Improvement in cylinder for tissue paper lamination

Description

Field of the Invention

[0001] The present invention relates to the method for tissue paper lamination, that combines DESL and Point to Point processes, technical and functional improvements in a cylinder that combines two types of lamination typically made exclusively with different rollers.

Background of the Invention

[0002] As is well known, the tissue paper, due to its peculiar characteristics, is widely used in different products, especially toilet paper, paper towels and napkins paper; however, to enhance the quality of such products, they undergo by laminating process, which traditionally can vary according to the product to be obtained.

[0003] Although there are several lamination processes, two of them are highlighted and given different designations such as: DESL and Point to Point, whereas they are more suitable for the production of toilet paper, paper towels and napkins paper, or others with the same characteristics.

[0004] The Point to Point lamination process is carried out between two synchronized steel cylinders, with extremely accurate rollers having less than 0.01 mm of roundness and less than 0.005 mm of ovalization, which allow a large volume of semi-finished product as toilet paper and paper towel, due to the cells structure. A padded is created, but it gives a flat appearance to the laminated paper.

[0005] DESL laminating process is carried out in a calendering roll called Marrying roll. The cylinders elements are slotted and synchronized so that the male elements (high-relief) fit into the female parts (low-relief). This system generates a smaller volume on paper than Point to Point system, but it provides a 3D appearance with the impression of a larger volume.

[0006] It is known the PCT application WO02/068758 "A sheet of creped and embossed absorbent paper, an embossing roll for one such sheet and an embossing method" of 2002 which describes an embossed sheet consisting of at least two plies of creped cellulose wadding. The first play comprises a first embossing pattern made up of a first series protrusions which form first alignments and their peaks are linked to the inner face of the second ply, facing to each other. Both plies comprise the second embossing pattern made up of a second series of second protrusions of first play extend opposite and close to the peaks of the second protrusions of the second ply.

[0007] Other document, PCT application WO02/42558 "Absorbent creped paper sheet comprising a background pattern and a main decorative pattern, and embossing roll and method for making such a sheet" of 2001 refers to an embossed sheet consisting of at least a cotton-wool-like cellulose ply comprising an embossing pattern with first series pf protuberances projecting on one surface of the ply. Each protuberance of the first series comprises a polyhedral frustum and a flattened free end section with rounded edges.

[0008] Finally, European patent EP1081284 "Absorbent paper product comprising at least three plies, and process for making the same" of 1999 describes a product made of absorbent paper with a mass per unit area or gram weight of about 36 to about 105 g/cm2, comprising at least three plies: two embossed external plies, lower and upper, each comprising patterns in relief consisting at least partly of discrete protuberances, and a central ply, wherein the distal surfaces of at least a part of the protuberances of each of said external plies are turned towards the central ply, and wherein at least one of the external folds has a pattern density higher than 30 protuberances / cm2, wherein the lower embossed external ply has a first and a second pattern, the second pattern having a height lower than the first pattern, wherein the central ply and the upper embossed external ply are associated with said lower embossed external ply in a so-called "nested" manner, at the level of at least a part of the tips of the first pattern of the lower embossed external ply.

Description of the Invention

[0009] The main objective of the present invention is a method for tissue paper lamination, that combines DESL process and Point to Point process, resulting in technical and functional improvements in a cylinder by combining two types of lamination process made exclusively with different rollers, consequently, the said improvement solves the problems or drawbacks of merging these two outcomes features on paper, which are volume and 3D appearance. The precision of adjustments on engraved cylinder is ensured through innovative processes in the manufacture of cylinders, despite having higher elements for the simulation of DESL.

[0010] The innovation in the production process and timing adjustments of the cylinders allow innovative results in the field of tissue and paper converting. The combination of these two technologies has not yet been presented in the market.

Description of the drawings

[0011] For a better understanding of the present invention, a detailed description thereof is shown below, referring to the attached drawings:

FIGURES 1A and 1B represent schematic views highlighting the DESL tissue paper lamination process;

FIGURES 2A and 2B represent schematic views as well, however, highlighting Point to Point tissue paper lamination process; and

FIGURE 3 illustrates a schematic view of the cylinders according to the invention that simultaneously combine the two processes.

Detailed description of the invention

[0012] According to these illustrations and their details, particularly figures 1A, 1B, 2A and 2B, the present Invention includes two known technologies for embossing, one named DESL (1), and the other, Point to Point (2), wherein the former provided to the paper a smaller volume than Point to Point process, but provides a 3D appearance with the impression of a larger volume, while the latter provides a large volume of semi-finished product such as toilet paper and paper towels, due to cells structure.

[0013] On Figures 1A and 1B it is schematically shown the DESL process (1), whereby it can be seen that the two paper layers (3, 4) pass through their respective embossing cylinders (5, 6), which jointly operate with calendering rolls (7, 8, 9), and other sizing rolls (10) so that after the embossing of the paper layers (3, 4), the same overlap to form a double overlying layer (11), defining a lamination which is held in a calendering roll (8) called Marrying roll, and at this point, the elements of cylinders are slotted, but synchronized, where the male elements (high relief) (12) fit into female elements (low relief) (13), resulting in a smaller volume in double paper (11) when compared with the Point to Point process (2), but providing a 3D appearance, creating the impression of a larger volume.

[0014] On Figures 2A and 2B it is schematically illustrated the Point to Point process (2), where it can be seen that the two paper layers (3, 4) pass through their respective embossing cylinders (14, 15), which operate in conjunction with calendering rolls (16, 17) and other sizing rollers (18), such that after the embossing of the paper layers (3 and 4) the same overlap to form a double overlying layer (19) where reliefs of one paper and another have male elements glued on top (20) forming overlapped dots, while the female elements are combined to form a hollow portion (21), producing a padded effect, but giving a flat appearance to double-laminated paper.

[0015] Therefore, the Point to Point process is a lamination between two synchronized steel cylinders (14, 15), both extremely accurate having less than 0.01 mm of roundness and less of 0.005 mm of ovalization, which allow a large volume of semi-finished product as toilet paper and paper towels, due to cells structure, creating a padded, but with a flat appearance to the laminated paper.

[0016] As illustrated on Figure 3, the present invention is characterized by the fact that it comprises an embossing cylinder (22) which includes a combined DESL (1) and Point to Point (2) embossing process and, for this purpose, higher elements (23) are provided to DESL process and lower elements (24) for Point to Point process, wherein top surfaces of the relief formed by lower elements (24) of second embossing cylinder (22) are glued to the top surfaces of the relief formed by of the first embossing cylinder such that reliefs formed by the elements of the first embossing cylinder are fitted with the reliefs formed by higher elements (23) of the second embossing cylinder, such elements forming various reliefs on paper surface and can compose figures, ribbing and all sorts of drawings.

[0017] The combination of both systems into a cylinder (22) definitely solves the problems and drawbacks of two processes by combining these two outcomes features in paper, such as volume and 3D appearance. The precision of adjustments on engraved cylinder is ensured through innovative processes in the manufacture of cylinders, having higher elements for simulating DESL process.

[0018] It will be understood that certain characteristics and combinations of embossing rollers and cylinders, as well as the sizing systems, may considerably vary while maintaining the same functional concept for the assembly, consequently the embodiment herein described in detail by way of example is clearly open to constructive variations, but always within the scope of the inventive concept herein described of an embossing cylinder (22), which includes combined DESL (1) and Point to Point (2) lamination process, and as many modifications can be made on herein detailed configuration according to the descriptive requirements of the law, it is understood that the present details should be interpreted in an illustrative and not limiting manner.

Claims

1. Method for tissue paper lamination, that combines DESL process (1), and Point to Point process (2), wherein, the first paper layer (3) passes through its respective first embossing cylinder (5, 14) comprising elements of cylinders, the second paper layer (4) passes through its respective second embossing cylinder (6, 15, 22), the two paper layers (3, 4) jointly operate with calendering rolls (7, 8, 16, 17) and other sizing rollers (10, 18), wherein after the embossing of the first and second paper layers (3, 4), the said layers (3, 4) overlap characterized in that the second embossing cylinder (22) comprises combination of higher elements (23) for DESL process and lower elements (24) for Point to Point process, wherein top surfaces of the relief formed by lower elements (24) of second embossing cylinder (22) are glued to the top surfaces of the relief formed by the elements of the first embossing cylinder (5,14) such that reliefs formed by the elements of the first embossing cylinder are fitted with the reliefs formed by higher elements (23) of the second embossing cylinder (22) forming several reliefs on paper surface composing figures, ribbing and all sorts of drawings.

Ansprüche

1. Verfahren zum Tissue-Papier-Laminieren, bei dem ein DESL-Verfahren (1) und ein Punkt-zu-Punkt-Verfahren (2) kombiniert werden, wobei eine erste Papierschicht (3) einen jeweils ersten Prägezylinder (5, 14), der Elemente von Zylindern aufweist, passiert, wobei eine zweite Papierschicht (4) einen jeweils zweiten Prägezylinder (6, 15, 22) passiert, wobei die beiden Papierschichten (3, 4) gemeinsam mit Kalanderwalzen (7, 8, 16, 17) und anderen Schlichtwalzen (10, 18) bearbeitet werden, wobei die Schichten (3, 4) nach dem Prägen der ersten und der zweiten Papierschicht (3, 4) einander überlappen, dadurch gekennzeichnet, dass der zweite Prägezylinder (22) eine Kombination aus höheren Elementen (23) für den DESL-Prozess und niedrigeren Elementen (24) für den Punkt-zu-Punkt-Prozess aufweist, wobei Oberflächen eines von niedrigeren Elementen (24) des zweiten Prägezylinders (22) gebildeten Reliefs mit Oberflächen eines von Elementen des ersten Prägezylinders (5, 14) gebildeten Reliefs verklebt werden, so dass Reliefs, die von den Elementen des ersten Prägezylinders gebildet werden, mit den Reliefs, die von den höheren Elementen (23) des zweiten Prägezylinders (22) gebildet werden, verbunden werden, um mehrere Reliefs auf der Papieroberfläche zu formen, die Figuren, Rippen und alle Arten von Zeichnungen ausbilden.

Revendications

1. Procédé de laminage de papier à usage sanitaire, combinant la technologie DESL (1) et un procédé de collage pointe à pointe (2), dans lequel le premier plis de papier passe au travers de son respectif premier cylindre de gaufrage (5, 14) comprenant des éléments des cylindres, le deuxième plis de papier passe au travers de son respectif deuxième cylindre de gaufrage (6, 15, 22), les deux plis de papier (2, 4) fonctionnent conjointement avec des rouleaux de calandrage (7, 8, 16, 17) et d'autres rouleaux ensimeurs (10, 18), dans lequel, suite au laminage du premier et du deuxième plis de papier (3, 4) lesdits plis (3, 4) se superposent ; caractérisé en ce que le deuxième cylindre de gaufrage (22) comprend une combinaison d'éléments plus hauts (23) pour le procédé utilisant la technologie DESL et d'éléments plus bas (24) pour le procédé de collage pointe à pointe, dans lequel les superficies supérieures du relief formé par les éléments plus bas (24) du deuxième cylindre de gaufrage (22) sont collés sur les superficies supérieures du relief formé par les éléments du premier cylindre de gaufrage (5, 14) de sorte que les reliefs formés par les éléments du premier cylindre de gaufrage s'engagent dans les reliefs formés par les éléments plus hauts (23) du deuxième cylindre de gaufrage (22), formant plusieurs reliefs sur la superficie du papier figures, des nervures et toutes sortes de dessins.

Drawing