A closing means, a flexible package with a closing means, and a method for manufacturing a closing means

Abstract

The invention relates to a closing means (10) for closing an open side of a flexible package. The closing means (10) comprises a surface material blank (14) with a first permanently adhesive surface (17) on its first longitudinal edge and a second permanently adhesive surface (17) on its second longitudinal edge. A tackifier surface (16) is provided between the permanently adhesive surfaces (17, 17). The closing means (10) also comprises two cardboard strips (11, 12) glued onto the surface material blank (14) in the longitudinal direction. The first cardboard strip (11) comprises a non-adhesive surface (15) aligned with the tackifier surface (16) in the longitudinal direction. The second cardboard strip (12) is aligned with the second permanently adhesive surface (17) in the longitudinal direction. The invention also relates to a flexible package (70) provided with a closing means (70), and a method for manufacturing the closing means (10, 70).

Description

[0001] A closing means, a flexible package with a closing means, and a method for manufacturing a closing means

[0002] Field of the invention

[0003] The invention relates to a closing means for a flexible package, by which the flexible package can be closed and re-closed after being opened. The invention also relates to a flexible package provided with a closing means, as well as to a method for manufacturing a closing means.

[0004] Background of the invention

[0005] Flexible packages, such as bags, made of paper and fibre material, are conventionally closed by an adhesive area, for example with glue, by ultrasonic sealing or by heat sealing. When the package is opened, different parts of the package are separated from each other mechanically, for example by pulling the parts apart in a direction transverse to a seam or, in case of a flap, by tearing the flap off the package at the side where it has been sealed. Aluminium foil packages, in turn, can be opened, for example, by tearing off the top part of the bag. Plastic packages, such as bags of sweets, can be opened by tearing off an area of material from the top part of the bag, or by pulling the front and rear parts of the bag in opposite directions, whereby the seam opens by detaching from at least one of the two surfaces.

[0006] A problem with many conventional flexible packages is that after being opened, they can no longer be closed without a separate closing means, such as a bag clip which is made of plastic and whose counterparts are pressed against each other, or a closing strip comprising a metal wire structure, or a closing means based on the cable tie technique. In some foil or plastic packages, the upper part of the package is provided with a structure that is reseal- able by pressing, for example a so-called zipper closure based on MinigripRtechnique, that is, a groove on the first inner wall of the package and a tongue on the second inner wall. This structure is closed by pressing the tongue into the groove. However, this solution is normally used for plastic material, and it is not suitable for all types of material, for example for a paper bag, because of its poor resistance to tension. Closing means made of biodegradable plastic and based on the zipper i.e. MinigripRtechnique exist, but this material interferes with the recycling of fibres as well. Flexible packages may also comprise a re-closable adhesive surface on the inner wall of the package. In this solution, when the bag is open, the adhesive surface is unprotected and material may accumulate on it, hampering its re-closure.

[0007] Brief summary of the invention

[0008] It is an aim of the present invention to provide and present a novel closing means for a flexible bag, a flexible package provided with a closing means, as well as a method for manufacturing a closing means. The invention is characterized in what will be presented in the independent claims, and the dependent claims relate to advantageous embodiments of the invention.

[0009] The invention relates to a closing means for a flexible package, for closing an open side of the flexible package. The closing means comprises a surface material blank, wherein the surface material blank comprises a first permanently adhesive surface at its first longitudinal edge and a second permanently adhesive surface at its second longitudinal edge. A tackifier surface is provided between the permanently adhesive surfaces. The closing means also comprises two cardboard strips glued onto the surface material blank in the longitudinal direction. The first cardboard strip comprises a non-adhesive surface aligned with the tackifier surface in the longitudinal direction, and the second cardboard strip is aligned with the second permanently adhesive surface in the longitudinal direction.

[0010] In an embodiment, the non-adhesive surface consists of uncoated material of the material blank. In an embodiment, the non-adhesive surface consists of silicone or comprises silicone. In an embodiment, the material of the surface material blank is recyclable. In an embodiment, the adhesives of the permanently adhesive surfaces and the tackifier surface are the same adhesive. In an embodiment, the edge area of the first cardboard strip is a gripping area for handling the closing means. In an embodiment, the closing means comprises a fixing area on the surface of the second cardboard strip, for attaching the closing means to the flexible package. In an embodiment, the surface material blank is wider than the two adjacent cardboard strips in the width direction, wherein the width direction is perpendicular to the longitudinal direction of the closing means, and wherein the edge of the surface material blank is folded at least partly onto the first cardboard strip.

[0011] The invention also relates to a flexible package comprising a closing means according to any of the embodiments mentioned above. The closing means is attached to the outer surface of the second wall of the flexible package by means of adhesive or by a fixing surface provided on the surface of the second cardboard strip of the closing means. The tackifier surface of the closing means is against the non-adhesive surface provided on the first cardboard strip when the first cardboard strip is against the surface material blank and the flexible package is open, and against the first wall of the flexible package when the flexible package is closed by the closing means. Alternatively, the flexible package may comprise an integrated closing means, wherein the end section of the second wall of the flexible package constitutes the surface material blank for the closing means. The integrated closing means comprises a first cardboard strip and a non-adhesive surface on its surface on the side of the end section. The edge area of the end section is provided with a permanently adhesive surface for attaching the first cardboard strip to the end section. Below the permanently adhesive surface, seen from above the package, a tackifier surface is provided which is against the non-adhesive surface provided on the first cardboard strip when the first cardboard strip is against the end section, and against the first wall of the flexible package, the outer surface thereof, when the flexible package is closed by the integrated closing means.

[0012] In an embodiment, the integrated closing means also comprises a second cardboard strip, wherein the second cardboard strip is attached to the end section by a permanently adhesive surface provided below the tackifier surface, seen from above the flexible package. In an embodiment, the material of the flexible package is recyclable paper fibre, compostable or biodegradable fibre material, compostable or biodegradable film material, plastic, laminate, or aluminium foil. In an embodiment, the top section of the front wall of the flexible package is provided with a stiffening piece consisting of a glued material strip or paper tape. The invention further relates to a method for manufacturing a closing means. The method comprises at least the following steps:

[0013] - providing a roll or a blank of surface material as a surface material blank;

[0014] - providing the longitudinal edge sections of the surface material blank with a first permanently adhesive surface and a second permanently adhesive surface;

[0015] - providing a tackifier surface between the permanently adhesive surfaces; and

[0016] - gluing two cardboard strips, wherein the first cardboard strip comprises a non-adhesive surface, onto the surface material so that the non-adhesive surface of the first cardboard strip is aligned with the tackifier surface and the second cardboard strip is aligned with the second permanently adhesive surface, and so that a gap is left between the cardboard strips.

[0017] In an embodiment, the non-adhesive surface of the first cardboard strip is larger than or equal in size with the tackifier surface of the surface material blank.

[0018] Description of the drawings

[0019] In the following, the invention will be described in more detail with reference to the appended drawings, in which

[0020] Fig. 1 a shows a closing means according to an example from a first direction;

[0021] Fig. 1 b shows the closing means of Fig. 1a from the first direction, also indicating the location of a non-adhesive surface of the closing means;

[0022] Fig. 1 c shows the closing means of Fig. 1 a from a second direction;

[0023] Fig. 1 d shows the closing means of Fig. 1a from the second direction, also indicating the locations of adhesive surfaces of the closing means;

[0024] Fig. 1 e shows the closing means of Fig. 1 a from an end direction, also indicating the non-adhesive surface of the closing means; Fig. 1f shows the closing means of Fig. 1a from the end direction, showing not only the non-adhesive surface of the closing means but also the adhesive surfaces of the closing means;

[0025] Fig. 1 g shows the closing means of Fig. 1a from the first direction, also indicating a fixing surface by which the closing means can be attached to a flexible package;

[0026] Fig. 2a shows a sample closing means seen from a first direction;

[0027] Fig. 2b shows the closing means of Fig. 2a from the same first direction, also indicating the location of a non-adhesive surface of the closing means;

[0028] Fig. 2c shows the closing means of Fig. 2a from a second direction;

[0029] Fig. 2d shows the closing means of Fig. 2a from the second direction, also indicating the locations of adhesive surfaces of the closing means;

[0030] Fig. 2e shows the closing means of Fig. 2a from an end direction, showing not only the non-adhesive surface of the closing means but also the adhesive surfaces of the closing means;

[0031] Fig. 2f shows a sample closing means from an end direction, showing a non- adhesive surface of the closing means and adhesive surfaces of the closing means;

[0032] Fig. 3a shows a sample closing means seen from a first direction, also indicating the location of a non-adhesive surface of the closing means, and comprising a eurohole;

[0033] Fig. 3b shows a sample closing means seen from a first direction, also indicating the location of a non-adhesive surface of the closing means, and comprising a handle; Fig. 4a shows a sample closing means and a flexible bag in a cross-sectional side view when the closing means is attached to the flexible package and is in the open position, and the package is open;

[0034] Fig. 4b shows the closing means and the package of Fig. 4a in a cross-sectional side view when the closing means is in an intermediate state between the open position and the closed position;

[0035] Fig. 4c shows the closing means and the package of Fig. 4a in a cross-sectional side view when the closing means is in the closed position, closing the flexible package;

[0036] Fig. 4d shows a closing means not provided with a gripping area, and a package, in a cross-sectional side view when the closing means is in an intermediate state between the open position and the closed position;

[0037] Fig. 5 shows a method for manufacturing a closing means according to the invention in a flow chart;

[0038] Fig. 6 shows an end view of a sample closing means; and

[0039] Fig. 7 shows an example of a flexible package provided with an integrated closing means in a cross-sectional side view.

[0040] Detailed description of the invention

[0041] As already mentioned under Background of the invention, flexible packages, such as paper, plastic or aluminium foil packages and bags, are conventionally closed by an adhesive area, for example with glue, by ultrasonic sealing or by heat sealing. When the package is opened, different parts of the package, most commonly opposite walls, are separated from each other mechanically, for example by pulling the walls apart in a direction transverse to the seam, whereby the seam formed by the glue or other adhesive area at the top of the bag detaches from the second wall or is split. A flexible package provided with a flap is opened by detaching the flap from the wall to which it has been sealed. Flexible packages of aluminium foil or plastic are opened by tearing off a material area from the top part of the package.

[0042] A problem with many flexible packages is thus the fact that after being opened, they can no longer be closed without a separate closing means, such as a plastic or metal clip or clamp, or a closing means containing a metal wire and used by twisting or clamping the parts together. However, it is preferable to close an opened package, to ensure better preservability and cleanliness of the products, such as food, contained in the package, but also to keep the products within the package. A re-closable flexible package also increases the possibility of re-using the flexible package and reduces the need to move the products from the package, when opened, to another package for storage.

[0043] It is true that there are re-closable flexible packages provided with an adhesive surface between the walls or in a flap, for example. However, after being taken into use, the adhesive surface is unprotected and exposed to contamination when the package is open. This impairs the re-closability of the package.

[0044] Consequently, there is a need for an inexpensive, uncontaminated closing means, or closing solution, which is easy to use and which closes and recloses a flexible package in a reliable way. The closing means according to the invention is intended to close and re-close flexible packages, such as paper, plastic or aluminium foil packages and bags, as well as flexible packages made of other flexible materials, or other packages, containers and bags suitable to be closed with a closing means according to the invention. Consequently, there are no restrictions to the material of the flexible packages to be closed by the closing means according to the invention, because the closing means is suitable for use in various bags of fibre material, plastic and foil as well as, in some cases, rigid cardboard packages. The material of the closing means is recyclable and compostable. The invention will be described in more detail hereinbelow, with reference to the figures.

[0045] Figure 1 a shows a closing means 10 according to an example from a first direction which in this case is from the front or from above. The closing means 10 comprises two primary material layers. The uppermost layer consists of cardboard, and the lowermost layer consists of surface material 14 which is a so-called surface material blank whose material may be e.g. paper or may comprise paper or cellulose. The uppermost cardboard layer consists of two cardboard strips 11 , 12. The cardboard strips 11 , 12 are attached to the surface material 14 with adhesive. The cardboard strips 11 , 12 may be originally separate strips, or they can be made by cutting a single cardboard strip into two cardboard strips 11 , 12. A gap 13 may be provided between the cardboard strips 11 , 12. The width of the gap 13 may depend on the package to which the closing means 10 is intended to be attached. In the case of particularly thick package materials, the gap 13 is preferably provided to make it easier to move the closing means 10 from the open position to the closed position, and to facilitate the closing of the package. The width of the gap may be, for example, 0.1 to 1.5 mm, but also larger where necessary. On the other hand, in the case of very thin package materials, the gap 13 may not even be necessary, but the cardboard strips 11 , 12 may be in contact with each other, and the width of the gap is substantially about 0 mm.

[0046] As mentioned above, the cardboard strips 11 , 12 are glued onto the surface material 14, and the gap 13 may or may not be provided between them. In the case of Fig. 1 a, the gap 13 is provided between the strips 11 , 12, and the surface material 14 is visible through the gap 13 between the cardboard strips 11 , 12 when the closing means 10 is viewed from the front or from above. The size of the surface material 14 may be equal to the total size of the cardboard strips 11 , 12 and the gap 13, as in this example of Fig. 1 a, but it may also be smaller or larger. Broken lines at the ends of the closing means 10 indicate the directions in which the closing means 10 could extend lengthwise.

[0047] Figure 1 a also indicates the longitudinal direction of the closing means 10 with a double-headed arrow and the letter X, and the width direction with a doubleheaded arrow and the letter Y.

[0048] Likewise, Fig. 1 b shows the closing means of Fig. 1 a from the first direction, also indicating the location of a non-adhesive surface 15 of the closing means. The non-adhesive surface 15 is illustrated with broken lines, because it is an inner surface of the closing means 10 and is provided in the lower part of the cardboard strip 11. Thus, in the closed position, the non-adhesive surface 15 is against the surface material 14 in the lower part of the cardboard strip 11 , the lower part being delimited by the gap 13 of the closing means. The upper part of the cardboard strip 11 does not comprise a non-adhesive surface. The non-adhesive surface 15 may consist of, for example, silicone or a silicone- containing material provided on the cardboard strip 11. In addition to silicone, the non-adhesive surface 15 may consist of any other material to which a tackifier does not adhere permanently when the surfaces are placed against each other. Thanks to the silicone or other non-adhesive surface 15, the tackifier surface 16 cannot dry in the open position either, at least not very easily. In some cases, the non-adhesive surface 15 may also consist of uncoated material of the cardboard strip 11 .

[0049] Figure 1 c shows the closing means of Fig. 1 a from a second direction, that is, from below or from behind. From this direction, only the surface material 14 of the closing means is visible.

[0050] Figure 1 d shows the closing means of Fig. 1a from the same direction as Fig. 1 c, but Fig. 1 d also indicates the locations of the adhesive surfaces 16, 17 of the closing means 10. The surface of the surface material 14 inside the closing means 10 is provided with adhesive surfaces 16, 17; in other words, the adhesive surfaces 16, 17 remain between the surface material 14 and the cardboard strips 11 , 12, as does the non-adhesive surface 15. Two of the adhesive surfaces are permanently adhesive surfaces 17. The first one of the permanently adhesive surfaces 17 is aligned with the upper part of the first i.e. uppermost cardboard strip 11 of the closing means 10, and it is arranged to attach the upper part of the surface material 14 and the upper part of the uppermost cardboard strip 11 of the closing means 10 permanently together. Aligned with the non-adhesive surface 15 of the surface material 14, a tackifier surface 16 is provided which is easily detached from and re-attached to the non-adhesive surface 15. Below the second cardboard strip 12 in the surface material 14, a second permanently adhesive surface 17 is provided which attaches the second cardboard strip 12 and the surface material 14 to each other. The upper part of the surface material 14 and the upper part of the first cardboard strip, glued together, provide the closing means 10 with a gripping area, by which a user grips the closing means 10 when changing the closing means 10, fastened to the flexible package, from closed to open position, or vice versa. Figure 1 e shows the closing means 10 of Fig. 1 a in a cross-sectional end view, that is, from an end direction, and also indicates the position of the the nonadhesive surface 15 of the closing means 10 between the cardboard strips 11 , 12 and the surface material 14, within the closing means 10. The end is perpendicular to the length of the closing means 10.

[0051] Figure 1 f shows the closing means 10 of Fig. 1 a in a cross-sectional view from the end direction and shows not only the non-adhesive surface 15 of the closing means 10 but also the adhesive surfaces 16, 17 of the closing means between the cardboard strips 11 , 12 and the surface material 14, within the closing means 10. The tackifier surface 16 and the non-adhesive surface 15 are aligned, that is, on top of each other, as already mentioned in connection with Fig. 1 d.

[0052] Figure 1 g shows the closing means of Fig. 1a from the first direction, also indicating the fixing surface 18 on the outer surface of the second cardboard strip 12, by which fixing surface 18 the closing means can be attached to a flexible package. The fixing surface 18 can be provided on the closing means 10 right before it is attached to the package, or it can be provided in the closing means 10 already at the manufacturing stage and protected by a removable protective paper up until the moment of fixing. The fixing surface 18 may consist of any permanent adhesive suitable for the purpose, and it may be a continuous area or consist of separate adhesive areas or one or more adhesive strips.

[0053] In connection with closing means according to the invention, the term “surface material” also comprises terms such as “surface material blank”, “surface paper”, “base paper”, “release paper”, or “release surface”, and it refers to a bio-based film material made of paper or comprising cellulose or paper, comprising at least two areas of permanently adhesive surfaces, and at least one tackifier surface extending between these in the longitudinal direction of the closing means. The paper may be made of wood, hemp, rice, straw, cotton. The surface material is normally relatively tough material so that it can withstand opening many times. If it is desired that the closing means is opened slowly by pulling, it is normally made of a thin, or relatively thin, and flexible material. If the closing means opens in a more hinge-like manner, then the surface material is often made of a thicker material. The surface material may be, for example, tape made of crepe paper.

[0054] The cardboard strips of the closing means may be called, for example, “backing material”. Thus, the backing material may be, for example, cardboard, as mentioned above, but also, for example, paper, such as film material comprising thick strips of paper or cellulose. The surface material and the backing material of the closing means are not detached from each other over their whole width but only for the narrow strip / section of the closing means, in which detaching section the surface material comprises the tackifier and the backing material comprises the re-detachable non-adhesive surface, wherein these two surfaces can be re-attached to each other over and over again. The first cardboard strip may also be called the first backing material strip, and the second cardboard strip may also be called the second backing material strip. The term “strip” refers to a piece of material having a length greater than a width, and it may also be called a ribbon or a slip. The strip normally consists of a flexible material.

[0055] Figure 2a shows another sample closing means 20 seen from a first direction, that is, from above or from the top. This closing means 20 corresponds to the closing means of Figs. 1 a to 1 g in other respects, but in the closing means 20 of Fig. 2a, a part is missing from the upper section of the first cardboard strip 21. In this closing means 20, the first permanently adhesive surface 27 attaches the upper parts of the surface material 24 and the first cardboard strip 21 together in a small area only, for the purpose of only attaching the surface material 24 and the first cardboard strip 21 to each other, not to provide the closing means 20 with a gripping area where a user could easily change the closing means attached to the flexible package from closed to open position, or vice versa. Surface material 24 is visible through the gap 23 between the first and second cardboard strips 21 , 22.

[0056] Figure 2b shows the closing means 20 of Fig. 2a from the same first direction, also indicating the location of the non-adhesive surface 25 of the closing means. The non-adhesive surface 25 is the inner surface of the closing means 20 and is provided in the lower part of the first cardboard strip 21. The non- adhesive surface may consist of, for example, silicone or another non-stick material.

[0057] Figure 2c shows the closing means 20 of Fig. 2a from a second direction, that is, from below or from the rear. From this direction, only the surface material 24 of the closing means 20 is visible.

[0058] Figure 2d shows the closing means of Fig. 2a from the same direction as Fig. 2c, but Fig. 2d also indicates the locations of the adhesive surfaces 26, 27 of the closing means 20. The adhesive surfaces 26, 27 are between the surface material 24 and the cardboard strips 21 , 22, as is the non-adhesive surface 25. Two of the adhesive surfaces are permanently adhesive surfaces 27. The first one of the permanently adhesive surfaces 27 is at the upper part of the first i.e. uppermost cardboard strip 11 of the closing means 20, and it is arranged to attach the upper part of the surface material 24 and the upper part of the uppermost cardboard strip 21 of the closing means 20 permanently together. In this closing means 20, that fixing area is small, whereby no gripping section or a very narrow gripping section is formed. A tackifier surface 26 is provided at the location of the non-adhesive surface 25 of the surface material 24. The tackifier surface 26 is equal in size with the non-adhesive surface, or smaller. Below the second cardboard strip 22 in the surface material 24, a second permanently adhesive surface 27 is provided which attaches the second cardboard strip 22 and the lower part of the surface material 24 together.

[0059] Figure 2e shows a cross-sectional view of the closing means 20 of Fig. 2a from an end direction, and indicates not only the non-adhesive surface 25 of the closing means 20 but also the adhesive surfaces 26, 27 of the closing means between the cardboard surfaces 21 , 22 and the surface material 24, within the closing means 20.

[0060] Figure 2f shows an alternative implementation for the solution of Fig. 2a, seen from the end direction of the closing means 28, as in Fig. 2e. In the solution of Fig. 2f, the surface material 24 is wider than the total width of the cardboard strips 21 , 22. This width of the surface material 24, exceeding the total width of the cardboard strips 21 , 22, is folded over the edge of the first cardboard strip 21 and attached with adhesive to the second surface of the first cardboard strip 21 , which is the outer surface of the closing means 28, whereby it is glued at least partly at the location of the non-adhesive surface 25 of the cardboard strip 21 but on the opposite side of the cardboard strip 21. This solution may further comprise a gripping area, but if it is necessary to make the closing means 28 as narrow as possible, the gripping area may also be totally omitted. If a gripping area is not included in the solution or it is very narrow, the closing means 28 is preferably handled from the cardboard strip 21 whose first surface, i.e. inner surface, is thus provided with the non-adhesive surface 25, and whose second surface, i.e. outer surface, is provided with the surface material 24 glued onto it.

[0061] Figure 3a shows a sample closing means 30 seen from a first direction, also indicating the location of a non-adhesive surface 35 of the closing means 30 as well as a gap 33 between a first cardboard strip 31 and a second cardboard strip 21. Surface material 34 of the closing means is visible through the gap 33. The closing means 30 comprises a eurohole 36 for hanging, in the upper part of the closing means 30.

[0062] Figure 3b shows a sample closing means 39 seen from a first direction, also indicating the location of a non-adhesive surface 35 within the closing means 39 as well as a gap 33 between a first cardboard strip 31 and a second cardboard strip 32. Surface material 34 of the closing means is visible through the gap 33. The closing means 39 comprises a handle 37 for carrying, in the upper part of the closing means 39.

[0063] Figure 4a shows a sample closing means 40 and a flexible package 47 in a cross-sectional side view when the closing means 40 is attached to the upper part of the flexible package 47 and the closing means 40 is in the open position and the package 47 is open. The closing means comprises a first cardboard strip 41 and a second cardboard strip 42, whose surface placed against the flexible package 47 is provided with a fixing surface 42’ by which the closing means 40 is fixed to the upper part of the package 47. A gap 43 is provided between the cardboard strips 41 , 42. The fixing surface 42’ may be provided with a release paper which is removed before the closing means 40 is attached to the flexible package 47. The release paper is not shown in Fig. 4a because the closing means 40 is already fixed to the flexible package 47. The second surface of the cardboard strip 42 is provided with surface material 44. The fixing surface 42’ and the surface material 44 are arranged on opposite sides, i.e. surfaces, of the cardboard strip 42. The open side 48 of the package 47 is facing up. The upper part of the front wall of the package 47 is provided with a stiffening piece 46 for the package 47, whereby the package 47 is stiffened; in other words, it is a stiffened flexible package. Particularly if the package 47 is made of thin material, the stiffening piece 46 facilitates its handling and / or maintaining its open position. The stiffening piece 46 is an optional piece of the package 47.

[0064] Figure 4b shows the closing means 40 and the package 47 of Fig. 4a in a cross-sectional side view as well. The closing means 40 is in an intermediate state between the open position and the closed position, wherein closing of the package 47 has been started by removing the non-adhesive surface 45 from the surface of the tackifier 44’ on the surface material 44 by using the gripping area 49 and / or by bending the gripping area 49 downwards. The gripping area 49 is the edge area of the first cardboard strip 41 .

[0065] Figure 4c again shows the closing means 40 and the package 47 of Fig. 4a in a cross-sectional side view when the closing means 40 is in the closed position and closes the flexible package 47. The package 47 has been closed by the closing means 40 by using the gripping area 49 to guide the tackifier surface 44’ of the surface material 44 against the first wall of the package 47, over the open side 48 of the package 47. The closing means 40 has been attached to the second wall of the package 47.

[0066] By the tackifier surface 44’, the closing means 40 closes the flexible package 47 in a re-openable way, and when the closing means 40 is closed, the tackifier surface 44’ is against the package 47, whereas in the open position, the tackifier surface 44’ of the closing means 40 is against the non-adhesive surface 45 of the cardboard strip 41 and protected from becoming contaminated. The gripping area 49 is, so to say, a gripping tab making it really easy to close and open the package 47. In practice, pressing down the gripping tab will close the bag, i.e. the package 47, by guiding the tackifier surface 44’ against the front wall of the package 47, and lifting it up will open the package and place the tackifier surface 44’ against the non-adhesive surface 45. Figure 4d shows the closing means 40’ and the package 47 in a cross-sectional side view. In other respects, the closing means 40’ corresponds to the closing means 40 of Fig. 4a but it does not have the gripping area 49; in other words, it is devoid of the gripping area 49’, or the gripping area 49’ is very narrow or non-existent. Consequently, the closing means 40’ structurally corresponds to the closing means 28 of Fig. 2f, and the section of the surface material 44” that is wider than the closing means 40’ is glued onto the outer surface of the first cardboard strip 4T, partly in alignment with the non-adhe- sive surface 45’ provided on the second surface of the first cardboard strip 4T.

[0067] Of flexible packages which can be closed by a closing means according to the invention, paper packages are packages made of paper or combinations, i.e. laminates, of paper and other materials. The paper used in flexible packages is preferably recyclable, compostable or biodegradable. Although a paper package is normally made of wood-based or other vegetable fibres, the material may also contain other fibres.

[0068] A laminate for a paper package may comprise two or more material layers, one of which typically consists of paper. In other words, the laminate may comprise, for example, one layer of paper and another layer of another material, or, for example, three different layers, of which one layer comprises paper and two other layers comprise other materials. One or more layers of the laminate may comprise fibre materials. As the fibre material, it is possible to use paper or other wood or pulp based fibre materials, such as wood fibre or non-woven materials. Preferably, the fibre material used in the laminate is recyclable, and if it is not recyclable, it is preferably at least biodegradable or compostable. One or more layers of the laminate may also comprise wood or pulp based materials other than fibre materials, such as film materials. Cellulose film can also be used as a film material, and plastics can be used as layers in the laminate. The plastic used in the laminate may be selected from the group of polyethylene (PE), polypropylene (PP), polyethylene terephtalate (PET), biobased and / or biodegradable plastics, such as polycaprolactone (PLC), polyvinyl alcohol (PVOH), polylactide (PLA), as well as combinations of these. Preferably, the paper-plastic laminate comprises paper and biodegradable plastic, which guarantees compostability of the package, particularly advantageously paper and polylactide (PLA).

[0069] Plastic packages, in turn, may consist of, for example, polyethylene (LDPE), polypropylene (PP) film, or another plastic package material suitable for packing the material in question, preferably recyclable plastic packaging material. Aluminium foil packages are normally aluminium-plastic composite vacuum- packed bags.

[0070] The adhesive surfaces of the closing means can be provided in the blank as an adhesive area, stripe or stripes of one or more different glues. In this context, providing means applying i.e. gluing adhesive on the surface of the blank. The adhesive used may be any suitable adhesive that is preferably made of any suitable glue. The adhesive may be selected by considering or not considering the requirements of recyclability and compostability. Furthermore, the adhesive may be selected depending on the product packed in the package, whether it is food or another product. For attaching the closing means to paper and cardboard packages, hot-setting adhesive is primarily used, but liquid glue or tackifier is feasible as well.

[0071] Thanks to the cardboard strips, the closing means has a rigid structure, and the gap between them, together with the surface material, acts as a hinge. A closing means with a rigid structure is easier to open and close than a readily flexible or bendable closing means. Moreover, even if the material of the package were flexible in other respects, the upper part of the front wall (first wall) of the package can be stiffened with a separate material layer or paper tape or the like while the closing means is attached to the rear wall (second wall).

[0072] As such, the closing means is useful for closing packages to be opened in different ways, such as packages to be opened by tearing from the side or from above, coffee packages or the like, or perforated bags. It is also suitable for closing flexible packages which have not been closed by sealing or gluing, such as conventional paper bags, plastic bags etc. without a seam at the top.

[0073] The most advantageous way to manufacture and provide the closing means to a manufacturer of flexible packages is, in many cases, the form of a band coiled in a roll. In the form of a band, the closing means can be attached to the package material with adhesive at the stage when the package material is discharged from a roll to a machine for folding up bags, by means of an adhesive that is sufficiently strong for the purpose. The closing means may also be attached to a finished flexible package or cardboard box first after the flexible package or cardboard box is complete, i.e. in its final shape and possibly even filled. Closing means can also be delivered cut-to-length.

[0074] Consequently, in the closing means according to the invention, no release strips are needed to protect the adhesive surfaces, because the tackifier surface is always either against the non-adhesive surface of the closing means, in the open position, or against the wall of the package, in the closed position. However, if a fixing surface (reference 18 in Fig. 1g) is provided on the second cardboard strip of the closing means, it is preferably provided with a release strip until it is attached to the package. Thus, the closing means can be provided with a fixing surface if the closing means is intended to be fastened to the package by the user.

[0075] The invention also relates to a flexible package comprising a closing means according to the invention, that is, a flexible package with a closing means. One such flexible package with a closing means is a paper package, for example a recyclable paper package, in which the seam closing the package is provided with a fibre rip stopper. The paper package comprises at least a first package wall and a second package wall, as well as an adhesive area between the first wall and the second wall. The adhesive area forms the seam closing the package.

[0076] The closing means according to the invention can be made by a method comprising at least the following steps:

[0077] - providing a material roll or blank of surface material as a surface material blank;

[0078] - providing the longitudinal edge areas of the surface material blank with a first permanently adhesive surface and a second permanently adhesive surface;

[0079] - providing a tackifier surface between the permanently adhesive glue surfaces; and - gluing two cardboard strips, i.e. backing material strips, the first cardboard strip comprising a non-adhesive surface, onto the surface material so that the non-adhesive surface of the first cardboard strip is aligned with the tackifier surface of equal or smaller size, and the second cardboard strip is aligned with the second permanently adhesive surface, and so that a gap is left between the cardboard strips.

[0080] The flexible package with the closing means can be made by using machines, equipment and methods typically used in the industry. Edge areas of the surface material refer to the longitudinal edges of the elongated surface material blank, not the ends. The second cardboard strip is at least equal in size with the second permanently adhesive surface. It is possible, in the method, that the first and second cardboard strips are cut into two different cardboard strips if they are not separate strips already. In the closing means, the cardboard i.e. backing material strips and the surface material blank are equal in length.

[0081] Figure 5 shows a flow chart of a method 50 for manufacturing a closing means according to the invention. The method 50 comprises at least the following steps whose sequence may vary and which method 50 may comprise additional steps. A method step 51 comprises providing a material roll or blank of surface material as a surface material blank. A method step 52 comprises providing the longitudinal edge areas of the surface material blank with a first permanently adhesive surface and a second permanently adhesive surface. A method step 53 comprises providing a tackifier surface between the permanently adhesive surfaces, in the longitudinal direction of the closing means. A method step 54 comprises gluing two cardboard strips, the first cardboard strip comprising a non-adhesive surface, onto the surface material so that the non- adhesive surface of the first cardboard strip is aligned with a tackifier surface of equal or smaller size, and the second cardboard strip is aligned with the second permanently adhesive surface, and so that a gap is left between the cardboard strips.

[0082] The closing means may be equal in length with the open side of the package to which the closing means is to be fastened, but it may also be shorter or longer. The cardboard strips may be equal or different in width. The width refers to the direction perpendicular to the length of the elongated closing means. The area of the surface material under the cardboard strips is not always equal to the total area of the cardboard strips and the gap. The area of the surface material may be smaller but sufficient for the cardboard strips to remain attached to it with the permanently adhesive surfaces (for example, reference 17 in Fig. 1 d). The area of the surface material may also be larger than the total area of the cardboard strips and the gap, when the section of the surface material exceeding the above-mentioned total area is folded over the top edge of the first cardboard strip and glued by the adhesive surface (reference 27 in Fig. 2f) onto the second surface of the cardboard strip. Any suitable adhesive can be used on the adhesive surfaces, i.e. the permanently adhesive surfaces and the tackifier surface (e.g. references 17, 16 in Fig. 1 d). In some cases, for example in the case of porous surface material, the adhesives may be the same adhesive. For better bonding of the closing means to the package, the adhesive used on the permanently adhesive surfaces often has a higher bond strength than the adhesive used on the tackifier surface.

[0083] An advantage of the closing means is an increase in printable surface area. Although the closing means covers part of the package, it provides more printable surface area for the package comprising the closing means. The user may pay more attention to the top of the package than the other parts of the package, because it comprises, for example, the open mouth of the bag. One could also presume that one’s eyes would be caught particularly by the moving and movable closing means according to the invention at the top of the package, and simultaneously by the printing on it.

[0084] It should also be noted that in some cases the closing means may be a direct extension to the material of the flexible package (an extension of the rear wall, i.e. the second wall), that is, a part of the flexible package (see Fig. 7). The material of the flexible package is used as the surface material of the closing means. In this case, the closing means does not need a separate fixing surface, or it is not separately attached to the package at the location of the second cardboard strip. Most often, the second cardboard strip and the surface material in its location are omitted, compared with a separate closing means.

[0085] Figure 6 shows an end view of a sample closing means 60. In this closing means 60, the tackifier surface 66 of the surface material 64 is formed by using permanent adhesive 647 on the surface material 64 to attach an additional cardboard strip or an additional paper strip 641 , whereby the opposite surface of the additional cardboard strip 641 , facing the first cardboard strip, is provided with a tackifier surface 66. The closing means 60 is used in a way similar to the other closing means according to the application, but with the difference that when the closing means 60 is closed and opened, the tackifier surface 66 moves as an almost non-bending planar surface, while the non-reinforced / non- adhesive sections of the surface material, i.e. those surface material areas which do not comprise the additional cardboard strip 641 , act as hinge surfaces. Thus, Fig. 6 shows a first cardboard strip indicated with reference numeral 61 , a second cardboard strip indicated with reference numeral 62, and surface material which is indicated with reference numeral 64 and to which an additional cardboard strip 641 is attached with permanent adhesive 647. A non-adhesive surface 65 is provided under the first cardboard strip 61 , i.e. on its lower / inner surface, and an adhesive surface 66 is provided on the other surface of the additional cardboard strip 651 , not facing the surface material 64. The permanently adhesive surfaces between the first cardboard strip 61 or the second cardboard strip 62 and the surface material 64 are indicated with reference numerals 67.

[0086] Figure 7 shows a sample of a flexible package 77 with an integrated closing means 70 in a cross-sectional side view when the package 77 is open. The open side 78 of the package 77 is facing up. An integrated closing means 70 is a direct extension of the rear wall, i.e. the second wall, of the flexible package 77, in other words, a part of the flexible package 77. The end section 74 of the second wall replaces the surface material blank mentioned in the other examples of the closing means. The closing means 70 comprises a first cardboard strip 71 , a second cardboard strip 72, and gap 73, as well as a non-adhesive surface 75 on the lower surface of the first cardboard strip 71 , i.e. the inner surface of the closing means 70. The gap 73 is provided between the first and second cardboard surfaces 71 , 72. The closing means 70 can also be implemented without the second cardboard strip 72 and / or the gap 73. Furthermore, the integrated closing means 70 does not need to be fixed to the flexible package by a fixing surface, which is why a fixing surface is not provided in this solution. The first cardboard strip 71 is attached to an end section 74 with permanently adhesive glue provided on the surface of the end section, on the side of the inner surface of the package. In this figure, the closing means 70 is in an intermediate state between the open position and the closed position, and closing of the open package 77 has been started by removing the non-adhe- sive surface 75 from a tackifier surface 74’ provided in the end section 74. The non-adhesive surface 75 and the tackifier surface 74’ are aligned when the first cardboard strip 71 of the closing means 70 is against the end section 74; in other words, the closing means 70 does not close the package 77, and closing of the package has not been started. The second cardboard strip 72 is attached to the end section 74, underneath the tackifier surface 74’, seen from the top of the package 77, i.e. from the direction of the open side 78, with permanently adhesive glue provided next to the tackifier surface 74’ in the end section 74. In this figure, the second cardboard strip 72 is attached to the second wall of the package, on the inner surface of the package 77, but as an alternative, it can be attached to the same location of the end section 74 but on its outer surface. The second cardboard strip 72 increases the rigidity of the mouth of the flexible package 77; however, it is not a necessary part of the integrated closing means 70 but it can be replaced by a part of an end section of the second i.e. rear wall of the flexible package 77.

[0087] In an integrated closing means 70 similar to that shown in Fig. 7, the tackifier surface 74’ of the end section 74 can be, alternatively, provided on an additional cardboard strip (see, for example, reference 641 in Fig. 6) attached by a permanently adhesive surface (see, for example, reference 647 in Fig. 6) to the surface of the end section 74 on the inside of the package 77. The additional cardboard strip is attached to the end section 74, in such a location between the end section 74 and the first cardboard strip 71 that the tackifier surface and the non-adhesive surface 74 are facing each other, i.e. aligned, when the closing means 70 is in the closed position. Thanks to the additional cardboard strip, the tackifier surface 74’ of the closing means moves as an easily controllable planar surface when the closing means is opened and closed, and it also makes the mouth of the package 77 more rigid. The second cardboard strip 72 may be included in the closing means 70, or it may be eliminated, whereby the additional cardboard strip replaces the second cardboard strip, i.e. acts as the second cardboard strip according to the invention. When the additional cardboard strip replaces the second cardboard strip in the integrated closing means, the structure is simpler and has a lower price. An even simpler and less expensive integrated closing means is one where not only the second cardboard strip but also the additional cardboard strip is omitted from the structure. This kind of a structure is often the most advantageous integrated closing means.

[0088] When the closing means comprises a eurohole (see, for example, reference 36 in Fig. 3a) or a handle (see, for example, reference 37 in Fig. 3b), the structure can be strengthened by attaching a separate material strip of e.g. cardboard by means of a permanent adhesive surface between the surface material and the first cardboard material, in the section of the closing means above the tackifier surface and the non-adhesive surface, i.e. the area of the eurohole and the handle. This reinforcing material strip is thus fastened by both of its surfaces to the closing means: by the first surface to the surface material and by the second surface to the first cardboard strip.

[0089] For using the closing means 70, the gripping area 79 is bent downwards. The gripping area 79 is the edge area of the cardboard strip 71 . However, the closing means 70 could also be without a gripping area, like the closing means 28 of Fig. 2f.

[0090] The upper part of the front wall of the package 77 is provided with a stiffening piece 76 for the package 77, by which the package 77 is reinforced; that is, it is a reinforced flexible package. Particularly if the package 77 is made of thin material, the stiffening piece 76 facilitates its handling and / or maintaining its open position. The stiffening piece 76 is an optional piece of the package 77.

[0091] It should be noted that in some cases it is possible to make part or whole of the closing means of plastic as well.

[0092] The above described closing means have the advantage of being easy to use as they are easy to open particularly by using the gripping area. The tackifier surface of the closing means moves, in a way, snapping from the open position to close the package, and vice versa. Another advantage is the material which can be selected relatively freely to be recyclable or non-recyclable. The features described and the examples mentioned in the application are freely combinable and interchangeable, except if the application particularly states that the embodiments or features are not interchangeable. The closing means according to the invention can be used to close not only flexible pack- ages but also cardboard packages or packed larger products such as bars of chocolate or the like, or any packages which can be closed by the closing means presented in the embodiments / examples. The exemplary features described in connection with the different examples can be used with any other embodiment even if this were not mentioned separately.

Claims

Claims:1 . A closing means for closing an open side of a flexible package, wherein the closing means (10) comprises a surface material blank (14), wherein the surface material blank (14) comprises a first permanently adhesive surface (17) on its first longitudinal edge and a second permanently adhesive surface (17) on its second longitudinal edge, and a tackifier surface (16) between said permanently adhesive surfaces, characterized in that the surface material blank(14) also comprises two cardboard strips (11 , 12) glued onto the surface material blank (14) in the longitudinal direction, wherein the first cardboard strip (11 ) comprises a non-adhesive surface (15) which is aligned with the tackifier surface (16) in the longitudinal direction, and the second cardboard strip (12) is aligned with the second permanently adhesive surface (17) in the longitudinal direction.

2. The closing means according to claim 1 , wherein the non-adhesive surface(15) consists of uncoated material of the material blank.

3. The closing means according to claim 1 , wherein the non-adhesive surface(15) consists of silicone or comprises silicone.

4. The closing means according to any of the claims 1 to 3, wherein the material of the surface material blank (14) is recyclable.

5. The closing means according to any of the claims 1 to 4, wherein the adhesives of the permanently adhesive surfaces (17, 17) and the tackifier surface(16) are the same adhesive.

6. The closing means according to any of the claims 1 to 5, wherein the edge area of the first cardboard strip (11 ) is a gripping area for handling the closing means.

7. The closing means according to any of the claims 1 to 6, comprising a fixing area on the surface of the second cardboard strip (12), for fastening the closing means (10) to a flexible package.

8. The closing means according to any of the claims 1 to 7, wherein the surface material blank (14) is wider in the width direction than the two adjacent cardboard strips (11 , 12), wherein the width direction is transverse to the longitudinal direction of the closing means, and wherein the edge of the surface material blank (14) is folded at least partly over the first cardboard strip (11 ).

9. A flexible package comprising a closing means (40) according to any of the claims 1 to 8, wherein the closing means (40) is fixed to the outer surface of the second wall of the flexible package (47) with adhesive or with a fixing surface (42’) provided on the surface of the second cardboard strip (42) of the closing means (40), and wherein the tackifier surface (44’) of the closing means (40) is against the non-adhesive surface (45) provided on the first cardboard strip (41 ) when the first cardboard strip (41 ) is against the surface material blank (44), and against the first wall of the flexible package (47) when the flexible package (47) is closed with the closing means (40), or the flexible package (77) comprises an integrated closing means (70), wherein the end section (74) of the second wall of the flexible package (74) constitutes the surface material blank for the closing means (70), and wherein the integrated closing means (70) comprises a first cardboard strip (71 ) and a non- adhesive surface (75) on its surface on the side of the end section, wherein the edge area of the end section is provided with a permanently adhesive surface for attaching the first cardboard strip (71) to the end section (74), and a tackifier surface (74’) is provided under the permanently adhesive surface, seen from above the package, wherein the tackifier surface (74’) is against the non-adhesive surface (75) provided on the first cardboard strip (71 ) when the first cardboard strip (71 ) is against the end surface (74), and against the first wall of the flexible package (77) when the flexible package (77) is closed with the integrated closing means (70).

10. The flexible package according to claim 9, wherein the integrated closing means (70) further comprises a second cardboard strip (72), the second cardboard strip (72) being attached to the end section (74), seen from above the flexible package (77), by a permanently adhesive surface provided underneath the tackifier surface (74’).

11. The flexible package according to claim 9 or 10, wherein the material of the flexible package (77) is recyclable paper fibre, compostable or biodegradable fibre material, compostable or biodegradable film material, plastic, laminate, or aluminium foil.

12. The flexible package according to any of the preceding claims 9 to 11 , wherein the inner or outer surface of the top section of the front wall of the flexible package (77) is provided with a stiffening piece (76) for the package, consisting of a glued material strip or paper tape.

13. A method for manufacturing a closing means, the method comprising at least the following steps:- providing a roll or a blank of surface material as a surface material blank (51 );- providing the longitudinal edge sections of the surface material blank with a first permanently adhesive surface and a second permanently adhesive surface (52); and- providing a tackifier surface (53) between the permanently adhesive surfaces; characterized in that the method further comprises the following step:- gluing two cardboard strips, the first cardboard strip comprising a nonadhesive surface, onto the surface material so that the non-adhesive surface of the first cardboard strip is aligned with the tackifier surface and the second cardboard strip is aligned with the second permanently adhesive surface, and so that a gap (54) is left between the cardboard strips.

14. The method according to claim 13 for manufacturing a closing means, wherein the non-adhesive surface of the first cardboard strip is larger than or equal in size with the tackifier surface of the surface material blank.

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