CONTAINER WITH A RECESS IN THE CONTAINER WALL

Description

Field of the invention

[0001] The invention relates to a container according to the preamble of claim 1. State of the art

[0002] If containers are filled with hot liquids or other contents and then closed immediately after filling, a negative pressure develops inside the container once the contents have cooled, which can cause the container walls to partially collapse. Such containers are aesthetically unsightly and cannot be placed on shelves. To prevent the walls from collapsing, the containers are equipped with a vent valve. This can be made of an air-permeable, porous material. The vent valve is usually integrated into the cap because that is the easiest place to install it. However, vent valves made of porous materials can also serve to protect the container contents from microbes and bacteria. For design or functional reasons, locating the vent valve in the container cap is not always the optimal location.There is therefore a need to allow greater flexibility in the arrangement of the ventilation valve.

[0003] WO 2010 / 081081 discloses a closure cap incorporating a porous element to enable pressure equalization between the container interior and the environment. The closure cap according to WO 2010 / 081081 has a chamber on the underside of the lid with two openings: a lower opening through which the porous element is inserted into the chamber, and an upper passage opening that connects the chamber to the environment. To ensure the porous element is held in the chamber, it can be dimensioned to ensure a snug fit. Alternatively, the lower edge of the chamber can be folded or provided with an undercut.

[0004] EP-A-1 068 902 discloses a closure assembly consisting of an elastic plug for closing a container opening and a filter medium integrated into the plug. The plug has an axial opening that allows communication between the container interior and the environment. A filter disc is arranged in the opening of the plug, sealingly abutting the cylindrical wall of the passage. It is proposed to form the filter disc in the opening integrally with the plug by injection molding. However, EP-A-1 068 902 provides no instructions as to how this could be accomplished.

[0005] DE102007002865A1 discloses a container according to the preamble of claim 1.

[0006] DE 10 2007 002 865 A1 describes an extrusion blow-molded container with a recess formed on the container wall that extends into the container interior. A membrane filter is cast within the recess. Object of the invention

[0007] The object of the present invention is to provide a holding device for functional elements on a container which can be fitted with a functional element under form-fitting conditions with little effort and yet sealingly and which can simultaneously be demolded with little effort during its production. Description

[0008] The invention relates to a plastic container with a container wall and an outlet opening.

[0009] According to the invention, the object is achieved with the container according to the preamble of claim 1 in that the insertion opening has a first clear width and the recess widens towards the interior of the container to a second clear width, wherein the second clear width is greater than the first clear width. The recess has, at least in a partial region, a roof which is formed by a section of the container wall delimiting the insertion opening, and a functional element is held in the recess in a form-fitting manner. The recess can be formed at any point on the container wall and is shaped such that the functional element is securely held in the recess after insertion through the insertion opening.If the container wall is perforated to ensure contact between the inserted functional element and a product stored inside the container, the functional element can be sealed to the container wall in such a way that a product stored inside the container cannot escape into the environment between the container wall and the functional element. Because the recess is oriented inward, the container surface remains smooth and is not impaired by elevations. The design of the container is extremely flexible, as it is not restricted by any positioning requirements for the recess. The extrusion blow molding process allows the container to be manufactured quickly and accurately.

[0010] The roof ensures that the functional element is held securely in the recess, which serves as the receiving chamber, with a form-fitting fit. The roof can be straight, convex, or concave across a central axis of the recess. The container wall in this section can also be designed as a tooth with a sharp or rounded tooth tip that roofs the recess. The recess can also be covered in more than one partial area. The roof can serve to fix the functional element in the axial direction. The roof can be designed in such a way that the functional element is removable or permanently fixed. Removability can be ensured by the application of axial force or radial force, or by a combination of both.

[0011] The recess expediently has a wall and a base. This allows the functional element or insert to be pressed into the recess until it touches the base. The wall can, for example, be pyramid-shaped or cylindrical and can form a polygon when viewed in the direction of a longitudinal extent of the recess. The wall can also be oval, elliptical, or circular when viewed in the direction of a longitudinal extent of the recess. The recess can also be formed with a shoulder which serves as a support surface or a stop surface for the functional element. In most cases, however, the wall will be circular-cylindrical.

[0012] By advantageously providing a through-opening at the base and / or wall of the recess, the functional element is connected to the interior of the container. The opening is generally positioned so that, when the functional element is inserted, the product cannot escape past the functional element. The through-opening creates a permanent connection between the atmosphere surrounding the container and the interior of the container, in addition to the outlet opening.

[0013] To simplify demoulding of the container, the recess has a central axis which is essentially perpendicular to the container wall.

[0014] According to a further exemplary embodiment, however, it is also conceivable for the recess to have a central axis which encloses an angle with the container wall which is less than 90 and greater than 0 degrees, preferably less than 88 and greater than 10 degrees, and particularly preferably less than 80 and greater than 15 degrees. This allows the orientation of the recess relative to the container surface to be flexibly selected. This is advantageous if a special container contour is required or the insertion opening should be as inconspicuous as possible. In one exemplary embodiment, the angle is less than 45° and greater than 30°. The included angle comprises both an angle in the vertical and horizontal direction. The direction specified here can relate to the base of the container.Thus, for example, the central axis can be perpendicular to the container wall in the horizontal direction, and the included angle between the container wall and the central axis of the recess can be, for example, 75° in the vertical direction. The insertion opening has a first clear width, and the recess widens toward the interior of the container to a second clear width, with the second clear width being larger than the first clear width. This allows the recess to enclose the functional element and hold it in a form-fitting manner.

[0015] In a further embodiment, the insertion opening has a first clear width, and the recess widens towards the interior of the container compared to the first clear width to a second clear width and then narrows to a third clear width. This design of the recess is advantageous when the functional element is inserted into the recess with its smaller-diameter end first. In this case, the recess is designed such that it encloses the outer surface of the functional element, and the undercut holds the larger-diameter end in a form-fitting manner. The narrowing from the second clear width to the third clear width can occur abruptly, for example by means of a shoulder, a step, or a projection. This narrowing from the second clear width to the third clear width can also occur continuously or discontinuously over a predetermined distance.The first clear width can be smaller, equal to or larger than the third clear width.

[0016] It is advantageous if the maximum roofing of the recess, measured transversely to a central axis of the recess, is between 0.05 mm and 1 mm, and preferably between 0.25 and 0.5 mm. These dimensional features ensure that the roofing has an overlap with respect to the recess, which, on the one hand, reliably holds the functional element in the recess and, on the other hand, allows the functional element to be pressed through the insertion opening. The maximum roofing is the dimension between the edge of the roofing, which also defines the insertion opening, and the wall of the recess.

[0017] Because the wall of the recess and a section of the roofing adjacent to the wall of the recess advantageously enclose an angle between 20 and 50 degrees and preferably between 30 and 40 degrees, the undercut can be demoulded and forms a sufficient force connection for connecting the functional element and the recess.

[0018] Advantageously, the recess has a substantially rotationally symmetrical shape. The recess is easier to demold than if it had a square shape. Also, the fit between the functional element and the recess is easier if the latter has a rotationally symmetrical shape.

[0019] A further aspect of the invention relates to a container as described above with a functional element accommodated in the recess. The combination of recess and functional element allows them to be precisely matched, whereby the mating surface between the functional element and the recess wall is generally liquid-tight, but can also be designed to be gas-tight if special requirements are met.

[0020] In a particularly preferred embodiment, an outer shape of the functional element and an inner shape of the recess correspond to one another in such a way that the functional element is held in the recess in a fluid-tight manner with respect to a product stored inside the container. The mating surface between the functional element and the wall of the recess can be designed to be fluid-tight. The positive connection, brought about by the roof, reliably holds the functional element in the recess, even when there is excess pressure inside the container. The roof can prevent the functional element from being displaced out of the recess in the direction of the central axis of the recess. The functional element is expediently designed as a flanged bushing. The outer contour of the functional element is adapted to the contours of the recess by the design of the collar and is therefore received in the recess in a particularly secure and sealing manner.The functional element can also have the shape of a sleeve or a bushing without a collar.

[0021] Advantageously, a second through-opening is provided on the functional element to preferably enable gas exchange between the container interior and the environment. Depending on the function of the functional element, this can be in direct contact with the container interior to equalize pressure or fulfill other tasks described below. The second through-opening can be smaller than 5 µm to retain liquid products from the container interior and can be smaller than 20 µm to retain pasty products from the container interior. With both opening sizes, unhindered gas exchange between the surrounding atmosphere and the container interior is possible. To equalize the pressure between the container interior and the environment, the second through-opening is closed by a gas-permeable membrane. The membrane is only permeable to gases and is liquid-tight.If an internal pressure builds up inside the container due to a change in altitude or gas formation that exceeds the ambient pressure, this pressure can be equalized through the membrane. It is also conceivable that a negative pressure in the container can be compensated. A negative pressure can arise, for example, when a hot product is poured into the container and then cooled in the sealed container.

[0022] The membrane function can be simplified by using a sintered, porous part made of HDPE as the functional element. The functional element is a single piece and therefore easy to manufacture. Gas can be exchanged between the container interior and the environment through the porous part, but liquid cannot pass through the functional part.

[0023] In another embodiment, the functional element is a shelf life indicator. The shelf life indicator is connected to the container interior and reacts to parameters that indicate a change in the filled product. For example, the formation of a gas or a change in pressure can be detected.

[0024] Another possibility is for the functional element to contain a chemical substance that can be in fluid contact with the container interior. For example, the continuous addition of a natural antimicrobial substance can extend the shelf life of the filled product. The chemical substance can also be an odor catcher, oxygen catcher, water vapor catcher, or CO2 catcher. In general, a chemical substance can be incorporated into the functional element to capture gases generated during storage of the container.

[0025] It is also conceivable that the functional element is an indicator which shows when the cold chain of the product stored in the container has been interrupted.

[0026] Further advantages and features will become apparent from the following description of an embodiment of the invention with reference to the schematic representations. These are not to scale: Figure 1: a cross-section through the container wall of a plastic container with a recess in a first embodiment; Figure 2: a cross-section through the container wall of a plastic container with a recess in a second embodiment; Figure 3: a cross-section through the container wall of a plastic container with a recess in a third embodiment; Figure 4: a cross-section through the container wall of a plastic container with a recess in a fourth embodiment known from the prior art and Figure 5: a side view of a plastic container with a recess.

[0027] In the Figures 1 to 4A detailed section of a container made of plastic material is shown. The container is designated as a whole by the reference numeral 11. A recess 15 is formed at an arbitrary location in a container wall 13 of the container 11. The recess 15 serves as a receiving chamber for a functional element 17. The functional element 17 is inserted into the recess 17 through an insertion opening 19. Figure 5 The recess 15 is provided, for example, in the container wall 13 of the container 11, which in the present embodiment is designed as a side wall, near the container bottom. The recess 15 is preferably arranged at a location where the functional element 17 can be in contact with the product stored in the container 11, even when the container is partially empty. In principle, any position on the container wall 13 is possible.

[0028] The recess or the receiving chamber 15, in addition to the insertion opening 19, has a wall 21 and a base 23. If the functional element 17 is received in the recess 15, it is preferred that it touches the base 23. The functional element 17 can be held in the recess 15 in a force-locking and / or form-locking manner. For holding under force-locking, the outer dimensions of the functional element 17 and the inner dimensions of the recess 15 are coordinated in such a way that a press fit is present. A force-locking holding is provided in the Figure 4 This embodiment is not part of the invention, but rather represents prior art, the description of which is intended to facilitate understanding of the invention.

[0029] To hold the functional element 17 in the recess 15 with a positive fit, the recess 15 has a roof 25. To form the roof 25, the recess 15 has a first clear width 27 in the area of ​​the insertion opening 19, which widens toward the interior of the container to a second clear width 29. The outer dimensions of the functional element 17 are essentially adapted to the roof dimensions. For this purpose, the functional element 17 widens from a collar 31 to a larger-diameter flange 33.

[0030] The difference between the first and second clear widths 27, 29 is between 0.6 and 1 mm, and preferably between 0.7 and 0.9 mm. This difference enables reliable retention of the functional element 17 in the recess 15 and allows the collar 33 to still fit through the smaller-diameter insertion opening 19, expanding the same.

[0031] The transition between the first and second clear widths 27, 29 is formed by a roofing flank 35. The flank 35 forms an angle of between 20 and 50 degrees, and preferably between 30 and 40 degrees, with the wall 21 or the central axis 37 of the recess.

[0032] If the central axis 37 is at a right angle to the parting plane of the container 11, the roof is easier to demold than with a different orientation of the central axis 37. This is because the half-shells of the container mold open in the direction of the central axis 37. However, it is also conceivable for the central axis to have an angle between 0 and 90 degrees, preferably between 10 and 88 degrees and particularly preferably between 15 and 80 degrees and the recess 15 can still be demolded. Movable elements in the tool are also conceivable to accomplish demolding. Recesses 15 with such an orientation are preferred if the container design requires it. For example, an orientation of the central axis 37 at a right angle to the container surface is advantageous for a uniform container design.

[0033] It is also conceivable that according to Figure 3the recess 15 narrows from the second clear width 29 to a third clear width 39. This configuration of the recess 15 is selected when the functional element 17 is received in the recess 15 with the collar 31 at the front.

[0034] For reasons of simplified production, the functional element 17 and the recess 15 preferably have a rotationally symmetrical shape.

[0035] To enable fluid exchange between the container interior and the environment, a first through-opening 41 can be provided at the bottom of the recess 15. It is understood that for this reason, a second through-opening 43 can also be provided on the functional element 17. As the Figures 3 and 4 show, the second through-opening 43 can be offset according to the outer contour of the functional element 17.

[0036] The functional element 17 can fulfill a wide variety of tasks. The following applications are conceivable as examples and are therefore not exhaustive: As shown in the figures, the functional element 17 can be a housing with the second through-opening 43 provided therein. A membrane 45 is inserted into the second through-opening 43. Since the membrane is expediently only permeable to gases, the pressure inside the container is always the same as in the environment. This means that gas exchange takes place between the container interior and the atmosphere surrounding the container 11. Deformation of the container 11 due to negative or positive pressure inside the container can therefore be prevented. The membrane 45 can be made of conventional membrane materials, for example polyethylene (PE) or polytetrafluoroethylene (PTFE), polyamide (PA) or polyacrylonitrile.

[0037] A simplified membrane function of the functional element 17 can be achieved by using the functional element 17 as a sintered, porous plug, for example, made of HDPE. This porous material has the properties of a gas-permeable membrane.

[0038] The functional element 17 can also serve as a shelf life indicator. For this purpose, it is connected to the container interior. If a gas forms inside the container, indicating the expiration of the product's shelf life, the functional element can change color. For example, the functional element can contain a chemical substance that changes color upon reaction with the resulting gas.

[0039] It is also conceivable that the functional element 17 contains a chemical substance that can be released into the container interior through the first and second through-openings 41, 43. This can extend the shelf life of the stored product.

[0040] A chemical substance can also be added to the functional element 17, which indicates an interruption of the cold chain and thus indicates spoiled food in the container.

[0041] Preferably, the container 11 with the above-described recess 15 is produced using the extrusion blow molding process. One possible production method is the process described in EP 2 227 369.

[0042] To produce the roof 25, a movable mandrel can be provided in one of the mold half-shells. When the half-shells are opened, the mandrel is displaced from the mold half-shell into the cavity at the same speed as the separation of the mold half-shells, so that the mandrel does not move relative to the container when the mold half-shells are opened. The mandrel is then withdrawn from the formed recess 15, with the container being held back by a counterholder.

[0043] If the recess 15 is as in Figure 4 formed, the mandrel can be pulled out of the recess 15 when the half-shells are opened, without the need for a counter-holder to hold the container back. List of reference symbols:

[0044] 11Container made of a plastic material 12Outlet opening 13Container wall 15Recess, receiving chamber 17Functional element 19Insertion opening 21Wall 23Base 25Roof 27First clear width 29Second clear width 31Collar 33Bundle 35Roof flank 37Central axis 39Third clear width 41First through opening 43Second through opening 45Membrane

Claims

1. A container (11) produced from a plastic material, comprising - a container wall (13) delimiting a container interior and - an outlet opening (12) provided on the container wall (13) for emptying a product which can be accommodated in the plastic container (11), wherein the container (11) is formed by extrusion blowmolding and a recess (15) protruding into the container interior is formed on the container wall (13) to accommodate a functional element (17), wherein the recess (15) is accessible through an insertion opening (19), wherin the recess (15) has a canopy (25) at least in a subregion, which is formed by a section of the container wall (13) delimiting the insertion opening and a functional element (17) is form fit accommodated in the recess (15), characterized in that the insertion opening (19) has a first clear width (27) and the recess (15) widens in the direction of the container interior to a second clear width (29), wherein the second clear width (29) is greater than the first clear width (27).

2. The container as claimed in claim 1, characterized in that the recess (15) has a wall (21) and a base (23).

3. The container as claimed in claim 2, characterized in that a passage opening (41) is provided at the base (23) and / or the wall (21) of the recess (15).

4. The container as claimed in any one of claims 1 to 3, characterized in that the recess (15) has a center axis (37) which is essentially perpendicular to the container wall (13).

5. The container as claimed in any one of claims 1 to 3, characterized in that the recess (15) has a center axis (37), which encloses an angle with the container wall (13), which is less than 90 and greater than 0°, preferably less than 88 and greater than 10°, and particularly preferably less than 80 and greater than 15°.

6. The container as claimed in any one of claims 1 to 5, characterized in that the recess (15) widens in the direction of the container interior in relation to the first clear width (27) to the second clear width (29) and constricts to a third clear width (39).

7. The container as claimed in any one of the preceding claims , characterized in that the maximum canopy (25) of the recess (15) measured transversely to a center axis (37) of the recess is between 0.05 mm and 1 mm and preferably between 0.25 and 0.5 mm.

8. The container as claimed in any one of claims 2 to 7, characterized in that the wall (21) of the recess (15) and a section of the canopy adjoining the wall (21) of the recess (15) enclose an angle between 20 and 50° and preferably between 30 and 40°.

9. The container as claimed in any one of the preceding claims, characterized in that the recess (15) has an essentially rotationally-symmetrical design.

10. The container as claimed in any of the preceding claims, characterized in that an outer shape of the functional element (17) and an inner shape of the recess (15) correspond to one another such that the functional element (17) is held fluid-tight in the recess (15) in relation to a product stored in the container interior.

11. The container as claimed in any one of the preceding claims, characterized in that a second passage opening (43) is provided on the functional element (17), to enable a fluid exchange between container interior and the surroundings.

12. The container as claimed in claim 11, characterized in that the second passage opening (43) is closed by a gas-permeable membrane (45).

13. The container as claimed in any one of claims 1 to 11, characterized in that the functional element (17) is a sintered, porous part made of HDPE.

14. The container as claimed in any one of the preceding claims, characterized in that the functional element (17) contains a substance which is in fluid connection with the container interior.