PACKAGING MATERIAL MADE OF UNBLEACHED KRAFT PAPER, SLEEVE PRODUCED THEREFROM, AND METHOD FOR MANUFACTURING SAME

Abstract

A packaging material consisting of an unbleached kraft paper as a base paper, the kraft paper has at least 90% primary cellulose and a grammage of between 65 g/m.sup.2 and 170 g/m.sup.2; the primary cellulose, containing at least 80% cellulose with a length-weighted mean fiber length of between 2.0 mm and 2.9 mm, and less than 5% fillers, the primary cellulose is cellulose beaten with high consistency, the packaging material has a strain ratio break of >1.1, a tear length in the machine direction of >10 km, and a tear index in the cross direction of >16.0 mN.Math.m.sup.2/g. The invention also relates to a method for manufacturing the packaging material, to a sleeve produced from the packaging material, and to a use of the packaging material.

Claims

1. A packaging material consisting of an unbleached kraft paper with a Kappa number according to ISO 302:2015 between 38 and 60, 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/m.sup.2 and 170 g/m.sup.2, wherein the kraft paper contains at least 90% primary cellulose, containing at least 80% of 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%, fillers as well as cationic starch, that the primary cellulose is contained in the form of high-consistency beaten cellulose having a Schopper-Riegler degree of beating according to ISO 5267-1:1999 between 13 SR and 20 SR, that the packaging material has a strain ratio MD/CD of the kraft paper at break 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, a tear index in the cross direction of the kraft paper according to ISO 1974:2012 is >16.0 mN.Math.m.sup.2/g and that the kraft paper is coated on at least one side with a coating material.

2. The packaging material according to claim 1, wherein the primary cellulose consists of a mixture consisting of at least 80% softwood cellulose, with a length-weighted mean fibre length according to ISO 16065-2:2014 of at least 2.0 mm, and the substantial remainder of softwood cellulose with a length-weighted mean fibre length according to ISO 16065-2:2014 of at least 1.0 mm.

3. The packaging material according to claim 2, wherein the packaging material it has a starch content of 0.5% to 2.2% of the paper.

4. The packaging material according to claim 1, wherein the packaging material has a tensile strength index in the machine direction according to ISO 1924:3-2005 of >105 Nm/g.

5. The packaging material according to claim 1, wherein the packaging material has a TEA index in the longitudinal direction according to ISO 1924-3:2005 greater than 5.0 J/g.

6. The packaging material according to claim 1, wherein the packaging material has a bursting strength according to ISO 2758:2014 of greater than 750 kPa.

7. The packaging material according to claim 1, wherein the packaging material has a wet strength index according to ISO 3781:2011 in the machine direction of the kraft paper of at least 14.0 Nm/g.

8. The packaging material according to claim 1, wherein on at least one side a coating material selected from a polyolefin or polylactic acid (PLA) in an amount corresponding to 1/15 to of the grammage of the kraft paper, is applied.

9. The packaging material according to claim 8, wherein the polyolefin is selected from high-density polyethylene (HDPE), low-density polyethylene (LDPE), or polypropylene (PP).

10. The packaging material according to claim 1, wherein the packaging material forms a laminate consisting of several layers of kraft paper and several layers of coating material.

11. (canceled)

12. The packaging material according to claim 10, wherein the laminate has at most 5 layers of the kraft paper, and at most 6 layers of the coating material.

13. The packaging material according to claim 12, wherein each layer of the coating material located between two layers of kraft paper has an amount corresponding to 1/15 to 1/9 of the grammage of the kraft paper and a layer forming an outer side of the laminate of the coating material has an amount that corresponds to 1/11 to of the grammage of the kraft paper.

14. A sleeve made from a packaging material according to claim 1, wherein the packaging material is formed from a coated, at least single-layer web of the packaging material, that is closed, in the cross direction, substantially made of unbleached kraft paper, and that a machine direction of the paper web of the packaging material forms a circumferential direction of the sleeve.

15. The sleeve according to claim 14, wherein the sleeve is subjected to tension by enclosed objects 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 coated paper web.

16. The sleeve according to claim 15, wherein the elongation at break in the machine direction (MD) measured according to ISO 1924-3:2005 of the packaging material is >8%.

17. The sleeve according to claim 14, wherein the sleeve is formed from a laminate consisting of several layers of kraft paper and several layers of coating material, such as at most 5 layers of kraft paper, and at most 6 layers of the coating material.

18. Method A method for forming the sleeve from a packaging material according to claim 14, wherein 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, the cut length of the packaging material is pivoted by 90, 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.

19. The method according to claim 18, wherein pivoting the cut length of the packaging material by 90 is performed before or after folding over and closing the two free edges of the cut length which run in the cross-machine direction when the web of packaging material is unrolled.

20. Use of the sleeve produced from the packaging material according to claim 14 for tightly enclosing a plurality of objects that are the same or different from one another.

Description

DESCRIPTION OF THE DRAWINGS

[0042] The invention is further explained hereinafter using exemplary embodiments and drawings. In the figures:

[0043] FIG. 1 consists of FIGS. 1A, 1B, 1C, and 1D and shows a schematic diagram of possible types of connection of a packaging material according to the invention to form a sleeve or loop; and

[0044] FIG. 2 shows a schematic diagram of the process sequence for producing a sleeve from the packaging material according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0045] In detail, FIG. 1A shows schematically a sleeve or loop 1 shows which sleeve 1 is configured such that two free ends 2, 3 of the packaging material forming the sleeve 1 overlap and at least one connection is formed in the area of the overlap 4.

[0046] With such a packaging material, which is in particular configured as a loop or sleeve, it is therefore possible to hold a plurality of objects of the same or different design by the sleeve 1, without having to use, for example, an additional plastic packaging that extends over the entire package of objects. The area of the connection 4 can have any type of connection, such as for example, flat adhesive bonding (see FIG. 1B, punctuate adhesive bonding (see FIG. 1C), or any type of connection, such as sewing (see FIG. 1D), crimping, large-area gluing or thermal sealing or the like can be used. A sleeve thus formed is then pulled over the objects to be held together, whereby they are held together tightly or firmly due to the resilience of the material.

[0047] FIG. 1B shows a perspective longitudinal view of an endless tube formed from the packaging material according to the invention, which endless tube is intended for forming a plurality of sleeves 1. In the embodiment shown in FIG. 1B, the free ends 2, 3 of the packaging material are again arranged in an overlapping manner and the connection area 4 is adhesively bonded over the entire surface, as shown by a dashed area. The dashed lines 11 in FIG. 1B) indicate possible dividing lines for separating individual sleeves 1.

[0048] FIG. 1C shows a representation of an endless tube made of the packaging material according to the invention in a similar manner to that in FIG. 1B, wherein instead of a large-area adhesive bonding, in the overlap area 4, punctuate adhesive points are implemented which are in particular arranged in two rows which are offset from one another. Needless to say, any other type of adhesive bonding can naturally be selected, whether it is in two individual adhesive lines, one adhesive line or the like. If a packaging material that is coated on one or two sides is used, the adhesive bonding can preferably be achieved by thermal sealing or welding of the coating made of a thermoplastic material.

[0049] In FIG. 1D, in which a diagram as in FIG. 1B of the packaging material according to the invention was also selected, 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 indicated schematically by the seam lines 6.

[0050] With such sleeves 1, it is now possible to captively pack a wide variety of objects together and, in particular, to ensure that, even when heavy objects, such as metal rods or the like, are packed, any tearing of the packaging material 8 is avoided. If such a sleeve 1 is pulled over objects to be packaged, in particular heavy or hard objects, it is possible to ensure that as a result of the resilience of the unbleached kraft paper forming it, in particular due to the elongation at break, tensile strength or even the tear resistance index, if a small tear should be formed in the packaging material 8 forming the sleeve 1, this does not tear any further and, moreover, the sleeve 1 thus formed contracts to such an extent after stretching that any slipping out of the objects packaged therein after the packaging has been completed can be prevented. In addition, due to the special configuration of the packaging material 8, a certain static friction can also be exerted on the objects packaged therein, which ensures that the objects are immovably accommodated inside the sleeve 1 and that any slipping out of one or more of the objects is safely prevented. The static friction mentioned here can be exerted not only by the sleeve 1, but also, for example, by the surface of the objects packaged therein.

[0051] In FIG. 2, in which the reference numerals from FIG. 1 are retained, the process sequence for producing a sleeve from the packaging material 8 according to the invention is shown schematically.

[0052] In FIG. 2, 7 denotes a roll of the packaging material 8, as it is rolled up from production from a paper machine onto a reel. From the roll 7 of the packaging material 8, the packaging material 8 is unrolled in the direction of the arrow 9, which arrow 9 at the same time 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 unrolled, this is cut along the width of the packaging material 8, as indicated by the dashed line 10. In a second step, this cut length of the 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 cross direction of the cut piece of the packaging material 8, as again indicated by arrow 9. The cut piece of packaging material 8 here has a length L in the machine direction of the roll of packaging material 8, which substantially corresponds to the circumference of a sleeve 1 to be formed from this packaging material 8, wherein depending on the subsequent method of connecting the packaging material 8 either a small excess length is selected in order to be able to glue the ends on top of each other, in particular when using a packaging material coated with a thermoplastic material, such as PE or PLA, to be able to seal them thermally, or in principle exactly the circumferential length of the sleeve is selected if the connection is made by crimping, stapling, sewing or the like. In a third step, a tube is formed from this separated length of packaging material 8, wherein any conventional tube forming process can be used here, as indicated in the figure. In the present case, the tube is formed such that the free ends 2, 3 of the packaging material 8 overlap each other by a distance or a length 4 in order to subsequently be able to glue the free ends 2, 3 together, for example, in particular even to be able to glue them twice. The free ends of the packaging material 8 are here, as in FIG. 1, designated by the reference numerals 2 and 3 and the overlapping piece by 4, as shown for example in FIG. 1a. 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 sleeves 1 according to the invention from the material.

[0053] It is unnecessary to note that the second step of the process of turning the packaging material 8 by 90 can also take place after forming the tube. In any case, the packaging material 8 must be connected to one another along the edges 2, 3 in order to have the favourable material properties, which result from the machine direction of the production of the kraft paper, available in the circumferential direction of a finished sleeve 1.

[0054] With regard to the optional process steps, such as printing, perforating or the like, it should be noted that these can be carried out before or after each step following separation of the web of packaging material 8 from the reel. Thus, it can be favourable to print immediately on the separated piece of packaging material and only then form a tube from the packaging material 8.

[0055] The sleeve or loop 1 can not only be designed in one colour, but can also be printed in multiple colours, provided with company names, logos and the like, and it can also have a one-sided or two-sided coating in order, 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. A laminate can thus be formed consisting of more than one layer of the kraft paper, with respectively one layer of the coating material between the individual kraft paper layers and an outer layer of the coating material in each case. The grammages of the individual coating material layers and also the grammages of the individual kraft paper layers can also differ from one another. In this case, it should be noted that the essential properties of the sleeve 1 must not be changed and neither the elongation at break, the bursting strength, the tear length, etc. are changed compared to an optionally coated single-layer paper sleeve.

[0056] Finally, it is unnecessary to point out that with a sleeve 1 according to the invention not only heavy and hard objects or plastic containers can be held together, but also, for example, socks can be surrounded, foods such as bananas, courgettes, cucumbers or the like can be connected to one another or boxes can be closed. Also, for example, goods packaged in cans or food, boxes and the like can be connected to each other to form containers.

[0057] Furthermore, the invention is explained in more detail hereinafter by reference to exemplary embodiments.

Example 1: Production of a Packaging Material Based on Unbleached Kraft Paper with a Grammage of 82 g/m.SUP.2

Process Description

[0058] An unbleached cellulose consisting of 100% primary cellulose from softwood (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, wherein a degree of beating of the cellulose after high-consistency beating was 17 SR. This cellulose was then subjected to low-consistency beating with a beating capacity of 90 to 100 kWh/t. The following auxiliary materials were added to the constant part of the paper machine. Here the pH was adjusted to a pH of 6.8 to 7.0 with aluminium sulphate, cationic starch having a degree of cationization DS of 0.03 was added absolutely dry in an amount of 17 kg/t paper, alkenyl succinic anhydride in an amount of 0.8 kg/t dry kraft paper was added as sizing agent and 10 kg/t PAAE was used as wet strength agent. Furthermore, no fillers were added. The consistency of the cellulose at the headbox was 0.19%. The dewatering was carried out on a Foudrinier wire section and with a press section with three nips, wherein one of the presses can be a shoe press, wherein the line pressure at the three nips was 60 kN/m, 90 kN/m and 500 kN/m respectively (in the shoe press). Before the still wet paper was fed to the Clupak system, it was subjected to contact drying, conventional drying using hot air at 167 C., then pre-dried in a slalom drying 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%.

[0059] The kraft paper can be used as such for the production of bands, loops or sleeves and the paper properties described in the following table were measured in this kraft paper.

[0060] The kraft paper thus produced would have the following properties:

TABLE-US-00001 TABLE 1 Paper property Standard Unit Direction Result Grammage ISO 536:2019 g/m.sup.2 82 Tensile ISO 1924-3:2005 kN/m MD 8.9 strength Tensile ISO 1924-3:2005 Nm/g MD 109 strength index Tensile ISO 1924-3:2005 kN/m CD 5.4 strength Tensile ISO 1924-3:2005 Nm/g CD 66.3 strength index Elongation ISO 1924-3:2005 % MD 9.6 at break Elongation ISO 1924-3:2005 % CD 8.6 at break Tensile ISO 1924-3:2005 J/m.sup.2 MD 578 energy absorption Tensile ISO 1924-3:2005 J/m.sup.2 CD 405 energy absorption Bendtsen ISO 8791-2:2013 ml/min Upper 867 roughness side Bendtsen ISO 8791-2:2013 ml/min Lower 1250 roughness side Bursting ISO 2758:2014 kPa 781 strength Wet ISO 3781:2011 Nm/g MD 15.2 strength index Tear index ISO 1974:2012 mN .Math. g/m.sup.2 MD 14.2 Tear index ISO 1974:2012 mN .Math. g/m.sup.2 CD 16.1 Strain ISO 1924-3:2005 MD/CD 1.12 ratio Tear ISO 1924-3:2005 Km MD 11.06 length

Example 2: Production of a Packaging Material Based on Unbleached Kraft Paper with a Grammage of 130 g/m.SUP.2

Process Description

[0061] An unbleached cellulose consisting of 95% primary cellulose from softwood with a Kappa number of 41 and 5% primary cellulose from hardwood with a Kappa number of 40 was first subjected to high consistency beating with a beating capacity of 190 to 210 kWh/t, wherein the degree of beating of the cellulose after high-consistency beating was 19 SR and this cellulose was then subjected to low-consistency beating with a beating capacity of 70 to 80 kWh/t. The auxiliary materials were added into the constant part of the paper machine. The pH was adjusted to a pH of 6.8 to 7.0 with aluminium sulphate, cationic starch having a degree of cationization DS of 0.03 was added absolutely dry in an amount of 14 kg/t of paper and alkenyl succinic anhydrides were used as the sizing agent in an amount of 0.8 kg/t kraft paper absolutely dry. Glyoxalated PAM with 10 kg/t absolutely dry kraft paper was used as the wet strength agent. Furthermore, no fillers were added. The consistency of the cellulose at the headbox was 0.23%. The dewatering was carried out on a Foudrinier wire section and with a press section with three nips, wherein one of these can be a shoe press, wherein the line pressure at the three nips is 60 kN/m, 90 kN/m and 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 an ultimate final moisture content of 7.5%

[0062] The kraft paper can be used as such and the paper properties described in the following table were measured with this paper.

[0063] The kraft paper thus produced had the following properties:

TABLE-US-00002 Paper property Standard Unit Direction Result Grammage ISO 536:2019 g/m.sup.2 130 Tensile ISO 1924-3:2005 kN/m MD 16.2 strength Tensile ISO 1924-3:2005 Nm/g MD 124.6 strength index Tensile ISO 1924-3:2005 kN/m CD 6.3 strength Tensile ISO 1924-3:2005 Nm/g CD 48.5 strength index Elongation ISO 1924-3:2005 % MD 10.3 at break Elongation ISO 1924-3:2005 % CD 8.5 at break Tensile ISO 1924-3:2005 J/m.sup.2 MD 871 energy absorption Tensile ISO 1924-3:2005 J/m.sup.2 CD 372 energy absorption Bendtsen ISO 8791-2:2013 ml/min Upper 1420 roughness side Bendtsen ISO 8791-2:2013 ml/min Lower 1890 roughness side Bursting ISO 2758:2014 kPa 812 strength Wet ISO 3781:2011 Nm/g MD 16.1 strength index Tear index ISO 1974:2012 mN .Math. g/m.sup.2 MD 12.1 Tear index ISO 1974:2012 mN .Math. g/m.sup.2 CD 19.3 Strain ISO 1924-3:2005 MD/CD 1.21 ratio Tear ISO 1924-3:2005 km MD 12.7 length

Example 3: Production of a Packaging Material Based on Unbleached Kraft Paper with a Grammage of 130 g/m.SUP.2

Process Description

[0064] An unbleached cellulose consisting of 95% primary cellulose from softwood with a Kappa number of 41 and 5% primary cellulose from hardwood with a Kappa number of 40 was firstly subjected to high-consistency beating with a beating capacity of 190 to 210 kWh/t, wherein a degree of beating of the cellulose after high-consistency beating was 19 SR and then this cellulose was subjected to low-consistency beating with a beating capacity of 70 to 80 kWh/t. The auxiliary materials were added into the constant part of the paper machine. The pH was adjusted to a pH of 6.8 to 7.0 with aluminium sulphate, cationic starch with a degree of cationization DS of 0.03 was added absolutely dry in an amount of 14 kg/t of paper and alkenyl succinic anhydrides were used as the sizing agent in an amount of 0.8 kg/t kraft paper absolutely dry. Glyoxalated PAM with 10 kg/t absolutely dry kraft paper was used as the wet strength agent. Furthermore, no fillers were added. The consistency of the cellulose at the headbox was 0.23%. The dewatering was carried out on a Foudrinier wire section and with a press section having three nips, wherein one of which can be a shoe press, wherein the line pressure at the three nips was 60 KN/m, 90 kN/m and 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 an ultimate final moisture content of 7.5%.

[0065] The kraft paper can be used as such and the paper properties described in the following table were measured with this paper.

[0066] The kraft paper thus produced had the following properties:

TABLE-US-00003 Paper property Standard Unit Direction Result Grammage ISO 536:2019 g/m.sup.2 130 Tensile ISO 1924-3:2005 kN/m MD 16.2 strength Tensile ISO 1924-3:2005 Nm/g MD 124.6 strength index Tensile ISO 1924-3:2005 kN/m CD 6.3 strength Tensile ISO 1924-3:2005 Nm/g CD 48.5 strength index Elongation ISO 1924-3:2005 % MD 10.3 at break Elongation ISO 1924-3:2005 % CD 8.5 at break Tensile ISO 1924-3:2005 J/m.sup.2 MD 871 energy absorption Tensile ISO 1924-3:2005 J/m.sup.2 CD 372 energy absorption Bendtsen ISO 8791-2:2013 ml/min Upper 1420 roughness side Bendtsen ISO 8791-2:2013 ml/min Lower 1890 roughness side Bursting ISO 2758:2014 kPa 812 strength Wet ISO 3781:2011 Nm/g MD 16.1 strength index Tear index ISO 1974:2012 mN .Math. g/m.sup.2 MD 12.1 Tear index ISO 1974:2012 mN .Math. g/m.sup.2 CD 19.3 Strain ISO 1924-3:2005 MD/CD 1.21 ratio Tear ISO 1924-3:2005 Km MD 12.7 length

Example 4: Production of a Packaging Material Based on Unbleached Kraft Paper with a Grammage of 161 g/m

Process Description

[0067] An unbleached cellulose consisting of 100% primary cellulose from softwood with a Kappa number of 46 was first subjected to high-consistency beating with a beating capacity of 210 to 220 kWh/t, wherein a degree of beating of the cellulose after high-consistency beating was 18 SR and this cellulose was then subjected to low-consistency beating with a beating capacity of 70 to 85 kWh/t. The auxiliary materials were added into the constant part of the paper machine. The pH was adjusted to a pH of 6.8 to 7.0 with aluminium sulphate, cationic starch with a degree of cationization DS of 0.05 was added in an amount of 12 kg/t of kraft paper absolutely dry and alkenyl succinic anhydrides were used as sizing agent in an amount of 0.8 kg/t of kraft paper absolutely dry. Furthermore, talc was added as a filler in an amount of 2 kg/t of kraft paper absolutely dry. The consistency of the cellulose at the headbox was 0.25%. The dewatering was carried out on a Foudrinier wire section, such as a press section with three nips, wherein the line pressure at the three nips was 60 kN/m, 80 kN/m and 80 kN/m, respectively. The kraft paper was pre-dried, then fed to the Clupak system and subjected to a differential speed of 10.9%, then finally dried to a final residual moisture content of 8%.

[0068] The kraft paper can be used as such and the paper properties described in the following table were measured with this kraft paper.

[0069] The paper thus produced had the following properties:

TABLE-US-00004 TABLE 3 Paper property Standard Unit Direction Result Grammage ISO 536:2019 g/m.sup.2 161 Tensile ISO 1924-3:2005 kN/m MD 19.1 strength Tensile ISO 1924-3:2005 Nm/g MD 118.6 strength index Tensile ISO 1924-3:2005 kN/m CD 7.9 strength Tensile ISO 1924-3:2005 Nm/g CD 49.1 strength index Elongation ISO 1924-3:2005 % MD 12.7 at break Elongation ISO 1924-3:2005 CD 9.0 at break Tensile ISO 1924-3:2005 J/m.sup.2 MD 1007 energy absorption Tensile ISO 1924-3:2005 J/m.sup.2 CD 461 energy absorption Bendtsen ISO 8791-2:2013 ml/min Upper 1970 roughness side Bendtsen ISO 8791-2:2013 ml/min Lower 2480 roughness side Bursting ISO 2758:2014 kPa 903 strength Wet ISO 3781:2011 Nm/g MD 15.8 strength index Tear index ISO 1974:2012 mN .Math. g/m.sup.2 MD 12.7 Tear index ISO 1974:2012 mN .Math. g/m.sup.2 CD 20.6 Strain ISO 1924-3:2005 MD/CD 1.41 ratio Tear ISO 1924-3:2005 Km MD 12.1 length

[0070] It is needless to say that the kraft papers according to the invention can additionally be calendered, for example in a soft nip or long nip calender, or in particular can also be subjected to a coating treatment, such as a dispersion coating treatment with a thermoplastic material, such as HDPE, LDPE, PLA or PP. With such further treatments, however, the essential properties of the packaging material, such as elongation at break, Bendtsen roughness, tear length, tear index, tensile strength index, are not changed, in particular do not deteriorate. If there is a loop or sleeve further manufactured from the packaging material, care must be taken to ensure that the packaging material is arranged such that the original machine direction is arranged such that an increase in diameter or stretching of up to 20% of the sleeve or loop is possible in the event of a stretching stressing of the sleeve. By means of a coating optionally applied on one or both sides of the sleeve, the way in which the free ends of the packaging material forming the loop or sleeve are connected, can be changed. In particular, in such a case, a thermal sealing of the free ends is carried out. Without a coating, the free ends can be connected by gluing, clipping, crimping or even sewing or the like. In the case of a packaging material that is coated on one side, a connection using hot glue, hot melts or the like can also be provided. In the case of packaging materials coated on both sides, a direct connection of two coating layers is in particular provided, which can be achieved with an extremely small expenditure of time.

[0071] Multi-layer packaging materials are preferably formed as laminates consisting of at least one kraft paper layer, preferably several kraft paper layers and at least two coating layers consisting of a polyolefin, in particular HDPE, LDPE or PP or PLA.

[0072] Example 5 shows a laminate consisting of an unbleached kraft paper layer (KP) with a grammage of 120 g/m.sup.2 and an outer coating layer made of HDPE with a grammage of 15 g/m.sup.2 on both surfaces of the base paper. The kraft paper was produced as described in Example 3. An extrusion coating process was used as the coating process. The laminate formed therefore has the following structure: 15 g/m.sup.2 HDPE/120 g/m.sup.2 KP/12 g/m.sup.2 HDPE.

[0073] The laminate thus produced had the properties described in the following table.

TABLE-US-00005 TABLE 4 Paper property Standard Unit Direction Result Grammage ISO 536:2019 g/m.sup.2 150 Tensile ISO 1924-3:2005 kN/m MD 12.5 strength Tensile ISO 1924-3:2005 kN/m CD 5 strength Elongation ISO 1924-3:2005 % MD 12.5 at break Elongation ISO 1924-3:2005 % CD 9.4 at break Tear index ISO 1974:2012 mN .Math. g/m.sup.2 MD 1300 Tear index ISO 1974:2012 mN .Math. g/m.sup.2 CD 2000 WVTR ASTM1249 g/m.sup.2/24 h MD 3 (23 C./ 50% RH) * *WVTR test climate 38 C./100% RH

[0074] Example 6 shows a laminate consisting of 3 kraft paper layers (KP), each having a grammage of 120 g/m.sup.2 and both an outer coating layer made of LDPE with a grammage of 15 g/m.sup.2 and an LDPE coating between two kraft paper layers with a grammage of 12 g/m.sup.2. The kraft paper was produced as described in Example 3. An extrusion coating process was used as the coating process. The laminate formed therefore has the following structure: [0075] 15 g/m.sup.2 LDPE/120 g/m.sup.2 KP/12 g/m.sup.2 LDPE/120 g/m.sup.2 KP/12 g/m.sup.2 LDPE/120 g/m.sup.2 KP/15 g/m.sup.2 LDPE

[0076] The laminate thus produced had the properties described in the following table.

TABLE-US-00006 TABLE 5 Paper property Standard Unit Direction Result Grammage ISO 536:2019 g/m.sup.2 414 Thickness ISOP m ~430 534:2012-02 Tensile ISO 1924- kN/m MD 39.4 strength 3:2005 Tensile ISO 1924- kN/m CD 15 strength 3:2005 Elongation at ISO 1924- % MD 12.9 break 3:2005 Elongation at ISO 1924- % CD 9.4 break 3:2005 Burststrenght ISO 9895:2008 kPa 2442 Tear index ISO 1974:2012 mN .Math. g/m.sup.2 MD 4680 Tear index ISO 1974:2012 mN .Math. g/m.sup.2 CL 7200 WVTR (23 C./ ASTM1249 g/m.sup.2/24 h MD 3 50% RH) * *WVTR test climate 38 C./100% RH

[0077] Furthermore, it is possible to replace one or all of the polyolefin or polylactic acid layers arranged between two layers of paper with a glue and thereby create a firm cohesion of the individual layers forming the laminate. In this case, however, it is essential that the two outer coating layers are made of a polyolefin or PLA.

[0078] A band produced from such a laminate could, on the one hand, be used on conventional strapping machines and, above all, heavy and bulky objects can be held together or packaged therewith without fear of the band tearing. A band produced from such a laminate could therefore be used as a replacement for a conventional strapping band manufactured entirely of plastic.