Reclosable Cover for a Hollow Object and Method for Making Same

Abstract

Reclosable cover (100) for a hollow object (200), wherein the cover comprises a base layer (BL), a carrier layer (DL) and an adhesive layer (LL).The base layer has a first base layer cutting line (B1). The carrier layer has a first carrier layer cutting line (D1) at a first distance (d1) from the first base layer cutting line (B1) to provide a first adhesive zone (k1) which is formed to adhere the cover to the hollow object (200).

The base layer has a second base layer cutting line (B2) at a second distance (d2) from the first carrier layer cutting line (D1) to form a closing member (SL).The carrier layer has a second carrier layer cutting line (D2) at a third distance (d3) from the second base layer cutting line (B2) to provide a re-adhesive zone (k2) between the second carrier layer cutting line (D2) and the second base layer cutting line (B2).

Claims

1. Reclosable cover (100) for a hollow object (200), wherein the cover comprises: a base layer (BL), wherein a rear side (110) of the base layer is provided with a carrier layer (DL) and wherein an adhesive layer (LL) is present between the base layer and the carrier layer, wherein the base layer has a first base layer cutting line (B1) to form a peripheral edge of the cover, wherein the carrier layer has a first carrier layer cutting line (D1), lying substantially inside contours of and at a first distance (d1) from the first base layer cutting line (B1), to provide a first adhesive zone (k1) when a carrier layer part (DD) outside the first carrier layer cutting line is removed, wherein the first adhesive zone (k1) is formed to adhere the cover to the hollow object (200); wherein the base layer has a second base layer cutting line (B2), lying substantially inside the contours of and at a second distance (d2) from the first carrier layer cutting line (D1), to form a closing member (SL), and wherein the carrier layer has a second carrier layer cutting line (D2), lying substantially inside contours of and at a third distance (d3) from the second base layer cutting line (B2), to provide a re-adhesive zone (k2) between the second carrier layer cutting line (D2) and the second base layer cutting line (B2).

2. Reclosable cover according to claim 1, wherein the first distance (d1) is discontinuous over at least a segment of the first carrier layer cutting line (D1), this segment having a segment length which amounts to at least 20% of an overall length of the first carrier layer cutting line (D1).

3. Reclosable cover according to claim 2, wherein the first carrier layer cutting line (D1) is non-linear at the position of the segment.

4. Reclosable cover according to claim 2, wherein the segment follows a path (T) which has a repetitive pattern.

5. Reclosable cover according to claim 1, wherein the first carrier layer cutting line (D1) extends along substantially the whole first base layer cutting line (B1).

6. Reclosable cover according to claim 1, wherein more than 40%, preferably more than 50% of the second base layer cutting line (B2) is situated in edge zones of the cover.

7. Reclosable cover according to claim 1, wherein the second base layer cutting line (B2) and/or the second carrier layer cutting line (D2) is substantially C- or U-shaped.

8. Reclosable cover according to claim 1, wherein the base layer (BL) is manufactured substantially from a first material (m1) and the carrier layer (DL) is manufactured substantially from a second material (m2), and wherein the first material (m1) and the second material (m2) have substantially the same melting temperature and/or density.

9. Reclosable cover according to claim 1, wherein the adhesive layer (LL) comprises a pressure-sensitive adhesive.

10. Reclosable cover according to claim 1, wherein the cover is provided with one or more ventilation holes (180) lying substantially inside the contours of the second carrier layer cutting line (D2).

11. Reclosable cover according to claim 10, wherein the ventilation holes extend through the base layer, the adhesive layer and the carrier layer.

12. Reclosable cover according to claim 1, wherein the closing member (SL) is further provided with an opening tab (OL) which is formed in that the first base layer cutting line (B1) and the second base layer cutting line (B2) overlap at the position of the opening tab (OL).

13. Reclosable cover according to claim 12, wherein the opening tab (OL) is provided with a carrier layer portion (700) which is surrounded by a third carrier layer cutting line (D3) situated at least partially outside the contours of the first carrier layer cutting line (D1).

14. Hollow object comprising at least one reclosable cover according to claim 1.

15. Hollow object according to the foregoing claim, wherein the reclosable cover is fixed directly on an upper surface of the hollow object via the first adhesive zone.

16. Method for manufacturing a reclosable cover (100), comprising the steps of: providing a base layer (BL) and a carrier layer (DL) and an adhesive layer (LL) between the base layer and the carrier layer; providing a first base layer cutting line (B1) on the base layer to form a peripheral edge of the cover; providing a first carrier layer cutting line (D1) on the carrier layer, substantially inside the contours of and at a first distance (d1) from the first base layer cutting line (B1), to provide a first adhesive zone (k1); providing a second base layer cutting line (B2) on the base layer, substantially inside the contours of and at a second distance (d2) from the first carrier layer cutting line (D1), to form a closing member (SL); and providing a second carrier layer cutting line (D2) on the carrier layer, substantially inside the contours of and at a third distance (d3) from the second base layer cutting line (B2), to provide a re-adhesive zone (k2) between the second carrier layer cutting line (D2) and the second base layer cutting line (B2).

17. Method according to claim 16, further comprising: placing the reclosable cover on a hollow object by removing a first carrier layer part outside the first carrier layer cutting line.

Description

[0019] The invention will now be described in more detail with reference to the accompanying drawings shown in the figures, which show some but not all embodiments of the invention. The invention can be embodied in many different ways and should not be deemed as being limited only to the embodiments described here.

[0020] FIG. 1 is a schematic representation of a top view of an embodiment of a reclosable cover arranged on top of a hollow object.

[0021] FIG. 2A is the cross-section through section line IV shown in FIG. 1.

[0022] FIG. 2B is the cross-section through section line III shown in FIG. 1.

[0023] FIG. 3 is a detail view of the cover shown in FIG. 2B.

[0024] FIG. 4 is a schematic representation of a cross-section of a view of a reclosable cover and hollow object.

[0025] FIG. 5 is a schematic representation of a top view of an embodiment of a reclosable cover arranged on top of a hollow object and having an opening tab.

[0026] FIG. 6 is the cross-section through the section line VI shown in FIG. 5.

[0027] FIG. 1 shows a top view of one of the possible embodiments of a reclosable cover according to the invention. This reclosable cover (100) is arranged on top of a hollow object (200), such as for instance a packaging container. The upper surface (Ad1) of the packaging container is shown by the broken lines (210) and (220) which are representative of respectively the outer edge and inner edge of the upper surface (Ad2) of the packaging container (200). The reclosable cover (100) has a base layer with a first base layer cutting line (B1) and a second base layer cutting line (B2), which are shown in full lines. The reclosable cover (100) further has a carrier layer (DL) with a first carrier layer cutting line (D1) and a second carrier layer cutting line (D2). The base and carrier layer cutting line (B2) and (D2) create a closing member SL. The second carrier layer cutting line is situated substantially along the edge zones of the cover (100). In FIG. 1 the closing member (SL) is partially opened along the upper right corner. An opening (150) is thus formed so that a substance (250), for instance a strawberry, located in the hollow object is made accessible. The skilled person will appreciate that many types of substance can be packaged in the hollow object.

[0028] The cutting lines are situated substantially largely in the order, as seen from the peripheral edge of the cover inward: [0029] first base layer cutting line; [0030] first carrier layer cutting line; [0031] second base layer cutting line; and [0032] second carrier layer cutting line.

[0033] In other words, the first carrier layer cutting line will be situated substantially inside the contours of the first base layer cutting line. The second base layer cutting line will also be situated substantially inside the contours of the first carrier layer cutting line. The second carrier layer cutting line will further be situated substantially inside the contours of the second base layer cutting line. The term substantially inside the contours indicates at least 50% of the cutting line, more preferably at least 70% of the cutting line, most preferably at least 90% of the cutting line. It will be apparent here that the proportion and relative position of the cutting lines can differ, for instance at the closing tab described below, without having an adverse effect on functionality and overall operation.

[0034] A first adhesive zone k1 is provided in that the first base layer cutting line (B1) is situated at a distance from the first carrier layer cutting line (D1). This allows removal of a portion of the carrier layer which is situated outside the contours of the first carrier layer cutting line D1 in order to make the base layer with adhesive layer directly accessible and so form the first adhesive zone. Via the first adhesive zone (k1) the cover can be connected directly to the hollow object. The cover (100) can thus adhere to the upper surface (Ad1) of the hollow object. The first carrier layer cutting line (D1) extends along the whole length of the base layer cutting line (B2).

[0035] A re-adhesive zone k2 is provided in that the second base layer cutting line B2 is situated at a distance (d3) from the second carrier layer cutting line (M). The closing member (SL) can reclose the opening in that a part of the adhesive layer (LL) lies in the re-adhesive zone and substantially at the edges of the closing member. The part of the adhesive layer at the edges of the closing member (SL) can re-adhere to the re-adhesive surface (Ad2) of the base layer (BL), this imparting the cover with a reclosable property.

[0036] The closing member (SL) is shown in FIG. 1 in a U-shaped form. The second carrier layer cutting line (D2) and the second base layer cutting line B2 also have a U-shaped form. It is also possible that only the second carrier layer cutting line (D2) or only the second base layer cutting line (B2) has a U- or C-shape.

[0037] FIG. 1 shows that the distance (d3) is discontinuous along a segment of the first carrier layer cutting line (D1), wherein the segment length amounts to more than 20% of the overall length of the first carrier layer cutting line (D1). As already stated, this has the advantage that the cover can be fixed better and that stackability of the hollow objects can also be improved in this way. The underside of the upper second hollow object may rest on the cover of the first hollow object during stacking of for instance a second hollow object on a first hollow object with a cover, wherein the hollow objects typically have the same dimensions. It is important, particularly when a flexible cover is used, to provide a good connection or adhesion between the cover and the hollow object, since the cover may be subjected to forces because the weight of the upper hollow object rests on the cover. In cases of a flexible cover it is possible that these forces are distributed and transmitted to the connection or adhesion between cover and hollow object and/or to the fixing of the carrier layer relative to the hollow object. It is advantageous here for the first distance (d1) to be discontinuous along at least the segment with a segment length of at least 20% of the overall length of the first carrier layer cutting line, preferably at least 30%, still more preferably at least 40% and most preferably at least 50%. This also ensures that the carrier layer is fixed better relative to the hollow object.

[0038] For production engineering reasons it is desirable not to have to provide an additional adhesive layer or other additional adhesive element between the carrier layer and the hollow object. It is nevertheless desirable for the carrier layer to be fixed relative to the hollow object. In order to provide herefor the first carrier layer cutting line is non-linear at the position of the segment, as shown in FIG. 1. The first adhesive zone k1 enables the base layer to be connected directly to the hollow object. Because the base layer is connected directly to the hollow object, and the carrier layer is connected to the base layer, the carrier layer is also connected indirectly to the hollow object. The discontinuous distance d1 improves this indirect connection between the hollow object and the carrier layer.

[0039] FIG. 1 shows that the carrier layer cutting line (D1) follows on opposite edges of the cover a non-linear path (T) which has a wavy character. The non-linear path has the advantage that the cover can be fixed better onto a hollow object. This is for instance illustrated in FIG. 2A.

[0040] FIG. 2A shows the cross-section through section line IV shown in FIG. 1. Owing to the non-linear first carrier layer cutting line (D1), the carrier layer is secured indirectly to an upper surface (Ad1) of the packaging (200) without having to provide an additional adhesive element therebetween.

[0041] FIG. 2B shows the cross-section through section line III shown in FIG. 1. This shows that the cover can be connected directly to the packaging via the adhesive zone (k1). This has advantages in respect of production engineering and sustainability. The cover can be provided on the hollow object with a minimum number of layers, particularly a base layer (BL), an adhesive layer (LL) and carrier layer (DL). No additional adhesive elements are hereby necessary on the bottom of the carrier layer in order to attach the cover to the hollow object.

[0042] FIG. 3 shows a detail view of the cover shown in FIG. 1. Before being secured to a hollow object, the carrier layer part (DD) is removed so that the cover (100) can be secured via the first adhesive zone (k1) to a hollow object.

[0043] In a first case the cutting lines can cut substantially only partially through the respective layer in order to form a notch. In a second case the cutting lines can cut substantially through the whole thickness of the respective layer in order to form a full cut. A combination of notch and a full cut is also possible in a third case. If a notch is used, a local weakening of the respective layer is provided for, this being the base layer and/or the carrier layer as well as the adhesive layer, if present at the position of the cutting line. The notch at an edge of the closing member, this being the second base layer cutting line and, at the edge zone of the closing member, being the second carrier layer cutting line, can thus be easily torn by the local weakening so that the cover can be opened by tearing open the cover at least partially along the local weakening. When the adhesive layer (LL) is present at the position of the one of the cutting lines as described herein, this layer will also be cut through or cut into in the same or similar manner as the respective cutting line which is present.

[0044] The cutting lines can be provided by means of various cutting techniques, such as mechanical punching, using a blade or using laser cutting methods. The cutting lines can be provided completely or partially through the thickness of respectively the base layer and the carrier layer. With a partial provision of the cutting line a notch is formed which weakens the base layer and/or carrier layer at the position of the notch. Owing to this weakening, the notch can easily separate the adjacent parts of the layer by tearing the layer along the notch. The combination of a whole or partial cut along the length of the cutting line can also be provided, such as for instance a combination wherein the full cut and the partial cut alternate sequentially. A partial cut, for instance at the position of the second base layer cutting line (B2) can thus provide an indication that the cover has already been opened, since it will be torn in that case. Such an indication is also referred to as a tamper-proof or tamper-evident element. Tamper-evident elements are often desirable in packagings for providing a consumer or user with visual proof that the packaging is being opened for the first time.

[0045] The first base layer cutting line (B1) can also be formed at least partially by the side edges of a supply base layer coming from for instance a supply roll or feed roll which provides a film, for instance a PET film, to provide the base layer. The first carrier layer cutting line (D1) can also be formed by the side edges of a supply carrier layer coming from for instance a supply roll or feed roll which provides a film, for instance a PET film, to provide the carrier layer. In this way only the remaining cutting lines, these being the second base layer cutting line (B2) and the second carrier layer cutting line (D2) and optionally the third carrier layer cutting line (D3), need be provided with the known cutting line provision techniques.

[0046] The base layer (BL) can comprise one or more flexible layers with for instance a polymer film, paper, metal foil and the like. Typical polymer films of films on the basis of a synthetic plastic such as for instance Polyethylene (PE) both LLD, LD and HD, Polypropylene (PP), Polycarbonate (PC), polyvinyl chloride (PVC), polyamides (PA), Polystyrene (PS), Polyethylene terephthalate (PET). In other embodiments use can also be made of polymer films on the basis of biopolymers and/or biodegradable polymers. The base layer preferably comprises a layer of polyester, such as polyethylene terephthalate (PET). This material can be easily printed with inks in order to provide for example information about the content of the hollow object. In another embodiment the base layer is transparent and its surface facing toward the carrier layer is printed.

[0047] The carrier layer (DL) can comprise one or more flexible layers with for instance a polymer film, paper, metal foil and the like. Typical materials for forming the base layer comprise paper, plastic or a combination thereof. An example of a base layer is a synthetic layer on the basis of PP, PE, Polyester or a combination thereof. Typically used types of paper are for instance: Coated Paper, Uncoated Paper, Metallized Paper, Thermo Top Paper, Thermo Eco Paper, Opaque Paper, Wet-Strength Paper. It must be noted that other types of paper are also possible. It is preferably the case that the base layer comprises a polymer film as described above. A synthetic base layer has the advantage compared to paper that the cover is made suitable for a wider field of application, for instance also for use in humid conditions.

[0048] In respect of the base layer and the carrier layer it is the case that the base layer (BL) is preferably manufactured substantially from a first material (m1) and the carrier layer (DL) is manufactured substantially from a second material (m2). The first material (m1) and the second material (m2) preferably have substantially the same density and/or substantially the same melting temperature. It is preferably the case that the density of the first material differs from the second material by a maximum of 2%, preferably a maximum of 1%, most preferably a maximum of 0.5%. It is preferably the case that the melting temperature of the first material differs from the melting temperature of the second material by a maximum of 2%, preferably a maximum of 1%, most preferably a maximum of 0.5%. In the case that synthetic plastics are used for the first material and the second material, wherein it is desirable for these plastics to be recyclable, it is for instance advantageous for the plastic for both materials to be manufactured from the same type of polymer. For instance a base layer and a carrier layer manufactured substantially from PET, substantially here meaning more than 50% of the total layer.

[0049] When the base layer (BL) is manufactured substantially from the same type of material as the carrier layer (DL), advantages related to recycling are provided. In a recycling process it is advantageous for the input materials to contain largely the same types of material. This will reduce the need for separation processes. These aspects enhance the purity of the output materials in the recycling process.

[0050] One or more sub-layers can be provided on both the base layer and the carrier layer. A barrier layer which forms a barrier against the passage of moisture and/or oxygen can thus be provided. this is because it is important in some applications, such as packaging of moisture-sensitive products, to provide a moisture barrier. The barrier layer can comprise diverse barrier materials, such as ethylene vinyl alcohol copolymer (EVOH), polyamide (PA) or polyolefin films such as polyethylene (PE), polypropylene (PP), oriented polypropylene and the like. Films with aluminium foil, an AlOx coating or SiOx coating and the like can also be applied. Another example of a sub-layer is an adhesive force-reducing coating which reduces the adhesive force and/or the affinity of the adhesive layer and does not eliminate it completely. In an embodiment the adhesive force-reducing coating is applied at least at the position of the re-adhesive zone (k2). In addition, a layer of ink with information can also be provided on the base layer. Before the base layer is provided with the layer of ink, the base layer can be subjected to various treatments such as for instance a flame treatment or a corona treatment to make the surface more receptive to an ink layer. In addition or as an alternative it is also possible to adhere a separate label onto the base layer. This label typically shows information relating to the content of the hollow object.

[0051] The adhesive layer (LL) can comprise one or more types of adhesive. An adhesive is preferably selected which can typically be used in the label and/or sticker industry. Such adhesives are selected such that the adhesive force is considerably lower toward the carrier layer than toward the base layer. The lower adhesive force on the carrier layer makes the adhesive re-adherable to the carrier layer. The adhesive is also selected such that a good adhesion to an external surface can be realized. The skilled person will appreciate that the intended application influences the adhesive selected.

[0052] Examples of adhesives with a re-adhesive character are pressure-sensitive adhesives such as adhesives or adhesive tapes. Biodegradable adhesives and bioadhesives can also be applicable, these additionally having environmental advantages. Examples hereof are adhesives on the basis of vegetable matter, starch, casein, dextrin, glucose, methyl cellulose.

[0053] From a production engineering viewpoint it is advantageous for the adhesive layer to be provided as a continuous adhesive layer with an adhesive of the same type. The adhesive layer can here have a greater affinity with the base layer than with the carrier layer as shown in the figures. The degree of affinity can be modified by coating layers and/or material choice of the carrier layer and base layer. It is however preferred to provide a greater affinity between the base layer and the adhesive layer.

[0054] It is preferably the case that the adhesive layer comprises the same type of adhesive, this having advantages in terms of production engineering. A pressure-sensitive adhesive is preferably used. This is because pressure-sensitive adhesives can provide an adhesive force to the nearby components by simply pressing together or compressing these components, which does not require heating to any considerable degree. A plastic deformation of the adhesive layer occurs during compression, whereby a good initial adhesion is obtained. Examples hereof are adhesives on the basis of natural rubber, block copolymers (for instance SBS), PIB or butyl rubber, acrylates, silicones and polyvinyl ethers. The adhesive layer is preferably applied along the base layer as a continuous adhesive layer on the side of the base layer facing toward the carrier layer, which side should also be deemed the underside of the base layer. For reasons of production engineering, among others, it is advantageous to provide a pressure-sensitive adhesive over substantially the whole underside of the base layer.

[0055] An example of a suitable adhesive layer is the S4700 adhesive. This adhesive is commercially available through AVERY DENNISON.

[0056] The hollow object (200) can for instance be a packaging container. Such a hollow object preferably has a bottom and upright walls on all edges of the bottom. The upright walls have an upper edge at the top. The upper edge is preferably continuous, i.e. uninterrupted. Such a container can be manufactured from a variety of object materials, such as for instance a plastic. In order to enhance sustainability it is preferred to use sustainable materials for the hollow object, these including materials on the basis of paper, cardboard and/or materials on the basis of biodegradable and/or biodecomposable polymers such as polylactic acid (PLA) and/or containers from wood and/or on the basis of bamboo fibres, vegetable starch, biopolymers, paper pulp, rice pulp and so on. The hollow object can be used to package a determined content or substance (230). A hollow object can thus be provided for packaging for instance strawberries, cherry tomatoes, mushrooms, herbs, nuts, chewing gum and the like.

[0057] FIG. 4 shows a schematic representation of a cross-section of an embodiment of a reclosable cover (100) which is adhered to a hollow object (200). The base layer (BL) of the cover (100) is connected via the adhesive layer (LL) directly to the hollow object (200). It is not necessary here to provide additional adhesive elements between the carrier layer (DL) and the hollow object (200). The hollow object is provided to package a substance (230). Several ventilation holes (180) through the closing member (SL) are shown. The ventilation holes can bring the content (230) packaged in the hollow object into contact with an outside substance (231). In this way an air supply can be provided to the content of the hollow packaging. The ventilation holes can be arranged by means of perforation techniques.

[0058] FIG. 5 shows an embodiment of the invention with the same features as described above, and wherein the opening tab is shown. The opening tab (OL) is formed in that the first base layer cutting line (B1) and the second base layer cutting line (B1) overlap locally. The opening tab (OL) is further provided with a carrier layer portion (700) which is surrounded by a third carrier layer cutting line (D3) which is situated outside the contours of the first carrier layer cutting line.

[0059] FIG. 6 shows the cross-section through the section line VI shown in FIG. 5. The carrier layer portion (700) is surrounded by the third cutting line (D3) and ensures that a user who uses the opening tab (OL) to open the cover (100) does not come into direct contact with the adhesive layer (LL), or does so to lesser extent.

[0060] The skilled person will appreciate on the basis of the above description that the invention can be embodied in different ways and on the basis of different principles. The invention is not limited to the above described embodiments. The above described embodiments and the figures are purely illustrative and serve only to increase understanding of the invention. The invention will not therefore be limited to the embodiments described herein, but is defined in the claims.