Patent Application
20220267079
The invention relates to a reclosable cover, wherein the cover is suitable for closing a hollow object, such as for instance a packaging container, such that a user can open and reclose the cover.
In the packaging industry there are various types of cover which have been developed to at least partially close a hollow object, including for instance “a receptacle” or “a packaging container”, and provide it with an opening, wherein the opening can open and close. Various designs have been created here for making the opening reclosable.
A first type of cover which is reclosable and can be secured onto a packaging is described in EP0447329. The periphery of this cover is snapped mechanically onto a corresponding edge of a receptacle. Although the design is frequently used, it is subject to several drawbacks. This is because, in terms of production engineering, the design is difficult to produce, typically by means of thermoforming techniques or casting techniques. This design is also disadvantageous in terms of sustainability. Not only is a lot of energy needed to produce the cover, a relatively large amount of material is also needed to manufacture the cover. This is undesirable for environmental reasons, among others. Different moulds must further be produced and provided to produce such a cover for different hollow objects, which greatly reduces flexibility and greatly increases cost price. In addition, the receptacle requires a modified corresponding edge so that the cover can snap fixedly onto it.
Another type of cover is described in EP2243716, more specifically in the passage related to the embodiment shown in
The object of the invention is to provide an alternative reclosable cover which can be arranged on different types of hollow object in simple manner.
The invention provides for this purpose a cover provided with the features as described in claim 1. More specifically, the invention provides a reclosable cover for a hollow object, wherein the cover comprises: a base layer, wherein a rear side of the base layer is provided with a carrier layer and wherein an adhesive layer is present between the base layer and the carrier layer, and wherein the base layer has a first base layer cutting line to form a peripheral edge of the cover; wherein the carrier layer has a first carrier layer cutting line, lying substantially inside contours of and at a first distance from the first base layer cutting line, to provide a first adhesive zone when a carrier layer part outside the first carrier layer cutting line is removed; wherein the first adhesive zone is formed to adhere the cover to the hollow object; wherein the base layer has a second base layer cutting line, lying substantially inside the contours of and at a second distance from the first carrier layer cutting line, to form a closing member; wherein the carrier layer has a second carrier layer cutting line, lying substantially inside the contours of and at a third distance from the second base layer cutting line, to provide a re-adhesive zone between the second carrier layer cutting line and the second base layer cutting line.
The invention is based on the insight that material for making labels and stickers can be used to make a reclosable cover though an ingenious provision and layout of cutting lines. The reclosable cover can hereby not only be produced in simple manner but also be arranged on different types of hollow object in simple manner, particularly both plastic packaging containers and containers made of paper and cardboard or any other material. Using the first adhesive zone provided by the first base layer cutting line and the first carrier layer cutting line the cover can be provided directly on a hollow object without the use of complex heating equipment. The reclosable cover can here be manufactured in simple manner from materials that are already available and widespread in the label and sticker industry. The regular label and/or sticker materials can be used to provide the base layer and the carrier layer. After being provided with the cutting lines as described here, they can be transported as a “sticker roll” to the packager wishing to use a reclosable cover to provide a hollow object with a reclosable cover. Owing to the clever provision of the cutting lines, the packager need not resort to complex heating equipment, and the packager can sustainably provide the reclosable covers on hollow objects, preferably sustainable packaging containers such as containers made of paper, cardboard, wood, bioplastics such as polylactic acid (PLA) and/or containers on the basis of bamboo fibres, vegetable starch, biopolymers, paper pulp, rice pulp. Arranging of the covers can be performed by a packager using known labelling machines that are typically known as flexible in use, particularly for different label types and widths. An alternative reclosable cover is hereby provided which can be arranged on different types of hollow object in simple manner.
It is preferably the case that the first distance is discontinuous over at least a segment of the first carrier layer cutting line, this segment having a segment length which amounts to at least 20% of an overall length of the first carrier layer cutting line. This has the advantage that the cover can be better fixed on a hollow object. More specifically, the width of the first adhesive zone will periodically increase due to the first distance being discontinuous, so that the width of the first adhesive zone between the hollow object and the cover also increases periodically. This improves the adhesive force distribution, whereby shearing forces which may occur can be better absorbed. At the same time, the carrier layer is fixed in improved manner relative to the hollow object. The improved fixing also ensures that the stackability of the hollow objects can be improved.
It is preferably the case that the first carrier layer cutting line is non-linear at the position of the segment. A better power distribution can hereby be obtained through the cover and/or the connection between cover and hollow object, and the cover can be secured properly onto a hollow object. The carrier layer can here also be properly secured relative to the hollow object without an additional adhesive element having to be provided between carrier layer and hollow object. It is preferably the case that the segment follows a path which has a repetitive pattern. The repetitive character of the pattern has advantages in terms of production engineering and provides for a uniform distribution of the first adhesive zone, so that the cover can be fixed uniformly along the edges of the hollow object.
It is preferably the case that the first carrier layer cutting line extends along substantially the whole first base layer cutting line. This so that the first adhesive zone can extend along substantially the whole base layer so that an optimal connection can be provided between cover and hollow object.
It is preferably the case that the second base layer cutting line is situated substantially in edge zones of the cover. It is thus desirable that more than 40%, preferably more than 50% of the second base layer cutting line is situated in edge zones of the cover. The edge zones indicate the zones which are situated closer to the peripheral edges of the cover than the centre of the cover. This so that a desired opening can be provided, so that a user can easily gain access to a content of the hollow object, such as for instance a strawberry.
It is preferably the case that the second base layer cutting line and/or the second carrier layer cutting line is substantially C- or U-shaped. An opening is hereby provided between the legs so that the content of the hollow object is available. The C- or U-shape creates between the outer ends of the legs of the C or U a connection of carrier layer and/or base layer to the part of the cover which is connected to the hollow object. This connection ensures that the closing member of the cover remains in the vicinity of the cover. In this way it is prevented that the closing member is lost during functional use of the cover and/or the hollow object. The connection provides for a hinge function of the closing member.
It is preferably the case that the base layer is manufactured substantially from a first material and the carrier layer is manufactured substantially from a second material; wherein the first material and the second material have substantially the same density and/or substantially the same melting temperature. Because both materials have substantially the same density and/or melting temperature, it is assumed that both materials are of the same kind and/or type, for instance both materials from one of PET, PE, PP, PVC and the like. This ensures that the cover can be recycled more easily and/or efficiently in a later recycling process. This enhances the sustainability. It is preferably the case that the first material has substantially the same colour as the second material, this also being advantageous for the recyclability. Suitable materials will be discussed in more detail below.
It is preferably the case that the adhesive layer comprises mainly a pressure-sensitive adhesive. The adhesive consists substantially of pressure-sensitive adhesive, this being a type of non-reactive adhesive which forms a connection when pressure is exerted in order to adhere the adhesive to a surface. Solvent, water or heat are typically not needed in order to activate the adhesive. The cover can hereby simply be fixed on the hollow object, without the necessity for lengthy curing steps or heating steps. Suitable pressure-sensitive adhesives are the adhesives typically used in the label and sticker industry. Examples of suitable pressure-sensitive adhesives will be discussed in more detail below.
In an embodiment it is the case that the cover is provided with one or more ventilation holes lying substantially inside the contours of the second carrier layer cutting line. The content of the hollow object can be ventilated hereby.
In an embodiment it is the case that the closing member is further provided with an opening tab which is surrounded in that the first base layer cutting line and the second base layer cutting line overlap at the position of the opening tab. It is preferably the case that the opening tab is provided with a carrier layer portion which is formed by a third carrier layer cutting line situated at least partially outside the contours of the first carrier layer cutting line. This has the advantage that a user of the opening tab is less likely to come into contact with the adhesive layer, which contact may be considered unpleasant by a user.
The invention further relates to the hollow object comprising at least one reclosable cover as described here. Because the hollow object has this label, the object as a whole can be recycled more easily. Particularly when sustainable materials are used for the hollow object. Such materials will be discussed in more detail below. It is preferably the case that the reclosable cover is fixed on the hollow object via the first adhesive zone. This has the advantage that the necessity and/or the use of other adhesive layers are reduced and/or avoided.
The invention further relates to a method for manufacturing a reclosable cover, comprising the steps of: providing a laminate with a base layer and a carrier layer on a rear side of the base layer and providing an adhesive layer between the base layer and the carrier layer; providing a first base layer cutting line on the base layer to form a peripheral edge of the cover; providing a first carrier layer cutting line on the carrier layer, substantially inside the contours of and at a first distance from the first base layer cutting line, to provide a first adhesive zone; providing a second base layer cutting line on the base layer, substantially inside the contours of and at a second distance from the first carrier layer cutting line, to form a closing member; providing a second carrier layer cutting line on the carrier layer, substantially inside the contours of and at a third distance from the second base layer cutting line, to provide a re-adhesive zone between the second carrier layer cutting line and the second base layer cutting line. In this way the method provides for manufacturing a reclosable cover in a manner which is simple in terms of production engineering, particularly without making use of complex production techniques such as for instance heating techniques. The advantages and effects as described above with reference to the reclosable cover also apply at least largely to the method. In addition, a relatively large number of reclosable covers can in this way be provided in a short time span. The method preferably further comprises of: placing the reclosable cover on a hollow object by removing a first carrier layer part outside the first carrier layer cutting line.
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.
The cutting lines are situated substantially largely in the order, as seen from the peripheral edge of the cover inward:
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.
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).
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.
The closing member (SL) is shown in
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
An example of a suitable adhesive layer is the S4700 adhesive. This adhesive is commercially available through AVERY DENNISON.
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.
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20215125 | Feb 2021 | BE | national |
| 20215833 | Oct 2021 | BE | national |
