FR2795051A1 - Cardboard blank with tear-off wall for packaging crate has flaps forming bottom, top and side walls joined by pre-cut junction lines, and tear-off portions join side walls to bottom - Google Patents

Abstract

The packaging crate is made from a cardboard blank comprising a first vertical wall (2) connected by pre-cut junction lines (6-9) to the bottom, top and adjacent side walls. The vertical wall opposite the first wall is fixed to the bottom wall by a tear-off portion (33). The side walls adjacent to the first wall are fixed to the bottom wall by pre-cut tear-off portions (28,29). The crate walls are formed by flaps (2-5).

Description

<B> BODY, FLAN IN CARDBOARD WITH ZONE </ B> ARRACHABLE, <B> AND BLADE </ B> PERFORANTE <B> FOR </ B> PREDECTING <B> OF SUCH A ZONE </ B> The present invention relates to a packing case made of cardboard or corrugated cardboard comprising at least one line or tear-off zone.

It also relates to a blank to obtain such a packing box and a perforating blade for partial pre-cutting of such a line or tear-off zone.

It finds a particularly important application, although not exclusive, in the field of packaging for rigid products (jars, boxes ...) or semi rigid (bags ...), to easily present the products outside their transport packaging in an immediate, clean and attractive way, especially on the shelves of department store shelves.

Cardboard packages are already known for which there are provided tear-off or tear-off zones to perform certain functions, such as the tearing of the cardboard along a preferential path, and this in particular to separate a package into several parts or to open flaps.

These tearing zones are obtained by perforating the dotted cardboard with cutting blades called perforating nets. Dotted lines are defined by a regular alternation of perforated lines called cutters and non-perforated lines called attachment points.

The distance between two attachment points, in other words the cutting length, is called D1, while the distance between two cutting nets, in other words the length of an attachment point, is called D2.

Thus commonly denotes a perforating profile by a series of two digits corresponding to D1 and D2, separated by a point. The values D1 and D2 are always constant on the same cutting line.

For example, a net 8.3 will consist of an alternation of cuts of 8 mm in length and attachment points of 3 mm in length.

In some cases, if the path followed by the dotted line is also to be used as a folding line, these threads may also have a so-called raking function, that is to say between the perforations, the attachment points are crushed by deeper threads to facilitate subsequent folding around the line concerned.

As well as the blades or nets of simple cut or that the nets of ramage, the perforating blades are generally made out of steel, and are enchased on part of their height in a form of wood which ensures their rigidity with the lateral deformations during the put pressure on the cardboard to cut.

The difficulty in choosing a net is to select the one that allows easy, fast and clean pulling by the operator while avoiding an accidental breakage of attachment points by any other cause.

Thus, depending on the nature of the paper weight and the thickness of the corrugated board, the skilled person will be led to vary the values Dl and D2 to find the best compromise possible.

The higher the value of D2, the greater the energy required for pulling out.

Likewise, the lower the value of D1, the more tear-off points over a defined distance, and the higher the energy.

However, beyond a certain value of D2, the risk is that the tear does not follow the planned path, but on the contrary it deviates, greatly degrading the appearance of the cut.

for example, the graph of FIG. 1 shows the variation of the tearing force of an attachment point as a function of the length of the point of attachment in millimeters for a given type of cardboard.

The pulling zones of the prior art do not always achieve a satisfactory compromise between ease of pulling and resistance.

The present invention aims to provide a box and a blank better than those previously known to meet the requirements of the practice in particular that it allows to guarantee better than previously a perfectly controlled cut, easy and 100% reliable, while allowing a optimized resistance of the area to be torn to prevent any accidental risk of tearing the fastening points, for example because of a shock on the weakened area or a violent movement of the products inside the packaging.

This improvement is particularly useful when it comes to perforations made around a full face of packaging, for which the risks of priming precut parts are important, especially on the middle of the edges of the face, or the effort is the highest.

For this purpose the present invention proposes in particular to create variable resistance zones on the same length of perforating net, this taking advantage of the fact that the tearing torque applied to the area to be torn is variable depending on the angle between the force applied and the wall with the points of attachment, and that the energy transmitted to the point of attachment is a function of the speed at which the movement is applied.

These variable zones of resistance are obtained by varying the distances D1 and D2 on the same net.

Thus, it will be possible to start a dashed line end with a large distance D1 and a small distance D2, so as to easily start cutting and reach a high speed towards the center of the dashed line, then approaching the center on gradually reduces D1 while increasing D2 to obtain a greater resistance to tearing, and finally D1 is increased while reducing D2 as we approach the other end of the dotted line.

The invention thus proposes a packaging box made of cardboard or corrugated cardboard comprising at least one partially pre-cut fold line forming a net having cut portions of length D1 separated in pairs by attachment points of length D2, characterized in that at least one of the lengths D1 and D2 varies along said thread.

In advantageous embodiments, one or more of the following provisions are also used: the net is of rectilinear shape; the net is of curvilinear shape or has at least one angle; - The net has a first zone with cut portions of a first length D1 so-called important, so as to easily initiate the cutting and achieve a high speed of tearing, followed by a second zone of length D1 ', smaller than D1, to obtain a greater resistance to tearing; -. the net has a first zone with tear-off points of a first so-called weak length D2, so as to easily start cutting and reach a high tearing speed, followed by a second zone of longer length D2 ', greater than D2, to obtain a greater resistance to tearing; the net comprises a third zone having cut portions of length D1 "larger than Dl ', and / or tear-off points of length <B> D2" </ B> of length smaller than D2', to decrease again resistance to pulling; - The partially precut line is a junction line between walls of the body; .

- The body has a wall connected to the other walls by partially precut lines, so that said wall is easily torn while allowing a good resistance of the body to shocks; The invention also proposes a blank for forming a box as described above.

It also proposes a cutting blade for material made of cardboard or corrugated cardboard, comprising a net having cutting portions of length D1 separated in pairs by hollow portions of length D2, characterized in that at least one of the lengths D1 and D2 vary along said net.

Advantageously, the net has a first zone with cutting portions of a first length D1 called important, followed by a second zone of length D1 ', smaller than Dl. Also advantageously the cutting blade is arranged to allow the formation of partially precut lines of the type described above.

The present invention will be better understood on reading the following description of embodiments given as non-limiting examples.

The description refers to the accompanying drawings in which - Figure 1 is a graph showing the variation of the pulling force of an attachment point for a particular type of carton.

- Figure 2 shows a cutting blade according to one embodiment of the invention and a packaging wall after cutting.

- Figure 3 shows a progressive profile cutting blade according to another embodiment of the invention.

- Figures 4 and 5 show two cutouts for obtaining a box according to one embodiment of the invention, namely a first forming tray cutout and a second cut forming the lid.

FIG. 6 shows a variant of the second cutout that can be used with the first cutout of FIG. 4.

FIGS. 7 and 8 show in perspective a box and its opening according to an embodiment of the invention corresponding to the cutouts of FIGS. 4 and 6. FIG. 1 shows a curve 1 giving the variation of the pulling force of an attachment point for a profile 10.D2, ie with Dl = length of the cutters of 10 mm, D2 = length of the attachment point (mm) on the abscissa and the breaking force (N) on the ordinate, for a carton corrugated grade PC 2T30C090 T140 and a total paperboard weight of 410g / mm2.

We see that for D2 = 3 mm, the force is 9.3 N, for D2 = 4mm, we have 12.6 N and so on.

From these values and that of other similar curves, the skilled person will be able to dose the pulling force as needed.

FIG. 2 shows a panel 3 of double-sided corrugated cardboard, for example 3 mm thick, according to one embodiment of the invention with a partially precut line 4, comprising a first zone 5 and a second zone 6.

Zone 5 comprises cut portions 7 of a first length D1, and attachment points 8 of a first length D2. The second zone 6 comprises cut portions 9 of a second length D1 'smaller than D1, for example twice as small, and attachment points 10 of the same length D2 as the attachment points 8.

Figure 2 also shows the straight cutting blade 11 having a thread 12 of shaped arranged to cut the partially pre-cut line 4 and fixed on a rigid support 13, removably to allow easy change. Figure 3 gives an enlarged side view of another embodiment of the cutting blade 14 according to the invention.

The blade comprises a rectilinear net which here comprises four zones, of progressive tearing difficulty, namely a first zone 15, easy tearing, a second zone 16 of easy tearing, a third and a fourth zone 17 and 17 ', difficult pulling without momentum.

The first zone 15 is provided with cutting portions 18 of length for example 15 mm, and rectangular recesses 19 to form the attachment points, of length 5 mm.

The second zone 16 comprises cutting portions 18 'of 10 mm and recessed portions 19 identical. The third zone 17 comprises cutting portions 18 "of a third length of 6 mm and hollow portions 19 always 5 mm, and finally the fourth zone 17 'has cutting portions 18" of 6 mm and portions hollow 19 'of 16 mm.

Figures 4 and 5 of cutouts show a set of blanks formed by a first blank 20 to form a tray comprising a central rectangular flap and two side flaps 21, each provided with two pre-cut portions 22 and 23, rectangular or substantially rectangular, of which 22 is located at one end of the tray and is free on three sides and the other 23 is free on two sides. The tray comprises a central lateral flap 24 connected to the corresponding flap by a pre-cut fold line according to the invention.

Similarly, the second blank 26 comprises three rectangular flaps 27, 28 and 29 connected to the corresponding panels 30, 31 and 32 by pre-cut fold lines 33.

A gripping port 34 is provided at the fold line with the central panel, which allows, when the box is closed and glued, to tear the whole of the front face of the box from a single block. The second cutout has a second set of rectangular flaps 27 ', 28', 29 'connected to the adjacent panels by normal fold lines on the other side.

FIG. 6 shows another embodiment of second cutout 35 which comprises in turn four rectangular panels 36 interconnected by third folding lines 37, 37 ', parallel and a set of rectangular flaps 38, 39, 40, 41 , identical two by two, one of which two 39 is provided to come in front of the package and is connected to the adjacent panel 36 by a fold line 42 pre-cut according to the invention.

Said adjacent panel is itself connected to its adjacent panels by pre-cut fold lines 37 'according to the invention.

Here again the front face formed by the panel 36 glued at the bottom to the central flap 24 of flap, for example by gluing lines 50, is fully tearable according to the arrow 51, taking into account the fold lines or pre-cut edges 52, 53 and 54 (see FIGS. 7 and 8), thanks to the handle 55.

The box of FIGS. 7 and 8, formed from the blanks corresponding to FIGS. 4 and 6, allows disbudging only by horizontal movements of the tray and the upper part, only the products contained in the box remaining on the shelves or the support of presentation of the store.

When opening the box, it is possible to tear the panel 51 only connected to the rest of the box by fold lines 52prédécoupées according to the invention As it goes without saying and as it also results from the foregoing, the present invention is not limited to the embodiments more particularly described. On the contrary, it embraces all variants, especially those where the boxes are obtained by winding around a mandrel, such as those where the two blanks are folded and glued flat on one another, or where the blanks are tunneling said set already bonded through said pre-cut portions. Packing box made of cardboard or corrugated cardboard comprising at least one partially pre-cut fold line forming a net having cut portions of length D1 separated in pairs by attachment points of length D2, characterized in that at least one of the lengths D1 and D2 varies along said thread.

2. Case according to claim 1, characterized in that the net is of rectilinear shape.

3. Case according to claim 1, characterized in that the net is of curvilinear shape or has at least one angle; 4. Box according to any one of the preceding claims, characterized in that the net has a first zone with cut portions of a first length D1 said important, so as to easily initiate the cutting and achieve a high speed of tearing followed by a second zone of length D1 ', smaller than D1, to obtain a greater resistance to tearing.

Box according to one of the preceding claims, characterized in that. the net has a first zone with tear-off points of a first so-called weak length D2, so as to easily start cutting and reach a high tearing speed, followed by a second zone of longer length D2 ', greater than D2,

Claims (1)

<U> CLAIMS </ U> to obtain greater tear resistance. 6. Box according to any one of the preceding claims, characterized in that the net comprises a third zone having cut portions of length Dl "greater than D1 ', and / or tear points of length D211 of longer length. small as D2 ', to reduce again the tear resistance 7. Case according to any one of the preceding claims, characterized in that the partially precut line is a junction line between walls of the box 8. Case according to according to any one of the preceding claims, characterized in that the box comprises a wall connected to the other walls by partially precut lines, so that said wall is easily stripped off 9. Blank for forming a box according to any one of the claims. 10. Cutting blade for cardboard sheet or corrugated board material, comprising a net having portions of section of length D1 separated in pairs by hollow portions of length D2, characterized in that at least one of the lengths D1 and D2 varies along said thread. 11 blade according to claim 10, characterized in that the net has a first zone with cutting portions of a first length D1 said important, followed by a second zone length Dl ', smaller than D1. 12. Blade according to any one of claims 10 and 11, characterized in that the cutting blade is arranged to allow the formation of partially precut lines for a box according to any one of claims 1 to 8.