Moisture-proof and pressure-resistant packaging carton and preparation method thereof

Abstract

The invention discloses a moisture-proof and pressure-resistant packaging paper box and a preparation method thereof, relating to the technical field of packaging paper boxes. The moisture-proof and pressure-resistant packaging paper box structure is sequentially provided with an outer lining, a corrugated core paperboard, and an inner lining from top to bottom, wherein the outer lining, the corrugated core paperboard, and the inner lining are bonded by polyvinyl alcohol; prototype paper is immersed in a carboxymethyl cellulose aqueous solution, taken out and respectively immersed in copper sulfate and aluminum chloride metal ion solutions, and hot pressed to obtain inner lining and outer lining prototype paper; polyethyleneimine and methanol are added to deionized water, stirred evenly, the outer lining prototype paper is immersed in the deionized water, heated to 35-36°C for insulation, the outer lining prototype paper is taken out and immersed in solution A, glutaraldehyde is added, reacted at 25-30°C, taken out and vacuum dried for 30-45 minutes, solution B is coated on the surface of the outer lining prototype paper, and vacuum dried to obtain the outer lining.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging cartons, in particular to a moisture-proof and pressure-resistant packaging cartons and a preparation method thereof. Background Art

[0002] With growing environmental awareness and the demand for sustainable development in the packaging industry, traditional carton materials face challenges with insufficient performance in various environmental conditions, particularly in humid environments. The compressive strength and moisture resistance of packaging materials are key factors affecting the quality and service life of cartons. Traditional paper packaging materials, due to their high hygroscopicity, are susceptible to performance degradation in humid environments, resulting in reduced compressive strength and compromising the safe transportation and storage of goods.

[0003] Therefore, developing innovative packaging materials with excellent mechanical properties and moisture-proof properties has become a technical problem that needs to be solved urgently in the packaging industry. Summary of the Invention

[0004] The object of the present invention is to provide a moisture-proof and pressure-resistant packaging carton and a preparation method thereof, so as to solve the problems raised in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A moisture-proof and pressure-resistant packaging carton, wherein the moisture-proof and pressure-resistant packaging carton structure is sequentially provided with an outer lining, a corrugated core paperboard, and an inner lining from top to bottom, and the outer lining, the corrugated core paperboard, and the inner lining are bonded together by polyvinyl alcohol;

[0007] Furthermore, the preparation method of the lining includes the following steps: soaking the prototype paper in a 1-1.5wt% carboxymethyl cellulose aqueous solution for 30-45 minutes, taking it out and soaking it in a metal ion solution for 3-4 hours, and hot pressing it at 10-12MPa and 120-125°C for 6-6.5 hours to obtain the lining.

[0008] Furthermore, the preparation method of the outer lining includes the following steps: soaking the prototype paper in a 1-1.5wt% carboxymethyl cellulose aqueous solution for 30-45 minutes, taking it out and soaking it in a metal ion solution for 3-4 hours, 10-12MPa, 120-125℃ hot pressing for 6-6.5 hours to obtain the outer lining prototype paper; adding polyethyleneimine and methanol to deionized water, stirring evenly, soaking the outer lining prototype paper therein, heating it to 35-36℃ and keeping it warm for 1-1.5 hours, taking out the outer lining prototype paper and soaking it in solution A, adding glutaraldehyde, reacting under weak acid conditions at 25-30℃ for 1-1.5 hours, taking it out and vacuum drying it at 60-65℃ for 30-45 minutes, coating solution B on its surface, and vacuum drying it at 50-55℃ for 30-45 minutes to obtain the outer lining.

[0009] Furthermore, during the preparation of the inner lining, the metal ion solution is a 0.2-0.3 mol / L copper sulfate solution; during the preparation of the outer lining prototype paper, the metal ion solution is a 0.2-0.3 mol / L aluminum chloride solution; during the preparation of the outer lining, the amount of polyethyleneimine added is 0.2-0.5 wt%, and the coating thickness of solution B is 8-20 μm.

[0010] Furthermore, the preparation method of the prototype paper includes the following steps: crushing recycled cardboard boxes and adding them to water, adding 1% w / v sodium hydroxide solution, heating to 60-62°C and reacting at a consistency of 10-12wt% for 20-30 minutes, centrifuging to a consistency of 25-26wt%, and sealing and storing at 4-5°C to obtain pulp A; adding modified cellulose nanofibers, cationic starch, and colloidal silica to pulp A, stirring for 30-45 minutes to obtain pulp B; adding sodium carboxymethyl cellulose and calcium chloride to 1.5-2wt% pulp B, stirring for 15-20 minutes to obtain pulp C; adding polyethyleneimine to pulp C, stirring evenly, and forming paper to obtain prototype paper.

[0011] Furthermore, during the preparation of pulp B, the amount of modified sodium cellulose added is 3-4wt%, the amount of cationic starch added is 0.5-0.6wt%, and the amount of colloidal silicon dioxide added is 0.8-1wt%; during the preparation of pulp A, the amount of sodium carboxymethyl cellulose added is 2.5-7.5wt%, and the amount of calcium chloride added is 0.9-1wt%; during the preparation of prototype paper, the amount of polyethyleneimine added is 0.1-0.3wt%, and the basis weight is 120-180g / m 2 .

[0012] Furthermore, the preparation method of the modified cellulose nanofiber includes the following steps: dispersing bleached hardwood kraft pulp in water at a concentration of 1.5-2wt%, stirring and pulping for 30-45 minutes, filtering until the concentration of the bleached hardwood kraft pulp in water is 10-12wt%, stirring and expanding for 10-15 minutes, adding water to the concentration of the bleached hardwood kraft pulp in water to 5-5.5wt%, adding 0.1N hydrochloric acid solution to adjust the pH of the dispersion to 4.8-4.9, heating to 50-52°C, adding an enzyme mixture under stirring, keeping the temperature for hydrolysis reaction for 4-4.5 hours, heating to 80-82°C and keeping the temperature for 30-35 minutes, washing the enzyme-hydrolyzed pulp with ultrapure water, dispersing the washed pulp in water at a consistency of 1-1.2wt%, and homogenizing at 4-5°C to obtain modified cellulose nanofiber.

[0013] Furthermore, the enzyme mixture is added in an amount of 320 g / Tn.

[0014] Furthermore, the preparation method of the solution A comprises the following steps: adding carboxymethyl cellulose to deionized water, heating to 60-62° C. and stirring for 30-35 minutes, adding collagen fibers, cooling to 50-52° C. and stirring for 1-1.5 hours, and ultrasonically treating for 20-30 minutes to obtain solution A.

[0015] Furthermore, during the preparation of the solution A, the amount of carboxymethyl cellulose added is 2-3 wt %, and the amount of collagen fiber added is 2-10 wt %.

[0016] Furthermore, the preparation method of the solution B comprises the following steps: adding polyvinyl alcohol to deionized water, heating to 70-72° C. and stirring for 30-34 minutes, adding sodium tetraborate decahydrate, and stirring at this temperature for 30-35 minutes to obtain solution B.

[0017] Furthermore, during the preparation of the solution B, the amount of polyvinyl alcohol added is 2-10 wt %, and the amount of sodium tetraborate decahydrate added is 1.5-2 wt % of the mass of the polyvinyl alcohol.

[0018] A method for preparing a moisture-proof and pressure-resistant packaging carton comprises the following steps: coating both sides of a corrugated core paperboard with polyvinyl alcohol, adhering an inner liner and an outer liner to the upper and lower sides of the corrugated core paperboard, and drying to obtain moisture-proof and pressure-resistant packaging paper; and preparing the moisture-proof and pressure-resistant packaging carton according to carton specifications.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention uses bleached kraft hardwood pulp to prepare modified cellulose nanofibers through enzymatic hydrolysis; prototype paper is prepared by adding modified cellulose nanofibers and sodium carboxymethyl cellulose to the pulp, with the purpose of enhancing the mechanical properties of the paper without damaging the structure of the fiber. Hydrogen bonds and van der Waals forces in the modified cellulose nanofibers, as well as the interaction between the carboxyl groups on the surface of sodium carboxymethyl cellulose and the modified cellulose nanofibers and fibers. By adding calcium chloride, calcium chloride can be used as an ionic linker to promote this interaction. Similar effects have been observed previously in other surface chains and molecules containing carboxyl groups, such as sodium / calcium alginate for heavy metal encapsulation. Especially in the presence of calcium chloride, the reinforcement mechanism of the modified cellulose nanofibers should also take this into account. Although the COO of the modified cellulose nanofibers - The surface density is lower than that of sodium carboxymethyl cellulose, but Ca 2+ Cationic bonding improves the bonding between nanostructured fibers and paperboard fibers. Due to the increase in interfiber bonding, the internal bonding of paper is significantly improved, greatly improving the mechanical properties of the carton.

[0021] 2. Based on the prototype paper, a carboxymethyl cellulose-metal ion cross-linked network is added to its surface and internal components to further enhance the prototype paper's mechanical and waterproof properties. CMC fills the voids within the OCC paper to form a denser structure. Simultaneously, the interpenetrating hydrogen bond network between the CMC molecular chains and the OCC fibers imparts excellent mechanical properties. A metal coordination strategy is employed to enhance the water resistance of the OCC-CMC paper. After filling and hot pressing, the interlayer pores within the OCC paper are eliminated, resulting in a denser structure and significantly improving the mechanical and moisture-proof properties of the carton.

[0022] 3. Different from the inner lining and outer lining, the inner lining uses copper sulfate as the metal coordination to form a cross-linked network in order to improve the mildew resistance inside the carton. The cross-linked network of copper ion metal coordination has excellent antibacterial properties and can effectively reduce the production of mold in humid environments, thereby increasing the service life and application scenarios of the carton. However, the cross-linked network formed by it has low strength and is not suitable for use as an outer lining material.

[0023] 4. Finally, polyethyleneimine is used as a pretreatment, and electrostatic adsorption and the effect of Schiff base are generated through the homogeneous mixture of carboxymethyl cellulose and collagen fibers to enhance the adhesion and cross-linking degree of the coating. Polyvinyl alcohol is chemically modified with sodium tetraborate decahydrate, and the coating gives the paper excellent waterproof properties. The materials used in the present invention are completely green, environmentally friendly, and recyclable raw materials, which can meet the needs of sustainable development. DETAILED DESCRIPTION

[0024] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0025] In the following examples, bleached hardwood kraft pulp was purchased from Stora Enso; corrugated core board specifications: Nine Dragons corrugated board was purchased from Nine Dragons Paper Co., Ltd.; enzyme mixture model: Novozyme 476, specification: containing 2% β-1,4-endoglucanase; sodium carboxymethyl cellulose specification: degree of substitution 0.7; cationic starch CAS: 56780-58-6; colloidal silicon dioxide CAS: 10279-57-9;

[0026] The invention discloses a method for preparing modified cellulose nanofibers, comprising the following steps: dispersing bleached hardwood kraft pulp in water at a concentration of 1.5wt%, stirring and pulping for 30 minutes, filtering until the concentration of the bleached hardwood kraft pulp in water is 10wt%, stirring and expanding for 10 minutes, adding water until the concentration of the bleached hardwood kraft pulp in water is 5wt%, adding 0.1N hydrochloric acid solution to adjust the pH of the dispersion to 4.8, heating to 50°C, adding an enzyme mixture under stirring, keeping the temperature for hydrolysis reaction for 4 hours, heating to 80°C and keeping the temperature for 30 minutes, washing the enzyme-hydrolyzed pulp with ultrapure water, dispersing the washed pulp in water at a consistency of 1wt%, and homogenizing at 4°C to obtain modified cellulose nanofibers.

[0027] The enzyme mixture was added in an amount of 320 g / Tn.

[0028] Example 1: A method for preparing a moisture-proof and pressure-resistant packaging carton: S1: Crush the recycled cardboard box and add it to water, add 1% w / v sodium hydroxide solution, heat to 60°C and react at a consistency of 10wt% for 25 minutes, centrifuge to a consistency of 25wt%, and seal and store at 4°C to obtain pulp A; add 3wt% modified cellulose nanofibers, 0.5wt% cationic starch, and 0.8wt% colloidal silica to pulp A and stir for 30 minutes to obtain pulp B; add 2.5wt% sodium carboxymethyl cellulose and 0.9wt% calcium chloride to 1.5wt% pulp B and stir for 15 minutes to obtain pulp C; add 0.2wt% polyethyleneimine to pulp C, stir evenly, and form paper to obtain prototype paper, wherein the basis weight is 120g / m 2 ;

[0029] S2: The prototype paper was soaked in a 1 wt% carboxymethyl cellulose aqueous solution for 30 min, then soaked in a 0.2 mol / L copper sulfate solution for 3 h, and hot-pressed at 10 MPa and 120 °C for 6 h to obtain the lining;

[0030] S3: 2 wt% carboxymethyl cellulose was added to deionized water, heated to 60°C and stirred for 30 min, 2 wt% collagen fibers were added, cooled to 50°C and stirred for 1 h, and ultrasonicated for 20 min to obtain solution A;

[0031] S4: Add 2 wt% polyvinyl alcohol to deionized water, heat to 70°C and stir for 30 min, add sodium tetraborate decahydrate, and keep stirring for 30 min to obtain solution B; the amount of sodium tetraborate decahydrate added is 1.5 wt% of the mass of polyvinyl alcohol;

[0032] S5: Soak the prototype paper in a 1wt% carboxymethyl cellulose aqueous solution for 30 minutes, take it out and soak it in a 0.2mol / L aluminum chloride solution for 3 hours, 10MPa, and hot press at 120℃ for 6 hours to obtain an outer lining prototype paper; add 2g polyethyleneimine and 100mL methanol to 500mL deionized water, stir evenly, soak the outer lining prototype paper therein, heat to 35℃ and keep warm for 1 hour, take out the outer lining prototype paper and soak it in solution A, add 10mL glutaraldehyde, react at 25℃ for 1 hour, take it out and vacuum dry it at 60℃ for 30 minutes, apply solution B on its surface, and vacuum dry it at 50℃ for 30 minutes to obtain an outer lining; the coating thickness of solution B is 10μm;

[0033] S6: coating polyvinyl alcohol on both sides of the corrugated core paperboard, gluing the inner lining and the outer lining to the upper and lower sides of the corrugated core paperboard respectively, and drying to obtain moisture-proof and pressure-resistant packaging paper; preparing a moisture-proof and pressure-resistant packaging carton according to carton specifications.

[0034] Example 2: A method for preparing a moisture-proof and pressure-resistant packaging carton: S1: Crush the recycled cardboard box and add it to water, add 1% w / v sodium hydroxide solution, heat to 60°C and react at a consistency of 10wt% for 25 minutes, centrifuge to a consistency of 25wt%, and seal and store at 4°C to obtain pulp A; add 3wt% modified cellulose nanofibers, 0.5wt% cationic starch, and 0.8wt% colloidal silica to pulp A and stir for 30 minutes to obtain pulp B; add 7.5wt% sodium carboxymethyl cellulose and 0.9wt% calcium chloride to 1.5wt% pulp B and stir for 15 minutes to obtain pulp C; add 0.2wt% polyethyleneimine to pulp C, stir evenly, and form paper to obtain prototype paper, wherein the basis weight is 120g / m 2 ;

[0035] S2: The prototype paper was soaked in a 1 wt% carboxymethyl cellulose aqueous solution for 30 min, then soaked in a 0.2 mol / L copper sulfate solution for 3 h, and hot-pressed at 10 MPa and 120 °C for 6 h to obtain the lining;

[0036] S3: 2 wt% carboxymethyl cellulose was added to deionized water, heated to 60°C and stirred for 30 min, 2 wt% collagen fibers were added, cooled to 50°C and stirred for 1 h, and ultrasonicated for 20 min to obtain solution A;

[0037] S4: Add 2 wt% polyvinyl alcohol to deionized water, heat to 70°C and stir for 30 min, add sodium tetraborate decahydrate, and keep stirring for 30 min to obtain solution B; the amount of sodium tetraborate decahydrate added is 1.5 wt% of the mass of polyvinyl alcohol;

[0038] S5: Soak the prototype paper in a 1wt% carboxymethyl cellulose aqueous solution for 30 minutes, take it out and soak it in a 0.2mol / L aluminum chloride solution for 3 hours, 10MPa, and hot press at 120℃ for 6 hours to obtain an outer lining prototype paper; add 2g polyethyleneimine and 100mL methanol to 500mL deionized water, stir evenly, soak the outer lining prototype paper therein, heat to 35℃ and keep warm for 1 hour, take out the outer lining prototype paper and soak it in solution A, add 10mL glutaraldehyde, react at 25℃ for 1 hour, take it out and vacuum dry it at 60℃ for 30 minutes, apply solution B on its surface, and vacuum dry it at 50℃ for 30 minutes to obtain an outer lining; the coating thickness of solution B is 10μm;

[0039] S6: coating polyvinyl alcohol on both sides of the corrugated core paperboard, gluing the inner lining and the outer lining to the upper and lower sides of the corrugated core paperboard respectively, and drying to obtain moisture-proof and pressure-resistant packaging paper; preparing a moisture-proof and pressure-resistant packaging carton according to carton specifications.

[0040] Example 3: A method for preparing a moisture-proof and pressure-resistant packaging carton: S1: Crush the recycled cardboard box and add it to water, add 1% w / v sodium hydroxide solution, heat to 60°C and react at a consistency of 10wt% for 25 minutes, centrifuge to a consistency of 25wt%, and seal and store at 4°C to obtain pulp A; add 3wt% modified cellulose nanofibers, 0.5wt% cationic starch, and 0.8wt% colloidal silica to pulp A and stir for 30 minutes to obtain pulp B; add 7.5wt% sodium carboxymethyl cellulose and 0.9wt% calcium chloride to 1.5wt% pulp B and stir for 15 minutes to obtain pulp C; add 0.2wt% polyethyleneimine to pulp C, stir evenly, and form paper to obtain prototype paper, wherein the basis weight is 120g / m 2 ;

[0041] S2: The prototype paper was soaked in a 1 wt% carboxymethyl cellulose aqueous solution for 30 min, then soaked in a 0.2 mol / L copper sulfate solution for 3 h, and hot-pressed at 10 MPa and 120 °C for 6 h to obtain the lining;

[0042] S3: 2 wt% carboxymethyl cellulose was added to deionized water, heated to 60°C and stirred for 30 min, 10 wt% collagen fibers were added, cooled to 50°C and stirred for 1 h, and ultrasonicated for 20 min to obtain solution A;

[0043] S4: Add 2 wt% polyvinyl alcohol to deionized water, heat to 70°C and stir for 30 min, add sodium tetraborate decahydrate, and keep stirring for 30 min to obtain solution B; the amount of sodium tetraborate decahydrate added is 1.5 wt% of the mass of polyvinyl alcohol;

[0044] S5: Soak the prototype paper in a 1wt% carboxymethyl cellulose aqueous solution for 30 minutes, take it out and soak it in a 0.2mol / L aluminum chloride solution for 3 hours, 10MPa, and hot press at 120℃ for 6 hours to obtain an outer lining prototype paper; add 2g polyethyleneimine and 100mL methanol to 500mL deionized water, stir evenly, soak the outer lining prototype paper therein, heat to 35℃ and keep warm for 1 hour, take out the outer lining prototype paper and soak it in solution A, add 10mL glutaraldehyde, react at 25℃ for 1 hour, take it out and vacuum dry it at 60℃ for 30 minutes, apply solution B on its surface, and vacuum dry it at 50℃ for 30 minutes to obtain an outer lining; the coating thickness of solution B is 10μm;

[0045] S6: coating polyvinyl alcohol on both sides of the corrugated core paperboard, gluing the inner lining and the outer lining to the upper and lower sides of the corrugated core paperboard respectively, and drying to obtain moisture-proof and pressure-resistant packaging paper; preparing a moisture-proof and pressure-resistant packaging carton according to carton specifications.

[0046] Example 4: A method for preparing a moisture-proof and pressure-resistant packaging carton: S4: 10 wt% polyvinyl alcohol was added to deionized water, heated to 70°C and stirred for 30 minutes, sodium tetraborate decahydrate was added, and the mixture was kept warm and stirred for 30 minutes to obtain a solution B; the amount of sodium tetraborate decahydrate added was 1.5 wt% of the mass of the polyvinyl alcohol;

[0047] The remaining steps are the same as those in Example 3.

[0048] Comparative Example 1: A method for preparing a moisture-proof and pressure-resistant packaging carton: S5: soaking the prototype paper in a 1wt% carboxymethyl cellulose aqueous solution for 30 minutes, taking it out and soaking it in a 0.2mol / L copper sulfate solution for 3 hours, 10MPa, and hot pressing at 120°C for 6 hours to obtain an outer lining prototype paper; adding 2g of polyethyleneimine and 100mL of methanol to 500mL of deionized water, stirring evenly, soaking the outer lining prototype paper therein, heating to 35°C and keeping warm for 1 hour, taking out the outer lining prototype paper and soaking it in solution A, adding 10mL of glutaraldehyde, reacting at 25°C for 1 hour, taking it out and vacuum drying at 60°C for 30 minutes, coating solution B on its surface, and vacuum drying at 50°C for 30 minutes to obtain an outer lining; the coating thickness of solution B is 10μm;

[0049] The remaining steps are the same as those in Example 1.

[0050] Comparative Example 2: A method for preparing a moisture-proof and pressure-resistant packaging carton: S1: Crush the recycled cardboard box and add it to water, add 1% w / v sodium hydroxide solution, heat to 60°C and react at a consistency of 10wt% for 25 minutes, centrifuge to a consistency of 25wt%, and seal and store at 4°C to obtain pulp A; add 3wt% modified cellulose nanofibers, 0.5wt% cationic starch, and 0.8wt% colloidal silica to pulp A and stir for 30 minutes to obtain pulp B; add 0.2wt% polyethyleneimine to pulp B, stir evenly, and form paper to obtain prototype paper, wherein the basis weight is 120g / m 2 ;

[0051] The remaining steps are the same as those in Example 1.

[0052] Comparative Example 3: A method for preparing a moisture-proof and pressure-resistant packaging carton: S1: Crush the recycled cardboard box and add it to water, add 1% w / v sodium hydroxide solution, heat to 60°C and react at a consistency of 10wt% for 25 minutes, centrifuge to a consistency of 25wt%, and seal and store at 4°C to obtain pulp A; 2.5wt% sodium carboxymethyl cellulose and 0.9wt% calcium chloride are added to 1.5wt% pulp A and stirred for 15 minutes to obtain pulp B; 0.2wt% polyethyleneimine is added to pulp B, stirred evenly, and paper is formed to obtain prototype paper, wherein the basis weight is 120g / m 2 ;

[0053] The remaining steps are the same as those in Example 1.

[0054] Comparative Example 4: A method for preparing a moisture-proof and pressure-resistant packaging carton: S5: soaking the prototype paper in a 1 wt % carboxymethyl cellulose aqueous solution for 30 minutes, taking it out and soaking it in a 0.2 mol / L aluminum chloride solution for 3 hours, and hot pressing it at 10 MPa and 120°C for 6 hours to obtain an outer lining prototype paper; soaking the outer lining prototype paper in solution A for 10 minutes, taking it out and vacuum drying it at 60°C for 30 minutes, coating the surface of the outer lining with solution B, and vacuum drying it at 50°C for 30 minutes to obtain an outer lining; the coating thickness of solution B is 10 μm;

[0055] The remaining steps are the same as those in Example 1.

[0056] Experiment: Mechanical properties test: The moisture-proof and pressure-resistant packaging papers prepared in the above examples and comparative examples were tested using a paper testing machine with a load unit of 500N, a test speed of 1mm / min, and a test sample size of 1cm×3cm. The results are the average of five measurements.

[0057] Moisture-proof performance test: The moisture-proof and pressure-resistant packaging cartons prepared in the above examples and comparative examples were placed in an environment with 80% humidity and 25°C and stored for 24 hours. A paper testing machine was used with a load unit of 500N, a test speed of 1mm / min, and a test sample size of 1cm×3cm. The result was the average of five measurements.

[0058] The experimental data are shown in Table 1 below.

[0059] Table 1 Moisture-proof and pressure-resistant packaging carton performance test data

[0060]

[0061] Conclusion: The moisture-proof and pressure-resistant packaging paperboard prepared by the present invention has excellent moisture-proof performance and mechanical properties.

[0062] In comparative example 1, copper sulfate is used instead of aluminum chloride in the outer lining metal ion solution, resulting in reduced mechanical properties. In comparative example 2, sodium carboxymethyl cellulose and calcium chloride cross-linking structures are lacking, resulting in reduced mechanical properties. In comparative example 3, modified cellulose nanofibers are lacking, resulting in reduced mechanical properties. In comparative example 4, polyethyleneimine pretreatment and glutaraldehyde Schiff base cross-linking are lacking, resulting in reduced moisture resistance and mechanical properties.

[0063] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A moisture-proof and pressure-resistant packaging carton, characterized by: The moisture-proof and pressure-resistant packaging carton structure is sequentially provided with an outer lining, a corrugated core paperboard, and an inner lining from top to bottom, and the outer lining, the corrugated core paperboard, and the inner lining are bonded together by polyvinyl alcohol; The preparation method of the inner lining comprises the following steps: soaking the prototype paper in a 1-1.5wt% carboxymethyl cellulose aqueous solution for 30-45 minutes, taking it out and soaking it in a metal ion solution for 3-4 hours, and hot pressing it at 10-12MPa and 120-125°C for 6-6.5 hours to obtain the inner lining; The preparation method of the outer lining comprises the following steps: soaking a prototype paper in a 1-1.5wt% carboxymethyl cellulose aqueous solution for 30-45 minutes, taking it out and soaking it in a metal ion solution for 3-4 hours, hot pressing at 10-12MPa and 120-125°C for 6-6.5 hours to obtain the outer lining prototype paper; adding polyethyleneimine and methanol into deionized water, stirring evenly, soaking the outer lining prototype paper therein, heating it to 35-36°C and keeping it warm for 1-1.5 hours, taking out the outer lining prototype paper and soaking it in solution A, adding glutaraldehyde, reacting it under weak acid conditions at 25-30°C for 1-1.5 hours, taking it out and vacuum drying it at 60-65°C for 30-45 minutes, coating the surface of the outer lining with solution B, and vacuum drying it at 50-55°C for 30-45 minutes to obtain the outer lining; The preparation method of the solution A comprises the following steps: adding carboxymethyl cellulose to deionized water, heating to 60-62° C. and stirring for 30-35 minutes, adding collagen fibers, cooling to 50-52° C. and stirring for 1-1.5 hours, and ultrasonically treating for 20-30 minutes to obtain solution A; The preparation method of the solution B comprises the following steps: adding polyvinyl alcohol to deionized water, heating to 70-72° C. and stirring for 30-34 minutes, adding sodium tetraborate decahydrate, and stirring at the same temperature for 30-35 minutes to obtain solution B.

2. The moisture-proof and pressure-resistant packaging carton according to claim 1, characterized in that: During the preparation of the lining, the metal ion solution is a 0.2-0.3 mol / L copper sulfate solution; During the preparation of the outer lining prototype paper, the metal ion solution is a 0.2-0.3 mol / L aluminum chloride solution; during the preparation of the outer lining, the amount of polyethyleneimine added is 0.2-0.5 wt %, and the coating thickness of solution B is 8-20 μm.

3. The moisture-proof and pressure-resistant packaging carton according to claim 1, characterized in that: The method for preparing the prototype paper comprises the following steps: crushing recycled cardboard boxes and adding the crushed pieces to water, adding a 1% w / v sodium hydroxide solution, heating the crushed pieces to 60-62° C. and reacting them at a consistency of 10-12wt% for 20-30 minutes, centrifuging the crushed pieces to a consistency of 25-26wt%, and sealing and storing the crushed pieces at 4-5° C. to obtain pulp A; adding modified cellulose nanofibers, cationic starch, and colloidal silicon dioxide to the pulp A and stirring them for 30-45 minutes to obtain pulp B; adding sodium carboxymethyl cellulose and calcium chloride to 1.5-2wt% of the pulp B and stirring them for 15-20 minutes to obtain pulp C; and adding polyethyleneimine to the pulp C and stirring them evenly to form a paper sheet to obtain the prototype paper.

4. The moisture-proof and pressure-resistant packaging carton according to claim 3, characterized in that: During the preparation of pulp B, the amount of modified sodium cellulose added was 3-4wt%, the amount of cationic starch added was 0.5-0.6wt%, and the amount of colloidal silicon dioxide added was 0.8-1wt%. During the preparation of pulp C, the amount of sodium carboxymethyl cellulose added was 2.5-7.5wt%, and the amount of calcium chloride added was 0.9-1wt%. During the preparation of prototype paper, the amount of polyethyleneimine added was 0.1-0.3wt%, and the basis weight was 120-180g / m 2 .

5. The moisture-proof and pressure-resistant packaging carton according to claim 3, characterized in that: The method for preparing modified cellulose nanofibers comprises the following steps: dispersing bleached hardwood kraft pulp in water at a concentration of 1.5-2wt%, stirring and pulping for 30-45 minutes, filtering until the concentration of the bleached hardwood kraft pulp in water is 10-12wt%, stirring and expanding for 10-15 minutes, adding water until the concentration of the bleached hardwood kraft pulp in water is 5-5.5wt%, adding 0.1N hydrochloric acid solution to adjust the pH of the dispersion to 4.8-4.9, heating to 50-52°C, adding an enzyme mixture under stirring, keeping the temperature for hydrolysis reaction for 4-4.5 hours, heating to 80-82°C and keeping the temperature for 30-35 minutes, washing the enzyme-hydrolyzed pulp with ultrapure water, dispersing the washed pulp in water at a consistency of 1-1.2wt%, and homogenizing at 4-5°C to obtain modified cellulose nanofibers.

6. The moisture-proof and pressure-resistant packaging carton according to claim 1, characterized in that: During the preparation of solution A, the amount of carboxymethyl cellulose added is 2-3 wt %, and the amount of collagen fiber added is 2-10 wt %.

7. The moisture-proof and pressure-resistant packaging carton according to claim 1, characterized in that: During the preparation of solution B, the amount of polyvinyl alcohol added is 2-10 wt %, and the amount of sodium tetraborate decahydrate added is 1.5-2 wt % of the mass of polyvinyl alcohol.

8. The method for preparing a moisture-proof and pressure-resistant packaging carton according to any one of claims 1 to 7, characterized in that: The following steps are involved: Coating polyvinyl alcohol on both sides of the corrugated core paperboard, gluing the inner lining and the outer lining to the upper and lower sides of the corrugated core paperboard, and drying to obtain moisture-proof and pressure-resistant packaging paper; A moisture-proof and pressure-resistant packaging carton is prepared according to carton specifications.

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