EP0121891A2 - Package blank as a container for a sheet - Google Patents

Abstract

1. A container for a foil sheet (3) in the form of a package blank (1, 31) with a bottom (4), a back wall (9), a cover (12) and a side wall (8) and with a tear-off edge (20) situated between two end walls (6) and being provided with teeth (24) which terminate in a triangle, determined for separating the foil sheet which can be guided across the tear-off edge (20) by pulling at the free end of the foil, with the centre lines (N) of the teeth (24) running about perpendicular to the adjacent edge of the package blank characterized in that the course of the tear-off edge (20) is determined by a line of curative (K2 ) as geometric locus for the tips (23) of the teeth (24), whose centre is situated approximately on the centre line (M) of the longitudinal middle of the box, and that the tips (23) of the teeth (24) are formed by a triangle (25) of an aperture angle (W) of about 40 degrees.

Description

The invention relates to a packaging box as a storage container for a film web with a tear-off edge arranged in a side wall of the box for severing the film web which can be guided over this by pulling on the free film end.

A packaging box of this type is disclosed by GB-PS 1 282 045; the cuboid, elongated cardboard packaging box is intended to hold rolled metal foils, which can be separated in the area of a corrugated tear-off edge. This slightly corrugated tear-off edge runs as a straight tear zone in the middle of a side wall of the packaging box. Such tear-off edges are sufficiently effective with metal foils, which also applies to so-called corundum strips of DE-OS 29 27 195.

However, it has been shown in practice that when using - increasingly desired - high-stretch transparent films such tear-off edges remain completely inadequate; these highly stretchable films deform over the waves mentioned, but this does not initiate the desired separation process. So far, it has not been possible to create an effective tear-off edge as an integral part of a packaging box made of cardboard, with which even highly stretchable films can be cut without problems. In this context, it should only be pointed out that such foils, placed over a human hand, can be deformed into a glove without tearing.

In view of these circumstances, the inventor has set the goal of equipping a packaging box of the type mentioned at the outset with a tear-off edge in such a way that even high-stretch films can be used in sections in the usual way.

To solve this problem, the tear-off edge is designed as a tooth edge curved in the pulling direction. This curvature allows the areas near the edges of the film to come into contact with only a few teeth, so that only a small area of the film has to be applied with the entire tensile force; if the outer teeth are in contact with the film, this only comes into contact with other teeth in the central area.

For this purpose, it has proven to be advantageous that the tooth edge has at least two ^g e-curved ridge lines running at a distance from one another as geometric locations for tooth tips, ie that at least two curved so-called attack zones are formed, which are formed by those tooth tips.

Another essential component of the invention is that the center lines of the triangular teeth run parallel to the direction of pull; it would be obvious to arrange those center lines perpendicular to the ridge lines, but this would lead to undesired component directions. It has been shown that the direction of the center lines of the triangular teeth described above offers optimal tear-off conditions.

The two - or more - ridge lines determine larger and shorter teeth which, according to a further feature of the invention, are arranged in alternation with one another, it having proven particularly advantageous to arrange the tips of these teeth in such a way that the film is in the pulling direction first hits the tip of a large tooth, then the tip of the adjacent large tooth and only then touches the tip of the small tooth in between. This considerably increases the mode of operation of the packaging box according to the invention for the purpose seen by the inventor.

It is of further importance that the distance between the crease line delimiting the side wall on the one hand and the base line delimiting the tooth edge in the pulling direction on the other hand is smaller at its apex than half the height of the side wall; this eliminates the deflection of the central wall area at the tear-off edge, which is known from other packaging boxes and occurs when the train is pulled. As is well known, this temporary deformation often leads to tearing of the side wall from the tear-off edge.

In another embodiment of the tooth edge, this defines a straight ridge line up to the center of the side wall or beyond which is inclined to the direction of pull. It is also possible to have a straight tooth edge section inclined in this way merge into a curved part, for example near the center of the side wall.

Within the scope of the invention there is also a packaging box of the type mentioned at the outset, the side wall containing the tear-off edge of which is assigned a cutting strip which is designed to be divisible by at least one predetermined tear line into a cover flap and a pulling strip, this pulling strip before the packaging box is put into use, i.e. before first access to the transparent film on which the packaging box, in particular on that side wall, is fixed. This pull strip is separated by a short tensile stress and then releases the cover flap, which is inserted into the interior of the box for use in the manner already described and then forms a through-slot for the transparent film with the side wall containing the tear-off edge.

According to the invention, the cover flap can also be fixed to the packaging box in a manner other than that described; of importance to the invention remains that it is shorter than the side wall containing the tear-off edge, so that it can be placed under pressure on the cover strip of the packaging box, at least at maximum diameter, of a film roll formed by the transparent film.

It is within the scope of the invention that a permanent adhesive layer is assigned to the free lower edge of the short cover flap, which adheres briefly to the transparent film when the cover flap is pressed down and raises it thanks to the restoring forces in the cover strip when it is reshaped so that a user can grip the transparent film and can bring in tear-off position. The user therefore presses the lid strip of the packaging box down towards the inside of the box and releases it again briefly in order to achieve the lifting effect described. Once he has grasped the free end of the film, he pushes the cover strip downwards again and creates an abutment with the free lower edge of the cover flap, which greatly facilitates the tear-off of the high-stretch transparent film.

According to the invention, the blank for producing the packaging box can have one or more of the features which are described in the above description and in the claims for the packaging box itself.

• Fig. 1: die Draufsicht auf einen Zuschnitt für eine quaderartige Kartonschachtel;
• Fig. 2: einen stark vergrößerten Ausschnitt aus Fig.1;
• Fig. 3: einen Teil einer aus dem Zuschnitt der Fig. 1 hergestellten Kartonschachtel in Schrägsicht mit einer in ihr vorgesehenen Klarsichtfolie;
• Fig. 4: ein Detail zu einer weiteren Ausführungsform;
• Fig. 5: eine der Fig. 1 entsprechende Darstellung des Zuschnitts für eine andere Kartonschachtel;
• Fig. 6: eine Schrägsicht auf die Kartonschachtel zu Fig. 5 in geschlossener Lage;
• Fig. 7: eine Schrägsicht auf einen vergrößerten Teil der Fig. 6;
• Fig. 8: den in Fig. 7 gezeigten Teil während des Öffnungsvorganges;
• Fig. 9: die Kartonschachtel nach dem öffnen in Schrägsicht;
• Fig. 10: einen vergrößerten, durch die in eine Arbeitsstellung überführte Kartonschachtel der Fig. 6 gelegten, schematischen Querschnitt etwa gemäß deren Linie X - XI während einer Ziehposition für die Klarsichtfolie;
• Fig. 11: eine der Fig. 10 entsprechende Wiedergabe in Abreißposition für die Klarsichtfolie.

Further advantages, features and details of the invention emerge from the following description of preferred exemplary embodiments and with reference to the drawing; this shows in:

• 1: the top view of a blank for a cuboid cardboard box;
• 2: a greatly enlarged detail from FIG. 1;
• 3: a part of a cardboard box made from the blank of FIG. 1 in an oblique view with a transparent film provided in it;
• 4: a detail of a further embodiment;
• 5: a representation corresponding to FIG. 1 of the cut for another cardboard box;
• 6: an oblique view of the cardboard box of FIG. 5 in the closed position;
• FIG. 7: an oblique view of an enlarged part of FIG. 6;
• Fig. 8: the part shown in Fig. 7 during the opening process;
• Fig. 9: the cardboard box after opening in an oblique view;
• FIG. 10: an enlarged, schematic cross section through the cardboard box of FIG. 6, which has been moved into a working position, approximately along its line X-XI during a pulling position for the transparent film;
• 11: a representation corresponding to FIG. 10 in the tear-off position for the transparent film.

The cut for a cuboid cardboard box 1 - or a box made of a corresponding material - for receiving a high-stretch transparent film 3 wound on a cardboard tube core 2 consists according to FIG Longitudinal edges 7, adjacent side walls 8, 9.

The two side walls 8, 9 are provided with buckles 11 along their top edges 10, which are formed by fold lines like the top edges 5. In addition, the one side wall 9 is separated from a cover strip 12 and this from an attached cover flap 13 by a crease line 14 and 15, respectively.

The blanking strips 8, 4, 9, 12 are generally of the same height h; the length of the cover flap 13 or of its free flap edge 16 is slightly shorter in FIG. 1 by a dimension 2 · n than the length i of the cut strips 8, 4, 9, 12, that recess dimension n is between the side edges 17, 18 of Cover strip 12 and cover flap 13 can be seen.

The side wall 8 lying above in FIG. 1 reveals a toothed rim 20 which is part-circular around a center point M located on the center line M - and outside the drawing sheet - which starts at both ends from the longitudinal edge 19 of the side wall 8 and its base line S in that cutting line M has its apex Z; its distance e from the adjacent longitudinal edge 7 forming a crease line is, for example, one third of the strip height h.

The size ratios become clear when you assume the strip height h with, for example, 45 mm and the strip length i with, for example, 305 mm.

The tooth edge 20, which is enlarged and shown schematically in FIG. 2, is delimited towards the side wall 8 by that base line S. A first ridge line K ₁ runs at a radial distance a therefrom, to which a second ridge line K ₂ can be seen in the radial distance b; these radial distances a, b are approximately the same length, the radii of the curved lines S, K ₁ and K ₂ in Fig. 1.5 indicated by r _s , r ₁ and r ₂ .

The first ridge line K ₁ is the geometrical location of the tips 21 of short teeth 22 of the tooth edge 20. The latter alternate with larger teeth 24, the tips 23 of which determine the ridge line K ₂ .

The tips 23 of the large teeth 24 belong to small triangles 25, one of which is in the right half 2 is hatched. The side edges 26 of the triangle 25 enclose an angle w of 40 ⁰ and extend to a line 27 which q runs from the top 23 and determine from the starting side edge portions 26 _{a has} an opposite w greater included angle w ₁ of 60 ° at a distance . The inclusion angle t of the short teeth 22 is 50 °.

The distances f lying horizontally in FIG. 2 between the tips 21, 23 of adjacent teeth 22, 24 are slightly larger than the double distance q at the triangle 25 in the selected exemplary embodiment. The distance g between two tips 23 of large teeth 24 obviously corresponds to twice the distance f.

The center lines N of the large teeth 24 and the center lines Q of the short teeth 22 run parallel to one another and are i. w. perpendicular to the longitudinal edges 7 and thus in the pulling direction x for the transparent film 3 of high elasticity.

If the cardboard box 1 is produced according to FIG. 3 and the transparent film 3 is placed with its pulling end 39 over the tooth edge 20, then a fold line 40, indicated by dash-dotted lines in the drawing, is created between the two outer teeth 24 in the drawing, in the direction of the train x the transparent film 3 is first scored by the outer teeth 24 _e and then - in each case on both sides of the line of symmetry M - touches the following tooth 24 and then the outermost tooth 23 of the ridge line K ₁ , which lies between the first two teeth 24 of the ridge line K ₂ lies.

In the procedure described, the transparent film 3 is perforated in steps from the film edges 41 to the inside. The transparent film 3 is completely severed when the tooth 24 assigned to the vertex Z has started to operate. It is clear that the position of the center lines N, Q described in the pulling direction x which is essential for the tearing process has a considerable influence on the separating action. The same applies to the arrangement of the tooth tips 21, 23 alternately on different comb lines K ₁ and K ₂ , the distance b of which is less than the distance f of the tips 21, 23 from one another.

Fig. 4 illustrates an embodiment with a straight ridge line R, which - with the line 40 following the course of the omitted longitudinal edge of the side wall 8 - includes an angle of inclination y of approximately 12 °. The tip areas determined by the triangles 25 are additionally impregnated with a hardener.

When the cardboard box 31 shown in FIG. 6 is cut 32, a cut strip 33 is connected to the cover strip 12, which is provided with a predetermined tear line 34 at a distance c (e.g. 1/3 h) from the flap edge 16. This ends at gusset-like edge incisions 35 and divides the blanking strip 33 into a cover flap 13, which is narrower than in FIG. 1, and a pulling strip 36 of precisely that width c.

As can be seen above all in FIG. 7, with a cardboard thickness p that is greatly excessive for reasons of clarity, there is one over the predetermined tear line 34 rectangular multilayer flap 44 glued from a double-sided adhesive strip 45 and a protective strip 46 covering it. The double-sided adhesive strip 45 has a separating cut 47 above the predetermined tear line 34, so that when pulling on the tapering grip end 37 of the pull strip 36 which is tacked onto the side wall 8 and can thus be detached therefrom, the predetermined tear line 34 is severed and with the pull strip 36 that of the separating line 47 limited section 45 _{a of} the double-sided adhesive strip 45 including protective strip 46 is lifted off (FIG. 8). A narrow, slightly adhesive adhesive strip then remains on the cover flap 13 for 45 _hours .

Thanks to the short height h ₁ of about 2/3 h of the cover flap 13 _i , the cover strip 12 can be pressed onto the film wrap 3 _w by the indicated finger of a user - or the bottom edge 34 of the flap 34 _{i placed} on the box bottom 4 - and then on Adhesive strips 45 _h hanging transparent film 3 are lifted into the pulling position shown in FIG. 10. This is particularly advantageous when the pulling end 39 of the transparent film 3 has crept into the cardboard box 31 after a long period of rest.

If the cover strip 12 has returned to the pulling position according to FIG. 10 after the described capturing of the transparent film 3 and its release, the user can grip the pulling end 39 and place it around the tooth edge 20 in the manner already discussed. Then the cover strip 12 is again by the user's finger in the tear-off position according to Fig.1 transferred; there is a certain tension between the tooth edge 20 and the lower edge 34 _i of the cover flap 13 _i , which favors the tearing process. The adhesion of the transparent film 3 to the adhesive strip 45 _h is not so great that this could be a hindrance during the tear-off process.

In another embodiment of the cardboard box 31 according to FIG. 9, the adhesive strip has remained 45 _{h in} total on the cover flap 13 _i , which in the vicinity of that adhesive strip 45 _{h has} a strip-like formation 50 which the lower edge 34 _i offers. Obviously, in this embodiment, the pull strip 36 already removed in FIG. 9 is designed accordingly.

Claims (12)

1. Packaging box as a storage container for a film web with tear-off edge arranged in a side wall of the box for severing the film web that can be guided by pulling on the free film end, characterized in that the tear-off edge is designed as a tooth edge (20) curved in the pulling direction (x). 2. Packaging box as a storage container for a film web with tear-off edge arranged in a side wall of the box for severing the film web that can be guided by pulling on the free film end, characterized in that the tear-off edge from one to the longitudinal edge of the side wall (8) at an angle (y) inclined at least partially straight tooth edge (20) is formed, the tooth edge (20) preferably merging into a curve toward the center of the side wall (8). 3. Packaging box according to claim 1 or 2, characterized in that the tooth edge (20) has at least two spaced (b) mutually extending curved ridge lines (K) as geometric locations for tooth tips (21, 23), where appropriate that of the pulling direction (x) first ridge line (K ₂ ) associated teeth (24) with the shorter teeth (22) of the other ridge line (K ₁ ) are arranged alternately and / or the tips (23) of two adjacent large teeth (24) to each other - in Direction of pull (x) seen - closer than the tip of the tooth (24) touched first in the pulling direction to the tip (21) of the short tooth (21) lying between the two large teeth. 4. Packaging box according to one of claims 1 to 3, characterized in that the center lines (N, Q) of the triangular teeth (22, 24) parallel to the direction of pull (x) and optionally perpendicular to the adjacent box edge (7), and / or that a tip (23) of the large tooth (24) forming triangle (25) has an opening angle (w) of approximately 40 °, preferably the base (27) of the triangle (25) on both sides of kinks in the side edges (26) of the Tooth (24) is determined and the opening angle (w _l ) between the edge sections (26 _a ) following in the pulling direction (x) measures approximately 60 °, while the inclusion or opening angle (t) between the side edges of the small tooth (22) approximately Is 50 °. 5. Packaging box according to one of claims 1 to 4, characterized in that at least the area between the side edge (26) of the tooth (22 or 24) emanating from the tip (21 or 23) is treated with a hardener, and / or that between the adjacent side edges of a large and a small tooth (24, 22), a pitch circle contour determines the base of the tooth valley, the radius of the pitch circle contour preferably being slightly smaller than the distance (b) of the ridge lines (K ₁ , K ₂ ) from one another. 6. Packaging box according to at least one of claims 1 to 5, characterized in that the center of the radii of curvature (r ₁ , r ₂ ) of the ridge lines (K _l , K ₂ ) lies on the central transverse axis (M) of the side wall (8) and this transverse axis (M) of the side wall (8) having the tooth edge (20) is a line of symmetry for this tooth edge. 7. The packaging box according to at least one of claims 1 to 6, characterized in that the end of the front in the pulling direction (x) comb-line (K ₂₎ of the side wall (8) provided on the longitudinal edge (19) and the vertex (Z) of the The tooth base of the base line (S) which defines the tooth valleys is arranged on the transverse axis (M) at a distance (e) from the adjacent box edge (7), the side length (i) of the packaging box (1, 31) preferably being approximately 20 times the distance ( e) and the height (h) of the side wall (8) more than twice the distance (e). 8. Packaging box according to at least one of claims 1 to 7, characterized in that the tear-off edge (20) containing the side wall (8) of the packaging box (31) is assigned a cutting strip (33), which by at least one predetermined tear line (34) or. Like. In a cover flap (13 _i ) and a pull strip (36) is designed to be separable, the pull strip being fixed to the packaging box before use, and / or that the height (h ₁ ) of the cover flap (13 _{1 is} shorter than the height (h) of the tear-off edge (20) containing side wall (8), so that the cover strip (12) of the packaging box (31) at least the maximum diameter of one the transparent film (3) formed film roll (3) is designed to be applied. 9. Packaging box according to claim 8, characterized in that the cover flap (13 _i ) near its free edge (34 _i ) has at least one adhesive layer (45 _h ) with a permanent free adhesive surface, and / or the adhesive layer (45 _h ) both on the Cover flap (13 _i ) and on the tension strip (36) is fixed and is divided at the predetermined tear line (34) by a separating cut (47) or the like. 10. Packaging box according to at least one of claims 1 to 9, characterized in that the adhesive layer (45 _h ) is part of a double-sided adhesive strip (45) and spanned by a protective strip (46), which is optionally with that on the pull strip (36) fixed section (45) of the double-sided adhesive strip (45) is firmly connected. 11. Packaging box according to at least one of claims 1 to 10, characterized in that the adhesive layer (45 _h ) arranged on the outside of the cover flap (13 _i ) in the use position of the packaging box (31) with which the tear-off edge 20) has side wall (8) limited the guide slide for the transparent film (3) and / or the Adhesive layer (45 _h) at a stop-forming conformation of the lower edge is provided _(34.) Of the cover flap (13 _i) (50), where appropriate, their cover strip (12) is at least made of a restoring force generated upon deformation of material. 12. Packaging box according to at least one of claims 1 to 11, characterized in that its blank (30) has both the four side walls (8, 4, 9, 12) as parallel strips separated by crease lines (7, 14) and on one the first side wall (8) distant crease line (15) a strip-shaped cover flap (13), the height of which corresponds approximately to that of the side wall (8) and the length of which is slightly shorter than the length (i) of the adjacent side wall (12).

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