APPARATUS AND METHOD FOR TREATMENT OF WRAPPING MATERIAL

Abstract

The apparatus (10) for processing a continuous band of wrapping material (40) comprises a roller pair (20, 30) defining a roller gap (12) there between, wherein the rollers (20, 30) have matching convex and concave shapes, respectively. The invention is also directed to a corresponding method for treatment of wrapping material (40).

Claims

1-15. (canceled)

16. An apparatus for processing a continuous band of wrapping material, comprising: a roller pair defining a roller gap there between, wherein the roller pair comprises a male and a female roller, wherein the rollers have matching convex and concave shapes, respectively, wherein both rollers have flat central roller areas, and wherein the female roller has convexly rounded edges, and the male roller has corresponding concavely rounded edges, such that the rollers are adapted to provide a continuous weakened region of the continuous band of wrapping material by displacing the region of the continuous band of wrapping material which is passing between the concavo-convex portion of the roller gap relative to the region of the continuous band of wrapping material which is passing between the flat central portion of the roller gap.

17. The apparatus according to claim 16, wherein the rollers are adapted to provide a continuous weakened lateral edge portion of the continuous band of wrapping material.

18. The apparatus according to claim 16, wherein the rollers have a diameter of between 10 and 50 millimeters, preferably of about 30 millimeters.

19. The apparatus according to claim 16, wherein the width of the rollers is between 15 and 40 millimeters, preferably between 20 and 30 millimeters, and more preferably of about 26 millimeters.

20. The apparatus according to claim 16, wherein the rounded edges of the rollers have a radius of curvature of between 1 and 5 millimeters and preferably of about 3 millimeters.

21. The apparatus according to claim 16, comprising a plurality of roller pairs, which are arranged in alternating orientation along a processing direction of the continuous band of wrapping material, such that the lateral areas of the wrapping material are alternately bent upwardly and downwardly.

22. The apparatus according to claim 21, wherein the consecutive pairs of rolls are positioned at different heights such that the wrapping material is also bent up and down in processing direction of the continuous band of wrapping material.

23. The apparatus according to claim 16, comprising a closing device for controlling the contact pressure between the one or more roller pairs and, preferably, wherein the closing device comprises adjustable resilient elements, preferably tension springs, for controlling the contact pressure between each roller pair.

24. The apparatus according to claim 16, further comprising a glue applicator, wherein the glue applicator is configured to apply glue to a lateral area of the continuous band of wrapping material that has been guided through the curved area of the roller gap.

25. A method for processing a band of wrapping paper, comprising the steps of: providing a continuous band of wrapping material, guiding the continuous band of wrapping material through a roller gap defined by a roller pair, wherein the roller pair comprises a male and a female roller, wherein both rollers have flat central roller areas, and wherein the female roller has convexly rounded edges, and the male roller has corresponding concavely rounded edges, wherein the rollers have matching convex and concave shapes, respectively, such that the rollers provide a continuous weakened region of the continuous band of wrapping material by displacing the region of the continuous band of wrapping material which is passing between the concavo-convex portion of the roller gap relative to the region of the continuous band of wrapping material which is passing between the flat central portion of the roller gap.

26. The method according to claim 25, wherein the rollers provide a continuous weakened lateral edge portion of the continuous band of wrapping material.

27. The method in accordance with claim 25, comprising the further step of: providing a plurality of roller pairs in alternating heights with respect to the processing direction of the continuous band of wrapping material.

28. The method in accordance with claim 25, comprising the further step of: controlling the contact pressure between the one or more roller pairs via a closing device.

Description

[0051] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0052] FIG. 1 shows a prior art wrapping device;

[0053] FIG. 2 shows a female roller for use in the apparatus of the present invention;

[0054] FIG. 3 shows a male roller for use in the apparatus of the present invention;

[0055] FIG. 4 shows a cross-section of an assembled roller pair;

[0056] FIG. 5 shows an apparatus of the invention employing four roller pairs.

[0057] FIG. 1 shows a conventionally used wrapping device as known from US patent application No. 2016/0120216. In the apparatus disclosed therein, a flat continuous band of wrapping material is unwound from a material bobbin. The wrapping material is then conveyed past a glue applicator unit, via which seam glue is applied on a side area of the wrapping material. The band of wrapping material paper band is then wound around a rod shaped mandrel. A first roller having a convex or U-shaped roller surface presses the wrapping material against the mandrel. A further roller pair with each roller having a convex or U-shaped roller surface closes the wrapping material on itself, whereby the side of the wrapping material with the seam glue is adhered to the other side of the wrapping material. The seam glue is then cured in a downstream heating device.

[0058] In FIGS. 2 and 3 suitable rollers for the apparatus for treating wrapping material according to the present invention are depicted. The roller depicted in FIG. 2 is a female roller 20 having a generally flat central roller surface area 22 with convexly rounded edges 24. The diameter 26 of the female roller 20, measured at the flat central surface area 22, amounts to 30 millimeters. The overall width of the roller is 26 millimeter. The width of the central roller surface 22 amounts to 20 millimeters. Each of the two edges 24 of the female roller 20 exhibit a convex curvature having a radius of 3 millimeters.

[0059] The roller depicted in FIG. 3 is a male roller 30, whose roller surface matches the roller surface of the female roller 20 of FIG. 2. The male roller 30 has a generally flat central roller surface area 32 with concavely rounded edges 34. The diameter 36 of the male roller 30, measured at the flat central surface area 32, also amounts to 30 millimeters. The overall width of the roller is 26 millimeter. The width of the central roller surface area 32 amounts to 20 millimeters. Each of the two edges 34 of the male roller 30 exhibit a concave curvature having a radius of 3 millimeters.

[0060] In the apparatus 10 of the present invention the two rollers 20, 30 depicted in FIGS. 2 and 3 are mounted adjacent to each other so as to define a roller gap 12 there between as shown in FIG. 4. Each of the rollers 20, 30 is rotatably mounted to a corresponding roller support plate 14a, b. In the embodiment depicted in FIG. 4 the rollers 10, 30 are each set on two ball bearings 16 and are mounted to the support plates 14a, b via central screws 18. The central screws 18 also define the rotational axes of the rollers 20, 30.

[0061] The support plates 14a, b are mounted to an adjustable closing device (not shown in FIG. 4) which allows controlling the contact pressure between the rollers 20, 30.

[0062] In use of the apparatus 10, a continuous band of wrapping material is fed in processing direction of the wrapping material into the roller gap 12 defined by the roller pair 20, 30. In the configuration of FIG. 4 the processing direction is perpendicular to the drawing plane. Due to the special design of the roller gap 12, the lateral areas of the wrapping material are pressed and bent downwardly in the configuration as depicted in FIG. 4.

[0063] The wrapping material 40 may for example be a conventionally used wrapping paper. By bending and pressing the edges of the wrapping paper, the wrapping paper is prepared to adopt a round shape of the final product. Further bending and pressing the lateral regions of the wrapping paper weakens the internal structure of the wrapping paper. In particular stiff paper fibers oriented perpendicular to the processing direction of the wrapping paper are broken or weakened such that the overall softness of the wrapping paper is increased.

[0064] In FIG. 5 an apparatus 10 for treating wrapping material comprising four roller pairs 42, 44, 46, 48 is depicted. The roller pairs 42, 44, 46, 48 are sequentially arranged along the processing direction (indicated by the arrow) of the wrapping material 40, whereby consecutive roller pairs 42, 44, 46, 48 have alternating orientation. In processing direction of the wrapping paper, the first and the third roller pair 42, 46 are oriented such that the female roller 20 is located on top, while the second and the forth roller pair 44, 48 is orientated the other way around with the male roller 30 being located on top.

[0065] The upper rollers of each roller pair 42, 44, 46, 48 are all mounted to the upper support plate 14a, while the lower rollers of each roller pair 42, 44, 46, 48 are mounted to the lower support plate 14b. Upper and lower support plates 14a, 14b are adjustably mounted to a closing device 50, via which a contact pressure between the roller pairs 42, 44, 46, 48 may be adjusted. In the embodiment of FIG. 5 the closing device 50 comprises two adjustable tension springs 52 that allow controlling the contact pressure of the roller pairs 42, 44, 46, 48.

[0066] The rotational axes of the upper and the lower rollers are all mounted at the same height. Thus, the central portion of the wrapping material 40, that is the portion of the wrapping material 40 that is guided over the flat central surfaces 22, 32 of the rollers 20, 30 passes the apparatus 10 in a constant height and, thus, without being significant affected by the apparatus 10.

[0067] Due to the alternating orientation of the roller pairs 42, 44, 46, 48, the lateral regions of the wrapping paper 40, are alternately bent upward and downward. By this repeated up- and downward bending the rigidity of the lateral areas of the wrapping material 40 is reduced. Thus, the lateral areas of the wrapping material 40 are significantly softened and the wrapping material 40 is therefore well prepared for being formed into a rod shape by a downstream wrapping unit (not shown).

[0068] As mentioned above, in the embodiment of FIG. 5 the axes of the upper rollers are positioned at the same height and the axes of the lower rollers are positioned at the same height, respectively. Accordingly, the central areas of the wrapping material 40 are pulled at the same height through the apparatus 10. In an alternative embodiment (not shown) the roller pairs 42, 44, 46, 48 may also be alternately positioned at different heights such that the complete wrapping material 40 alternately travels upward and downward when being pulled through the apparatus 10. By positioning the roller pairs 42, 44, 46, 48 at different heights the wrapping material 40 is also bent in processing direction, which may further increase flexibility of the wrapping material 40.

[0069] As indicated above the present invention is particularly useful for treating wrapping paper. By positioning the roller pairs 42, 44, 46, 48 in alternating orientation and by additionally positioning the roller pairs 42, 44, 46, 48 at different heights, it is possible to simultaneously soften the wrapping paper fibers that are oriented perpendicular to the processing direction and also the wrapping paper fibers that are oriented in parallel to the processing direction of the continuous band of wrapping paper.

[0070] The exemplary embodiments described above illustrate but are not limiting. In view of the above discussed exemplary embodiments, other embodiments consistent with the above exemplary embodiments will now be apparent to one of ordinary skill in the art.