阅读说明：本技术 一种压纹双色艺术纸的生产方法 (Production method of embossed double-color art paper ) 是由 周大仕 车朝晖 于彦凤 李甲年 于 2020-05-22 设计创作，主要内容包括：本发明提供一种压纹双色艺术纸的生产方法,所述压纹双色艺术纸的生产方法包括以下步骤：(1)染色固色：将纸浆、染料、固色剂和湿强剂混合,进行染色固色；(2)一段烘缸干燥：将染色固色后的纸浆上网成形、压榨脱水后,进行一段烘缸干燥,得到湿纸页；(3)压纹处理：将一段烘缸干燥后得到的湿纸页在纸机内部进行压纹处理；(4)二段烘缸干燥：将压纹处理后的纸页进行二段烘缸干燥,得到所述压纹双色艺术纸。所述压纹双色艺术纸的生产方法解决了传统的机外压纹存在的缺陷,将需要印刷后对位压纹才能形成的双色压纹艺术纸在机内通过控制纸页的染色及压纹工艺,在纸机内一次形成颜色深浅变化、纹路深浅变化的艺术效果。(The invention provides a production method of embossed double-color art paper, which comprises the following steps: (1) dyeing and fixing color: mixing paper pulp, dye, a color fixing agent and a wet strength agent, and dyeing and fixing color; (2) drying in a first-stage drying cylinder: after the paper pulp after dyeing and color fixing is formed on a net and is pressed and dehydrated, drying the paper pulp by a first section of drying cylinder to obtain wet paper sheets; (3) embossing treatment: carrying out embossing treatment on the wet paper obtained after drying the first section of drying cylinder in the paper machine; (4) drying in a second-stage drying cylinder: and drying the embossed paper sheet by a two-stage dryer to obtain the embossed two-color art paper. The production method of the embossed double-color art paper solves the defects of the traditional external embossing, and the double-color embossed art paper which can be formed only by the alignment embossing after printing is subjected to dyeing and embossing processes of paper sheets in a machine, so that the art effects of color shade change and grain shade change are formed in the paper machine at one time.)

1. The production method of the embossed double-color art paper is characterized by comprising the following steps of:

(1) dyeing and fixing color: mixing paper pulp, dye, a color fixing agent and a wet strength agent, and dyeing and fixing color;

(2) drying in a first-stage drying cylinder: after the paper pulp after dyeing and color fixing is formed on a net and is pressed and dehydrated, drying the paper pulp by a first section of drying cylinder to obtain wet paper sheets;

(3) embossing treatment: carrying out embossing treatment on the wet paper obtained after drying the first section of drying cylinder in the paper machine;

(4) drying in a second-stage drying cylinder: and drying the embossed paper sheet by a two-stage dryer to obtain the embossed two-color art paper.

2. The method for producing embossed two-color art paper according to claim 1, wherein the preparation raw material of the pulp of the step (1) comprises softwood pulp and hardwood pulp;

preferably, the raw materials for preparing the paper pulp comprise the following components in percentage by mass, with the mass of the raw materials for preparing the paper pulp being 100%: 20-80% of softwood pulp and 20-80% of hardwood pulp.

3. The method for producing embossed two-color art paper according to claim 1 or 2, wherein the pulp of the step (1) is prepared by: pulping the softwood pulp and the hardwood pulp, and then mixing and pulping to obtain the paper pulp;

preferably, the beating degree of the pulp in step (1) is 30-40 ° SR;

preferably, the preparation raw material of the paper pulp in the step (1) also comprises other pulp;

preferably, the other pulp includes any one of waste paper pulp, reed pulp, bagasse pulp, or bamboo pulp, or a combination of at least two thereof.

4. The method for producing embossed two-color art paper according to any one of claims 1 to 3, wherein the dye is added in the step (1) in an amount of 0.1 to 2.0% based on the total absolute dry fiber amount of the pulp;

preferably, the fixing agent is added in the step (1) in an amount of 0.1-2.0% of the total absolute dry fiber amount of the pulp;

preferably, the fixing agent of step (1) is a cationic fixing agent;

preferably, the wet strength agent in the step (1) is added in an amount of 0.5-2.0% of the total absolute dry fiber amount of the pulp;

preferably, the wet strength agent of step (1) is a PAE wet strength agent.

5. The method for producing embossed two-color art paper according to any one of claims 1 to 4, wherein the step (1) of dyeing and fixing comprises the following specific steps: firstly, mixing paper pulp and dye for dyeing, then adding a color fixing agent for color fixing, and finally adding a wet strength agent and a sizing agent for mixing;

preferably, the dyeing and fixing in step (1) comprises the following specific steps: firstly, mixing paper pulp and dye for 20-40min for dyeing, then adding a color fixing agent for mixing for 5-10min for color fixing, and finally adding a wet strength agent and a sizing agent for mixing for 5-10 min.

6. The method for producing embossed two-color art paper according to any one of claims 1 to 5, wherein the step (2) of forming the upper web comprises the following specific steps: feeding the dyed and color-fixed paper pulp to a net, forming and dehydrating the paper pulp through a net part to form wet paper sheets;

preferably, the streaming internet surfing specifically comprises the following steps: feeding the paper pulp subjected to dyeing and color fixation to a front net box through a pulp feeding system, and feeding pulp to the front net box for forming;

preferably, sizing agent is added during the slurry flow;

preferably, the sizing agent is added in an amount of 0.5 to 2.0% of the total oven dry fiber amount of the pulp;

preferably, the sizing agent is a neutral sizing agent AKD;

preferably, the sizing agent is added continuously;

preferably, the temperature of the primary drying cylinder in the step (2) is 60-100 ℃;

preferably, the wet paper sheet moisture content after the dryer drying of the first section in step (2) is 12 to 42 wt%.

7. The method for producing embossed two-color art paper according to any one of claims 1 to 6, wherein the step (3) paper machine is a single-wire paper machine and/or a multi-wire paper machine;

preferably, step (3) is performed by providing an embossing unit inside the paper machine, the embossing unit comprising: the embossing device comprises a transmission system, a pressurizing system, an embossing roller with concave-convex lines and an embossing bottom roller;

preferably, the pressurization mode of the pressurization system adopts hydraulic pressurization and/or pneumatic pressurization;

preferably, the embossing bottom roller adopts a rubber roller and/or a polyurethane roller;

preferably, the embossing base roller has a shore hardness of 98A or more;

preferably, the embossing line pressure of the embossing process of step (3) is 30-90 kN/m.

8. The method of producing embossed two-color art paper according to any one of claims 1 to 7, wherein the temperature of the dryer drying in step (4) is 90 to 110 ℃.

9. The method of producing embossed two-color art paper according to any one of claims 1 to 8, further comprising the step (5) of surface sizing after the dryer drying of the dryer in the step (4): coating the surface sizing solution on the embossed double-color art paper obtained in the step (4);

preferably, the mass concentration of the surface sizing liquid is 3.0-5.0%;

preferably, the surface sizing solution is an oxidized modified starch solution;

preferably, the step (5) further comprises a drying treatment after surface sizing, wherein the drying temperature is 60-110 ℃;

preferably, the drying treatment after surface sizing also comprises finishing reeling.

10. The method for producing embossed two-color art paper according to any one of claims 1 to 9, wherein the method for producing embossed two-color art paper comprises the steps of:

(a) and (3) crushing the slurry: pulping the pulp sheets of softwood pulp and hardwood pulp in a pulper;

(b) pulping: mixing and pulping softwood pulp accounting for 20-80% of the total pulp amount and hardwood pulp accounting for 20-80% of the total pulp amount to obtain paper pulp with a beating degree of 30-40 DEG SR;

(c) dyeing and fixing color: firstly, mixing paper pulp and dye accounting for 0.1-2.0% of the total oven dry fiber for 20-40min for dyeing, then adding a color fixing agent accounting for 0.1-2.0% of the total oven dry fiber for mixing for 5-10min for color fixing, and finally adding a wet strength agent accounting for 0.5-2.0% of the total oven dry fiber for mixing for 5-10 min;

(d) flow-feeding, wire-feeding, forming and dewatering: feeding the dyed and color-fixed pulp to a head box through a pipeline for pulp feeding, and continuously adding a sizing agent accounting for 0.5-2.0% of the total absolute dry fiber amount in the pipeline while feeding the pulp; the slurry is formed by the front net box; forming and dehydrating the paper pulp fed to the wire section to form a wet paper sheet, and pressing the wet paper sheet in a pressing section for further dehydration;

(e) drying in a first-stage drying cylinder: drying the wet paper sheet obtained after squeezing by a first-stage drying cylinder at the temperature of 60-100 ℃ to obtain a paper sheet with the water content of 12-42 wt%;

(f) embossing treatment: carrying out embossing treatment on the paper sheet obtained after drying in the first-section drying cylinder in the paper machine, wherein the line pressure of the embossing treatment is 30-90 kN/m;

(g) drying in a second-stage drying cylinder: drying the embossed paper sheet by a two-stage dryer at the temperature of 90-110 ℃ to obtain the embossed two-color art paper;

(h) surface sizing: coating the embossed two-color art paper by using surface sizing solution with the mass concentration of 3.0-5.0%;

(i) and (3) drying: drying the embossed two-color art paper subjected to surface sizing at 60-110 ℃;

(j) coiling: and obtaining a finished product from the dried embossed two-color art paper roll.

Technical Field

The invention belongs to the field of art paper production, and particularly relates to a production method of embossed double-color art paper.

Background

Colored embossed paper has been a popular type of art paper among packaging designers. The art paper is different from other common paper types, such as offset paper, coated paper, light paper, newsprint, wrapping paper and the like, and the art paper needs to be processed into paper with rich colors and unique grains through special processing equipment and technology. The dyeing of the paper sheets is divided into two types of machine dyeing and machine dyeing, wherein the machine dyeing is that dye is added into a paper machine during the production of the paper sheets, the paper sheets are dyed into various colors in the paper machine, and the machine dyeing is that white (undyed) paper sheets are produced by the paper machine, and the paper sheets are dyed with colors in other gravure processing equipment or dipping processing equipment. The disadvantages of the external dyeing are that a processing procedure is added compared with the internal dyeing, and the flatness of the paper after the external dyeing is different from that of the paper from a paper machine, the uniformity of the color is poor, and the inside and outside of the paper industry have larger color difference. And sometimes, in order to thoroughly dip-dye the paper color, some auxiliary agents for helping the dye to permeate into the paper are added into the dye, and the auxiliary agents are not environment-friendly, and can be remained in the paper and are color paper sheets which are not environment-friendly.

Most of the paper sheets with various lines on the market are produced on a paper machine, and then various lines are pressed on the surface of the paper sheets by using a special embossing machine, namely, the paper sheets are embossed outside the machine, and the paper sheets which are dried by the paper machine are embossed outside the machine by using the special embossing machine. The color of the texture part of the color paper sheet embossed outside the machine does not change, namely, the colors of the texture high points and the texture low points of the embossed paper sheet are consistent, and no obvious color change exists. If the color of the embossed part is changed, a gravure printing roller corresponding to the texture of the embossing roller is needed, the texture on the embossing roller is printed on the paper by a paper sheet in a gravure mode, the color of the embossed texture part is deepened, and the position of the paper sheet printed with the color is subjected to counterpoint embossing to form the double-color embossed art paper. The method is complicated, and the alignment embossing has high precision required by equipment and high processing difficulty.

CN102433801A discloses a method for producing a colored parchment paper, which comprises controlling the pulp-web speed ratio of sizing on a paper machine to make the paper sheet form a paper sheet with poor evenness, adding a dye into the surface sizing liquid during surface sizing, immersing the dye into the paper sheet along with the surface sizing liquid, and when passing through a sizing press roller, the paper sheet is subjected to a large extrusion force at the position with pulp flocs, the dye and the surface sizing liquid are extruded, the color becomes light, the part without the pulp flocs is subjected to a small extrusion force of the surface sizing roller, the dye and the sizing liquid are large, and the color of the part is dark. This forms a sheet with alternating shade and shade color patterns. However, the colored patterns obtained by the production method are randomly formed and easily damage the surface of the paper, and the pressed lines are rigid, have no fixed line effect and are unnatural.

CN106120464A discloses a method for producing artistic anti-counterfeiting paper with semitransparent indentations, wherein the paper is produced by a paper machine, raw paper is added with SWP fibers and PE powder materials, then an external embossing machine is used for embossing, and the production of the artistic anti-counterfeiting paper with semitransparent indentations is completed by controlling the embossing temperature and pressure. Similarly, the paper sheet with the texture pressed by the method not only has damage to the surface of the paper sheet, but also the pressed texture is rigid and unnatural.

Therefore, it is desirable to develop a process that provides significant variation in sheet color and shade.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a method for producing embossed double-color art paper. The production method of the embossed double-color art paper solves the defects of the traditional external embossing, and the double-color embossed art paper which can be formed only by aligning and embossing after printing is formed in a paper machine at one time by controlling the dyeing and embossing processes of paper sheets, so that the artistic effects of color shade change and grain shade change appear on the surface of the paper sheets.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a method for producing embossed two-color art paper, which comprises the following steps:

(1) dyeing and fixing color: mixing paper pulp, dye, a color fixing agent and a wet strength agent, and dyeing and fixing color;

(2) drying in a first-stage drying cylinder: after the paper pulp after dyeing and color fixing is formed on a net and is pressed and dehydrated, drying the paper pulp by a first section of drying cylinder to obtain wet paper sheets;

(3) embossing treatment: carrying out embossing treatment on the wet paper obtained after drying the first section of drying cylinder in the paper machine;

(4) drying in a second-stage drying cylinder: and drying the embossed paper sheet by a two-stage dryer to obtain the embossed two-color art paper.

The production method of the embossed two-color art paper sequentially comprises the steps of size disintegration, dyeing and color fixation, net-laying forming, squeezing, first-stage drying cylinder drying, embossing treatment and second-stage drying cylinder drying. Wherein, the mode that first step directly adopts and directly dyes the fixation with paper pulp, dyestuff, fixing agent and wet strength agent mixture, and this kind of dyeing fixation mode is through the fixation effect of fixing agent again after the dyestuff fully dyes the paper pulp fibre, can make the cellulose of paper pulp fully dye, and the cohesion of cellulose and dyestuff molecule is higher, and the even dispersibility of dyestuff is good to improve the dyeing homogeneity and the colour fastness that obtain the page, and add the wet strength agent, with the intensity requirement of guaranteeing the subsequent processing page, and the intensity requirement of the page after the finished paper. Secondly, drying the paper pulp subjected to dyeing and color fixation in a first section of drying cylinder to obtain a paper sheet which is suitable for embossing and discoloring and contains certain moisture; and thirdly, carrying out embossing treatment on the paper sheet containing certain moisture obtained after drying the first-section drying cylinder in the paper machine, wherein the embossing procedure of the invention is moved from external embossing to the inside of the paper machine, and a step of carrying out embossing treatment in the paper machine is innovatively added between the drying of the first-section drying cylinder and the drying of the second-section drying cylinder.

Preferably, the preparation raw material of the pulp in the step (1) comprises softwood pulp and hardwood pulp.

Preferably, the raw materials for preparing the paper pulp comprise the following components in percentage by mass, with the mass of the raw materials for preparing the paper pulp being 100%: 20-80% of softwood pulp and 20-80% of hardwood pulp. According to the invention, softwood pulp and hardwood pulp are mixed in a proper proportion, so that the prepared embossed double-color art paper has certain mechanical strength; the cellulose content of the wood pulp is reasonably controlled, and the infiltration of the dye to the cellulose is facilitated.

The softwood pulp may be added in an amount of 20 to 80%, for example, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, etc., based on 100% by mass of the raw material for pulp production.

The hardwood pulp may be added in an amount of 20 to 80%, for example, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% or the like, based on 100% by mass of the raw material for pulp production.

Preferably, the pulp preparation method in the step (1) comprises the following steps: and (3) disintegrating the pulp of softwood pulp and hardwood pulp, and then mixing and pulping to obtain the paper pulp.

Preferably, the degree of beating of the pulp of step (1) is 30 to 40 ° SR, and may be, for example, 30 ° SR, 31 ° SR, 32 ° SR, 33 ° SR, 34 ° SR, 35 ° SR, 36 ° SR, 37 ° SR, 38 ° SR, 39 ° SR, 40 ° SR, etc.

Preferably, the preparation raw material of the pulp in the step (1) also comprises other pulp.

Preferably, the other pulp includes any one of waste paper pulp, reed pulp, bagasse pulp, or bamboo pulp, or a combination of at least two thereof. The invention can add other pulp in a certain proportion into the pulp under the condition of not influencing the dyeing and embossing of paper sheets.

Preferably, the dye is added in the step (1) in an amount of 0.1 to 2.0% based on the total absolute dry fiber amount of the pulp, for example, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, etc.

Preferably, the fixing agent is added in the step (1) in an amount of 0.1-2.0% of the total oven dry fiber amount of the pulp, and for example, may be 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, etc.

The direct dye is adopted to dye the pulp during dyeing and color fixing, the dye amount is different according to the colors of different paper sheets, the dyed pulp needs to be subjected to color fixing after the dyeing is carried out, and the color fixing agent is added into the pulp to fix the dye after the dyeing so that the dye is firmly attached to the paper pulp fibers.

Preferably, the fixing agent of step (1) is a cationic fixing agent. Both the dye and the cellulose of the pulp carry anionic charges, and the cationic fixing agent carries cationic charges. Thus, the cationic fixing agent acts like a bridge therein, tightly binding the dye and the cellulose together. And the color fixing agent reacts with hydrophilic groups in the dye to seal the dye, so that the anionic property of the dye is sealed, the color fixing purpose is achieved, the water immersion color fastness of the paper is improved, the paper does not fade even after being placed in water for a long time, and the pollution to the environment is reduced.

Preferably, the fixing agent is LS-1 type paper fixing agent produced by Hangzhou green auxiliary agent research institute.

Preferably, the wet strength agent of step (1) is added in an amount of 0.5 to 2.0% of the total oven dry fiber amount of the pulp, for example, it may be 0.5%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, etc.

Preferably, the wet strength agent of step (1) is a PAE wet strength agent.

Preferably, the dyeing and fixing in step (1) comprises the following specific steps: firstly, mixing paper pulp and dye for dyeing, then adding a color fixing agent for color fixing, and finally adding a wet strength agent and a sizing agent for mixing.

Preferably, the dyeing and fixing in step (1) comprises the following specific steps: firstly, mixing paper pulp and dye for 20-40min (for example, 20min, 25min, 30min, 35min, 40min and the like) to dye, then adding a color fixing agent to mix for 5-10min (for example, 5min, 6min, 7min, 8min, 9min, 10min and the like) to fix color, and finally adding a wet strength agent to mix for 5-10min (for example, 5min, 6min, 7min, 8min, 9min, 10min and the like).

Preferably, the step (2) of forming the upper wire comprises the following specific steps: feeding the dyed and color-fixed paper pulp to a net, forming and dehydrating the paper pulp through a net part to form wet paper sheets;

preferably, the streaming internet surfing specifically comprises the following steps: feeding the paper pulp subjected to dyeing and color fixation to a front net box through a pulp feeding system, and feeding pulp to the front net box for forming;

preferably, sizing agent is added during the slurry flow;

preferably, the sizing agent is added in an amount of 0.5 to 2.0% of the total oven dry fiber amount of the pulp, and may be, for example, 0.5%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, etc.

Preferably, the sizing agent is a neutral sizing agent AKD.

Preferably, the sizing agent is added continuously.

Preferably, the temperature of the primary drying in step (2) is 60-100 deg.C, such as 60 deg.C, 70 deg.C, 80 deg.C, 90 deg.C, 100 deg.C, etc.

Preferably, the wet paper sheet moisture content after the dryer drying of the first section of step (2) is 12-42 wt%, and may be, for example, 12 wt%, 14 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 24 wt%, 26 wt%, 28 wt%, 30 wt%, 32 wt%, 34 wt%, 36 wt%, 38 wt%, 40 wt%, 42 wt%, etc. Because the embossing treatment is required in the step (3), the moisture of the paper sheet is required to be kept at 12-42 wt% during the embossing, the moisture content of the wet paper sheet dried by the first section of drying cylinder is only 12-42 wt%, the change of the fiber density can be formed after the embossing treatment under the condition that the paper sheet contains a certain moisture, the color of the part of the paper sheet with large fiber density is ensured to be dark, and the embossed two-color art paper with different color shades is formed. When the water content of the paper sheet is less than 12 wt%, the color change effect of the paper sheet is poor and is not obvious during embossing. When the water content of the paper sheet is more than 42 wt%, the arrangement state of the fibers in the wet paper sheet is destroyed and the paper sheet is locally crushed to cause paper defects if the wet paper sheet is not drained smoothly.

Preferably, the paper machine of step (3) is a single-wire machine and/or a multi-wire machine.

In the invention, the paper sheet produced by the single-wire paper machine is a layer of paper sheet, and the proportion of the whole fibers of the paper sheet is the same.

In the invention, the same pulp fiber proportion can be adopted by each layer of paper sheets produced by the multi-wire paper machine; other pulp (any one or combination of at least two of waste paper pulp, reed pulp, bagasse pulp or bamboo pulp) can be adopted in the inner layer, and mixed pulp of softwood pulp and hardwood pulp can be adopted in the front and back surface layers.

Preferably, the multi-wire machine is a four-cylinder machine.

Preferably, step (3) is performed by providing an embossing unit inside the paper machine, the embossing unit comprising: the embossing device comprises a transmission system, a pressurizing system, an embossing roller with concave-convex lines and an embossing bottom roller.

Preferably, the pressurization mode of the pressurization system adopts hydraulic pressurization and/or pneumatic pressurization.

In the invention, the embossing roller with concave-convex lines is processed by a professional embossing roller engraving manufacturer according to the line requirements of paper sheets.

Preferably, the embossing bottom roller is a rubber roller and/or a polyurethane roller.

Preferably, the embossing base roller has a shore hardness of 98A or more, and may be, for example, 98A, 99A, 100A, 101A, 102A, 103A, 104A, 105A, or the like.

Preferably, the embossing line pressure of the embossing process of step (3) is 30-90kN/m, and may be, for example, 30kN/m, 40kN/m, 50kN/m, 60kN/m, 70kN/m, 80kN/m, 90kN/m, or the like.

Preferably, the temperature of the dryer in the second stage of step (4) is 90-110 deg.C, such as 90 deg.C, 95 deg.C, 100 deg.C, 105 deg.C, 110 deg.C, etc.

Preferably, the method further comprises the step (5) of surface sizing after the drying of the second dryer in the step (4): and (4) coating the surface sizing solution on the embossed double-color art paper obtained in the step (4).

Preferably, the surface sizing solution has a mass concentration of 3.0 to 5.0%, and may be, for example, 3.0%, 3.2%, 3.4%, 3.6%, 3.8%, 4.0%, 4.2%, 4.4%, 4.6%, 4.8%, 5.0%, or the like.

Preferably, the surface sizing solution is an oxidized modified starch solution.

Preferably, the surface sizing in step (5) further comprises a drying treatment after the surface sizing, and the drying temperature is 60-110 ℃, for example, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 105 ℃, 110 ℃ and the like.

Preferably, the production method of the embossed two-color art paper comprises the following steps:

(a) and (3) crushing the slurry: pulping the pulp sheets of softwood pulp and hardwood pulp in a pulper;

(b) pulping: mixing and pulping softwood pulp accounting for 20-80% of the total pulp amount and hardwood pulp accounting for 20-80% of the total pulp amount to obtain paper pulp with a beating degree of 30-40 DEG SR;

(c) dyeing and fixing color: firstly, mixing paper pulp and dye accounting for 0.1-2.0% of the total oven dry fiber for 20-40min for dyeing, then adding a color fixing agent accounting for 0.1-2.0% of the total oven dry fiber for mixing for 5-10min for color fixing, and finally adding a wet strength agent accounting for 0.5-2.0% of the total oven dry fiber for mixing for 5-10 min;

(d) flow-feeding and net-surfing dehydration: feeding the dyed and color-fixed pulp to a head box through a pipeline for pulp feeding, and continuously adding a sizing agent accounting for 0.5-2.0% of the total absolute dry fiber amount in the pipeline while feeding the pulp; the slurry is formed by the front net box; forming and dehydrating the paper pulp fed to the wire section to form a wet paper sheet, and pressing the wet paper sheet in a pressing section for further dehydration;

(e) drying in a first-stage drying cylinder: drying the wet paper sheet obtained after dehydration by a first-stage drying cylinder at the temperature of 60-100 ℃ to obtain a paper sheet with the water content of 12-42 wt%;

(f) embossing treatment: carrying out embossing treatment on the paper sheet obtained after drying in the first-section drying cylinder in the paper machine, wherein the line pressure of the embossing treatment is 30-90 kN/m;

(g) drying in a second-stage drying cylinder: drying the embossed paper sheet by a two-stage dryer at the temperature of 90-110 ℃ to obtain the embossed two-color art paper;

(h) surface sizing: coating the embossed two-color art paper by using surface sizing solution with the mass concentration of 3.0-5.0%;

(i) and (3) drying: drying the embossed two-color art paper subjected to surface sizing at 60-110 ℃;

(j) coiling: and obtaining a finished product from the dried embossed two-color art paper roll.

Compared with the prior art, the invention has the following beneficial effects:

(1) the production method of the embossed double-color art paper solves the defects of the traditional external embossing, and the double-color embossed art paper which can be formed only by aligning embossing after printing is formed in a machine at one time by controlling the dyeing and embossing processes of paper sheets, so that the artistic effects of color shade change and grain shade change appear on the surface of the paper sheets;

(2) the embossed double-color art paper produced by the method can form concave-convex textures, the paper sheets at the concave parts are dark, the paper sheets at the convex parts are light, the color difference of the concave-convex textures is obvious, the brightness difference delta L is up to below-2, and the total color difference delta E is up to above 2.5.

Drawings

FIG. 1 is a flow chart of the production of embossed two-color art paper according to the present invention;

FIG. 2 is a grain diagram of a pale yellow dual-color ancient ceramic paper provided in example 1;

FIG. 3 is a grain diagram of the brown bicolor leather paper provided in example 2;

FIG. 4 is a grain diagram of the red two-color ancient plain paper provided in example 3;

FIG. 5 is a schematic view of the in-machine embosser machine of the present invention;

wherein, 1 is the embossing roller with concave-convex lines, 2 is the embossing bottom roller, 3 is the transmission system, and 4 is the pressurization system.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

The sources of the components in the following examples are as follows: the softwood pulp is Kalipp softwood pulp, the hardwood pulp is Ribose hardwood pulp, the color fixing agent is LS-1 type paper color fixing agent produced by Hangzhou green auxiliary agent research institute, the PAE wet strength agent is PAE produced by Ziboslingli chemical industry Limited, the oxidative modified starch is oxidative modified starch produced by Yanzhou Yanlai starch Limited, and the dye is direct dye purchased in the conventional market.

FIG. 1 is a production flow chart of the embossed two-color art paper, which is characterized in that after being disintegrated, pulp is sequentially subjected to pulping, dyeing and color fixing, flow feeding and web surfing, dehydration, drying in a first-stage drying cylinder, embossing treatment, drying in a second-stage drying cylinder, surface sizing and drying, and then the finished product is obtained by coiling and packaging.

FIG. 5 is a schematic view of the in-machine embosser machine of the present invention; wherein, 1 is the embossing roller with concave-convex lines, 2 is the embossing bottom roller, 3 is the transmission system, and 4 is the pressurization system. The device is arranged in the paper machine, the speed of the transmission system is matched with the speed of the paper machine, the transmission system drives the embossing roller to rotate, and the pressurizing system controls the pressure between the embossing roller with concave-convex grains and the embossing bottom roller to press the grains onto paper sheets.