RELIEF VALVE

Abstract

A one-way relief valve for hermetically sealed packages is disclosed, wherein said valve comprises a valve body (100) made of a lower support surface (102) provided with vent holes (101) and a flexible membrane (110) associated with said lower support surface (102) that is capable of switching between a configuration in which the valve is closed and a configuration in which the valve is open. Said membrane (110) is characterised in that it is coloured, in order to facilitate visual inspection by the operator or the machine during the assembly of the valve and/or the production of hermetically sealed packages provided with the valve.

Claims

1. A one-way relief valve for hermetically sealed packages comprising: a valve body comprising a lower supporting surface provided with one or more vent holes and an upper surface connected with lateral walls to said lower surface, and a membrane coupled with said lower supporting surface and movable from a configuration in which said valve is closed to a configuration in which said valve is open, wherein said membrane comprises pigments and/or colorants so that said membrane is colored.

2. The one-way relief valve according to claim 1, wherein a color of said membrane is different from a color of said valve body.

3. The one-way relief valve according to claim 1, wherein said valve body is white.

4. The one-way relief valve according to claim 1, wherein said membrane is blue, green or yellow.

5. The one-way relief valve according to claim 1, wherein said membrane is configured so as to change color by reacting with one or more compounds released from the package, for instance following an oxidation reaction of the product contained into the package, for instance hydrocarbons, esters, aldehydes, ketones, alcohols, acids.

6. The one-way relief valve according to claim 1, wherein said valve body comprises an upper surface connected to said lower supporting surface with lateral walls, wherein said membrane is not covered by elements fixed to said upper surface or to said lateral walls, so as to be immediately visible to a user.

7. The one-way relief valve according to claim 1, wherein said colored membrane adheres to said lower supporting surface by means of a layer of oil, so that no further fixing means are required to keep said membrane adhered to said valve body.

8. The one-way relief valve according to claim 7, wherein said layer of oil comprises silicone oil.

9. The one-way relief valve according to claim 1, wherein said membrane comprises at least one biodegradable material, for example a biodegradable material according to one or more of the following regulations: EN 13432, EN 14995, ASTM D 6400, ISO 18606:2013, ISO 17088:2008 and UNI 11183.

10. The one-way relief valve according to claim 9, wherein said biodegradable material is polylactic acid (PLA).

11. The one-way relief valve according to claim 1, wherein said membrane comprises at least one recyclable material, for example a recyclable material according to one or more of the following regulations: directive 94/62/EC, ISO 18604:2013 and ISO 18606:2013.

12. The one-way relief valve according to claim 1, wherein said valve body comprises at least one biodegradable material, for example a biodegradable material according to one or more of the following regulations: EN 13432, EN 14995, ASTM D 6400, ISO 18606:2013, ISO 17088:2008 and UNI 11183.

13. The one-way relief valve according to claim 1, wherein said valve body comprises at least one recyclable material, for example a recyclable material according to one or more of the following regulations: guidelines 94/62/EC, ISO 18604:2013 and ISO 18606:2013.

14. An airtight package, preferably for food, comprising a one-way relief valve according to claim 1.

15. The airtight package according to claim 14, wherein said airtight package is realized at least partially or entirely in transparent material, so that said relief valve is visible from the outside.

16. A method for establishing the correct assembly of a one-way relief valve for hermetically sealed packages comprising: a valve body comprising a lower supporting surface provided with one or more vent holes and an upper surface connected with lateral walls to said lower surface, a membrane coupled with said lower supporting surface and movable from a configuration in which said valve is closed to a configuration in which said valve is open, wherein said membrane comprises pigments and/or colorants so that said membrane is colored, and said method comprises an optical detection step of said membrane, for example on the basis of the color, in order to verify the presence of said membrane.

17. The method according to claim 16, wherein said one-way relief valve is a valve according claim 1.

18. A machine for the production of hermetically sealed packages comprising a one-way relief valve comprising: a valve body comprising a lower supporting surface provided with one or more vent holes and an upper surface connected with lateral walls to said lower surface, a membrane coupled with said lower supporting surface and movable from a configuration in which said valve is closed to a configuration in which said valve is open, wherein said membrane comprises pigments and/or colorants so that said membrane is colored, and said machine comprises optical detection means configured to detect the presence of said membrane on the valve, for example on the basis of the color.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0030] The present invention will be described with reference to the accompanying figures, wherein the same numbers and/or reference signs indicate the same and/or similar and/or corresponding parts of the system.

[0031] FIG. 1 schematically illustrates a 3D view of a relief valve with a coloured membrane according to an embodiment of the present invention.

[0032] FIG. 2 schematically illustrates a 3D view of the valve body of a relief valve according to an embodiment of the present invention.

[0033] FIG. 3 schematically illustrates a side section view of the relief valve with coloured membrane from FIG. 1.

DETAILED DESCRIPTION

[0034] In the following, the present invention will be described with reference to particular embodiments, as illustrated in the accompanying figures. However, the present invention is not limited to the particular embodiments described in the following detailed description and illustrated in the figures, but rather the described embodiments simply exemplify the various aspects of the present invention, the scope of which is defined by the claims. Further modifications and variations of the present invention will be apparent to the person skilled in the art.

[0035] In the context of the present description, the terms “upper” and “lower” refer to different heights with respect to the vertical axis H originating in the centre of the valve and represented in FIG. 3. In particular, the term “lower” indicates an element on a level closer to the origin of the vertical axis H.

[0036] FIG. 1 schematically shows a 3D view of a one-way relief valve according to an embodiment of the present invention. The valve comprises a valve body 100 comprising two flat surfaces located at different heights, a lower supporting surface 102 and an upper surface 103, connected to each other by means of side walls 104. Preferably, the lower supporting surface 102, the upper surface 103 and the side walls 104 form a single valve body.

[0037] A coloured membrane 110 is placed on the lower supporting surface 102 of the valve. Said membrane is coloured in any colour other than the colour of the valve body 100, so as to be easily recognisable by an operator or a machine during the assembly of the valve and/or the production of the packages provided with said valve. The body of the valve 100 is preferably white. For example, the coloured membrane 110 may instead be blue, green or yellow. The coloured membrane 110 is thin, preferably having a thickness in the range of 0.012 mm to 0.2 mm, preferably having a thickness of 0.04 mm, so as to be sensitive to small variations in the pressure exerted by the gas inside the container. Since the membrane is thin, the fact that it is coloured is very advantageous in order to allow it to be recognisable from the outside. In fact, if it were transparent and not coloured, it would be very difficult to detect its presence by an operator and/or a machine during the production process of the valve.

[0038] FIG. 2 shows a 3D view of a particular embodiment of the valve body 100. The lower supporting surface 102 of the valve body 100 comprises four vent holes 101.

[0039] FIG. 3 shows a side section of the one-way relief valve shown in FIG. 1. The adhesion of the coloured membrane 110 to the lower support surface 102 is enabled by the presence of a layer of oil 111, so that no additional fasteners of the coloured membrane 110 to the lower support surface 102 are required. For example, the layer of oil 111 may be silicone oil for alimentary use. Silicone oil is particularly suitable for use in relief valves for packages, because it has such a viscosity that the membrane is adhered to the valve body and can be opened if gas is released from the product in the package.

[0040] FIG. 3 also shows that the upper surface 103 is made in such a way that it does not cover the lower support surface 102 with any of its parts; in this way, the coloured membrane 110 can be easily recognised by an operator or a machine during the various steps of assembly and production of the valves and/or of the hermetically sealed packages equipped with a valve because, in addition to being coloured, it is not covered by any element.

[0041] The relief valve, once assembled, can be applied to the inside of the hermetically sealed package so that the upper surface 103 is in contact with the inside wall of the package and so that the lower supporting surface 102 with the vent holes is placed towards the product.

[0042] The coloured membrane 110 is flexible and can switch from a position where the valve is closed, because the vent holes 101 of the valve body are entirely covered by the membrane retained by the layer of oil 111, to a position where the valve is open, because the membrane has at least partially detached itself from the layer of oil 111, clearing the vent holes 101 of the valve body as a result of the pressure of the gas released by the product contained in the package.

[0043] The membrane 110 is coloured with any colour other than the colour of the valve body, so as to be easily recognisable by the operator and/or the machines during the assembly of the valves and/or the production of the packages equipped with the valves. In this way, when the valves are attached to the hermetically sealed packages, it is particularly easy to ensure that they have been correctly assembled and that they include the coloured membranes. As a result, the risk of producing packages with valves that do not have membranes, which would cause the product to be unintentionally exposed to the external environment and thus lose its organoleptic properties, is reduced.

[0044] The coloured membrane 110 and/or the valve body 100 are, for example, made of biodegradable materials, e.g. polylactic acid (PLA), in order to be environmentally friendly.

[0045] Alternatively, the coloured membrane 110 and/or the valve body 100 may be made of recyclable materials in order to be environmentally friendly. For example, the valve body may be made of polyethylene (PE) and the membrane may be made of polyethylene terephthalate (PET).

[0046] Although the present invention has been described with reference to the embodiments described above, it is clear to the skilled person that various modifications, variations and improvements of the present invention are possible in the light of the teachings described above and within the scope of the appended claims, without departing from the object and scope of protection of the invention.

[0047] For example, even if a valve is shown in which the coloured membrane has the shape of a small disc, it is clear that it is also possible to make the coloured membrane with other shapes, for example with a square or rectangular shape. Similarly, even if a valve is shown in which the valve body has a circular perimeter, it is apparent that it is also possible to make the valve body with other shapes, for example with a square or rectangular perimeter.

[0048] Furthermore, although it has been described that the valve body can be white, it is evident that it is also possible to make the valve body in other colours and to adapt the colour of the coloured membrane accordingly so that it differs from the colour of the valve body and is, therefore, easily visible by the operator or the machine during the production of the valve and/or the hermetically sealed packages provided with the valve.

[0049] Finally, those areas, which are considered to be known to the skilled person, have not been described in order to avoid unnecessarily overshadowing the described invention.

[0050] For example, it has not been described how to assemble the one-way relief valves wherein the membrane is attached to the valve body by a layer of oil, since this process is known to those skilled in the art. Furthermore, it has not been described how to produce hermetically sealed packages equipped with one-way relief valves with a coloured membrane such as those described in the present invention, since this production method is similar to the one employed for producing hermetically sealed packages equipped with any relief valve and is, therefore, known in the state of the art.

[0051] Accordingly, the invention is not limited to the embodiments described above, but is only limited by the scope of protection of the appended claims.