EP4166715A1 - Packaging material and banderole made therefrom - Google Patents

Abstract

Packaging material (1) consisting of an unbleached kraft paper with a kappa value according to ISO 302:2015 between 38 and 60 as base paper, the kraft paper being made from at least 90% primary cellulose and a basis weight according to ISO 536:2019 between 65 g/m ² and 170 g/m², which packaging material has an elongation at break ratio MD/CD according to ISO 1924-3:2005 of ≥ 1.1, a breaking length in the machine direction according to ISO 1924 -3:2005 of ≥10 km and has a tear propagation resistance index in the transverse direction according to ISO 1974:2012 ≥ 16.0 mN.m²/g, as well as methods for its production, a banderole made therefrom and use of packaging material. (Fig.1)

Description

The present invention relates to a packaging material consisting of an unbleached kraft paper with a kappa value according to ISO 302:2015 between 38 and 60, preferably between 40 and 58 as the base material, the kraft paper being made from at least 90% primary pulp and having a basis weight according to ISO 536:2019 between 65 g/m ² and 170 g/m ² , as well as a banderole made from such a packaging material, a method for producing the same and a use of the packaging material.

Unbleached kraft paper is widely used as a packaging material because it has high resistance to tearing and, moreover, also has good stability to exposure to moisture and chemicals. Kraft paper is also easily printable, regardless of whether it is bleached or unbleached, so that a consumer of the packaged goods can see the necessary information printed directly on the packaging. A typical application of kraft paper and in particular unbleached kraft paper is its use in the manufacture of sacks for packaging a wide variety of materials, such as building materials, sharp-edged materials, food, toys or the like. In the packaging sector, however, there is not only the shape of the packaging which the goods to be packaged are completely wrapped in the packaging paper, e.g. B. sacks closed on all sides, but it is often possible to surround goods to be packaged or goods to be sold in a bundle with a kind of loop on which information about the content, possibly the shelf life or the like., Often also brand names are printed. Such loops are often also used to provide a cohesion of a plurality of similar or different related goods to be packaged and, for example, in the clothing sector, several goods, such as a plurality of T-shirts, socks or the like, are often simply surrounded by wrapped in a bow or banderole. It is essential for the packaging material from which such a loop is made that it tightly encloses the goods to be packaged or enclosed, so that the loop cannot be pulled down unintentionally, one or more of the products surrounded by the loop cannot fall out or On the one hand, it is possible and furthermore guaranteed that the goods to be surrounded by the loop can be inserted into the loop without being damaged and, on the other hand, the loop surrounding the goods does not tear or get damaged in any other way when it is inserted in this way or during subsequent transport, handling or the like becomes.

In the same way, it is often necessary to provide tubular packaging materials in which compressible or resilient objects can be placed at their strongest must be packaged in a compressed form, on the one hand to keep the space required for this packaging as small as possible and on the other hand to ensure that the packaged goods are not unnecessarily often compressed and decompressed during transport, which could lead to material fatigue. In this context, it seems particularly important that the packaging material is not stressed beyond its stretching capacity and tears by the tensile stress exerted by the resilient goods packed in it, or that the tubular packaging material is not damaged when the goods to be packed are inserted. Plastic foils or tapes, which can be produced in different configurations and can also be produced adapted to the respective requirements, have been considered to be best suited for this to date. For environmental reasons, efforts are being made to replace plastic packaging with packaging made from renewable raw materials as far as possible. Recently, there has been increased research into producing special papers, in particular kraft papers, which meet a wide variety of requirements in terms of durability, stretchability, moisture resistance and the like, in order to replace plastic packaging. Here, in particular in cases where closed tubes or loops have to be used as packaging materials, there is the problem that packaging made of paper, for example, is produced from a flat paper web, which web has to be glued or otherwise closed in some way to form the ring or tube. If this closure is only closed after the goods to be packaged have been inserted, the time it takes for a formed adhesive point to harden or dry is sometimes too high for mass production, so that, analogously to plastic packaging, this tube, ring or loop is necessary form before inserting the products to be surrounded by it. So that products can be inserted into such a tube, ring or loop without destroying the same or the same, such a packaging material or packaging paper must not only have excellent stretchability in the radial direction, ie in the circumferential direction of the ring or loop, but may also especially when inserting the objects, do not tear at the edges.

The present invention therefore aims to provide a packaging material made of an unbleached kraft paper that does not tear both in the machine direction and in the cross-machine direction under great stress, in particular a stress that stretches the paper, and is or remains sufficiently elastic or resilient over time that the items packed in it cannot fall out even after a long period of time due to a loss of tension or elasticity in the packaging material.

To solve this problem, the packaging material according to the invention is essentially characterized in that it has an elongation at break ratio MD/CD according to ISO 1924-3:2005 of ≧1.1, a tearing length in the machine direction according to ISO 1924-3:2005 of ≧10 km and that a tear propagation resistance index in the transverse direction (CD) according to ISO 1974:2012 is ≥ 16.0 mN.m ² /g. By having the unbleached kraft paper of the packaging material with an elongation at break ratio MD/CD according to ISO 1974:2012 of ≥ 1.1, it is ensured that its stretchability in the machine direction (MD) is greater than that in the transverse direction and the packaging material is therefore not only in MD and CD is extensible, but can be subjected to a greater change in length in one direction than in the other without having to fear destruction, in particular tearing, of the packaging material.

The fact that the elongation at break ratio MD/CD according to ISO 1974:2012 is ≥ 1.1 also ensures that objects that do not have a homogeneous or even and smooth surface can be packaged safely and reliably in this packaging material based on unbleached kraft paper because the paper, substantially after returning to its original shape from its expanded shape caused by the insertion of the goods, tightly encloses the packaged goods on all sides and is also able to securely and reliably hold goods with uneven surfaces. At the same time, the elongation is sufficiently large so that the products can be inserted into the paper without damaging it, in particular into tubular sleeves formed from this paper, and it is also ensured that the paper returns to its original position after the materials have been inserted and stretched Form is returned and the packaged objects tightly encloses, so that falling out of packaged objects from, for example, tubular or ring-shaped packaging from the packaging material according to the invention need not be feared. Furthermore, it has been shown that with an elongation at break ratio MD/CD according to ISO 1974:2012 of >3, no further improvement in the properties of the packaging material required for packaging heavy objects can be achieved.

The fact that the tearing length in the machine direction according to ISO 1924-3:2005 is ≥ 10 km also ensures that the machine strength in the longitudinal direction of the packaging material is so great that even if, for example, tubular or ring-shaped packaging was made of it, too non-flexible objects can be placed inside this so-formed packaging material without fear of accidental tearing of the kraft paper. Furthermore, since the tear propagation resistance index in the transverse direction according to ISO 1974:2012 is ≥ 16.0 mN.m ² /g, it is ensured that a tearing of a free edge of the packaging material is not to be feared even in the case of unintentionally high loads on the edge of the packaging material and in particular when tubular or ring-shaped products are made of this packaging material, such as loops or banderoles, when the goods to be packaged are inserted Tearing of the packaging material and thus destruction of the packaging need not be feared.

Because the packaging material is designed in such a way that a tear propagation resistance index in the transverse direction (CD) according to ISO 1974:2012 is ≥ 16.0 mN.m ² /g, the packaging material, which essentially consists of unbleached kraft paper, can also be subjected to high stress at its edges, without fear of the paper tearing or tearing further from the edge to the middle. Finally, it can be prevented that even a small tear should be formed in the packaging material, this does not unintentionally enlarge.

In the context of the present invention, the term “packaging material” is understood to mean essentially unbleached kraft paper, which can optionally be coated on one or two sides. Furthermore, it may have one or more plies of the kraft paper.

According to a further development of the invention, the packaging material is designed in such a way that it contains at least 90% primary cellulose, containing at least 80%, preferably at least 85%, in particular at least 88% cellulose with an average length-weighted fiber length according to ISO 16065-2:2014 between 2.0 mm and 2.9 mm and less than 5%, preferably less than 4.5%, in particular less than 4.2% fillers and cationic starch and other processing aids. Because the packaging material is at least 90% primary cellulose, containing at least 80%, preferably at least 85%, in particular at least 88% cellulose with an average length-weighted fiber length according to ISO 16065-2:2014 between 2.0 mm and 2.9 mm and less than 5 %, preferably less than 4.5%, in particular less than 4.2%, of fillers and cationic starch and other processing aids, it is possible to provide an unbleached kraft paper with an extremely tear-resistant structure and, in particular, excellent due to the narrow length distribution of the fiber lengths of the primary pulp used to achieve homogeneous paper properties in both the machine direction and the cross direction. Such unbleached kraft paper can also be used safely and reliably for the packaging of sharp-edged objects or heavy materials such as cement or beverage bottles because of its toughness and its ability to be (micro)creped in a Clupak line. By continuing less than 5%, preferably less than 4.5%, in particular less than 4.2% (the percentages given are always to be understood as percentages by weight in the context of the present invention) fillers and cationic starch and processing aids are included, it is possible at the same time to obtain strong but not overly stiff unbleached kraft paper in which high percentages of starch, particularly cationic starch, can be used due to the lignin and hemicelluloses retained in kraft paper and the associated high levels of negative charges. Since an unbleached kraft paper produced in this way is not overly stiff, but is extremely stretchable, it is possible, especially when loops, banderoles or tubes are made from this packaging material, to securely and reliably enclose the items packaged in it without having to fear that they will fall out slip out of the packaging material in an unintentional manner, whereby care must be taken when producing such tubes or loops that the unbleached kraft paper has greater extensibility in the winding direction of the loop than in the transverse direction of the loop.

According to a development, the packaging material can also consist of 100% primary cellulose. Because the packaging material, in particular the unbleached kraft paper, consists of 100% primary cellulose, it is possible to avoid negative influences on the end product, which for example come from recycled cellulose or from cellulose obtained from waste paper, even more reliably and, in particular, can be avoided as a result , a reduced strength or elongation at break of the packaging material, which is usually caused by waste paper or recycled pulp, can be avoided. In connection with the present invention, it is essential that in particular the elongation at break or the elongation at break ratio, the breaking length in the machine direction and the tear propagation resistance index in the transverse direction can be kept high and as constant as possible over time in order to provide consistent material properties, with which succeed in producing tubular packaging or banderoles in which heavy or sharp-edged objects can also be packaged and/or wrapped and stored for a long period of time without tearing or tearing of the unbleached kraft paper and deterioration of the product produced packaging is to be feared.

The excellent mechanical properties of the unbleached kraft paper, keeping the surface smoothness of at least one side of the kraft paper high and keeping the Bendtsen roughness low, and thus excellent printability to provide this at least one side of the packaging material. In the present context, an attempt is simultaneously made to make only one side, in particular the side facing away from the machine or "top side" of the paper, correspondingly smooth, in order to ensure adhesion to the inside of tubular or ring-shaped packaging, ie that of the "top side side facing away from the packaging material according to the present invention to make as large as possible to prevent a loss of the packaged objects by slipping out as possible.

According to a development of the invention, the packaging material is designed in such a way that the primary pulp consists of a mixture consisting of at least 80% softwood pulp, more preferably at least 90% softwood pulp, in particular at least 95% softwood pulp with an average length-weighted fiber length according to ISO 16065-2:2014 of at least 2.0 mm, preferably at least 2.2 mm and the remainder consists of hardwood pulp with a mean length-weighted fiber length according to ISO 16065-2:2014 of at least 1.0 mm. The predominant amount of softwood pulp with a mean length-weighted fiber length according to ISO 16065-2:2014 of at least 2.0 mm and the rest hardwood pulp with a mean length-weighted fiber length according to ISO 16065-2:2014 of at least 1.0 mm can be through the softwood pulp the strength properties and, due to the hardwood pulp, the smoothness of at least one side of the unbleached kraft paper can be positively influenced, and a targeted choice of the pulp composition can produce a packaging material with both excellent mechanical properties, in particular the elongation at break ratio, and sufficient smoothness, which makes good printability available , to be provided. Furthermore, with such a selection of the pulp mixture, in particular the high content of softwood pulp, it can be ensured that an unbleached packaging material produced in this way has a large tearing length in the machine direction, as a result of which a particularly resilient packaging material can be provided in which objects with a higher weight can also be packed can without the packaging necessarily having to have a bottom and/or top surface.

By, as corresponds to a development of the invention, the packaging material is designed in such a way that the primary cellulose is contained as ground, in particular high-consistency ground cellulose with a degree of grinding according to Schopper-Riegler in accordance with ISO 5267-1:1999 between 13 °SR and 20 °SR , it is possible to break up fiber agglomerates that are still present, such as stripping and splinters, whereby a uniform sheet or particularly homogeneous kraft paper can be formed, in which an optimized combination of flexibility of the fiber and tear propagation resistance index in the transverse direction can be achieved. Needless to say, high- and low-consistency milling of paper increases both the breaking length as well as the air permeability of the paper can be adjusted, although the latter is not important in the present case, especially with an optional application of coatings, since neither rapid filling of closed bags made of the packaging material according to the present invention is to be achieved, nor the Air permeability causes advantageous or negative properties for packaging made from the packaging material in any other way.

By, as corresponds to a development of the invention, the packaging material is designed in such a way that it has a tensile strength index in the machine direction according to ISO 1924:3: 2005 of ≥ 105 Nm/g, preferably at least 115 Nm/g, non-destructive packaging of heavy or sharp-edged objects in the packaging material according to the present invention. The tensile strength index according to the invention in the machine direction also ensures that, when producing, for example, tubular packaging or loop-shaped or banderole-shaped packaging from the packaging material according to the invention, it is possible to provide the packaging material with sufficient resilience, which means that even heavy objects can be fitted into such a packaging material Loop or banderole from the packaging material is certainly possible and, moreover, tearing of the material is not to be feared.

In the same way, as corresponds to a development of the invention, the packaging material has a TEA index in the machine longitudinal direction according to ISO 1924-3:2005 greater than 5.0 J/g, preferably greater than 5.5 J/g. Because the TEA index in the machine length direction is greater than 5.0 J/g, it is possible to provide a packaging material that is extremely elastic and stretchable without the packaging material breaking. The TEA index is understood as meaning the tensile rupture work index (“Tensible Energy Absorption Index)” in accordance with ISO 1924-3:2005.

In order to prevent the packaging material according to the invention from tearing or bursting from the edges to the center with certainty, the invention is developed in such a way that the packaging material has a bursting strength according to ISO 2758:2014 of greater than 750 kPa, preferably greater than 770 kPa, particularly preferably greater 800 kPa. According to the invention, the bursting strength is set or increased, inter alia, by a combination of the following measures: use of cellulose from softwood, a low filler content and a high proportion of, for example, cationic starch. Furthermore, the grinding, in particular low-consistency grinding, also has a positive influence on the bursting strength.

By, as corresponds to a development of the invention, the packaging material is designed in such a way that it has a wet strength index according to ISO 3781:2011 in the machine direction of at least 14.0 Nm/g, in particular 14.5 Nm/g, particularly preferably at least 15 0 Nm/g, the packaging material makes it possible in particular to provide tubular or ring-shaped packaging which is also suitable for use in a humid environment. Especially when, for example, food packaging or loops, which surround a plurality of foods or foods and hold them together, are made from the packaging material, contact with condensation, moisture or a damp environment cannot be avoided, so that high wet strength or a high wet strength index, but without having to use permanent wet strength agents, or large amounts thereof, in the manufacture of packaging material consisting essentially of unbleached kraft paper is desirable.

Surprisingly, such a high wet strength can also be achieved with a high dry base strength with the packaging material according to the present invention. In order to achieve high wet strength, it is usually necessary to use larger amounts of auxiliary materials, such as wet strength agents, which in turn cause problems when the packaging material to be produced, which essentially consists of unbleached kraft paper, causes problems. Since the dry strength in the packaging material according to the invention, which essentially consists of unbleached kraft paper, is ≧105 Nm/g, expressed by the tensile strength index in the machine direction, it is surprisingly possible to achieve sufficient wet strength in a very resource-efficient manner without or only by adding very small amounts of wet strength agents .

In the present case, wet strength agents are understood to be water-miscible polymer solutions in the processed state, which are primarily produced from polyamines and epichlorohydrin derivatives. Products based on urea-formaldehyde or melamine-formaldehyde are also conceivable as wet strength agents, but these are preferably no longer used for reasons of avoiding health risks. When the wet strength agents react with cellulose fibers, cross-linking forms between the fibers, which leads to increased water resistance of the corresponding paper produced in this way. However, the hydrophobic linkage formed in this way prevents a simple or successful recycling of a paper treated with these wet strength agents. A return of used packaging papers to a pulp cycle is therefore not possible or only possible to a limited extent through the use of high temperatures and/or additional chemicals and additives. It is thus desirable to keep the amount of wet strength agents used as low as possible, which surprisingly realizable with a paper or packaging material according to the invention.

The invention also aims to form or provide a banderole from the packaging material according to the present invention, with which banderole it is possible to pack or enclose a plurality of heavy, non-connected products and to transport them without tearing of the packaging material is to be feared.

To solve this problem, a banderole is provided according to the invention from the packaging material of the present invention, which is designed in such a way that it consists of a transversely closed, in particular flanged, glued, preferably double-glued, welded, stapled, sewn or riveted essentially paper web made from unbleached kraft paper, and that a machine direction of the paper web forms a circumferential direction of the banderole. The fact that the paper web is formed from a closed, in particular flanged, glued, preferably double-glued, welded, stapled, sewn or riveted paper web essentially made of unbleached kraft paper in the transverse direction makes it possible to achieve the greater elongation that the unbleached kraft paper has in the machine direction , in the circumferential direction of the banderole or the tubular packaging, so that due to the excellent stretchability of the packaging material in the machine direction, a plurality of objects when inserted into the banderole or in the packaging material glued to form a ring, the packaging material does not tear or tear further . Since it is thereby possible to enclose a plurality of objects with the banderole, it goes without saying that several objects of the same type or different among one another can be enclosed and held together without having to provide packaging that completely encloses the objects. By arranging the packaging material in the finished band in such a way that a machine direction of the packaging material forms a circumferential direction of the band, the elongation properties in the machine direction introduced by the manufacturing process of the packaging material can be used to ensure that objects to be packaged or enclosed using the elongation properties of the packaging material can be introduced into a banderole that has already been glued to form a ring, without the risk of the banderole tearing and are held firmly in this ring after they have been introduced due to the resilience of the packaging material.

By connecting the packaging material to form a ring or loop or banderole in such a way that it encloses a plurality of objects in the machine direction of the paper web, it is also possible to insert the plurality of objects into such a banderole without the banderole tearing in the transverse direction also longitudinally, nor at the edges of the banderole. Moreover, it goes without saying that such a banderole represents an extremely paper-saving type of packaging with which objects can be packaged and held together securely and reliably.

By enclosing at least two identical or different objects in the banderole, it is ensured that bundles of any size can be formed, which are simultaneously due to the elongation at break ratio MD/CD according to ISO 1924-3:2005 of ≥ 1.1 to about 3 and the tear propagation resistance index in the transverse direction according to ISO 1974:2012 of ≥ 16.0 mN.m ² /g can be reliably inserted into the banderole or the tubular product without the risk of the edges of the paper tearing or tearing out. Such a banderole can also be used to package heavy objects or objects that are long or tall compared to the width of the banderole without the risk of the banderole tipping over and subsequently tearing. This is because, due to the material properties of the packaging material, the objects can be tightly enclosed and therefore tearing and subsequent tearing of the banderole is not to be feared even if one or more objects tilt over.

In this case, the banderole can be designed in such a way that the plurality of objects are arranged in several rows, in a circle or forming a dense packing in the banderole. With such an arrangement of the enclosed objects, for example, conventional beverage packs comprising two, six or even twelve bottles can be surrounded by a band according to the invention or, for example, food products such as zucchini or bananas can be arranged in a band or, for example, several foam elements that are identical to one another, such as foam cushions or rods made of metal or wood are arranged inside such a banderole.

According to a development of the invention, the banderole is designed in such a way that it is subjected to tensile loads from the enclosed objects, in particular with a tensile stress that is less than an elongation at break in the machine direction (MD) measured according to ISO 1924-3:2005 of the paper web is. The tensile load or tensile stress on the items packaged inside such a banderole ensures that an item does not accidentally fall out of the banderole, which means that the remaining products can no longer be guaranteed to remain in place.

In order to provide sufficient extensibility of the packaging material or also to be able to provide sufficient resilience of the same, the packaging material is essentially designed in such a way that the elongation at break in the machine direction (MD), measured according to ISO 1924-3:2005, of the paper web is ≧8%. Kraft papers, which have an elongation at break of the paper web of ≥ 8% in the machine direction, have proven themselves in standard packaging materials, such as heavy-duty sacks and the like, which are subjected to heavy loads in MD, and surprisingly it has been shown that banderoles made from such a material in the Are able to hold products packaged therein safely and reliably due to the excellent resilience of this material without fear of the products slipping or falling out of the band or tearing or tearing of the band when the products are inserted.

A further object of the present invention is to provide a method for forming a band from the packaging material according to the invention, where, due to the conventional production methods, the problem essentially lies in the fact that a paper web has in principle greater elongation properties in the machine direction than in the transverse direction as a result of appropriate treatments . Although isotropic papers are already known which have the same properties in the longitudinal and transverse directions, these can only be produced to a limited extent on large paper machines and, in particular, these papers usually have at least slightly poorer properties in the transverse direction.

In order to be able to optimally utilize the favorable properties of the packaging material according to the invention with a banderole, the method according to the invention is designed in such a way that from a web of packaging material essentially consisting of unbleached kraft paper unrolled in the machine longitudinal direction, a length of the packaging material is cut off, the cut length of packaging material is pivoted through 90°, those two free edges of the cut length, which run in the machine cross direction when the web of packaging material is unwound, are folded over one another and closed to form a tube and that one of the closed tube Multiple bands are separated or prepared for separation, in particular perforated, scored or marked. Due to the non-existing possibility or economic futility of making cuts or a large number of cuts in the paper in the longitudinal direction of the machine in a running paper web on a paper machine, the method in Substantially guided in such a way that only a length of the packaging material is cut off from a rolling web of packaging material, which length essentially corresponds to the circumference of a banderole to be produced. In this case, of course, a certain excess length can be provided, which must be present as an overlap of the material when the layer of packaging material is subsequently closed to form a tube or, if appropriate, a single banderole. After cutting off the appropriate length, a tube can either be formed directly from the cut length, with the paper then being folded in such a way that in principle the transverse direction, i.e. the width of the web of packaging material, forms the circumferential length of the tube, or the cut off directly Piece of packaging material can be turned 90° and subsequently glued, crimped, riveted, sewn or the like to form a tube. In a last step, it is now necessary to separate appropriate pieces, which correspond to the width of the banderole, from the tube formed in this way. The detachment can be done by cutting, punching, tearing off and the like, for which purpose either perforations, marking lines, pre-punched areas or the like can be made beforehand, and depending on the application and end use of the banderole, this is carried out either directly or by the end customer . It makes sense that those pieces that form a large number of bands are not separated beforehand, since, for example, printing is in principle easier if larger areas can be correspondingly printed at the same time.

According to a further development of the method according to the invention, the method can be carried out in such a way that the pivoting of the cut length of packaging material by 90° before or after folding over one another and sealing those two free edges of the cut length which occur when the web of packaging material is unwound in the cross-machine direction run, is carried out. As stated, it is irrelevant here whether the pivoting of the cut length of the packaging material by 90° is carried out before or after the two free bands of the cut length are folded over one another to close them.

The packaging material according to the invention can, as corresponds to a development of the invention, be used as a banderole. It should also be mentioned that conventional bags and the like could of course also be made from this packaging material, but this is only possible due to the special material properties makes sense for high-performance products.

• Fig. 1 eine schematische Darstellung von möglichen Arten der Verbindung von einem Verpackungsmaterial gemäß der Erfindung zu einer Banderole bzw. Schleife; und
• Fig. 2 eine schematische Darstellung des Verfahrensablaufs zur Herstellung einer Banderole aus dem Verpackungsmaterial gemäß der Erfindung.

The invention is explained in more detail below using exemplary embodiments and drawings. In these show:

• 1 a schematic representation of possible types of connection of a packaging material according to the invention to a banderole or loop; and
• 2 a schematic representation of the process sequence for producing a banderole from the packaging material according to the invention.

In detail is in Fig. 1a ) shows a band or loop 1 schematically, which band 1 is designed such that two free ends 2, 3 of the packaging material forming the band 1 overlap and in the region of the overlap 4 at least one connection is formed.

With such a packaging material 1, which is designed in particular as a loop or banderole, it is thus possible to hold a plurality of objects that are identical or different in design to one another by the banderole 1 without, for example, additional plastic packaging that extends over the entire pack of the Items extends, must be used. The area of the connection 4 can have any type of connection, such as surface bonding (see Fig. 1b )), punctiform adhesions (see 1c )), or it can be any type of connection, such as sewing (see Fig. 1d )), brims, large-area gluing or the like. A banderole designed in this way is then pulled over the objects to be held together, as a result of which these are tightly and firmly held together due to the resilience of the material.

In Fig. 1b ) shows a perspective longitudinal view of an endless tube formed from the packaging material according to the invention, which endless tube 1 is intended for the formation of a plurality of banderoles 1. At the in Fig. 1b ) shown training are in turn the free ends 2, 3 of the packaging material arranged overlapping and the connection area 4, as shown by a dashed area, glued over the entire surface. The dashed lines 11 show in Fig. 1b ) possible dividing lines for detaching individual banderoles 1.

In 1c ) is an illustration of a continuous tube made of the packaging material according to the invention in a manner analogous to that in FIG Fig. 1b ) shown, where instead of a full-surface adhesion in the overlapping area 4 point-shaped adhesion points, which are arranged in particular in two rows offset from one another, were carried out. there is no need to hold on that of course any other type of gluing, be it in two individual gluing lines, one gluing line or the like can be selected.

In Fig. 1d ), in which also a representation as in Fig. 1b ) of the packaging material according to the invention has been chosen, it is shown that the free ends 2, 3 of the packaging material forming the endless tube are sewn to a second layer of packaging material 8, as indicated schematically by the seam lines 6.

With such banderoles 1, it is now possible to pack a wide variety of objects together so that they cannot be lost and, in particular, to ensure that tearing of the packaging material 8 is avoided even when heavy objects, such as metal rods or the like, are packed. If such a banderole 1 is pulled over objects to be packaged, in particular heavy or hard objects, it is possible, due to the resilience of the unbleached kraft paper forming it, in particular its elongation at break, tensile strength or also the tear propagation resistance index, to ensure that if a small tear in the packaging material 8, which forms the banderole 1, should have been formed, this does not tear further and, moreover, the banderole 1 formed in this way contracts after stretching to the extent that the objects packed in it can also be guaranteed to slip out after the packaging is complete. In addition, due to the special design of the packaging material 8, a certain static friction can also be exerted on the objects packed in it, which ensures that the objects are immovably received inside the banderole 1 and one or more of the objects is reliably prevented from slipping out. The static friction mentioned here can be exerted not only by the banderole 1, but also, for example, by the surface of the objects packaged therein.

In 2 , in which the reference numerals from 1 are retained, the process sequence for producing a banderole from the packaging material 8 according to the invention is shown schematically.

In 2 7 designates a roll of the packaging material 8, such as is rolled up onto a spool from the production, for example from a paper machine. The packaging material 8 is unrolled from the roll 7 of the packaging material 8 in the direction of the arrow 9, which arrow 9 also corresponds to the machine direction of the machine on which the packaging material 8 was produced, for example a paper machine. When a sufficient length of the packaging material 8 has been unwound, it is cut off along the width of the packaging material 8, as indicated by the broken line 10. In a second step, this cut length of packaging material 8 is turned by 90°, as indicated by arrow 11, in order to have the original machine direction 9 now arranged in the transverse direction of the cut piece of packaging material 8, as again indicated by arrow 9 is. The cut piece of packaging material 8 has a length L in the machine direction of the roll of packaging material 8, which essentially corresponds to the circumference of a banderole 1 to be formed from this packaging material 8, with either a slight excess length being selected depending on the subsequent method of connecting the packaging material 8 in order to be able to glue the ends over one another or, in principle, exactly the circumferential length of the banderole is selected if the connection is made by folding, stapling, sewing or the like. In a third step, a tube is formed from this severed length of packaging material 8, in which case any conventional tube forming method can be used, as indicated in the figure. In the present case, the tube is formed in such a way that the free ends 2, 3 of the packaging material 8 overlap by a distance or a length 4, so that the free ends 2, 3 can then be glued together, for example, in particular even glued twice to be able to The free ends of the packaging material 8 are here, as in the 1 denoted by the reference numerals 2 and 3 and the overlapping piece by 4, as for example in Fig Fig. 1a is shown. After the packaging material 8 has been glued, the tube produced in this way can either be printed or subjected to any further treatment, such as perforating, marking, punching or, in particular, cutting, in order to produce the banderoles 1 from the material according to the invention.

Needless to say, the second step of the process of folding the packaging material 8 by 90° can also be performed after the tube forming. In any case, the packaging material 8 must be connected to one another along the edges 2, 3 in order to have the favorable material properties, which result from the machine direction of manufacture, available in the circumferential direction of a finished banderole 1.

With regard to the optional method steps, such as printing, perforating or the like, it should be noted that these can be carried out before or after each step following the separation of the web of packaging material 8 from the cylinder. It can thus be advantageous to print the piece of packaging material that has been cut off immediately and only then to form a tube from the packaging material 8 .

The banderole or loop 1 can not only be designed in one color, but also printed in several colors, with company wordings, logos and the like. And moreover, it can have a one-sided or two-sided coating, for example to improve the moisture resistance of the packaging material 8. Finally, it can also have more than one ply of the unbleached kraft paper. In this case, it should be noted that the essential properties of the banderole 1 must not be changed and neither the elongation at break nor the bursting strength, the tearing length, etc. may be changed disadvantageously.

Finally, it goes without saying that a banderole 1 according to the invention can be used not only to hold heavy and hard objects or plastic cans together, but also, for example, to surround socks, or to connect food such as bananas, courgettes, cucumbers or the like. Goods or foodstuffs, boxes and the like packaged in cans, for example, can also be connected to one another.

Furthermore, the invention is explained in more detail by means of exemplary embodiments.

Example 1: Production of a packaging material based on unbleached kraft paper with a grammage of 82 g/m ² Process description:

An unbleached pulp consisting of 100% primary softwood pulp (mixture of spruce and pine) with a kappa number of 51 was first subjected to high-consistency beating with a beating capacity of 230 to 240 kWh/t, with a freeness of the pulp after high-consistency beating of 17 °SR was. This pulp was then subjected to low-consistency beating with a beating capacity of 90 to 100 kWh/t. The additives listed below were metered into the approach flow of the paper machine. Here, the pH was adjusted to a value of from 6.8 to 7.0 with aluminum sulfate, and cationic starch, with a degree of cationization DS of 0.03, was metered in in an amount of 17 kg/t paper dry as sizing agent alkenylsuccinic anhydrides were used in an amount of 0.8 kg/t dry kraft paper and 10 kg/t PAAE as wet strength agents. Furthermore, no fillers were added. The consistency of the pulp at the headbox was 0.19%. Dewatering was carried out on a Foudrinier wire section and with a press section with three nips, one of the presses being a shoe press, the line pressure on the three nips being 60 kN/m, 90 kN/m and 500 kN/m respectively (in the shoe press) fraud. Before the still damp paper was fed into the Clupak system, it was subjected to contact drying, conventional drying with the use of hot air at 167 °C, then pre-dried in a slalom dryer section and treated in a Clupak system with a differential speed of -7.9% and finally to dried to a final residual moisture content of 7.5%.

The kraft paper can be used as such for the production of ribbons or bands and the paper properties described in the table below were measured in this kraft paper.

The kraft paper thus produced had the following properties: Table 1: paper property standard Unit Direction Result grammage ISO 536:2019 gsm ² 82 tensile strenght ISO1924-3:2005 kN/m md 8.9 Tensile Strength Index ISO1924-3:2005 Nm/g md 109 tensile strenght ISO1924-3:2005 kN/m CD 5.4 Tensile Strength Index ISO1924-3:2005 Nm/g CD 66.3 elongation at break ISO1924-3:2005 % md 9.6 elongation at break ISO1924-3:2005 % CD 8.6 tensile work ISO1924-3:2005 J/ ^m2 md 578 tensile work ISO1924-3:2005 J/ ^m2 CD 405 Bendtsen roughness ISO8791-2:2013 ml/min top 867 Bendtsen roughness ISO8791-2:2013 ml/min bottom 1250 bursting strength ISO 2758:2014 kPa 781 wet strength index ISO 3781:2011 Nm/g md 15.2 Tear resistance index ISO1974:2012 mN.g/m ² md 14.2 Tear resistance index ISO1974:2012 mN.g/m ² CD 16.1 Elongation at break ratio ISO1924-3:2005 - MD/CD 1:12 tear length ISO1924-3:2005 km md 11.06

Example 2: Production of a packaging material based on unbleached kraft paper with a grammage of 130 g/m ² Process description:

An unbleached pulp consisting of 95% primary softwood pulp with a kappa number of 41 and 5% primary hardwood pulp with a kappa number of 40 was first subjected to high-consistency beating with a beating capacity of 190 to 210 kWh/t, a degree of beating of the pulp after the high-consistency beating was 19°SR and then this pulp was subjected to a low-consistency beating with a beating capacity of 70 to 80 kWh/t. The auxiliary materials were added in the approach flow of the paper machine. Here, the pH was adjusted to a value of 6.8 to 7.0 with aluminum sulfate, cationic starch, with a degree of cationization DS of 0.03, was metered in in an amount of 14 kg/t paper atro and as a size alkenylsuccinic anhydrides were used in an amount of 0.8 kg/t atro kraft paper. Glyoxalated PAM with 10 kg/t kraft paper atro was used as wet strength agent. Furthermore, no fillers were added. The consistency of the pulp at the headbox was 0.23%. Dewatering was carried out on a Foudrinier wire section and with a press section with three nips, one of which may be a shoe press, the line pressure on the three nips being 60 kN/m, 90 kN/m and 500 kN/m respectively (in the shoe press ) fraud. The kraft paper is pre-dried and then treated in a Clupak system with a differential speed of -8.6% and finally dried to a final moisture content of 7.5%.

The kraft paper can be used as such and the paper properties described in the table below were measured with this paper.

The kraft paper thus produced had the following properties: Table 2: paper property standard Unit Direction Result grammage ISO 536:2019 gsm ² 130 tensile strenght ISO1924-3:2005 kN/m md 16.2 Tensile Strength Index ISO1924-3:2005 Nm/g md 124.6 tensile strenght ISO1924-3:2005 kN/m CD 6.3 Tensile Strength Index ISO1924-3:2005 Nm/g CD 48.5 elongation at break ISO1924-3:2005 % md 10.3 elongation at break ISO1924-3:2005 % CD 8.5 tensile work ISO1924-3:2005 J/ ^m2 md 871 tensile work ISO1924-3:2005 J/ ^m2 CD 372 Bendtsen roughness ISO8791-2:2013 ml/min top 1420 Bendtsen roughness ISO8791-2:2013 ml/min bottom 1890 bursting strength ISO 2758:2014 kPa 812 wet strength index ISO 3781:2011 Nm/g md 16.1 Tear resistance index ISO1974:2012 mN.g/m ² md 12.1 Tear resistance index ISO1974:2012 mN.g/m ² CD 19.3 Elongation at break ratio ISO1924-3:2005 - MD/CD 1:21 tear length ISO1924-3:2005 km md 12.7

Example 3: Production of a packaging material based on unbleached kraft paper with a grammage of 130 g/m ² Process description:

An unbleached pulp consisting of 95% primary softwood pulp with a kappa number of 41 and 5% primary hardwood pulp with a kappa number of 40 was first subjected to high-consistency beating with a beating capacity of 190 to 210 kWh/t, with a Freeness of the pulp after high-consistency beating was 19 °SR and this pulp was then subjected to low-consistency beating with a beating capacity of 70 to 80 kWh/t. The auxiliary materials were added in the approach flow of the paper machine. Here, the pH was adjusted to a value of from 6.8 to 7.0 with aluminum sulfate, cationic starch with a degree of cationization DS of 0.03 was metered in in an amount of 14 kg/t paper dry and used as sizing agent Alkenylsuccinic anhydrides used in an amount of 0.8 kg / t Kraft paper atro. Glyoxalated PAM with 10 kg/t kraft paper atro was used as wet strength agent. Furthermore, no fillers were added. The consistency of the pulp at the headbox was 0.23%. Dewatering was carried out on a Foudrinier wire section and with a press section with three nips, one of which may be a shoe press, the line pressure on the three nips being 60 kN/m, 90 kN/m and 500 kN/m respectively (in the shoe press ) fraud. The kraft paper is pre-dried and then treated in a Clupak system with a differential speed of -8.6% and finally dried to a final moisture content of 7.5%.

The kraft paper can be used as such and the paper properties described in the table below were measured with this paper.

The kraft paper thus produced had the following properties: Table 3: paper property standard Unit Direction Result grammage ISO 536:2019 gsm ² 130 tensile strenght ISO1924-3:2005 kN/m md 16.2 Tensile Strength Index ISO1924-3:2005 Nm/g md 124.6 tensile strenght ISO1924-3:2005 kN/m CD 6.3 Tensile Strength Index ISO1924-3:2005 Nm/g CD 48.5 elongation at break ISO1924-3:2005 % md 10.3 elongation at break ISO1924-3:2005 % CD 8.5 tensile work ISO1924-3:2005 J/ ^m2 md 871 tensile work ISO1924-3:2005 J/ ^m2 CD 372 Bendtsen roughness ISO8791-2:2013 ml/min top 1420 Bendtsen roughness ISO8791-2:2013 ml/min bottom 1890 bursting strength ISO 2758:2014 kPa 812 wet strength index ISO 3781:2011 Nm/g md 16.1 Tear resistance index ISO1974:2012 mN.g/m ² md 12.1 Tear resistance index ISO1974:2012 mN.g/m ² CD 19.3 Elongation at break ratio ISO1924-3:2005 - MD/CD 1:21 tear length ISO1924-3:2005 km md 12.7

Example 4 Production of a packaging material based on unbleached kraft paper with a grammage of 161 g/m ² Process description:

An unbleached pulp consisting of 100% primary softwood pulp with a kappa number of 46 was first subjected to high-consistency beating with a beating capacity of 210 to 220 kWh/t, with a degree of beating of the pulp after high-consistency beating was 18 °SR and was then this pulp is subjected to low-consistency beating with a beating capacity of 70 to 85 kWh/t. The auxiliary materials were added in the approach flow of the paper machine. Here, the pH was adjusted to a value of 6.8 to 7.0 with aluminum sulphate, cationic starch with a degree of cationization DS of 0.05 was metered in in an amount of 12 kg/t of kraft paper atro and used as sizing agent Alkenylsuccinic anhydrides used in an amount of 0.8 kg / t Kraft paper atro. Furthermore, talc was added as a filler in an amount of 2 kg/t of kraft paper atro. The consistency of the pulp at the headbox was 0.25%. The drainage was carried out on a Fourdrinier wire section, such as a press section with three nips, the line pressure at the three nips being 60 kN/m, 80 kN/m and 80 kN/m respectively. The kraft paper was pre-dried, then fed into the Clupak system and subjected to a differential speed of -10.9%, then finally dried to a final residual moisture content of 8%.

The kraft paper can be used as such and the paper properties described in the table below were measured with this kraft paper.
The paper thus produced had the following properties: Table 3: paper property standard Unit Direction Result grammage ISO 536:2019 gsm ² 161 tensile strenght ISO1924-3:2005 kN/m md 19.1 Tensile Strength Index ISO1924-3:2005 Nm/g md 118.6 tensile strenght ISO1924-3:2005 kN/m CD 7.9 Tensile Strength Index ISO1924-3:2005 Nm/g CD 49.1 elongation at break ISO1924-3:2005 % md 12.7 elongation at break ISO1924-3:2005 % CD 9.0 train breaking work ISO1924-3:2005 J/ ^m2 md 1007 train breaking work ISO1924-3:2005 J/ ^m2 CD 461 Bendtsen roughness ISO8791-2:2013 ml/min top 1970 Bendtsen roughness ISO8791-2:2013 ml/min bottom 2480 bursting strength ISO 2758:2014 kPa 903 wet strength index ISO 3781:2011 Nm/g md 15.8 Tear resistance index ISO1974:2012 mN.g/m ² md 12.7 Tear resistance index ISO1974:2012 mN.g/m ² CD 20.6 Elongation at break ratio ISO1924-3:2005 - MD/CD 1.41 tear length ISO1924-3:2005 km md 12.1

Needless to say, the kraft papers according to the invention can additionally be calendered, for example in a soft nip or long nip calender, or also subjected to a coating treatment, such as a dispersion coating treatment. With such further treatments, however, the essential properties of the packaging material, such as elongation at break, Bendtsen roughness, Tear length, tear propagation resistance index, tensile strength index are not changed. In this regard, it should be noted that the additional treatment steps, such as coating and calendering, must not change the tearing length, the tear propagation resistance index and the like, and in particular must not worsen them. If a loop or banderole is also made from the packaging material, it must be ensured that the packaging material is arranged in such a way that the original machine direction is arranged in such a way that, when the banderole is subjected to a stretching load, it causes an increase in diameter or expansion by up to 20 % of banderole or loop allowed. The manner in which the free ends of the packaging material forming the loop or band are connected can be changed by an optionally applied coating on one or both sides of the band. Without a coating, the free ends can be connected by gluing, stapling, brimming or even sewing or the like. In the case of a packaging material coated on one side, a connection using a hot-melt adhesive, hot-melt or the like can also be provided. In the case of packaging materials coated on both sides, direct connections of two coating layers can be provided, which can be achieved in an extremely short amount of time, but may be disadvantageous for environmental reasons. The same applies to multi-layer packaging materials.

Claims (15)

Packaging material (1) consisting of an unbleached kraft paper with a kappa value according to ISO 302:2015 between 38 and 60, preferably between 40 and 58 as base paper, the kraft paper being made of at least 90% primary cellulose and a basis weight according to ISO 536: 2019 between 65 g/m ² and 170 g/m ² , characterized in that it has an elongation at break ratio MD/CD according to ISO 1924-3:2005 of ≥ 1.1, a breaking length in the machine direction according to ISO 1924-3:2005 of ≥10 km and that it has a tear resistance index in the transverse direction according to ISO 1974:2012 of ≥ 16.0 mN.m ² /g. Packaging material (1) according to Claim 1, characterized in that it contains at least 90% primary cellulose, containing at least 80%, preferably at least 85%, in particular at least 88% cellulose with an average length-weighted fiber length according to ISO 16065-2:2014 between 2.0 mm and 2.9 mm and less than 5%, preferably less than 4.5%, in particular less than 4.2% fillers and cationic starch and other processing aids. Packaging material (1) according to claim 2, characterized in that the primary pulp consists of a mixture consisting of at least 80% softwood pulp, more preferably at least 90% softwood pulp, in particular at least 95% softwood pulp with an average length-weighted fiber length according to ISO 16065-2:2014 of at least 2.0 mm, preferably at least 2.2 mm and the remainder consists of hardwood pulp with a mean length-weighted fiber length according to ISO 16065-2:2014 of at least 1.0 mm. Packaging material (1) according to Claim 1, 2 or 3, characterized in that it has a starch content of 0.5% to 2.2% of the paper, in particular 0.7% to 2.0%. Packaging material (1) according to one of Claims 1 to 4, characterized in that the primary cellulose is contained as ground, in particular high-consistency ground cellulose with a Schopper-Riegler degree of grinding according to ISO 5267-1:1999 between 13°SR and 20°SR. Packaging material (1) according to one of Claims 1 to 5, characterized in that it has a tensile strength index in the machine direction according to ISO 1924:3 - 2005 of ≥ 105 Nm/g, preferably at least 115 Nm/g. Packaging material (1) according to one of Claims 1 to 6, characterized in that it has a longitudinal TEA index according to ISO 1924-3:2005 greater than 5.0 J/g, preferably greater than 5.5 J/g. Packaging material (1) according to one of Claims 1 to 7, characterized in that it has a bursting strength according to ISO 2758:2014 of greater than 750 kPa, preferably greater than 770 kPa, particularly preferably greater than 800 kPa. Packaging material (1) according to one of Claims 1 to 8, characterized in that it has a wet strength index according to ISO 3781:2011 in the machine direction of at least 14.0 Nm/g, in particular 15.2 kN/m, particularly preferably at least 15 5 Nm/g. Banderole (1) produced from a packaging material (1) according to one of Claims 1 to 9, characterized in that it essentially consists of a closed, in particular flanged, glued, preferably double-glued, welded, stapled, sewn or riveted in the transverse direction unbleached kraft paper produced paper web is formed, and that a machine direction of the paper web forms a circumferential direction of the banderole. Banderole (1) according to Claim 10, characterized in that it is subjected to tensile stress by enclosed objects (5), in particular with a tensile stress which is less than an elongation at break in the machine direction (MD) measured according to ISO 1924-3:2005 of the paper web , is charged. Banderole (1) according to Claim 10 or 11, characterized in that the elongation at break in the machine direction (MD), measured according to ISO 1924-3:2005, of the paper web is ≥ 8%. Method for forming a band from a packaging material according to one of Claims 1 to 9, characterized in that a length of the packaging material slightly exceeding the circumference of the band to be formed is cut off from a web of packaging material essentially consisting of unbleached kraft paper unrolled in the machine longitudinal direction, the cut length being cut off length of the packaging material is pivoted by 90°, those two free edges of the cut length, which run in the transverse machine direction when the web of packaging material is unwound, are folded over one another and closed to form a tube, and that a large number of banderoles are severed from the closed tube or for prepared for separation, in particular perforated, scored or marked. Method according to Claim 13, characterized in that the pivoting of the cut length of packaging material by 90° is carried out before or after folding over and sealing those two free edges of the cut length which run in the cross-machine direction when the web of packaging material is unwound. Use of a banderole produced from the packaging material according to one of Claims 1 to 9 for tightly enclosing a plurality of objects which are the same or different from one another.

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