Preparation method of high-toughness impact-resistant box plate anti-collision appearance package

Abstract

The invention discloses a preparation method of a high-toughness impact-resistant box plate anti-collision appearance package, and particularly relates to the technical field of high-performance plant fiber composites.According to the package, bleached softwood and hardwood pulp are used as substrates, modified aramid pulp is introduced for reinforcement, and carboxylated butyronitrile latex and nano-zinc oxide are used for preparing pre-crosslinking toughening emulsion. After wet molding, the composite material is prepared by adopting a gradient variable-temperature hot-pressing process of pre-hot-pressing dehydration, high-temperature plasticizing crosslinking and cold-pressing surface finishing. According to the invention, an'ion coordination-covalent bond 'dual network and a dynamic sacrifice bond mechanism are constructed, energy is dissipated through chemical bond breakage when the material is impacted, and the toughness and collision resistance of the material are remarkably improved in cooperation with the microcosmic bridging effect of the aramid pulp, so that the defect of high brittleness of a traditional paperboard is overcome. And meanwhile, gradient hot pressing endows the packaging surface with high-density and high-gloss plastic-like texture, and unification of functions and appearance is achieved.

Description

Technical Field

[0001] This invention relates to the field of high-performance plant fiber composite materials technology, and in particular to a method for preparing a high-toughness, impact-resistant, and anti-collision packaging box. Background Technology

[0002] With the rapid development of modern logistics and premium e-commerce, the demand for packaging for high-end electronic products, cosmetics, and precision instruments is increasing daily. This type of packaging not only plays a crucial role in protecting the contents from damage caused by drops and collisions during transportation, but also serves as a key medium for showcasing brand image and enhancing the user's unboxing experience. Driven by the "plastic ban" and global green environmental trends, paper-based packaging materials made from plant fibers are gradually replacing traditional EPS foam (polystyrene) and EVA foam materials due to their biodegradable and recyclable properties, becoming the preferred solution for high-end impact-resistant packaging. In particular, box-type packaging with excellent appearance and high strength has become a hot topic in industry research and development.

[0003] Currently, paper-based shockproof packaging mainly falls into two categories: one is traditional corrugated cardboard or grey-backed white cardboard, which provides rigidity and compressive strength through multi-layer composites or structural designs (such as folded cushioning structures); the other is plant fiber molding (commonly known as pulp molding), which is made into a three-dimensional lining or outer shell through wet molding and hot-pressing drying. To achieve a high-end appearance, existing high-end gift boxes typically use high-grammage grey cardboard as the skeleton, with coated paper or specialty paper laminated to the surface for exquisite printing and tactile feel. To improve the strength of the cardboard, existing technologies mostly employ physical methods such as increasing the beating degree, adding conventional reinforcing agents (such as starch, conventional polyacrylamide), or increasing the cardboard thickness.

[0004] However, existing paper-based packaging materials still have significant shortcomings in balancing "high toughness and impact resistance" with "exquisite appearance." Firstly, while traditional rigid cardboard is highly rigid, it lacks toughness and exhibits significant brittleness. When subjected to the instantaneous impact of a sharp object or accidental drop, the fiber network is prone to brittle fracture or interlayer delamination, leading to damage to the packaging edges and corners or even loss of protective capabilities. Unlike plastics or rubber, it cannot dissipate energy through deformation. Secondly, while ordinary pulp molding materials possess some cushioning properties, their surfaces are often rough, prone to linting and powdering. Furthermore, achieving cushioning often sacrifices density, resulting in a soft appearance and low gloss, making it difficult to directly perform high-precision surface finishing and failing to meet the "smooth, plastic-like" texture requirements of high-end packaging. Therefore, there is an urgent need to develop a new type of packaging material that can effectively dissipate impact energy through microscopic mechanisms while also possessing a highly dense and smooth appearance. Summary of the Invention

[0005] The main objective of this invention is to provide a method for preparing a high-toughness, impact-resistant box-type packaging material. By constructing a dynamic sacrificial bond toughening network of carboxylated nitrile latex and nano zinc oxide, and combining it with a gradient hot-pressing and cold finishing process, the technical problems of poor impact resistance and rough surface texture of existing paper-based packaging materials due to their high brittleness are effectively solved.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A high-toughness, impact-resistant box-like packaging material comprises the following components in parts by weight: 600-800 parts bleached softwood sulfate pulp board, 200-300 parts bleached hardwood pulp, 100-150 parts carboxylated nitrile butadiene latex, 30-50 parts nano zinc oxide suspension with a solid content of 20%, 20-40 parts modified aramid pulp, 10-20 parts polyamide epichlorohydrin resin, 8-12 parts alkyl ketene dimer, 0.5-1 part cationic polyacrylamide, and 0.1-0.3 parts silicone defoamer.

[0007] Preferably, the anti-collision outer packaging comprises the following components in parts by weight: 700 parts of bleached softwood sulfate pulp board, 240 parts of bleached hardwood pulp, 120 parts of carboxylated nitrile latex, 40 parts of nano zinc oxide suspension with a solid content of 20%, 30 parts of modified aramid pulp, 15 parts of polyamide epichlorohydrin resin, 10 parts of alkyl ketene dimer, 0.7 parts of cationic polyacrylamide, and 0.2 parts of silicone defoamer.

[0008] A method for preparing the above-mentioned high-toughness, impact-resistant, and anti-collision outer packaging of the box panel includes the following specific steps: Step S1: Pretreatment and dissociation of fiber matrix: Mix the formulated amount of bleached softwood sulfate pulp board and bleached hardwood pulp, adjust the pulp concentration to 3%-4%, and after dissociation and refining, obtain mixed fiber pulp; Step S2: Take the formula amount of carboxylated nitrile latex and place it in a reaction vessel. Add the formula amount of nano zinc oxide suspension with a solid content of 20% while stirring. Heat the reaction to allow zinc ions to coordinate and crosslink with carboxyl groups to obtain a pre-crosslinked toughening emulsion. Step S3: Modification and mixing of fiber pulp: Adjust the concentration of the mixed fiber pulp obtained in step S1 to 1.5%-2.0%, and add the following in sequence under stirring: the modified aramid pulp, the pre-crosslinked toughening emulsion obtained in step S2, the polyamide epichlorohydrin resin, the alkyl ketene dimer, the cationic polyacrylamide, and the silicone defoamer. Mix evenly to obtain the molding pulp. Step S4: Wet forming and dewatering: The forming slurry obtained in step S3 is pumped into the headbox for wire forming. After gravity dewatering and vacuum dewatering, a wet paper web with a moisture content of 60%-70% is formed. Step S5: Gradient temperature hot-press drying: The wet paper web obtained in step S4 is subjected to preheating and dehydration, high-temperature plasticizing and cross-linking, and cold pressing and surface finishing in sequence to obtain the high-toughness and impact-resistant box board anti-collision packaging.

[0009] Preferably, in step S1, the specific process parameters for the pulping treatment are as follows: The long fiber freeness of bleached softwood sulfate pulp board is controlled at 35-40°SR, and the short fiber freeness of bleached hardwood pulp is controlled at 40-45°SR.

[0010] Preferably, the preparation conditions for the pre-crosslinked toughening emulsion are as follows: The stirring speed is controlled at 800-1000 rpm. After the addition is complete, the temperature is raised to 50-60℃ and the reaction is carried out with stirring for 30 minutes.

[0011] Preferably, the specific mixing process of the molding slurry is as follows: First, add the modified aramid pulp and disperse it for 10 minutes under low-speed stirring at 200-300 rpm; then add the pre-crosslinked toughening emulsion and stir for 15-20 minutes to allow the elastomer to coat the fiber and aramid pulp; finally, add the remaining additives in sequence and stir evenly.

[0012] Preferably, the gradient temperature hot-press drying specifically includes the following three stages: The first stage is the preheating and pressing section: the temperature is controlled at 90-105℃, the pressure is 1.0-1.5 MPa, and the hot pressing time is 20-30 seconds; The second stage is the high-temperature plasticizing section: the temperature is controlled at 130-145℃, the pressure is 3.0-4.0 MPa, and the hot pressing time is 60-90 seconds; The third stage is the surface finishing stage: the temperature is controlled at 20-25℃ and the pressure is 5.0-6.0 MPa for cold pressing.

[0013] Preferably, in the second stage high-temperature plasticizing section, the carboxylated nitrile latex melts and flows to fill the fiber gaps, and the ion coordination network of the nano zinc oxide and the carboxylated nitrile latex is completely cured; in the third stage surface finishing section, a dense layer and high gloss are imparted to the packaging surface through high-pressure cold finishing.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention successfully constructs a dual network structure of "ion coordination-covalent bonds" at the microscopic level by introducing carboxylated nitrile latex and nano-zinc oxide into the plant fiber skeleton. When the packaging material is subjected to strong external impacts such as drops or collisions, the ion coordination bonds distributed between the molecular chains, acting as "sacrificial bonds," will preferentially break, thereby dissipating a large amount of impact kinetic energy and effectively protecting the main fiber skeleton from breakage. Simultaneously, the "microscopic bridging" and crack-resistant effect of modified aramid pulp in the fiber network endows the packaging material with excellent toughness and resilience similar to an elastomer, fundamentally solving the problems of high brittleness, easy cracking upon impact, and interlayer delamination caused by the excessive hardness of traditional high-strength cardboard.

[0015] 2. This invention innovatively employs a gradient manufacturing process of "high-temperature plasticizing – cold-press finishing." During the high-temperature plasticizing stage, the elastomer latex melts and flows, fully filling the tiny gaps between fibers and eliminating internal material defects. The subsequent high-pressure cold finishing step rapidly "freezes" and solidifies the dense surface layer structure. This process results in packaging boards with extremely high surface smoothness and a strong gloss, exhibiting a delicate, plastic-like texture. It effectively overcomes the common problems of rough, porous, and easily shedding lint and powder found in traditional pulp molding or fiber packaging, greatly improving the printing adaptability and appearance of the packaging, and meeting the stringent requirements of high-end packaging. Detailed Implementation

[0016] To more clearly illustrate the technical solutions of the embodiments in this specification, a brief description of the embodiments will be provided below. Obviously, the following description is merely some examples or embodiments of this specification. For those skilled in the art, this specification can be applied to other similar scenarios without creative effort. Unless it is obvious from the linguistic context or otherwise stated.

[0017] This invention discloses a high-toughness, impact-resistant box-type packaging material, comprising the following components in parts by weight: 600-800 parts of bleached softwood sulfate pulp board, 200-300 parts of bleached hardwood pulp, 100-150 parts of carboxylated nitrile latex, 30-50 parts of nano-zinc oxide suspension with a solid content of 20%, 20-40 parts of modified aramid pulp, 10-20 parts of polyamide epichlorohydrin resin, 8-12 parts of alkyl ketene dimer, 0.5-1 part of cationic polyacrylamide, and 0.1-0.3 parts of silicone defoamer.

[0018] The present invention is further disclosed below with reference to embodiments: Example 1 In this embodiment, the anti-collision packaging comprises the following components in parts by weight: 700 parts of bleached softwood sulfate pulp board, 240 parts of bleached hardwood pulp, 120 parts of carboxylated nitrile latex, 40 parts of nano zinc oxide suspension with a solid content of 20%, 30 parts of modified aramid pulp, 15 parts of polyamide epichlorohydrin resin, 10 parts of alkyl ketene dimer, 0.7 parts of cationic polyacrylamide, and 0.2 parts of silicone defoamer.

[0019] This embodiment prepares the impact-resistant outer packaging as follows: Step S1: Pretreatment and dissociation of fiber matrix: Mix the formulated amounts of bleached softwood sulfate pulp board and bleached hardwood pulp, adjust the pulp concentration to 3%-4%, and after dissociation and refining, obtain mixed fiber pulp; wherein, the specific process parameters of the refining process are: control the freeness of the long fibers of the bleached softwood sulfate pulp board to 35-40°SR, and control the freeness of the short fibers of the bleached hardwood pulp to 40-45°SR; Step S2: Take the prescribed amount of carboxylated nitrile latex and place it in a reaction vessel. Add the prescribed amount of nano zinc oxide suspension with a solid content of 20% dropwise while stirring. Heat the mixture to allow zinc ions to coordinate and crosslink with carboxyl groups, thus obtaining a pre-crosslinked toughening emulsion. The preparation conditions for the pre-crosslinked toughening emulsion are as follows: the stirring speed is controlled at 800-1000 rpm, and after the dropwise addition is completed, the temperature is raised to 50-60℃ and the mixture is kept at this temperature and stirred for 30 minutes. Step S3: Modification and mixing of fiber pulp: Adjust the concentration of the mixed fiber pulp obtained in step S1 to 1.5%-2.0%, and add the following in sequence under stirring: the modified aramid pulp, the pre-crosslinked toughening emulsion obtained in step S2, the polyamide epichlorohydrin resin, the alkyl ketene dimer, the cationic polyacrylamide, and the silicone defoamer. Mix evenly to obtain the molding pulp. The specific mixing process for the molding slurry is as follows: First, add the modified aramid pulp and disperse it for 10 minutes under low-speed stirring at 200-300 rpm; then add the pre-crosslinked toughening emulsion and stir for 15-20 minutes to allow the elastomer to coat the fiber and aramid pulp; finally, add the remaining auxiliaries in sequence and stir evenly. Step S4: Wet forming and dewatering: The forming slurry obtained in step S3 is pumped into the headbox for wire forming. After gravity dewatering and vacuum dewatering, a wet paper web with a moisture content of 60%-70% is formed. Step S5: Gradient temperature hot-press drying: The wet paper web obtained in step S4 is subjected to preheating and dehydration, high-temperature plasticizing and cross-linking, and cold pressing and surface finishing in sequence to obtain the high-toughness and impact-resistant box board anti-collision packaging.

[0020] The gradient temperature hot-press drying process specifically includes the following three stages: The first stage is the preheating and pressing section: the temperature is controlled at 90-105℃, the pressure is 1.0-1.5 MPa, and the hot pressing time is 20-30 seconds; The second stage is the high-temperature plasticizing section: the temperature is controlled at 130-145℃, the pressure is 3.0-4.0 MPa, and the hot pressing time is 60-90 seconds; in the second stage high-temperature plasticizing section, the carboxylated nitrile latex melts and flows to fill the fiber gaps, and the ion coordination network of the nano zinc oxide and the carboxylated nitrile latex is completely cured; in the third stage surface finishing section, a dense layer and high gloss are given to the packaging surface through high-pressure cold finishing.

[0021] The third stage is the surface finishing stage: the temperature is controlled at 20-25℃ and the pressure is 5.0-6.0 MPa for cold pressing.

[0022] Example 2 The similarities between this embodiment and Embodiment 1 will not be repeated here. The differences between this embodiment and Embodiment 1 are as follows: The impact-resistant outer packaging comprises the following components in parts by weight: 600 parts bleached softwood sulfate pulp board, 200 parts bleached hardwood pulp, 100 parts carboxylated nitrile latex, 30 parts nano zinc oxide suspension with 20% solid content, 20 parts modified aramid pulp, 10 parts polyamide epichlorohydrin resin, 8 parts alkyl ketene dimer, 0.5 parts cationic polyacrylamide, and 0.1 parts silicone defoamer.

[0023] Example 3 The similarities between this embodiment and Embodiment 1 will not be repeated here. The differences between this embodiment and Embodiment 1 are as follows: The impact-resistant outer packaging comprises the following components in parts by weight: 800 parts bleached softwood sulfate pulp board, 300 parts bleached hardwood pulp, 150 parts carboxylated nitrile latex, 50 parts nano zinc oxide suspension with 20% solid content, 40 parts modified aramid pulp, 20 parts polyamide epichlorohydrin resin, 12 parts alkyl ketene dimer, 1 part cationic polyacrylamide, and 0.3 parts silicone defoamer.

[0024] Example 4 The similarities between this embodiment and Embodiment 1 will not be repeated here. The differences between this embodiment and Embodiment 1 are as follows: The impact-resistant outer packaging comprises the following components in parts by weight: 650 parts bleached softwood sulfate pulp board, 220 parts bleached hardwood pulp, 110 parts carboxylated nitrile latex, 35 parts nano zinc oxide suspension with 20% solid content, 25 parts modified aramid pulp, 13 parts polyamide epichlorohydrin resin, 9 parts alkyl ketene dimer, 0.7 parts cationic polyacrylamide, and 0.2 parts silicone defoamer.

[0025] Example 5 The similarities between this embodiment and Embodiment 1 will not be repeated here. The differences between this embodiment and Embodiment 1 are as follows: The impact-resistant outer packaging comprises the following components in parts by weight: 750 parts bleached softwood sulfate pulp board, 290 parts bleached hardwood pulp, 140 parts carboxylated nitrile latex, 45 parts nano zinc oxide suspension with 20% solid content, 35 parts modified aramid pulp, 18 parts polyamide epichlorohydrin resin, 11 parts alkyl ketene dimer, 0.8 parts cationic polyacrylamide, and 0.2 parts silicone defoamer.

[0026] Comparative Example 1 The similarities between this comparative example and Example 1 will not be repeated here. The differences between this comparative example and Example 1 are as follows: The raw material composition did not include a nano zinc oxide suspension with a solid content of 20%.

[0027] In its specific preparation method, step S2 is omitted, and the carboxylated nitrile latex of the formula amount is directly added in step S3; The specific steps are as follows: Step S1: Same as in Example 1; Step S2: (Cancel this step); Step S3: Modification and mixing of fiber pulp: Adjust the concentration of the mixed fiber pulp obtained in step S1 to 1.5%-2.0%, and add the following in sequence under stirring: modified aramid pulp, carboxylated nitrile latex, polyamide epichlorohydrin resin, alkyl ketene dimer, cationic polyacrylamide, and silicone defoamer in the specified amounts. Mix evenly to obtain the molding pulp. The specific mixing process of the molding slurry is as follows: First, add the modified aramid slurry and disperse it for 10 minutes under low-speed stirring at 200-300 rpm; then add the carboxylated nitrile latex and stir for 15-20 minutes; finally, add the remaining additives in sequence and stir evenly. Steps S4-S5: Same as in Example 1.

[0028] Comparative Example 2 The raw material components and their weight parts in this comparative example are exactly the same as those in Example 1. The difference between this comparative example and Example 1 is that the preparation process sequence is different, and the pre-reaction of latex and nano zinc oxide is not carried out.

[0029] The specific steps are as follows: Step S1: Same as in Example 1; Step S2: (Cancel this step); Step S3: Modification and mixing of fiber slurry: Adjust the concentration of the mixed fiber slurry obtained in step S1 to 1.5%-2.0%, and add the following in sequence under stirring: modified aramid pulp, carboxylated nitrile latex, nano zinc oxide suspension with 20% solid content, polyamide epichlorohydrin resin, alkyl ketene dimer, cationic polyacrylamide, and organosilicon defoamer. Mix evenly to obtain the molding slurry. The specific mixing process of the molding slurry is as follows: First, add the modified aramid slurry and disperse it for 10 minutes under low-speed stirring at 200-300 rpm; then add the carboxylated nitrile latex and nano zinc oxide suspension at the same time and stir for 15-20 minutes; finally, add the remaining additives in sequence and stir evenly. Steps S4-S5: Same as in Example 1.

[0030] Performance Testing and Results Analysis To verify the performance of the high-toughness, impact-resistant box board for anti-collision packaging described in this invention, the finished boards prepared in Examples 1-5 and Comparative Examples 1-2 were subjected to performance testing.

[0031] 1. Testing Standards and Methods: Tensile index (N·m / g): Tested in accordance with GB / T 12914-2018 "Determination of tensile strength of paper and paperboard".

[0032] Impact strength (kJ / m²): Refer to GB / T 21189-2007 "Inspection of pendulum impact testing machine for simply supported beams, cantilever beams and tensile impact tests of plastics". The ability of the material to absorb impact energy is tested using the simply supported beam impact test mode. This index best reflects the impact resistance performance.

[0033] Folding endurance (number of double folds): Tested according to the Schubert method in GB / T 457-2008 "Determination of folding endurance of paper and paperboard", reflecting the toughness and fatigue resistance of the material.

[0034] Surface smoothness (s): Tested according to GB / T 456-2002 "Determination of smoothness of paper and paperboard (Burke method)". The higher the value, the smoother and denser the surface and the better the appearance.

[0035] 2. Test Result Statistics Table: 3. Analysis of Experimental Results: As can be seen from the data in the table above, the anti-collision packaging prepared using the technical solutions of the present invention (Examples 1-5) all exhibit excellent mechanical properties and appearance quality.

[0036] (1) Verification of the sacrificial bond toughening mechanism (Example 1 vs. Comparative Example 1): The impact strength of Example 1 is as high as 18.5 kJ / m², while that of Comparative Example 1 (without nano zinc oxide) is only 8.2 kJ / m², a performance decrease of more than 55%. At the same time, the folding endurance of Comparative Example 1 also decreased significantly. This fully demonstrates that the ionic coordination bonds (sacrificial bonds) formed by "nano zinc oxide and carboxylated nitrile latex" in this invention play a key role in energy dissipation when subjected to impact. Without this micro-network, the material only exhibits the performance of ordinary latex-filled cardboard and cannot resist high-intensity impacts.

[0037] (2) Verification of the necessity of the pre-crosslinking process (Example 1 vs. Comparative Example 2): The formulations of Example 1 and Comparative Example 2 are exactly the same, the only difference being that Comparative Example 2 did not undergo the "pre-crosslinking reaction" in step S2, but was directly mixed. Data shows that the impact strength of Comparative Example 2 (12.4 kJ / m²) is significantly lower than that of Example 1. This indicates that simple physical mixing cannot allow zinc ions to form a uniform and stable crosslinking network with latex carboxyl groups, and some nano-zinc oxide may be lost or exist as an inert filler, failing to exert its maximum toughening effect. This also conversely proves the inventiveness and necessity of the process step S2 of this invention.

[0038] (3) Appearance performance analysis: The smoothness of the example group was all above 380s. This is because the high-temperature plasticizing stage in the gradient hot pressing process allowed the cross-linked latex system to fully fill the fiber gaps and form a dense surface layer in the cold finishing stage. However, due to the lack of an ionic cross-linking network, the latex in Comparative Example 1 had good fluidity during hot pressing but poor cohesion, which easily led to excessive penetration or sticking to the rollers, resulting in a surface smoothness that was not as good as that of the example group that had constructed a stable network.

[0039] In summary, the packaging material prepared by this invention achieves a combination of high toughness, high impact resistance, and excellent appearance, which is far superior to existing conventional modification techniques.

[0040] It should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be consistent with the teachings of this specification, rather than as examples or limitations. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

Claims

1. A high-toughness, impact-resistant box-like packaging material, characterized in that, The impact-resistant outer packaging comprises the following components in parts by weight: 600-800 parts bleached softwood sulfate pulp board, 200-300 parts bleached hardwood pulp, 100-150 parts carboxylated nitrile latex, 30-50 parts nano zinc oxide suspension with 20% solid content, 20-40 parts modified aramid pulp, 10-20 parts polyamide epichlorohydrin resin, 8-12 parts alkyl ketene dimer, 0.5-1 part cationic polyacrylamide, and 0.1-0.3 parts silicone defoamer.

2. The high-toughness, impact-resistant box-type protective packaging according to claim 1, characterized in that, The impact-resistant outer packaging comprises the following components in parts by weight: 700 parts bleached softwood sulfate pulp board, 240 parts bleached hardwood pulp, 120 parts carboxylated nitrile latex, 40 parts nano zinc oxide suspension with 20% solid content, 30 parts modified aramid pulp, 15 parts polyamide epichlorohydrin resin, 10 parts alkyl ketene dimer, 0.7 parts cationic polyacrylamide, and 0.2 parts silicone defoamer.

3. A method for preparing the high-toughness, impact-resistant, and anti-collision outer packaging of any one of claims 1-2, characterized in that, The specific steps are as follows: Step S1: Pretreatment and dissociation of fiber matrix: Mix the formulated amount of bleached softwood sulfate pulp board and bleached hardwood pulp, adjust the pulp concentration to 3%-4%, and after dissociation and refining, obtain mixed fiber pulp; Step S2: Take the formula amount of carboxylated nitrile latex and place it in a reaction vessel. Add the formula amount of nano zinc oxide suspension with a solid content of 20% while stirring. Heat the reaction to allow zinc ions to coordinate and crosslink with carboxyl groups to obtain a pre-crosslinked toughening emulsion. Step S3: Modification and mixing of fiber pulp: Adjust the concentration of the mixed fiber pulp obtained in step S1 to 1.5%-2.0%, and add the following in sequence under stirring: the modified aramid pulp, the pre-crosslinked toughening emulsion obtained in step S2, the polyamide epichlorohydrin resin, the alkyl ketene dimer, the cationic polyacrylamide, and the silicone defoamer. Mix evenly to obtain the molding pulp. Step S4: Wet forming and dewatering: The forming slurry obtained in step S3 is pumped into the headbox for wire forming. After gravity dewatering and vacuum dewatering, a wet paper web with a moisture content of 60%-70% is formed. Step S5: Gradient temperature hot-press drying: The wet paper web obtained in step S4 is subjected to preheating and dehydration, high-temperature plasticizing and cross-linking, and cold pressing and surface finishing in sequence to obtain the high-toughness and impact-resistant box board anti-collision packaging.

4. The method for preparing a high-toughness, impact-resistant box-type anti-collision packaging according to claim 3, characterized in that, In step S1, the specific process parameters for the pulping treatment are as follows: The long fiber freeness of bleached softwood sulfate pulp board is controlled at 35-40°SR, and the short fiber freeness of bleached hardwood pulp is controlled at 40-45°SR.

5. The method for preparing a high-toughness, impact-resistant box-type anti-collision packaging according to claim 3, characterized in that, The preparation conditions for the pre-crosslinked toughening emulsion are as follows: The stirring speed is controlled at 800-1000 rpm. After the addition is complete, the temperature is raised to 50-60℃ and the reaction is carried out with stirring for 30 minutes.

6. The method for preparing a high-toughness, impact-resistant box-type anti-collision packaging according to claim 3, characterized in that, The specific mixing process of the molding slurry is as follows: First, add the modified aramid pulp and disperse it for 10 minutes under low-speed stirring at 200-300 rpm; then add the pre-crosslinked toughening emulsion and stir for 15-20 minutes to allow the elastomer to coat the fiber and aramid pulp; finally, add the remaining additives in sequence and stir evenly.

7. The method for preparing a high-toughness, impact-resistant box-type anti-collision packaging according to claim 3, characterized in that, The gradient temperature variable-temperature hot-press drying specifically includes the following three stages: The first stage is the preheating and pressing section: the temperature is controlled at 90-105℃, the pressure is 1.0-1.5 MPa, and the hot pressing time is 20-30 seconds; The second stage is the high-temperature plasticizing section: the temperature is controlled at 130-145℃, the pressure is 3.0-4.0 MPa, and the hot pressing time is 60-90 seconds; The third stage is the surface finishing stage: the temperature is controlled at 20-25℃ and the pressure is 5.0-6.0 MPa for cold pressing.

8. The method for preparing a high-toughness, impact-resistant box-type anti-collision packaging according to claim 7, characterized in that, In the second stage high-temperature plasticizing section, the carboxylated nitrile latex melts and flows to fill the fiber gaps, and the ion coordination network of the nano zinc oxide and the carboxylated nitrile latex is completely cured; in the third stage surface finishing section, a dense layer and high gloss are imparted to the packaging surface through high-pressure cold finishing.

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