Valve, and package

Abstract

According to one aspect of the invention, there is provided a pressure relief valve comprising a cup-shaped body (1) configured to be fixed to a flexible packaging material, the body having a bottom (11) and a peripheral wall (12). The bottom has at least one through hole (14) forming a passage through the body. The valve diaphragm is attached to the main body from the packaging side in the area around the through hole (14), and a sealing liquid is arranged between the main body and the valve diaphragm. The valve diaphragm thereby covers the at least one passage opening (14). On the packaging side, the bottom has an oil distribution groove system (21, 22, 23) for containing a portion of the sealing liquid, the oil distribution groove system comprising at least one outer oil distribution groove (22, 23) having a main portion extending in the circumferential direction and having a radial extension (24, 25) extending radially from the main portion.

Description

Technical Field

[0001] The invention belongs to the field of pressure reducing valves used for food packaging. Background Art

[0002] Certain food products, such as freshly roasted coffee beans or ground coffee, have a tendency to outgas over a period of time. Therefore, corresponding food packaging, such as coffee bags (coffee bags), has a pressure relief valve. The pressure relief valve allows gases (such as carbon dioxide) generated inside the packaging to escape while preventing the surrounding air from entering the packaging, so that no oxygen can enter the packaging, thereby maintaining freshness.

[0003] The pressure relief valve usually has a cup-shaped body, wherein the edge of the peripheral wall of the body is welded or glued to the inside of the packaging material. The bottom of the body and the packaging both have openings. The bottom of the body rests against a disc as a valve diaphragm, which has oil (e.g. silicone oil) as a sealing liquid between the bottom and the disc. If there is an overpressure in the packaging, the gas connected through the bottom opening lifts the disc so that the gas can escape into the inside of the body and from there out of the packaging through the packaging opening. When there is no overpressure in the packaging, the disc resting against the bottom of the body ensures a leak-proof seal.

[0004] The advantage of such pressure relief valves is that they make it possible to pack fresh food directly and deliver it to the end customer without any intermediate repackaging. This has ecological advantages in addition to ensuring freshness for the customer. However, pressure relief valves increase the environmental footprint of the packaging.

[0005] The overpressure inside the package required to trigger the pressure relief valve depends on the geometry of the body and the materials of the body, valve diaphragm and sealing fluid. Furthermore, the pressure required to trigger the pressure relief valve may depend on the package in which the pressure relief valve is used and its contents. According to the prior art, given certain dimensions of the pressure relief valve and its components, the adhesion is adjusted according to the required adhesion and the triggering pressure using sealing fluids of different compositions. However, fine-tuning the adhesion by varying the chemical composition is a challenge. Experimentation is required. In particular, it is a challenge to adjust the adhesion without affecting other properties - especially if the materials of the valve diaphragm and the body were selected with other properties in mind and there is no freedom to adjust these properties.

[0006] Therefore, the object of the present invention is to overcome the disadvantages of the pressure relief valve in the prior art. In particular, the object of the present invention is to provide a method for setting the adhesion force. Another object of the present invention is to provide a pressure relief valve whose structure makes it suitable for being made of environmentally friendly materials. Summary of the invention

[0007] According to one aspect of the present invention, there is provided a pressure reducing valve, which includes a cup-shaped body configured to be fixed to a flexible packaging material, the body having a bottom and a peripheral wall. The bottom has at least one through hole, which forms a passage through the body. The valve diaphragm is attached to the body from the packaging side (in the cup formed by the body) in the area around the through hole, and there is a sealing liquid between the body and the valve diaphragm. The valve diaphragm thus covers at least one through hole. On the packaging side, the bottom has an oil distribution groove system for accommodating a portion of the sealing liquid, and the oil distribution groove system includes at least one outer oil distribution groove, which has a main part extending in the circumferential direction and a radial extension extending from the main part to the radial direction.

[0008] The side of the bottom opposite the package side is referred to herein as the "product side".

[0009] Here, the outer oil groove is a groove located at a radially outer position of the bottom, which means that it is arranged at a position with a certain radial distance from at least one through hole. In particular, the outer oil groove can be closer to the peripheral wall rather than the center of the bottom.

[0010] As is known in the art, the body may include an oil distribution groove on the bottom packaging side. An oil distribution groove is a shallow indentation in the surface area of ​​the body against which the valve diaphragm rests. The oil distribution groove is used to contain excess sealing liquid and act as a reservoir for it. An oil distribution groove is beneficial and often necessary to ensure that the space between the valve diaphragm and the surface against which it rests is always evenly supplied with sealing liquid.

[0011] According to this embodiment, the oil distribution groove has a further function, namely, adjusting the adhesion, in addition to this well-known function.

[0012] In particular, the radial extension of the oil distribution groove can effectively shorten the shortest path between the volume connected to the at least one through hole and any other hollow space along the valve diaphragm. Here, the volume connected to the at least one through hole can be formed by the through hole itself, or by a recess / groove around the through hole, such as the inner oil distribution groove. According to the method described herein, the next other hollow space is the outer oil distribution groove itself. The length of this path is one of the parameters that define the trigger pressure: the shorter the path, the smaller the adhesion force that needs to be overcome to lift the pressure relief valve to release the overpressure. Therefore, the adhesion force can be set using the length of this shortest path and the length of the extension itself in the embodiment.

[0013] In this way, two problems can be solved at the same time.

[0014] Firstly, when the triggering force needs to vary depending on the application, it is sufficient to adjust the length of the radial extension. The approach with radial extensions thus makes it possible to use bodies and valve diaphragms of standard size for all packages, as well as sealing fluids with a rather high tendency to adhere. Due to the extension, the effective length of the path along which the valve diaphragm adheres to the surface of the body is reduced. As a result, the pressure in the package rises until the valve is actuated and the adhesion forces to be overcome are also reduced, the greater the size of the radial extension, the greater the reduction in the adhesion forces to be overcome. Therefore, in order to adapt the valve to different applications requiring different actuation pressures / triggering pressures, only one parameter needs to be varied, namely the size of the radial extension (radial dimension). This is a single geometric parameter and its effect is predictable.

[0015] Secondly, this arrangement makes it possible for the valve diaphragm and the surface against which it rests to be flat for different types of materials. According to the prior art, it is sometimes necessary to provide a curved membrane so that the adhesion forces do not become too strong, so that the elasticity of the membrane counteracts the adhesion forces to a certain extent. However, this has the disadvantage that if the properties of the valve diaphragm material change, for example due to aging or absorption of moisture, the properties of the pressure reducing valve will also change. In particular, environmentally friendly biodegradable materials have this tendency. The method according to the invention ensures that the effective length of the path along which the valve diaphragm adheres to the surface of the body is reduced due to the extension. In this way, it provides a method for overcoming the shortcomings of the prior art, so that environmentally friendly materials can be used as valve materials.

[0016] The radial extension approach allows all packages to use body and valve membranes of standard dimensions and sealing fluids with a relatively high tendency to adhere.

[0017] In an embodiment, the radial extension or at least one of the radial extensions is a radially inward extension.

[0018] In these embodiments, if the radially inward extension extends closer to the volume connected to the hole than any other structure, the shortest path between the volume connected to the at least one through hole and any other hollow space along the valve diaphragm can be from the volume connected to the at least one through hole to the innermost point of the inward extension.

[0019] In one set of embodiments, the body comprises a plurality of outer oil distribution grooves. For example, the outer oil distribution grooves may comprise an annular array of at least two outer oil distribution grooves, which together form a (interrupted) ring.

[0020] In particular, the outer oil sump may include an annular array of first outer oil sumps and an annular array of second outer oil sumps, the first outer oil sumps being arranged around the second outer oil sumps. In such a configuration, the second outer oil sumps may be staggered relative to the first outer oil sumps, such that the second outer oil sumps cover the gaps between the first outer oil sumps, whereby there is no radial line from the center of the bottom to its periphery (to the peripheral wall) that is not interrupted by the outer oil sump.

[0021] In the embodiment where the outer oil distribution grooves are arranged in at least one annular array, each oil distribution groove may have one inward extension. If there are multiple annular arrays, it is sufficient for each oil distribution groove of one array to have one inward extension.

[0022] In an embodiment with two annular oil distribution groove arrays, the radially inward extensions may be inward extensions of the first outer oil distribution grooves. They may extend through the gaps between the second outer oil distribution grooves, optionally extending to a position radially inward of the second outer oil distribution groove positions.

[0023] In addition to the above-mentioned function of adjusting the adhesion, the radially extending portion can also balance the distribution of the sealing liquid between the first and second outer oil grooves.

[0024] In an embodiment with two annular oil distribution groove arrays, the second outer oil distribution groove may include a radially outward extension portion, which extends outward into the space between the first outer oil distribution grooves, thereby further improving the distribution of the sealing liquid between the oil distribution grooves.

[0025] In addition to the outer oil distribution groove, the oil distribution groove system may also include an inner oil distribution groove extending around the at least one through hole. The outer oil distribution groove may be deeper than the inner oil distribution groove (if any).

[0026] The main body may include an extended accommodating groove inside the peripheral wall in a plane defined by the valve membrane. The extended accommodating groove provides a space into which the valve membrane can expand so that the valve membrane will not bulge when expanding, for example when the valve membrane is wet.

[0027] The surface portion of the body against which the valve diaphragm rests can be flat, rather than the curved (arched) surface portion of prior art valves. Such a flat structure can be beneficial, in particular when the valve diaphragm and / or the body are made of biodegradable materials, because the adhesion will not change when the properties of the material, such as elasticity, change slightly due to absorption of moisture or aging. The flat structure is particularly beneficial together with the extended adaptation groove, because this combination allows the precise placement of the valve diaphragm (by adapting the diameter to the inner diameter of the cup-shaped body) without the risk of the membrane becoming arched or otherwise deformed when expanded.

[0028] In some embodiments, if the package is used to contain fine-grained products, such as coffee powder (ground coffee), the valve further comprises a permeable membrane attached to the product side of the bottom, covering at least one through hole to prevent the product from blocking the through hole, while being breathable. The permeable membrane may be a fabric membrane. In this article, "fabric" is used to cover all types of flexible materials interlaced by fibers or yarns or threads, including non-woven fabrics, woven or knitted textiles or other textile structures.

[0029] In one set of embodiments, in particular if the pressure relief valve has a permeable membrane, the body has at least one recess on the product side, thereby forming a recessed portion. At least one through hole (or at least one of the through holes) has its product-side opening in the recessed portion. Thus, the through hole opening on the product side is offset relative to the outermost plane on the product side. This means that if a permeable membrane is present, the through hole opening is offset relative to the plane of the permeable membrane. The recessed portion can effectively constitute a system of venting grooves with spacers in between.

[0030] In an embodiment, the spacer has rounded edges.Thereby, when the package is subjected to mechanical stress, there is less risk of damaging the permeable membrane.

[0031] In some embodiments, the pressure reducing valve further comprises a fixing member. The fixing member is shaped to be placed on the packaging side of the valve diaphragm. It prevents the valve diaphragm from falling out of the body even in the event that the pressure reducing valve is subjected to large mechanical shocks. If the pressure reducing valve is provided in the form of bulk material, the pressure reducing valve may be particularly subject to such shocks during transportation and assembly. In the event of a mechanical shock, the fixing member enables the valve diaphragm to remain in place, even if the adhesion of the sealing liquid may not be sufficient to do so. The fixing member may be fixed relative to the body by forming an undercut in the peripheral wall of the body so that the fixing member can be pressed into the body.

[0032] In some embodiments, the pressure relief valve may be biodegradable, i.e., all components may be made of biodegradable materials. As described above, the structure of the oil distribution groove makes the valve particularly suitable for a valve diaphragm of biodegradable material and / or a body of biodegradable material. In some embodiments, other components may also be biodegradable.

[0033] In this document, "biodegradable" may mean biodegradable according to European Standard EN 13432 (as of the end of 2021). Additionally or alternatively, it may mean biodegradable according to European Standard EN 14995 (as of the end of 2021). Therefore, "biodegradable" particularly means "biodegradable according to EN 13432 and / or according to EN 14995".

[0034] In the case of water-soluble polymers mentioned in this context, such water-soluble polymers are selectively degradable in sewage treatment plants in accordance with DIN EN ISO 9888 (as of the end of 2021) (aerobic biodegradability); determined according to the so-called Zahn-Whillens test.

[0035] In particular, at least one component of the pressure relief valve, such as the body, may be made of a polymer composition comprising a water-soluble polymer. In some embodiments, the polymer composition further comprises a salt, in particular a hygroscopic salt.

[0036] In addition to the water-soluble polymer and the salt, the composition may also contain a plasticizer. The plasticizer may be selected from the group consisting of polyols (oligohydroxy compounds and polyhydroxy compounds) and low molecular weight amides.

[0037] In some embodiments, the body and, if present, the permeable membrane and the fixing member are each made of a polymer composition comprising polyvinyl alcohol (PVOH) as a water-soluble polymer, a salt, and glycerol as a plasticizer.

[0038] In some embodiments, the valve membrane is made of a water-insoluble but biodegradable polymer composition, such as polyhydroxybutyrate (PHB).

[0039] In addition to being related to a pressure reducing valve, the present invention also relates to a packaging, in particular a coffee bag for coffee beans or ground coffee. The packaging comprises a flexible, pliable packaging material and a pressure reducing valve as described herein. The body of the pressure reducing valve is attached to the packaging material. In particular, the annular end face of the pressure reducing valve can be attached to the packaging material, wherein the valve diaphragm (and, if present, the fixing member) is arranged in a cavity between the bottom of the body and the packaging material. The packaging material is usually airtight, but has an opening or other permeable structure at a position surrounded by the peripheral wall of the body. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The embodiments of the present invention are described below in conjunction with the accompanying drawings. In the accompanying drawings, the same numbers represent the same or corresponding elements. The accompanying drawings show:

[0041] Figure 1 Exploded view of the pressure reducing valve assembly;

[0042] Figure 2 The subject's view;

[0043] Figure 3 a cutaway view of the assembled valve;

[0044] Figure 4 different views of the subject;

[0045] Figure 5 Another view of the subject;

[0046] Figure 6 another view of the assembled valve in section; and

[0047] Figure 7 The valve in the package is shown schematically. DETAILED DESCRIPTION

[0048] Figure 1 , 3 The pressure reducing valve shown in FIG. 6 includes a main body 1, which is also shown in FIG. Figure 2 , 4 and 5. The main body 1 has the overall shape of a flat-bottomed cup, with a bottom 11 and a peripheral wall 12. The bottom 11 has a sealing surface and a product side surface opposite to the sealing surface.

[0049] The peripheral wall 12 surrounds the sealing surface of the bottom 11 and has a flange 13, i.e. a shoulder protruding outward, at its end opposite the bottom 11, so that the annular end face 16 with the energy guiding ribs 18 on the packaging side is wider. The bottom has at least one through hole 14 (three through holes 14 in the described embodiment), which is covered by the valve membrane 2 that is attached to the sealing surface of the bottom 11. There is a thin layer of sealing liquid, especially oil, such as silicone oil, between the bottom 11 and the valve membrane 2. As is known, silicone oil is used for this purpose. Therefore, the sealing liquid is not described in detail in this article.

[0050] The pressure relief valve for this purpose is placed in a gas-tight flexible package, wherein the annular end face 11 of the peripheral wall is bonded to the inner surface of the package by welding or the like. The packaging material has at least one gas channel (e.g. at least one small through hole or permeable portion) at the position surrounded by the annular end face. If there is an overpressure in the package, the gas will cause the valve membrane 2 to rise from the bottom 12, thereby forming a gas channel. Excess gas can then escape through the through hole 14, between the valve membrane and the bottom and through the gas channel of the package. When there is no overpressure in the package, the valve membrane closes the package by resting against the bottom, and the sealing liquid adheres to the bottom and the valve membrane by capillary forces to form a seal.

[0051] The body 1 comprises, inside the peripheral wall 12 and in the plane defined by the valve membrane 2, an extended adaptation groove 41. It has been found that such a groove 41 is beneficial for the following reasons: the valve membrane 2 can be composed of a biodegradable polymer. It has been found that these materials may tend to change size depending on environmental conditions compared to the valve membrane materials of the prior art. For example, if they are exposed to moisture, they may swell slightly.

[0052] In an embodiment, the pressure relief valve has a permeable membrane 3 in addition to the body 1 and the valve membrane 2. The permeable membrane 3 is gas permeable compared to the valve membrane 2. For example, it can be a fabric, such as a non-woven fabric. The permeable membrane is connected to the surface of the product side of the bottom and covers at least the through hole 14. If the package contains fine-grained products, especially ground coffee, the permeable membrane is useful because it prevents the product from clogging the opening and preventing contact with the sealing liquid and the valve membrane 2. It is not necessary for packaging containing, for example, coffee beans or other large-grained products.

[0053] The permeable membrane 3 can be made of a polymer material, such as a thermoplastic fabric. In some embodiments, the permeable membrane 3 can be welded to the main body. For this reason, the main body has a product-side energy guiding rib 38 on the side facing the packaged product.

[0054] On the sealing surface side, the body has a plurality of oil distribution grooves. More specifically, the body has an inner oil distribution groove 21 surrounding the opening, and further has a circle of three first outer oil distribution grooves 22 and a circle of three second outer oil distribution grooves 23, the first outer oil distribution grooves 23 being arranged around the second outer oil distribution grooves 22. The outer oil distribution grooves 22, 23 generally extend in the circumferential direction, each having a main portion 27 extending in the circumferential direction and parallel to the peripheral wall. Each second outer oil distribution groove 23 has an outward extension 24 extending radially outward from the main portion 27 into the gaps between the first outer oil distribution grooves 22. The first outer oil distribution grooves 22 each have an inward extension 25 extending radially inward from the main portion 27 into the gaps between the second outer oil distribution grooves 23 and even further radially inward.

[0055] In this context, "radial" as well as "outwardly" or "inwardly" or "circumferentially" are referenced to the axis 10 of the body; the presence of a central axis does not necessarily imply axisymmetry, although such symmetry is an option.

[0056] The outer oil grooves have the function of serving as sealing liquid reservoirs. For this purpose, they are located in a radial position so as to be covered by the valve diaphragm (see e.g. Figure 3 or Figure 6 ). For example, when the valve is subjected to temporary mechanical loads (e.g. during transport of the valve before it is glued to the package or during transport of the package with the valve), the sealing liquid can be forced out from between the bottom 11 and the valve membrane 2. The oil distribution groove ensures that capillary forces can then suck the sealing liquid out of the oil distribution groove under the valve membrane again. Similar factors are taken into account during the manufacturing process: due to the presence of the oil distribution groove, it is sufficient to drip a drop of sealing liquid onto the bottom or the membrane, and the oil distribution groove ensures that the sealing liquid is well distributed and the sealing membrane adheres evenly to the bottom around the through hole 14.

[0057] In addition to this well-known function, the special structure of the outer oil grooves 22, 23 makes it possible to better control the adhesion forces. That is, the distance between the inner oil groove 21 and the outer oil grooves 22, 23 defines the minimum length p1 of a path along which the adhesion forces must be overcome in order to trigger the pressure relief valve by lifting the valve membrane 2 from the bottom 11. If there were no inner oil grooves, the quantity of interest would be the distance between the through hole 14 and the inward extension 25.

[0058] like Figure 5 As shown, the path length p1 can be controlled by selecting the length of the inwardly extending portion 25 .

[0059] The outward extension 24 and the inward extension 25 both have the further function of distributing the sealing liquid between the oil distribution grooves. For example, due to the presence of the outward extension 24 and the inward extension 25, the sealing liquid can be communicated between the first outer oil distribution groove and the second outer oil distribution groove, and between different first oil distribution grooves and different second oil distribution grooves.

[0060] The system includes an annular array having at least two (three in the illustrated embodiment) first external oil distribution grooves 22 and / or an annular array having at least two (three in the illustrated embodiment) second external oil distribution grooves 23. However, compared with the arrangement in which the oil distribution grooves are uninterrupted annular, the system has the following advantages: even when the pressure reducing valve remains in a constant vertical position for a long time, the sealing liquid can be well distributed along the edge of the bottom 11.

[0061] In the embodiment, the pressure reducing valve has a fixing part 4 in addition to the body 1 and the valve diaphragm 2 and, if applicable, the permeable membrane 2. The fixing part 4 is optional and can be used as a spacer between the flexible packaging material and the valve diaphragm 2 to ensure that the valve diaphragm 2 does not shift even in the event of severe mechanical shock. In the embodiment shown, the fixing part 4 is a star with three spoke ribs. It has a first distance-keeping rib 51 and a second distance-keeping rib 52. The overall star shape and the distance-keeping ribs 51, 52 constitute a shape that saves material but has a stable orientation. In addition, the star shape ensures some elasticity of the fixing part 4.

[0062] For example, Figure 6 As shown, the shape of the peripheral wall 12 forms a slight undercut 42 inside, and the inner surface of the main body is slightly conical. Due to this undercut shape, the fixing component 4 can be snapped into the main body and is kept there due to its elasticity.

[0063] On the side facing the product, the body 1 is constructed to include a venting groove system 31 and a spacer 33. This system enables the through hole 14 to be located at the bottom of the venting groove, i.e. where the surface on the product side is recessed. The radial channels 32 of the venting groove system 31 ensure that the gas diffused into the venting channel through the gas-permeable membrane can reach the through hole 14. As a result, the gas encounters less resistance and can diffuse over a relatively large surface portion, since the membrane is not pressed against a flat surface due to the overpressure inside the package. Instead, the spacer 33 keeps it away from the plane where the through hole 14 opens.

[0064] Another effect of the vent groove system is to prevent the gas permeable membrane 3 from adhering to the main body in the area around the through hole 14. Such adhering may occur during the bonding of the gas permeable membrane 3 to the main body, for example by ultrasonic welding.

[0065] For example, Figure 5 As shown, the spacer 33 has rounded edges 35 so that there is less risk of damaging the permeable membrane when the package is subjected to mechanical stress.

[0066] The overall shape of the body with the flange 13 and the widened end face 16 (which is bonded to the packaging material) further improves the process of bonding the pressure relief valve to the packaging material and the stability of the bonding. That is, the shoulder defined by the flange as an outwardly protruding shoulder forms a coupling input surface 17, on which the tool for bonding the pressure relief valve to the packaging material can directly act. Therefore, the energy (usually ultrasonic energy) coupled into the body 1 by the tool for the bonding process does not need to be coupled through the entire height (axial extension) of the body, but only through the thickness of the flange 13. This makes the bonding process more efficient compared to the case where the tool is pressed against the end face of the product side of the body.

[0067] The tool can be, for example, a tubular sonotrode, the tube diameter of which corresponds approximately to the diameter of the flange 13 .

[0068] However, the flange 13 and the widened end face 16 are only optional. In alternative embodiments, the body 1 does not have such a structure. In these alternative embodiments, the body 1 can also be welded to the packaging material by applying a sonotrode to the end face of the body on the product side. Also in these embodiments, the sonotrode used can optionally be tubular, with a tube diameter greater than the outer diameter of the area with the venting groove system and the spacer. However, alternatively, the sonotrode can have a flat outer coupling face.

[0069] In the embodiment, the main body 1, the fixing member 4 and the permeable membrane 3 are all made of a polymer composition that contains a salt in addition to a water-soluble polymer:

[0070] The body 1 and the fixing part 4 are injection-moulded from a polymer composition comprising PVOH obtained, for example, by saponification of poly(vinyl ester), a salt (especially sodium chloride) and glycerol. The polymer composition of the body and the fixing part may be identical.

[0071] The permeable membrane is a fibrous fabric made of a polymer composition, also comprising PVOH obtained, for example, by saponification of polyvinyl ester, a salt (especially sodium chloride) and glycerol.

[0072] The valve diaphragm 2 is made of PHB material.

[0073] All components are therefore biodegradable.

[0074] Figure 7 The package with a pressure relief valve is schematically shown, where the main body 1 is welded to a packaging material 60, and a through hole 61 is provided on the packaging material for releasing gas.

Claims

1. A pressure reducing valve, comprising: A cup-shaped body (1) configured to be fixed to a flexible packaging material, comprising a bottom (11) and a peripheral wall (12), wherein the bottom (11) has at least one through hole (14), wherein the through hole forms a channel passing through the body; a valve diaphragm (2), which is attached to the body from the packaging side in an area around the at least one through hole (14); and a sealing liquid located between the body (1) and the valve diaphragm (2), characterized in that the bottom (11) has an oil distribution groove system on the packaging side for accommodating a portion of the sealing liquid, the oil distribution groove system comprising at least one outer oil distribution groove (22, 23), the outer oil distribution groove having a main portion (27) extending in a circumferential direction and a radial extension portion (24, 25) extending from the main portion (27) to a radial direction.

2. The valve according to claim 1, wherein: The oil distribution tank system comprises at least one annular array consisting of at least two first outer oil distribution tanks (22).

3. The valve according to claim 2, wherein: The oil distribution tank system further comprises at least one annular array having at least two second outer oil distribution tanks (23), wherein the first outer oil distribution tanks (22) are arranged around the second outer oil distribution tanks (23), and the second outer oil distribution tanks are staggered relative to the first outer oil distribution tanks.

4. The valve according to claim 3, wherein at least one of the first outer oil distribution grooves has a radial extension (25), which is an inward extension extending inwardly to between the second outer oil distribution grooves (23).

5. The valve according to claim 3 or 4, wherein at least one second outer oil distribution groove has a radial extension (24), which is an outward extension extending outwardly between the first outer oil distribution grooves (22).

6. Valve according to any of the preceding claims, wherein the oil distribution groove system further comprises an inner oil distribution groove (21) extending around the at least one through hole (14).

7. The valve according to claim 6, wherein the at least one outer oil groove (22, 23) is deeper than the inner oil groove (21).

8. A valve according to any of the preceding claims, wherein the radial extension portion or at least one of the radial extension (25) portions is an inward extension portion, and wherein, when the valve diaphragm (2) is abutted against the body, the shortest path along the valve diaphragm (2) between the volume connected to at least one through hole (14) and any other hollow space leads from the volume connected to at least one through hole (14) to the innermost point of the inward extension portion.

9. A valve according to any one of the preceding claims, wherein at least one component of the valve is made from a polymer composition comprising a water-soluble polymer.

10. A valve according to any preceding claim which is biodegradable.

11. Valve according to any one of the preceding claims, further comprising a permeable membrane (3) in the form of a fabric fixed to the body (1) for covering at least one through hole (14) on the product side opposite to the packaging side.

12. Valve according to any of the preceding claims, wherein the body has a system of ventilation grooves between which spacers are arranged, at least one of the through holes (14) or the opening of the through hole (14) being located in a ventilation groove.

13. The valve according to any one of the preceding claims, further comprising a fixing member (4) fixed relative to the peripheral wall, such that the valve membrane (2) is sandwiched between the bottom (11) and the fixing member (4).

14. A package for packaging a food product, the package comprising a flexible, pliable packaging material (60) and a pressure relief valve according to any one of the preceding claims, wherein the body (1) is attached to the packaging material (60).

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