APPARATUS AND METHOD FOR MANUFACTURING A TISSUE PAPER PRODUCT

Abstract

This disclosure relates to an apparatus for manufacturing a tissue paper product, such as toilet paper or household towel. The apparatus comprises an embossing unit comprising a first counter roll, a first heatable embossing roll, a second counter roll, and a second heatable embossing roll, and a marrying roll. The apparatus is configured to emboss a first ply between the first heatable embossing roll and the first counter roll, to emboss a second ply between the second heatable embossing roll and the second counter roll, and to ply-bond the first ply and the second ply between the first heatable embossing roll and the marrying roll.

Claims

1-29. (canceled)

30. An apparatus for manufacturing a tissue paper product, such as toilet paper or household towel, the apparatus comprising: an embossing unit comprising a first counter roll, a first heatable embossing roll, a second counter roll, and a second heatable embossing roll, and a marrying roll, wherein the apparatus is configured to emboss a first ply between the first heatable embossing roll and the first counter roll, and to emboss a second ply between the second heatable embossing roll and the second counter roll, and to ply-bond the first ply and the second ply between the first heatable embossing roll and the marrying roll, and the apparatus is configured to process at a ply speed in a range of 300 m/min to 700 m/min, wherein, optionally, the first heatable embossing roll and the second heatable embossing roll are synchronizeable for ply-bonding the first ply and the second ply with a nested embossment structure or a tip-to-tip bonding structure.

31. The apparatus for manufacturing a tissue paper product of claim 30, wherein the embossing unit is configured to receive the first ply with the first counter roll, to convey the first ply between the first counter roll and the first heatable embossing roll, and to further convey the first ply with the first heatable embossing roll, and wherein the embossing unit is configured to receive the second ply with the second counter roll, to convey the second ply between the second counter roll and the second heatable embossing roll, and to further convey the second ply with the second heatable embossing roll, wherein the embossing unit is configured to convey the first ply and the second ply between the first heatable embossing roll and the marrying roll.

32. The apparatus for manufacturing a tissue paper product of claim 30, wherein the embossing unit comprises an adhesive supplying unit for applying adhesive, such as lamination glue, to the first ply and/or to the second ply, the apparatus optionally being configured to supply the adhesive to at least a part of the tips of embossments formed on the first ply or the second ply, wherein the adhesive supplying unit is optionally configured to supply adhesive to the first ply while the first ply is being conveyed by the first heated embossing unit prior to the ply-bonding, and/or wherein the adhesive supplying unit is optionally configured to supply adhesive to the second ply while being conveyed by the second heated embossing unit prior to the ply-bonding.

33. The apparatus for manufacturing a tissue paper product of claim 32, wherein the adhesive supplying unit comprises an applicator roll for transferring adhesive to the first ply or the second ply, and an anilox roll for dosing adhesive and transferring the adhesive to the applicator roll, wherein the anilox roll is engraved with cavities for receiving respective dosages of adhesive.

34. The apparatus for manufacturing a tissue paper product of claim 30, the apparatus being configured to process at a ply speed in a range of 400 m/min to 700 m/min.

35. The apparatus for manufacturing a tissue paper product of claim 32, wherein the adhesive supplying unit is configured to supply adhesive to the first ply while the first ply is being conveyed by the first heatable embossing roll.

36. The apparatus for manufacturing a tissue paper product of claim 30, wherein the first counter roll, the second heatable embossing roll, and the marrying roll are rotatable in one direction and the second counter roll and the first heatable embossing roll are rotatable in another direction, opposite to the one direction.

37. The apparatus for manufacturing a tissue paper product of claim 30, wherein the first heatable embossing roll is configured to form first embossments with a height in a range of 0.2 mm to 2.0 mm on the first ply, and the second heatable embossing roll is configured to form second embossments with a height in a range of 0.2 mm to 2.0 mm on the second ply, and wherein the first heatable embossing roll is optionally configured to also form third embossments with a height that is smaller than the height of the first embossments, and/or wherein the second heatable embossing roll is optionally configured to also form fourth embossments with a height that is smaller than the height of the second embossments.

38. The apparatus for manufacturing a tissue paper product of claim 37, wherein the first heatable embossing roll is configured to form the first embossments with a height of 0.1 mm to 1.2 mm on the first ply, and the second heatable embossing roll is configured to form the second embossments with a height of 0.2 mm to 2.0 mm on the second ply, wherein the height of the second embossments is larger than the height of the first embossments.

39. The apparatus for manufacturing a tissue paper product of claim 30, wherein the first heatable embossing roll is configured to be heated to a steady-state temperature in the range of 80° C. to 170° C., optionally 100° C. to 165° C., or 110° C. to 165° C., and/or wherein the second heatable embossing roll is configured to be heated to a steady-state temperature in the range of 80° C. to 170° C., optionally 100° C. to 165° C., or 110° C. to 165° C.

40. The apparatus for manufacturing a tissue paper product of claim 39, wherein the first heatable embossing roll is configured to be heated to a steady-state temperature in the range of 120° C. to 160° C., or optionally 130° C. to 155° C., and wherein the second heatable embossing roll is configured to be heated to a steady-state temperature in the range of 120° C. to 160° C., or optionally 130° C. to 155° C.

41. The apparatus for manufacturing a tissue paper product of claim 30, the apparatus further comprising at least one multi-ply-bonding unit configured to ply-bond a two-ply product formed by the embossing unit with at least one additional ply.

42. The apparatus for manufacturing a tissue paper product of claim 30, the apparatus further comprising at least one wetting unit configured to wet at least one ply before the at least one ply is received by the embossing unit, the wetting unit optionally being configured to provide a liquid, such as water, to the at least one ply with an amount of liquid in the range of 2% to 12% of the basis weight of the at least one ply, or optionally 4% to 10% of the basis weight of the at least one ply.

43. The apparatus for manufacturing a tissue paper product of claim 30, the apparatus lacking a wetting unit for providing a liquid to any of the plies.

44. A machine for manufacturing a roll of a tissue paper product, the machine comprising the apparatus of claim 30, the machine further comprising a roll forming unit for winding up a final product and forming a roll of absorbent sheet product, the roll forming unit optionally comprising a mandrel that is axially elastic, the material of the mandrel optionally being flexible and elastic.

45. A method of manufacturing a tissue paper product, such as toilet paper or household towel, comprising at least two plies, comprising the steps of: feeding at least a first ply and a second ply, with a basis weight in a range of 13 to 30 g/m.sup.2, optionally from 16 to 28 g/m.sup.2, or from 18 to 24 g/m.sup.2 or from 18 to 22 g/m.sup.2, respectively; receiving the first ply and the second ply by an embossing unit comprising a first counter roll, a first heatable embossing roll heated to a steady-state temperature in a range of 80° C. to 170° C., a second counter roll, a second heatable embossing roll heated to a steady-state temperature in a range of 80° C. to 170° C., and a marrying roll; embossing the first ply between the first heatable embossing roll and the first counter roll and embossing the second ply between the second heatable embossing roll and the second counter roll; ply-bonding the first ply and the second ply between the first heatable embossing roll and the marrying roll; wherein, optionally, the first heatable embossing roll and the second heatable embossing roll are synchronized and the first ply and the second ply are ply-bonded with a nested embossment structure or a tip-to-tip bonding structure wherein the plies are processed at a speed in a range of 300 m/min to 700 m/min.

46. The method of manufacturing a tissue paper product of claim 45, comprising the steps of: receiving the first ply with the first counter roll; conveying the first ply between the first counter roll and the first heatable embossing roll; further conveying the first ply with the first counter roll; receiving the second ply with the second counter roll; conveying the second ply between the second counter roll and the second heatable embossing roll; further conveying the second ply with the second counter roll; and conveying the first ply and the second ply between the first heatable embossing roll and the marrying roll to ply-bond the first ply and the second ply with each other; wherein the first counter roll, the second heatable embossing roll, and the marrying roll are rotated in one direction and the second counter roll and the first heatable embossing roll are rotated in another direction, opposite to the one direction.

47. The method of manufacturing a tissue paper product of claim 45, the method further comprising the step of applying an adhesive, such as lamination glue, to the first ply and/or to the second ply, prior to the step of ply-bonding the first ply and the second ply, wherein the adhesive is optionally supplied to at least a part of the tips of embossments formed on the first ply or the second ply, wherein the adhesive is optionally supplied to the first ply while the first ply is being conveyed by the first heated embossing unit prior to the ply-bonding, and/or wherein the adhesive supplying unit is optionally configured to supply adhesive to the second ply while being conveyed by the second heated embossing unit prior to the ply-bonding.

48. The method of manufacturing a tissue paper product of claim 47, wherein the adhesive is transferred from an anilox roll, engraved with cavities for receiving respective dosages of adhesive and for dosage of adhesive to an applicator roll, and is supplied from the applicator roll to the first ply or the second ply.

49. The method for manufacturing a tissue paper product of claim 45, wherein the plies are processed at a speed in a range of 400 m/min to 700 m/min.

50. The method of manufacturing a tissue paper product claim 45, wherein the adhesive is supplied to the first ply while the first ply is being conveyed by the first heatable embossing roll.

51. The method of manufacturing a tissue paper product of claim 45, wherein the first ply is made of one of the materials selected from the group consisting of: CWP and structured tissue such as creped TAD, uncreped TAD, eTAD, NTT, and ATMOS; and wherein the second ply is made of one of the materials selected from the group consisting of: CWP and structured tissue such as creped TAD, uncreped TAD, eTAD, NTT, and ATMOS.

52. The method of manufacturing a tissue paper product of claim 45, the method comprising the steps of: feeding a third ply, optionally made of one of the materials selected from the group consisting of: CWP and structured tissue such as creped TAD, uncreped TAD, eTAD, NTT, and ATMOS; and ply-bonding the third ply with the first ply or the second ply, prior to or after the steps carried out in the embossing unit.

53. The method of manufacturing a tissue paper product of claim 45, wherein the first heatable embossing roll is heated to a steady-state temperature in the range of 80° C. to 170°, optionally 100° C. to 165°, or 110° C. to 165°; and/or wherein the second heatable embossing roll is heated to a steady-state temperature in the range of 80° C. to 170°, optionally 100° C. to 165°, or 110° C. to 165°.

54. The method for manufacturing a tissue paper product of claim 53, wherein the first heatable embossing roll is heated to a steady-state temperature in the range of 120° C. to 160° C., or optionally 130° C. to 155° C., and wherein the second heatable embossing roll is be heated to a steady-state temperature in the range of 120° C. to 160° C., or optionally 130° C. to 155° C.

55. The method of manufacturing a tissue paper product of claim 45, the method comprising a step of wetting the first ply and/or the second ply with a liquid prior to embossing the first ply and/or second ply in the embossing unit, the step of wetting optionally comprising adding the liquid, such as water, to the first ply and/or the second ply with an amount of liquid in the range of 2% to 12% of the basis weight of the first ply and/or the second ply, or optionally 4% to 10% of the basis weight of the first ply and/or the second ply.

56. The method of manufacturing a tissue paper product of claim 45, the method lacking a step of wetting a ply with a liquid.

57. The method of manufacturing a tissue paper product claim 45, wherein an embossing load during the embossing of the first ply and/or the second ply is in a range of 1 to 50 kg/cml, optionally in a range of 5 to 40 kg/cml.

58. The method of claim 45, wherein the first ply is provided with first embossments with a height in a range of 0.2 mm to 2.0 mm and/or with third embossments with a height in a range of 0.1 mm to 1.2 mm, and/or wherein the second ply is provided with second embossments with a height in a range of 0.2 mm to 2.0 mm and/or with fourth embossments with a height in a range of 0.1 mm to 1.2 mm.

59. A tissue paper product, such as toilet paper or household towel, manufactured according to the method of claim 45.

60. A roll of a tissue paper product, such as toilet paper or household towel, comprising the tissue paper product of claim 59, wherein a diameter of the roll is in a range of from 80 to 200 mm, optionally from 100 to 150 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0114] For a better understanding of the present disclosure and to show how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0115] The description is given with reference to the accompanying drawings, in which:

[0116] FIG. 1 depicts an embodiment of an embodiment of an apparatus for manufacturing a tissue paper product in accordance with the present disclosure; and

[0117] FIG. 2 is an enlarged part of a part of the apparatus of FIG. 1 showing how ply-bonding is carried out between a heatable embossing roll and a marrying roll.

[0118] FIG. 1 depicts an embodiment of an embodiment of an apparatus for manufacturing a tissue paper product in accordance with the present disclosure. To be more precise, FIG. 1 depicts an embossing unit of the apparatus.

[0119] The embossing unit shown in FIG. 1 comprises a first heatable embossing roll 40 and a second heatable embossing roll 60. The first heatable embossing roll 40 and the second heatable embossing roll 60 are both heatable to a temperature in a range of 80° C. to 170° C. with an inner heating means (not shown in FIG. 1 and provided inside of the first and second heatable embossing rolls 40, 60, respectively), heating the respective roll from the inside. In accordance with other embodiments, an outer heating means may be provided, which heats the respective roll from the outside. According to some embodiments, a roll may be heated both from the inside and from the outside.

[0120] The embossing unit further comprises a first counter roll 30 and a second counter roll 50.

[0121] When using the apparatus, and when using the embossing unit of FIG. 1, in particular, a first ply 10 is received by the first counter roll 30 and conveyed by the first counter roll 30, until the first ply 10 is embossed between the first counter roll 30 and the first heatable embossing roll 40. Although it is possible, in the case of this embodiment, not to heat the first heatable embossing roll 40, it is of particular interest to heat the first heatable embossing roll 40 to a temperature in the range of 80° C. to 170° C. and to heat-emboss the first ply 10 between the first counter roll 30 and the first heatable embossing roll 40. The first ply 10 is received at a processing speed D1 in the range of 200 m/min to 700 m/min.

[0122] When using the apparatus, and when using the embossing unit of FIG. 1, in particular, a second ply 20 is received by the second counter roll 50 and conveyed by the first counter roll 50, until the second ply 20 is embossed between the second counter roll 50 and the second heatable embossing roll 60. Although it is possible, in the case of this embodiment, not to heat the second heatable embossing roll 60, it is of particular interest to heat the second heatable embossing roll 60 to a temperature in the range of 80° C. to 170° C. and to heat-emboss the second ply 20 between the second counter roll 50 and the second heatable embossing roll 60. The second ply 20 is received at a processing speed D2 in the range of 200 m/min to 700 m/min.

[0123] Specifically, the apparatus of FIG. 1 allows synchronizing the first heatable embossing roll 40 and the second heatable embossing roll 60. For example, the first ply 10 and the second ply 20 are processed at the same processing speed D1 and D2 in the range of 200 m/min to 700 m/min. D1 and D2 may be the same or may be deviate from one another. The synchronization of the first heatable embossing roll 40 and the second heatable embossing roll 60 allows ply-bonding the first ply 10 and the second ply 20 in a next step in a nested manner, i.e., such that embossments on the first ply 10 and on the second ply 20 are nested (received in one another). Alternatively, the embodiment of FIG. 1 also allows to form a tip-to-tip bonding structure or to be operated without synchronization such that the plies are bonded, e.g., with a random nested structure.

[0124] The apparatus of FIG. 1 comprises a marrying roll 70 and is configured to ply-bond the first ply 10 and the second ply 20 between the first heatable embossing roll 40 and the marrying roll 70. At the right-hand side of FIG. 1, the nested embossment structure 110 of the ply-bonded product with two plies, conveyed at the processing speed D3, which is in this case equal to D1 and D2, is schematically shown.

[0125] FIG. 2 is an enlarged view of region X of FIG. 1, i.e., the region X where the ply-bonding of the first ply 10 and the second ply 20 is carried out. The first heatable roll 40 and the marrying roll 70 ply-bond the two plies 10, 20 such that the embossments are nested in one another. To ensure this, the first heatable roll 40 and the second heatable roll 60 are synchronized during the manufacturing process. This may imply that the processing speeds D1 and D2 are the same, or it may imply that the speeds D1, D2 differ.

[0126] Turning back to FIG. 1, it can further be seen that the embodiment of the apparatus comprises an adhesive supplying unit. The adhesive supplying unit supplies adhesive to the first ply 10 while the first ply 10 is being conveyed by the first heated embossing unit 40, just after the heat-embossing has taken place and prior to the ply-bonding with the second ply 20. The adhesive is thus supplied just shortly before the ply-bonding. This means that the heating of the first ply 10 does not negatively affect the ply-bonding process.

[0127] The adhesive is supplied to at least a part of the tips of the embossments formed between the first counter roll 30 and the first heatable embossing roll 30 on the first ply 10.

[0128] The adhesive supplying unit comprises an applicator roll 100 for homogeneously transferring adhesive to the first ply 10, and an anilox roll 90 for dosing adhesive and transferring the adhesive to the applicator roll 100. The anilox roll 90 is engraved with cavities (not shown in FIG. 1) for receiving respective dosages of adhesive from an adhesive storage part 80.

[0129] The tissue paper products comprising the two plies 10, 20 with the nested embossment structure 110 and formed using heat-embossing with the first heatable embossing roll 40 and the second heatable embossing roll 60 both heated to a temperature in a range of 80° C. to 170° C. while the heat-embossing is performed, may have a high CD (cross direction) and/or MD (main direction) tensile strength, large thickness and good absorption capacity, without lowering (or while hardly lowering) the softness, as compared to a respective reference product produced in an analogous manner with the exception of not using heat-embossing but embossing with a non-heated roll.

[0130] In the following, a number of comparisons between tissue paper products manufactured using an embodiment of an apparatus in accordance with the present disclosure and an embodiment of a method in accordance with the present disclosure with reference products will be discussed.

EXAMPLE 1

[0131] Household towel products made of two plies of Conventional Wet Press (CWP) paper were produced with a grammage of about 40 g/m.sup.2 using an apparatus in accordance with the present disclosure and, in particular, using an embossing unit with two heatable embossing rolls. Both rolls were heated to a temperature in the range of 100 ° C. to 150 ° C. The processing speed was in a range of 200 m/min to 700 m/min. The embossing load was varied, in order to make products of different thicknesses. Various properties of the manufactured tissue paper products were measured.

[0132] Both plies were embossed with an embossing density of 4 dots/cm.sup.2 and with embossment heights in a range of 0.8 mm to 1.4 mm. The embossments covered a surface area of the respective ply amounting to 5.2% of the total surface area of the respective ply.

[0133] A comparison was performed with reference products produced under the same conditions, with the exception of not heating any of the embossing rolls. It was found that the tissue paper product produced using the heated embossing rolls had a cross directional (CD) wet strength that was about 25% higher than the respective reference product.

[0134] Experimental results comparing the “reference products” and tissue paper products produced using embossing rolls to 100° C., 140° C., and 160° C. and having different thicknesses are shown in the following graph:

[0135] A comparison of the absorption capacities (measured in g/g) is shown in the following graph:

EXAMPLE 2

[0136] Household towel products made of two plies of TAD paper were produced with a grammage of about 40 g/m.sup.2 using an apparatus in accordance with the present disclosure and, in particular, using an embossing unit with two heatable embossing rolls. Both rolls were heated to a temperature in the range of 100° C. to 150° C. The processing speed was in a range of 200 m/min to 700 m/min. The embossing load was varied, in order to make products of different thicknesses. Both plies were embossed with an embossing density of 4 dots/cm.sup.2 and with embossment heights in a range of 0.8 mm to 1.4 mm. The embossments covered a surface area of the respective ply amounting to 5.2% of the total surface area of the respective ply. Various properties of the manufactured tissue paper products were measured.

[0137] A comparison was performed with reference products produced under the same conditions, with the exception of not using any heated embossing rolls. It was found that the tissue paper product produced using the heated embossing rolls had a cross directional (CD) wet strength that was about 5-10% higher than the respective reference product.

[0138] Experimental results comparing the “reference products” and tissue paper products produced using embossing rolls to 100° C., 140° C., and 160° C. and having different thicknesses are shown in the following graph:

[0139] Additional comparisons were made between analogous products which were produced using an additional step of wetting the plies with water (with 1.5 g/m.sup.2 per ply) during the manufacturing process:

[0140] Also in this case, an increase of the CD strength of about 5-10% as compared to reference products was observed. The following graphs compares the geometric tensile strength (GMT) of products produced without wetting the plies, products produced with plies wet with 0.5 g/m.sup.2 of water per ply water, and products produced with plies wet with 1.5 g/m.sup.2 of water per ply:

[0141] The experimental results are summarized in the following table:

TABLE-US-00001 Thickness gain at similar Absorption gain at similar CD CD wet versus no nested wet versus no nested heating cylinder (%) heating cylinder (%) CWP 10% 15% TAD  5%  4% CD wet gain at thickness Absorption at thickness constant versus no nested constant versus no nested heating cylinder (%) heating cylinder (%) CWP 25%  6% TAD 22%  1%

[0142] Moreover, the reduction of the softness compared to the respective reference products was evaluated:

TABLE-US-00002 Softness point reduction CWP −0.5 (from 4.5 to 4) TAD −0.5 (from 7 to 6.5) CWP −0.5 (from 4.5 to 4) TAD −0.5 (from 7 to 6.5)

[0143] It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed devices and systems without departing from the scope of the disclosure. Other aspects of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the features disclosed herein. It is intended that the specification and examples be considered as exemplary only. Many additional variations and modifications are possible and are understood to fall within the framework of the disclosure.