EP0997395B1 - Method and device for manufacturing a packaging element for products, and related packaging element and package - Google Patents

Abstract

The invention concerns a method for making a packaging element for products comprising a step which consists in perforating said packaging element. The invention is characterised in that said perforating step consists in producing in said packaging element micro-perforations each having an average surface ranging between about 9500 mu m<2> and 125000 mu m<2> and a density per unit area ranging between about 5 and 250 per m<2>. The invention also concerns a manufacturing device, the corresponding packaging element and package.

Description

The field of the invention is that of the production of elements packaging.

More specifically, the invention relates to a method of manufacturing a packaging element for products, a manufacturing device, an element packaging and corresponding packaging.

As an example, we now discuss known techniques fruit and vegetable packaging. It is clear, however, that the invention is not in no way limited to this type of product.

In a classic way, fruits and vegetables are displayed at the display without packaging. However, the presentation of fruit and vegetables without packaging is not very interesting. Indeed, fruits and vegetables removed from their natural environment, continue to breathe and exchange certain substances with the atmosphere surrounding. Thus, in high metabolic activity, fruits and vegetables are dry out by decreasing in size, or even degrade relatively quickly. Such drying does not make them more presentable or even unsuitable for consumption. Indeed, drying can even give rise to a deterioration of fruits and vegetables due to the fact that they have consumed their ultimate resources. It is therefore interesting to provide techniques preserving their resources to increase their duration conservation.

We know, in the prior art, a solution concerning packaging of fruits and vegetables.

This solution recommends the use of non-perforated polymers for pack fruits and vegetables.

The polymers used in this solution must imperatively have natural porosity properties, so as to control flows oxygen, carbon dioxide and water vapor. However, it presents a significant drawback. Indeed, the permeabilities of these polymers are not sufficient not to renew the oxygen as well as to evacuate on the one hand the carbon dioxide and on the other hand the water vapor. However, a lack of oxygen leads, in packaging, anaerobic metabolism and water vapor retention increases the rate of deterioration of fruits and vegetables, which produces the effect opposite of the one sought.

The present invention aims in particular to overcome these different disadvantages of the state of the art.

More specifically, one of the objectives of the present invention is to provide a method of manufacturing a packaging element allowing the products packed in it to optimize their exchange of substances with the outside, and in particular to allow better permeability to water vapor, without cause in the case of certain products their dehydration.

An additional objective of the invention is to provide packaging allowing packaged products to increase their shelf life and therefore their shelf life, and more effectively compared to the state of the technical.

Another objective of the invention is to provide a manufacturing device a packaging element allowing the implementation of the the invention.

Yet another object of the invention is to provide such a device optimizing the manufacturing costs of a packaging element.

• chacune, une surface moyenne comprise entre environ 9 500µm² et 125000µm² ; et
• une densité par unité de surface comprise entre 5 et 250 par m².

These various objectives, as well as others which will appear subsequently, are achieved according to the invention using a method of manufacturing a packaging element for products, of the type comprising a step of perforating said element. packaging,
characterized in that said perforation step consists in producing in said packaging element microperforations having:

• each, an average surface of between approximately 9,500 μm ² and 125,000 μm ² ; and
• a density per unit area between 5 and 250 per m ² .

The general principle of the invention therefore consists in combining two ranges precise on the one hand the average surface of each of the microperforations, and on the other hand the density of microperforations practiced in the packaging element.

Note that microperforations can occur in any type of geometric shapes as long as their average surface remains understood in the range given above.

It is clear that, the surface range of the microperforations practiced in the packaging element being medium, certain microperforations may present a surface slightly greater than the upper bound while others may have a surface slightly smaller than the lower bound of this average surface range.

It is precisely such a combination which makes it possible to control, optimally, the exchange of substances between the packaged products and the external environment. So it is possible to get an increase important shelf life of packaged products compared to the state of technique. For certain products, this increase in the duration of conservation can result in a delay in their aging and therefore a more long life expectancy.

It is important to note that this optimum control of exchange of substances is made possible by obtaining the desired permeabilities and presented by the manufactured packaging element. These different permeabilities on the "vital" substances of the products result from this combination. In others terms, the permeabilities of "vital" substances such as in particular oxygen and / or carbon dioxide are mainly due to microperforations performed in the latter.

It should also be noted that, depending on the type of product (s) to packing, we adapt the medium surface on the one hand, and the density on the other hand surface unit of microperforations made in the packaging element, in order to respect, as closely as possible, the needs in exchange (s) of "vital" substance (s) of the product (s) to be packaged.

• chacune, une surface moyenne comprise entre environ 17 500µm² et 96500µm² ; et
• une densité par unité de surface comprise entre 40 et 160 par m².

Preferably, said microperforations have:

• each, an average surface of between approximately 17,500 μm ² and 96,500 μm ² ; and
• a density per unit area between 40 and 160 per m ² .

• les cartons ;
• les papiers ;
• les polymères ;
• les métaux.

Advantageously, said packaging element consists of at least one material belonging to the group comprising:

• the cardboards ;
• the papers ;
• polymers;
• metals.

This list is not of course exhaustive.

So we can consider combining different types of material (x) between belonging to this list or others.

It is clear however that the microperforations practiced in a complex packaging element (i.e. consisting of at least two layers) of material (x)) pass completely through the packaging element (and not only certain layer (s) of material (s)).

It will be understood that the material (s) constituting the packaging element can (very) depend in particular on the nature of the product (s) to be packaged and / or of the weight presented by the latter.

• les films ;
• les sachets ;
• les barquettes ;
• les boítes ;
• les éléments semi-rigides ;
• les éléments rigides.

Preferably, said packaging element is in a form belonging to the group comprising:

• movies ;
• sachets;
• trays;
• the boxes ;
• semi-rigid elements;
• rigid elements.

This list is obviously not exhaustive.

It will be understood that one can choose the shape of the packaging element, depending in particular on the conditions of handling and / or storage of this last after packaging of the product (s) to be packaged.

Advantageously, said microperforations have a shape circular, with an average diameter between about 110 µm and 400 µm.

Thus, the fact that the microperforations are circular and of a diameter minimal facilitates the flow of substances, including that of water vapor, between the packaged product (s) and the outside environment. Indeed, the fact that the microperforations are circular and have a minimum diameter reduces the risk of obstruction, in particular by capillarity of the condensation water.

Preferably, mechanical means with spikes are used hot to perform said microperforation step of said element packaging.

It is clear however that one can envisage, thanks to the evolution of techniques, to carry out these microperforations using any type of means such that in particular means making it possible to apply an electrical discharge and / or optical means (laser for example).

In a preferred embodiment of the invention, the temperature said hot tips is between about 200 ° C and 700 ° C.

It is clear that the temperature of the hot tips is a function in particular of the nature of the packaging element to be perforated. So the temperature of hot tips for perforating for example a polyester complex will be more higher than that required to perforate a polypropylene film.

Advantageously, after said microperforation step, said packaging element has a permeability to water vapor of less than 800 gm ^-2 day ^-1 , said permeability to water vapor being measured at 25 ° C. with relative humidity. 75%.

It will be understood that the permeability to water vapor is a function of the area of microperforations as well as the nature of the material (s) constituting the packaging element.

As already explained previously, this vapor permeability of water is selected in close relation to the nature of the product (s) to pack, and the amount of water vapor it should be able to release.

Preferably, after said microperforation step, said packaging element has an oxygen permeability of between approximately 1,000 and 200,000 ml m ^-2 day ^-1 bar ^-1 (atmosphere ^-1 ), said permeability to oxygen being measured at 25 ° C with a relative humidity of 75%.

Note that this oxygen permeability is dependent on the area of microperforations. As for vapor permeability water, the oxygen permeability is chosen according to the nature of the product (s) to be packaged, which has (have) a more or less need for breathing important.

Advantageously, after said microperforation step, said packaging element has a permeability to carbon dioxide of between approximately 3000 and 200,000 ml m ^-2 day ^-1 bar ^-1 (atmosphere ^-1 ), said permeability to carbon dioxide measured at 25 ° C with a relative humidity of 75%.

As for the permeability to water vapor as well as that to oxygen, permeability to carbon dioxide depends on the area of pinholes. This permeability to carbon dioxide is also chosen depending on the nature of the product (s) to be packaged, which has (have) a need for more or less important breathing.

Preferably, said method further comprises a step of coating of said packaging element with at least one coating providing at least one characteristic specific to said element packaging.

In this way, we can improve in particular the "living" conditions of the or packaged product (s) and / or the conditions of protection and / or presentation of the packaging element.

• les caractéristiques anti-buées ;
• les caractéristiques anti-rayonnement Ultra Violet ;
• les caractéristiques anti-adhérentes.

Advantageously, said at least one specific characteristic belongs to the group comprising:

• anti-fog characteristics;
• Ultra Violet anti-radiation characteristics;
• non-stick characteristics.

This list is clearly not exhaustive.

• les produits nécessitant une respiration ;
• les produits présentant une microflore ;
• les produits nécessitant un apport d'oxygène ;
• les produits nécessitant une évacuation de vapeur d'eau excédentaire
• les produits nécessitant une diffusion contrôlée d'une substance se présentant sous forme gazeuse et/ou solide et/ou liquide ;
• les produits nécessitant une adhésion dudit élément d'emballage.

Preferably, said products belong to the group comprising:

• products requiring breathing;
• products with microflora;
• products requiring an oxygen supply;
• products requiring evacuation of excess water vapor
• products requiring controlled diffusion of a substance in gaseous and / or solid and / or liquid form;
• products requiring adhesion of said packaging element.

It is clear, however, that the invention more generally applies to the packaging of any type of product having at least one release of a substance to the external environment and / or on the contrary consuming a substance from the outside environment.

• chacune, une surface moyenne comprise entre environ 9 500µm² et 125000µm² ; et
• une densité par unité de surface comprise entre 5 et 250 par m².

The invention also relates to a device for manufacturing a packaging element for products allowing the implementation of the method described above. The device includes hot tips. According to the invention, said hot tips make it possible to obtain microperforations having:

• each, an average surface of between approximately 9,500 μm ² and 125,000 μm ² ; and
• a density per unit area between 5 and 250 per m ² .

The invention further relates to a packaging element for products produced following the implementation of the process explained above.

The invention also covers a packaging of products comprising at least one packaging element produced according to the process detailed above

Advantageously, said packaging also comprises at least one support element.

Other characteristics and advantages of the invention will appear on reading of the following description of a preferred embodiment of the invention, given as a simple indicative and nonlimiting example.

The invention therefore relates to a method of manufacturing an element product packaging to extend shelf life of product (s) packaged using, at least in part, a component packaging.

Conventionally, a perforation step is carried out in the element packaging, to allow the packaged product (s) to breathe (see FR 2345360A and US 5554250A, for example).

• chacune, une surface moyenne comprise entre environ 9 500µm² et 125000µm² ; et
• une densité par unité de surface comprise entre environ 5 et 250 par-m².

According to the invention, the perforation step consists in producing microperforations in the packaging element having:

• each, an average surface of between approximately 9,500 μm ² and 125,000 μm ² ; and
• a density per unit area of between about 5 and 250 per-m ² .

It is therefore the combination of these two precise ranges, (concerning two distinct aspects of microperforations, namely the average surface and the density per unit area) which optimally controls exchanges of substances, through the micro-perforations, between the packaged product (s) and the external environment. Such control of the exchange of substances allows significantly increase the shelf life of the packaged product (s), based on the state of the art.

Note, however, that some microperforations can be included in ranges slightly lower and / or higher than those data above.

According to an advantageous characteristic of the invention, microperforations have a circular shape, with an average diameter of between about 110 µm and 400 µm. This has the advantage of having a better flow of water vapor between the inside and outside of the packaging element and therefore avoids any obstruction of microperforations which could cause drop in permeability to the different "vital" substances of the product (s) packed (s).

In addition, the microperforations can be arranged so as to show consistency in the number of microperforations per unit area. Thus, the packaged product (s) can breathe, evenly, over any its exterior surface (s). To do this, microperforations are, by example, placed at the intersection of two sets of lines, each set of lines having parallel lines between them, so as to obtain a regularity in the crossing of these two sets of lines.

It is clear that the packaging element is intended to wrap, at least in part, the products it contains. Consequently, the permeabilities to different substances given below are understood, when the packaging (consisting of all or part of the packaging element) is closed.

• une perméabilité à la vapeur d'eau inférieure à 800 g m^-2 jour^-1;
• une perméabilité à l'oxygène comprise entre environ 1 000 à 200000 ml m^-2 jour^-1 bar^-1 (atmosphère^-1);
• une perméabilité au gaz carbonique comprise entre environ 3 000 à 200 000 ml m^-2 jour^-1 bar^-1 (atmosphère^-1).

After the microperforation step, the packaging element has, at 25 ° C and with a relative humidity of 75% in particular:

• a water vapor permeability of less than 800 gm ^-2 day ^-1 ;
• an oxygen permeability of between approximately 1,000 to 200,000 ml m ^-2 day ^-1 bar ^-1 (atmosphere ^-1 );
• a permeability to carbon dioxide of between approximately 3,000 to 200,000 ml m ^-2 day ^-1 bar ^-1 (atmosphere ^-1 ).

It is clear, however, that for some products, microperforations may have permeability (s) to water vapor, and / or to oxygen, and / or carbon dioxide which slightly exceeds the ranges above, in order to adapt the one (s) as close as possible to the needs of the product (s) packaged in order to keep it longer.

It is also clear that, when the packaging element presents natural porosity properties, water vapor permeability may exceed slightly or even relatively strongly the upper limit of the range of permeability to water vapor indicated above.

• nécessitant une respiration, tels que, par exemple, certains produits alimentaires dont les fruits, les légumes, les plats de type quatrième gamme... ;
• présentant une microflore, tels que, par exemple, les fromages, les saucissons ... ;
• nécessitant un apport d'oxygène, tels que, par exemple, les viandes ... ;
• nécessitant une évacuation de vapeur d'eau excédentaire, tels que, par exemple, les produits de panification (pain, brioche etc...), les produits à base de céréales... ;
• nécessitant une diffusion contrôlée d'une substance se présentant sous forme gazeuse et/ou solide et/ou liquide. Une telle substance est, par exemple, un parfum, un produit d'hygiène, un insecticide ...;
• nécessitant une adhésion de l'élément d'emballage tels que, par exemple, des éléments mécaniques graissés, afin notamment d'évacuer l'air excédentaire et/ou d'éviter un contact du(des) produit(s) avec une(des) substance(s) extérieure(s) à l'emballage et/ou d'éviter une contamination de l'environnement extérieur et/ou de réduire les risques de dessèchement du(des) produit(s).

The resulting increase in shelf life is of particular interest for products:

• requiring breathing, such as, for example, certain food products including fruits, vegetables, fourth range dishes ...;
• having a microflora, such as, for example, cheeses, sausages ...;
• requiring an oxygen supply, such as, for example, meats ...;
• requiring evacuation of excess water vapor, such as, for example, bread products (bread, brioche, etc.), cereal-based products, etc .;
• requiring controlled diffusion of a substance in gaseous and / or solid and / or liquid form. Such a substance is, for example, a perfume, a hygiene product, an insecticide ...;
• requiring adhesion of the packaging element such as, for example, greased mechanical elements, in particular in order to evacuate excess air and / or to avoid contact of the product (s) with one (s) ) substance (s) external to the packaging and / or to avoid contamination of the external environment and / or to reduce the risks of drying out of the product (s).

We will understand that it is the fact of having better exchanges of (s) "vital" substance (s) between the inside and outside of the package that the duration of "life" of the packaged product (s) is extended. We can, in consequence, for example, store this packaged product (s) longer, for example of the order of a few days or even a few weeks.

It is clear however that one can consider using this element packaging to wrap any type of product requiring consumption of any substance or conversely the expulsion of a substance any from or to the external environment respectively. On the one In general, we can use this packaging element to wrap a any product.

• chacune, une surface moyenne comprise entre environ 17 500µm² et 96500µm²; et
• une densité par unité de surface comprise entre environ 40 et 160 par m² ;

de façon que le(s) produit(s) puisse(nt) bénéficier d'un flux contrôlé, de manière optimale, des substances vitales dont il(s) a(ont) besoin.Preferably, the microperforations have:

• each, an average surface of between approximately 17,500 μm ² and 96,500 μm ² ; and
• a density per unit area of between about 40 and 160 per m ² ;

so that the product (s) can (s) benefit from an optimally controlled flow of the vital substances that they need.

Such ranges on the microperforations further optimize the exchange of substances between the inside and outside of the packaging. Such a optimization of substance exchanges makes it possible to conserve even more the product (s) packaged for a long time using the packaging element.

The packaging element consists of at least one material, such as by example, the cardboard (s), the paper (s), the polymer (s), the metal (s) ... It is clear that, in the case of metals, the thickness of this (these) is for example less than a few tens of micrometers. It is clear that it can be, in as a packaging element, a combination of several of these materials or others, so that the packaging element has a plurality of layers of materials (possibly linked together by a binding element, such as by example of glue). Note that, in the case of a combination, the microperforations pass through all of the materials in the same way. In in other words, microperforations are not only practiced in certain materials of the packaging element.

As an indicative example, the polymers used in the constitution of the packaging element may be polyolefins of the non-oriented type, or oriented, or bioriented. The polymer (s) used (s) present (s) advantageously a characteristic (s) such as, for example, being transparent and / or heat sealable and / or capable of being the subject of at least an impression. We can cite, for example, the bi-oriented polypropylene (again called BOPP) or other polymer (s), simple (s) or complex (s), of the type coextruded (s) or laminated (s) and / or capable (s) of withstanding a temperature polyamide oriented (also called OPA) or polyethylene terephthalate (also called PET). In the case where only one polymer constitutes the packaging element, the packaging element may have, for example, a thickness between about 5 µm to 500 µm. In the event that several polymers are used, the packaging element may have, for example, a thickness between about 25 µm to 500 µm.

The packaging element may be in any form and especially in the form of a film, a sachet, a tray, a box, a semi-rigid element, or rigid element.

In addition, the packaging element can be coated with at least one coating material providing at least one characteristic specific to the packaging element. It can, for example, be a characteristic increasing protection and / or improving the presentation of the element packaging. As a feature increasing the protection provided by the packaging element for the product (s) which the latter contains, there may be mentioned, for example, the Ultra-Violet anti-fog and / or anti-radiation characteristics and / or non-stick. It is clear that the coating material (s) used do not must not influence the permeability of the "vital" substances of the packaged product (s).

The invention also relates to a device for manufacturing an element packaging for products.

• chacune, une surface moyenne comprise entre environ 9 500µm² et 125000µm² ; et
• une densité par unité de surface comprise entre 5 et 250 par m².

According to the invention, mechanical means with hot tips are used, making it possible to obtain microperforations having:

• each, an average surface of between approximately 9,500 μm ² and 125,000 μm ² ; and
• a density per unit area between 5 and 250 per m ² .

To perform microperforations in the packaging element, the temperature of the hot tips can be for example between approximately 200 ° C and 700 ° C. It is clear that the temperature is chosen according to the material (s) constituting the packaging element and may extend beyond, for example, the order of a few degrees from the range given above. To maintain a constant temperature of hot tips to obtain reproducibility regular in the dimensioning of microperforations, hot tips undergo, for example, interior and / or exterior heating by means of resistor (s).

The invention also relates to the packaging element resulting from the process described above.

The invention also relates to a packaging made from at least one such packaging element.

The packaging may also comprise at least one element forming support contributing, at least in part, to preserving the external appearance of the packaged product (s).

Claims (17)

1. Method for production of a packaging element for products, of the type comprising a step of perforation of the said packaging element,
   characterised in that the said step of perforation consists of producing in the said packaging element micro-perforations which have:

   each, an average surface area of between approximately 9,500 µm² and 125,000 µm²; and

   a density per unit of surface area of between 5 and 250 per m².
2. Method according to claim 1, characterised in that the said micro-perforations have:

   each, an average surface area of between approximately 17,500 µm² and 96,500 µm²; and

   a density per unit of surface area of between 40 and 160 per m².
3. Method according to claim 1 or claim 2, characterised in that the said packaging element consists of at least one material which belongs to the group comprising:

   cardboard boxes;

   papers;

   polymers;

   metals.
4. Method according to claim 3, characterised in that the said packaging element is in a form which belongs to the group comprising:

   films;

   sachets;

   troughs;

   boxes;

   semi-rigid elements;

   rigid elements.
5. Method according to any one of claims 1 to 4,
   characterised in that the said micro-perforations have a circular shape, with an average diameter of between approximately 110 µm and 400 µm.
6. Method according to any one of claims 1 to 5,
   characterised in that hot-tip mechanical means are used in order to carry out the said step of micro-perforation of the said packaging element.
7. Method according to claim 6, characterised in that the temperature of the said hot tips is between approximately 200°C and 700°C.
8. Method according to any one of claims 1 to 7,
   characterised in that, after the said step of micro-perforation, the said packaging element has permeability to water vapour which is less than 800 g m^-2 day^-1, the said permeability to water vapour being measured at 25°C, with relative humidity of 75%.
9. Method according to any one of claims 1 to 8,
   characterised in that, after the said step of micro-perforation, the said packaging element has permeability to oxygen of between approximately 1,000 and 200,000 ml m^-2 day ^-1 bar ^-1 (atmosphere ^-1), the said permeability to oxygen being measured at 25°C, with relative humidity of 75%.
10. Method according to any one of claims 1 to 9,
    characterised in that, after the said step of micro-perforation, the said packaging element has permeability to carbon dioxide of between approximately 3,000 and 200,000 ml m^-2 day ^-1 bar ^-1 (atmosphere ^-1), the said permeability to carbon dioxide being measured at 25°C, with relative humidity of 75%.
11. Method according to any one of claims 1 to 10,
    characterised in that it additionally comprises a step of covering the said packaging element by means of at least one covering material, which contributes at least one specific characteristic to the said packaging element.
12. Method according to claim 11, characterised in that the said at least one specific characteristic belongs to the group comprising:

    anti-mist characteristics;

    anti- ultra violet radiation characteristics;

    anti-adhesive characteristics.
13. Method according to any one of claims 1 to 12,
    characterised in that the said products belong to the group comprising:

    products which need to breathe;

    products which have micro-flora;

    products which require an oxygen input;

    products which require discharge of excess water vapour;

    products which require controlled diffusion of a substance which is in gaseous and/or solid and/or liquid form;

    products which require adhesion of the said packaging element.
14. Device for production of a packaging element for products, the said device comprising hot tips,
    characterised in that the said hot tips make it possible to obtain micro-perforations which have:

    each, an average surface area of between approximately 9,500 µm² and 125,000 µm²; and

    a density per unit of surface area of between 5 and 250 per m².
15. Packaging element for products, the said packaging element comprising perforations,
    characterised in that the said perforations are micro-perforations which have:

    each, an average surface area of between approximately 9,500 µm² and 125,000 µm²; and

    a density per unit of surface area of between 5 and 250 per m².
16. Packaging of products, characterised in that it comprises at least one packaging element which is produced according to any one of claims 1 to 13.
17. Packaging according to claim 16, characterised in that it additionally comprises at least one element which forms a support.