A multi-purpose embossing device for tissue paper

Abstract

The utility model discloses a multipurpose embossing device suitable for household paper, including at least three groups of independent setting's pre -embossing roller group and a group of composite roller group, each group pre -embossing roller group corresponds to one way raw paper respectively, and can selectivity carries out embossing treatment to its corresponding raw paper to form the embossed paper with the bottom line pattern, the composite roller group is used for carrying out the composite to at least two ways embossed paper from preceding at least two groups of pre -embossing roller group, or at least one way preceding embossed paper and at least one way unembossed raw paper carry out the composite, therefore, can according to actual production demand, and select the suitable pre -embossing roller group and composite roller group of quantity to realize the paper product satisfying different embossing demand, flexible and changeable, effectively reduce production cost.

Description

Technical Field

[0001] This utility model relates to the technical field of tissue paper processing, and in particular to a multi-purpose embossing device suitable for tissue paper. Background Technology

[0002] In the field of household paper, the embossing process commonly used in multi-layer paper materials (such as facial tissues, toilet paper, and wiping paper) mainly involves the pressing action of embossing rollers and rubber rollers to form embossed patterns on the base paper, thereby improving the paper's aesthetics, cleaning ability, and wiping effect. However, the traditional embossing process has certain requirements for the basis weight of the base paper, requiring the use of medium to high basis weight base paper of 15-20 g / m², resulting in high manufacturing costs for the finished paper.

[0003] However, for low-grammage paper (typically thin base paper with a specified weight of 8-20 g / m² and a thickness of only 0.07-0.13 mm), the manufacturing cost is lower than that of medium- and high-grammage base paper of 15-30 g / m². However, the fundamental compatibility barrier when performing embossing processes on this type of low-grammage paper has led to its long-standing reputation as "unable to be effectively embossed," as specifically manifested in the following ways: The contradiction between the physical properties of low-basis-weight paper and embossing processes The core physical characteristics of low-grammage paper (sparse fibers, low strength, and poor toughness) are incompatible with the mechanical requirements of the embossing process: 1) Fragile fiber structure: Low-grammage paper is made of short fibers randomly interwoven, and the bonding force between fibers is weak. During embossing, the local pressure applied by the embossing roller convex points can easily cause fiber breakage, forming a "press-through" defect; 2) Poor thickness uniformity: The thickness of low-grammage paper fluctuates greatly, and the gap between the embossing roller and the rubber roller is difficult to precisely match the paper thickness, resulting in insufficient pressure in some areas and excessive pressure in others (press-through), making it impossible to form a uniform embossing structure; 3) Weak resilience: The fiber elastic modulus of low-grammage paper is low, and the fibers are prone to plastic deformation after embossing. The embossing points are prone to collapse, making it impossible to form a stable "convex-concave" structure.

[0004] 2. Limitations of the adaptability of existing embossing techniques Traditional embossing processes (suitable for medium-to-high basis weight paper materials, such as 15-30 g / m²) achieve embossing through methods such as "steel-to-glue" and "convex-concave embossing." However, when this technology is directly applied to low basis weight paper materials, it has the following fatal flaws: 1) Embossing parameter mismatch: The design of the raised dots on the traditional embossing rollers is seriously mismatched with the thickness of low basis weight paper materials (0.07-0.13 mm)—the height of the raised dots is much greater than the thickness of the paper. Not only are the tips of the raised dots prone to piercing the paper during embossing, but there is also a great difficulty in matching the pressure between the rollers, increasing the manufacturing difficulty; 2) 1) Traditional embossing has a large area, and after embossing, the paper not only has a large shadow of the embossed pattern, resulting in a poor visual effect, but also has problems such as hard touch, grainy texture, and poor water absorption; 2) Limited functional expansion: Low basis weight paper is difficult to form an effective embossing structure (such as raised dots with a depth ≥0.4mm), and cannot improve the interlayer bonding of glue-free composite through embossing (under traditional processes, the anti-delamination strength of glue-free composite is only 0.2N / 15mm), and can only rely on high-cost processes (such as adhesive composite) or sacrifice functions (such as abandoning embossing).

[0005] However, in recent years, driven by the trends of "lightweight" and "environmentally friendly", the market demand for low-grammage paper materials has surged. However, existing technologies cannot solve the problems of its composite and embossing, which leads to limited product performance and inability to meet market demand.

[0006] 3. Limitations of the versatility of traditional embossing equipment Traditional embossing equipment is generally designed according to the principle of "dedicated machine for dedicated use," with its core working components (such as embossing rollers and transmission systems) highly bound to specific product specifications and processing techniques. For example, for shallow embossing equipment used on two-way thin paper, the roller hardness, pressure parameters, and feed speed are all fixed configurations. If it is necessary to switch to deep embossing technology for multi-layer composite paper, or to adjust the complexity of the texture pattern (such as switching from simple lines and stripes to three-dimensional embossed patterns), the core structure of the equipment cannot be compatible. This binding relationship means that a single machine can only meet the production needs of a single or limited range, making it difficult to cope with the "multi-variety" product iteration trend in the paper products market, resulting in extremely poor versatility. When there are slight adjustments to product specifications or process requirements, traditional equipment needs to switch processes by "changing rollers," but this process has significant operational pain points. Specifically, changing rollers requires multiple steps, including stopping the machine, disassembling the old roller, cleaning the roller shaft, installing the new roller, calibrating parallelism, and adjusting pressure parameters. A single operation usually takes 1-2 hours and requires extremely high operator skills. Frequent roller changing operations not only cause a lot of ineffective downtime and reduce equipment uptime, but also increase product defect rate due to human error, further increasing production costs.

[0007] Secondly, for production needs that involve significant differences across product series (such as switching from three-layer embossing to five-layer embossing), simple roller changing operations are no longer sufficient to meet process compatibility requirements. Companies often need to purchase dedicated embossing equipment as an alternative. This directly leads to two problems: firstly, a significant increase in equipment purchase costs; and secondly, increased complexity in equipment management, as multiple dedicated machines require more production space, driving up both space and labor costs. Equipment idle rates also rise, resulting in resource waste.

[0008] Therefore, developing a multi-purpose embossing device that can adapt to low-grammage base paper, integrate embossing and composite functions, and improve product performance has become an urgent technical problem to be solved. Utility Model Content

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-purpose embossing device suitable for household paper, which can achieve efficient embossing and lamination of low-grammage thin base paper, while taking into account pattern clarity, interlayer bonding strength and production economy.

[0010] To achieve the above objectives, this utility model provides a multi-purpose embossing device suitable for household paper, comprising at least three independently arranged pre-embossing roller groups and a composite roller group. Each pre-embossing roller group corresponds to a source of base paper and can selectively emboss the corresponding base paper to form embossed paper with a background pattern. The composite roller group is used to combine at least two sources of embossed paper from the aforementioned at least two pre-embossing roller groups, or to combine at least one source of embossed paper with at least one source of unembossed base paper. Each pre-embossing roller group includes a pre-embossing back roller and a pre-embossing roller that are closely fitted together. The surface of the pre-embossing roller is provided with raised textures that match the background pattern. The pre-embossing back roller is positioned to the side of the pre-embossing roller to form a vertically or obliquely arranged embossing channel, thereby allowing the corresponding base paper to pass vertically or obliquely through the embossing channel.

[0011] Furthermore, the composite roller assembly includes a composite pressure roller and a composite back roller that are closely fitted together.

[0012] Furthermore, the composite roller assembly also includes a composite rubber roller that closely cooperates with the composite pressure roller, wherein at least one path of base paper or embossed paper is embossed between the composite pressure roller and the composite rubber roller to form a layered pattern in a localized area of ​​the base paper or embossed paper, and then is laminated with other paths of base paper or embossed paper between the composite back roller and the composite pressure roller.

[0013] Furthermore, the surface of the composite pressure roller is provided with composite bosses that can respectively cooperate with the composite rubber roller and the composite back roller. The composite bosses cooperate with the composite rubber roller to emboss at least one path of base paper or at least one path of embossed paper, so that the base paper or embossed paper locally forms a layered pattern. Then, the base paper or embossed paper is laminated with other paths of base paper or embossed paper between the composite bosses of the composite pressure roller and the composite back roller.

[0014] Furthermore, the raised texture is composed of a plurality of embossed protrusions, and the embossed protrusions satisfy the following characteristics: • The total area of ​​all embossed protrusions within a unit square decimeter accounts for 13-20% of the total area. • The area of ​​each embossed boss is 0.015-0.23 mm². 2 .

[0015] Furthermore, an electrostatic elimination device is provided between the pre-embossing roller group and the composite roller group for electrostatic treatment of the surface of the pre-embossed paper.

[0016] The advantages of this utility model using the above-mentioned solution are as follows: 1) Multifunctional integration: According to actual production needs, an appropriate number of pre-embossing roller groups and composite roller groups can be selected to achieve paper products that meet different embossing requirements, making it flexible and versatile, and effectively reducing production costs. 2) The prepared paper products have the advantages of being soft to the touch, thick, and highly absorbent. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a multi-purpose embossing device.

[0018] Figure 2 A schematic diagram of the multi-purpose embossing device for implementing Case 1.

[0019] Figure 3 A schematic diagram of the composite process for implementing Case 1.

[0020] Figure 4 A schematic diagram of the multi-purpose embossing device for implementing Case 2.

[0021] Figure 5 A schematic diagram of the composite process for implementing Case 2.

[0022] Figure 6 A schematic diagram of the multi-purpose embossing device for implementing Case 3.

[0023] Figure 7 A schematic diagram of the composite process for implementing Case 3.

[0024] Figure 8 A schematic diagram of the multi-purpose embossing device for implementing Case 4.

[0025] Figure 9A schematic diagram of the composite process for implementing Case 4.

[0026] Figure 10 A schematic diagram of the multi-purpose embossing device for implementing Case 5.

[0027] Figure 11 A schematic diagram of the composite process for implementing Case 5.

[0028] Figure 12 A schematic diagram of the multi-purpose embossing device for implementing Case Six.

[0029] Figure 13 A schematic diagram of the composite process for implementing Case Six.

[0030] Figure 14 This is a schematic diagram of the background pattern E.

[0031] Figure 15 This is a schematic diagram of the layered pattern F.

[0032] Among them, 1-pre-embossing roller group, 11-pre-pressing back roller, 12-pre-embossing roller, 2-composite roller group, 21-composite back roller, 22-composite pressure roller, 23-composite adhesive roller, 1A, 2A, 3A, 4A-base paper, 1B, 2B, 3B, 4B-embossing paper, D-multi-layer paper web, E-background pattern, F-layered pattern. Detailed Implementation

[0033] To facilitate understanding of this utility model, a more complete description of it is provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0034] See appendix Figure 1-15 As shown in this embodiment, a multi-purpose embossing device suitable for tissue paper includes at least three independently arranged pre-embossing roller groups 1 and one composite roller group 2. For ease of understanding, the following can be used... Figure 1-9 The four sets of pre-pressing rollers shown constitute 1, and can also be used as follows: Figure 10-11The diagram shows three sets of pre-embossing rollers 1. Numbers 1A, 2A, 3A, and 4A correspond to one path of base paper, while numbers 1B, 2B, 3B, and 4B correspond to embossed paper after being embossed by the pre-embossing rollers 1. That is, each set of pre-embossing rollers 1 corresponds to one path of base paper, and can selectively emboss the corresponding base papers 1A, 2A, 3A, and 4A to form embossed paper 1B, 2B, 3B, and 4B with a background pattern E. Next, the composite roller set 2 is used to composite at least two paths of embossed paper 1B, 2B, 3B, and 4B from the aforementioned pre-embossing rollers 1, or to composite at least one path of the aforementioned embossed paper 1B, 2B, 3B, and 4B with at least one path of unembossed base paper 1A, 2A, 3A, and 4A.

[0035] Specifically, see Appendix Figure 1 As shown, in this embodiment, each group of pre-pressing rollers 1 consists of a pre-pressing roller 12 and a pre-pressing back roller 11 that fit closely together. The surface of the pre-pressing roller 12 is provided with raised textures that match the background pattern E. The pre-pressing roller 12 is made of hard metal, and the pre-pressing back roller 11 is made of soft rubber. Through the mutual pressing and cooperation of the pre-pressing roller 12 and the pre-pressing back roller 11, a series of base papers 1A, 2A, 3A, and 4A pass through the gap between the roller surface of the pre-pressing rubber roller and the pre-pressing roller 12. At this time, the raised textures on the surface of the pre-pressing rubber roller compress the base papers 1A, 2A, 3A, and 4A, causing the base papers 1A, 2A, 3A, and 4A to be pressed against the roller surface. The raised tips of the textured surface are locally thinned under concentrated pressure (forming micro-embossing dots). At the same time, the pre-embossing back roller 11 deforms due to elastic pressure, providing support for the base papers 1A, 2A, 3A, and 4A and preventing them from being punctured. Meanwhile, the non-raised part of the pre-embossing roller 12 contacts the elastic surface of the rubber roller, applying uniform basic pressure only to the base papers 1A, 2A, 3A, and 4A. The base papers 1A, 2A, 3A, and 4A maintain their original thickness (forming non-embossed flat areas). Finally, the surface of the base papers 1A, 2A, 3A, and 4A is embossed to form a background pattern E composed of several micro-embossing dots, resulting in embossed papers 1B, 2B, 3B, and 4B. Therefore, each set of pre-embossing rollers 1 is used to perform preliminary embossing on one line of base paper 1A, 2A, 3A, 4A to form embossed paper 1B, 2B, 3B, 4B with background pattern E. Based on this, according to actual product requirements, an appropriate number of lines of base paper 1A, 2A, 3A, 4A are selected for pre-embossing. One set of pre-embossing rollers 1 corresponds to one line of base paper 1A, 2A, 3A, 4A.

[0036] Furthermore, since the raised texture of the pre-embossing roller 12 has a fine structure, abnormal problems such as paper sticking to the roller surface may occur. Therefore, in this embodiment, the pre-embossing back roller 11 is located to the side of the pre-embossing roller 12 to form a vertically or obliquely arranged embossing channel, so that the corresponding base paper 1A, 2A, 3A, 4A passes through the embossing channel vertically or obliquely. That is: when the axes of the pre-embossing back roller 11 and the pre-embossing roller 12 are on the same horizontal plane to form a vertically arranged embossing channel, the corresponding base paper 1A, 2A, 3A, and 4A will pass vertically through the embossing channel; when the pre-embossing back roller 11 is located at an oblique side relative to the pre-embossing roller 12 to form an obliquely arranged embossing gap channel, the corresponding base paper 1A, 2A, 3A, and 4A will pass obliquely through the embossing channel. The above arrangement can avoid the weight of the roller body from causing additional stress to the embossing channel, thereby effectively reducing the friction between the base paper and the roller surface during the embossing process, avoiding problems such as paper sticking, wrinkling, paper jamming, or tearing, and further improving the embossing effect and stability.

[0037] In this embodiment, see Appendix Figure 1 As shown, the composite roller group 2 is used to composite at least two paths of embossed paper 1B, 2B, 3B, 4B, or to composite at least one path of embossed paper 1B, 2B, 3B, 4B with at least one path of un-pre-embossed base paper 1A, 2A, 3A, 4A. That is, the pre-embossed embossed papers 1B, 2B, 3B, 4B can be directly laminated by the composite roller group 2 to form a multi-layer paper web D. Specifically, the composite roller group 2 in this embodiment includes a composite pressure roller 22 (hard metal roller) and a composite back roller 21 (hard smooth roller) that are closely fitted together. The surface of the composite pressure roller 22 is partially formed with a raised composite boss. Thus, at least two paths of embossed paper 1B, 2B, 3B, 4B, or At least one path of embossed paper 1B, 2B, 3B, 4B and base paper 1A, 2A, 3A, 4A converges into the gap between the composite pressure roller 22 and the composite back roller 21. The composite bosses squeeze the stacked embossed paper 1B, 2B, 3B, 4B or base paper 1A, 2A, 3A, 4A, thereby locally thinning the paper under concentrated pressure at the protruding tips of the composite bosses (forming a layered pattern F). Simultaneously, the composite back roller 21 provides support for each path of embossed paper 1B, 2B, 3B, 4B or base paper 1A, 2A, 3A, 4A, preventing punctures and maintaining the original thickness. Finally, they are laminated together to form a multi-layered paper web D, and a layered pattern F is locally formed on the surface of the multi-layered paper web D. This layered pattern F can be formed as follows: Figure 14 and 15 The "Yunrou" lettering shown can be used by those skilled in the art to design layered patterns F as needed, without specific limitations here. Similarly, those skilled in the art can design the composite pressure roller 22 structure according to actual needs, as shown in the attached figure. Figure 1-4 The implementation example shown.

[0038] To facilitate understanding, the following explanations are provided using different implementation examples.

[0039] Implementation Case 1: See Appendix Figure 2 and 3 As shown, in this case, the base papers 2A and 3A need to form a background pattern E, while the base papers 1A and 4A are surface layers that do not require a background pattern E. Therefore, two sets of pre-embossing roller groups 1 and one set of composite roller groups 2 are selected. Specifically, the two sets of base papers 2A and 3A are mechanically nested and pre-embossed by the two sets of pre-embossing roller groups 1 to form embossed papers 2B and 3B with a background pattern E. Then, the two sets of pre-embossed embossed papers 2B and 3B are used as interlayers and sandwiched between the two sets of un-pre-embossed base papers 1A and 4A, so that the two sets of embossed papers 2B and 3B and the two sets of thin base papers 1A and 4A are stacked and merged into the composite roller group 2 and composite embossed to form a multi-layer paper web D (the multi-layer paper web D here is composed of "1A-2B-3B-4A" in the stacking order). Because the micro-embossed dots of the background pattern E on the surface of the pre-embossed 2B and 3B embossed papers are delicate and soft to the touch, the laminated paper products can avoid the background pattern of the interlayer showing through the surface layer. For consumers, there is no visual difference compared with traditional multi-layered paper products. In terms of touch, there is no unevenness and the overall characteristics are soft. At the same time, the paper products with the pre-embossed 2B and 3B embossed papers sandwiched in between are more fluffy and thicker than the composite paper products of traditional multi-layered paper products that are directly laminated.

[0040] Implementation Case 2: See Appendix Figure 4 and 5 As shown, in this case, the four base papers 1A, 2A, 3A, and 4A all need to be embossed to form embossed papers 1B, 2B, 3B, and 4B with a background pattern E. Therefore, four sets of pre-embossing roller groups 1 and one set of composite roller groups 2 are selected. Specifically, each base paper 1A, 2A, 3A, and 4A is mechanically nested and pre-embossed by the four sets of pre-embossing roller groups 1 to form embossed papers 1B, 2B, 3B, and 4B with a background pattern E. Then, the pre-embossed embossed papers 1B, 2B, 3B, and 4B are... Layer B is stacked into the composite roller group 2 and composite embossed to form a multi-layer paper web D (the multi-layer paper web D here is composed of "1B-2B-3B-4B" in the stacking order). Visually, the paper product after stacking and lamination can see the background pattern EE on both the front and back, presenting a delicate visual effect. In addition, because the micro-embossing dots of the background pattern E are delicate and soft to the touch, it presents a soft overall characteristic. Secondly, the overall thickness of the paper product after stacking and lamination is more fluffy and thicker than that of the first implementation case.

[0041] In summary, the above implementation case one or implementation case two uses four-way thin base paper 1A, 2A, 3A, 4A as an example. However, in actual production, those skilled in the art can appropriately reduce the number of thin base paper to three, or increase it to five or more as needed.

[0042] In this embodiment, the composite roller group 2 further includes a composite adhesive roller 23 that closely engages with the composite pressure roller 22. At least one path of base paper 1A, 2A, 3A, 4A or embossed paper 1B, 2B, 3B, 4B is embossed between the composite pressure roller 22 and the composite adhesive roller 23, so that the base paper 1A, 2A, 3A, 4A or embossed paper 1B, 2B, 3B, 4B partially form a layered pattern F (as shown in the attached diagram). Figure 3 and attached Figure 5 The layered pattern F shown is then laminated with other base papers 1A, 2A, 3A, 4A or embossed papers 1B, 2B, 3B, 4B between the composite back roll 21 and the composite pressure roll 22.

[0043] Furthermore, the surface of the composite pressure roller 22 is provided with composite bosses that can respectively cooperate with the composite rubber roller 23 and the composite back roller 21. The composite bosses cooperate with the composite rubber roller 23 to emboss at least one path of embossed paper 1B, 2B, 3B, and 4B, so that the composite bosses form a layered pattern F. Subsequently, it is laminated with other paths of base paper 1A, 2A, 3A, and 4A or embossed paper 1B, 2B, 3B, and 4B between the composite bosses of the composite back roller 21 and the composite pressure roller 22. To facilitate understanding of the composite pressure roller 22 with composite bosses, the following explanation is provided in conjunction with specific implementation example four.

[0044] Implementation Case 3: See Appendix Figure 6 and 7As shown, in this case, the three base papers 1A, 2A, and 3A all need to be embossed to form embossed papers 1B, 2B, and 3B with a background pattern E. Three sets of pre-embossing rollers 1 and one set of composite rollers 2 consisting of a composite pressure roller 22, a composite back roller 21, and a composite rubber roller 23 are selected. The three base papers 1A, 2A, and 3A are mechanically nested and pre-embossed by the three sets of pre-embossing rollers 1 to form embossed papers 1B, 2B, and 3B with a background pattern E. One of the embossed papers, 1B, is then transferred to the gap between the composite pressure roller 22 and the composite rubber roller 23 for embossing processing. The composite protrusion and composite roller 23 work together to emboss the embossed paper 1B with the background pattern E, and further emboss the local area to form a layered pattern F. Then, the three embossed papers 1B, 2B, and 3B are stacked together and merged into the gap between the composite pressure roller 22 and the composite back roller 21 to form a multi-layer paper web D (the multi-layer paper web D here is composed of "1B-2B-3B" in the stacking order). In this way, the pre-embossing and composite processing of the three base papers 1A, 2A, and 3A are realized. The background pattern E and the layered pattern F are clear and complete, and the composite does not delaminate.

[0045] Implementation Case 4: See Appendix Figure 8 and 9 As shown, in this case, one of the base papers 2A needs to be embossed to form an embossed paper 2B with a background pattern E. The other two base papers 1A and 3A do not need to form a background pattern E. Therefore, a set of pre-embossing roller group 1 and a set of composite roller group 2 consisting of composite pressure roller 22, composite back roller 21 and composite rubber roller 23 are selected. One of the base papers 2A is mechanically nested and pre-embossed by a set of pre-embossing roller group 1 to form an embossed paper 2B with a background pattern E. At the same time, one of the base papers 1A is directly transferred to the gap between the roller surface of composite pressure roller 22 and composite rubber roller 23 for embossing treatment (at this time, the composite bosses In conjunction with the composite roller 23, embossing is performed on the base paper 1A to form a layered pattern F. Subsequently, the base paper 1A with the layered pattern F, the embossed paper 2B with the background pattern E, and the untreated base paper 3A are layered together and merged into the gap between the composite pressure roller 22 and the composite back roller 21 to form a multi-layered paper web D (the multi-layered paper web D here is composed of "1A-2B-3A" in the stacking order). In this way, the pre-embossing and composite processing of the three base papers 1A, 2A, and 3A are achieved. The background pattern E and the layered pattern F are clear and complete, and the composite does not delaminate.

[0046] Implementation Case 5: See Appendix Figure 10 and 11As shown, in this case, the two raw paper lines 1A and 3A are defined as the surface layers, and both need to be embossed to form embossed paper 1B and 3B with the background pattern E. The other raw paper line 2A is used as the interlayer and does not need to form a background pattern. Therefore, two sets of pre-embossing roller groups 1 and one set of composite roller group 2 consisting of composite pressure roller 22 and composite back roller 21 are selected. The two raw paper lines 1A and 3A are respectively mechanically nested and pre-embossed by the two sets of pre-embossing roller groups 1 to form embossed paper 1B and 3B with the background pattern E. Subsequently, the processing... After processing, the embossed papers 1B and 3B are transferred together with another source paper 2A and fed into the gap between the composite pressure roller 22 and the composite back roller 21 for composite embossing to form a multi-layer paper web D (the multi-layer paper web D here is composed of "1B-2A-3B" in the stacking order, and the multi-layer paper web D has a stacked pattern F in some parts). In this way, the pre-embossing and composite processing of the three source papers 1A, 2A and 3A result in clear and complete background pattern E and stacked pattern F, and the composite does not delaminate.

[0047] Implementation Case Six: See Appendix Figure 12 and 13 As shown, in this case, the two base papers 1A and 4A are defined as the surface layer, and the base papers 2A and 3A are defined as the interlayer. The base papers 1A and 3A need to be embossed to form embossed paper 1B and 3B with background pattern E, while the other base papers 2A and 4A do not need to form background pattern E. Therefore, two sets of pre-embossing roller groups 1 and one set of composite roller group 2 consisting of composite pressure roller 22 and composite back roller 21 are selected. The two sets of base paper 1A and 3A are mechanically nested and pre-embossed by the two sets of pre-embossing roller groups 1 to form embossed paper 1B and 3B with background pattern E. Subsequently, the processed embossed paper 1B and 3B, together with the remaining base paper 2A and 4A, are transferred into the roller surface gap between composite pressure roller 22 and composite back roller 21 for composite embossing to form multi-layer paper web D (here, multi-layer paper web D is composed of "1B-2A-3B-4A" in the stacking order, and multi-layer paper web D has a stacked pattern F in some parts). In this way, one side of multi-layer paper web D is a flat surface and the other side is an embossed surface. The background pattern E and the stacked pattern F are clear and complete, and the composite does not delaminate.

[0048] In summary, this embodiment can dynamically select the appropriate number of pre-embossing roller groups 1 and suitable composite roller groups 2 according to different production needs. Through modular roller group design and multi-process collaboration, it solves the technical bottleneck of embossing and laminating low basis weight base paper 1A, 2A, 3A, and 4A. It is suitable for the efficient production of various household paper products such as facial tissues and kitchen paper, and has significant economic and technical value.

[0049] In this embodiment, because the paper material is prone to static electricity buildup due to friction during transfer and embossing, as well as the influence of the drying environment, which affects the stability of the composite process, therefore, the attached... Figure 4Taking the illustrated implementation as an example, an electrostatic elimination device is installed between the pre-embossing roller group and the composite roller group. This device neutralizes the static electricity on the surfaces of embossed paper 1B, 2B, 3B, and 4B, ensuring smooth and precise transport and alignment of subsequent embossed paper and / or base paper at the composite roller group. This prevents paper web misalignment or wrinkling caused by electrostatic adsorption, thereby guaranteeing the interlayer lamination effect of the multi-layer paper web D. Specifically, the electrostatic elimination device in this implementation is a conductive crossbar (made of a metal or non-metal material with good conductivity, such as copper, carbon fiber, etc.) that spans the transport path of embossed paper 1B, 2B, 3B, and 4B. The conductive crossbar can be grounded via a wire to release accumulated charge in a timely manner, effectively suppressing electrostatic interference. The conductive crossbars can be connected to the embossed paper strips 1B, 2B, 3B, and 4B in a contact configuration. The conductive crossbars are directly and lightly pressed onto the paper surface, quickly conducting static electricity through physical contact. Alternatively, a non-contact ionizer can be used to eliminate static electricity. The positive and negative ions generated by the ionizer neutralize the static charge on the paper surface, achieving non-contact static elimination and avoiding scratches or tension fluctuations that might occur with contact conductive crossbars. Both methods effectively eliminate static electricity carried by the paper web during high-speed operation.

[0050] Furthermore, in conjunction with the appendix Figure 14 and 15 The embossed papers 1B, 2B, 3B, and 4B shown have background pattern E and are attached. Figure 11 The embossed papers 1B, 2B, 3B, and 4B, shown with background pattern E and layered pattern F, further illustrate the raised texture described above. In this embodiment, the raised texture consists of several embossing protrusions (the height of each embossing protrusion can be uniform or have varying heights; those skilled in the art can select an appropriate roller surface structure as needed, as long as the embossing protrusions act on the base paper to form the background pattern E). The layout of the embossing protrusions matches the background pattern E; therefore, the embossing protrusions satisfy the following characteristics: • The total area of ​​all embossed protrusions within a unit square decimeter accounts for 13-20% of the total area. • The area of ​​each embossed boss is 0.015-0.23 mm². 2 .

[0051] To facilitate understanding of the above features, further explanations are provided below. By elaborating on the parameter settings of "point area" and "total area ratio" of the embossing protrusion, the core objective of the embossing protrusion is to solve the pain points of embossing low-grammage thin base paper (8-20g / m²): poor forming effect (easy to puncture or blurry indentation), insufficient stiffness of the embossing structure (poor support leading to texture deformation and collapse), etc.

[0052] In this embodiment, the percentage (13-20%) of the total area of ​​embossing protrusions per unit square decimeter is explained as follows: First, 'unit square decimeter' refers to each 1dm² area (1dm² = 100cm²). Second, within each square decimeter area, the sum of the areas of all embossing protrusions accounts for 13-20% of the total area of ​​that square decimeter area. By setting the area percentage (13-20%) range to match the fiber distribution of low-basis-weight thin base paper 1A, 2A, 3A, and 4A—the pressure (pressure / area) at the tip of the embossing protrusion is 3-5MPa (just enough to compress the fibers without piercing them), while the contact area of ​​the waist of the embossing protrusion (accounting for 60-70% of a single protrusion) fully adheres to the rubber roller (eliminating gaps), ensuring that the embossed dots are "both clear and complete."

[0053] Secondly, by using a point area of ​​0.015-0.23mm for each embossed boss. 2 Based on this method, the number of embossing protrusions is estimated to be approximately 5,652-133,333 per dm² (i.e., about 56-1333 per cm²). Because low-grammage thin base paper (1A, 2A, 3A, 4A) has low fiber content (8-20 g / m²) and a loose structure, it is easy for excessive pressure on a single protrusion during embossing to cause puncture, or insufficient pressure to cause blurred indentations. Therefore, the area of ​​the protrusions set in this embodiment is 0.015-0.23 mm². 2 Define the lower limit of the number of embossed protrusions per unit area (56 protrusions / cm²) and the upper limit of the number of embossed protrusions per unit area (1333 protrusions / cm²).

[0054] Specifically, when the area of ​​each embossed boss is 0.23mm... 2 If the number of embossing protrusions per unit area is less than 56 per cm², then the distribution of these protrusions is “sparse large dots” (i.e., large area of ​​each dot and relatively sparse distribution). If the number of embossing protrusions per unit area is less than 56 per cm² (e.g., 50 per cm²), then each embossing protrusion will have to bear greater pressure (the total pressure is distributed among 50 points → the pressure on each point increases). Low-grammage thin base paper 1A, 2A, 3A, and 4A are easily punctured by the tips of the embossing protrusions because of their low fiber strength (breaking strength is only 20-30N).

[0055] Specifically, when the area of ​​each embossed boss is 0.015mm² 2If the maximum number of embossed protrusions per unit area is 1333 per cm², then the paper exhibits "sparse large dots" (i.e., small area of ​​each dot and relatively dense distribution). If the number of embossed protrusions per unit area is greater than 1333 per cm² (e.g., 1500 per cm²), the embossed protrusions are too densely distributed, the fibers between the embossed protrusions are excessively compressed, the paper's absorbency (e.g., the water absorption speed of tissue paper) decreases by 25%-30% (because the pores between fibers are closed by the embossed dots), and the softness decreases (EMTEC value < 70), which cannot meet the skin-friendly requirements of sanitary paper and cannot form clear and complete embossed protrusions.

[0056] Therefore, the area of ​​the embossed boss is 0.015-0.23mm. 2 The combined effect of the area ratio (13-20%) ensures that the pressure of each embossing protrusion on the low-grammage thin base paper 1A, 2A, 3A, and 4A is dispersed (avoiding puncture) and concentrated (ensuring indentation), ultimately achieving the forming effect of "no puncture, no blurring, and uniform full coverage of embossing points".

[0057] In this embodiment, for regular and orderly pattern designs, the embossed bosses also satisfy the following characteristics: (3) The distance a between any two adjacent embossed protrusions in the same row is 0.2-0.95 mm; (4) The row spacing b between any two adjacent rows of embossed protrusions is 0.2-0.95mm.

[0058] Furthermore, the direction of the aforementioned dot spacing a is parallel to the roller axis, and the direction of the row spacing b is parallel to the paper feeding direction.

[0059] Specifically, the dot spacing 'a' (0.2-0.95mm) is explained as follows: It refers to the lateral distance between any two adjacent embossing protrusions in the same row. Since low-basis-weight thin base paper is only 0.07-0.13mm thick (approximately 1 / 3 the thickness of ordinary A4 paper, with a loose fiber structure, poor rigidity, and weak tensile strength), its embossing quality highly depends on the stretching and shaping effect of the embossing protrusions on the fibers. The upper and lower limits (0.2-0.95mm) of the dot spacing 'a' (lateral distance between adjacent embossing points) are essentially set to optimize the degree of fiber stretching and stress balance during the embossing process by controlling the distribution density of the embossing protrusions, thus avoiding insufficient stretching (leading to blurred indentations) or excessive stretching (leading to fiber breakage) that affects product performance. Therefore, based on the implementation, the lower limit (a < 0.3mm) and upper limit (0.95mm) of the dot spacing 'a' are set. If the dot spacing a < 0.2mm (e.g., 0.15mm), the waist spacing between adjacent embossing bosses on the pre-embossing roller is too small (at this time, the waist width of the boss is 0.05-0.1mm). This causes the pre-pressing roller to deform under pressure and fail to completely fill the gap between the bosses, forming a "virtual gap". The virtual gap results in insufficient effective pressing depth of the embossing boss tip into the thin base paper. During the embossing process, the fibers need sufficient pressing depth to achieve plastic deformation of transverse stretching and longitudinal compression. When the pressing depth is insufficient, the tensile stress on the fibers does not reach the threshold for their orientation and cannot be fully unfolded and tightly filled into the embossed area. Ultimately, the fibers in the embossed area become loose due to insufficient stretching, failing to form a clear embossed outline, resulting in a blurred embossed area. If the dot spacing a > 0.95 mm (e.g., 1.0 mm), the waist distance between adjacent embossing bosses on the pre-embossing roller is too large. Although the pre-embossing roller can completely fill the gap, the bosses are sparsely distributed (only 10 points per 10 mm row), resulting in a lack of effective support points for the fibers in the unpressed area between the two bosses. During the embossing process, the thin base paper is subjected to continuous traction force as the roller rotates, and the fibers in the unpressed area are stretched simultaneously in the longitudinal direction (roller rotation direction) and the transverse direction (dot spacing direction). Due to the low support point density (1 support point / mm at a dot spacing of 1.0 mm, lower than 1.05 points / mm at 0.95 mm), the fiber tensile stress cannot be dispersed by the constraint of adjacent bosses. The local fiber stretching exceeds its elastic limit, ultimately causing the tensile stress to exceed the fiber's breaking strength, resulting in irreversible fiber breakage, manifested as local paper damage, holes, or edge tearing.

[0060] In summary, by setting the lower limit of the dot spacing a to 0.2mm and the upper limit to 0.95mm, the "appropriateness" of fiber stretching can be achieved. The core of this setting is to balance the stretching degree of low basis weight thin paper fibers by adjusting the distribution density of the embossing protrusions—ensuring that the fibers are fully stretched to shape the indentation, while avoiding excessive stretching that could lead to breakage, ultimately achieving an embossing effect with clear indentations and a complete structure.

[0061] Specifically, regarding the row spacing b (0.2-0.95mm): In low-basis-weight thin base paper (thickness 0.07-0.13mm), the longitudinal fibers exhibit a "closer arrangement" characteristic due to the papermaking process, resulting in significantly weaker tensile properties (longitudinal tensile strength 1.0-1.5kN / m) compared to the transverse fibers. The upper and lower limits (0.2-0.95mm) of the row spacing b (the distance between two adjacent longitudinal embossing points) are essentially set to match the tensile load-bearing capacity of the longitudinal fibers by adjusting the distribution density of the longitudinal embossing points—avoiding both localized overload caused by fiber stretching (manifested as uneven indentation depth) and excessive stretching due to insufficient tensile support (manifested as row misalignment or fiber breakage), ultimately achieving "uniform shaping" and "structural stability" of the longitudinal fibers. Therefore, when the row spacing b is less than 0.3mm (e.g., 0.28mm), the longitudinal embossing protrusions on the pre-embossing roller are too densely arranged (more than 33 points within 10mm longitudinally), and the stretching effect of adjacent rows of embossing protrusions on the fibers overlaps (the longitudinal stretching effect radius is approximately 0.15-0.2mm). At this time, the longitudinal fibers are simultaneously subjected to the tensile stress of the upper and lower rows of embossing protrusions, forming a "superimposed stretching effect." Because the longitudinal fibers of low basis weight paper are densely arranged but have poor tensile strength, the superimposed stretching stress will cause local fiber segments (fibers between adjacent embossing points) to be subjected to tensile forces exceeding their elastic limits. Specifically, this manifests as differences in the amount of stretching in different areas of the longitudinal fibers (including overstretching and understretching), ultimately resulting in significant deviations in the embossing depth and an uneven background pattern. When the row spacing b is greater than 0.95mm (e.g., 1.3mm), the spacing between the longitudinal embossing bosses on the pre-embossing roller is too large (only 7-8 points within 10mm longitudinally). This causes the longitudinal fibers to form "long fiber free segments" (the length of fiber segments not fixed by embossing points is >0.5mm) between adjacent rows of embossing bosses. Due to the weak tensile strength of the longitudinal fibers in low-grammage paper, they are subjected to continuous longitudinal traction force as the roller rotates during the embossing process. At this time, the "long fiber free segments" are subjected to unrestrained excessive stretching due to the lack of mechanical fixation by the embossing bosses (support point density <0.8 points / mm), resulting in fiber breakage and fiber displacement. Specifically, this manifests as the offset of the embossing point position (row and column misalignment), accompanied by local fiber breakage, ultimately affecting the regularity of the background pattern.

[0062] In summary, by setting the lower limit of row spacing b to 0.3mm and the upper limit to 0.95mm, the stretching state of the longitudinal fibers can be precisely controlled. The essence of this setting is to adjust the distribution density of the longitudinal embossing points to adapt to the characteristics of the longitudinal fibers of low-grammage thin base paper, which are "closely arranged and have weak tensile strength". This avoids "uneven superimposed stretching" (inconsistent depth) caused by too small a spacing, and also prevents "insufficient support and excessive stretching" (row and column misalignment / breakage) caused by too large a spacing. Ultimately, it achieves uniform shaping and structural stability of the longitudinal fibers, ensuring the clarity and regularity of the embossing pattern.

[0063] In summary, the parameter settings for embossing protrusions (dot spacing a: 0.2-0.95mm, row spacing b: 0.2-0.95mm, unit quantity 65-300 pieces / cm², area ratio per square decimeter 13-20%) are precisely optimized for the embossing characteristics of low-grammage paper materials. By setting the ranges for dot spacing a and row spacing b, the core is to precisely control the tensile strength of the fibers by matching the "low rigidity and weak tensile strength" of the thin base paper. The lower limit of 0.3mm avoids "insufficient stretching" (dot spacing) or "stretch overlap" (row spacing) caused by overly dense protrusions, ensuring sufficient fiber shaping. The upper limit of 0.95mm avoids "excessive stretching and breakage" (dot spacing) or "excessive stretch displacement" (row spacing) caused by overly sparse protrusions, ensuring fiber structural stability. Ultimately, this achieves a high-quality embossing effect with clear indentations, regular patterns, and no breaks / damage. By synergistically adjusting the number and area ratio of embossed protrusions within a unit square decimeter area, the contradiction between "concentrated embossing pressure" and "fragility of low-grammage paper" is balanced, ultimately achieving a high-density texture effect with "clear forming and uniform pattern".

[0064] In this embodiment, each embossing protrusion is a circular, elliptical, rectangular, rhomboid, or polygonal structure with a planar dimension of 0.2×0.5-0.5×0.8mm (length×width) and a depth of 0.3-0.9mm (preferably 0.5mm), ensuring that the embossing point has sufficient mechanical strength while avoiding puncturing the thin base paper.

[0065] In summary, in any of the above implementation examples, the thin base paper 1A, 2A, 3A, and 4A can be composed of a single layer, two layers, or more layers of paper. Those skilled in the art can appropriately select the number of thin base paper layers based on the actual product or papermaking process. As long as the basis weight meets the basic condition of 8-20 g / m² for low-basis-weight paper, the synergistic forming of pre-embossing and composite embossing can be achieved, ensuring that the background pattern E and the layered pattern F are distinct, three-dimensional, and soft to the touch in the multi-layer paper web D. Secondly, the embossing protrusions between the pre-embossing rollers 21 of different embossing roller groups 1 can be designed with different sizes, resulting in differences in the size of the protrusions on the background pattern E of the embossed base paper formed by each embossing roller group 1. In particular, the protrusion size of the background pattern E of the embossed base paper used as the interlayer is slightly larger than that of the surface embossed base paper. This effectively improves the support and bulkiness of the composite multi-layer paper web D without affecting the surface flatness and tactile comfort of the multi-layer paper web D.

[0066] The embodiments described above are merely preferred embodiments of this utility model and are not intended to limit the utility model in any way. Any modifications or alterations made by those skilled in the art to the technical solution of this utility model without departing from its scope are equivalent embodiments of this utility model. Therefore, all equivalent changes made based on the concept of this utility model without departing from its scope should be covered within the protection scope of this utility model.

Claims

1. A multi-purpose embossing device suitable for household paper, characterized in that: It includes at least three independently set pre-embossing roller groups (1) and one composite roller group (2). Each pre-embossing roller group (1) corresponds to one source paper (1A, 2A, 3A, 4A) and can emboss the corresponding source paper (1A, 2A, 3A, 4A) to form embossed paper (1B, 2B, 3B, 4B) with a background pattern (E). The composite roller group (2) is used to composite at least two sources of embossed paper (1B, 2B, 3B, 4B) from the aforementioned at least two sets of pre-embossing roller groups (1), or to composite at least one source of the aforementioned embossed paper (1B, 2B, 3B, 4B). 1B, 2B, 3B, 4B) are compounded with at least one unembossed base paper (1A, 2A, 3A, 4A); each group of pre-embossing rollers (1) includes a pre-embossing back roller (11) and a pre-embossing roller (12) that are closely fitted together. The surface of the pre-embossing roller (12) is provided with raised textures that match the background pattern (E). The pre-embossing back roller (11) is located to the side of the pre-embossing roller (12) to form a vertically or obliquely arranged embossing channel, so that the corresponding base paper (1A, 2A, 3A, 4A) passes through the embossing channel vertically or obliquely.

2. The multi-purpose embossing device for household paper as described in claim 1, characterized in that: The composite roller group (2) includes a composite pressure roller (22) and a composite back roller (21) that are closely fitted together.

3. The multi-purpose embossing device for household paper as described in claim 2, characterized in that: The composite roller group (2) also includes a composite rubber roller (23) that closely cooperates with the composite pressure roller (22). At least one type of base paper (1A, 2A, 3A, 4A) or embossed paper (1B, 2B, 3B, 4B) is embossed between the composite pressure roller (22) and the composite rubber roller (23) to form a layered pattern (F) in a localized area of ​​the base paper (1A, 2A, 3A, 4A) or embossed paper (1B, 2B, 3B, 4B). Then, it is laminated with other types of base paper (1A, 2A, 3A, 4A) or embossed paper (1B, 2B, 3B, 4B) between the composite back roller (21) and the composite pressure roller (22).

4. The multi-purpose embossing device for household paper as described in claim 3, characterized in that: The surface of the composite pressure roller (22) is provided with composite bosses that can cooperate with the composite rubber roller (23) and the composite back roller (21) respectively. The composite bosses cooperate with the composite rubber roller (23) to emboss at least one path of base paper (1A, 2A, 3A, 4A) or at least one path of embossed paper (1B, 2B, 3B, 4B) to form a layered pattern (F) in a localized area of ​​the base paper (1A, 2A, 3A, 4A) or embossed paper (1B, 2B, 3B, 4B). Then, the base paper (1A, 2A, 3A, 4A) or embossed paper (1B, 2B, 3B, 4B) of the composite pressure roller (22) is laminated with the composite bosses of the composite pressure roller (22) and the composite back roller (21).

5. The multi-purpose embossing device for household paper as described in claim 1, characterized in that: The raised texture is composed of several embossed protrusions, and the embossed protrusions satisfy the following characteristics: • The total area of ​​all embossed protrusions within a unit square decimeter accounts for 13-20% of the total area. • The area of ​​each embossed boss is 0.015-0.23 mm². 2 .

6. The multi-purpose embossing device for household paper as described in claim 1, characterized in that: An electrostatic elimination device (30) for electrostatic treatment of the surface of the pre-embossed paper (1B, 2B, 3B, 4B) after pre-embossing is provided between the pre-embossed roller group (1) and the composite roller group (2).

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