Composite embossing method, composite printing roller set and printing paper product

Abstract

The invention discloses a composite embossing method, a composite printing roller set and a printing paper product, and belongs to the technical field of household paper production equipment. According to the composite embossing method, first body paper and second body paper are jointly gathered into a gap between a first embossing roller and a second embossing roller, a printing boss on the first embossing roller is used for pressing the surface of the first body paper, and at least one printing pattern composed of a plurality of first indentations is formed; the composite fine points on the second embossing roller are pressed on the surface of the second body paper and located in the area of the first indentations, and a plurality of second indentations are formed. The first indentation and the second indentation are actually obtained by thinning partial areas of respective raw paper, so that the overall thickness of the composite paper cannot be influenced, and the problems of attractiveness and thickness are well considered. In addition, the first interwoven layer and the second interwoven layer are formed at the bottom of the first indentation, so that the base paper is compounded more firmly.

Description

Technical Field

[0001] The invention belongs to the technical field of household paper production equipment, and more specifically, relates to a composite embossing method, a composite printing roller group and printed paper products. Background Art

[0002] Paper towels are a necessity in people's daily life. Paper towels are usually made of two or more layers of base paper. At the same time, in order to enhance the water absorption and decorative effect of paper towels, many paper towels are also embossed with printed patterns on the surface to meet market demand. Traditional embossed paper towels are generally glued by spraying glue, but the glue is often toxic and corrosive, so using such paper towels will endanger people's health. In addition, the glue will harden after solidification, which will affect the feel of use.

[0003] In order to solve the defects brought by the above-mentioned glue lamination, some glue-free lamination paper products and equipment have appeared on the market. The main working principle is to squeeze multiple base papers through mechanical pressure so that the fibers between the base papers are intertwined, thus forming a glue-free lamination.

[0004] In some schemes, a "point-to-flat" glue-free lamination method is adopted, that is, the base paper is first pre-embossed to form patterns; then, a number of composite protrusions on the surface of a printing roller and the smoothing roller surface of another smooth roller are used to extrude and laminate multiple sheets of base paper in the pattern area formed by pre-embossing.

[0005] Although this "point-to-flat" lamination method can achieve glue-free lamination of paper, when the two base papers are pressed together at the tangent point between the printing roller and the smooth roller, the pre-pressed patterns on the base paper close to the smooth roller will be squeezed to a certain extent, resulting in unclear patterns and poor embossing effect.

[0006] In some schemes, a "point-to-point" glue-free lamination method is adopted, that is, the base paper is first pre-embossed to form a pattern; then, a number of composite protrusions on a printing roller and a number of composite protrusions on the surface of another printing roller are extruded and laminated in the pattern area formed by the pre-embossing.

[0007] This composite method can effectively avoid the damage to the pattern formed by pre-pressing and ensure the integrity of the pattern formed by pre-pressing. However, this "point-to-point" composite method has high precision requirements on the relative position of the composite protrusions on the two printing rollers, and it is necessary to ensure that the composite protrusions on the two rollers are in a one-to-one correspondence state, which greatly increases the difficulty of actual production operation.

[0008] In order to solve the above problems, the "fine grain composite" technology has emerged in the prior art, that is, a plurality of printing bosses on the printing roller cooperate with the rubber roller to form a pre-printed pattern on the base paper; and then the printing bosses on the printing roller cooperate with the composite fine dots on another fine grain roller to form multiple composite points in the area of ​​the pre-printed pattern. This can well ensure the integrity of the printed pattern, while reducing the position requirements between the printing bosses and the composite fine dots.

[0009] It can be seen that there are related disclosures about the glue-free composite embossing technology in the prior art, but there is still room for optimization. For example, in the existing glue-free composite embossing technology, each layer of base paper is pre-formed with a pattern before lamination (generally formed by the extrusion of the printed protrusions on the rubber roller and the printing roller), and then the depressions of the pattern are pressed and laminated, so that an air layer is formed between adjacent composite areas of the composited paper. Although the existence of this air layer can improve the appearance of the composite paper towel, it will also cause the volume of the composite paper towel to expand too much, which is not conducive to saving packaging materials and transportation costs. Especially for small-packaged paper products that are carried with you, in the same packaging space, the number of paper towels is sacrificed due to the increase in the thickness of a single paper towel, which greatly reduces customer satisfaction. Summary of the invention

[0010] 1. Problems to be solved

[0011] In view of the problem that the existing glue-free composite device cannot well balance the aesthetics and thickness, the present invention provides a composite embossing method, a composite printing roller group and a printed paper product. In the present invention, the thickness of the base paper is used to perform a thinning process on the base paper to form an embossed texture with a certain shape; at the same time, the thickness will not be increased, so that the aesthetics and thickness are well balanced.

[0012] 2. Technical solution

[0013] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0014] A composite embossing method of the present invention,

[0015] The roller group used comprises a first pattern roller and a second pattern roller, the roller surface of the first pattern roller is provided with a plurality of printing bosses, and the roller surface of the second pattern roller is provided with a plurality of composite fine dots densely distributed at intervals;

[0016] During processing, the distance H between the top of the printing boss and the roller surface of the second pattern roller is controlled to be smaller than the overlapping thickness of the base paper that is fed together; the first base paper and the second base paper are fed together into the gap between the first pattern roller and the second pattern roller, and the first base paper and the second base paper are squeezed by the first pattern roller and the second pattern roller, and the printing and compounding work is completed at the same time;

[0017] Among them, the printing boss is pressed on the surface of the first base paper to form at least one printing pattern composed of a plurality of first indentations; the composite fine dots corresponding to the printing boss are pressed on the surface of the second base paper to form a plurality of second indentations, and a first interlaced layer is pressed and formed in the area where the bottom of the first indentation overlaps with the second indentation.

[0018] In some embodiments, a second interwoven layer is formed by pressing in a non-overlapping region between the bottom of the first indentation and the second indentation.

[0019] In some embodiments, the height of the composite fine dots is greater than the thickness of the second base paper, so that the second indentations formed by the composite fine dots can be more clearly presented on the first base paper.

[0020] In some embodiments, the height of the composite fine dots is 0.05-0.2 mm.

[0021] In some embodiments, the first base paper and / or the second base paper are pre-pressed with a plurality of third indentations; the plurality of third indentations form a printed pattern or concave dots having a certain shape.

[0022] In some embodiments, the pressing depth of the third indentation is less than the pressing depth of the first indentation, and when the third indentation is in the printing boss area, it can be further pressed and compounded on the first indentation.

[0023] A composite printing roller set of the present invention comprises a first pattern roller and a second pattern roller abutting against each other, a plurality of printing bosses are formed on the roller surface of the first pattern roller, and a plurality of composite fine dots are densely distributed on the roller surface of the second pattern roller; wherein:

[0024] The distance H between the top of the printing boss and the roller surface of the second flower roller is 0.08-0.28mm, so that a first pressing area is formed between the printing boss and the composite fine dots, and the first pressing area forms fine dots on the paper and fills the corresponding texture of the printing boss; a second pressing area is formed between the printing boss and the roller surface of the second flower roller.

[0025] In some embodiments, the height of the composite fine dots protruding from the surface of the second flower roller is 0.10 mm to 0.25 mm.

[0026] In some embodiments, the pressing area of ​​the composite fine point is less than 0.1 mm 2 , and the gap between adjacent composite fine points is 0.05-0.5mm.

[0027] In some embodiments, at least one pre-embossing roller group consisting of a third pattern roller and a rubber roller is further included, and a plurality of pre-printed protrusions are distributed on the third pattern roller; wherein the pre-printed protrusions form a printing pattern with a certain shape, or a series of convex points, or a combination of the printing pattern and the convex points.

[0028] In some embodiments, the height of the pre-printing protrusion is less than the height of the printing boss.

[0029] In some embodiments, the height of the printed platform is 0.8-2.5 mm; the height of the pre-printed protrusion is 0.5-2.0 mm.

[0030] The composite printing roller set of the present invention comprises a first pattern roller and a second pattern roller which abut against each other, a plurality of printing bosses are arranged on the roller surface of the first pattern roller, and a plurality of composite fine dots are densely distributed on the roller surface of the second pattern roller; wherein:

[0031] A first pressing area is formed between the printing boss and the composite fine dots, which form fine dots on the paper and fill the patterns corresponding to the printing boss; a second pressing area is formed between the printing boss and the roller surface of the second flower roller; and the height of the composite fine dots protruding from the roller surface of the second flower roller is 0.08-0.28mm.

[0032] A printed paper product of the present invention comprises a first base paper and a second base paper which are mutually laminated, wherein the first base paper and the second base paper are respectively formed with a first indentation and a second indentation on their opposite surfaces under mechanical pressing of the same roller group; wherein:

[0033] The densely distributed second indentations are filled in the first indentation area, and a first interlaced layer is formed in the overlapping area of ​​the two indentations.

[0034] In some embodiments, a second interlaced layer is formed in a non-overlapping region between the bottom of the first indentation and the second indentation.

[0035] In some embodiments, the first base paper and the second base paper are partially layered within the first indentation area; the portions within the non-first indentation area are in a state of mutual adhesion; and the depth of the first indentation and the second indentation does not exceed the thickness of the respective base papers.

[0036] In some embodiments, a third impression is formed on the first base paper and / or the second base paper, and the area of ​​the third impression is larger than the area of ​​the second impression; the third impression forms a printing pattern with a certain shape, or a series of concave dots, or a combination of the printing pattern and concave dots.

[0037] In some embodiments, the third impression is a series of concave dots, and the concave dots fill the entire area of ​​the base paper surface other than the first indentation, or a boundary is left between the concave dots and the area where the first indentation forms a printed pattern.

[0038] 3. Beneficial effects

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) A composite embossing method of the present invention utilizes the thickness of the base paper itself to press a first indentation on the first base paper and a second indentation on the second base paper, and simultaneously completes the composite operation between the two base papers; since the first indentation and the second indentation are actually obtained by thinning a part of the area of ​​each base paper, they do not affect the overall thickness of the composite paper, thus taking into account both the aesthetics and thickness issues. In addition, since the first interlaced layer and the second interlaced layer are formed at the bottom of the first indentation, the composite between the base papers is more secure.

[0041] (2) The composite printing roller group of the present invention can simultaneously complete the printing and compounding operations between the base papers by using the cooperation of two flower rollers, and can obtain printed paper products with printed patterns without pre-printing, while ensuring the beauty of the paper products, and will not excessively increase the thickness of the paper products. In addition, by controlling the distance between the top of the printing boss and the roller surface of the second flower roller, the compounding area between the base papers can be greatly increased, ensuring the firmness of the compounding between the base papers; at the same time, the risk of excessive wear or even breakage of the composite fine points caused by the large pressing force required for printing can be eliminated.

[0042] (3) A printed paper product of the present invention can form a printed pattern of a certain shape on the surface of the first base paper through the first indentation, and the shape of the second indentation can be presented on the first base paper through the first indentation, which can effectively enrich the beauty of the paper product; at the same time, the parts of the first base paper and the second base paper in the first indentation area are in a mutually laminated state, which can effectively ensure the laminated area; and the parts in the non-first indentation area are in a mutually fitted state, avoiding the existence of an air layer, which is beneficial to ensure the thickness of the composite paper. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of a composite printing roller group of the present invention;

[0044] Figure 2 for Figure 1 A local enlarged schematic diagram of the middle A;

[0045] Figure 3 This is a schematic diagram of the coordination of the first and second pattern rollers after the roller surfaces are unfolded in the present invention;

[0046] Figure 4 Another structural schematic diagram of a composite printing roller group in the present invention;

[0047] Figure 5 It is a structural schematic diagram of a printed paper product in the present invention;

[0048] Figure 6 for Figure 5 A local enlarged schematic diagram of point A in the middle.

[0049] Figure 7 FIG. 1 is a distribution mode of the concave points on the printed paper product of the present invention;

[0050] Figure 8 FIG. 2 is another distribution mode of the concave points on the printed paper product of the present invention.

[0051] In the figure: 100, first flower roller; 110, printing boss;

[0052] 200, second flower roller; 210, composite fine point;

[0053] 300, pre-embossing roller group;

[0054] 400, first base paper; 410, first indentation;

[0055] 500, second base paper; 510, second indentation;

[0056] 610, first interlaced layer; 620, second interlaced layer. DETAILED DESCRIPTION

[0057] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings.

[0058] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0059] Regarding the "fine grain composite" technology that appears in the prior art, first use a number of printing bosses on the printing roller to cooperate with the rubber roller to form pre-printed patterns on the base paper; then the printing bosses on the printing roller cooperate with the composite fine dots on another fine grain roller to form multiple composite points in the area of ​​the pre-printed patterns; due to the small size of the composite points and the high pressure during pressing, fine grain points can be easily formed. Its advantage is that it can be easily controlled to ensure the integrity of the printed patterns, while reducing the position requirements between the printing bosses and the composite fine dots. However, the problem is that the thickness of the formed product is large, and the number of papers contained in the same volume is reduced.

[0060] As for the thickness problem, the optimization solution that can be thought of is to change the smooth roller to a fine-grain roller and directly cooperate with the printing roller to reduce the thickness. However, due to the pressure problem, the fine grain will be worn out quickly; if the pressure is too low, the positive pattern cannot be clearly displayed, resulting in this solution being unable to be applied in actual production.

[0061] The present invention provides a composite embossing method, a composite printing roller set and a printed paper product, the main purpose of which is to form a printed pattern on the surface of the printed paper product and fill it with fine dots to improve the clarity. At the same time, it should be noted that the printed pattern in the present invention can be a graphic, a text, or a combination of the two, which can be determined according to actual needs.

[0062] The present invention is further described below in conjunction with specific embodiments.

[0063] In a composite embossing method of this embodiment, the first base paper 400 and the second base paper 500 overlapped with each other can be printed and composited at the same time under the pressing of the first flower roller 100 and the second flower roller 200. Among them, a plurality of printing bosses 110 are provided on the roller surface of the first flower roller 100, and the plurality of printing bosses 110 can be combined into at least one printing pattern. A plurality of composite fine dots 210 are densely distributed on the roller surface of the second flower roller 200, and the pressing surface area of ​​the printing bosses 110 is more than twice that of the composite fine dots 210, so that each printing boss 110 can be extruded and matched with multiple composite fine dots 210. At the same time, the distance H between the top of the printing boss 110 and the roller surface of the second flower roller 200 is less than the overlapping thickness of the base paper that is merged together.

[0064] It is worth mentioning that the first base paper 400 and the second base paper 500 in this embodiment can be single-layer base paper or multi-layer base paper, which is not specifically limited here.

[0065] A composite embossing method of this embodiment comprises the following specific steps:

[0066] The first base paper 400 and the second base paper 500 are put into the gap between the first pattern roller 100 and the second pattern roller 200, and the printing boss 110 is used to press the surface of the first base paper 400 to form at least one printing pattern composed of a plurality of first indentations 410.

[0067] The composite fine dots 210 are pressed on the surface of the second base paper 500 and in the area of ​​the first indentation 410 to form a plurality of second indentations 510. Since the distance H between the printing boss 110 and the roller surface of the second flower roller 200 is less than the overlapping thickness of the base papers that are fed together, a first interlaced layer 610 can be formed by pressing in the area where the bottom of the first indentation 410 overlaps with the second indentation 510 between the first base paper 400 and the second base paper 500. In the area where the bottom of the first indentation 410 does not overlap with the second indentation 510, multiple layers of base paper will also be squeezed to form a second interlaced layer 620, and the pressing force of the first interlaced layer 610 is greater than the pressing force of the second interlaced layer 620 to ensure the firmness of the composite between the first base paper 400 and the second base paper 500.

[0068] It should be noted that the distance H between the printing boss 110 and the roller surface of the second pattern roller 200 can be adjusted according to the thickness (i.e., the number of layers) of the base paper to be laminated. When a single layer of base paper is used for lamination, the distance H can be appropriately reduced; and when multiple layers of base paper are used for lamination, the overlapping thickness of each base paper will also increase; at this time, the value of the distance H can be appropriately increased to form a deeper indentation, so that the printed pattern formed by the indentation is clearer and has a stronger three-dimensional effect.

[0069] Specifically in this embodiment, the first base paper 400 and the second base paper 500 are both double-layer base paper. Since the first base paper 400 and the second base paper 500 in this embodiment are not pre-printed, the stacking thickness of each base paper can be approximately regarded as the sum of the thickness of each base paper. That is, the stacking thickness of the four base papers in this embodiment is about 0.2-0.28mm (usually each layer of facial tissue weighs 11-14g and has a thickness of about 0.05-0.07mm). Therefore, the spacing H between the printing boss 110 and the roller surface of the second flower roller 200 can be controlled within the range of 0.08-0.28mm, for example, 0.09mm, 0.14mm, 0.20mm, 0.26mm, etc. The control of this spacing ensures the clarity of the indentation and the pressure during compounding on the one hand, and ensures that the base paper is not crushed on the other hand.

[0070] In some embodiments, the height of the composite fine dots 210 should be greater than the thickness of the second base paper 500. At the same time, under the premise that the second base paper 500 is not crushed, the height of the composite fine dots 210 should be as large as possible, so that the second indentation 510 formed by the composite fine dots 210 can be more clearly presented on the first base paper 400, so as to further ensure the clarity of the printed pattern.

[0071] However, considering that in this embodiment, printing and compounding are carried out simultaneously, in order to be able to form an indentation on the original thickness of the base paper, the pressing pressure between the two pattern rollers should be greater than the pressure of the traditional pre-pressing pattern and then compounding. At this time, if the height of the composite fine point 210 is too large, it will cause excessive wear and even breakage of the composite fine point 210. For this reason, in this embodiment, the height of the composite fine point 210 is controlled to 0.05-0.2mm, for example, 0.06mm, 0.13mm, 0.18mm, etc. On the one hand, it can ensure the clarity of the indentation, and on the other hand, it is conducive to extending the service life of the composite fine point 210.

[0072] In addition, in some cases where there is no strict requirement for packaging thickness, such as kitchen paper and bathroom paper, before the first base paper 400 and the second base paper 500 are fed into two pattern rollers for printing and lamination, the first base paper 400 can be pre-pressed with a plurality of third indentations to further enrich the appearance of the printed paper product and improve its water absorption. Of course, the second base paper 500 can also be pre-pressed with a plurality of third indentations.

[0073] The third indentation is further described in detail below by taking the third indentation formed on the first base paper 400 as an example. The third indentation can form a printing pattern with a certain shape, or a series of concave points can be formed on the paper surface, or a combination of the two. At the same time, it should be noted that when the third indentation is used to form a printing pattern, the third indentation needs to be staggered with the first indentation 410 to prevent the pre-formed third indentation from being destroyed when the first indentation 410 is pressed.

[0074] In some embodiments, in order to minimize the impact on the overall thickness of the printed paper, the pressing depth of the third indentation may be smaller than the pressing depth of the first indentation 410 .

[0075] The composite embossing method of the present embodiment essentially utilizes the thickness of the superimposed base paper itself, presses a first indentation 410 on the first base paper 400, presses a second indentation 510 on the second base paper 500, and completes the composite operation between the two base papers at the same time; since the first indentation 410 and the second indentation 510 are actually obtained by thinning partial areas of the respective base papers, they do not affect the overall thickness of the composite paper, thereby taking into account the issues of aesthetics and thickness; at the same time, the printed pattern also has a higher clarity.

[0076] In order to implement the above-mentioned composite embossing method, this embodiment provides a composite printing roller group.

[0077] like Figure 1 , Figure 2As shown, a composite printing roller group of this embodiment includes a first flower roller 100 and a second flower roller 200 that are against each other and rotate in opposite directions. Among them, a plurality of printing bosses 110 are formed on the roller surface of the first flower roller 100, and the plurality of printing bosses 110 form at least one printing pattern with a certain shape. A plurality of composite fine dots 210 are densely distributed on the roller surface of the second flower roller 200. At the same time, at the composite position, the composite fine dots 210 cooperate with the printing bosses 110 to press and print the first base paper 400 and the second base paper 500 that are jointly introduced, and a series of fine grain dots are filled in the grain formed by the printing bosses 110. The "composite position" here means that when the printing bosses 110 and the composite fine dots 210 rotate to a certain position with their respective roller bodies, the gap between the printing bosses 110 and the composite fine dots 210 is the smallest, and the first base paper 400 and the second base paper 500 are jointly introduced here for pressing and compounding, and this place is the composite position. At the same time, it should be noted that the distance H between the pressing surface of the printing boss 110 and the roller surface of the second flower roller 200, and the distance h between the pressing surface of the printing boss 110 and the pressing surface of the composite fine point 210 mentioned below are all for the composite position.

[0078] In some embodiments, the above-mentioned printing bosses 110 may be in the shape of convex dots or convex lines; the convex lines may be straight lines, curves, or a combination thereof. At the same time, the convex lines may be segmented, or may run through the entire axial direction of the first flower roller 100, or a combination of the two. The specific shape and size of the convex lines shall be based on the desired printing pattern, and are not specifically limited here.

[0079] In some embodiments, the composite fine dots 210 may be convex dots or convex lines, but their pressing surface is smaller than the printed boss 110. The specific pressing area of ​​the composite fine dots 210 may be determined according to actual production requirements. Generally, the pressing surface area of ​​the composite fine dots 210 does not exceed 0.2 mm. 2 , and when the composite fine dots 210 are in the shape of convex lines, the length and width of the pressed surface do not exceed 0.6 mm. It is worth mentioning that the pressed surface here refers to the end surfaces of the printing boss 110 and the composite fine dots 210 that are close to each other when they are squeezed and matched with each other at the composite position; it can also be understood as the top of each. At the same time, a plurality of composite fine dots 210 do not need to form a printing pattern with a certain shape, but are only used to re-outline and press composite in the area of ​​the printing pattern formed by the printing boss 110. It can also be understood that a plurality of composite fine dots 210 do not form a completely new printing pattern, but are only outlined along the inside of the printing pattern formed by the printing boss 110, so that the printing pattern formed by the printing boss 110 can be presented more clearly on both the front and back sides of the composite paper product.

[0080] Specifically, Figure 3 , Figure 5 As shown, (for the convenience of display, Figure 3 In this embodiment, at the composite position, the spacing h between the pressing surface of the printing boss 110 and the pressing surface of the composite fine point 210 is smaller than the overlapping thickness D of the first base paper 400 and the second base paper 500, so that a first pressing area can be formed between the printing boss 110 and the composite fine point 210. When the first base paper 400 and the second base paper 500 are not pre-formed with patterns, the overlapping thickness D is the superposition of the thickness of each base paper.

[0081] When the first base paper 400 and the second base paper 500 are combined into the first pressing area, the printing boss 110 presses a first indentation 410 which is concave from the outside to the inside on the first base paper 400. The composite fine point 210 presses a second indentation 510 which is concave from the outside to the inside on the second base paper 500, and a first interlaced layer 610 is formed at the junction of the second indentation 510 and the first indentation 410. In the area of ​​the first interlaced layer 610, the fibers of the first base paper 400 and the second base paper 500 are interlaced with each other, thereby presenting a layered state, and the two base papers are composited together.

[0082] In this embodiment, the first indentation 410 and the second indentation 510 are actually formed by thinning the parts of the respective base papers at the composite position. Therefore, the first indentation 410 will not protrude from the inner surface of the first base paper 400 while forming the pattern. Therefore, the thickness of the first base paper 400 itself will not be increased. At the same time, since the second indentation 510 is formed in the area covered by the first indentation 410, although the second indentation 510 will not form a completely new pattern, when the base paper is relatively thin, the shape of the second indentation 510 itself will be presented on the first base paper 400 through the first indentation 410, so that the pattern formed by the first indentation 410 is finer and clearer, and the three-dimensional sense is stronger, which greatly increases the beauty of the composite paper.

[0083] In some embodiments, at the composite position, the spacing H between the pressing surface of the printing boss 110 and the roller surface of the second pattern roller 200 (that is, the concave area between adjacent printing bosses 110) is also smaller than the overlapping thickness D of the first base paper 400 and the second base paper 500, so that a second pressing area can be formed between the printing boss 110 and the roller surface of the second pattern roller 200. When the first base paper 400 and the second base paper 500 are merged into the second pressing area, the merged base papers can also be extruded and composited to form a second interlaced layer 620. Although the pressing strength of the second interlaced layer 620 is smaller than that of the first interlaced layer 610, it can also achieve a composite effect.

[0084] Similarly, the second interlaced layer 620 is formed by compressing two base papers, and thus does not increase the thickness of the base papers. In other words, the laminated papers are in a layered state at the bottom of the entire first indentation 410, which greatly increases the layering area between the base papers and effectively improves the firmness of the laminate. At the same time, the laminated papers in the non-first indentation 410 area are in a mutually attached state, so that the overall thickness is roughly the same as the overlapping thickness before the laminate.

[0085] In some embodiments, at the composite position, the spacing H between the lamination surface of the printing boss 110 and the roller surface of the second flower roller 200 is 0.08-0.28 mm. This is because the thickness of a single layer of base paper is generally about 0.05-0.07 mm, and when the first base paper 400 and the second base paper 500 are both single sheets of base paper, the overlapping thickness D is about 0.10-0.14 mm. At this time, the H value takes the minimum value of 0.08 mm, which is not only less than the overlapping thickness of 0.10 mm, but also ensures that the base paper is subjected to sufficient extrusion force in the second lamination area to form the second interlaced layer 620. Since the composite fine point 210 is protruding from the roller surface of the second flower roller 200, the spacing between the composite fine point 210 and the printing boss 110 is less than H, so that the base paper introduced in the first lamination area is subjected to a greater extrusion force to form a first interlaced layer 610 with a better lamination effect. Of course, the specific value of the H value can be adjusted according to the actual overlapping thickness of the first base paper 400 and the second base paper 500 .

[0086] In some embodiments, in order to ensure that the second indentation 510 on the second base paper 500 can be more clearly presented on the first base paper 400, the height of the composite fine dots 210 should be as large as possible without the second base paper 500 being crushed, so that the second indentation 510 formed by the composite fine dots 210 can be more clearly presented on the first base paper 400, so as to further enhance the beauty of the printed paper.

[0087] However, considering that in this embodiment, printing and compounding are performed simultaneously, in order to form an indentation on the original thickness of the base paper, the pressing between the two pattern rollers requires a greater pressure than the traditional pre-pressing pattern. At this time, if the compound fine point 210 adopts a larger height, it will cause excessive wear and even breakage of the compound fine point 210.

[0088] To this end, in this embodiment, on the basis of the spacing H between the pressing surface of the printing boss 110 and the roller surface of the second flower roller 200 being 0.08-0.28 mm, the height of the composite fine point 210 is controlled within the range of 0.06 mm-0.25 mm, preferably 0.10 mm-0.20 mm. For example, 0.13 mm, 0.17 mm, 0.19 mm, etc. On the one hand, the clarity of the indentation can be guaranteed, and on the other hand, it is conducive to extending the service life of the composite fine point 210. Specifically in this embodiment, the first base paper 400 and the second base paper 500 are both two-layer base papers, and the height of the composite fine point 210 protruding from the roller surface of the second flower roller 200 is preferably about 0.15 mm, for example, 0.14 mm, 0.15 mm, 0.16 mm, etc. In other words, in this embodiment, there is no excessive requirement for the clarity of the second indentation 510 presented on the first base paper 400. However, when 2-8 sheets of base paper are used for compounding, the second indentation 510 can also be presented on the first base paper 400 .

[0089] In some embodiments, in order to reduce the friction loss of the compound fine dots 210, the first flower roller 100 and the second flower roller 200 use different diameters, so that the compound fine dots 210 at different positions are squeezed and matched with the printing boss 110 in turn, thereby effectively extending the service life of the compound fine dots 210.

[0090] Meanwhile, the hardness of the printed boss 110 and the composite fine point 210 is 50-70HRC. The selection of the hardness is to ensure that the printed boss 110 and the composite fine point 210 have a certain strength to meet the requirements of pressing and compounding, and to prevent the printed boss 110 and the composite fine point 210 from being easily cracked due to excessive hardness.

[0091] Furthermore, since the composite fine point 210 is alternately extruded and matched with the printing boss 110, in order to ensure the synchronization of the wear of the composite fine point 210 and the printing boss 110, the hardness of the printing boss 110 can be slightly greater than that of the composite fine point 210. Preferably, the hardness of the printing boss 110 is controlled within the range of 55-65HRC, and the hardness of the composite fine point 210 is controlled within the range of 50-60HRC.

[0092] In some embodiments, since the friction loss of the composite fine point 210 is effectively controlled, the composite fine point 210 can be made smaller, and its pressing area can be less than 0.1mm. 2 , for example, 0.02mm 2 , 0.05mm 2 , 0.07mm 2 、0.09mm 2etc. The composite fine dots 210 of smaller size can be outlined more densely in the printing pattern area formed by the printing boss 110, which is equivalent to filling more fine dots in the printing pattern area, and can also be understood as forming more "pixel points", thereby effectively improving the resolution of the printing pattern, making the printing pattern look more realistic and clear. However, if the fine dots are filled too densely, visual fatigue will occur during observation, and the printing pattern will feel unclear; in addition, if the fine dots are filled too densely, that is, the spacing between adjacent composite fine dots 210 is too small, it will be unfavorable for the formation of the second interlaced layer 620. In particular, for some kitchen and bathroom papers with coarse fibers, at this time, if the spacing between adjacent composite fine dots 210 is too small, it is difficult for the base paper to be squeezed into the spacing, which will affect the formation of the second interlaced layer 620. Therefore, in this embodiment, the gap between adjacent composite fine dots 210 is controlled within the range of 0.05-0.5mm, for example, 0.08mm, 0.14mm, 0.22mm, 0.35mm, 0.45mm, etc. It is preferably 0.15mm-0.3mm, for example, 0.18mm, 0.25mm, etc. In this embodiment, by reasonably controlling the size and spacing of the composite fine dots 210, the clarity of the printed pattern can be ensured, and the formation of the second interwoven layer 620 will not be affected, so as to ensure the firmness of the composite between the base papers.

[0093] Preferably, the composite fine point 210 is a columnar structure as a whole, and the pressing surface of the composite fine point 210 is a square structure. The length and width of the square pressing surface are both 0.1-0.3 mm, for example, 0.12 mm, 0.18 mm, 0.26 mm, etc. At the same time, the spacing between adjacent composite fine points 210 is controlled within the range of 0.08-0.25 mm, for example, 0.12 mm, 0.18 mm, 0.23 mm, etc. Compared with the traditional spherical pressing surface, since the square pressing surface is a plane, the pressing force on the base paper in the pressing area of ​​the entire pressing surface is more uniform, which is conducive to ensuring the composite effect.

[0094] Specifically in this embodiment, the height of the composite fine point 210 is 0.2 mm, and the spacing between adjacent composite fine points 210 is 0.15 mm. The lamination surface of the composite fine point 210 is a 0.2 mm*0.2 mm square structure as a whole. At the same time, in order to prevent the corners of the square lamination surface from scratching the base paper, the corners of the square lamination surface can be rounded.

[0095] refer to Figure 4As shown, as another implementation of a composite embossing roller group of this embodiment, it includes a pre-embossing roller group 300 and a composite roller group consisting of the above-mentioned first embossing roller 100 and the second embossing roller 200. Among them, the pre-embossing roller group 300 can be provided with one group, which is used to pre-press the first base paper 400 or the second base paper 500. The pre-embossing roller group 300 can also be provided with two groups, which are respectively used to pre-press the first base paper 400 and the second base paper 500 to form a third indentation on each base paper.

[0096] Specifically, the pre-embossing roller group 300 includes a third pattern roller and a rubber roller that abut against each other, and a plurality of pre-printing protrusions are formed on the roller surface of the third pattern roller. The pre-printing protrusions can be arranged in a certain pattern shape to enrich the pattern shape of the composite paper and enhance its beauty. At this time, in order to prevent the pattern pre-embossed by the pre-printing protrusion from being re-embossed and destroyed during the later composite process, the pattern formed by the pre-printing protrusion on the base paper should be staggered with the pattern formed by the printing boss 110.

[0097] Of course, the above-mentioned pre-printed protrusions may not form patterns of a certain shape. That is, the pre-printed protrusions are not intended to form patterns with a certain pattern on the base paper, but only to form a series of "concave points" on the base paper to increase the feel and water absorption of the composite paper. At this time, there is no need to consider the misalignment relationship between the "concave points" and the pattern formed by the printing boss 110. It is only necessary to ensure that the height of the printing boss 110 is greater than the height of the pre-printed protrusions, so that the "concave points" pre-formed on the base paper are destroyed during the composite pressing of the combined printing roller group, and new indentations can be formed. However, no matter which of the above-mentioned structural forms the pre-printed protrusions adopt, the mutual cooperation formed by the third flower roller and the rubber roller will inevitably make the thickness of the base paper thicker. Therefore, it can be applied to the production of some printed paper products that do not have strict requirements on thickness.

[0098] In some embodiments, in order to control the thickness of the paper within an acceptable range as much as possible, the height of the pre-printed protrusion should be less than the height of the printed boss 110. The height of the pre-printed protrusion is preferably 0.5-2.0 mm, such as 0.6 mm, 1.3 mm, 1.7 mm, etc. The height of the printed boss 110 is 0.8-2.5 mm to meet the requirements of some kitchen paper and toilet paper for deeper embossing, such as 1.1 mm, 1.6 mm, 2.3 mm, etc.

[0099] A composite printing roller group of this embodiment can simultaneously complete the printing and compounding operations between the base papers by using the cooperation of two flower rollers, and can obtain printed paper products with printed patterns without pre-printing, which ensures the beauty of the paper products without excessively increasing the thickness of the paper products. In addition, by controlling the distance between the top of the printing boss 110 and the roller surface of the second flower roller 200, so that the height of the composite fine point 210 protruding from the roller surface of the second flower roller 200 does not exceed 0.2mm, the composite area between the base papers can be greatly increased, and the firmness of the composite between the base papers can be ensured; at the same time, the risk of excessive wear or even breakage of the composite fine point 210 caused by the large pressing force required for printing can be eliminated.

[0100] refer to Figure 5 , Figure 6 As shown, this embodiment also provides a printed paper product, including a first base paper 400 and a second base paper 500 which are mutually layered, and the first base paper 400 and the second base paper 500 are respectively formed with a plurality of first indentations 410 and a plurality of second indentations 510 on their opposite surfaces under the mechanical pressing of the same roller group. Among them, the plurality of first indentations 410 can form at least one printed pattern, and each first indentation 410 is filled with a plurality of densely distributed second indentations 510. At the same time, a first interlaced layer 610 is formed at the junction of the first indentation 410 and the second indentation 510, so that the first base paper 400 and the second base paper 500 are connected together.

[0101] For the convenience of the following description, the surfaces of the first base paper 400 and the second base paper 500 that are close to each other are defined as the inner surfaces of the respective base papers, and the surfaces that are away from each other are defined as the outer surfaces of the respective base papers.

[0102] like Figure 5 As shown, when the printed paper product is observed from the outer surface of the first base paper 400, in addition to being able to see the pattern formed by the first indentation 410, the dense second indentations 510 can also be seen through the first indentation 410. At the same time, since the second indentations 510 are distributed at the bottom of the first indentation 410, and the area of ​​the second indentation 510 is much smaller than the first indentation 410. Therefore, when the printed paper product is observed from the outer surface of the first base paper 400, a number of small dots can be presented at the bottom of the first indentation 410, which not only makes the first indentation 410 clearer, but also presents a stronger three-dimensional effect. When the printed paper product is observed from the outer surface of the second base paper 500, the pattern formed by the dense second indentations 510 can also be seen. The pattern is actually obtained by outlining the second indentations 510 along the bottom of the first indentation 410.

[0103] Furthermore, the first base paper 400 and the second base paper 500 also form a second interlaced layer 620 at the bottom of the first indentation 410 and in the area other than the second indentation 510. That is, the second base paper 500 and the first base paper 400 in the area of ​​the first indentation 410 are in a mutually laminated state, so that the composite of the two is more solid. At the same time, when the first base paper 400 and the second base paper 500 are not pre-pressed, the parts of the printed paper product in the area other than the first indentation 410 are in a mutually laminated state. That is to say, the thickness of the printed paper product at this time is basically the same as the thickness when the first base paper 400 and the second base paper 500 are overlapped with each other.

[0104] In order to further improve the aesthetics of printed paper products, the first base paper 400 and the second base paper 500 can be pre-pressed, that is, before the first base paper 400 and the second base paper 500 are co-extruded and laminated, a third indentation can be formed on the first base paper 400 in advance. The third indentation can form a pattern with a certain shape; or it can not form a pattern with a certain shape, but only present a series of "concave points" on the base paper; or it can be a combination of "concave points" and patterns, that is, part of the third indentation forms a pattern, and part of the third indentation forms dense "concave points".

[0105] Of course, in order to ensure the integrity of the pattern, the pattern formed by the pre-printing needs to be staggered with the pattern formed by the first indentation 410. At the same time, in order not to affect the overall thickness of the printed paper as much as possible, the pressing depth of the third indentation can be less than the pressing depth of the first indentation 410.

[0106] refer to Figure 7 As shown, in some embodiments, the third impression is a series of concave points, and the concave points fill the entire area of ​​the base paper surface other than the first indentation 410 .

[0107] refer to Figure 8 As shown, in some embodiments, the third impression is a series of concave points, and the concave points are not filled in the entire area of ​​the base paper surface other than the first indentation 410, but leave a boundary between the area where the first indentation 410 forms the printed pattern, so that the printed pattern is more prominent and has a stronger three-dimensional effect. Of course, the third indentation can also be pre-formed on the second base paper 500.

[0108] A printed paper product of the present embodiment can form a printed pattern with a certain shape on the surface of the first base paper 400 through the first indentation 410, and the shape of the second indentation 510 can be presented on the first base paper 400 through the first indentation 410, which can effectively enrich the beauty of the paper product and improve the clarity of the printed pattern; at the same time, the parts between the first base paper 400 and the second base paper 500 in the first indentation area 410 are in a mutually laminated state, which can effectively ensure the laminated area; and the parts in the non-first indentation 410 area are in a mutually fitted state, avoiding the existence of an air layer, which is beneficial to ensure the thickness of the paper after compounding.

[0109] In addition, it should be noted that, from the attached drawings, although the existence of the first interlaced layer 610 and the second interlaced layer 620 can be clearly seen. However, the attached drawings are only for the convenience of understanding the solution of the present invention, which does not mean that the first interlaced layer 610 and the second interlaced layer 620 will definitely be detected. It can be understood that the existence of the first interlaced layer 610 and the second interlaced layer 620 is to compound the base paper. Therefore, when the base papers of the compounded printed paper products are separated, in the corresponding area, it can be felt that the base papers are mutually adhered, which can be regarded as the existence of the first interlaced layer 610 and the second interlaced layer 620.

[0110] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A composite embossing method, characterized in that: The roller group used comprises a first pattern roller (100) and a second pattern roller (200); a plurality of printing bosses (110) are arranged on the roller surface of the first pattern roller (100); and a plurality of composite fine dots (210) are densely distributed at intervals on the roller surface of the second pattern roller (200); During processing, the distance H between the top of the printing boss (110) and the roller surface of the second pattern roller (200) is controlled to be smaller than the overlapping thickness of the base paper that is jointly introduced; the first base paper (400) and the second base paper (500) are jointly introduced into the gap between the first pattern roller (100) and the second pattern roller (200), and the first base paper (400) and the second base paper (500) are squeezed by the first pattern roller (100) and the second pattern roller (200), and the printing and laminating work is completed at the same time; The printing boss (110) is pressed on the surface of the first base paper (400) to form at least one printing pattern composed of a plurality of first indentations (410); the composite fine dots (210) corresponding to the printing boss (110) are pressed on the surface of the second base paper (500) to form a plurality of second indentations (510); and a first interlaced layer (610) is pressed and formed in the area where the bottom of the first indentation (410) overlaps with the second indentation (510).

2. A composite embossing method according to claim 1, characterized in that: A second interlaced layer (620) is formed by pressing in the non-overlapping area between the bottom of the first indentation (410) and the second indentation (510).

3. A composite embossing method according to claim 2, characterized in that: The height of the composite fine dots (210) is greater than the thickness of the second base paper (500), so that the second indentation (510) formed by the composite fine dots (210) can be more clearly presented on the first base paper (400).

4. A composite embossing method according to claim 1, characterized in that: The height of the composite fine point (210) is 0.05-0.2 mm.

5. A composite embossing method according to any one of claims 1 to 4, characterized in that: The first base paper (400) and / or the second base paper (500) are pre-pressed with a plurality of third indentations; the plurality of third indentations form a printed pattern or concave dots having a certain shape.

6. A composite embossing method according to claim 5, characterized in that: The pressing depth of the third indentation is less than the pressing depth of the first indentation (410), and when the third indentation is in the area of ​​the printing boss (110), it can be further pressed and composited on the first indentation (410).

7. A composite printing roller set, comprising a first pattern roller (100) and a second pattern roller (200) abutting against each other, wherein a plurality of printing bosses (110) are formed on the roller surface of the first pattern roller (100), characterized in that: The roller surface of the second pattern roller (200) is densely distributed with a plurality of composite fine dots (210); wherein: The spacing H between the top of the printing boss (110) and the roller surface of the second flower roller (200) is 0.08-0.28 mm, so that a first pressing area is formed between the printing boss (110) and the composite fine dots (210), and the first pressing area forms fine dots on the paper and fills the corresponding texture of the printing boss (110); a second pressing area is formed between the printing boss (110) and the roller surface of the second flower roller (200).

8. The composite printing roller assembly according to claim 7, characterized in that: The height of the composite fine point (210) protruding from the roller surface of the second pattern roller (200) is 0.10mm-0.25mm; the pressing area of ​​the composite fine point (210) is less than 0.1mm 2 , and the gap between adjacent composite fine points (210) is 0.05-0.5mm.

9. A composite printing roller assembly according to claim 7 or 8, characterized in that: It also includes at least one pre-embossing roller group (300) consisting of a third pattern roller and a rubber roller, wherein the third pattern roller is provided with a plurality of pre-printing protrusions; wherein the pre-printing protrusions form a printing pattern with a certain shape, or a series of convex points, or a combination of the printing pattern and the convex points.

10. The composite printing roller assembly according to claim 9, characterized in that: The height of the pre-printing protrusion is smaller than the height of the printing boss (110).

11. The composite printing roller assembly according to claim 10, characterized in that: The height of the printing boss (110) is 0.8-2.5 mm; the height of the pre-printing protrusion is 0.5-2.0 mm.

12. A composite printing roller set, comprising a first pattern roller (100) and a second pattern roller (200) abutting against each other, wherein a plurality of printing bosses (110) are provided on the roller surface of the first pattern roller (100), characterized in that: The roller surface of the second pattern roller (200) is densely distributed with a plurality of composite fine dots (210); wherein: A first pressing area is formed between the printing boss (110) and the composite fine dots (210), and the first pressing area forms fine dots on the paper and fills the texture corresponding to the printing boss (110); a second pressing area is formed between the printing boss (110) and the roller surface of the second flower roller (200); and the height of the composite fine dots (210) protruding from the roller surface of the second flower roller (200) is 0.08-0.28 mm.

13. A printed paper product, comprising a first base paper (400) and a second base paper (500) laminated to each other, characterized in that: The first base paper (400) and the second base paper (500) are respectively formed with a first indentation (410) and a second indentation (510) on their opposite surfaces under mechanical pressing by the same roller group; wherein: The densely distributed second indentations (510) are filled in the area of ​​the first indentations (410), and a first interlaced layer (610) is formed in the overlapping area of ​​the two indentations.

14. A printed paper product according to claim 13, characterized in that: A second interlaced layer (620) is formed in a non-overlapping region between the bottom of the first indentation (410) and the second indentation (510).

15. A printed paper product according to claim 13, characterized in that: The first base paper (400) and the second base paper (500) are partially laminated in the first indentation (410) region; the portions in the non-first indentation (410) region are in contact with each other; and the depths of the first indentation (410) and the second indentation (510) do not exceed the thickness of the respective base papers.

16. A printed paper product according to claim 13, characterized in that: A third impression is formed on the first base paper (400) and / or the second base paper (500), and the area of ​​the third impression is larger than the area of ​​the second impression (510); the third impression forms a printed pattern with a certain shape, or a series of concave dots, or a combination of the printed pattern and concave dots.

17. A printed paper product according to any one of claims 13 to 16, characterized in that: The third impression is a series of concave points, and the concave points fill the entire area of ​​the base paper surface other than the first indentation (410), or a boundary is left between the concave points and the area where the first indentation (410) forms a printed pattern.

Images