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

Abstract

The invention discloses a moisture-proof and pressure-resistant packaging carton and a preparation method thereof, and relates to the technical field of packaging cartons, the structure of the moisture-proof and pressure-resistant packaging carton is sequentially provided with an outer lining, a corrugated core paperboard and an inner lining from top to bottom, and the outer lining, a corrugated core and the inner lining are bonded through polyvinyl alcohol; soaking the prototype paper in a carboxymethyl cellulose aqueous solution, taking out the prototype paper, soaking the prototype paper in a copper sulfate metal ion solution and an aluminum chloride metal ion solution respectively, and performing hot pressing to obtain lining prototype paper and outer lining prototype paper; the preparation method comprises the following steps: adding polyethyleneimine and methanol into deionized water, uniformly stirring, soaking the outer lining prototype paper into the deionized water, heating to 35-36 DEG C, preserving heat, taking out the outer lining prototype paper, soaking the outer lining prototype paper into the solution A, adding glutaraldehyde, reacting at 25-30 DEG C, taking out the outer lining prototype paper, carrying out vacuum drying for 30-45 minutes, coating the surface of the outer lining prototype paper with the solution B, and carrying out vacuum drying to obtain the outer lining.

Description

Technical Field

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

[0002] With the increasing awareness of environmental protection and the growing demand for sustainable development in the packaging industry, traditional carton materials are facing the challenge of insufficient performance under different environmental conditions, especially in humid environments. In particular, the compression resistance and moisture resistance of packaging materials are key factors affecting the quality and service life of cartons. Traditional paper packaging materials are usually prone to performance degradation in humid environments due to their strong hygroscopicity, resulting in reduced compressive strength of cartons, affecting the transportation and storage safety of goods.

[0003] Therefore, the development of innovative packaging materials with excellent mechanical properties and moisture-proof properties has become a technical problem that needs to be urgently solved 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: 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 by polyvinyl alcohol; 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.

[0006] 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 30-45min, taking it out and soaking it in a metal ion solution for 3-4h, 10-12MPa, 120-125℃ hot pressing for 6-6.5h to obtain the outer lining prototype paper; adding polyethyleneimine and methanol into deionized water, stirring evenly, soaking the outer lining prototype paper therein, heating to 35-36℃ and keeping warm for 1-1.5h, taking out the outer lining prototype paper and soaking it in solution A, adding glutaraldehyde, reacting under weak acid conditions at 25-30℃ for 1-1.5h, taking it out and vacuum drying it at 60-65℃ for 30-45min, coating the solution B on its surface, and vacuum drying it at 50-55℃ for 30-45min to obtain the outer lining.

[0007] 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 0.2-0.5wt%, and the coating thickness of solution B is 8-20μm.

[0008] Furthermore, the preparation method of the prototype paper includes the following steps: crushing the recycled cardboard box and adding it to water, adding 1% w / v sodium hydroxide solution, heating to 60-62°C and reacting at a consistency of 10-12wt% for 20-30min, 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 silicon dioxide to pulp A, stirring for 30-45min to obtain pulp B; adding sodium carboxymethyl cellulose and calcium chloride to 1.5-2wt% pulp B, stirring for 15-20min to obtain pulp C; adding polyethyleneimine to pulp C, stirring evenly, forming paper, and obtaining prototype paper.

[0009] Furthermore, in the preparation process of the 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%; in the preparation process 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%; in the preparation process of the prototype paper, the amount of polyethyleneimine added is 0.1-0.3wt%, and the basis weight is 120-180g / m 2 .

[0010] Furthermore, the preparation method of the modified cellulose nanofiber 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 4-4.5h, heating to 80-82°C and keeping the temperature for 30-35min, washing the enzyme hydrolyzed pulp with ultrapure water, dispersing the washed pulp in water at a consistency of 1-1.2wt%, homogenizing at 4-5°C, and obtaining modified cellulose nanofiber.

[0011] Furthermore, the enzyme mixture is added in an amount of 320 g / Tn.

[0012] Furthermore, the method for preparing solution A comprises the following steps: adding carboxymethyl cellulose to deionized water, heating to 60-62° C. and stirring for 30-35 min, adding collagen fibers, cooling to 50-52° C. and stirring for 1-1.5 h, and ultrasonically treating for 20-30 min to obtain solution A.

[0013] Furthermore, during the preparation of the solution A, the amount of carboxymethyl cellulose added is 2-3wt%, and the amount of collagen fiber added is 2-10wt%.

[0014] 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 the same temperature for 30-35 minutes to obtain solution B.

[0015] Furthermore, during the preparation of the solution B, the amount of polyvinyl alcohol added is 2-10wt%, and the amount of sodium tetraborate decahydrate added is 1.5-2wt% of the mass of the polyvinyl alcohol.

[0016] 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 respectively, sticking an inner liner and an outer liner to the upper and lower sides of the corrugated core paperboard respectively, and drying to obtain moisture-proof and pressure-resistant packaging paper; and preparing a moisture-proof and pressure-resistant packaging carton according to carton specifications.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 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 surface carboxyl groups of sodium carboxymethyl cellulose and the modified cellulose nanofibers and fibers. By adding calcium chloride, calcium chloride can be used as an ionic connector 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 can improve the bonding between nanostructured fibers and paperboard fibers. Due to the increase in the amount of bonding between fibers, the internal bonding of paper is significantly improved, greatly improving the mechanical properties of the carton.

[0018] 2. On the basis of the prototype paper, a carboxymethyl cellulose-metal ion cross-linked network is formed on its surface and internal components to further enhance the mechanical properties and waterproof properties of the prototype paper. CMC fills the gaps inside the OCC paper to form a denser structure. At the same time, the interpenetrating hydrogen bond network generated between the CMC molecular chain and the OCC fiber gives it excellent mechanical properties. The metal coordination strategy is used to improve the water resistance of OCC-CMC paper. After filling and hot pressing, the interlayer pores inside the OCC paper are eliminated, and a denser structure is obtained, which greatly improves the mechanical properties and moisture resistance of the carton.

[0019] 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 a humid environment, thereby increasing the service life and application scenarios of the carton. However, the cross-linked network it forms has low strength and is not suitable for use as an outer lining material.

[0020] 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

[0021] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the following examples, bleached hardwood kraft pulp was purchased from Stora Enso; corrugated core paperboard specifications: Nine Dragons corrugated paperboard 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; The preparation method of modified cellulose nanofibers comprises 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 4h, heating to 80°C and keeping the temperature for 30min, washing the enzyme hydrolyzed pulp with ultrapure water, dispersing the washed pulp in water at a consistency of 1wt%, homogenizing at 4°C, and obtaining modified cellulose nanofibers.

[0023] The enzyme mixture was added in an amount of 320 g / Tn.

[0024] 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 for 25 minutes at a consistency of 10wt%, 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 silicon dioxide 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 the paper to obtain prototype paper, wherein the basis weight is 120g / m 2 ; S2: The prototype paper was soaked in a 1wt% carboxymethyl cellulose aqueous solution for 30 min, taken out and soaked in a 0.2mol / L copper sulfate solution for 3 h, and hot pressed at 10MPa and 120°C for 6 h to obtain the lining; 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 ultrasonically treated for 20 min to obtain solution A; S4: Add 2 wt% polyvinyl alcohol into deionized water, heat to 70°C and stir for 30 min, add sodium tetraborate decahydrate, keep warm and stir for 30 min to obtain solution B; the amount of sodium tetraborate decahydrate added is 1.5 wt% of the mass of polyvinyl alcohol; 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, and hot press it at 10MPa and 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 it to 35℃ and keep it 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; S6: coating polyvinyl alcohol on both sides of the corrugated core paperboard, respectively 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.

[0025] Example 2: A method for preparing a moisture-proof and pressure-resistant packaging paper box: S1: Crush the recycled paper box and add it to water, add 1% w / v sodium hydroxide solution, heat to 60°C and react for 25 minutes at a consistency of 10wt%, 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 silicon dioxide 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 the paper to obtain prototype paper, wherein the basis weight is 120g / m 2 ; S2: The prototype paper was soaked in a 1wt% carboxymethyl cellulose aqueous solution for 30 min, taken out and soaked in a 0.2mol / L copper sulfate solution for 3 h, and hot pressed at 10MPa and 120°C for 6 h to obtain the lining; 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 ultrasonically treated for 20 min to obtain solution A; S4: Add 2 wt% polyvinyl alcohol into deionized water, heat to 70°C and stir for 30 min, add sodium tetraborate decahydrate, keep warm and stir for 30 min to obtain solution B; the amount of sodium tetraborate decahydrate added is 1.5 wt% of the mass of polyvinyl alcohol; 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, and hot press it at 10MPa and 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 it to 35℃ and keep it 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; S6: coating polyvinyl alcohol on both sides of the corrugated core paperboard, respectively 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.

[0026] 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 for 25 minutes at a consistency of 10wt%, 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 silicon dioxide 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 the paper to obtain prototype paper, wherein the basis weight is 120g / m 2 ; S2: The prototype paper was soaked in a 1wt% carboxymethyl cellulose aqueous solution for 30 min, taken out and soaked in a 0.2mol / L copper sulfate solution for 3 h, and hot pressed at 10MPa and 120°C for 6 h to obtain the lining; 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 ultrasonically treated for 20 min to obtain solution A; S4: Add 2 wt% polyvinyl alcohol into deionized water, heat to 70°C and stir for 30 min, add sodium tetraborate decahydrate, keep warm and stir for 30 min to obtain solution B; the amount of sodium tetraborate decahydrate added is 1.5 wt% of the mass of polyvinyl alcohol; 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, and hot press it at 10MPa and 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 it to 35℃ and keep it 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; S6: coating polyvinyl alcohol on both sides of the corrugated core paperboard, respectively 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.

[0027] Example 4: A method for preparing a moisture-proof and pressure-resistant packaging carton: S4: Add 10 wt% polyvinyl alcohol to deionized water, heat to 70°C and stir for 30 minutes, add sodium tetraborate decahydrate, keep warm and stir for 30 minutes to obtain solution B; the amount of sodium tetraborate decahydrate added is 1.5 wt% of the mass of polyvinyl alcohol; The remaining steps are the same as those in Example 3.

[0028] Comparative Example 1: A method for preparing a moisture-proof and pressure-resistant packaging paper box: 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 copper sulfate solution for 3 hours, 10MPa, and hot press at 120°C 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°C and keep warm for 1h, take out the outer lining prototype paper and soak it in solution A, add 10mL glutaraldehyde, react at 25°C for 1h, take it out and vacuum dry it at 60°C for 30min, apply solution B on its surface, and vacuum dry it at 50°C for 30min to obtain an outer lining; the coating thickness of solution B is 10μm; The remaining steps are the same as those in Example 1.

[0029] 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 for 25 minutes at a consistency of 10wt%, 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 the paper to obtain prototype paper, wherein the basis weight is 120g / m2 ; The remaining steps are the same as those in Example 1.

[0030] 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 for 25 minutes at a consistency of 10wt%, 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 ; The remaining steps are the same as those in Example 1.

[0031] Comparative Example 4: A method for preparing a moisture-proof and pressure-resistant packaging paper box: 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, hot press at 120℃ for 6 hours to obtain an outer lining prototype paper; soak the outer lining prototype paper in solution A for 10 minutes, 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; The remaining steps are the same as those in Example 1.

[0032] Experiment: Mechanical property test: The moisture-proof and compression-resistant packaging paper prepared in the above embodiments and comparative examples was 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 result is the average of five measurements.

[0033] Moisture-proof performance test: The moisture-proof and pressure-resistant packaging cartons prepared in the above embodiments and comparative examples were placed in an environment with 80% humidity and 25°C 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.

[0034] The experimental data are shown in Table 1 below.

[0035] Table 1 Moisture-proof and compression-resistant packaging carton performance test data table

[0036] Conclusion: The moisture-proof and pressure-resistant packaging paperboard prepared by the present invention has excellent moisture-proof performance and mechanical properties.

[0037] In Comparative Example 1, copper sulfate is used to replace 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.

[0038] 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 present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A moisture-proof and pressure-resistant packaging carton, characterized in that: The moisture-proof and pressure-resistant packaging carton structure is provided with an outer lining, a corrugated core paperboard, and an inner lining in sequence from top to bottom, and the outer lining, the corrugated core paperboard, and the inner lining are bonded 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 30-45min, taking it out and soaking it in a metal ion solution for 3-4h, hot pressing at 10-12MPa, 120-125°C for 6-6.5h to obtain the inner lining; The preparation method of the outer lining comprises the following steps: soaking the prototype paper in a 1-1.5wt% carboxymethyl cellulose aqueous solution for 30-45min, taking it out and soaking it in a metal ion solution for 3-4h, hot pressing at 10-12MPa, 120-125℃ for 6-6.5h to obtain the outer lining prototype paper; adding polyethyleneimine and methanol into deionized water, stirring evenly, soaking the outer lining prototype paper therein, heating to 35-36℃ and keeping warm for 1-1.5h, taking out the outer lining prototype paper and soaking it in solution A, adding glutaraldehyde, reacting under weak acid conditions at 25-30℃ for 1-1.5h, taking it out and vacuum drying at 60-65℃ for 30-45min, coating the solution B on its surface, and vacuum drying at 50-55℃ for 30-45min to obtain the outer lining.

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 preparation method of the prototype paper comprises the following steps: crushing a recycled cardboard box and adding it into water, adding a 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 silicon dioxide into pulp A, stirring for 30-45 minutes, to obtain pulp B; adding sodium carboxymethyl cellulose and calcium chloride into 1.5-2wt% pulp B, stirring for 15-20 minutes, to obtain pulp C; adding polyethyleneimine into pulp C, stirring evenly, forming paper, and obtaining the prototype paper.

4. The moisture-proof and pressure-resistant packaging carton according to claim 3, characterized in that: In the preparation process 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%; in the preparation process 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%; in the preparation process of prototype paper, the amount of polyethyleneimine added is 0.1-0.3wt%, and the basis weight is 120-180g / m 2 .

5. The moisture-proof and pressure-resistant packaging carton according to claim 3, characterized in that: The preparation method of the modified cellulose nanofiber comprises the following steps: dispersing bleached hardwood kraft pulp in water at a concentration of 1.5-2wt%, stirring and pulping for 30-45min, filtering until the concentration of the bleached hardwood kraft pulp in water is 10-12wt%, stirring and expanding for 10-15min, 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 4-4.5h, heating to 80-82°C and keeping the temperature for 30-35min, washing the enzyme hydrolyzed pulp with ultrapure water, dispersing the washed pulp in water at a consistency of 1-1.2wt%, homogenizing at 4-5°C, and obtaining the modified cellulose nanofiber.

6. The moisture-proof and pressure-resistant packaging carton according to claim 1, characterized in that: The method for preparing 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.

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

8. The moisture-proof and pressure-resistant packaging carton according to claim 1, characterized in that: The method for preparing 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 the solution B.

9. The moisture-proof and pressure-resistant packaging carton according to claim 8, characterized in that: During the preparation of solution B, the amount of polyvinyl alcohol added is 2-10wt%, and the amount of sodium tetraborate decahydrate added is 1.5-2wt% of the mass of polyvinyl alcohol.

10. A method for preparing a moisture-proof and pressure-resistant packaging carton according to any one of claims 1 to 9, characterized in that: The following steps are involved: Coating polyvinyl alcohol on both sides of the corrugated core paperboard, gluing the inner liner and the outer liner 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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