PACKAGING MATERIAL AND BANDEROLE MADE FROM IT

Description

[0001] 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 base material, wherein the kraft paper is made of at least 90% primary pulp and has a basis weight according to ISO 536:2019 between 65 g / m 2< and 170 g / m 2<, as well as to a banderol made from such a packaging material, a method for producing the same and a use of the packaging material.

[0002] Unbleached kraft paper is widely used as a packaging material due to its high resistance to tearing and its good stability when exposed to moisture and chemicals. Regardless of whether it is bleached or unbleached, kraft paper is also easy to print on, meaning that the consumer of the packaged product can see the necessary information printed directly on the packaging. A typical application for kraft paper, and in particular unbleached kraft paper, is in the manufacture of bags for packaging a wide variety of materials, such as building materials, sharp-edged materials, foodstuffs, toys, and the like. In the packaging sector, however, there is not only the form of packaging in which the product to be packaged is completely wrapped in the packaging paper, such as, for example,Not only are bags closed on all sides, but it is often possible to simply surround goods to be packaged or goods to be sold in bundles with a type of bow on which information about the contents, shelf life or similar, and often also brand names, is printed. Such bows are also often used to hold together a number of similar or different goods that belong together and, for example, in the clothing sector, several items, such as a number of T-shirts, socks or similar, are often packaged simply by surrounding them with a bow or banderol. It is important for the packaging material from which such a bow is made that it protects the item to be packaged or sold in bundles.tightly encloses the goods to be enclosed so that the loop cannot be pulled down accidentally, one or more of the products enclosed by the loop cannot fall out and it is further ensured that the goods to be enclosed by the loop can, on the one hand, be inserted into it without damage and, on the other hand, during such insertion or subsequent transport, handling or the like, the loop surrounding the goods does not tear or become damaged in any other way.

[0003] Likewise, it is often necessary to provide tubular packaging materials into which compressible or resilient objects must be packaged in their most compressed form, if possible. This is to minimize the space required for these packages and, at the same time, to ensure that the packaged goods are not compressed and decompressed unnecessarily often during transport, which could potentially lead to material fatigue. In this context, it is particularly important that the tensile stress exerted by the resilient goods packaged within them does not exceed the packaging material's stretchability, causing it to tear, or that the tubular packaging material is not damaged when the goods to be packaged are inserted.To date, plastic films or tapes have been considered the most suitable for this purpose, as they can be produced in a variety of configurations and customized to specific requirements. For environmental reasons, efforts are being made to replace plastic packaging as much as possible with packaging made from renewable resources. Recently, there has been increased research into producing specialty papers, particularly kraft papers, that meet a wide range of requirements regarding durability, stretchability, moisture resistance, and so on, as a replacement for plastic packaging.In particular in cases where ring-shaped, closed tubes or loops have to be used as packaging materials, there is the problem that packaging made of paper, for example, is made from a flat paper web, which web has to be glued or otherwise sealed in some other way to form the ring or tube. If this closure is only closed after the goods to be packaged have been inserted, the time required for the adhesive to harden or dry may be too long for mass production, so that, similar to plastic packaging, it is necessary to form this tube, ring or loop before the products it is to surround are inserted. In order for products to be inserted into such a tube, ring or loop without destroying it, this type of packaging material orPackaging paper must not only exhibit excellent stretchability in the radial direction, i.e., in the circumferential direction of the ring or loop, but must also not tear at the edges, especially when inserting items. WO2021 / 053186 describes a kraft paper suitable for sack paper.

[0004] US 2020 / 290321 describes a kraft paper for packaging.

[0005] WO 2021 / 186282 describes a packaging paper.

[0006] The present invention therefore aims to provide a packaging material made of unbleached kraft paper which does not tear in the machine longitudinal direction or cross-machine direction under high loads, in particular a load that stretches the paper, and which is or remains sufficiently elastic or resilient over time that the objects packaged therein cannot fall out even after a long time due to a loss of tension or elasticity of the packaging material.

[0007] To achieve this object, the packaging material according to the invention is essentially characterized in that it contains at least 90% primary pulp, containing at least 80%, preferably at least 85%, in particular at least 88% pulp 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 as well as cationic starch and other processing aids, that the primary pulp is contained as ground, in particular high-consistency ground pulp with a Schopper-Riegler freeness according to ISO 5267-1:1999 between 13 °RS to 20 °RS, that it has a starch content of 0.5% to 2.2% of the paper, in particular of 0.7% to 2.0%, that it has an elongation at break ratio MD / CD according to ISO 1924-3:2005 of ≥ 1.1,a tear length in the machine direction according to ISO 1924-3:2005 of ≥10 km and a tear resistance index in the transverse direction (CD) according to ISO 1974:2012 of ≥16.0 mN.m 2 / g. The unbleached kraft paper used in the packaging material has an elongation ratio MD / CD according to ISO 1974:2012 of ≥1.1, ensuring that its extensibility in the machine direction (MD) is greater than that in the transverse direction, ensuring that the packaging material is not only extensible in the MD and CD, but can also be subjected to a greater change in length in one direction than in the other without fear of destruction, particularly tearing, of the packaging material.

[0008] Because the packaging material contains at least 90% primary pulp, containing at least 80%, preferably at least 85%, in particular at least 88% pulp 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 as well as cationic starch and other processing aids, it is possible to provide an unbleached kraft paper with an extremely tear-resistant structure and, in particular, due to the narrow length distribution of the fiber lengths of the primary pulp used, to achieve excellent homogeneous paper properties both in the machine direction and in the transverse direction.Due to its durability and its ability to be (micro)creped in a Clupak system, such unbleached kraft paper can also be used safely and reliably for packaging sharp-edged objects or heavy materials, such as cement or beverage bottles. By further containing less than 5%, preferably less than 4.5%, in particular less than 4.2% (the percentages stated in the context of the present invention are always to be understood as weight percent) fillers, as well as cationic starch and processing aids, it is possible to simultaneously obtain a durable but not excessively stiff unbleached kraft paper in which high percentages of starch, particularly cationic starch, can be used due to the lignin and hemicelluloses remaining in the kraft paper and the associated high number of negative charges.Since unbleached kraft paper produced in this way is not excessively stiff but extremely stretchable, it is possible, particularly when bows, banderoles or tubes are made from this packaging material, to securely and reliably enclose the objects packaged therein without having to fear that they will accidentally slip out of the packaging material, whereby when producing such tubes or bows, care must be taken to ensure that the unbleached kraft paper has a greater stretchability in the winding direction of the bow than in the transverse direction of the loop.

[0009] By designing the packaging material such that it has a starch content of 0.5% to 2.2% of the kraft paper, in particular 0.7% to 2.0%, the excellent mechanical properties of the unbleached kraft paper make it possible to maintain the surface smoothness of at least one side of the kraft paper and keep the Bendtsen roughness low, thus providing excellent printability on 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 maximize the adhesion of the packaging material according to the present invention to the inside of tubular or ring-shaped packages, i.e., the side facing away from the "top side," in order to minimize the loss of the items packaged therein due to slipping.

[0010] By designing the packaging material in such a way that the primary pulp is ground, in particular high-consistency ground, with a Schopper-Riegler freeness level of between 13 °SR and 20 °SR according to ISO 5267-1:1999, as is the case with a further development of the invention, it is possible to break up any remaining fiber agglomerates, such as strips and splinters, thereby producing a uniform sheet or particularly homogeneous kraft paper in which an optimized combination of fiber flexibility and tear resistance index in the transverse direction can be achieved. It goes without saying that high- orBy means of low-consistency grinding of paper, both the tear length and the air permeability of the paper can be adjusted, although the latter is not important in the present case, especially in the case of an optional application of coatings, since neither a rapid filling of closed bags made of the packaging material according to the present invention is to be achieved, nor does the air permeability otherwise result in advantageous or negative properties for packaging made from the packaging material.

[0011] By keeping the elongation at break ratio MD / CD ≥ 1.1 according to ISO 1974:2012, it is further ensured that even items that do not have a homogeneous, even or smooth surface can be safely and reliably packaged in this packaging material based on unbleached kraft paper, since the paper, essentially after it has returned 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 hold goods with uneven surfaces safely and reliably.At the same time, the elongation is sufficiently large to allow the products to be inserted into the paper without damaging it, particularly into tubular sleeves formed from this paper. Furthermore, it is ensured that after the materials have been inserted and stretched, the paper returns to its original shape and tightly encloses the packaged objects, so that there is no need to fear that packaged objects will fall out of, for example, tubular or ring-shaped packaging made from the packaging material according to the invention. 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.

[0012] The fact that the tear length in machine direction is ≥ 10 km according to ISO 1924-3:2005 also ensures that the machine strength in the longitudinal direction of the packaging material is so high that even if, for example, tubular or ring-shaped packaging is made from it, even non-flexible objects can be inserted into the packaging material formed in this way without there being any risk of the kraft paper accidentally tearing. Furthermore, the tear resistance index in the transverse direction is ≥ 16.0 mN.m 2 < / g according to ISO 1974:2012, which ensures that there is no risk of a free edge of the packaging material tearing, even if high loads are accidentally applied to the edge of the packaging material, and in particular when tubular or ring-shaped packaging is made from it.Ring-shaped products made from this packaging material, such as bows or banderoles, do not have to fear tearing of the packaging material when inserting the goods to be packaged and thus destruction of the packaging.

[0013] By designing the packaging material so that a tear 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 withstand heavy loads even at its edges without fear of tearing or tearing of the paper from the edge to the center. Finally, this prevents even a small tear from forming in the packaging material from accidentally enlarging.

[0014] In the context of the present invention, the term "packaging material" refers essentially to unbleached kraft paper, which may optionally be coated on one or both sides. Furthermore, it may comprise one or more layers of kraft paper.

[0015] According to a further development, the packaging material can also consist of 100% primary pulp. By making the packaging material, in particular the unbleached kraft paper, of 100% primary pulp, it is possible to even more reliably avoid negative influences on the end product which arise, for example, from recycled pulp as well as from pulp obtained from waste paper. In particular, this makes it possible to avoid the reduced strength or elongation at break of the packaging material which is usually caused by waste paper or recycled pulp. In connection with the present invention, it is important that in particular the elongation at break or the elongation at break ratio, the tear length in the machine direction and the tear resistance index in the transverse direction can be kept high and as constant as possible over time in order to provide consistent material properties which make it possible to produce tubular packaging orTo produce banderoles in which even heavy or sharp-edged objects can be packed and / or wrapped and stored for extended periods without there being any risk of the unbleached kraft paper tearing or tearing or of the packaging produced with it deteriorating.

[0016] According to a further development of the invention, the packaging material is designed such 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 hardwood pulp with an average length-weighted fiber length according to ISO 16065-2:2014 of at least 1.0 mm.Due to the predominant amount of softwood pulp with an average length-weighted fiber length according to ISO 16065-2:2014 of at least 2.0 mm and the rest of hardwood pulp with an average length-weighted fiber length according to ISO 16065-2:2014 of at least 1.0 mm, the strength property of at least one side of the unbleached kraft paper can be positively influenced by the softwood pulp and the smoothness by the hardwood pulp, and a targeted choice of the pulp composition can provide a packaging material with both excellent mechanical properties, in particular elongation at break ratio, and sufficient smoothness, which provides good printability.Furthermore, with such a choice of pulp mixture, in particular the high contents of softwood pulp, it can be ensured that an unbleached packaging material produced in this way has a large tear length in the machine direction, whereby a particularly resilient packaging material can be provided in which even objects with a higher weight can be packaged without the packaging necessarily having to have a bottom and / or top surface.

[0017] As a further development of the invention, the packaging material is designed such 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, ensuring non-destructive packaging of even heavy or sharp-edged objects in the packaging material according to the present invention. The tensile strength index in the machine direction according to the invention further ensures that, when producing, for example, tubular packaging or loop-shaped or banderol-shaped packaging from the packaging material according to the invention, it is possible to provide sufficient resilience of the packaging material, whereby even heavy objects can be reliably fitted into such a loop or banderol made of the packaging material and, moreover, there is no risk of the material tearing.

[0018] Likewise, as is the case with a further development of the invention, the packaging material has a TEA index in the machine direction according to ISO 1924-3:2005 of greater than 5.0 J / g, preferably greater than 5.5 J / g. Because the TEA index in the machine 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 tearing. The TEA index is understood to mean the tensile energy absorption index (TEA) according to ISO 1924-3:2005.

[0019] In order to reliably prevent the packaging material according to the invention from tearing or bursting from the edges to the center, the invention is further developed such that the packaging material has a bursting strength according to ISO 2758:2014 of greater than 750 kPa, preferably greater than 770 kPa, and particularly preferably greater than 800 kPa. According to the invention, the bursting strength is adjusted or increased, among other things, by a combination of the following measures: use of softwood pulp, a low filler content, and a high proportion of, for example, cationic starch. Furthermore, refining, in particular low-consistency refining, also has a positive influence on the bursting strength.

[0020] By designing the packaging material 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, as corresponds to a further development of the invention, it is possible to use the packaging material to provide, in particular, tubular or ring-shaped packaging which is also suitable for use in humid environments. In particular, if, for example, food packaging or loops which surround and hold together a plurality of foodstuffs or foodstuffs are made from the packaging material, contact with condensation, moisture or a humid environment cannot be avoided, so that a high wet strength ora high wet strength index, without having to use permanent wet strength agents or large quantities thereof, in the manufacture of the packaging material consisting essentially of unbleached kraft paper, is desirable.

[0021] Surprisingly, such high wet strength can also be achieved with high dry strength using the packaging material according to the present invention. Typically, achieving high wet strength requires the use of larger amounts of auxiliary materials, such as wet strength agents, which in turn pose problems when recycling the packaging material to be produced, which essentially consists of unbleached kraft paper. Since the dry strength, expressed by the tensile strength index in the machine direction, of the packaging material according to the invention, which essentially consists of unbleached kraft paper, is ≥ 105 Nm / g, sufficient wet strength can be achieved surprisingly in a very resource-efficient manner without, or only by adding, minimal amounts of wet strength agents.

[0022] In this 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. Urea-formaldehyde- or melamine-formaldehyde-based products are also conceivable as wet strength agents, but these are no longer used preferentially to avoid health risks. When the wet strength agents react with cellulose fibers, crosslinks form between the fibers, which lead to increased water resistance of the resulting paper. However, the resulting hydrophobic linkage prevents easy or successful recycling of paper treated with these wet strength agents. Therefore, returning used packaging paper to a pulp cycle is not feasible, or only possible to a limited extent, through the use of high temperatures and / or additional chemicals and additives.It is therefore desirable to keep the amount of wet strength agents used as low as possible, which is surprisingly achievable with a paper or packaging material according to the invention.

[0023] The invention further aims to design or provide a banderol from the packaging material according to the present invention, with which banderol it is possible to package or enclose even a plurality of heavy, unconnected products and to transport them without there being any risk of the packaging material tearing.

[0024] To achieve this object, according to the invention, a band is provided made from the packaging material of the present invention, which is designed such that it is formed from a paper web that is closed, in particular crimped, glued, preferably twice glued, welded, stapled, sewn or riveted, in the transverse direction, essentially made from unbleached kraft paper, and such that a machine direction of the paper web forms a circumferential direction of the band. Due to the fact that the paper web is formed from a paper web that is closed, in particular crimped, glued, preferably twice glued, welded, stapled, sewn or riveted, in the transverse direction, essentially made from unbleached kraft paper, it is possible to compensate for the greater stretch that the unbleached kraft paper has in the machine direction in the circumferential direction of the band.The tubular packaging is designed to be provided so that, thanks to the excellent stretchability of the packaging material in the machine direction, even a plurality of objects does not tear or further tear the packaging material when inserted into the band or into the packaging material glued together to form a ring. Since it is possible to enclose a plurality of objects with the band, it is of course possible to enclose and hold together several objects, whether similar or different, without the need for packaging that completely surrounds 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 stretch 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 can be inserted into a band that has already been glued to form a ring, using the stretch properties of the packaging material, without there being any risk of the band tearing and are held firmly in this ring after they have been inserted due to the resilience of the packaging material.

[0025] By binding the packaging material into a ring, loop, or banderol that encloses a plurality of items in the machine direction of the paper web, it is also possible to insert the majority of items into such a banderol without fear of the banderol tearing in the transverse or longitudinal direction, or at the edges. It goes without saying that such a banderol represents an extremely paper-saving type of packaging, with which items can be packaged and held together safely and reliably.

[0026] By enclosing at least two identical or different objects, the band ensures that any size of container can be formed. Due to the MD / CD elongation at break ratio according to ISO 1924-3:2005 of ≥ 1.1 to approximately 3 and the tear resistance index in the transverse direction according to ISO 1974:2012 of ≥ 16.0 mN.m 2< / g, these containers can be reliably inserted into the band or the tubular product without any risk of the paper edges tearing or being torn out. Even heavy objects or objects that are long or tall compared to the width of the band can be packaged in such a band without any risk of the band 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 there is no risk of the banderol tearing and subsequently being torn even if one or more objects are tipped over.

[0027] The band can be designed such that the plurality of objects are arranged in several rows, circularly, or forming a dense package within the band. With such an arrangement of the enclosed objects, for example, conventional beverage packages comprising two, six, or even twelve bottles can be enclosed by a band according to the invention, or food products such as zucchini or bananas can be arranged in a band, or even several identical foam elements, such as foam cushions or metal or wooden rods, can be arranged inside such a band.

[0028] According to a further development of the invention, the band is designed such that it is subjected to tensile stress by the enclosed objects, in particular to a tensile stress that is less than the elongation at break in the machine direction (MD) of the paper web, measured according to ISO 1924-3:2005. The tensile stress on the objects packaged inside such a band ensures that an object does not accidentally fall out of the band, which could subsequently compromise the stability of the remaining products.

[0029] In order to provide sufficient stretchability of the packaging material and also to be able to provide sufficient recovery, the packaging material is essentially designed so that the elongation at break in the machine direction (MD) of the paper web, measured according to ISO 1924-3:2005, 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 bags and the like, which are subjected to heavy loads in the MD. Surprisingly, it has been shown that bands made from such a material are able to hold packaged products securely and reliably due to the excellent recovery capacity of this material, without there being any risk of the products slipping or falling out of the band, or of the band tearing or ripping when inserting the products.

[0030] A further object of the present invention is to provide a method for forming a band from the packaging material according to the invention. Due to conventional manufacturing processes, the problem essentially lies in the fact that, due to appropriate treatments, a paper web generally exhibits greater stretch properties in the machine direction than in the transverse direction. While isotropic papers are already known that exhibit identical properties in the longitudinal and transverse directions, their production on large paper machines is limited, and in particular, these papers typically exhibit at least slightly poorer properties in the transverse direction.

[0031] In order to be able to make optimal use of the advantageous properties of the packaging material according to the invention in a banderol, the method according to the invention is designed in such a way that a length of packaging material which slightly exceeds a circumference of the banderol to be formed is cut off from a web of packaging material consisting essentially of unbleached kraft paper which is unrolled in the longitudinal direction of the machine, the cut-off length of packaging material is pivoted by 90°, those two free edges of the cut-off length which run in the cross-machine direction when the web of packaging material is unrolled are folded over one another and sealed to form a tube, and that a plurality of banderoles are severed from the sealed tube or prepared for separation, in particular are perforated, scored or marked. Due to the lack of possibility orDue to the economic futility of making cuts or a multitude of cuts in the paper in the longitudinal direction of the machine in an unwinding paper web on a paper machine, the process is essentially carried out in such a way that first a length of the packaging material is cut from an unwinding web of packaging material, which length essentially corresponds to the circumference of a banderol to be produced. In this case, a certain excess length can of course 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 necessary, to form a single banderol. After cutting off the corresponding length, a tube can either be formed directly from the cut length, whereby the paper is then folded together in such a way that in principle the transverse direction, iethe width of the packaging material web forms the circumferential length of the tube, or the cut piece of packaging material can be turned 90° and then glued, crimped, riveted, sewn, or similarly bonded to form a tube. In a final step, it is then necessary to separate pieces corresponding to the width of the band from the resulting tube. The separation can be achieved by cutting, punching, tearing, etc., whereby perforations, marking lines, pre-punched areas, etc. can be created beforehand. Depending on the intended purpose and final use of the band, this can either be done immediately or at the end customer's site.It makes sense not to separate those pieces that have a large number of bands in advance, since printing is generally easier if larger areas can be printed at the same time.

[0032] According to a further development of the method according to the invention, the method can be carried out such that the pivoting of the cut length of packaging material by 90° is carried out before or after the two free edges of the cut length that run in the cross-machine direction during unwinding of the web of packaging material are folded over and sealed. As explained above, it is irrelevant whether the pivoting of the cut length of packaging material by 90° is carried out before or after the two free edges of the cut length are folded over to seal them.

[0033] The packaging material according to the invention can, as corresponds to a further development of the invention, be used as a banderol, whereby it should not go unmentioned that, of course, conventional bags and the like could also be made from this packaging material, although this only seems sensible for high-performance products due to the special material properties.

[0034] The invention is further explained below with reference to exemplary embodiments and drawings. These show: Fig. 1 a schematic representation of possible ways of connecting a packaging material according to the invention to a banderol or loop; and Fig. 2 a schematic representation of the process sequence for producing a banderol from the packaging material according to the invention.

[0035] In detail, Fig. 1a) schematically shows a banderol or loop 1, which banderol 1 is designed such that two free ends 2, 3 of the packaging material forming the banderol 1 overlap and at least one connection is formed in the region of the overlap 4.

[0036] With such a packaging material 1, which is designed in particular as a loop or band, it is thus possible to hold a plurality of identically or differently designed objects by means of the band 1, without, for example, the need for additional plastic packaging that extends over the entire package of objects. The area of ​​the connection 4 can comprise any type of connection, such as, for example, surface adhesives (see Fig. 1b )), point-shaped bonding (see Fig. 1c )), or it can be any type of connection, such as sewing (see Fig. 1d)), brims, large-area gluing, or similar methods can be used. A band of this type is then pulled over the objects to be held together, whereby the objects are held together tightly and firmly due to the resilience of the material.

[0037] 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 forming a plurality of banderoles 1. In the Fig. 1b ) the free ends 2, 3 of the packaging material are again arranged overlapping and the connecting area 4 is glued over its entire surface, as shown by a dashed area. The dashed lines 11 show in Fig. 1b ) possible dividing lines for separating individual banderoles 1.

[0038] In Fig. 1c) is a representation of an endless tube made of the packaging material according to the invention in an analogous manner to that shown in Fig. 1b ) is shown, whereby instead of a full-surface bond in the overlap area, 4 point-shaped bonding points were implemented, arranged in two offset rows. It goes without saying that any other type of bonding, be it two individual bonding lines, one bonding line, or the like, can of course be chosen.

[0039] In Fig. 1d ), which also contains a representation like in Fig. 1b ) of the packaging material according to the invention, it is shown that the free ends 2, 3 of the packaging material forming the endless tube are sewn to a second layer of the packaging material 8, as is schematically indicated by the seam lines 6.

[0040] With such bands 1, it is now possible to package a wide variety of objects together in a captive manner 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 packaged. When such a band 1 is pulled over objects to be packaged, in particular heavy or hard objects, the resilience of the unbleached kraft paper forming it, in particular its elongation at break, tensile strength or tear resistance index, ensures that even if a small tear should form in the packaging material 8 forming the band 1, this tear will not tear further. Moreover, the band 1 thus formed contracts sufficiently after stretching to ensure that the objects packaged therein can also slip out after packaging is completed.In addition, due to the special design of the packaging material 8, a certain degree of static friction can be exerted on the items packaged therein, ensuring that the items are held immovably inside the banderol 1 and that individual or multiple items are reliably prevented from slipping out. The static friction mentioned here can be exerted not only by the banderol 1, but also, for example, by the surface of the items packaged therein.

[0041] In Fig. 2 , in which the reference numerals of Fig. 1 are retained, the process sequence for producing a banderol from the packaging material 8 according to the invention is shown schematically.

[0042] In Fig. 27 designates a roll of packaging material 8, as it is wound onto a reel during production, for example from a paper machine. The packaging material 8 is unwound from the roll 7 of packaging material 8 in the direction of 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 packaging material 8 has been unwound, it is cut off along the width of the packaging material 8, as indicated by dashed line 10. In a second step, this cut-off 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-off piece of packaging material 8, as again indicated by arrow 9.The cut-off 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 band 1 to be formed from this packaging material 8, wherein, depending on the subsequent method of joining the packaging material 8, either a slight excess length is selected in order to be able to stick the ends on top of one another, or in principle the exact circumferential length of the band is selected if the connection is made by crimping, clamping, sewing or the like. In a third step, a tube is formed from this cut-off length of packaging material 8, wherein any conventional tube forming method can be used here, as is indicated in the figure. In the present case, the tube is formed such that the free ends 2, 3 of the packaging material 8 are spaced apart from one another by a distance oroverlap by a length 4, in order to subsequently be able to glue the free ends 2, 3 together, for example, in particular even to glue them twice. The free ends of the packaging material 8 are, as shown in the . Fig. 1 designated by the reference numerals 2 and 3 and the overlapping piece with 4, as shown for example in Fig. 1a is shown. After gluing the packaging material 8, the tube thus produced 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 according to the invention from the material.

[0043] It goes without saying that the second step of the process of folding the packaging material 8 by 90° can also be performed after the tube forming process. In any case, the packaging material 8 must be joined together along the edges 2, 3 in order to ensure that the favorable material properties resulting from the machine direction of production are available in the circumferential direction of a finished banderol 1.

[0044] Regarding the optional process steps, such as printing, perforation, or the like, it should be noted that these can be performed before or after any step following the separation of the web of packaging material 8 from the drum. Thus, it may be advantageous to print directly on the separated piece of packaging material and only then form a tube from the packaging material 8.

[0045] The band or bow 1 can be not only single-colored, but also printed in multiple colors, provided with company name, logos, etc., and can also have a single-sided or double-sided coating, for example, to improve the moisture resistance of the packaging material 8. Finally, it can also have more than one layer of unbleached kraft paper. In this case, it should be noted that the essential properties of the band 1 must not be altered, and neither the breaking elongation nor the bursting strength, the tear length, etc., may be adversely affected.

[0046] Finally, it goes without saying that a banderol 1 according to the invention can be used not only to hold heavy and hard objects or plastic containers together, but also, for example, to surround socks and to bind together foodstuffs such as bananas, zucchini, cucumbers, or the like. Goods packaged in cans, such as foodstuffs, boxes, and the like, can also be bound together.

[0047] Furthermore, the invention is explained in more detail using exemplary embodiments. Example 1: Production of a packaging material based on unbleached kraft paper with a grammage of 82 g / m 2 Process description:

[0048] An unbleached pulp consisting of 100% primary softwood pulp (a blend of spruce and pine) with a kappa number of 51 was first subjected to high-consistency refining at a refining capacity of 230 to 240 kWh / t, with the pulp's freeness after high-consistency refining being 17°SR. This pulp was then subjected to low-consistency refining at a refining capacity of 90 to 100 kWh / t. The following additives were added to the approach flow system of the paper machine. The pH was adjusted to a pH of 6.8 to 7.0 with aluminum sulfate. Cationic starch, with a cationization degree (DS) of 0.03, was added at a rate of 17 kg / t of dry paper. Alkenylsuccinic anhydride was used as a sizing agent at a rate of 0.8 kg / t of dry kraft paper, and 10 kg / t of PAAE was used as a wet strength agent. Furthermore, no fillers were added.The pulp consistency at the headbox was 0.19%. Dewatering took place on a Foudrinier wire section and a press section with three nips, one of which could be a shoe press. The line pressure at the three nips was 60 kN / m, 90 kN / m, or 500 kN / m (in the shoe press). Before the still-moist paper was fed to the Clupak system, it was subjected to contact drying, conventional drying with 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 dried to a final residual moisture content of 7.5%.

[0049] The kraft paper can be used as such for the production of bows or banderoles and the paper properties described in the table below were measured in this kraft paper.

[0050] The kraft paper produced in this way had the following properties: Table 1: Paper properties standard Unit Direction Result Grammage ISO 536:2019 g / m 2 82 Tensile strength ISO 1924-3:2005 kN / m MD 8,9 Tensile strength index ISO 1924-3:2005 Nm / g MD 109 Tensile strength ISO 1924-3:2005 kN / m CD 5,4 Tensile strength index ISO 1924-3:2005 Nm / g CD 66,3 Elongation at break ISO 1924-3:2005 % MD 9,6 Elongation at break ISO 1924-3:2005 % CD 8,6 Tensile fracture work ISO 1924-3:2005 J / m 2 MD 578 Tensile fracture work ISO 1924-3:2005 J / m 2 CD 405 Bendtsen roughness ISO 8791-2:2013 ml / min Top 867 Bendtsen roughness ISO 8791-2:2013 ml / min bottom 1250 Burst strength ISO 2758:2014 kPa 781 Wet strength index ISO 3781:2011 Nm / g MD 15,2 Tear resistance index ISO 1974:2012 mN.g / m 2< MD 14,2 Tear resistance index ISO 1974:2012 mN.g / m 2< CD 16,1 Ratio of elongation at break ISO 1924-3:2005 - MD / CD 1,12 Tear length ISO 1924-3:2005 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:

[0051] 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 refining at a refining capacity of 190 to 210 kWh / t. The pulp's freeness after high-consistency refining was 19 °SR. Subsequently, this pulp was subjected to low-consistency refining at a refining capacity of 70 to 80 kWh / t. The additives were added in the approach flow system of the paper machine. The pH was adjusted to a pH of 6.8 to 7.0 with aluminum sulfate. Cationic starch, with a cationization degree (DS) of 0.03, was added at a rate of 14 kg / t of dry paper, and alkenylsuccinic anhydride was used as a sizing agent at a rate of 0.8 kg / t of dry kraft paper. Glycoxalated PAM was used as a wet strength agent at a rate of 10 kg / t of dry kraft paper.Furthermore, no fillers were added. The pulp consistency at the headbox was 0.23%. Dewatering took place on a Foudrinier wire section and a press section with three nips, one of which could be a shoe press. The line pressure at the three nips was 60 kN / m, 90 kN / m, or 500 kN / m (in the shoe press). 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%.

[0052] The kraft paper can be used as such and the paper properties described in the table below were measured using this paper.

[0053] The kraft paper produced in this way had the following properties: Table 2: Paper properties standard Unit Direction Result Grammage ISO 536:2019 g / m 2 130 Tensile strength ISO 1924-3:2005 kN / m MD 16,2 Tensile strength index ISO 1924-3:2005 Nm / g MD 124,6 Tensile strength ISO 1924-3:2005 kN / m CD 6,3 Tensile strength index ISO 1924-3:2005 Nm / g CD 48,5 Elongation at break ISO 1924-3:2005 % MD 10,3 Elongation at break ISO 1924-3:2005 % CD 8,5 Tensile fracture work ISO 1924-3:2005 J / m 2 MD 871 Tensile fracture work ISO 1924-3:2005 J / m 2 CD 372 Bendtsen roughness ISO 8791-2:2013 ml / min Top 1420 Bendtsen roughness ISO 8791-2:2013 ml / min bottom 1890 Burst strength ISO 2758:2014 kPa 812 Wet strength index ISO 3781:2011 Nm / g MD 16,1 Tear resistance index ISO 1974:2012 mN.g / m 2< MD 12,1 Tear resistance index ISO 1974:2012 mN.g / m 2< CD 19,3 Ratio of elongation at break ISO 1924-3:2005 - MD / CD 1,21 Tear length ISO 1924-3:2005 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:

[0054] 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 refining at a refining capacity of 190 to 210 kWh / t. The pulp's freeness after high-consistency refining was 19 °SR. Subsequently, this pulp was subjected to low-consistency refining at a refining capacity of 70 to 80 kWh / t. The additives were added in the approach flow system of the paper machine. The pH was adjusted to a pH of 6.8 to 7.0 with aluminum sulfate. Cationic starch with a cationization degree (DS) of 0.03 was added at a rate of 14 kg / t of dry paper, and alkenylsuccinic anhydride was used as a sizing agent at a rate of 0.8 kg / t of dry kraft paper. Glycoxalated PAM was used as a wet strength agent at a rate of 10 kg / t of dry kraft paper.Furthermore, no fillers were added. The pulp consistency at the headbox was 0.23%. Dewatering took place on a Foudrinier wire section and a press section with three nips, one of which could be a shoe press. The line pressure at the three nips was 60 kN / m, 90 kN / m, or 500 kN / m (in the shoe press). 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%.

[0055] The kraft paper can be used as such and the paper properties described in the table below were measured using this paper.

[0056] The kraft paper produced in this way had the following properties: Table 3: Paper properties standard Unit Direction Result Grammage ISO 536:2019 g / m 2 130 Tensile strength ISO 1924-3:2005 kN / m MD 16,2 Tensile strength index ISO 1924-3:2005 Nm / g MD 124,6 Tensile strength ISO 1924-3:2005 kN / m CD 6,3 Tensile strength index ISO 1924-3:2005 Nm / g CD 48,5 Elongation at break ISO 1924-3:2005 % MD 10,3 Elongation at break ISO 1924-3:2005 % CD 8,5 Tensile fracture work ISO 1924-3:2005 J / m 2 MD 871 Tensile fracture work ISO 1924-3:2005 J / m 2 CD 372 Bendtsen roughness ISO 8791-2:2013 ml / min Top 1420 Bendtsen roughness ISO 8791-2:2013 ml / min bottom 1890 Burst strength ISO 2758:2014 kPa 812 Wet strength index ISO 3781:2011 Nm / g MD 16,1 Tear resistance index ISO 1974:2012 mN.g / m 2< MD 12,1 Tear resistance index ISO 1974:2012 mN.g / m 2< CD 19,3 Ratio of elongation at break ISO 1924-3:2005 - MD / CD 1,21 Tear length ISO 1924-3:2005 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:

[0057] An unbleached pulp consisting of 100% primary softwood pulp with a kappa number of 46 was first subjected to high-consistency refining at a refining capacity of 210 to 220 kWh / t, whereby the freeness of the pulp after high-consistency refining was 18 °SR. This pulp was then subjected to low-consistency refining at a refining capacity of 70 to 85 kWh / t. The auxiliaries were metered in in the approach flow system of the paper machine. The pH was adjusted to a pH of 6.8 to 7.0 using aluminum sulfate. Cationic starch with a cationization degree DS of 0.05 was added at a rate of 12 kg / t of dry kraft paper, and alkenylsuccinic anhydride was used as a sizing agent at a rate of 0.8 kg / t of dry kraft paper. Furthermore, talc was added as a filler at a rate of 2 kg / t of dry kraft paper. The pulp consistency at the headbox was 0.25%.Dewatering took place on a Foudrinier wire section, similar to a press section with three nips, with line pressures at the three nips of 60 kN / m, 80 kN / m, and 80 kN / m, respectively. The kraft paper was pre-dried, then fed to the Clupak line and subjected to a differential speed of -10.9%, then finally dried to a final residual moisture content of 8%.

[0058] The kraft paper can be used as such and the paper properties described in the table below were measured using this kraft paper.

[0059] The paper produced in this way had the following properties: Table 3: Paper properties standard Unit Direction Result Grammage ISO 536:2019 g / m 2 161 Tensile strength ISO 1924-3:2005 kN / m MD 19,1 Tensile strength index ISO 1924-3:2005 Nm / g MD 118,6 Tensile strength ISO 1924-3:2005 kN / m CD 7,9 Tensile strength index ISO 1924-3:2005 Nm / g CD 49,1 Elongation at break ISO 1924-3:2005 % MD 12,7 Elongation at break ISO 1924-3:2005 % CD 9,0 Tensile fracture work ISO 1924-3:2005 J / m 2 MD 1007 Tensile fracture work ISO 1924-3:2005 J / m 2 CD 461 Bendtsen roughness ISO 8791-2:2013 ml / min Top 1970 Bendtsen roughness ISO 8791-2:2013 ml / min bottom 2480 Burst strength ISO 2758:2014 kPa 903 Wet strength index ISO 3781:2011 Nm / g MD 15,8 Tear resistance index ISO 1974:2012 mN.g / m 2< MD 12,7 Tear resistance index ISO 1974:2012 mN.g / m 2< CD 20,6 Ratio of elongation at break ISO 1924-3:2005 - MD / CD 1,41 Tear length ISO 1924-3:2005 km MD 12,1

[0060] It goes without saying that the kraft papers according to the invention can also be calendered, for example in a soft-nip or long-nip calender, or can also be subjected to a coating treatment, such as a dispersion coating treatment. However, such further treatments must not alter the essential properties of the packaging material, such as elongation at break, Bendtsen roughness, tear length, tear resistance index, and tensile strength index. In this regard, it should be noted that the additional treatment steps, such as coating and calendering, must not change, and in particular, impair, the tear length, tear resistance index, and the like. If a loop or bow is furthermore formed from the packaging material,When manufacturing a band, care must be taken to ensure that the packaging material is arranged in such a way that the original machine direction is aligned so that it allows an increase in diameter or stretching of up to 20% of the band or loop when the band is subjected to stretching. By applying a coating to one or both sides of the band, the way in which the free ends of the packaging material forming the loop or band are connected can be changed. Without a coating, the free ends can be connected by gluing, clamping, crimping, sewing, or similar. In the case of a packaging material coated on one side, a connection using hot-melt adhesive, hot-melt adhesive, or similar can also be provided.For packaging materials coated on both sides, direct bonding of two coating layers can be provided. This can be achieved with extremely little time, but may be disadvantageous for environmental reasons. The same applies to multi-layer packaging materials.

Claims

1. Packaging material (1) consisting of an unbleached kraft paper with a Kappa number according to ISO 302:2015 between 38 and 60, preferably between 40 and 58 as base paper, wherein the kraft paper is manufactured from at least 90 % primary cellulose and has a grammage according to ISO 536:2019 between 65 g / m2 and 170 g / m2, 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 a length-weighted mean fibre 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 as well as cationic starch and other process aids, that the primary cellulose is contained in the form of beaten cellulose, in particular, high-consistency refined cellulose having a Schopper-Riegler degree of refining according to ISO 5267-1:1999 between 13 °SR and 20 °SR, that it has a starch content of 0.5 % to 2.2 % of the paper, in particular 0.7 % to 2.0 %, that it has a strain at break ratio MD / CD according to ISO 1924-3:2005 of ≥ 1.1, a tear length in the machine direction according to ISO 1924-3:2005 of ≥10 km, and a tear index in the cross direction according to ISO 1974:2012 of ≥16.0 mN.m2 / g.

2. Packaging material (1) according to Claim 1, characterized in that the primary cellulose consists of a mixture consisting of at least 80 % softwood cellulose, preferably at least 90 % softwood cellulose, in particular at least 95 % softwood cellulose with a length-weighted mean fibre length according to ISO 16065-2:2014 of at least 2.0 mm, preferably at least 2.2 mm and the remainder of hardwood cellulose with a length-weighted mean fibre length according to ISO 16065-2:2014 of at least 1.0 mm.

3. Packaging material (1) according to Claim 1 or 2, 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.

4. Packaging material (1) according to one of Claims 1, 2 or 3, characterized in that it has a TEA index in the longitudinal direction according to ISO 1924-3:2005 greater than 5.0 J / g, preferably greater than 5.5 J / g.

5. Packaging material (1) according to one of Claims 1 to 4, 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.

6. Packaging material (1) according to one of Claims 1 to 5, 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 Nm / g, particularly preferably at least 15.5 Nm / g.

7. Sleeve (1) made from a packaging material (1) according to any one of Claims 1 to 6, characterized in that it is made of a closed, in particular crimped, glued, preferably double-glued, welded, stapled, sewn or riveted in the cross direction, substantially unbleached kraft paper, and that a machine direction of the paper web forms a circumferential direction of the sleeve.

8. Sleeve (1) according to Claim 7, characterized in that it is subjected to tension by enclosed objects (5), in particular with a tensile stress which is smaller than an elongation at break in the machine direction (MD) measured in accordance with ISO 1924-3:2005 of the paper web.

9. Sleeve (1) according to Claim 7 or 8, 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 %.

10. Method for forming a sleeve from a packaging material according to one of Claims 1 to 6, characterized in that a length of the packaging material slightly exceeding the circumference of the sleeve to be formed is cut off from a web of the packaging material substantially consisting of unbleached kraft paper that is unrolled in the machine longitudinal direction is, the cut length of the packaging material is pivoted by 90°, those two free edges of the cut length, which run in the cross-machine direction when the web of packaging material is unrolled, are folded over one another and closed to form a tube and that a plurality of sleeves are separated from the closed tube or prepared for separation, in particular perforated, scored or marked.

11. Method according to Claim 10, characterized in that pivoting the cut length of the packaging material by 90° is carried out before or after folding over and closing those two free edges of the cut length which run in the cross-machine direction when the web of packaging material is unrolled.

12. Use of a sleeve produced from the packaging material according to one of Claims 1 to 6 for tightly enclosing a plurality of objects that are the same or different from one another.