Preparation method of corrugated paper

Abstract

The invention belongs to the technical field of preparation of corrugated paper, and particularly relates to a preparation method of corrugated paper. The preparation method of the corrugated paper comprises the following steps: (1) preparing mixed slurry; (2) preparing raw paper and a corrugated paper core; and (3) preparing the corrugated paper. According to the preparation method of the corrugated paper, larch sulfate wood pulp, bleached acacia pulp and bleached flax pulp are used as basic raw materials and are subjected to modification treatment through polyamidoamine, styrene-butadiene emulsion and polymethyl ethylene carbonate, meanwhile, a self-made binder is selected for adhesion, all the steps have a synergistic effect, and therefore the corrugated paper is prepared. And the prepared corrugated paper is ensured to have excellent bursting strength, puncture strength and edge pressure strength.

Description

Technical Field

[0001] The invention belongs to the technical field of corrugated paper preparation, and specifically relates to a method for preparing corrugated paper. Background Art

[0002] Corrugated paper is a composite material composed of curled or wavy fiberboard (corrugated) and flat cardboard on both sides. It has a hollow structure. With the development of economy and the improvement of people's living standards, the application of corrugated paper in the packaging field is becoming more and more extensive. Corrugated paper has many advantages such as light weight, low price, high strength and good cushioning performance.

[0003] The preparation process of traditional corrugated paper is relatively simple, usually using virgin wood pulp as the main raw material and through a certain processing technology. However, the strength of this type of corrugated paper is limited, especially when facing heavy objects or being impacted by large external forces, it is prone to deformation, cracking and other problems, affecting its packaging performance.

[0004] In addition, the strength of existing corrugated paper will be greatly affected when it is exposed to a humid environment. Due to the water absorption of the paper itself, when the humidity is high or it comes into contact with moisture, the corrugated paper is prone to softening and deformation, resulting in a significant decrease in its packaging performance. Therefore, how to improve the strength of corrugated paper has become an urgent problem to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing corrugated paper. The corrugated paper prepared by the method has excellent bursting strength, puncture strength and edge compression strength.

[0006] The method for preparing corrugated paper of the present invention comprises the following steps: (1) crushing and beating larch kraft pulp, bleached acacia pulp and bleached flax pulp respectively to obtain larch kraft pulp slurry, bleached acacia pulp slurry and bleached flax pulp slurry, and then mixing the larch kraft pulp slurry, bleached acacia pulp slurry and bleached flax pulp slurry to prepare a mixed slurry; (2) adding polyamide amine and citric acid to the mixed slurry prepared in step (1) and stirring for 25-30 minutes, heating to 85-88° C. for condensation for 12-14 minutes, then adding styrene-butadiene emulsion and Tween-80 and stirring for 35-38 minutes, and finally adding polymethyl ethylene carbonate and stirring for 15-20 minutes to prepare base paper pulp, using a papermaking machine to prepare base paper from the base paper pulp, and preparing a corrugated paper core by corrugating the base paper; (3) The surface of the corrugated paper core is evenly coated with an adhesive, and then two pieces of base paper are respectively bonded to the upper and lower sides of the corrugated paper core, and corrugated paper is prepared by drying and baking.

[0007] in: The bleached acacia pulp in step (1) was purchased from Asia Pacific Sun Paper (Shandong) Co., Ltd., the larch kraft pulp was purchased from Nine Dragons Xingan Pulp and Paper (Inner Mongolia) Co., Ltd., and the bleached flax pulp was purchased from Mudanjiang Hengfeng Paper Co., Ltd.

[0008] In step (1), the mass ratio of larch kraft pulp, bleached acacia pulp and bleached flax pulp is 5.7:2.5:1.8.

[0009] In step (1), the beating degree of larch kraft pulp slurry is 30°SR, and the mass concentration of larch kraft pulp slurry is 4.4%; the beating degree of bleached acacia pulp slurry is 35°SR, and the mass concentration of bleached acacia pulp slurry is 5.2%; the beating degree of bleached flax pulp slurry is 25°SR, and the mass concentration of bleached flax pulp slurry is 3.5%.

[0010] In step (2), the mass of the polyamide amine accounts for 1.2-1.3% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of the styrene-butadiene emulsion accounts for 2.5-2.7% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of the polymethyl ethylene carbonate accounts for 0.8-1.0% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of Tween-80 accounts for 0.2% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; and citric acid is added to adjust the pH value of the system to 5.5.

[0011] The temperature of corrugating in step (2) is 175-178°C.

[0012] In step (3), the drying temperature is 40-45°C, the drying time is 1-1.2h, the drying temperature is 105-108°C, and the drying time is 38-40min.

[0013] The preparation method of the binder in step (3) comprises the following steps: mixing modified corn starch, phosphate starch and water, stirring and dissolving at 78-80°C for 35-38 minutes, then adding epichlorohydrin and continuing stirring for 23-25 ​​minutes, and cooling to 30-33°C after vacuuming to prepare the binder.

[0014] in: The mass ratio of modified corn starch to phosphate starch is 6-7:1.

[0015] The mass of water is 2.8 times the mass of modified corn starch and phosphate starch combined.

[0016] The mass of epichlorohydrin accounts for 2.4-2.6% of the mass of modified corn starch.

[0017] The preparation method of the modified corn starch consists of the following steps: ① Mix corn starch and hydrochloric acid and stir to dissolve at 55℃ for 2.2h, then add sodium hydroxide to adjust the system to a neutral environment, raise the temperature to 70℃ and continue stirring for 40min to gelatinize; ② Cool the reaction system to 55°C, add dodecyl dimethyl betaine, styrene-acrylic acid copolymer and ammonium persulfate, then add hydrochloric acid to adjust the pH value of the reaction system to 4.5, and finally raise the temperature to 75°C to continue the reaction for 1.6 hours. After the reaction is completed, add resorcinol to terminate the reaction; ③ Sodium bicarbonate was added to adjust the pH value of the reaction system to 6.0, and modified corn starch was prepared through post-treatment.

[0018] in: In step ①, the mass volume ratio of corn starch to hydrochloric acid is 1:2.4, in g / mL.

[0019] In step ②, the mass of dodecyl dimethyl betaine accounts for 2.5% of the mass of corn starch, the mass of styrene-acrylic acid copolymer accounts for 22% of the mass of corn starch, the mass of ammonium persulfate accounts for 0.4% of the mass of corn starch, and the mass of resorcinol accounts for 3.5% of the mass of corn starch.

[0020] The post-treatment in step ③ is ethanol precipitation, distilled water washing, centrifugation, and then drying at 55° C. for 8 hours.

[0021] Compared with the prior art, the present invention has the following beneficial effects: (1) The method for preparing corrugated paper of the present invention uses larch kraft pulp, bleached acacia pulp and bleached flax pulp as the main papermaking raw materials, and the three are used in combination to fundamentally ensure the strength of the prepared corrugated paper. Among them, larch kraft pulp itself has good moisture resistance, strength and good tear resistance, and plays a role in skeleton support, but its flexibility is poor; while bleached acacia pulp can fill the fiber gap, improve the uniformity, and enhance the interlayer bonding strength; in addition, bleached flax pulp is added, which can enhance the flexibility of corrugated paper, reduce the delamination and brittle cracking of corrugated paper, and improve the durability of corrugated paper.

[0022] (2) In the method for preparing corrugated paper of the present invention, polyamide amine forms a cross-linked network by chemically reacting with the hydroxyl functional groups on the fiber surface, thereby enhancing the dry strength and wet strength of the paper; citric acid acts as a catalyst to accelerate the condensation reaction; the added styrene-butadiene emulsion forms a film on the fiber surface, thereby enhancing the bonding force between the fibers and improving the tensile strength and folding endurance of the paper; and the carbonate groups of polymethylethylene carbonate weakly interact with the hydroxyl groups of cellulose, and its addition can improve the waterproof performance of the corrugated paper. The synergistic effect of the three ensures the strength of the prepared corrugated paper.

[0023] (3) The preparation method of corrugated paper described in the present invention uses modified corn starch and phosphate starch in the adhesive, and uses epichlorohydrin as a cross-linking agent. The modified corn starch has good bonding performance and water resistance, while the phosphate starch has better film-forming properties. Epichlorohydrin undergoes a cross-linking reaction with starch molecules to form epoxy starch with a three-dimensional network structure, thereby improving the strength and water resistance of the adhesive. Among them, the modified corn starch is firstly gelatinized by acid modification, and then ammonium persulfate is used as an initiator to initiate a free radical polymerization reaction between the styrene-acrylic acid copolymer and the starch molecules to form a modified corn starch with a grafted structure. Dodecyl dimethyl betaine can accelerate the penetration of starch adhesive into paper products and improve the bonding speed. As a result, the prepared adhesive has good bonding performance and water resistance.

[0024] (4) The method for preparing corrugated paper of the present invention uses larch kraft pulp, bleached acacia pulp and bleached flax pulp as basic raw materials, which are modified by polyamide amine, styrene-butadiene emulsion and polymethyl ethylene carbonate, and a homemade adhesive is used for adhesion. The synergistic effect between the various steps ensures that the prepared corrugated paper has excellent bursting strength, puncture strength and edge compression strength. DETAILED DESCRIPTION

[0025] The present invention is further described below with reference to the embodiments.

[0026] Example 1 The method for preparing the corrugated paper described in this embodiment 1 comprises the following steps: (1) crushing and beating larch kraft pulp, bleached acacia pulp and bleached flax pulp respectively to obtain larch kraft pulp slurry, bleached acacia pulp slurry and bleached flax pulp slurry, and then mixing the larch kraft pulp slurry, bleached acacia pulp slurry and bleached flax pulp slurry to prepare a mixed slurry; (2) adding polyamide amine and citric acid to the mixed slurry prepared in step (1) and stirring for 27 minutes, heating to 86° C. for condensation for 13 minutes, then adding styrene-butadiene emulsion and Tween-80 and stirring for 36 minutes, and finally adding polymethyl ethylene carbonate and stirring for 17 minutes to prepare base paper pulp, using a papermaking machine to prepare base paper from the base paper pulp, and preparing a corrugated paper core by corrugating the base paper; (3) The surface of the corrugated paper core is evenly coated with an adhesive, and then two pieces of base paper are respectively bonded to the upper and lower sides of the corrugated paper core, and corrugated paper is prepared by drying and baking.

[0027] in: The bleached acacia pulp in step (1) was purchased from Asia Pacific Sun Paper (Shandong) Co., Ltd., the larch kraft pulp was purchased from Nine Dragons Xingan Pulp and Paper (Inner Mongolia) Co., Ltd., and the bleached flax pulp was purchased from Mudanjiang Hengfeng Paper Co., Ltd.

[0028] In step (1), the mass ratio of larch kraft pulp, bleached acacia pulp and bleached flax pulp is 5.7:2.5:1.8.

[0029] In step (1), the beating degree of larch kraft pulp slurry is 30°SR, and the mass concentration of larch kraft pulp slurry is 4.4%; the beating degree of bleached acacia pulp slurry is 35°SR, and the mass concentration of bleached acacia pulp slurry is 5.2%; the beating degree of bleached flax pulp slurry is 25°SR, and the mass concentration of bleached flax pulp slurry is 3.5%.

[0030] In step (2), the mass of the polyamide amine accounts for 1.25% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of the styrene-butadiene emulsion accounts for 2.6% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of the polymethyl ethylene carbonate accounts for 0.9% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of Tween-80 accounts for 0.2% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; and citric acid is added to adjust the pH value of the system to 5.5.

[0031] The temperature of corrugating in step (2) is 176°C.

[0032] In step (3), the drying temperature is 43°C, the drying time is 1.1 h, the drying temperature is 106°C, and the drying time is 39 min.

[0033] The preparation method of the binder described in step (3) comprises the following steps: mixing modified corn starch, phosphate starch and water, stirring and dissolving them at 79°C for 36 minutes, then adding epichlorohydrin and continuing to stir for 24 minutes, and cooling to 31°C after vacuuming to prepare the binder.

[0034] in: The mass ratio of modified corn starch to phosphate starch is 6.5:1.

[0035] The mass of water is 2.8 times the mass of modified corn starch and phosphate starch combined.

[0036] The mass of epichlorohydrin accounts for 2.5% of the mass of modified corn starch.

[0037] The preparation method of the modified corn starch consists of the following steps: ① Mix corn starch and hydrochloric acid and stir to dissolve at 55℃ for 2.2h, then add sodium hydroxide to adjust the system to a neutral environment, raise the temperature to 70℃ and continue stirring for 40min to gelatinize; ② Cool the reaction system to 55°C, add dodecyl dimethyl betaine, styrene-acrylic acid copolymer and ammonium persulfate, then add hydrochloric acid to adjust the pH value of the reaction system to 4.5, and finally raise the temperature to 75°C to continue the reaction for 1.6 hours. After the reaction is completed, add resorcinol to terminate the reaction; ③ Sodium bicarbonate was added to adjust the pH value of the reaction system to 6.0, and modified corn starch was prepared through post-treatment.

[0038] in: In step ①, the mass volume ratio of corn starch to hydrochloric acid is 1:2.4, in g / mL.

[0039] In step ②, the mass of dodecyl dimethyl betaine accounts for 2.5% of the mass of corn starch, the mass of styrene-acrylic acid copolymer accounts for 22% of the mass of corn starch, the mass of ammonium persulfate accounts for 0.4% of the mass of corn starch, and the mass of resorcinol accounts for 3.5% of the mass of corn starch.

[0040] The post-treatment in step ③ is ethanol precipitation, distilled water washing, centrifugation, and then drying at 55° C. for 8 hours.

[0041] Example 2 The method for preparing the corrugated paper described in this embodiment 2 comprises the following steps: (1) crushing and beating larch kraft pulp, bleached acacia pulp and bleached flax pulp respectively to obtain larch kraft pulp slurry, bleached acacia pulp slurry and bleached flax pulp slurry, and then mixing the larch kraft pulp slurry, bleached acacia pulp slurry and bleached flax pulp slurry to prepare a mixed slurry; (2) adding polyamide amine and citric acid to the mixed slurry prepared in step (1) and stirring for 30 minutes, heating to 88° C. for condensation for 14 minutes, then adding styrene-butadiene emulsion and Tween-80 and stirring for 38 minutes, and finally adding polymethyl ethylene carbonate and stirring for 15 minutes to prepare base paper pulp, using a papermaking machine to prepare base paper from the base paper pulp, and preparing a corrugated paper core by corrugating the base paper; (3) The surface of the corrugated paper core is evenly coated with an adhesive, and then two pieces of base paper are respectively bonded to the upper and lower sides of the corrugated paper core, and corrugated paper is prepared by drying and baking.

[0042] in: The bleached acacia pulp in step (1) was purchased from Asia Pacific Sun Paper (Shandong) Co., Ltd., the larch kraft pulp was purchased from Nine Dragons Xingan Pulp and Paper (Inner Mongolia) Co., Ltd., and the bleached flax pulp was purchased from Mudanjiang Hengfeng Paper Co., Ltd.

[0043] In step (1), the mass ratio of larch kraft pulp, bleached acacia pulp and bleached flax pulp is 5.7:2.5:1.8.

[0044] In step (1), the beating degree of larch kraft pulp slurry is 30°SR, and the mass concentration of larch kraft pulp slurry is 4.4%; the beating degree of bleached acacia pulp slurry is 35°SR, and the mass concentration of bleached acacia pulp slurry is 5.2%; the beating degree of bleached flax pulp slurry is 25°SR, and the mass concentration of bleached flax pulp slurry is 3.5%.

[0045] In step (2), the mass of the polyamide amine accounts for 1.3% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of the styrene-butadiene emulsion accounts for 2.7% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of the polymethyl ethylene carbonate accounts for 0.8% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of Tween-80 accounts for 0.2% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; and citric acid is added to adjust the pH value of the system to 5.5.

[0046] The temperature of corrugating in step (2) is 178°C.

[0047] In step (3), the drying temperature is 45°C, the drying time is 1.2 h, the drying temperature is 108°C, and the drying time is 38 min.

[0048] The preparation method of the binder described in step (3) comprises the following steps: mixing modified corn starch, phosphate starch and water, stirring and dissolving them at 78°C for 35 minutes, then adding epichlorohydrin and continuing to stir for 25 minutes, and cooling to 33°C after vacuuming to prepare the binder.

[0049] in: The mass ratio of modified corn starch to phosphate starch is 7:1.

[0050] The mass of water is 2.8 times the mass of modified corn starch and phosphate starch combined.

[0051] The mass of epichlorohydrin accounts for 2.6% of the mass of modified corn starch.

[0052] The preparation method of the modified corn starch consists of the following steps: ① Mix corn starch and hydrochloric acid and stir to dissolve at 55℃ for 2.2h, then add sodium hydroxide to adjust the system to a neutral environment, raise the temperature to 70℃ and continue stirring for 40min to gelatinize; ② Cool the reaction system to 55°C, add dodecyl dimethyl betaine, styrene-acrylic acid copolymer and ammonium persulfate, then add hydrochloric acid to adjust the pH value of the reaction system to 4.5, and finally raise the temperature to 75°C to continue the reaction for 1.6 hours. After the reaction is completed, add resorcinol to terminate the reaction; ③ Sodium bicarbonate was added to adjust the pH value of the reaction system to 6.0, and modified corn starch was prepared through post-treatment.

[0053] in: In step ①, the mass volume ratio of corn starch to hydrochloric acid is 1:2.4, in g / mL.

[0054] In step ②, the mass of dodecyl dimethyl betaine accounts for 2.5% of the mass of corn starch, the mass of styrene-acrylic acid copolymer accounts for 22% of the mass of corn starch, the mass of ammonium persulfate accounts for 0.4% of the mass of corn starch, and the mass of resorcinol accounts for 3.5% of the mass of corn starch.

[0055] The post-treatment in step ③ is ethanol precipitation, distilled water washing, centrifugation, and then drying at 55° C. for 8 hours.

[0056] Example 3 The method for preparing the corrugated paper described in this embodiment 3 comprises the following steps: (1) crushing and beating larch kraft pulp, bleached acacia pulp and bleached flax pulp respectively to obtain larch kraft pulp slurry, bleached acacia pulp slurry and bleached flax pulp slurry, and then mixing the larch kraft pulp slurry, bleached acacia pulp slurry and bleached flax pulp slurry to prepare a mixed slurry; (2) adding polyamide amine and citric acid to the mixed slurry prepared in step (1) and stirring for 25 minutes, heating to 85° C. for condensation for 12 minutes, then adding styrene-butadiene emulsion and Tween-80 and stirring for 35 minutes, and finally adding polymethyl ethylene carbonate and stirring for 20 minutes to prepare base paper pulp, using a papermaking machine to prepare base paper from the base paper pulp, and preparing a corrugated paper core by corrugating the base paper; (3) The surface of the corrugated paper core is evenly coated with an adhesive, and then two pieces of base paper are respectively bonded to the upper and lower sides of the corrugated paper core, and corrugated paper is prepared by drying and baking.

[0057] in: The bleached acacia pulp in step (1) was purchased from Asia Pacific Sun Paper (Shandong) Co., Ltd., the larch kraft pulp was purchased from Nine Dragons Xingan Pulp and Paper (Inner Mongolia) Co., Ltd., and the bleached flax pulp was purchased from Mudanjiang Hengfeng Paper Co., Ltd.

[0058] In step (1), the mass ratio of larch kraft pulp, bleached acacia pulp and bleached flax pulp is 5.7:2.5:1.8.

[0059] In step (1), the beating degree of larch kraft pulp slurry is 30°SR, and the mass concentration of larch kraft pulp slurry is 4.4%; the beating degree of bleached acacia pulp slurry is 35°SR, and the mass concentration of bleached acacia pulp slurry is 5.2%; the beating degree of bleached flax pulp slurry is 25°SR, and the mass concentration of bleached flax pulp slurry is 3.5%.

[0060] In step (2), the mass of the polyamide amine accounts for 1.2% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of the styrene-butadiene emulsion accounts for 2.5% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of the polymethyl ethylene carbonate accounts for 1.0% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of Tween-80 accounts for 0.2% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; and citric acid is added to adjust the pH value of the system to 5.5.

[0061] The temperature of corrugating in step (2) is 175°C.

[0062] In step (3), the drying temperature is 40°C, the drying time is 1h, the drying temperature is 105°C, and the drying time is 38min.

[0063] The preparation method of the binder described in step (3) comprises the following steps: mixing modified corn starch, phosphate starch and water, stirring and dissolving them at 78°C for 35 minutes, then adding epichlorohydrin and continuing to stir for 23 minutes, and cooling to 30°C after vacuuming to prepare the binder.

[0064] in: The mass ratio of modified corn starch to phosphate starch is 6:1.

[0065] The mass of water is 2.8 times the mass of modified corn starch and phosphate starch combined.

[0066] The mass of epichlorohydrin accounts for 2.4% of the mass of modified corn starch.

[0067] The preparation method of the modified corn starch consists of the following steps: ① Mix corn starch and hydrochloric acid and stir to dissolve at 55℃ for 2.2h, then add sodium hydroxide to adjust the system to a neutral environment, raise the temperature to 70℃ and continue stirring for 40min to gelatinize; ② Cool the reaction system to 55°C, add dodecyl dimethyl betaine, styrene-acrylic acid copolymer and ammonium persulfate, then add hydrochloric acid to adjust the pH value of the reaction system to 4.5, and finally raise the temperature to 75°C to continue the reaction for 1.6 hours. After the reaction is completed, add resorcinol to terminate the reaction; ③ Sodium bicarbonate was added to adjust the pH value of the reaction system to 6.0, and modified corn starch was prepared through post-treatment.

[0068] in: In step ①, the mass volume ratio of corn starch to hydrochloric acid is 1:2.4, in g / mL.

[0069] In step ②, the mass of dodecyl dimethyl betaine accounts for 2.5% of the mass of corn starch, the mass of styrene-acrylic acid copolymer accounts for 22% of the mass of corn starch, the mass of ammonium persulfate accounts for 0.4% of the mass of corn starch, and the mass of resorcinol accounts for 3.5% of the mass of corn starch.

[0070] The post-treatment in step ③ is ethanol precipitation, distilled water washing, centrifugation, and then drying at 55° C. for 8 hours.

[0071] Comparative Example 1 The method for preparing the corrugated paper described in this comparative example 1 is the same as that in Example 1, the only difference being that in step (2), styrene-butadiene emulsion, Tween-80 and polymethyl ethylene carbonate are no longer added, and only condensation reaction is performed.

[0072] Comparative Example 2 The method for preparing the corrugated paper described in this comparative example 2 is the same as that in Example 1, with the only difference being that in step (3), when preparing the binder, modified corn starch is no longer used, but corn starch is directly used.

[0073] The corrugated paper prepared in Examples 1-3 and Comparative Examples 1-2 was subjected to performance tests, wherein the water absorption was tested according to GB / T1540-2002 "Determination of water absorption of paper and paperboard", the bursting strength was tested according to GB / T 6545-1998 "Determination of bursting strength of corrugated paperboard", the puncture strength was tested according to GB / T 2679.7-2005 "Determination of puncture strength of paperboard", and the edge compression strength was tested according to GB / T 6546-1998 "Determination of edge compression strength of corrugated paperboard". The test results are shown in Table 1 below: Table 1 Corrugated paper performance test results

Claims

1. A method for preparing corrugated paper, characterized in that: It consists of the following steps: (1) crushing and beating larch kraft pulp, bleached acacia pulp and bleached flax pulp respectively to obtain larch kraft pulp slurry, bleached acacia pulp slurry and bleached flax pulp slurry, and then mixing the larch kraft pulp slurry, bleached acacia pulp slurry and bleached flax pulp slurry to prepare a mixed slurry; (2) adding polyamide amine and citric acid to the mixed slurry prepared in step (1) and stirring for 25-30 minutes, heating to 85-88° C. for condensation for 12-14 minutes, then adding styrene-butadiene emulsion and Tween-80 and stirring for 35-38 minutes, and finally adding polymethyl ethylene carbonate and stirring for 15-20 minutes to prepare base paper pulp, using a papermaking machine to prepare base paper from the base paper pulp, and preparing a corrugated paper core by corrugating the base paper; (3) The surface of the corrugated paper core is evenly coated with an adhesive, and then two pieces of base paper are respectively bonded to the upper and lower sides of the corrugated paper core, and corrugated paper is prepared by drying and baking.

2. The method for preparing corrugated paper according to claim 1, characterized in that: In step (1), the mass ratio of larch kraft pulp, bleached acacia pulp and bleached flax pulp is 5.7:2.5:1.8; In step (1), the beating degree of larch kraft pulp slurry is 30°SR, and the mass concentration of larch kraft pulp slurry is 4.4%; the beating degree of bleached acacia pulp slurry is 35°SR, and the mass concentration of bleached acacia pulp slurry is 5.2%; the beating degree of bleached flax pulp slurry is 25°SR, and the mass concentration of bleached flax pulp slurry is 3.5%.

3. The method for preparing corrugated paper according to claim 1, characterized in that: In step (2), the mass of the polyamide amine accounts for 1.2-1.3% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of the styrene-butadiene emulsion accounts for 2.5-2.7% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of the polymethyl ethylene carbonate accounts for 0.8-1.0% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; the mass of Tween-80 accounts for 0.2% of the total mass of larch kraft pulp, bleached acacia pulp and bleached flax pulp; and citric acid is added to adjust the pH value of the system to 5.

5.

4. The method for preparing corrugated paper according to claim 1, characterized in that: The temperature of corrugating in step (2) is 175-178°C.

5. The method for preparing corrugated paper according to claim 1, characterized in that: In step (3), the drying temperature is 40-45°C, the drying time is 1-1.2h, the drying temperature is 105-108°C, and the drying time is 38-40min.

6. The method for preparing corrugated paper according to claim 1, characterized in that: The preparation method of the binder in step (3) comprises the following steps: mixing modified corn starch, phosphate starch and water, stirring and dissolving at 78-80°C for 35-38 minutes, then adding epichlorohydrin and continuing stirring for 23-25 ​​minutes, and cooling to 30-33°C after vacuuming to prepare the binder.

7. The method for preparing corrugated paper according to claim 6, characterized in that: The mass ratio of modified corn starch to phosphate starch is 6-7:1; The mass of water is 2.8 times the mass of modified corn starch and phosphate starch combined; The mass of epichlorohydrin accounts for 2.4-2.6% of the mass of modified corn starch.

8. The method for preparing corrugated paper according to claim 6, characterized in that: The preparation method of the modified corn starch consists of the following steps: ① Mix corn starch and hydrochloric acid and stir to dissolve at 55℃ for 2.2h, then add sodium hydroxide to adjust the system to a neutral environment, raise the temperature to 70℃ and continue stirring for 40min to gelatinize; ② Cool the reaction system to 55°C, add dodecyl dimethyl betaine, styrene-acrylic acid copolymer and ammonium persulfate, then add hydrochloric acid to adjust the pH value of the reaction system to 4.5, and finally raise the temperature to 75°C to continue the reaction for 1.6 hours. After the reaction is completed, add resorcinol to terminate the reaction; ③ Sodium bicarbonate was added to adjust the pH value of the reaction system to 6.0, and modified corn starch was prepared through post-treatment.

9. The method for preparing corrugated paper according to claim 8, characterized in that: In step ①, the mass volume ratio of corn starch to hydrochloric acid is 1:2.4, in g / mL; In step ②, the mass of dodecyl dimethyl betaine accounts for 2.5% of the mass of corn starch, the mass of styrene-acrylic acid copolymer accounts for 22% of the mass of corn starch, the mass of ammonium persulfate accounts for 0.4% of the mass of corn starch, and the mass of resorcinol accounts for 3.5% of the mass of corn starch.

10. The method for preparing corrugated paper according to claim 8, characterized in that: The post-treatment in step ③ is ethanol precipitation, distilled water washing, centrifugation, and then drying at 55° C. for 8 hours.

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