Packing material with an opening arrangement, packaging container from this material and methods of producing same

Abstract: The disclosure relates to a packaging material (1) with an integrated opening arrangement (4), and a method of producing the same. The foundation layer (3) of a packaging material web (1) or a packaging material sheet is provided with a hole (5) or a hole indication (15). The hole (5) or the hole indication (15) is covered by a thin thermoplastic strip (7). Thereafter, the packaging material (1) is finished, with other laminate layers (8, 9, 10, 12). In such instance, the outer layer (12) will wholly cover the strip (7). When the strip (7) is torn off, the hole (5) is exposed in that those layers (8, 9, 10, 12) which are sealed to the strip (7) accompany the strip (7) when torn off.

Description: TECHNICAL FIELD The present invention relates to a packaging material with an opening arrangement comprising a prepared pouring aperture. The invention also relates to a method of producing the same and to a packaging container. BACKGROUND ART There are many requirements to be satisfied when providing a single use disposable package having an opening arrangement and being of the type manufactured from a continuous material web or an individual package blank. The opening arrangement must be easy to apply to the package. It must be easy to open and the consumer must be able to ensure that no-one has tampered with the package. In addition, the opening arrangement should not disrupt the path of the material web through the filling machine. In many respects, this has been achieved by exteriorly providing the package with a strip intended to be torn off when the package is opened, a so-called pull tab. Such pull tabs are known from DE-C-2729383 or SE-B-419327 wherein a package is exteriorly provided with a strip which can be torn off, thus opening the arrangement. The strip is attached to a distinct part of the packaging material which is perforated so as it sticks to the pull tab and is torn away during the opening procedure. As a result a hole opens up and the content can be poured out. It is also known that the strip is covered by an exterior layer which is torn off while opening the package. This layer is perforated to facilitate the opening procedure wherein the strip is bent 30 over the rim of the package and sticks out to form a pull tab. Such devices incorporate some disadvantages: The strip is normally applied in the filling machine, which necessitates register maintenance and additional workstations in the filling machine. Furthermore, an exteriorly located strip may cause problems on passage through that sterile bath with which aseptic filling machines are equipped, since residual products may remain on the edges of the strip. Even though the strip is made from a thin material, it still constitutes an additional structure on the packaging material, which may occasion problems in feeding the material web through the filling machine. Such a strip is as good as tamper-proof, but can nevertheless be manipulated. OBJECTS OF THE INVENTION One object of the present invention is to produce a packaging material with an integrated opening arrangement in which the opening arrangement is completely protected by the packaging material, and thereby also completely protected against unauthorized opening. The packaging material according to the present invention displays an almost homogeneous surface which does not disrupt the feeding of the material web through the filling machine and which cannot constitute a problem on passage through the sterile bath of the filling machine. A further object of the present invention is to realize a packaging material with an opening arrangement which enjoys all of the favourable properties possessed by prior art pull-tab opening arrangements. SOLUTION These and other objects have been attained according to the present invention according to claims 1, 11 and 16. Preferred embodiments of the present invention have further been given the characterizing features as set forth in the appended subclaims. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Preferred embodiments of the present invention will now be described in greater detail hereinbelow, with particular reference to the accompanying drawings, in which: Fig. 1 shows one embodiment of the present invention, partly in section; Fig. 2 shows the same embodiment of the present invention applied on a package container; Fig. 3 shows another embodiment of the present invention partly in section; and Fig. 4 is a top plan view of the embodiment of Fig. 3. The drawings show only those details essential to an understanding of the present invention. DESCRIPTION OF PREFERRED EMBODIMENTS Figs. 1 and 2 show a first embodiment of the present invention. The packaging material 1 which is employed to produce single-use disposable packages 2 manufactured from a continuous web or individual package sheets or blanks often consists of a laminate with a carrier layer 3 of cardboard or paper. Fig. 1 shows a cross section through such a laminate provided with an opening arrangement 4 according to the invention. As the foundation of the packaging laminate, use is made of the carrier layer 3 of cardboard or paper. This layer is provided with fold indications, so-called crease lines. In the same tool which makes the crease lines, it is possible to house a complete punching unit. By such means, additional register maintenance will be avoided and those holes which are to form the pouring aperture 5 of the opening arrangement 4 are already punched in the uncoated paper material web. The carrier layer 3 of the packaging material web 1 is provided, around the punched hole 5, with an adhesive layer 6 which can be applied in a so-called ink unit. Alternatively, the adhesive layer 6 can be placed on a tear-strip 7 which is to cover the punched hole 5. The thin tear-strip 7 is thereafter placed covering over the hole 5 and is secured against the carrier layer 3 of the packaging material web 1 with the aid of the adhesive layer 6, irrespective of whether this is pre-applied to the material web 1 or integrated in the tear-strip 7. Such a tear-strip 7 can be secured on a material web 1 which has an outer layer of thermoplastic or has a fusible carrier layer 3, by means of heat sealing. The tear-strip 7 consists of a thin plastic material which is normally laminated such that the carrier layer consists of a tear-resistant plastic material on both sides laminated with a thermoplastic. Other technical solutions are also conceivable employing materials which combine fusibility and a high tear index. In order to facilitate tearing off of the tear-strip 7 on opening of the package 2, the one end of the tear-strip 7 may be provided with an anti-adhesive coating. The anti-adhesive coating is placed on the tear-strip 7 on a small area at that end of the tear-strip 7 where the tearing-off operation is to commenced. Once the tear-strip 7 has been applied to the carrier layer 3 of the packaging material web 1, the packaging material 1 is finished by being provided with one or more inner layers which may consist of a bond layer 8 of thermoplastic and an aluminum foil layer 9, as well as an additional thermoplastic layer 10, which forms the surface of the packaging material 1 facing the contents of the package and hereafter designated the opposed side 11 of the packaging material 1. The packaging material is further provided with an outer layer 12 normally consisting of a thermoplastic. Hereby, the tear-strip 7 will wholly be covered by this thermoplastic layer 12. The thermoplastic layer 12 forms the surface of the packaging material 1 facing away from the contents of the package and hereafter designated the reverse side 13 of the packaging material 1. A packaging material 1 has now been obtained with an integrated opening arrangement 4. This packaging material 1 easily runs through the filling machine without causing any problems resulting from residual products in the sterile bath. The packaging material 1 is formed into a tube, filled with liquid food, and transversely sealed into individual packages 2 which are then cut off and finally formed. In order to facilitate opening of the opening arrangement 4 according to the invention, the finished package 2 can, after final forming, be provided with an exterior gripping strip 14 fixedly sealed over a portion of the interiorly applied plastic tear-strip 7. The gripping strip 14 suitably carries print in a different colour so as to indicate where the opening procedure is to take place. Figs. 3 and 4 show a second embodiment of the present invention. Also in this embodiment, the point of departure is the carrier layer 3 of the packaging material 1, the carrier consisting of cardboard or paper. In that tool where the crease lines are formed, a hole indication 15 is also made by perforating the carrier layer 3. The width of the hole indication 15 shooed correspond to the width of that tear-strip 7 which is to be applied on the carrier layer 3. The one short side of the hole indication 15 is provided with a completely penetrating slit 16. The tear-strip 7 is applied in the same manner as described above, by an adhesive layer 6 or by heat sealing, but the tear-strip 7 is placed on the opposed side 11 of the packaging material 1. Once a part of the tear-strip 7 has been applied against the carrier layer 3, the remaining part of the tear-strip 7 is passed through the slit 16 in the short side of the hole indication 15 and that part of the tear-strip 7 which then arrives at the reverse side 13 of the packaging material is folded along the surface of the reverse side 13. The packaging material 1 is finished in the customary manner, with different laminate layers as shown in Fig. 3. The same second embodiment is illustrated in top plan view in Fig. 4. Here, the finished packaging material 1 has been exteriorly provided with a gripping strip 14 which indicates where the tearing-off operation is to be commenced. When the opening arrangement 4 according to the invention is opened, the tear-strip 7 located inside the outer thermoplastic layer 12 is torn off, commencing at the gripping strip which is applied on the outside of the package 2. When the tear-strip 7 placed inside the thermoplastic layer 12 is torn off, it draws with it the layer or layers to which it is sealed so that the hole 5 is exposed and the contents of the package 2 can be poured out. The layers to which the tear-strip 7 is sealed are at least one in number, namely the thermoplastic layer 12 which covers the tear-strip 7, but may, depending upon the construction of the packaging material 1, consist of a plurality of layers. In the second embodiment, the hoe indication 15 in the carrier layer 3 to which the tear-strip 7 is connected also accompanies the strip when torn off. This hole indication 15 can be employed for reclosing in that it is once again pressed down in the hole 5 which is exposed when the tear-strip 7 is torn off. The tear-strip 7 is easy to tear off, in that the outer thermoplastic layer 12 is partly weakened at the edges of the tear-strip 7 where the outer thermoplastic layer 12 is somewhat thinner on application. In order further to improve the tearing off operation, these edges can moreover be weakened by heat treatment. An opening arrangement 4 according to the present invention can also be applied to other materials in web or sheet form, in which the carrier or base consists of another material than paper or cardboard. These packaging materials 1 are provided with punched holes 5 which are covered by a tear-strip 7, whereafter the tear-strip 7 is completely or partly covered with an outer thermoplastic layer 12. The outer thermoplastic layer 12 can wholly cover the tear-strip 7 but only partly cover the finished packaging container 2. Other designs of such a tear-strip 7 are also possible. For example, the packaging material 1 can be provided with a tear-strip 7 according to the invention in the transverse sealing region (a so-called spout strip), this strip entraining the layer to which it is sealed when torn off. In such instance, a small section of the transverse seal joint is opened and forms an opening and pouring arrangement. In addition, such a tear-strip 7 can be employed for realizing a pull-tab integrated in the packaging material 1, in which the material 1 is vacuum-shaped into a pipe or socket in a later process, possibly provided with threads for cooperation with an outer screw cap. Another form of opening arrangement in which the tear-strip 7 according to the invention can be employed is that type of tear-strip 7 which passes around the package 2. In this instance, the tear-strip 7 takes with it all of those surfaces which are sealed to the tear-strip 7 and by such means opens the package 2. As will have been apparent from the foregoing description, the present invention realizes a packaging material with a wholly integrated opening arrangement which lies completely protected before being opened and which cannot be improperly opened or tampered with in any way. The packaging material is completely ready for the filling machine without the filling machine needing further workstations for hole making and applying pull-tab strips.

Claims: Packaging material (1) with an opening arrangement (4) comprising a pouring aperture (5) prepared in a carrier layer (3) of the packaging material, the pouring aperture (5) being covered by a tear-strip (7) which is applied on the carrier layer (3) and which can be disposed, on opening, to expose the pouring aperture (5) and wherein the exposed portion or portions of the tear-strip (7) are partly or completely covered by an additional material layer or by additional material layers, respectively. Packaging material (1) as claimed in claim 1, wherein said tear-strip (7) is sealed to said additional material layer or to said additional material layers, respectively, wherein said layer or layers accompany said tear-strip (7) while tearing off said tear-strip (7). Packaging material (1) as claimed in claim 1 or 2, wherein said tear-strip (7) is partly or completely placed on the reverse side (13) of the packaging material (1) beneath an outer layer (12). Packaging material (1) as claimed in one of the preceeding claims, wherein said tear-strip (7) is partly placed on the opposed side (11) of the packaging material (1) and partly placed on the reverse side (13) of the packaging material (1) wherein said tear-strip (7) extends through a slit (16), linking both sides (11, 13). Packaging material (1) as claimed in one of the preceeding claims, wherein said carrier layer (3) has an outer layer of thermoplastic or consists of fusible material and that said tear-strip (7) is applied on the carrier layer (3) by means of heat sealing. Packaging material (1) as claimed in one of the preceedings claims, wherein said tear-strip (7) is applied on the carrier layer (3) by means of an adhesive layer (6) which is placed on said tear-strip (7) or which is provided around the pouring aperture (5). Packaging material (1) as claimed in claim 6, wherein said adhesive layer (6) is integrated within said tear-strip (7). Packaging material (1) as claimed in one of the preceeding claims, wherein one end of the tear-strip (7) is provided with an anti-adhesive coating and/or is not connected to adjacent layers (3). Packaging material (1) as claimed in one of the preceeding claims, wherein said tear-strip (7) consists of a laminate. Packaging material (1) as claimed in one of the preceeding claims, wherein said additional material layer or additional material layers consist of an outer layer (12) and/or of several inner layers (8, 9, 10). Packaging container (2) comprising a packaging material (1) as claimed in one of the preceeding claims, wherein a gripping strip (14) is fixedly attached to said portion or portions of said tear-strip (7) and said gripping strip (14) is situated exterior to said outer layer (12) of said packaging container (2). Packaging container (2) as claimed in claim 11, wherein said gripping strip (14) is colored in a different color than the surrounding layers. Packaging container (2) as claimed in claim 11 or 12, wherein said additional material layer or said additional material layers covering said tear-strip (7) accompany said tear-strip (7) during the tearing off procedure of said tear-strip (7). Packaging container (2) as claimed in one of the claims 11 to 13, wherein also said carrier layer (3) accompanies said tear-strip (7) during the tearing off procedure. Packaging container (2) as claimed in one of the claims 11 to 14, wherein said additional material layer or said additional material layers are partly weakened at the edges of the said tear-strip (7) to facilitate the tearing off procedure. A method of producing a packaging material (1) with an opening arrangement (4) comprising a pouring aperture (5) prepared in a carrier layer (3) of the packging material, comprising the step of covering said pouring aperture (5) by a tear-strip (7) which is applied on the carrier layer (3) and thereafter covering partly or completely the exposed portion or portions of said tear-strip (7) by an additional material layer or by additional material layers, respectively. The method of producing a packaging material (1) as claimed in claim 16, wherein said carrier layer (3) is provided with an adhesive layer (6) prior to the application of said tear-strip (7) or that said tear-strip (7) is provided with an adhesive layer (6) prior to the application of said tear-strip (7) on the carrier layer (3). A method of producing a packaging container from the packaging material (1) produced by the method according to claims 16 or 17, wherein a gripping strip (14) is fixedly attached to that portion or portions of said tear-strip (7) exterior to said outer layer (12) after finally forming the packaging container (2).

Inventors: ANDERSSON INGVAR, ANDERSSON THORBJOERN, ANDERSSON, INGVAR, ANDERSSON, THORBJOERN, Andersson, Thorbjörn 
Applicants: TETRA LAVAL HOLDINGS & FINANCE, TETRA LAVAL HOLDINGS & FINANCE SA
Application year: 1993
Main classification: B65D5
IPC codes: B65D5