, in the aforementioned embodiments of the half-shell, is preferably achieved by drawing of the multilayer paper sheet;

[0092] - filling of the half-shell by introducing the substance or food product and / or toy into the cavity of the half-shell,

[0093] - sealing of the filled half-shell with the respective sealing foil according to the above described method (heat or ultrasonic welding of the foil along the annular flange of the half-shell), and

[0094] - joining of the half-shells to each other along the annular peripheral area of the sealing foil.

[0095] Preferably, in order to obtain a package with shape stability, a deep-drawing post-operation (or "coining", "solidification") is performed on the deep-drawn or otherwise shaped half-shell, in the die used for deep-drawing or in a die similar to the one used for deep-drawing, before the filling and sealing operations, which allows the post-restoration of the shape of the shaped half-shell; preferably, the deep-drawing post-operation is preferably performed in the die used for deep-drawing or in a die similar to the one used for deep-drawing, said die comprising a concave die and a convex die, configured identically to the deep-drawing die, and having a pressure element suitable for constraining the flange of the half-shell to the surface of the concave die that surrounds the cavity thereof, and to apply heat and pressure to restore the initial shape and stabilize it.

[0096] This additional operation avoids the elastic return of the multilayer sheet subjected to deep-drawing, and facilitates the sealing operation with the sealing foil, thus achieving a better aligned sealing. Furthermore, the deep-drawing post-operation improves the attachment of the sealing foil to the annular flange of the half-shell, thus smoothing any wrinkles generated on the annular flange as a result of the deep-drawing operation of the multilayer paper sheet.

[0097] Therefore, such additional operations, performed before or immediately after or simultaneously with the filling, are particularly advantageous and desirable when the sheet subjected to deep drawing is stored for a certain time before the filling operation, or when the deep drawing operation, the filling operation and the sealing operation are not carried out on a continuous line.

[0098] As mentioned above, the production process also preferably comprises the following operation: spray application of a transparent coating with moisture barrier properties, as previously described, on the outer surface of the already shaped or deep-drawn multilayer sheet; this spray application operation can be carried out after the shaping or deep-drawing operation, or after the optional post-deep-drawing operation and before the filling.

Claims

1. A package for products, such as food products, comprising a first half-shell (2) and a second half-shell (3) shaped like a cap, having respective flanges (2', 3') enclosing an opening profile and being joined to each other at the respective flanges, at least one of the half-shells being closed by a respective sealing foil (6, 7); the first half-shell (2) and the second half-shell (3) and the respective sealing foil (6, 7) being optionally provided with respective appendages (20, 30) for opening the package at the flanges, characterized in that: - the first half-shell (2) and the second half-shell (3) are each formed by a shaped sheet of paper material, - the at least one sealing foil (6, 7) is composed of a laminate comprising at least one paper main layer (66; 66a; 76), a heat-sealable surface coating (68; 78; 79) applied on the face of the sealing foil facing the respective half-shell, and a heat-sealable or ultrasonic weldable surface coating (62; 71) applied on the face of the sealing foil facing the other half-shell. - the surface coating (68; 78) applied on the face of the sealing foil facing the respective half-shell comprises a laminate film of polyethylene or high-density polyethylene.

2. The package of claim 1, wherein, - the surface coating (79) applied on the face of the sealing foil facing the respective half-shell is obtained by applying a heat-sealable lacquer.

3. The package of claim 1, wherein, - the surface coating (62) present on the face of the sealing foil facing the other half-shell is obtained by applying an ultrasonic weldable lacquer comprising a mixture of ethylene vinyl acetate and solvent or water.

4. The package of claim 1 or 2, wherein - the sealing foil comprises a primer layer (64) comprising a mixture of natural biological substances, in particular water and polysaccharides, interposed between the lacquer coating (62) that can be ultrasonically welded and the at least one paper main layer (66).

5. The package of claim 4, wherein, - the surface coating (71) present on the face of the sealing foil facing the other half-shell is formed by a polypropylene film applied by lamination.

6. The package of claim 3, wherein, - the shaped sheet forming the half-shell is a multilayer composite extensible sheet comprising:

7. The package of any one of claims 1 to 6, wherein, - at least one paper layer (80; 80a, 80b), and - a surface coating (86) present on the face of the half-shell facing the respective sealing foil, the surface coating (86) being heat-sealable and / or ultrasonically sealable and having barrier properties against moisture and / or oxygen or grease. - the surface coating (86) present on the face of the half-shell facing the respective sealing foil is a high-density or medium-density polyethylene film applied by lamination, the surface coating (86) being heat-sealable and / or ultrasonically sealable.

8. The package of claim 7, wherein, - the shaped sheet forming the half-shell is an extensible sheet having an extensibility of 3% to 15% (determined according to the ISO 1924-3 standard).

9. The package of any one of claims 1 to 8, wherein, - the shaped sheet forming the half-shell is an extensible sheet having an extensibility of 3% to 15% (determined according to the ISO 1924-3 standard).

10. The package according to one of claims 1 to 9, characterized in that The sheet of paper material forming at least one of the half-shells further comprises a printed ink layer (82) having printed ink applied to one face of the paper layer (80; 80a, 80b) and a surface protective coating (84) applied to cover the printed ink layer (82).

11. The package of claim 1, wherein Each of the half-shells (2, 3) is associated with a respective sealing foil (6, 7) and wherein one of the first or second half-shells (2) comprises a food substance (4) and is formed from a multi-layered composite extensible sheet comprising: - at least one paper layer (80), preferably two paper layers (80a, 80b), - a surface coating (86) applied by lamination to the face of the half-shell facing the respective sealing foil, the surface coating (86) being heat sealable and / or ultrasonic sealable, having barrier properties to moisture and / or oxygen or grease, preferably formed from a high or medium density polyethylene film, - at least one printed ink layer (82) comprising printed ink applied to the paper layer (80, 80a), and - a protective surface coating (84) applied to cover the printed ink layer (82), and wherein the respective sealing foil comprises: at least one main paper layer (66, 66a); a surface coating (68) of heat sealable or ultrasonic sealable plastic material applied to the face of the sealing foil facing the half-shell with which it is associated, the surface coating (68) being formed from a polyethylene or high density polyethylene film; an optional coating (70b, 70c) interposed between the main paper layer (66) and the surface coating (68), the optional coating (70b, 70c) being formed by lamination of a polypropylene film, having moisture and / or oxygen barrier properties and optionally being metallised; a surface coating (62) present on the face of the sealing foil facing the other half-shell, the surface coating (62) being formed from an ultrasonic sealable lacquer; and a base coat layer (64) based on natural biological substances, the base coat layer (64) being interposed between the lacquer coating (62) and the at least one main paper layer (66, 66a; 76).

12. The package of claim 11, wherein, The other of the first and second half-shells (3) contains a toy (5) or a non-food product and is formed from a multi-layered composite stretchable sheet comprising: - at least one paper layer (80), a surface coating (86) applied by lamination to the face of the half-shell facing the respective sealing foil, the surface coating (86) being heat sealable and / or ultrasonic weldable, having barrier properties to moisture and / or oxygen or grease, and preferably being formed from a high or medium density polyethylene film, - at least one printed ink layer (82) comprising printed ink applied to the paper layer (80, 80a), and - a surface protective coating (84) applied to cover the printed ink layer (82), and wherein said respective sealing foil (7) comprises: - a main paper layer (76), - a heat-sealable or ultrasonic-sealable surface coating (78, 79) applied to the face of said sealing foil facing the half-shell with which it is engaged, said surface coating (78, 79) being selected from a polyethylene film or a high-density polyethylene film applied by lamination or a layer obtained by application of a heat-sealable lacquer, and - a surface coating (71, 72) on the side of said sealing foil facing the other half-shell, said surface coating (71, 72) being selected from a layer (72) formed by an ultrasonic weldable lacquer obtained from a mixture comprising ethylene vinyl acetate and a solvent or water and a polypropylene film (71) applied by lamination.

13. The package of claim 12, wherein, Said surface coating (72) present on the face of said sealing foil facing the other half-shell is formed by an ultrasonic weldable lacquer obtained from a mixture comprising ethylene vinyl acetate and a solvent or water, said sealing foil further comprising a primer layer (74) comprising a mixture of natural biological substances, in particular water and polysaccharides, said primer layer being interposed between said lacquer coating (72) capable of being ultrasonically welded and said at least one main paper layer (76), and wherein the surface coating (78) of heat-sealable plastic material applied to the face of said sealing foil facing the half-shell with which it is associated is a polyethylene film or a high-density polyethylene film applied by lamination.

14. The package according to one of claims 1 to 10, characterized in that Said first half-shell (2) and second half-shell (3) are each provided with a respective sealing foil (6, 7), and wherein the flanges (2', 3') of said first and second half-shells and the respective sealing foils have an accessory structure (20, 30; 60, 70) for opening said package, the accessory structure (60, 70) of each sealing foil (6, 7) being superimposed or superimposable on the accessory structure (20, 30) of the respective half-shell, each sealing foil being connected to the annular flange of the respective half-shell also corresponding to said accessory structure, by heat welding or ultrasonic welding.

15. The package of any of the preceding claims, wherein, Said first half-shell (2) and second half-shell (3) are connected to each other by welding the respective sealing foils (6, 7) along the annular regions (110a, 110b) of the respective sealing foils (6, 7) superimposed on the flanges (2', 3') of said half-shells, but with the exception of the welding at said accessory structure.

16. The package of any one of claims 1 to 15, wherein, Said sealing foil (6, 7) of said first and / or second half-shell is connected to the flange (2', 3') of the respective half-shell by a weld having a greater adhesion to a first portion (90a, 90b) of the surface of said flange than to the remaining portion of the surface of said flange, so that the minimum force applied to enable the separation of said sealing foil from said remaining portion does not cause the separation of said sealing foil from said first portion, wherein said first portion is preferably opposite said accessory structure in the presence of said accessory structure.

17. The package of any one of claims 1 to 16, wherein, One of the two half-shells is provided with a respective sealing foil, characterized in that said sealing foil comprises a flat access or spreading tool (112) made of paper material interposed between said sealing foils and ultrasonically welded to one of said sealing foils.

18. The package of any one of claims 1 to 17, wherein, At least one of said half-shells comprises a transparent coating with moisture barrier properties applied by spraying on the outer surface of the half-shell already subjected to drawing.

19. A production process for the packages according to any one of claims 1 to 18, comprising the following operations: - forming said half-shells by drawing said sheet of paper; - filling said half-shells by introducing a food product and / or a play object into the cavity of said half-shells, - sealing the filled half-shells with a respective sealing foil, and - joining said half-shells to each other along the annular peripheral region of said sealing foil, characterized in that said production process comprising the following operations: - a deep-drawing post-operation on the half-shells subjected to deep drawing, said deep-drawing post-operation being carried out before the half-shell filling operation.

20. The process according to claim 19, comprising a spraying operation of a transparent coating with moisture barrier properties applied by spraying on the outer surface of the half-shell already subjected to drawing, said spraying operation being carried out after the drawing operation or after the above-mentioned post-drawing operation and before filling.

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