Corrugated board and preparation method thereof

Abstract

The invention discloses a corrugated board and a preparation method thereof, the corrugated board comprises surface paper, core paper and inner paper, the core paper is of a wave-shaped structure, and the surface paper and the inner paper are bonded with the core paper through an adhesive; the paper pulp formula of the surface paper, the core paper and the inner paper comprises the following raw materials: regenerated wood pulp, bamboo pulp, nano cellulose, modified starch and nano silicon dioxide. The corrugated board has the advantages of obdurability, high compression resistance and buffering performance and excellent waterproofness.

Description

Technical Field

[0001] The invention belongs to the technical field of packaging materials, and in particular relates to a corrugated cardboard and a preparation method thereof. Background Art

[0002] Corrugated cardboard is a widely used packaging material in logistics, transportation, and storage due to its lightweight, low cost, and excellent cushioning properties. However, traditional corrugated cardboard lacks strength, compressive strength, and water resistance, making it prone to deformation, breakage, and failure. Therefore, there is an urgent need to develop a corrugated cardboard that combines strength, high compressive strength, and excellent water resistance. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a corrugated paperboard and a preparation method thereof, wherein the corrugated paperboard has strong toughness, high compressive cushioning properties and excellent waterproofness.

[0004] The above technical objectives of the present invention are achieved through the following technical solutions:

[0005] A corrugated cardboard comprises face paper, core paper and lining paper, wherein the core paper is of a wavy structure and the face paper and lining paper are bonded to the core paper via an adhesive; the pulp formula of the face paper, core paper and lining paper comprises the following raw materials: recycled wood pulp, bamboo pulp, nanocellulose, modified starch and nanosilicon dioxide.

[0006] In some embodiments of the present invention, the pulp formula of the face paper, core paper and lining paper comprises the following raw materials in parts by weight: recycled wood pulp: 60-80 parts; bamboo pulp: 15-25 parts; nanocellulose: 5-15 parts; modified starch: 2-5 parts; nanosilica: 1-3 parts.

[0007] In some embodiments of the present invention, the diameter of the nanocellulose is 10-20 nm, and the aspect ratio of the nanocellulose is (5-50):1.

[0008] In some embodiments of the present invention, the modified starch is cationic starch, and the degree of substitution of the modified starch is 0.01-0.03.

[0009] In some embodiments of the present invention, the particle size of the nano-silica is 20-30 nm.

[0010] In some embodiments of the present invention, the corrugated height of the core paper is 4-5 mm, the wave pitch is 7-9 mm, and the basis weight is 100-150 g / m 2 .

[0011] In some embodiments of the present invention, the face paper and the inner paper are both planar structures, and the basis weight of the face paper and the inner paper is 150-180 g / m 2 .

[0012] In some embodiments of the present invention, the adhesive is a corn starch-based adhesive with a solid content of 25%-35%.

[0013] In some embodiments of the present invention, the corrugated board has a tensile strength of 5.5-6.5 kN / m, an edge compression strength of 1100-1400 N / m, and a contact angle of 130-145°.

[0014] A method for preparing the corrugated paperboard as described above comprises the following steps:

[0015] (1) Pulp preparation: recycled wood pulp, bamboo pulp and nanocellulose are mixed and beaten, and then modified starch and nano-silicon dioxide are added and mixed to obtain mixed pulp;

[0016] (2) Nanomaterial dispersion: The mixed pulp is subjected to ultrasonic dispersion treatment;

[0017] (3) Core paper forming: the mixed pulp is fed into the corrugated forming machine to prepare corrugated core paper;

[0018] (4) Preparation of face paper and lining paper: The face paper and lining paper are prepared by papermaking process using mixed pulp of the same formulation;

[0019] (5) Composite bonding: Use adhesive to bond the face paper, core paper and lining paper, and heat press to form;

[0020] (6) Post-processing: Dry the laminated corrugated cardboard and cut it into shape.

[0021] In some embodiments of the present invention, in step (1), the beating degree after beating is 35-45°SR.

[0022] In some embodiments of the present invention, in step (2), the power of the ultrasonic dispersion is 400-600 W, and the time of the ultrasonic dispersion is 5-15 minutes.

[0023] In some embodiments of the present invention, in step (5), the hot pressing is performed at a temperature of 100-140° C., a pressure of 0.4-0.6 MPa, and a time of 20-40 seconds.

[0024] In some embodiments of the present invention, in step (6), the drying temperature is 50-80° C. and the drying time is 1-3 hours.

[0025] The beneficial effects of the present invention are as follows: the corrugated paperboard of the present invention introduces specific nanocellulose, modified starch and nanosilica into the pulp formula, wherein the nanocellulose forms a network structure in the pulp, the nanosilica is interspersed in the network structure, and is combined with the modified starch to give the paperboard good strength and waterproof properties. At the same time, the preparation process is simple and easy to industrialize. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to specific embodiments.

[0027] Example 1:

[0028] A corrugated cardboard, whose pulp formula comprises the following raw materials in parts by weight: 60 parts of recycled wood pulp; 15 parts of bamboo pulp; 5 parts of nanocellulose; 2 parts of modified starch; and 3 parts of nanosilicon dioxide. The nanocellulose has a diameter of 10-20 nm and an aspect ratio of (5-50):1. The modified starch is cationic starch with a degree of substitution of 0.01. The nanosilicon dioxide has a particle size of 20-30 nm.

[0029] The method for preparing the corrugated board as described above comprises the following steps:

[0030] (1) Pulp preparation: Recycled wood pulp, bamboo pulp and nanocellulose are mixed, and water is added to beat the pulp until the pulp density is 35°SR, and then modified starch and nano-silica are added and mixed and stirred to obtain mixed pulp;

[0031] (2) Nanomaterial dispersion: The mixed pulp was placed in an ultrasonic dispersion device at 400 W for 15 minutes to ensure that the nanocellulose and nanosilica were evenly dispersed;

[0032] (3) Core paper forming: The mixed pulp is fed into the corrugated forming machine to prepare a corrugated core paper with a corrugated height of 4 mm and a corrugated pitch of 7 mm, with a basis weight of 100 g / m 2 Core paper;

[0033] (4) Preparation of face paper and back paper: Mixed pulp with the same formula is used to prepare paper with a basis weight of 150g / m 2 The face paper and the inner paper are both flat structures;

[0034] (5) Composite bonding: Use a corn starch-based adhesive with a solid content of 25% to bond the face paper, core paper, and lining paper, and hot press them at a temperature of 100°C, a pressure of 0.6 MPa, and a time of 20 seconds;

[0035] (6) Post-processing: Dry the composite corrugated cardboard at 50°C for 3 hours and cut into the required size.

[0036] Example 2:

[0037] A corrugated cardboard, whose pulp formula comprises the following raw materials in parts by weight: 80 parts of recycled wood pulp; 25 parts of bamboo pulp; 15 parts of nanocellulose; 5 parts of modified starch; and 1 part of nanosilicon dioxide. The nanocellulose has a diameter of 10-20 nm and an aspect ratio of (5-50):1. The modified starch is cationic starch with a degree of substitution of 0.03. The nanosilicon dioxide has a particle size of 20-30 nm.

[0038] The method for preparing the corrugated board as described above comprises the following steps:

[0039] (1) Pulp preparation: Recycled wood pulp, bamboo pulp and nanocellulose are mixed, and water is added to beat the pulp until the pulp density is 45°SR, and then modified starch and nano-silica are added and mixed and stirred to obtain mixed pulp;

[0040] (2) Nanomaterial dispersion: The mixed pulp was placed in an ultrasonic dispersion device at 600 W for 5 minutes to ensure that the nanocellulose and nanosilica were evenly dispersed;

[0041] (3) Core paper forming: The mixed pulp is fed into the corrugated forming machine to prepare a corrugated core paper with a corrugated height of 5 mm and a corrugated pitch of 9 mm, with a basis weight of 150 g / m 2 Core paper;

[0042] (4) Preparation of face paper and back paper: Mixed pulp with the same formula is used to prepare paper with a basis weight of 180g / m 2 The face paper and the inner paper are both flat structures;

[0043] (5) Composite bonding: Use a corn starch-based adhesive with a solid content of 35% to bond the face paper, core paper, and lining paper, and hot press them at a temperature of 140°C, a pressure of 0.4 MPa, and a time of 40 seconds;

[0044] (6) Post-processing: Dry the laminated corrugated cardboard at 80°C for 1 hour and cut into the required size.

[0045] Example 3:

[0046] A corrugated cardboard, whose pulp formula comprises the following raw materials in parts by weight: 70 parts of recycled wood pulp; 20 parts of bamboo pulp; 10 parts of nanocellulose; 3 parts of modified starch; and 2 parts of nanosilicon dioxide. The nanocellulose has a diameter of 10-20 nm and an aspect ratio of (5-50):1. The modified starch is cationic starch with a degree of substitution of 0.02. The nanosilicon dioxide has a particle size of 20-30 nm.

[0047] The method for preparing the corrugated board as described above comprises the following steps:

[0048] (1) Pulp preparation: Recycled wood pulp, bamboo pulp and nanocellulose are mixed, and water is added to beat the pulp until the pulp density is 40°SR, and then modified starch and nano-silica are added and mixed and stirred to obtain mixed pulp;

[0049] (2) Nanomaterial dispersion: The mixed pulp was placed in an ultrasonic dispersion device at 500 W for 10 min to ensure that the nanocellulose and nanosilica were evenly dispersed;

[0050] (3) Core paper forming: The mixed pulp is fed into the corrugated forming machine to prepare a corrugated core paper with a corrugated height of 4.5 mm and a wave pitch of 8 mm, with a basis weight of 120 g / m 2 Core paper;

[0051] (4) Preparation of face paper and back paper: Mixed pulp with the same formula is used to prepare paper with a basis weight of 150g / m 2 The face paper and the inner paper are both flat structures;

[0052] (5) Composite bonding: Use a corn starch-based adhesive with a solid content of 30% to bond the face paper, core paper, and lining paper, and hot press them at a temperature of 120°C, a pressure of 0.5 MPa, and a time of 30 seconds;

[0053] (6) Post-processing: Dry the composite corrugated cardboard at 60°C for 2 hours and cut it into the required size.

[0054] Comparative Example 1:

[0055] A corrugated paperboard, wherein the pulp formula thereof differs from that of Example 3 only in that it does not contain nanocellulose, and the rest of the formula and preparation method are exactly the same as those of Example 3.

[0056] Comparative Example 2:

[0057] A corrugated paperboard, wherein the pulp formula thereof differs from that of Example 3 only in that the modified starch is not contained, and the rest of the formula and preparation method are exactly the same as those of Example 3.

[0058] Comparative Example 3:

[0059] A corrugated paperboard, wherein the pulp formula thereof differs from that of Example 3 only in that it does not contain nano-silicon dioxide, and the rest of the formula and preparation method are exactly the same as those of Example 3.

[0060] Comparative Example 4:

[0061] The conventional corrugated cardboard on the market is composed of face paper, core paper and lining paper. The basis weights of the face paper, core paper and lining paper are the same as those in Example 3. The corrugation height and wave pitch of the core paper are the same as those in Example 3.

[0062] Test example:

[0063] The relevant properties of the corrugated boards of Examples 1-3 and Comparative Examples 1-4 were tested respectively. The test results are shown in Table 1.

[0064] Table 1. Performance test results

[0065]

[0066] As shown in Table 1, the tensile strength of the corrugated board of the present invention can reach over 5.5 kN / m, the edge compression strength can reach over 1100 N / m, and the contact angle is greater than 130°, indicating that the corrugated board of the present invention combines toughness, high compressive cushioning, and excellent water resistance. A comparison of Example 3 with Comparative Examples 1-3 also shows that when the pulp formulation of the corrugated board lacks one of nanocellulose, modified starch, and nanosilica, the relevant properties are degraded.

[0067] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A corrugated cardboard, characterized in that: The invention comprises face paper, core paper and lining paper, wherein the core paper is a wavy structure, and the face paper and lining paper are bonded to the core paper by an adhesive; the pulp formula of the face paper, core paper and lining paper comprises the following raw materials: recycled wood pulp, bamboo pulp, nanocellulose, modified starch and nanosilica.

2. The corrugated paperboard according to claim 1, characterized in that: The pulp formula of the face paper, core paper and lining paper comprises the following raw materials in parts by weight: recycled wood pulp: 60-80 parts; bamboo pulp: 15-25 parts; nano cellulose: 5-15 parts; modified starch: 2-5 parts; and nano silicon dioxide: 1-3 parts.

3. The corrugated paperboard according to claim 1, characterized in that: The diameter of the nanocellulose is 10-20 nm, and the aspect ratio of the nanocellulose is (5-50):

1.

4. The corrugated paperboard according to claim 1, characterized in that: The modified starch is cationic starch, and the degree of substitution of the modified starch is 0.01-0.

03.

5. The corrugated paperboard according to claim 1, characterized in that: The particle size of the nano-silicon dioxide is 20-30 nm.

6. The corrugated paperboard according to claim 1, characterized in that: The core paper has a corrugated height of 4-5 mm, a wave pitch of 7-9 mm, and a basis weight of 100-150 g / m 2 .

7. The corrugated paperboard according to claim 1, characterized in that: The adhesive is a corn starch-based adhesive with a solid content of 25%-35%.

8. A method for preparing a corrugated board according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Pulp preparation: recycled wood pulp, bamboo pulp and nanocellulose are mixed and beaten, and then modified starch and nano-silicon dioxide are added and mixed to obtain mixed pulp; (2) Nanomaterial dispersion: The mixed pulp is subjected to ultrasonic dispersion treatment; (3) Core paper forming: the mixed pulp is fed into the corrugated forming machine to prepare corrugated core paper; (4) Preparation of face paper and lining paper: The face paper and lining paper are prepared by papermaking process using mixed pulp of the same formulation; (5) Composite bonding: Use adhesive to bond the face paper, core paper and lining paper, and heat press to form; (6) Post-processing: Dry the laminated corrugated cardboard and cut it into shape.

9. The method for preparing corrugated paperboard according to claim 8, wherein: In step (1), the beating degree after beating is 35-45°SR.

10. The method for preparing corrugated paperboard according to claim 8, wherein: In step (2), the power of the ultrasonic dispersion is 400-600W, and the time of the ultrasonic dispersion is 5-15 minutes.

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