DE102007044829B4 - Packaging bag with tear-open - Google Patents

Abstract

Packaging bag with tear-open, comprising a front (1) and a back (2), which are at least partially cohesively connected together in their edge regions whereby a joining edge (3) of a predetermined edge width is determined and the Aufreißhilfe by a in the joining edge (3) formed opening notch (5) and two lines of weakness (6) are formed, which extend across the width of the packaging bag in a predetermined tear region respectively on the front side (1) and the back side (2) and the packaging bag in a bag top (10) and a bottom bag part ( 9), characterized in that the center line (7) of the opening notch (5) at an angle, hereinafter crack angle (α) called greater than 0 ° and less than 90 ° outside the opening notch (5) with a distance (a) to Notch tip in a point of impact (8) on the lines of weakness (6) impinges.

Description

The invention relates to a packaging bag made of a flexible single or multi-layer packaging material z. B. of paper, plastic and / or metal with a tear-open, which allows a defined tearing of the packaging bag.

A generic packaging bag is from the EP 587 392 A2 known.

The need for the defined tearing of a packaging bag is of particular importance when it comes to the package contents z. B. is a liquid, bulk or a variety of small parts, so that the contents of the package in an uncontrolled opening of the packaging bag can escape partially or completely and it is assumed that the consumer makes the opening without a tool by tearing by hand.

The packaging size and the packaging material of generic packaging bags is determined depending on the type and amount of the package contents and can be very different. Although these packaging bags may differ in terms of their shape, in the widest sense they are always packaging bags with a front and a back side, which are connected to one another in a cohesive manner in their edge region. The connection may already be given over a part of the edge area by a gag due to a folding of the blank for the packaging bag. The other parts of the edge region are connected to each other by gluing or welding over a predetermined edge width (hereinafter called joining edge).

In a vertical positioning or holding the packaging bag, including the consumer receives sufficient evidence by imprints on the packaging bag, a cavity is formed in the upper portion of the bag volume free of the contents of the package. In this area, the front and the back can be brought by compression at least partially to each other to plant. So that no packaging content is lost during tearing, the forming tear line, starting from the edge region adjacent to the cavity, may extend only over the regions of the front and rear sides delimiting the cavity. However, most materials will not always tear in the desired areas without tear-open.

Examples of generic packaging bags are mentioned below.

For packaging of building materials such. As cement is often used a two-layer packaging material, consisting of a bag interior facing plastic film, which only has the task to protect the contents of the package from moisture and the bag exterior zugewanden very tear-resistant robust paper layer, which both the net weight of the packaging content, here too can exceed 30 kg and safely withstood transport loads. The bag shape here is a typical bag shape, determined by a top, a bottom and two side edges. The side edges and often also the lower edge are formed here over tricks. The upper edge represents a joining edge with a usual edge width of about 1-4 cm.

Not so much the weight but hygiene requirements and a high shelf life for the contents of the packaging are the focus of packaging for the food industry. In particular, for beverage packaging, a majority of three-layer packaging materials are used, consisting of an outer printed paper or plastic layer, a metal layer and an inner plastic layer. The here usually rectangular bag shapes are often glued or welded together along all edges, d. H. The packaging has a circumferential joining edge, with a usual edge width of about 2-8 mm.

As outer packaging z. B. for individually packaged confectionery packaging material is often only a single-layer plastic film, the z. B. manufactured as a hose having a lower and an upper joining edge.

Basically, the packaging material is produced in sheets or sheets and assembled into individual blanks. The blanks are then folded or preformed, as well as successive edges welded or glued together, that a packaging bag is formed, which is completely closed after filling.

The result is always a joining edge by the packaging material is connected directly to each other over a predetermined edge width. The joining edge can be a peripherally closed edge or interrupted by gashes.

Of the practice are widely known packaging bags that have an I or V-shaped opening notch in a lateral joining edge.

Such a solution is z. B. also from the EP 494 582 B1 known.

To open the packaging bag can then be grasped on the joining edge on both sides of the opening notch and pulled apart. The crack is introduced in the kerf direction and should propagate through the packaging material in the kerf direction, which practically does not happen if the crack is not guided in this direction.

According to the DE 199 24 428 A1 a notch introduced crack strikes the material edge of a coating and is guided along that edge. This requires, in addition to the additional process step of the coating, additional layer material which must be mechanically reinforcing.

There are also known in practice solutions in which lines of weakness across the width of the front and / or the back of the packaging bag are formed, whereby the crack propagation is indeed performed, but the difficulty is to initiate the crack at the beginning of the line of weakness.

The introduction of an opening notch and a line of weakness that opens into the end of the opening notch seems to combine the advantages of both currently known in the practice of alternatives. However, to realize this in an industrial mass production is technologically very difficult, since both can not take place in one process, but the opening notch must be positioned exactly to the weak line.

In the prior art was with the EP 587 392 A2 found a solution that combines an opening notch in the edge region and a guided across the width of a packaging bag line of weakness.

The introduction of a line of weakness can be done practically only before folding or forming the packaging bag. Ideally, it is introduced into the web before it is singulated in blanks for the packaging bag.

Weakening lines are a partial material separation, a partial removal of material or an embossing along the line of the desired weakening line in question.

Partial material separation may be a depth cut not completely separating the material, e.g. B. made with a knife or a punch.

A partial material removal may be a non-completely separating groove or a perforation or slot line of partially or even completely penetrating perforations or slots or combinations thereof.

The introduction of an opening notch will take place practically only after the welding or gluing of the edge regions, while the depth of the notch may not be greater than the edge width of the formed joining edge. In order to meet the stated requirements, this process step would have to be controlled as a function of the position of the line of weakness. There would have to be means which detect the position of the weakening line in order to control signals derived therefrom as a control variable for the positional positioning of the packaging bag in relation to the opening notch working tool, which would be very expensive.

The invention is based on the object to provide a packaging bag with a front and a back connected by a joining edge, in which for crack initiation an opening notch is formed and has the guided crack propagation lines of weakness, the requirements for a precise position-related introduction of the opening notch to be weak to the lines of weakness.

This object is achieved by a packaging bag having the features of claim 1.

Advantageous developments are described in the subclaims.

Reference to the drawing, a packaging bag is explained in more detail below by way of example.

Show it:

1a a first embodiment in plan view

1b a material web with the blank for the first embodiment

1c a section from 1a

2 a second embodiment

3 a third embodiment

4 a fourth embodiment

5 a fifth embodiment

6 a sixth embodiment

7 a seventh embodiment

8th a packaging bag with triangular front and back

9 a packaging bag with additional bottom part

10 a packaging bag with different front and back

Inventive packaging bags have the same as the packaging bags known from practice a front side 1 and a back 2 on, which are at least partially welded or glued together in their edge regions. The glued or welded edge areas form joint edges 3 a predetermined edge width.

In 1a is a first embodiment of a packaging bag according to the invention in plan view of the front 1 shown. The front 1 and the back side behind it 2 have a rectangular shape and are over a circumferential joint edge 3 connected with each other.

A cut 4 for this packaging bag, presented in 1b is advantageously cut from a web of packaging material and has twice the width of the packaging bag. By folding along the midline become the front 1 and the back 2 Covering each other. The clef formed by the fold forms one of the two side edges. Connecting the other side edge and the bottom edge would be sufficient to provide a fillable packaging bag. In order to achieve a symmetrical overall impression or to grip the packaging bag circumferentially well, however, is usually also the edge area along the gape as joining edge 3 educated.

It is clear to those skilled in the art that the blank 4 also can be designed so that the front 1 and the back 2 over the lower edge or the upper edge can be brought to coincide. In the latter variant, a filling would then take place from below.

The shape of the two sides does not necessarily have to be rectangular or identical. So show next to the 1 to 7 in which the shape of the packaging bag is rectangular, at least in the tear-open area, z. B. the 8th a packaging bag with two equal triangular side surfaces, 9 a packaging bag having two equal trapezoidal side surfaces and a third bottom surface forming a round surface. For a packaging bag according to 10 the front is trapezoidal and the back is rectangular. A third surface forming a floor compensates for the different lengths of the front and the back.

• – eine Öffnungskerbe 5 in einem Fügerand 3 vorgesehen ist
• – über die Breite des Verpackungsbeutels verlaufend, genauer der Vorderseite 1 und der Rückseite 2, zwei Schwächelinien 6 vorhanden sind, die den Verpackungsbeutel in ein Beuteloberteil 10 und ein Beutelunterteil 9 unterteilen und
• – die Mittellinie 7 der Öffnungskerbe 5 unter einem Winkel größer 0° kleiner 90° (nachfolgend Risswinkel α genannt) außerhalb der Öffnungskerbe 5 mit einem Abstand a zur Kerbspitze in einem Auftreffpunkt 8 auf die Schwächelinien 6 auftrifft.

All embodiments of a packaging bag according to the invention have in common that

• - an opening notch 5 in a joining country 3 is provided
• - Running across the width of the packaging bag, more precisely the front 1 and the back 2 , two lines of weakness 6 are present, the packaging bag in a bag top 10 and a bag bottom 9 divide and
• - the center line 7 the opening notch 5 at an angle greater than 0 ° smaller than 90 ° (hereinafter called crack angle α) outside the opening notch 5 with a distance a to the notch tip in a point of impact 8th on the lines of weakness 6 incident.

The combination of an opening notch 5 with lines of weakness 6 in the manner described represents a Aufreißhilfe and is essential to the invention.

A particular advantage of this tearing aid is its simple manufacture. It is technologically easily possible, an opening notch 5 and the lines of weakness 6 with the given conditions, since the introduction of the opening notch 5 not exactly on the location of the already given lines of weakness 6 must be aligned. Especially if the opening notch 5 in the bag shell 10 it can change significantly from its nominal position to the weakening line 6 without this having a significant effect on the tear behavior. In 8th Examples of permissible position deviations are shown.

By spreading-spreading the at the opening notch 5 adjacent areas, as is known in practice, initiated a crack on the notch tip. The crack spreads from the notch tip uncontrolled running in the front 1 and the back 2 of the packaging bag, until it according to the invention on the lines of weakness 6 in a meeting point 8th incident. Strictly speaking, the spreading crack divides when leaving the joining edge 3 , ie at the end of the composite material between the front 1 and back 2 in two cracks. Because they run unchecked, they could also be in different impact points 8th on the lines of weakness 6 incident. However, in order to avoid unnecessarily complicating the description of the invention, it is intended to speak below of only one crack, which originates from the notch tip in an impingement point 8th on the lines of weakness 6 incident.

From there, the propagation of the tear along the lines of weakness becomes 6 guided, that is, the packaging bag is, apart from a negligibly short way, defined in a bag base 9 and a bag top 10 separated. The dividing line determines the forming one Opening edge of the bag base 9 , Through a selected line of weakening lines 6 forming the parting line, the opening edge for pouring out or pouring out the contents of the package can be formed advantageously.

The lines of weakness 6 need in their line on the front 1 and on the back 2 not be identical. Also, the distance a and the impact point 8th , related to the front 1 or the back 2 , not be identical. However, in order to avoid unnecessarily complicating the description of the invention, it should be assumed that the line is congruent, which is the same distance a and the same impact point 8th on the front side 1 and the back 2 entails. For the Aufreißverhalten an identical lines is advantageous because both lines of weakness 6 should be separated simultaneously with an acting tearing force.

Below, some advantageous parameter variations of a packaging bag according to the invention are shown.

In essence, the positioning of the opening notch 5 , the opening angle and the depth of the opening notch 5 , the lines of the line of weakness 6 and their execution, the crack angle α and the distance a be executed differently.

The opening angle of the opening notch 5 has only meaning insofar that the opening notch 5 is visually perceptible at a larger opening angle. To fulfill its function, the opening notch 5 also be limited to a narrow slot.

The depth of the opening notch 5 must be chosen so that the notch tip is still completely in the joining edge 3 lies. For an opening notch 5 whose midline 7 perpendicular to the edge of the joint 3 This means that the depth of the opening notch 5 smaller the edge width of the joining edge 3 is. The opening notch 5 However, it is at least so deep that the packaging material up to the point of impact 8th on lines of weakness 6 can be separated with a suitable tearing force.

For the tearing behavior, the crack angle α should be as small as possible. Although the safety of the impact of the crack on the lines of weakness increases 6 when the crack angle α is larger, but at a small crack angle α, the component of the tearing force is directed toward the line of weakness 6 larger, the smaller the crack angle α. Preferably, the crack angle α should therefore be greater than 10 ° and less than 45 °.

The distance a should be as small as possible. However, it should be considered here, if it is too small, that then position deviations of the opening notch 5 from their nominal position can lead to the midline 7 already in the opening notch 5 coincides with the nominal line. A rift spreading from the curb tip would then not affect the lines of weakness 6 to meet.

• – eine kontinuierliche Schnittlinie einer konstanten oder sich ändernden Schnitttiefe,
• – eine Linie von durch Stegen getrennten, das Material durchdringenden oder nicht durchdringenden Schlitzen oder Perforationen bzw. Kombinationen hiervon,
• – eine Prägelinie oder
• – eine Linie entlang der das Verpackungsmaterial veränderte Materialeigenschaften aufweist

sein.The lines of weakness 6 can be made by any known material weakening that can be performed along a line. In particular, a weak line can 6

• A continuous cutting line of a constant or changing cutting depth,
• A line of web-separated, material-penetrating or non-penetrating slots or perforations or combinations thereof,
• - an embossed line or
• - A line along the packaging material has changed material properties

be.

In the 1 - 10 are the lines of weakness 6 each shown as a dashed line, which should be a representation of all the embodiments mentioned.

As tools for the production conventional tools for material separation, material removal or material modification can be used.

Particularly suitable appears to be a laser. The possibilities of selecting a laser with a suitable wavelength for each packaging material, the adaptation of the laser parameters to the desired material weakening and variable management of the laser radiation z. B. via a robotic arm or a scanner make the laser the predestined tool and a lasered line of weakness as a preferred embodiment for a line of weakness 6 ,

The lines of weakness 6 divide the packaging bag into a bag bottom 9 and a bag top 10 , With the complete rupture of the packaging bag is the bag top 10 from the bottom of the bag 9 separated and the contents of the package should be completely in the bag bottom 9 are located.

The course of the lines of weakness 6 is preferably rectilinear, angled or curved designed, with changes in direction should be as steady as possible.

In the in the 1a - 1c shown first embodiment of a packaging bag have the lines of weakness 6 an angled line that corresponds to three edges of the circumference of an isosceles trapezoid. The opening notch 5 is in the joining area 3 placed adjacent to a side edge, the centerline 7 is perpendicular to the side edge. In the point of impact 8th closes the direction of the line of weakness lines 6 with the side edge and so with the center line 7 a crack angle α of greater than 0 ° and less than 90 °, here by way of example of about 45 °. The distance a is chosen such that an over the opening notch 5 initiated crack outside the joining edge 3 on the lines of weakness 6 incident. If the distance a is chosen too large, there is a risk that the propagating rift, even before it hits the lines of weakness 6 impinges, uncontrolled in the bag base 9 spreads and a defined opening is thus no longer possible.

At an in 2 In the second embodiment shown, the distance a is reduced to increase the certainty that an initiated crack is actually on the lines of weakness 6 meets and does not run away uncontrolled before. The impact point 8th is still within the joining country 3 , This ensures that the leadership of the propagating tear still within the joining margin 3 starts. The lines of the weak line 6 indicates instead of an abrupt change of direction according to 1a a constant angle change by rounding the angular lines.

In the 3 The third embodiment shown, as well as all the embodiments described below, differs from the first two in that the opening notch 5 not within the bottom of the bag 9 but within the bag top 10 is introduced.

This has the advantage of having a crack extending from the notch top of the opening notch 5 completely independent of the distance a in each case on the lines of weakness 6 incident.

In this third embodiment, the lateral edge regions are not as joining edge 3 trained, but limited exclusively by tricks. The packaging bag is here over its length, as shown, on the back 2 locked. The opening notch 5 is located in the junction 3 , adjacent to the top edge of the packaging bag.

An in 4 illustrated fourth embodiment shows a sinusoidal line shape of the lines of weakness 6 , This will be the open edge of the bottom bag part 9 (Bag opening) designed so that the valley of the sinusoid in the front 1 and the back 2 Pourer shapes. Since the spouts are exactly opposite each other in the circumference of the bag opening, a liquid content of the package will be emptied exclusively via one of the spouts, if this is kept to a minimum.

At the in 5 The fifth embodiment shown is the line trace of the lines of weakness 6 again a sine wave, which is opposite to the in 4 shifted by half a period, so that the lines of weakness 6 to the side edges in a valley leak. Again, the valleys can serve as a spout, in particular that of the opening notch 5 opposite. The opening notch 5 is here again in the joining country 3 introduced, adjacent to a side edge and is still in the bag top 10 ,

Such an embodiment appears to be particularly advantageous because it passes through the opening notch 5 in the bag shell 9 the safety gives that crack to the line of weakness 6 impinges, the contents of the package can be emptied comfortably and the consumer in the usual way can tear the packaging bag starting from one side edge ago.

The advantage of a sinusoidal lines or other periodic lines is also in their simple feasibility z. B. by laser scanner.

In the 6 . 7 and 8th Embodiments are shown in which the lines of the lines of weakness 6 corresponds to a straight line. So that the lines of weakness 6 and the midline 7 the opening notch 5 nevertheless meet at a crack angle α, is in the in 6 shown sixth embodiment, the opening notch 5 placed on a corner, the joining edge 3 here limited was formed broader.

In the in 7 The seventh embodiment disclosed was the opening notch 5 introduced obliquely to the side edge, ie the center line 7 is not perpendicular to the side edge.

In the in 8th shown embodiment, as already explained, the front 1 and the back 2 a triangular area, which is why an opening notch introduced perpendicular to the side edge 5 in a crack angle α to a guided over the width of the packaging bag straight line of weakness 6 incident. The crack angle α corresponds in such a solution equal to the acute angle of the triangle, here 35 °.

The smaller the crack angle α is, the better the crack is in the line of weakness 6 reconciled.

LIST OF REFERENCE NUMBERS

1

front

2

back

3

joining edge

4

cut

5

opening notch

6

weakness line

7

Centerline of the opening notch

8th

of impact

9

Bag bottom

10

Bag shell

α

crack angle

a

distance

Claims (11)

Packaging bag with tear-open, comprising a front side ( 1 ) and a back ( 2 ), which are at least partially connected cohesively in their edge regions together whereby a joining edge ( 3 ) of a predetermined edge width is determined and the Aufreißhilfe by a in the joining edge ( 3 ) formed opening notch ( 5 ) and two lines of weakness ( 6 ) is formed over the width of the packaging bag in a predetermined tear region each on the front ( 1 ) and the back ( 2 ) and place the packaging bag in a bag top ( 10 ) and a bag bottom ( 9 ), characterized in that the center line ( 7 ) of the opening notch ( 5 ) at an angle, hereinafter called crack angle (α), of greater than 0 ° and less than 90 ° outside the opening notch ( 5 ) with a distance (a) to the notch tip at a point of impact ( 8th ) on the lines of weakness ( 6 ). Packaging bag according to claim 1, characterized in that the front side ( 1 ) and the back ( 2 ) have a rectangular shape at least in the tear area and the opening notch ( 5 ) is formed on one of the side edges, wherein the center line ( 7 ) of the opening notch ( 5 ) perpendicular to the side edge and the direction of the line of the lines of weakness ( 6 ) at the point of impact ( 8th ) with the side edge an angle greater than 0 ° smaller than 90 °. Packaging bag according to claim 2, characterized in that the line of the weakening lines ( 6 ) represents an angled straight line. Packaging bag according to claim 2, characterized in that the line of the weakening lines ( 6 ) represents a sinusoid. Packaging bag according to claim 1, characterized in that the front side ( 1 ) and the back ( 2 ) have a rectangular shape at least in the tear area and the opening notch ( 5 ) is formed on one of the side edges, wherein the center line ( 7 ) of the opening notch ( 5 ) at an angle greater than 0 ° is less than 90 ° to the side edge and the line course of the lines of weakness ( 6 ) represents a straight line. Packaging bag according to claim 1, characterized in that the front side ( 1 ) and the back ( 2 ) at least in the tear-open area in the shape of an isosceles triangle and the opening notch ( 5 ) is formed on one of the side edges, wherein the center line ( 7 ) of the opening notch ( 5 ) perpendicular to the side edge and the direction of the line of the lines of weakness ( 6 ) at the point of impact ( 8th ) with the side edge an angle greater than 0 ° smaller than 90 °. Packaging bag according to claim 1, characterized in that the front side ( 1 ) and the back ( 2 ) at least in the tear-open area in the shape of an isosceles triangle and the opening notch ( 5 ) is formed on one of the side edges, wherein the center line ( 7 ) of the opening notch ( 5 ) at an angle greater than 0 ° is less than 90 ° to the side edge and the line course of the lines of weakness ( 6 ) represents a straight line. Packaging bag according to one of claims 1-7, characterized in that the opening notch ( 5 ) in the bag top ( 10 ) is provided. Packaging bag according to one of claims 1-8, characterized in that the impact point ( 8th ) within the joining margin ( 3 ) lies. Packaging bag according to one of claims 1-9, characterized in that the crack angle (α) greater than 10 ° is less than 45 °. Packaging bag according to one of claims 1-10, characterized in that the line of weakness ( 6 ) is a lasered line.

Images