Manufacturing process for restoring paper characteristics of Chengnen scroll paper

Abstract

The invention discloses a manufacturing process for restoring paper characteristics of Chengnen scroll paper. The manufacturing process comprises the following steps of (1) material selection, (2) drying in the shade, (3) soaking, (4) pressure application, (5) cooking, (6) bleaching, (7) beating, (8) pulping, (9) desanding, (10) pulp preparation, (11) paper fishing, (12) squeezing, (13) paper drying, (14) processing and (15) physicochemical index detection. The prepared paper integrates the advantages of the steps of material selection, beating, desanding, paper fishing and the like, so that the prepared paper is fine and smooth in fiber and good in integrity, and relatively high wet strength and relatively low anti-aging whiteness of the paper are ensured. According to the finally prepared finished product paper, the paper characteristics of the Chenxi scroll paper are greatly restored, the wet strength and the anti-aging whiteness are highly restored, the requirements of the Song dynasty calligraphy and painting paper on the uncooked and matured properties and the ink absorption property are met in the external performance, and the characteristics that the skin is like an egg membrane and the hardness is like jade are recarved.

Description

Technical Field

[0001] The invention relates to a production process for restoring the paper properties of Chengxintang paper. Background Art

[0002] Papermaking is one of the four great inventions of the Chinese nation, and paper is an important medium for the development of civilization and cultural inheritance. In the brilliant historical process of papermaking skills, various types of paper with unique characteristics have emerged. However, due to the changes of the times and history, many excellent papermaking techniques have not been passed down, and can often only be seen in cultural relics. The excellent characteristics of cultural relic paper have amazed the world, among which Chengxintang paper is the best quality. According to historical records, Chengxintang paper is "smooth as spring ice and dense as cocoon", "Shu paper is brittle and can not be eaten for a long time, and Yan paper is thin and can be eaten slowly". The first sentence shows that the surface of the paper is smooth and the texture is fine, and the second sentence shows that the paper wall is tough and thicker than Yan paper. From this, it is not difficult to see the high quality of Chengxintang paper.

[0003] Chengxintang paper is a rare paper for calligraphy and painting by many literati. Some people imitated Chengxintang paper, but the materials and craftsmanship were different and there was no unified standard. However, after describing the characteristics of Chengxintang paper in historical materials (such as: skin like egg membrane, hard like jade) and studying the originals that have been preserved (paper is rusty and has good ink absorption), Chengxintang paper has two nearly perfect characteristics, that is, high wet strength and low aging resistance whiteness. Therefore, restoring the characteristics of wet strength and aging resistance whiteness of Chengxintang paper is the research direction that the staff in this field want to study, which can enrich papermaking skills, promote the development of paper culture, and meet the needs of ancient book restoration. Summary of the invention

[0004] In view of the above-mentioned defects of the prior art, the object of the present invention is to provide a production process for restoring the paper properties of Chengxintang paper.

[0005] To solve the above problems, the technical solution of the present invention is: a production process for restoring the properties of Chengxintang paper, comprising the following steps: (1) Material selection: Select the bark of Pteris chinensis and Chu bark as the raw materials for making paper. Prepare 2 pieces of Pteris chinensis bark, select the bark of Pteris chinensis branches with a growth period of more than 3 years, peel it and cut it into sections of 90 cm; prepare 1 piece of Paper mulberry bark, select the flat bark of a 1-year-old Paper mulberry branch with a diameter of 3 cm, peel it and cut it into sections, the length of which is the same as that of the Pteris chinensis bark after processing; (2) Dry in the shade: Place the cut Pteris tannins and Paper mulberry bark in a cool place for later use; (3) Soaking: Soak the cut Pteris tannins and Paper mulberry bark in water for 24 hours and then take them out for later use; (4) Pressure: The soaked Phellodendron chinense bark and Paper mulberry bark are folded and turned over continuously, and after each folding and turning, a heavy object is used to press firmly from the top, and this process is repeated 100 times to obtain soft Phellodendron chinense bark and Paper mulberry bark; (5) Steaming: Put the soft Pteris tannins and Paper mulberry bark into an iron pot, add 4% of the dry pulp weight of soda ash for steaming, and gradually increase the temperature until it reaches 100 degrees Celsius. Keep the temperature for 4 hours and then cool naturally. After cooling, wash with water and sort manually. (6) Bleaching: The steamed and sorted Pteris chinensis bark and Paper mulberry bark are bleached with hydrogen peroxide and then washed; (7) Explain: Use a pounding machine to simulate the ancient rice pounding action to pound the bark of Pteris chinensis and the bark of Paper mulberry for 20 minutes. (8) Beating: The beaten Pteris tannin bark and Paper mulberry bark were mixed and placed in a pulping device, and the pulping device was used for 40 minutes to cut and stir the pulp to obtain a pulp with a beating degree of 32 degrees; (9) Sand removal: Adjust the pulp concentration to 5‰ and remove impurities through a desander and a round screen; (10) Slurry preparation: Add paper medicine to the slurry and stir evenly, then add Coptis chinensis insect-proof processing liquid and anti-mildew processing liquid; (11) Fishing paper: The paper scooping equipment is used for scooping paper, the scooping method is curtain hanging, and the thickness of single layer of paper is 23g; (12) Pressing: Use a 50T jack to squeeze the water out of the paper; (13) Drying paper: The temperature of the baking wall for drying paper is below 60℃, and the second layer is dried; (14) Processing: Finished paper is sized, polished and calendered; (15) Physical and chemical index testing.

[0006] Furthermore, the paper scooping equipment includes a high platform and a bamboo curtain platform. A baffle is provided at the upper front end of the high platform. The baffle is connected to a lifting rod for driving the up and down movement. A downstream plate is provided in the middle of the front end of the high platform. The bamboo curtain platform is located in the front and lower part of the downstream plate. The slurry is placed on the high platform, and multiple bamboo curtains are placed on the top of the bamboo curtain platform. The baffle of the high platform is opened to allow the slurry to be gradually spread on the bamboo curtain under the action of gravity.

[0007] Furthermore, step (2) is specifically as follows: evenly spread the cut Phellodendron chinense bark and Paper mulberry bark and place them on a bamboo drying rack that is well ventilated, avoids direct sunlight and has moderate humidity; lay a layer of pure cotton coarse cloth under the drying rack; gently turn the Phellodendron chinense bark and Paper mulberry bark every 2 hours to ensure that all parts of the Phellodendron chinense bark are evenly exposed to the wind; at the same time, place bamboo baskets filled with natural camphor wood blocks around the shade drying area, use the smell of the camphor wood to repel insects and prevent moths, and ensure that the Phellodendron chinense bark and Paper mulberry bark are not attacked by insects and ants during the shade drying process, until their moisture content is reduced to 15%, reaching a suitable state for standby use.

[0008] Furthermore, step (3) is specifically as follows: prepare two large ceramic vats, fill the vats with spring water in advance, carefully place the cut Pteris tannin bark and Paper mulberry bark into different ceramic vats respectively, and ensure that the bark is completely immersed in the water; cover the mouth of the vat with a layer of breathable fine yarn to prevent foreign matter from falling into it; then, add finely ground shell powder into the water, the particle size of the shell powder is less than 0.1 mm; at the same time, place a number of polished pebbles at the bottom of the vat to promote slight disturbance of the water flow; replace the water in the vat every 6 hours, and take it out after soaking for 24 hours.

[0009] Furthermore, step (4) is specifically as follows: a wooden pressure platform is used, the surface of the platform is flat and smooth and has good air permeability, the soaked cinnabar bark and paper mulberry bark are respectively spread on the platform, and the leather is continuously folded and turned over by using bamboo strips. After each folding and turning, a granite stone with a fine texture engraved on the surface is placed on the top of the leather. The weight of these stones is adjusted according to the state of the leather and the processing progress. The initial weight is 20 kg and gradually increases to 50 kg. During the pressure process, the placement of the leather is changed every 5 folding and turning to ensure that all parts of the leather are evenly pressurized. This operation is repeated 100 times until the cinnabar bark and paper mulberry bark are soft and tough.

[0010] Furthermore, in step (5), the temperature is gradually increased at a rate of 2 degrees Celsius per minute. During the heating process, the material in the pot is slowly stirred every 15 minutes using a stirring rod made of nanmu bamboo. The stirring speed is maintained at 10 revolutions per minute to ensure that the leather is heated evenly. When the temperature rises to 100 degrees Celsius, this temperature is maintained constant for 4 hours.

[0011] Furthermore, step (6) is specifically as follows: neatly stack the steamed and sorted Pteris tannins and Paper mulberry bark in a stirring container, prepare hydrogen peroxide for bleaching, and treat the hydrogen peroxide with ultraviolet light for 30 minutes in advance to enhance its activity; then, slowly inject hydrogen peroxide into the container to ensure that the hydrogen peroxide completely immerses the leather; then, install a set of devices that can generate weak ultrasonic waves above the container, turn on the ultrasonic waves to allow the hydrogen peroxide to penetrate and act more evenly between the leathers; during the bleaching process, use a glass stirring rod to gently stir the leather every 30 minutes, and keep the stirring speed at 5 revolutions per minute; after bleaching for 2 hours, stop the ultrasonic wave and stirring, and drain the hydrogen peroxide; then, use soft water at a temperature of 30 degrees Celsius to rinse the leather several times, and constantly turn the leather during the rinsing process to ensure that the residual hydrogen peroxide is completely removed, and rinse for 15 minutes each time, for a total of 3 times.

[0012] Furthermore, in step (7), the beating machine is stopped every 5 minutes, and the leather is turned over manually to ensure that all parts of the leather can be fully and evenly beaten.

[0013] Furthermore, in step (8), the Pteris tannin bark and the Paper mulberry bark are mixed and placed in a barrel of a pulping device. After the pulping device is started, the blade rotates at a speed of 1500 revolutions per minute to cut and stir the leather.

[0014] Furthermore, the inner wall of the barrel is provided with a plurality of tiny protrusions to enhance the friction and kneading effect on the leather material.

[0015] The beneficial effects of the present invention are as follows: the fibers of the prepared paper are relatively complete and delicate because of the combination of advantageous techniques in various steps such as material selection, beating and paper scooping. The paper is further improved in wet strength and reduced in aging resistance whiteness by combining paper mulberry fiber with eucalyptus ash fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the paper scooping device of the present invention; Figure 2 It is a structural schematic diagram of the bamboo curtain of the present invention.

[0017] As shown in the picture: 1—high platform, 2—bamboo curtain platform, 3—baffle, 4—lifting rod, 5—downstream board, 6—bamboo curtain. DETAILED DESCRIPTION

[0018] In order to more intuitively and completely understand the technical solution of the present invention, a non-limiting feature description is now provided as follows: A production process for restoring the properties of Chengxintang paper, comprising the following steps: (1) Material selection: Selecting celtis sinensis bark (bast fiber of celtis sinensis bark is the main raw material of Xuan paper craft, and the imitation paper of Chengxintang in Song Dynasty has a very high degree of adhesion with Xuan paper. The present invention selects celtis sinensis bark as one of the raw materials of this process to increase the soft, white and delicate characteristics of paper, but its toughness is slightly poor) and mulberry bark (the bast fiber of paper mulberry bark has high strength. Although pure paper mulberry bark paper has toughness, it is not soft enough. Paper mulberry bark is selected as one of the raw materials of this process to add its strong toughness) as the raw materials for making paper, preparing 2 parts of celtis sinensis bark, selecting the bark of celtis sinensis branches with a growth cycle of more than 3 years, peeling and cutting into sections of 90 cm; preparing 1 part of paper mulberry bark, selecting the flat bark of a 1-year-old paper mulberry branch with a diameter of 3 cm, peeling and cutting into sections, the length of which is consistent with that of the celtis sinensis bark after processing (the consistency of length is to mix the two raw materials well); (2) Dry in the shade: Place the cut Pteris tannins and Paper mulberry bark in a cool place for later use. Most of the moisture in the bast fiber will be eliminated after drying in the shade, which will not only retain the effective part of the bast fiber, but also avoid irregular breakage of the bast fiber, which will affect the smoothness of the fiber. (3) Soaking: Soak the cut Pteris tannins and Paper mulberry bark in water for 24 hours and then take them out for later use; (4) Pressure: The soaked Phellodendron chinense bark and Paper mulberry bark are folded and turned over continuously, and after each folding and turning, a heavy object is used to press firmly from the top, and this process is repeated 100 times to obtain soft Phellodendron chinense bark and Paper mulberry bark; (5) Steaming: Put the soft Pteris tannins and Paper mulberry bark into an iron pot, add 4% of the dry pulp weight of soda ash for steaming, and gradually increase the temperature until it reaches 100 degrees Celsius. Keep the temperature for 4 hours and then cool naturally. After cooling, wash with water and sort manually. (6) Bleaching: The steamed and sorted Pteris chinensis bark and Paper mulberry bark are bleached with hydrogen peroxide and then washed; (7) Explain: The beating machine is used to simulate the action of pounding rice in ancient times to beat the bark of Pteris chinensis and Paper mulberry respectively. The beating time is 20 minutes. The function of beating is to pull the fiber and make it spread around to form fiber fluff. The advantage of using a beating machine instead of manpower or other external forces is that the beating direction can be evenly controlled to avoid favoritism, and the beating force and quantity in each direction are relatively uniform. This controllable beating can greatly ensure the integrity of the fiber and avoid fiber breakage or fiber bunching caused by uneven beating. (8) Beating: The beaten Pteris tannin bark and Paper mulberry bark were mixed and placed in a pulping device. After 40 minutes of cutting and stirring in the pulping device, pulp with a beating degree of 32 degrees was obtained. The function of pulping is to cut and break the fiber fluff, and after obtaining the crushed mass, it is easy to form a more delicate fiber pulp. (9) Sand removal: Adjust the pulp concentration to 5‰ and remove impurities through a desander and a round screen; (10) Slurry preparation: Add paper medicine to the slurry and stir evenly, then add Coptis chinensis insect-proof processing liquid and anti-mildew processing liquid; (11) Fishing paper: The paper scooping equipment is used for scooping paper, the scooping method is curtain hanging, and the thickness of single layer of paper is 23g; (12) Pressing: Use a 50T jack to squeeze the water out of the paper; (13) Drying paper: The temperature of the baking wall for drying paper is below 60℃, and the second layer is dried; (14) Processing: The finished paper is sizing, grinding and calendering, specifically: sizing the finished paper to enhance the water resistance of the paper, then grinding to remove burrs and unevenness on the surface of the paper, and finally calendering to improve the gloss and smoothness of the paper; (15) Physical and chemical index testing, including wet strength, fracture resistance test, tear strength, and aging resistance whiteness test.

[0019] The appearance of the produced paper is raw and ripe, and its ink absorbency meets the requirements of Song Dynasty calligraphy and painting. The appearance of the paper has the characteristics of "skin like egg membrane, hard like jade".

[0020] like Figure 1 As shown, the paper scooping equipment includes a high platform 1 and a bamboo curtain platform 2. A baffle 3 is provided at the front upper end of the high platform 1. The baffle 3 is connected to a lifting rod 4 for driving the up and down movement. A downstream plate 5 is provided in the middle of the front end of the high platform 1. The bamboo curtain platform 2 is located in the front and lower part of the downstream plate 5. The slurry is placed on the high platform 1, and a plurality of bamboo curtains 6 are placed on the top of the bamboo curtain platform 2. The baffle 3 of the high platform 1 is opened to allow the slurry to be gradually spread on the bamboo curtain 6 under the action of gravity. The slurry layers on the bamboo curtain 6 are stacked layer by layer, and then the water is controlled and the paper is dried.

[0021] like Figure 2 As shown, there are three bamboo curtains 6, each bamboo curtain 6 is slightly tilted, and the heights of the three bamboo curtains 6 gradually decrease from the back to the front to facilitate the flow of slurry.

[0022] Step (2) is as follows: evenly spread the cut Phellodendron chinense bark and Paper mulberry bark on a bamboo drying rack that is well ventilated, avoids direct sunlight and has a moderate humidity; lay a layer of pure cotton coarse cloth under the drying rack to absorb any dripping moisture; gently turn the Phellodendron chinense bark and Paper mulberry bark every 2 hours to ensure that all parts of the bark are evenly exposed to the wind; at the same time, place bamboo baskets filled with natural camphor wood blocks around the shade drying area, using the smell of the camphor wood to repel insects and prevent moths, ensuring that the Phellodendron chinense bark and Paper mulberry bark are not attacked by insects and ants during the shade drying process, until their moisture content is reduced to 15%, reaching a suitable state for standby use.

[0023] Step (3) is as follows: prepare two large ceramic vats, fill the vats with spring water in advance, carefully place the cut cinnabar bark and paper mulberry bark into different ceramic vats, and ensure that the bark is completely immersed in the water; cover the mouth of the vat with a layer of breathable fine yarn to prevent foreign matter from falling in; then, add finely ground shell powder into the water, the particle size of the shell powder is less than 0.1 mm; at the same time, place a number of polished pebbles at the bottom of the vat to promote slight disturbance of the water flow; replace the water in the vat every 6 hours, and take it out after soaking for 24 hours. The main component of shell powder is calcium carbonate, which has a certain softening and cleaning effect. It helps to remove impurities, grease or other substances that are not conducive to the subsequent papermaking process on the surface of cinnabar bark and paper mulberry bark, making the bark purer and easier to process in the subsequent treatment, which may help to improve the quality and performance of paper.

[0024] Step (4) is specifically as follows: a wooden pressure platform is used, the surface of which is flat and smooth and has good air permeability, the soaked cinnabar bark and paper mulberry bark are laid flat on the platform respectively, and the leather is folded and turned over continuously with bamboo strips. After each folding and turning, a granite stone with fine textures on the surface is placed on the top of the leather. The weight of these stones is adjusted according to the state of the leather and the progress of the processing. The initial weight is 20 kg and gradually increases to 50 kg. During the pressure application process, the placement of the leather is changed every 5 folding and turning to ensure that all parts of the leather are evenly pressed. This operation is repeated 100 times until the cinnabar bark and paper mulberry bark are soft and tough. The fine texture of the granite stone can make the pressure more evenly distributed on the leather, avoiding the situation where the local pressure is too large or too small, so that the overall texture of the leather is more uniform during the folding and turning pressure process. In addition, the texture can increase the friction between the stone and the leather, preventing the stone from sliding during the pressure application process, and ensuring that the pressure acts stably on the leather.

[0025] In step (5), the temperature is gradually increased at a rate of 2 degrees Celsius per minute. During the heating process, the material in the pot is slowly stirred every 15 minutes using a stirring rod made of nanmu bamboo. The stirring speed is maintained at 10 revolutions per minute to ensure that the leather is heated evenly. When the temperature rises to 100 degrees Celsius, this temperature is maintained constant for 4 hours.

[0026] Step (6) is specifically as follows: neatly stack the steamed and sorted Pteris tannins and Paper mulberry barks in a stirring container, prepare hydrogen peroxide for bleaching, and treat the hydrogen peroxide with ultraviolet light for 30 minutes in advance to enhance its activity; then, slowly inject hydrogen peroxide into the container to ensure that the hydrogen peroxide completely immerses the leather; then, install a set of devices that can generate weak ultrasonic waves above the container, turn on the ultrasonic waves to allow the hydrogen peroxide to penetrate and act more evenly between the leathers; during the bleaching process, use a glass stirring rod to gently stir the leather every 30 minutes, and keep the stirring speed at 5 revolutions per minute; after bleaching for 2 hours, stop the ultrasonic wave and stirring, and drain the hydrogen peroxide; then, use soft water at a temperature of 30 degrees Celsius to rinse the leather several times, and constantly turn the leather over during the rinsing process to ensure that the residual hydrogen peroxide is completely removed, and rinse for 15 minutes each time, for a total of 3 rinses.

[0027] In step (7), the beating machine is stopped every 5 minutes and the leather is turned over manually to ensure that all parts of the leather are fully and evenly beated.

[0028] In step (8), the Pteris chinensis bark and the paper mulberry bark are mixed and placed in the barrel of the pulping device. After the pulping device is started, the blade rotates at a speed of 1500 revolutions per minute to cut and stir the leather. The inner wall of the barrel is provided with a number of tiny protrusions to enhance the friction and kneading effect on the leather.

[0029] The paper prepared by the present invention was compared with rice paper. The paper was cut into a size of 131CM in length and 66CM in width with the same thickness. Wet strength test, fracture resistance test and tear strength test were performed, as shown in Table 1 below:

[0030] The paper prepared by the present invention was compared with rice paper to conduct an aging resistance whiteness test, and the comparison results are shown in Table 2 below:

[0031] In summary, the paper prepared by the present invention has high wet strength and good aging resistance and whiteness.

[0032] The reasons why the paper of the present invention has high wet strength and good aging resistance and whiteness are as follows: First of all, the manufacturing process of the present invention encompasses a number of delicate steps and forms an integration, such as soaking, pressing, boiling, bleaching, beating and pulping. These steps act together on the raw materials to make their fibers more delicate, soft and resilient. In the boiling step, by gradually increasing the temperature and maintaining it for a certain time, the fibers are fully softened and impurities are removed, which helps to improve the strength and durability of the paper. In the bleaching step, hydrogen peroxide and ultrasonic technology are used to make the bleaching more uniform and thorough, reducing the discoloration and aging of the paper caused by incomplete bleaching. In the beating process, the implementation of the beating force, quantity, angle and area is balanced, which further improves the pulling and diffusion of the paper fibers, avoids the occurrence of clumping and bundling, and greatly ensures the integrity of the paper fibers.

[0033] Secondly, the present invention adds a coptis chinensis insect-proof processing liquid and a mildew-proof processing liquid in the pulping step. These additives can effectively prevent the paper from being damaged by microorganisms, such as bacteria and molds, during long-term storage. These microorganisms may decompose the fibers in the paper, causing the paper to age, discolor or even break. By adding these insect-proof and mildew-proof agents, the present invention significantly improves the anti-aging whiteness performance of the paper, allowing it to maintain its original color and strength for a longer period of time.

[0034] In addition, the present invention takes special measures to prevent insects and ants from invading during the shade drying step. Bamboo baskets filled with natural camphor wood blocks are placed around the shade drying area, and the smell of the camphor wood is used to repel insects and prevent moths. This measure not only ensures that the bark of the Chinese taro and the paper mulberry bark are not invading during the shade drying process, but also reduces the potential damage to the paper fibers caused by the activities of insects and ants, thereby helping to improve the aging resistance and whiteness of the paper.

[0035] Finally, the paper scooping, pressing, drying and processing steps of the present invention have also been carefully designed and optimized. For example, the use of curtain-type paper scooping equipment in the paper scooping process can ensure the uniformity and thickness consistency of the paper; the use of a jack to squeeze out water in the pressing process reduces the moisture content in the paper, which helps to improve the dryness and stability of the paper; the baking wall temperature is controlled in the paper drying process to avoid deformation and aging of the paper due to excessive temperature. These measures work together in the paper manufacturing process, making it have better aging resistance and whiteness performance.

[0036] In summary, the reasons for the good aging resistance and whiteness of the present invention also include the addition of chemical additives, the fine processing of raw materials, the optimization of the production process, and the careful design and control of the subsequent processing steps. These factors work together to make the paper prepared by the present invention have higher wet strength and better aging resistance and whiteness performance, and can meet the strict requirements of high-end artworks such as Song Dynasty calligraphy and painting on paper quality.

Claims

1. A production process for restoring the properties of Chengxintang paper, characterized in that The following steps are involved: (1) Material selection: Select the bark of Pteris chinensis and Chu bark as the raw materials for making paper. Prepare 2 pieces of Pteris chinensis bark, select the bark of Pteris chinensis branches with a growth period of more than 3 years, peel it and cut it into sections of 90 cm; prepare 1 piece of Paper mulberry bark, select the flat bark of a 1-year-old Paper mulberry branch with a diameter of 3 cm, peel it and cut it into sections, the length of which is the same as that of the Pteris chinensis bark after processing; (2) Dry in the shade: Place the cut Pteris tannins and Paper mulberry bark in a cool place for later use; (3) Soaking: Soak the cut Pteris tannins and Paper mulberry bark in water for 24 hours and then take them out for later use; (4) Pressure: The soaked Phellodendron chinense bark and Paper mulberry bark are folded and turned over continuously, and after each folding and turning, a heavy object is used to press firmly from the top, and this process is repeated 100 times to obtain soft Phellodendron chinense bark and Paper mulberry bark; (5) Steaming: Put the soft Pteris tannins and Paper mulberry bark into an iron pot, add 4% of the dry pulp weight of soda ash for steaming, and gradually increase the temperature until it reaches 100 degrees Celsius. Keep the temperature for 4 hours and then cool naturally. After cooling, wash with water and sort manually. (6) Bleaching: The steamed and sorted Pteris chinensis bark and Paper mulberry bark are bleached with hydrogen peroxide and then washed; (7) Explain: Use a pounding machine to simulate the ancient rice pounding action to pound the bark of Pteris chinensis and the bark of Paper mulberry for 20 minutes. (8) Beating: The beaten Pteris tannin bark and Paper mulberry bark were mixed and placed in a pulping device, and the pulping device was used for 40 minutes to cut and stir the pulp to obtain a pulp with a beating degree of 32 degrees; (9) Sand removal: Adjust the pulp concentration to 5‰ and remove impurities through a desander and a round screen; (10) Slurry preparation: Add paper medicine to the slurry and stir evenly, then add Coptis chinensis insect-proof processing liquid and anti-mildew processing liquid; (11) Fishing paper: The paper scooping equipment is used for scooping paper, the scooping method is curtain hanging, and the thickness of single layer of paper is 23g; (12) Pressing: Use a 50T jack to squeeze the water out of the paper; (13) Drying paper: The temperature of the baking wall for drying paper is below 60℃, and the second layer is dried; (14) Processing: Finished paper is sized, polished and calendered; (15) Physical and chemical index testing.

2. The process for restoring the properties of Chengxintang paper according to claim 1, characterized in that: The paper scooping equipment includes a high platform and a bamboo curtain platform. A baffle is provided at the upper front end of the high platform, and the baffle is connected to a lifting rod for driving the up and down movement. A downstream plate is provided in the middle of the front end of the high platform, and the bamboo curtain platform is located in the front and lower part of the downstream plate. The slurry is placed on the high platform, and multiple bamboo curtains are placed on the top of the bamboo curtain platform. The baffle of the high platform is opened to allow the slurry to be gradually spread on the bamboo curtain under the action of gravity.

3. The process for restoring the properties of Chengxintang paper according to claim 1, characterized in that: Step (2) is as follows: evenly spread the cut Phellodendron chinense bark and Paper mulberry bark on a bamboo drying rack that is well ventilated, avoids direct sunlight and has moderate humidity; lay a layer of pure cotton coarse cloth under the drying rack; gently turn the Phellodendron chinense bark and Paper mulberry bark every 2 hours to ensure that all parts of the bark are evenly exposed to the wind; at the same time, place bamboo baskets filled with natural camphor wood blocks around the shade drying area, using the smell of the camphor wood to repel insects and prevent moths, ensuring that the Phellodendron chinense bark and Paper mulberry bark are not attacked by insects and ants during the shade drying process, until their moisture content is reduced to 15%, reaching a suitable state for standby use.

4. The process for restoring the properties of Chengxintang paper according to claim 1, characterized in that: Step (3) is as follows: prepare two large ceramic vats, fill the vats with spring water in advance, carefully place the cut Pteris tannin bark and Paper mulberry bark into different ceramic vats respectively, and ensure that the bark is completely immersed in the water; cover the mouth of the vat with a layer of breathable fine yarn to prevent foreign matter from falling into it; then, add finely ground shell powder with a particle size of less than 0.1 mm into the water; at the same time, place a number of polished pebbles at the bottom of the vat to promote slight disturbance of the water flow; replace the water in the vat every 6 hours, and take it out after soaking for 24 hours.

5. The process for restoring the properties of Chengxintang paper according to claim 1, characterized in that: Step (4) is specifically as follows: a wooden pressure platform is used, the surface of the platform is flat and smooth and has good air permeability, the soaked cinnabar bark and paper mulberry bark are spread flat on the platform respectively, and the leather is folded and turned over continuously using bamboo strips. After each folding and turning, a granite stone with a fine texture engraved on the surface is placed on the top of the leather. The weight of these stones is adjusted according to the state of the leather and the processing progress. The initial weight is 20 kg and gradually increases to 50 kg. During the pressure process, the placement of the leather is changed every 5 folding and turning to ensure that all parts of the leather are evenly pressurized. This operation is repeated 100 times until the cinnabar bark and paper mulberry bark are soft and tough.

6. The process for restoring the properties of Chengxintang paper according to claim 1, characterized in that: In step (5), the temperature is gradually increased at a rate of 2 degrees Celsius per minute. During the heating process, the material in the pot is slowly stirred every 15 minutes using a stirring rod made of nanmu bamboo. The stirring speed is maintained at 10 revolutions per minute to ensure that the leather is heated evenly. When the temperature rises to 100 degrees Celsius, this temperature is maintained constant for 4 hours.

7. The process for restoring the properties of Chengxintang paper according to claim 1, characterized in that: Step (6) is specifically as follows: neatly stack the steamed and sorted Pteris tannins and Paper mulberry barks in a stirring container, prepare hydrogen peroxide for bleaching, and treat the hydrogen peroxide with ultraviolet light for 30 minutes in advance to enhance its activity; then, slowly inject hydrogen peroxide into the container to ensure that the hydrogen peroxide completely immerses the leather; then, install a set of devices that can generate weak ultrasonic waves above the container, turn on the ultrasonic waves to allow the hydrogen peroxide to penetrate and act more evenly between the leathers; during the bleaching process, use a glass stirring rod to gently stir the leather every 30 minutes, and keep the stirring speed at 5 revolutions per minute; after bleaching for 2 hours, stop the ultrasonic wave and stirring, and drain the hydrogen peroxide; then, use soft water at a temperature of 30 degrees Celsius to rinse the leather several times, and constantly turn the leather over during the rinsing process to ensure that the residual hydrogen peroxide is completely removed, and rinse for 15 minutes each time, for a total of 3 rinses.

8. The process for restoring the properties of Chengxintang paper according to claim 1, characterized in that: In step (7), the beating machine is stopped every 5 minutes and the leather is turned over manually to ensure that all parts of the leather are fully and evenly beated.

9. The process for restoring the properties of Chengxintang paper according to claim 1, characterized in that: In step (8), the Pteris tannin bark and the Paper mulberry bark are mixed and placed in the barrel of the pulping device. After the pulping device is started, the blade rotates at a speed of 1500 revolutions per minute to cut and stir the leather.

10. The process for restoring the properties of Chengxintang paper according to claim 9, characterized in that: The inner wall of the barrel is provided with a number of tiny protrusions to enhance the friction and kneading effect on the leather.

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