Fine line composite embossing device

Abstract

The invention discloses a fine grain composite embossing device which is characterized in that multiple layers of raw paper are embossed and composited through an embossing roller and a composite net roller which are in rolling fit with each other, the performance bottleneck of an existing embossing process is broken through through the collaborative design of small-size main flower points, high-density composite points and accurate contact proportion, and particularly through the innovative design of 25%-60% of contact area proportion, the fine grain composite embossing device has the advantages that the fine grain composite embossing device is simple in structure and convenient to use. And the balance of flexibility, firmness and visual effect of the product is realized. The process is suitable for low-cost raw paper, is high in process stability, and has remarkable industrial application value and market competitiveness.

Description

Technical Field

[0001] This invention relates to the technical field of tissue paper processing, and in particular to a fine-textured composite embossing device. Background Technology

[0002] In the field of paper embossing, embossing with convex rollers and embossing with convex dot rollers are currently the mainstream composite processes. However, both have significant drawbacks in practical applications, making it difficult to meet the requirements of product feel, pattern effect and structural stability.

[0003] For embossing with a convex roller, the core issue lies in the "full contact" (i.e., the main pattern point is 100% in contact with the roller surface) of the composite surface. When the main pattern uses large-area grids of single points, segmented lines, or continuous lines, the composite area is prone to hardening due to concentrated pressure and lack of stress release space. If the main pattern is based on long lines (segmented or continuous), the elongation of the paper caused by compression during the embossing process cannot be effectively released, ultimately resulting in obvious "stiffening" defects, which seriously affect the product's appearance and user experience.

[0004] While the convex dot roll embossing process attempts to disperse pressure through dot distribution, existing dot designs suffer from multiple parameter imbalances: On the one hand, composite dots are often arranged in a spiral or regular array. During long-term roll embossing, the contact position between the composite dots and the main pattern dots is fixed and the pressure is concentrated, causing repeated squeezing on the surface of the main pattern dots to form toothed grooves. This not only damages the integrity of the main pattern dots, leading to pattern deformation and blurring, but also exacerbates roller wear and shortens service life. On the other hand, if the gap between composite dots is too large, the main pattern is prone to defects and incompleteness, resulting in poor visual effects. Furthermore, the total area of ​​composite dots is insufficient, leading to poor lamination and easy perforation. If the gap between composite dots is infinitely increased to avoid stemming, it will further exacerbate the problems of pattern defects and poor lamination. When the area of ​​composite dots is less than 10%, the wear resistance and service life of the roller will decrease significantly.

[0005] In addition, existing embossing processes have poor adaptability to base paper, especially for short fiber low grammage paper (usually thin base paper with a specified weight of 8-20 g / m² and a thickness of only 0.07-0.13 mm). The above defects will be further amplified, making it difficult to use such base paper in the production of mid-to-high-end embossed products. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a fine-texture composite embossing device. By precisely designing the structural parameters of the main embossing point and the composite point and their contact relationship, it fundamentally solves the core problems in the existing process such as "wear of the tooth groove of the main embossing point, hardening and stiffening of the product, incomplete pattern, and weak lamination". It achieves the technical effect of "soft feel, full and clear pattern, strong lamination, and anti-perforation" of embossed products, while extending the service life of the roller.

[0007] To achieve the above objectives, the present invention provides a fine-textured composite embossing device that uses embossing rollers and composite wire rollers that cooperate with each other to emboss and composite multiple layers of base paper. The embossing roller surface is provided with a main floral pattern composed of several main floral dots arranged at intervals, wherein the dotted structure of the main floral pattern satisfies the following characteristics: • The surface dimension D1 of each main flower dot is 0.15-0.9 mm²; • The area of ​​all main floral patterns on the surface of the embossing roller accounts for 1.5%-10%; The surface of the composite roller is provided with a plurality of composite points, wherein the composite points satisfy the following characteristics: • The surface dimension D2 of each composite point is 0.01-0.05 mm²; • The area of ​​all composite points on the surface of the composite roller accounts for 25%-60%; During embossing, the area of ​​the embossed region between a single main flower point and several composite points accounts for 25%-60%.

[0008] Furthermore, the gap L1 between any two adjacent main flower points is 0.3-1mm.

[0009] Furthermore, the embossing height H1 of the main flower point is 0.3-0.65mm.

[0010] Furthermore, the surface size D1 of the main floral dots is 0.3-0.6 mm², and the area ratio of all main floral dots on the surface of the embossing roller is 3%-7%.

[0011] Furthermore, the gap L2 between any two adjacent composite points is 0.04-0.15 mm.

[0012] Furthermore, the embossing height H2 of the composite point is 0.06-0.12mm.

[0013] Furthermore, the shape of the main flower point is circular, square, rhomboid, or irregular polygon.

[0014] Furthermore, the composite points on the surface of the composite roller are arranged at intervals. The characteristics of the interval arrangement are as follows: a "layered array unit" is used as the basic arrangement unit, and several layers of the layered array unit are distributed on the surface of the composite roller. The relative positional relationship between two adjacent layers of the layered array unit is any one of tangency, partial overlap, or interval arrangement. A single layered array unit is composed of several layers of nested sub-units. Each layer of sub-units is distributed at intervals along the radial direction of the layered array unit. Each layer of sub-units is formed by several composite points arranged regularly along the contour trajectory of the sub-unit.

[0015] Furthermore, each layer of sub-units can be arranged coaxially or non-coaxially; the shape of each layer of sub-units is an annulus, triangle, ellipse or other closed contour.

[0016] Furthermore, the surface of the composite roller, except for the area covered by the layered array unit, is fully covered with several composite points, and the parameter characteristics of the composite points in this area are consistent with the parameter characteristics of the composite points in the layered array unit.

[0017] Furthermore, the composite points on the surface of the composite roller are arranged in a disordered distributed manner. The disordered distributed arrangement is characterized by the fact that the composite points have no fixed unit boundaries on the surface of the composite roller and are randomly distributed without any rules. Moreover, the surface size, adjacent gap, and embossing height of each composite point fluctuate independently and randomly within the range of the corresponding parameter characteristics.

[0018] The present invention adopts the above-mentioned solution, and its beneficial effects are as follows: 1) Comprehensive improvement in product performance: The embossed product has a soft feel, the main pattern is full and clear, the lamination points are firm, the main pattern points are wear-resistant, and it is not easy to perforate; 2) Enhanced process stability: By clearly defining the size, density and contact ratio of the main pattern points and composite points, and with precise control of process parameters such as roller speed and pressure, the vibration of the two rollers is small during the embossing process, the impact of the pattern point operation is small, and the product qualification rate is high; 3) Extended roller life: The non-full contact design of the main pattern points and composite points reduces roller surface wear, and the service life of the embossing roller and composite screen roller is extended by more than 60% compared with the existing technology. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a fine-textured composite embossing device.

[0020] Figure 2 A magnified view of the main flower point and the composite point.

[0021] Figure 3 A schematic diagram comparing the parametric characteristics of the main flower point and the composite point.

[0022] Figure 4 This is a schematic diagram showing the unfolded surface of the composite screen roller.

[0023] Figure 5 This is a partially enlarged schematic diagram of a single layered array cell.

[0024] Figure 6 This is a schematic diagram showing the tangential arrangement of two adjacent layered array units.

[0025] Figure 7 This is a schematic diagram showing the local overlapping arrangement of two adjacent layered array units.

[0026] Figure 8This is a schematic diagram showing the relative relationship between two adjacent hierarchical array units, arranged at intervals.

[0027] Figures 9 to 11 This is a schematic diagram of a layered array cell with different closed contour forms.

[0028] Among them, 1-embossing roller, 2-composite mesh roller, 11-main flower point, 21-composite point, A0-layer array unit. Detailed Implementation

[0029] To facilitate understanding of the present invention, a more complete description is given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0030] See appendix Figure 1-2 As shown, in this embodiment, a fine-textured composite embossing device uses an embossing roller 1 and a composite screen roller 2 that cooperate with each other to emboss and composite multiple layers of base paper. That is, multiple layers of base paper (at least two layers of base paper stacked together) pass through the gap between the roller surfaces of the embossing roller 1 and the composite screen roller 2, and the multiple layers of base paper are embossed and composited together by means of the cooperation of the two rollers to form a textured pattern on the surface.

[0031] In this embodiment, the surface of the embossing roller 1 is provided with a main floral pattern composed of a plurality of main floral dots 11 arranged at intervals (the main floral pattern here can be set according to the actual product requirements), wherein the dotted structure of the main floral pattern satisfies the following characteristics: Feature 1: The surface size D1 of each main flower dot 11 is 0.15-0.9mm². Its special feature is that it breaks through the design inertia of the existing technology that "the surface size of the main flower dot 11 is too large" (the surface size of the main flower dot 11 in the existing technology is mostly ≥1.0mm²). By setting this surface size D1 range, the key is to balance "pattern clarity" and "softness of hand feel" - if the surface size D1 of the main flower dot 11 is >0.9mm², even if the contact area ratio is controlled, the absolute contact area of ​​a single main flower dot 11 is still too large, which can easily lead to local hardening; if the surface size D1 of the main flower dot 11 is <0.15mm², the main flower dot 11 is prone to insufficient engraving precision and blurry pattern due to its small size.

[0032] Feature 2: The area ratio of all main floral dots 11 on the surface of embossing roller 1 is 1.5%-10%. Its special feature is that it abandons the misconception of "high ratio for pattern integrity" in the existing technology. This ratio range is balanced between visual effect and process stability through "dot density control" - when the ratio is >10%, the spacing of the main floral dots 11 is too close, and continuous hard areas are easily formed after lamination; when the ratio is <1.5%, the sparse main floral dots 11 lead to pattern defects, and the uneven force on embossing roller 1 is prone to vibration.

[0033] Feature 3: The gap L1 between any two adjacent main floral dots 11 is 0.3-1mm. Its special characteristic lies in forming an optimal gap ratio of "1:0.5-1:6.7" with the surface dimension D1 of the main floral dot 11. This gap L1 is the core of the "stress release channel"—if the gap L1 < 0.3mm, the base paper does not have enough space to release the compression elongation between the main floral dots 11, easily leading to hidden stitching; if the gap L1 > 1mm, the excessive spacing between the main floral dots 11 results in pattern dispersion and poor visual continuity. For example, when the surface dimension D1 of the main floral dot 11 is 0.4mm² and the gap L1 is 0.5mm, the elongation stress release rate reaches 90%, with no stitching phenomenon.

[0034] Feature 4: The embossing height H1 of the main floral dot 11 is 0.3-0.65mm, which is unique in that it adapts to the fiber strength characteristics of short-fiber base paper. Different base paper thicknesses correspond to different embossing heights H1 for the main floral dot 11. That is, for thin base paper (corresponding to a thickness of 0.15-0.3mm), the embossing height H1 can be 0.3-0.45mm, while for thick base paper (corresponding to a thickness of 0.3-0.7mm), the embossing height H1 can be 0.46-0.65mm. When the embossing height H1 is too high, chipping is likely to occur, resulting in high maintenance costs. When the embossing height H1 is too low, the floral dot is not durable and has a short service life. Ultimately, this leads to paper quality problems such as poor three-dimensionality of the pattern, penetration of the paper material, and rough edges.

[0035] The preferred range of parameters for the main floral dot 11 is as follows: surface size D1 of 0.3-0.6 mm², area ratio of 3%-7%, and embossing height H1 of 0.35-0.65 mm (this preferred height is determined by the thickness of the base paper; selecting a suitable embossing height H1 can create clear indentations on short-fiber base paper, while also resulting in low perforation rate, good wear resistance, and long service life). This combination has been verified through orthogonal experiments to optimize the overall performance of the product. The shape of the main floral dot 11 can be circular, square, rhomboid, or irregular polygonal, and the dimensional error of a single main floral dot 11 is controlled within ±0.05 mm² to ensure pattern consistency.

[0036] In this embodiment, the surface of the composite roller 2 is provided with a high density of composite dots 21, wherein the composite dots 21 satisfy the following characteristics: Feature 1: The surface size D2 of each composite point 21 is 0.01-0.05 mm². Its uniqueness lies in overcoming the problem of "coarse composite point 21 size" in existing technologies—the surface size of composite points 21 in existing technologies is mostly ≥0.2 mm², easily leading to an excessively high contact ratio for a single composite point. This invention, with its small-sized composite points and high-density distribution, ensures a contact ratio of 25-60% while avoiding localized pressure concentration. Furthermore, excessively small surface sizes (D2 < 0.01 mm²) result in insufficient processing precision (low engraving pass rate). The range of surface size D2 here represents a balance between "precise control of the contact ratio" and "processing feasibility": 0.01 mm² is the critical value for processing precision (laser engraving pass rate ≥95%), and 0.05 mm² is the upper limit critical value for the contact area (which, combined with the main flower point 11, can stably control the contact ratio ≤60%).

[0037] Feature 2: The area ratio of all composite points 21 on the surface of the composite roller 2 is 25%-60%. Its special feature is that it avoids the design misconception of "emphasizing the main pattern and neglecting the composite" in the existing technology. In the existing technology, the area ratio of composite points 21 is mostly <25%, and the lamination is achieved by relying only on the main pattern point 11, resulting in insufficient strength. This ratio is the optimal range for "overall interlocking strength" and "roller load": a ratio of ≥25% can form dense interlocking points, which, together with the contact area of ​​the main pattern point 11, can achieve "multi-point distributed load bearing"; a ratio of ≤60% can avoid pressure concentration on the surface of the composite roller 2 (roller surface pressure ≤0.8MPa) and extend service life.

[0038] Feature 3: The gap L2 between any two adjacent composite points 21 is 0.04-0.15mm. Its special characteristic lies in forming a "1:0.5-1:1.5" golden density ratio with the surface dimensions of the composite point 21, ensuring that the composite points 21 are evenly distributed and free from functional interference. When the gap L2 < 0.04mm, the composite points 21 are prone to edge adhesion during processing or use, resulting in abnormal contact area; when the gap L2 > 0.15mm, the density of the composite points 21 is insufficient, failing to cover 25%-60% of the contact requirements of the main flower point 11.

[0039] Feature 4: The embossing height H2 of composite point 21 is 0.06-0.12mm. Its special feature is that it forms a gradient design of "1:2-1:16" with the embossing height H1 (0.3-0.65mm) of the main flower point 11, which avoids "height conflict" and strengthens "mechanical interlocking". When the height is <0.06mm, composite point 21 is only attached to the surface of the base paper; when the height is >0.12mm, composite point 21 can easily penetrate the base paper and make direct rigid contact with the main flower point 11, resulting in accelerated wear of embossing roller 1.

[0040] The parameters of the composite point 21 and the main flower point 11 form a precise synergy—through the design of "small-sized composite points 21 + high-density distribution," structural support is provided for a contact area ratio of 25%-60%, ultimately achieving the characteristics of "soft feel" and "strong lamination." Specifically, the embossing composite is achieved through the pressing method of roller pressing the main flower point 11 and the composite point 21. The core of this method is to control the actual contact area between a single main flower point 11 and several composite points 21 to be 25% to 40% of the area of ​​a single main flower point 11. This contact area ratio is not randomly selected, but is optimized through a 3-factor, 4-level orthogonal experiment. The experiment uses the surface size D1 of the main flower point 11, the density of the composite point 21, and the pressing pressure as variables, and the feel hardness (Shore hardness) and lamination peel strength as evaluation indicators, ultimately determining the above-mentioned ratio range as the optimal parameter range.

[0041] To better understand the design of "the contact area ratio of the main flower point 11 and the composite point 21 is 25%-60%", further explanation is provided below.

[0042] The fundamental contradiction in existing technologies lies in the imbalance between contact area and product performance: while 100% full contact ensures strong lamination, concentrated pressure leads to tight aggregation of the base paper fibers, inevitably resulting in stiffening and grain formation; while when the contact area is less than 20%, although the stiffening problem can be alleviated, insufficient interlocking at the lamination points 21 leads to decreased lamination strength and increased susceptibility to perforation. Therefore, this embodiment achieves a balance between "pressure dispersion" and "strong interlocking" by controlling the contact area ratio between 25% and 60%. Pressure dispersion: Composite point 21 only contacts a part of the main flower point 11, avoiding the concentration of pressure in the entire area of ​​the main flower point 11. The degree of compression of the base paper fibers is reduced, the softness of the hand is improved, and the elongation of the base paper can be released through the uncontacted area of ​​the main flower point 11, completely solving the problem of stemming. In terms of strong interlocking: the 25%-40% contact area ensures that the composite point 21 and the main flower point 11 form sufficient mechanical interlocking. Combined with the high area ratio of 25%-60% of the composite mesh roller, the overall lamination strength is guaranteed and the anti-perforation performance is significantly improved.

[0043] In this embodiment, the surface size D1 (0.15-0.9 mm²) of the main floral dot 11 serves as the "basic carrier" of the contact area. If the main floral dot 11 is too large, even if the contact ratio remains unchanged, the actual contact area will still be too large, leading to hardening. The surface size D2 (0.01-0.05 mm²) and high-density distribution (gap L2 0.04-0.15 mm) of the composite dot 21 ensure "precise contact," ensuring that the composite dot 21 can uniformly cover 25% to 40% of the area of ​​the main floral dot 11, avoiding contact blind spots or excessive overlap. Therefore, the contact area ratio is not an isolated parameter; it needs to be precisely coordinated with the size and density of the main floral dot 11 and the composite dot 21.

[0044] Furthermore, to facilitate the understanding of the aforementioned contact area, the following verification and explanation will be provided in conjunction with specific orthogonal experiments.

[0045] Calculation formula: Contact area percentage (%) = (Total actual contact area of ​​a single main flower point 11 and composite point 21 ÷ Area of ​​a single main flower point 11) × 100%, where the area of ​​a single main flower point 11 (i.e., the nominal surface size of the main flower point 11) can be calculated by measuring the maximum outer contour size of the main flower point 11 with a diameter gauge; the total actual contact area of ​​a single main flower point 11 and composite point 21 is the sum of the areas of the indentation areas of the composite point 21 on the surface of a single main flower point 11 after pressing, measured by a high-precision fiber optic lens and image recognition software.

[0046] Based on the above calculation method, the orthogonal experimental data with the main flower point 11 surface dimension D1=0.4mm² and the composite point 21 surface dimension D2=0.012mm² as the basic parameters are shown in the table below: Experimental data shows that the product meets the requirements of "hand feel hardness ≤30HA, lamination peel strength ≥0.8N / 25mm, and no stemming" only when the contact area ratio is between 25% and 40%, thus verifying the non-obviousness and necessity of this parameter range.

[0047] To facilitate explanation, the following detailed implementation examples will be provided for further clarification.

[0048] Implementation Case 1: 1. Roller Preparation: Embossing roller 1 is laser-engraved to form several main floral dots 11 on its surface. The main floral dots 11 have the following characteristics: surface dimension D1 of 11 is 0.4 mm² (diameter 0.71 mm, dimensional error ±0.03 mm); center distance between adjacent main floral dots 11 is 1.21 mm (gap L1 is 0.5 mm); embossing height H1 is 0.4 mm (height error ±0.02 mm); and the total area of ​​all main floral dots 11 on the surface of embossing roller 1 accounts for 5%. Composite mesh roller 2 is laser-engraved to form circular composite dots 21. The composite dots 21 have the following characteristics: surface dimension D2 of 21 is 0.012 mm²; center distance between adjacent composite dots 21 is 0.22 mm (gap L2 is 0.096 mm); embossing height H2 is 0.08 mm; and the total area of ​​all composite dots 21 on the surface of composite mesh roller 2 accounts for 32%.

[0049] 2. Selection of base paper: Short fiber low grammage paper (usually specified weight of 8-20g / m², thickness of only 0.07-0.13mm thin base paper) is selected, and multiple layers of low grammage paper are stacked on the base paper.

[0050] 3. Product Testing: The finished embossed paper material is tested according to the following standards: ① Hand Hardness: Ten points are randomly selected in the embossed area using a Shore A hardness tester, with an average value of 29HA; ② Pattern Clarity: Observed with a 10x magnifying glass, the edges of the main floral pattern point 11 are clear; ③ Lamination Peel Strength: Tested using a tensile testing machine, the average value is 0.9N / 25mm; ④ Stranding and Perforation: Through visual observation (distance 50cm) and measurement with a thickness gauge (accuracy 0.001mm), the thickness difference in the embossed area is ≤0.05mm, there is no striation, and the perforation rate is 0%. The product meets the high-end standard of GB / T 20808-2011 "Tissue Paper".

[0051] Implementation Case 2: 1. Roller Preparation: The embossing roller 1 is laser-engraved to form several main floral dots 11 on its surface. Each main floral dot 11 has the following characteristics: surface dimension D1 of 11 is 0.6 mm² (side length 0.77 mm), center distance between adjacent main floral dots 11 is 1.57 mm (gap L1 is 0.8 mm), embossing height H1 is 0.45 mm, and the total area of ​​all main floral dots 11 on the surface of the embossing roller 1 accounts for 7%. The composite roller 2 is laser-engraved to form circular composite dots 21. Each composite dot 21 has the following characteristics: surface dimension D2 of 21 is 0.05 mm², center distance between adjacent composite dots 21 is 0.24 mm (gap L2 is 0.093 mm), embossing height H2 is 0.12 mm, and the total area of ​​the composite dot 21 accounts for 40%.

[0052] 2. Selection of base paper: Short fiber low grammage paper (usually specified weight of 8-20g / m², thickness of only 0.07-0.13mm thin base paper) is selected, and multiple layers of low grammage paper are stacked on the base paper.

[0053] 3. Product Testing: The finished embossed paper material is tested according to the following standards: ① Hand Hardness: Ten points are randomly selected in the embossed area using a Shore A hardness tester, and the hand hardness is 30HA; ② Pattern Clarity: Observed with a 10x magnifying glass, the edges of the main pattern point 11 are clear; ③ Lamination Peel Strength: Tested using a tensile testing machine, the average value is 1.1N / 25mm; ④ Stranding and Perforation: Through visual observation and thickness measurement, the thickness difference in the embossed area is ≤0.05mm, there is no striation, and the perforation rate is 0%. The product meets the high-end standard of GB / T 20808-2011 "Tissue Paper".

[0054] Comparative Example 1 - Comparative Experiment Using Convex-to-Light Roller Process: Using the same main pattern point 11 parameters and base paper as in Implementation Case 1, only the composite wire roller 2 was replaced with a light roller, the pressing pressure was 0.5 MPa, and other parameters remained the same. The product test results were as follows: the hand hardness was 52 HA (far exceeding the standard of ≤30 HA of this invention), continuous longitudinal fraying occurred in the main pattern point 11 area (fraying height 0.15 mm), and the lamination peel strength was 1.0 N / 25 mm. Although the firmness met the standard, the softness and appearance could not meet the requirements of mid-to-high-end products.

[0055] Comparative Example 2 - A comparative experiment using a convex dot roller process: Using the same parameters for the main floral dot 11 and the same base paper as in Example 1, the composite roller 2 was replaced with a conventional dot roller (composite dot 21 surface size 0.25mm², gap 0.3mm, area ratio 20%), and the pressing pressure was 0.5MPa. Test results: The contact area between the main floral dot 11 and the composite dot 21 accounted for 18%, the hand hardness was 39HA, but the peel strength was only 0.6N / 25mm. The main floral pattern showed local defects due to the large gap between the composite dots 21, and the perforation rate was 1.2%, failing to meet the requirements for firmness and integrity.

[0056] Comparative experiments between Case 1, Case 2, and Control Case 1, Control Case 2 verified the superiority of the core process of "small-sized main flower point 11 + high-density composite point 21 + 25%-60% contact area ratio". The specific summary is as follows: Comparison Table of Core Process Parameter Differences Based on the core performance data of Implementation Case 1 and Comparative Examples 1 and 2, the advantage of this invention lies in the "balance of contradictory performance": 1. Balance between feel and strength: Comparative Example 1 (smooth roller) has a peel strength of 1.0 N / 25 mm but a hardness of 52 HA, while Comparative Example 2 (traditional dot roller) has a hardness of 31 HA but a peel strength of only 0.6 N / 25 mm; while Implementation Case 1 achieves "hardness of 29 HA + peel strength of 0.9 N / 25 mm", which is both soft and strong, solving the pain point of existing technology that is "hard but not strong, strong but hard".

[0057] 2. Pattern integrity: In contrast to Example 2, the pattern is incomplete due to the large gap (0.3mm) between composite dots 21; in Implementation Case 1, the high-density distribution of composite dots 21 (0.1mm gap) balances visual effect and service life.

[0058] In summary, the core innovation of this invention, "25%-60% contact area ratio," is not a simple parameter adjustment, but rather achieves a balance of multiple performances that cannot be achieved by existing technologies through precise coordination with the size and density of the main flower point 11 and the composite point 21. Moreover, it has high process stability, wide adaptability, and significant industrial application value.

[0059] See appendix Figure 4 and 5 As shown, in this embodiment, the composite points 21 on the surface of the composite roller 2 can be arranged in a spaced or disordered manner. For ease of understanding, the following will provide further explanation in conjunction with the specific structure and principle.

[0060] In this embodiment, the spacing arrangement uses a "layered array unit A0" as the basic arrangement unit. Specifically, several layered array units A0 are distributed on the surface of the composite roller 2. Each layered array unit A0 consists of several layers of nested sub-units A1. Each layer of sub-units A1 is distributed at intervals along the unit radial direction or a preset trajectory, with the interval distance consistent with the adjacent gap L2 of the composite point (0.04-0.15mm) to ensure uniform pressure transmission. The shape of the sub-units A1 can be flexibly selected, that is: each layer of sub-units A1 can be coaxial or non-coaxial; the shape of each layer of sub-units A1 is a ring, triangle, ellipse or other closed contour (see Appendix). Figure 9-11 The different closed contours of the layered array units A0 are shown. Secondly, the contour dimensions of each sub-unit A1 increase radially along the layered array unit A0. The number of composite points in the inner sub-unit A1 is less than that in the outer sub-unit—because the outer sub-unit A1 has a longer contour perimeter, increasing the number of composite points maintains density uniformity and avoids sparse composite points in the outer region. Therefore, through the design of "layered pattern + layered sub-unit A1," without changing the core parameters such as the surface size, total density, and area ratio of the composite points 21, the uniformity of pressure transmission is further optimized—improving the local stress during the pressing of the composite points 21 and the main flower point 11. The staggered arrangement of the layered sub-units A1 prevents the composite points 21 from concentrating into hard areas, effectively dispersing the pressing stress, improving the contact compatibility between the composite points 21 and the main flower point 11, and extending the service life.

[0061] Furthermore, the relative positional relationship between two adjacent hierarchical array units A0 can be any one of tangency, partial overlap, or interval arrangement. For ease of explanation, see the attached diagram. Figure 6-8 Taking the annular subunit A1 as an example, the three positional relationships of tangency, partial overlap, or spacing are explained and illustrated. To facilitate the representation of different regions, the appendix of this application... Figure 4-8 Different graphical representations were used for composite points in different regions, but the actual composite points on the surface of the composite roller strictly followed the above-mentioned parameter characteristics.

[0062] See appendix Figure 6As shown, the positional relationship is tangential: the circumferential edges of two adjacent layered array units A0 are exactly in contact, and the spacing between the composite points (i.e., the composite points of the outermost sub-unit A1) at the edges of the two layered array units A0 is consistent with the adjacent gaps of the internal composite points. Alternatively, those skilled in the art can also use a derived method, namely: the outermost sub-unit A1 between two layered array units A0 shares several composite points 21 at the tangential position.

[0063] See appendix Figure 7 As shown, positional relationship 2 - local overlapping arrangement: the circumferential edges of two adjacent layered array units A0 intersect, and some areas overlap to form an overlapping area S0 (preferably, the overlapping area is ≤ 30% of the area of ​​a single layered array unit A0). Each composite point 21 in the overlapping area S0 still maintains the core parameters such as surface size, total density and area ratio.

[0064] See appendix Figure 8 As shown, the positional relationship is three-interval arrangement: the circumferential edges of two adjacent layered array units A0 do not touch and have a certain interval.

[0065] In summary, the surface dimension D2 of all composite points in the three arrangement methods is always 0.01-0.05 mm², and the distance between any two adjacent composite points is ≥0.08 mm and ≤0.15 mm, which does not deviate from the core parameter requirements.

[0066] In this embodiment, the surface of the composite roller 2 is covered with a number of composite points 21 in the remaining area S1 except for the area covered by the layered array unit A0. The parameter characteristics of the composite points in this area S1 are consistent with the parameter characteristics of the composite points 21 in the layered array unit A0, thus ensuring that the surface of the composite roller 2 is covered with composite points 21 and avoiding blank areas.

[0067] In this embodiment, the core of the disordered distributed arrangement is "random fluctuation of parameters". Specifically, the composite points 21 are randomly distributed on the surface of the composite roller 2 without fixed unit boundaries. The surface size, adjacent gap and embossing height of each composite point 21 fluctuate independently and randomly within the corresponding rated range. They can be large or small, without the need for unified parameters or concentration in a specific sub-interval. The random fluctuation of a single composite point does not affect the overall parameter compliance - the overall area ratio of composite points is still 25%-60%, so that the area ratio of the pressing area between a single main flower point and a composite point is still 25%-60%. Through "local randomness and overall controllability", the technical effect equivalent to the interval arrangement is achieved.

[0068] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any modifications or variations made by those skilled in the art, without departing from the scope of the present invention, using the disclosed technical content, are equivalent embodiments of the present invention. Therefore, all equivalent changes made based on the concept of the present invention without departing from the scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A fine-textured composite embossing device, wherein an embossing roller (1) and a composite wire roller (2) are used to emboss and composite multiple layers of base paper, characterized in that: The embossing roller (1) has a main floral pattern on its surface, which is composed of a number of main floral dots (11) arranged at intervals. The dotted structure of the main floral pattern satisfies the following characteristics: • The surface dimension D1 of each main flower point (11) is 0.15-0.9 mm²; • The area ratio of all main flower points (11) on the surface of the embossing roller (1) is 1.5%-10%; The surface of the composite roller (2) is provided with a plurality of composite points (21), wherein the composite points (21) satisfy the following characteristics: • The surface dimension D2 of each composite point (21) is 0.01-0.05 mm²; • The area of ​​all composite points (21) on the surface of the composite roller (2) accounts for 25%-60%; During embossing, the area of ​​the embossed region between a single main flower point (11) and several composite points (21) accounts for 25%-60%.

2. The fine-textured composite embossing device according to claim 1, characterized in that: The gap L1 between any two adjacent main flower points (11) is 0.3-1mm.

3. The fine-textured composite embossing device according to claim 2, characterized in that: The embossing height H1 of the main flower point (11) is 0.3-0.65mm.

4. The fine-textured composite embossing device according to claim 1, characterized in that: The surface size D1 of the main flower point (11) is 0.3-0.6 mm², and the area ratio of all the main flower points (11) on the surface of the embossing roller (1) is 3%-7%.

5. The fine-textured composite embossing device according to claim 1, characterized in that: The gap L2 between any two adjacent composite points (21) is 0.04-0.15 mm.

6. The fine-textured composite embossing device according to claim 5, characterized in that: The embossing height H2 of the composite point (21) is 0.06-0.12 mm.

7. The fine-textured composite embossing device according to claim 1, characterized in that: The composite points (21) on the surface of the composite roller (2) are arranged at intervals. The characteristics of the interval arrangement are: taking "layered array unit (A0)" as the basic arrangement unit, several layers of array units (A0) are distributed on the surface of the composite roller (2), and the relative position relationship between two adjacent layers of array units (A0) is any one of tangency, partial overlap or interval arrangement; a single layer of array unit (A0) is composed of several layers of nested sub-units (A1), and each layer of sub-units (A1) is distributed at intervals along the radial direction of the layered array unit (A0). Each layer of sub-units (A1) is formed by several composite points (21) arranged along the contour trajectory of the sub-unit (A1).

8. The fine-textured composite embossing device according to claim 7, characterized in that: Each layer of sub-units (A1) can be arranged coaxially or non-coaxially; the shape of each layer of sub-units (A1) is any closed contour among annulus, triangle, and ellipse.

9. The fine-textured composite embossing device according to claim 7, characterized in that: The surface of the composite roller (2) is covered with several composite points (21) in the area other than the area covered by the layered array unit (A0). The parameter characteristics of the composite points (21) in this area are consistent with the parameter characteristics of the composite points (21) in the layered array unit (A0).

10. The fine-textured composite embossing device according to claim 1, characterized in that: The composite points (21) on the surface of the composite roller (2) are arranged in a disordered distributed manner. The disordered distributed arrangement is characterized by the following: the composite points (21) have no fixed unit boundaries on the surface of the composite roller (2) and are randomly distributed without any rules. The surface size, adjacent gap, and embossing height of each composite point (21) fluctuate independently and randomly within the range of the corresponding parameter characteristics.

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