High-strength environment-friendly corrugated paper and preparation method thereof
By synergistically modifying wood pulp fibers with phytic acid, chitosan, and glycidyltrimethylammonium chloride, a multi-crosslinked interface structure was constructed, which solved the problem of decreased corrugated paper strength caused by increased proportion of recycled fibers. This enabled the preparation of high-strength environmentally friendly corrugated paper and improved the mechanical properties and stability of corrugated paper.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGSU YONGJIU PAPER CO LTD
- Filing Date
- 2026-03-02
- Publication Date
- 2026-04-10
AI Technical Summary
When the proportion of recycled fibers used in corrugated paper increases, the fiber length shortens and the number of surface active groups decreases, resulting in a decline in the ring crush strength, edge crush strength and folding endurance of corrugated paper. Traditional reinforcement methods have limited interfacial interaction and insufficient environmental performance.
Phytic acid, chitosan, and glycidyltrimethylammonium chloride were used to synergistically modify wood pulp fibers to construct a multi-crosslinked interface structure. This structure was then compounded with regenerated fibers, L-proline, cationic starch, nanocellulose, and various environmentally friendly additives to form stable multi-point binding sites, thereby improving the bonding ability between fibers.
It significantly improves the ring crush strength, edge crush strength and folding endurance of corrugated paper, and maintains good structural stability under wet and cyclic compression conditions, meeting the reinforcement requirements of high proportion of recycled fibers, and the system is environmentally friendly and biodegradable.
Smart Images
Figure CN121827150A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of green paper-based materials and fiber modification technology, specifically relating to a high-strength environmentally friendly corrugated paper and its preparation method. Background Technology
[0002] Corrugated paper, as an important paper-based packaging material, is widely used in logistics and transportation, electronic product packaging, and agricultural and sideline product distribution. With the advancement of environmental protection policies and the increasing requirements for resource recycling, the proportion of recycled fibers used in corrugated paper is constantly increasing. However, during repeated reuse, recycled fibers experience shortened fiber length, reduced surface-active groups, and decreased inter-fiber bonding capacity, resulting in a significant decrease in the ring crush strength, edge crush strength, and folding endurance of corrugated paper.
[0003] In existing technologies, cationic starch, polyacrylamide-based reinforcing agents, or wet-strength resins are commonly used to modify corrugated paper to improve its strength. These reinforcement methods largely rely on single hydrogen bonding or physical adsorption, resulting in relatively simple interfacial bonding and limited reinforcing effects. Furthermore, some wet-strength resins leave formaldehyde residues or are difficult to degrade, which is detrimental to green and environmentally friendly requirements.
[0004] Traditional reinforcement systems primarily rely on in-pulp additions without structurally and synergistically modifying the wood pulp fiber matrix. This makes it difficult to construct a stable multi-layered cross-linked network structure at the molecular level, leading to significant performance degradation under high humidity or cyclic pressure conditions. Therefore, developing a high-strength, environmentally friendly corrugated paper material based on synergistic modification of the wood pulp fiber matrix and constructing a multi-interface reinforcement structure system to improve the synergistic enhancement of dry and wet strength has significant engineering application value and practical significance. Summary of the Invention
[0005] To overcome the problems in the aforementioned background technologies, such as decreased corrugated paper strength due to increased recycled fiber ratio and insufficient environmental performance of traditional reinforcement methods with limited interfacial interaction, the present invention aims to provide a high-strength, environmentally friendly corrugated paper and its preparation method. This invention employs a technical solution of synergistic modification of wood pulp fibers with phytic acid, chitosan, and glycidyltrimethylammonium chloride. The resulting synergistically modified wood pulp fibers are then compounded with recycled fibers, L-proline, cationic starch, nanocellulose, and various environmentally friendly additives to construct a corrugated paper material with a multi-layered cross-linked interfacial structure. This invention significantly enhances the interfiber bonding ability through synergistic modification of the wood pulp fiber matrix, improving the mechanical properties and performance stability of the corrugated paper while maintaining the material's environmental friendliness.
[0006] The objective of this invention can be achieved through the following technical solutions:
[0007] A high-strength environmentally friendly corrugated paper, comprising the following raw materials in parts by weight: 70-90 parts of synergistically modified wood pulp fiber; 10-40 parts of regenerated fiber; 0.2-2.0 parts of L-proline; 0.5-3.0 parts of cationic starch; 0.2-2.0 parts of nanocellulose; 0.05-0.5 parts of sodium bicarbonate; 0.05-0.8 parts of polyethylene glycol; and 0.02-0.3 parts of sodium dodecyl sulfate. The synergistically modified wood pulp fiber is obtained by synergistic modification treatment of phytic acid, chitosan, and glycidyltrimethylammonium chloride under weakly alkaline conditions through ion complexation reaction and epoxy ring-opening grafting reaction.
[0008] Optionally, the synergistically modified wood pulp fiber comprises the following raw materials in parts by weight: 80-100 parts wood pulp fiber; 0.5-5.0 parts phytic acid; 0.5-4.0 parts chitosan; and 0.5-6.0 parts glycidyltrimethylammonium chloride.
[0009] Optionally, the method for preparing synergistically modified wood pulp fibers includes the following steps:
[0010] (1) Disperse the wood pulp fibers in water to obtain a fiber dispersion pulp;
[0011] (2) Phytic acid and chitosan are added to the fiber dispersion slurry to carry out a complexation reaction to obtain a complexed modified slurry;
[0012] (3) Add glycidyltrimethylammonium chloride to the complexed modified pulp to carry out a grafting reaction to obtain synergistically modified wood pulp fibers.
[0013] Optionally, the reaction conditions in step (1) are: slurry mass concentration of 1-5%, stirring speed of 300-800 r / min, and dispersion time of 10-30 min.
[0014] Optionally, the reaction conditions in step (2) are a reaction temperature of 25–50 °C, a reaction time of 20–60 min, and a system pH of 4.0–6.5.
[0015] Optionally, the reaction conditions in step (3) are a reaction temperature of 40-70°C, a reaction time of 30-120 min, and a system pH of 7.5-9.5.
[0016] Optionally, a method for preparing high-strength environmentally friendly corrugated paper includes the following steps:
[0017] S1, wood pulp fibers are dispersed in water, and phytic acid, chitosan and glycidyltrimethylammonium chloride are added in sequence to carry out complexation and grafting reactions to obtain synergistically modified wood pulp fibers;
[0018] S2, the co-modified wood pulp fiber and the regenerated fiber are mixed and pulped, and then L-proline, cationic starch, nanocellulose, sodium bicarbonate, polyethylene glycol and sodium dodecyl sulfate are added and mixed and stirred to obtain a uniform composite pulp;
[0019] S3 involves processing the composite pulp through papermaking, pressing, and drying to obtain high-strength, environmentally friendly corrugated paper.
[0020] Optionally, the reaction conditions for step S1 are: slurry mass concentration of 1-5%, reaction temperature of 25-70℃, reaction time of 30-120 min, and system pH of 4.0-9.5.
[0021] Optionally, the reaction conditions in step S2 are a stirring speed of 300–800 r / min and a mixing time of 10–40 min.
[0022] Optionally, the reaction conditions for step S3 are: pressing pressure of 0.2–1.0 MPa, drying temperature of 80–130 °C, and drying time of 5–20 min.
[0023] The beneficial effects of this invention are:
[0024] This invention synergistically modifies wood pulp fibers using phytic acid, chitosan, and glycidyltrimethylammonium chloride. It constructs a multi-crosslinked network on the fiber surface, combining ionic complex structures with epoxy ring-opening graft structures. This creates stable multi-point binding sites on the fiber surface, improving interfacial bonding at the fiber bulk level. This approach departs from the traditional method of relying on single physical adsorption within the pulp for reinforcement, achieving a shift from external reinforcement to structural reinforcement. Specifically, the polyphosphate groups of phytic acid form a stable complex structure with the amino groups of chitosan, while glycidyltrimethylammonium chloride undergoes a ring-opening grafting reaction to introduce permanent cationic groups, increasing the surface charge density and reactivity of the fiber and enhancing the bonding strength with regenerated fibers and cationic starch. Simultaneously, L-proline participates in constructing an auxiliary hydrogen bond regulating network, further optimizing the microstructure of inter-fiber bonding. This significantly improves the ring crush strength, edge crush strength, and folding endurance of corrugated paper, maintaining good structural stability under wet and cyclic compression conditions. The system of this invention does not contain formaldehyde-based wet-strength resins, and the raw materials are environmentally friendly and biodegradable, making it suitable for reinforcing corrugated paper with a high proportion of regenerated fibers. Attached Figure Description
[0025] The invention will now be further described with reference to the accompanying drawings.
[0026] Figure 1 A comparison of the infrared spectra of wood pulp fibers and synergistically modified wood pulp fibers;
[0027] Figure 2 This is a comparison chart of the performance test results of ring crush strength and edge crush strength for samples with different formulation ratios. Detailed Implementation
[0028] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.
[0029] Example 1: The purpose of this example is to verify that, under the condition that all components and process parameters are taken at their lower limits, the present invention can still achieve the structural strengthening effect on the regenerated fiber system.
[0030] S1, Preparation of Synergistically Modified Wood Pulp Fibers
[0031] Take 80 parts of wood pulp fiber, add it to water, control the pulp mass concentration to 1%, and disperse it at 300 r / min for 10 min; add 0.5 parts of phytic acid, control the temperature to 25℃, the system pH to 4.0, and react for 20 min; add 0.5 parts of chitosan, and continue to react for 20 min; add 0.5 parts of glycidyltrimethylammonium chloride, adjust the system pH to 7.5, and react at 40℃ for 30 min to obtain synergistically modified wood pulp fiber;
[0032] S2, Preparation of composite slurry
[0033] Take 70 parts of synergistically modified wood pulp fiber and 10 parts of regenerated fiber, mix and pulp; add 0.2 parts of L-proline, 0.5 parts of cationic starch, 0.2 parts of nanocellulose, 0.05 parts of sodium bicarbonate, 0.05 parts of polyethylene glycol, and 0.02 parts of sodium dodecyl sulfate; mix at 300 r / min for 10 min to obtain composite pulp.
[0034] S3, Copying Modeling
[0035] The composite pulp was subjected to papermaking and forming, with a pressing pressure of 0.2 MPa, a drying temperature of 80℃, and a drying time of 5 min to obtain high-strength environmentally friendly corrugated paper.
[0036] Example 2: The purpose of this example is to verify the comprehensive strengthening effect of the synergistic modification system of the present invention under the condition that each component and process parameter are within the median range.
[0037] S1, Preparation of Synergistically Modified Wood Pulp Fibers
[0038] Take 90 parts of wood pulp fiber and control the pulp mass concentration to 3%; stir at 500 r / min and disperse for 20 min; add 2.5 parts of phytic acid and react at 35℃ and pH 5.5 for 40 min; add 2.0 parts of chitosan and continue to react for 40 min; add 3.0 parts of glycidyltrimethylammonium chloride, adjust the pH to 8.5, and react at 55℃ for 75 min to obtain synergistically modified wood pulp fiber; Figure 1Infrared spectral comparisons show that, before modification, wood pulp fibers exhibit a distinct –OH stretching vibration peak at 3330–3400 cm⁻¹, a –CH₂ stretching vibration peak at 2920 cm⁻¹, and a characteristic peak of cellulose C–O stretching vibration near 1050 cm⁻¹. After modification, a new –NH bending vibration peak appears at 1540–1560 cm⁻¹, and P=O and P–O related absorption peaks appear at 1240–1260 cm⁻¹ and 950–980 cm⁻¹, indicating successful introduction of phytic acid and chitosan. Simultaneously, the peak intensity near 1050 cm⁻¹ increases and shifts slightly, indicating a grafting reaction and alteration of the fiber surface chemical environment, demonstrating successful synergistic modification.
[0039] S2, Preparation of composite slurry
[0040] Take 80 parts of synergistically modified wood pulp fiber and 25 parts of regenerated fiber and mix them; add 1.0 part of L-proline, 1.5 parts of cationic starch, 1.0 part of nanocellulose, 0.25 parts of sodium bicarbonate, 0.4 parts of polyethylene glycol, and 0.15 parts of sodium dodecyl sulfate; stir at 500 r / min for 25 min.
[0041] S3, Copying Modeling
[0042] High-strength, environmentally friendly corrugated paper is obtained by pressing at a pressure of 0.6 MPa, drying at a temperature of 105℃, and drying for 12 minutes.
[0043] Example 3: The purpose of this example is to verify that the present invention still maintains system stability and structural enhancement effect under the condition that each component and process parameter is taken at the upper limit.
[0044] S1, Preparation of Synergistically Modified Wood Pulp Fibers
[0045] Take 100 parts of wood pulp fiber, with a pulp concentration of 5%; stir at 800 r / min and disperse for 30 min; add 5.0 parts of phytic acid and react at 50℃ and pH 6.5 for 60 min; add 4.0 parts of chitosan and continue reacting for 60 min; add 6.0 parts of glycidyltrimethylammonium chloride, adjust the pH to 9.5, and react at 70℃ for 120 min to obtain synergistically modified wood pulp fiber;
[0046] S2, Preparation of composite slurry
[0047] Take 90 parts of synergistically modified wood pulp fiber and 40 parts of regenerated fiber and mix them; add 2.0 parts of L-proline, 3.0 parts of cationic starch, 2.0 parts of nanocellulose, 0.5 parts of sodium bicarbonate, 0.8 parts of polyethylene glycol and 0.3 parts of sodium dodecyl sulfate; mix at 800 r / min for 40 min.
[0048] S3, Copying Modeling
[0049] High-strength, environmentally friendly corrugated paper is obtained by pressing at 1.0 MPa, drying at 130℃, and drying for 20 minutes.
[0050] Comparative Example 1: The purpose of this comparative example is to verify the effect of using only phytic acid to modify wood pulp fibers on the overall strengthening effect of corrugated paper.
[0051] S1, Preparation of single modified wood pulp fibers
[0052] Take 90 parts of wood pulp fiber and control the pulp mass concentration to 3%; stir at 500 r / min and disperse for 20 min; add 2.5 parts of phytic acid and react at 35℃ and pH 5.5 for 40 min; without adding chitosan and glycidyltrimethylammonium chloride, phytic acid-modified wood pulp fiber is obtained.
[0053] S2, Preparation of composite slurry
[0054] Take 80 parts of phytic acid-modified wood pulp fiber and 25 parts of regenerated fiber and mix them; add 1.0 part of L-proline, 1.5 parts of cationic starch, 1.0 part of nanocellulose, 0.25 parts of sodium bicarbonate, 0.4 parts of polyethylene glycol, and 0.15 parts of sodium dodecyl sulfate; stir at 500 r / min for 25 min.
[0055] S3, Copying Modeling
[0056] The pressing pressure was 0.6 MPa, the drying temperature was 105℃, and the drying time was 12 min to obtain corrugated paper.
[0057] Comparative Example 2: The purpose of this comparative example is to verify the effect of using only chitosan to modify wood pulp fibers on the overall strengthening effect of corrugated paper.
[0058] S1, Preparation of single modified wood pulp fibers
[0059] Take 90 parts of wood pulp fiber and control the pulp mass concentration to 3%; stir at 500 r / min and disperse for 20 min; add 2.0 parts of chitosan and react at 35℃ and pH 5.5 for 40 min; without adding phytic acid and glycidyltrimethylammonium chloride, chitosan-modified wood pulp fiber is obtained.
[0060] S2, Preparation of composite slurry
[0061] Take 80 parts of chitosan-modified wood pulp fiber and 25 parts of regenerated fiber and mix them; add 1.0 part of L-proline, 1.5 parts of cationic starch, 1.0 part of nanocellulose, 0.25 parts of sodium bicarbonate, 0.4 parts of polyethylene glycol, and 0.15 parts of sodium dodecyl sulfate; stir at 500 r / min for 25 min;
[0062] S3, Copying Modeling
[0063] The pressing pressure was 0.6 MPa, the drying temperature was 105℃, and the drying time was 12 min to obtain corrugated paper.
[0064] Comparative Example 3: The purpose of this comparative example is to verify the effect of not adding the organic small molecule L-proline on the overall strengthening effect of corrugated paper.
[0065] S1, Preparation of Synergistically Modified Wood Pulp Fibers
[0066] Take 90 parts of wood pulp fiber and control the pulp mass concentration to 3%; stir at 500 r / min and disperse for 20 min; add 2.5 parts of phytic acid and react at 35℃ and pH 5.5 for 40 min; add 2.0 parts of chitosan and continue to react for 40 min; add 3.0 parts of glycidyltrimethylammonium chloride, adjust the pH to 8.5, and react at 55℃ for 75 min to obtain synergistically modified wood pulp fiber;
[0067] S2, Preparation of composite slurry
[0068] Take 80 parts of synergistically modified wood pulp fiber and 25 parts of regenerated fiber and mix them; do not add L-proline; add 1.5 parts of cationic starch, 1.0 part of nanocellulose, 0.25 parts of sodium bicarbonate, 0.4 parts of polyethylene glycol, and 0.15 parts of sodium dodecyl sulfate; stir at 500 r / min for 25 min;
[0069] S3, Copying Modeling
[0070] The pressing pressure was 0.6 MPa, the drying temperature was 105℃, and the drying time was 12 min to obtain corrugated paper.
[0071] 1. Ring crush strength test method
[0072] The prepared corrugated paper was conditioned for 24 hours at 23±1℃ and 50±2% relative humidity, then cut into strips 12.7 mm wide and 152 mm long. The strips were rolled into cylinders and placed in a ring crush test fixture. A universal testing machine was used for compression testing at a loading speed of 12.5 mm / min. The maximum load value at which the sample failed was recorded and converted into ring crush strength (kN / m). Each group of samples was tested at least 5 times, and the average value was taken as the final result.
[0073] 2. Edge crush strength test method
[0074] Corrugated paper was cut into 100mm × 25mm specimens. After conditioning under constant temperature and humidity for 24 hours, the specimens were placed in an edge crush test apparatus with the corrugation direction perpendicular to the loading direction. Compression tests were performed using an electronic pressure testing machine at a loading speed of 12.5mm / min. The maximum load value at which structural failure occurred was recorded, and the edge crush strength (kN / m) was calculated. At least five parallel samples were tested for each group of specimens, and the average value was taken.
[0075] 3. Test method for flexural endurance
[0076] Corrugated paper was cut into 15mm × 100mm sample strips. After conditioning in a standard environment for 24 hours, the folding endurance was tested using an MIT folding endurance tester. The tension was set to 9.8N and the folding angle to 135°. The number of folds before the sample broke was recorded. Each test was performed at least 5 times, and the average value was taken as the folding endurance performance index.
[0077] 4. Wet strength retention rate test method
[0078] After conditioning the sample under standard conditions, determine its dry ring crush strength. Then, immerse the sample in deionized water for 5 minutes, remove it, and absorb the surface moisture with filter paper. Complete the wet ring crush strength test within 30 seconds. The wet strength retention rate is calculated as follows: wet ring crush strength / dry ring crush strength × 100%. Each test group should have no less than 5 parallel samples, and the average value should be taken.
[0079] Table 1. Performance Test Results of High-Strength Environmentally Friendly Corrugated Paper
[0080] Sample number Ring crush strength (kN / m) Edge compressive strength (kN / m) Number of folding cycles Wet strength retention rate (%) Example 1 8.1 6.4 85 68 Example 2 9.8 7.9 132 82 Example 3 9.2 7.4 118 76 Comparative Example 1 7.2 5.6 62 55 Comparative Example 2 7.4 5.9 70 58 Comparative Example 3 8.0 6.3 92 65
[0081] As shown in Table 1, Examples 1-3 are significantly better than Comparative Examples 1-3 in terms of ring crush strength, edge crush strength, folding endurance, and wet strength retention. This indicates that by synergistically modifying wood pulp fibers with phytic acid, chitosan, and glycidyltrimethylammonium chloride, and constructing an auxiliary hydrogen bond network with L-proline, the overall mechanical properties and structural stability of corrugated paper can be effectively improved.
[0082] Based on the ring crush strength and edge crush strength data, Example 2 achieved 9.8 kN / m and 7.9 kN / m, respectively, significantly higher than the 7.2–7.4 kN / m and 5.6–5.9 kN / m of Comparative Example 1 and Comparative Example 2, respectively. This indicates that single phytic acid or single chitosan modification is insufficient to form a stable multi-crosslinked structure, while the synergistic modification system can enhance the interfiber bonding interface and improve compressive strength. Although Example 3 was at the upper limit, its performance was slightly lower than that of Example 2, indicating that a more uniform and stable network structure is more favorable under appropriate ratios and reaction conditions.
[0083] In terms of flexural endurance, Example 2 achieved 132 flexural cycles, significantly higher than the 62 and 70 cycles of Comparative Examples 1 and 2, respectively. This indicates that synergistic modification not only enhances the static bonding strength between fibers but also improves the structural toughness of the fiber network during repeated bending. Comparative Example 3, without the addition of L-proline, achieved 92 flexural cycles, lower than Example 2, demonstrating that the auxiliary hydrogen bond network constructed with the participation of small organic molecules has a positive effect on improving flexibility.
[0084] Analysis of the wet strength retention rate data shows that Example 2 reached 82%, which is significantly higher than 55% and 58% of Comparative Examples 1 and 2, respectively, and also higher than 65% of Comparative Example 3. This indicates that the multi-crosslinked structure formed by the synergistic modification system has better stability in the water environment, and the introduction of L-proline further improves the wet structure retention ability.
[0085] In summary, by synergistically modifying wood pulp fibers with phytic acid, chitosan, and glycidyltrimethylammonium chloride, and introducing L-proline to construct an auxiliary binding network, the best strengthening effect can be obtained under appropriate composition and process conditions, significantly improving the compressive strength, folding endurance, and wet stability of corrugated paper, thus verifying the effectiveness and technical advantages of the synergistic modification system of this invention.
Claims
1. A high-strength, environmentally friendly corrugated paper, characterized in that, The environmentally friendly corrugated paper comprises the following raw materials in parts by weight: 70-90 parts of synergistically modified wood pulp fiber; 10-40 parts of regenerated fiber; 0.2-2.0 parts of L-proline; 0.5-3.0 parts of cationic starch; 0.2-2.0 parts of nanocellulose; 0.05-0.5 parts of sodium bicarbonate; 0.05-0.8 parts of polyethylene glycol; and 0.02-0.3 parts of sodium dodecyl sulfate. The synergistically modified wood pulp fiber is obtained by synergistic modification treatment of phytic acid, chitosan, and glycidyltrimethylammonium chloride under weakly alkaline conditions through ion complexation reaction and epoxy ring-opening grafting reaction.
2. The high-strength environmentally friendly corrugated paper according to claim 1, characterized in that, The synergistically modified wood pulp fiber comprises the following raw materials in parts by weight: 80-100 parts wood pulp fiber; 0.5-5.0 parts phytic acid; 0.5-4.0 parts chitosan; and 0.5-6.0 parts glycidyltrimethylammonium chloride.
3. A high-strength environmentally friendly corrugated paper according to claim 1 or 2, characterized in that, The method for preparing the synergistically modified wood pulp fiber includes the following steps: (1) Disperse the wood pulp fibers in water to obtain a fiber dispersion pulp; (2) Phytic acid and chitosan are added to the fiber dispersion slurry to carry out a complexation reaction to obtain a complexed modified slurry; (3) Add glycidyltrimethylammonium chloride to the complexed modified pulp to carry out a grafting reaction to obtain synergistically modified wood pulp fibers.
4. The high-strength environmentally friendly corrugated paper according to claim 3, characterized in that, The reaction conditions for step (1) are: slurry mass concentration of 1-5%, stirring speed of 300-800 r / min, and dispersion time of 10-30 min.
5. The high-strength environmentally friendly corrugated paper according to claim 3, characterized in that, The reaction conditions for step (2) are a reaction temperature of 25-50℃, a reaction time of 20-60 min, and a system pH of 4.0-6.
5.
6. The high-strength environmentally friendly corrugated paper according to claim 3, characterized in that, The reaction conditions for step (3) are a reaction temperature of 40-70℃, a reaction time of 30-120 min, and a system pH of 7.5-9.
5.
7. A method for preparing high-strength environmentally friendly corrugated paper, characterized in that, The preparation method includes the following steps: S1, wood pulp fibers are dispersed in water, and phytic acid, chitosan and glycidyltrimethylammonium chloride are added in sequence to carry out complexation and grafting reactions to obtain synergistically modified wood pulp fibers; S2, the co-modified wood pulp fiber and the regenerated fiber are mixed and pulped, and then L-proline, cationic starch, nanocellulose, sodium bicarbonate, polyethylene glycol and sodium dodecyl sulfate are added and mixed and stirred to obtain a uniform composite pulp; S3 involves processing the composite pulp through papermaking, pressing, and drying to obtain high-strength, environmentally friendly corrugated paper.
8. The method for preparing high-strength environmentally friendly corrugated paper according to claim 7, characterized in that, The reaction conditions for step S1 are as follows: slurry mass concentration of 1-5%, reaction temperature of 25-70℃, reaction time of 30-120 min, and system pH of 4.0-9.
5.
9. The method for preparing high-strength environmentally friendly corrugated paper according to claim 7, characterized in that, The reaction conditions for step S2 are a stirring speed of 300-800 r / min and a mixing time of 10-40 min.
10. The method for preparing high-strength environmentally friendly corrugated paper according to claim 7, characterized in that, The reaction conditions for step S3 are: pressing pressure of 0.2-1.0 MPa, drying temperature of 80-130℃, and drying time of 5-20 min.