Method for producing a closure of a container

Abstract

The present application discloses a method for manufacturing a closure (1) for closing a container (100), said closure (1) comprising a closure body (10) made of paper and an internal sealing element (20) attached to the closure body (10), the method comprising the steps of: providing a sheet material (200) comprising at least a paper layer (202) and a sealing layer (204); removing an excess portion (204B) of the sealing layer from the sheet material (200) such that the excess portion of the sealing layer (204) forms an internal sealing element (20) in the sheet material (200); the sheet material (200), which previously forms the inner sealing element (20), is shaped by means of a shaping device (400) in order to achieve the closure body (10) to which the inner sealing element (20) is attached. The present application also discloses a closure (1) for closing a container (100), said closure being implemented by the aforementioned method.

Description

Technical Field

[0001] The invention relates to a method for producing a closure for closing a container and to a closure obtained by the method.

[0002] In particular, the present invention proposes a novel closure for closing a container, the closure comprising a closure body substantially made of paper and an inner sealing element attached to the closure body.

[0003] The inner sealing element is arranged to seal the open mouth of the container, for which purpose it can be eg glued or welded on the upper edge of the open mouth of the container so as to close any passage between the interior and the exterior of the container.

[0004] Preferably, the inner sealing element is arranged to remain attached to the upper rim of the container and to separate from the closure body when the closure body is first removed from the container in use.

[0005] The consumer must then remove the inner sealing element to gain access to the interior of the container.

[0006] To then reclose the container, the consumer can simply use the closure body alone, without the need for an internal sealing element. Background Art

[0007] Italian patent application No. IT102014902274922 of the same applicant already discloses a closure comprising an internal sealing element of the above-mentioned type; however, in this prior art solution, the closure body is made of plastic, not paper.

[0008] Replacing plastic with paper is one action that can be taken in the packaging sector to reduce the environmental impact of packaging.

[0009] From this perspective, the applicant redesigned the novel closure proposed in the opening part, wherein the closure body is substantially made of paper and an internal sealing element is attached to the closure body. The sealing element of the novel closure can operate the same function as the sealing element disclosed in IT102014902274922.

[0010] In the prior art, it has been proposed to manufacture closures from paper.

[0011] For example, GB3211960 discloses a flange cap made of paper and provided with a single spiral rib or groove formed near the free edge of its flange.

[0012] Other proposals for closures or caps made of paper are disclosed in US1343732, US1559028, US1422018, US2351318.

[0013] However, this prior art provides no teaching on how to integrate a sealing element into a closure made of paper. Summary of the invention

[0014] In view of this prior art, the Applicant's main object was to provide a method for producing the novel closure proposed in the opening paragraph.

[0015] As a secondary object, the Applicant's object is to provide a method for manufacturing a closure which is simple, efficient and cost-effective.

[0016] The invention proposes a method for producing a closure for closing a container and a closure obtained by the method.

[0017] The present invention generally relates to a method according to claim 1 .

[0018] The invention also relates to a closure according to claim 9 .

[0019] The claims form an integral part of the teaching provided here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other characteristics and advantages of the invention will become apparent from the following description, which will refer to the accompanying drawings, which are provided only as non-limiting examples, in which:

[0021] - Figure 1A and 1B An example of a closure manufactured according to the method described herein is shown;

[0022] - Figure 2 shows a cross-sectional view of the closure of Figure 1;

[0023] - Figure 3 Schematically showing a preferred embodiment of the method described herein;

[0024] - Figure 4 A second preferred embodiment of the method described here is schematically shown. DETAILED DESCRIPTION

[0025] The following description shows various specific details that will provide a deeper understanding of the embodiments. The embodiments can be implemented without one or more of the specific details, or with other methods, components or materials, etc. In other cases, known structures, materials or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments.

[0026] The references used herein are for convenience only and do not determine the scope or extent of the embodiments.

[0027] As mentioned above, the present invention relates to a method for manufacturing a closure for closing a container and to a closure obtained by this method.

[0028] In particular, the closures described herein include a closure body substantially made of paper and an inner sealing element attached to the closure body.

[0029] refer to Figure 1A and 1B In the embodiment of the present invention, a closure (which is indicated as a whole by reference numeral 1) is a closure for closing a container 100 in the form of a can. The container 100 has an open mouth 102, which is provided with an external thread 104 for threading the closure on the container.

[0030] By the way, it should be noted that the type of container should not be considered as limiting the scope of the present invention.

[0031] For example, the container may also be a bottle, a flask, a glass, etc., and may be made of a variety of materials, such as glass, plastic, paper, etc., or any combination thereof.

[0032] Additionally, instead of the threaded connection described above, the container may be configured for connection to the closure in some other manner, such as a snap fit.

[0033] The application of the closure described here is preferably in the food industry; other possible fields can be, for example, the cosmetics and pharmaceutical fields.

[0034] In one or more preferred embodiments, such as the illustrated embodiment, the closure 1 includes a closure body 10 having a top wall 12 and a side wall 14 .

[0035] The closure body 10 is substantially made of paper. Generally speaking, as will also appear below, the closure body 100 is indeed made of a sheet material including a paper layer; according to the method described herein, the paper layer will form the closure body alone, or in combination with one or more other layers in a multilayer structure, but wherein the paper comprises a major amount, preferably more than 90% by weight. For example, as will be shown below with reference to the preferred embodiment of the present invention, a separating layer can be attached to the paper layer. In addition or alternatively, the paper layer can also be coated with one or more coatings having, for example, barrier properties.

[0036] By way of illustration, it should be noted that the term "paper" herein will generally include any sheet material produced by mechanical and / or chemical processing of cellulosic fibers.

[0037] Preferably, the side wall 14 extends along a closed path around a reference axis I that is transverse to the top wall 12 .

[0038] The top wall 12 is preferably flat and orthogonal to the reference axis I.

[0039] In alternative embodiments, the top wall 12 may even be concave or convex at least in one region thereof.

[0040] The side wall 14 is configured to cooperate with the open mouth 102 of the container 100 .

[0041] In one or more preferred embodiments, such as the illustrated embodiment, the sidewall 14 defines an interior cavity 14B that is configured to receive the open mouth 102 of the container 100 .

[0042] In one or more preferred embodiments, such as the illustrated embodiment, the sidewall 14 includes internal threads 14A configured to engage external threads 104 of an upper mouth 102 of a container 100 to achieve a threaded connection between the closure 1 and the container 100 .

[0043] The closure 1 further comprises an inner sealing element 20 which is attached to the inner surface 12A of the top wall 12 of the closure body 10 .

[0044] In one or more preferred embodiments, such as the illustrated embodiment, the internal sealing element 20 is in the form of a sheet, such as a disc in the illustrated example, which is configured to close any passage through the open mouth 102 between the interior and exterior of the container.

[0045] The sealing element 20 may have the function of providing a hermetic closure of the container, for example for product preservation, or simply constitute an anti-tampering device.

[0046] Preferably, the inner sealing element 20 is glued or welded to the upper rim 102 of the container 100 .

[0047] Depending on the material forming the sealing element 20 , the welding of the sealing element to the upper rim 102 can be performed, for example, by heat welding or ultrasonic welding.

[0048] like Figure 1B As shown, the inner sealing element 20 is arranged so that when the closure body 10 is first removed from the container 100, the inner sealing element 20 remains attached to the upper edge 102A of the container 100 and is separated from the closure body 10.

[0049] To this end, at least the top wall 12 of the closure body 10 is preferably provided with a separation layer 22 which is in direct contact with the inner sealing element 20 and has the function of facilitating separation of the sealing element 20 from the top wall 12 when the container is first opened.

[0050] Depending on the needs and / or circumstances of a particular application, the inner sealing element 20 may have different shapes; it may also be provided with tabs to facilitate gripping by a user.

[0051] The method described herein is used to manufacture a closure 1 as described above, or more generally, a closure of the type having a closure body substantially made of paper and an internal sealing element attached to the closure body.

[0052] Generally speaking, the method described herein comprises the following steps:

[0053] - providing a sheet material comprising at least a paper layer and a sealing layer;

[0054] - removing excess portions of the sealing layer from the sheet material so that a portion of the sealing layer remaining in the sheet material forms an inner sealing element;

[0055] - Shaping the sheet material, which has previously been formed into the inner sealing element, by means of a shaping device in order to achieve a closure body with attached inner sealing element.

[0056] In other words, the method described here provides for both the closure body and the sealing element of the closure to be realized starting from the same sheet material comprising the paper layer and the sealing layer.

[0057] Such sheet materials can advantageously be produced independently of the implementation method described here, for example at a separate location.

[0058] The paper layer and the sealing layer can be connected together by a lamination process in order to form the sheet material.

[0059] Starting from this sheet material, the method first provides that the sealing element of the closure is formed in the sheet material in that excess parts of the sealing layer are removed from the sheet material.

[0060] Next, the sheet material with the sealing element integrated therein is formed by a forming device so as to realize a closure body with the sealing element provided at a predetermined position.

[0061] As will be described below, the sheet material may be in the form of a web wound into a reel.

[0062] In this case, the web is advanced and continuously extended along a working path while the two above-mentioned steps are performed on the web in two different stations along the working path.

[0063] The result is that a continuous series of finished closures are achieved from the web as it is fed along the working path, as a function of the production rate of the web's advancement speed.

[0064] Reference below Figure 3 , which schematically shows a first embodiment of the method described herein.

[0065] In the illustrated embodiment, the sheet material is provided in the form of a web 200 which is unwound from a reel 202 and advances along a working path K.

[0066] The web 200 comprises a paper layer 202 and a sealing layer 204 which are connected together, for example due to a lamination process.

[0067] Preferably, the web 200 further includes a separation layer 206 interposed between the two layers 202 and 204 .

[0068] The sealing layer 204 may include at least one of the following materials: aluminum, plastic, paper, or any combination thereof.

[0069] The separation layer 206 may include a polymer, such as fossil-based and recyclable plastics, or a biodegradable polymer, such as PHA, PBS, PLA, and the like.

[0070] In one or more preferred embodiments, the sealing layer is an aluminum foil, preferably having a thickness in the range between 10 micrometers and 30 micrometers, and the separation layer is a polymer layer.

[0071] At station 300 , the web 200 undergoes a step of removing the excess portion of the sealing layer 204 , so as to form the internal sealing layer 20 of the closure 1 directly in the web 200 itself.

[0072] In one or more preferred embodiments, such as the embodiment shown, the step includes:

[0073] - making at least one cut 212 in the sealing layer 204 along a predetermined cutting line by means of the cutting device 302 so as to divide the sealing layer 204 into at least one portion defining the inner sealing element 20 and at least one excess portion 204B; and, then

[0074] - Stripping the excess portion 204b from the web 200, while leaving the inner sealing element 20 there.

[0075] The cutting device 302 may be a mechanical device that includes a reciprocating cutter 302A and opposing blocks 302B disposed at opposite sides of the web 300 .

[0076] The cutter 302A is arranged to reciprocate transversely (or orthogonally) to the web 200 and penetrates the web 200 to a depth corresponding to the thickness of the sealing layer 204 due to its forward stroke.

[0077] The opposing block 302B may be stationary, or movable (in a reciprocating manner similar to the cutter 302A), and has the function of supporting the web 200 to resist the pressure exerted on the web 200 by the cutter 302A while it penetrates the web to form the cut 212.

[0078] In an alternative embodiment, the cutting device may be a laser cutting device and include a laser source configured to generate a laser beam capable of effecting the cut 212 in the web 200 .

[0079] The laser source may be, for example, a fiber laser or a YAG laser.

[0080] On the other hand, the peeling operation is performed by a pulling device 304 that is arranged to take the excess portion 204B of the sealing layer 204 and pull it away from the web 200 .

[0081] In one or more preferred embodiments, such as the illustrated embodiment, the excess portion 204B is in the form of a continuous band that can be gradually peeled off the web 200 as the web 200 advances along the working path K.

[0082] In one or more preferred embodiments, the pulling device 304 is a winding device having a rotating roller 304A that is connected to the leading edge of the excess tape and rotates to wind the excess tape around itself, thus stripping the tape 204B from the web 200 .

[0083] In one or more preferred embodiments, such as the illustrated embodiment, the pulling device may include at least one deflection member 304B, such as a freely rotating roller, which is configured to deflect the excess portion 204B of the sealing layer 204 in a direction away from the web 200.

[0084] Subsequently, at a station 400 arranged downstream of the station 300 , the web 200 provided with the inner sealing layer 20 and cleaned of the excess portion 204B passes through a forming device 402 to undergo a forming operation.

[0085] The forming operation comprises forming the web 200 so as to realize the closure body 10 of the closure 1 using the paper layer 212 of the web, while arranging the inner sealing element 20 previously formed in the same web 200 at a predetermined position in the finally formed closure body 10 .

[0086] In one or more preferred embodiments, such as the illustrated embodiment, the forming device 402 includes a first forming tool 402A and a second forming tool 402B, which are arranged on opposite sides of the web 200 and are configured to move between an open position and a closed position according to a reciprocating motion transverse to (or orthogonal to) the web 200. In the open position, the two tools 402A and 402B maintain a certain distance from the web 200, and in the closed position, the two tools 402A and 402B are connected together and press the web 200 from opposite sides, thereby constraining it in a forming cavity 404, which is defined by the two tools connected together.

[0087] The shaped cavity 404 has the same shape as the closure body 10 to be realized, in particular comprising a first area 404A arranged to realize the top wall 12 of the closure body 10 and a second area 404B arranged to realize the side wall 14 .

[0088] Accordingly, the web 200 has a first portion 222 arranged to form the top wall 12 and a second portion 224 arranged to form the side wall 14 ; the first portion 222 includes the inner sealing element 20 .

[0089] In the forming operation, the web 200 constrained in the forming cavities 404 of the two forming tools 402A, 402B assumes the same shape as the cavities, wherein its first portion 222 is formed to realize the top wall 12 and its second portion 224 is formed to realize the side walls 14 .

[0090] In the closure body 10 thus formed, the sealing element 20 of the second portion 224 is finally located at the inner surface of the top wall 12 .

[0091] According to an alternative embodiment, the forming operation can include a vacuum forming process, wherein the web 200 is urged against a forming surface of a mold due to a pressure difference established at opposite sides of the forming surface by a negative pressure generating system.

[0092] By the way, it should be noted that in the above embodiment, the closure body 10 is formed by the paper layer 202 and the separation layer 206. In any case, as described above, the paper layer 202 is the major amount, preferably greater than 90% by weight. It should be understood by those skilled in the art that the paper layer will achieve the self-supporting and load-bearing structure of the closure body and determine its mechanical properties.

[0093] Forming the web 200 may include controlling certain operating parameters, such as humidity, temperature, pressure applied to the web 200, duration of the forming step, etc., depending on the specific circumstances and conditions of the various applications, such as the type of paper used or the desired characteristics of the closure body to be manufactured (including in particular its shape and dimensions, its mechanical properties, form and surface quality, expected dimensional tolerances, etc.).

[0094] Those skilled in the art should understand that the above operating parameters can be determined through experiments.

[0095] In one or more preferred embodiments, such as the embodiment shown, the methods described herein further provide for cutting the web 200 so as to separate the formed closure body 10 from the web.

[0096] Preferably, the cutting operation is performed by the same forming device 400 .

[0097] For this purpose, the forming device 400 is provided with a knife 406, which is carried by the first forming tool 402A or the second forming tool 402B and is arranged so that when the two tools are moved to their closed position, the knife 406 cuts the web 200 and separates the closure body 10 formed in the forming cavity 404 from the web.

[0098] When performing the method described herein, the web 200 is preferably advanced along the working path K according to a stepping motion so that the web remains stationary while the devices 302 and 402 operate on the web, and the web moves in the time interval between one operating cycle of the two devices and the next operating cycle.

[0099] In an alternative embodiment, the web may be continuously advanced in the reverse direction along the working path K, and the devices 302, 402 are then arranged to follow the movement of the web 200 and operate on it simultaneously.

[0100] The means for moving the web 200 can be of any known type suitable for the purpose.

[0101] In one or more preferred embodiments, such as the one shown, the web 200 moves along the working path K due to the pulling action exerted on the web 200 by a pulling device 500 arranged downstream of the two stations 300 and 400 .

[0102] In passing, it should be noted that the web retains its continuous extension even after the finished closures 1 have been separated by cutting, with the difference that, at this stage, the web is not a complete sheet but has gaps left as a result of the closures 1 having been separated from it.

[0103] In one or more preferred embodiments, such as the illustrated embodiment, the pulling device 500 may be a winding device including a rotating roller 502 that is coupled to a leading edge of the web and rotates to cause the web to wind upon itself.

[0104] In an alternative embodiment, the pulling of the web 200 along the working path K described above may be performed by the same forming device 402 .

[0105] For this purpose, according to these embodiments, the forming device 402 is arranged to move according to a forward stroke along the working path K when the two forming tools 402A, 402B are in their closed position and constrain the web 200 in the forming cavity 404, so as to form the web and simultaneously move it along the working path K. The forming device 402 is also arranged to move according to a backward stroke along the working path K when the two forming tools 402A, 402B are in their open position, so as to return to the initial position and start a new forming cycle.

[0106] In view of the above, as the web 200 advances along the working path K and the above operations are performed on it at the stations 300 and 400, a continuous finished closure 1 is achieved in the web 200 and separated from the web.

[0107] The operations performed at stations 300 and 400 can themselves be performed to produce a single sealing element 20 and a single closure body 10 in one operating cycle, or alternatively, to produce a plurality of sealing elements 20 and a plurality of closure bodies 10 .

[0108] In the second case, the web is arranged to provide a plurality of first portions 212 and second portions 214 simultaneously to each station, and the apparatus 302, 402 itself is arranged to manufacture a plurality of sealing elements 20 and a plurality of closure bodies 10 in one operating cycle.

[0109] For example, the cutting device 302 may have a plurality of cutters 302A for forming a plurality of cuts 212 in the sealing layer 204 of the web 200 , and the device 402 may have a plurality of first tools 402A and second tools 402B for forming a plurality of closure bodies 10 .

[0110] Reference below Figure 4 An embodiment of the method is characterized in that the web 200 is produced in real time in an initial step of the method.

[0111] In particular, in one or more preferred embodiments, such as the illustrated embodiment (see Figure 4 ), the paper layer 202 and the sealing layer 204 are initially provided in the form of separate webs which are wound into two respective rolls 202', 204'.

[0112] Both webs 202 , 204 advance along a working path K and are joined together by a lamination process in a station 600 arranged upstream of the two stations 300 and 400 , so as to form the web 200 .

[0113] In one or more preferred embodiments, the web 204 constituting the sealing layer 204 in the laminated web 200 further includes a separation layer 206 , which is arranged to face the paper web 202 .

[0114] In one or more preferred embodiments, such as the embodiment shown (see Figure 4 ), before reaching the two stations 300 and 400, the laminated web 200 is cooled at a station 700, which is arranged downstream of the station 600 and upstream of the two stations 300 and 400 for stabilizing the connection achieved by lamination between the two webs 202, 204.

[0115] Referring now to the above-described embodiments, it should be noted how the method described herein can advantageously utilize the properties of a separation layer 206 of the web 200 that is interposed between the paper layer 202 and the sealing layer 204 .

[0116] In practice, this layer performs a dual function: when carrying out the method, it helps to peel off the excess portion 204B of the sealing layer from the web 200, and in the finished closure 1, in the form of a single separation layer 22, it helps to separate the sealing layer 20 from the closure body 10 when the container is first opened.

[0117] Obviously, as long as the principle of the invention is maintained, the details of construction and forms of the embodiments may vary, even to a great extent, from what is described herein purely by way of non-limiting example, without departing from the scope of the invention as defined in the appended claims.

Claims

1. A method for manufacturing a closure (1) for closing a container (100), the closure (1) comprising a closure body (10) and an inner sealing element (20) attached to the closure body (10), The method comprises the following steps: - providing a sheet material (200), the sheet material (200) comprising at least a paper layer (202) and a sealing layer (204); - removing excess portions (204B) of the sealing layer from the sheet material (200) such that the remaining portions of the sealing layer (204) form an internal sealing element (20) in the sheet material (200); - Shaping the sheet material (200) previously formed with the inner sealing element (20) by means of a shaping device (400) in order to achieve a closure body (10) with attached inner sealing element (20).

2. The method according to claim 1, wherein: The closed body has a top wall (12) and a side wall (14), an internal sealing element (20) is attached to the inner surface (12A) of the top wall (12), The method is characterized in that: - providing a sheet material (200) comprises providing the sheet material with at least one first portion (222) for forming a top wall (14) of a closure body (10) and at least one second portion (224) for forming a side wall (14) of the closure body (10); - removing an excess portion (204B) of the sealing layer (204) is performed on at least one first portion (222) of the sheet material (200), - The formed sheet material includes at least one first portion (222) of the formed sheet material (200) so as to realize the top wall (12) of the closure body (10), at least one second portion (224) of the formed sheet material (200) so as to realize the side wall (14) of the closure body (10), and arranging the sealing element (20) previously formed in the sheet material (200) at the inner surface (12A) of the top wall (12) of the finally formed closure body (10).

3. A method according to any preceding claim, wherein: Removing the excess portion (204B) of the sealing layer (204) includes: - cutting the sheet material (200) so as to achieve at least one cut (212) in the sealing layer (204), said cut (212) dividing the sealing layer (204) into the inner sealing element (20) and a surplus portion (204B), and - Peeling off the excess portion (204B) of the sealing layer (204) from the sheet material (200), while leaving the inner sealing element (20) therein.

4. The method according to claim 3, wherein: - providing a sheet material (200) comprises providing a sheet material (200) having a separation layer (206), the separation layer (206) being arranged between the paper layer (202) and the sealing layer (204); - Peeling includes peeling off the excess portion (204B) of the sealing layer (204) from the separation layer (206) of the sheet material (200).

5. A method according to any preceding claim, wherein: - providing a sheet material (200) comprises providing a web (200) of sheet material advancing and extending continuously along a working path (K); - in a first station (300) along the working path (K), removing excess portions (204B) of the sealing layer (204) from the web (200) in order to form a series of internal sealing elements (20) therein along the working path (K); - in a second station (400) downstream of the first station (300) along the working path (K), forming by means of a forming device (400) a series of closure bodies (10), each closure body (10) having attached thereto a respective one of a series of internal sealing elements (20) previously formed in the web (200); - Separating the formed closure bodies (10) from the web (200) by cutting.

6. The method according to claim 5, wherein: Removing the excess portion (204B) of the sealing layer (204) includes: - cutting the web (200) so as to achieve a series of cuts (212) in the sealing layer (204) along the working path (K), said cuts (212) dividing the sealing layer (204) into a series of internal sealing elements (20) and a surplus portion band, and - Peeling off the excess portion of the strip (204) from the sheet material (200) while leaving a series of internal sealing elements (20) therein.

7. A method according to any preceding claim, wherein: The sealing layer includes at least one of the following materials: aluminum, plastic, paper, or any combination thereof.

8. The method according to claim 4, wherein: The separation layer comprises a polymer, in particular a fossil-based and recyclable plastic or a biodegradable polymer, such as PHA, PBS, PLA or the like.

9. A closure (1) for closing a container (100), said closure being produced by a method according to any one of the preceding claims.

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