Bamboo fiber barrier packaging paper and its preparation method and application

Abstract

The present invention discloses a bamboo fiber barrier wrapping paper, and its preparation method and application. The preparation method of the bamboo fiber barrier wrapping paper comprises the following steps: bleached sulfate bamboo fiber and bamboo shoot shell fiber are pulped and dispersed respectively, and then mixed to form a BF / SF mixed slurry; then bamboo powder is added to obtain a BF / SF / BP compound slurry; then the slurry is sheet-formed and shaped, and the surface of the obtained paper is sprayed with a surface sizing agent (diquaternary ammonium salt chitosan and bamboo nanocellulose), and finally the bamboo fiber barrier wrapping paper is obtained by hot rolling. The present invention rationally utilizes bamboo fiber raw materials of different forms, enhances the mechanical strength, toughness, barrier properties and antibacterial properties of the wrapping paper, and can be used in the field of mildew-proof packaging materials for grains.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging materials, and in particular to a bamboo fiber barrier packaging paper and a preparation method and application thereof. Background Art

[0002] Bamboo boasts wide distribution, rapid growth, high yield, and is renewable and biodegradable. It not only possesses excellent ecological value, such as water conservation, soil and water conservation, climate regulation, and air purification, but also possesses high economic and unique cultural value, making it a globally significant non-wood forest resource. As a sustainable ecological material, bamboo has become a highly sought-after modern green engineering material due to its abundant yield, lightweight, high strength, and excellent carbon sequestration properties. Currently, initiatives are underway across the country to tap into bamboo resources, develop the bamboo industry, expand the bamboo economy, cultivate bamboo culture, and share bamboo life. These initiatives aim to create a complete "bamboo chain," leveraging bamboo to bridge both ecological and economic dimensions and build a platform for the high-quality development of the bamboo industry. Therefore, bamboo plays a vital role in promoting ecological civilization.

[0003] With increasingly stringent plastic restrictions and bans, the application areas of petroleum-based plastic products are limited, and the search for plastic alternatives is urgent. Countries are shouldering their social responsibility for green development. Bamboo products can replace plastic products in many areas, truly replacing plastic with bamboo, including daily necessities, packaging, building materials, and automotive materials. The packaging materials industry is currently moving towards green and low-carbon development, and bamboo or bamboo fiber can be used as a 100% green packaging material in the packaging field. "Bamboo instead of plastic" products can be widely used in daily necessities such as bamboo straws, bamboo tableware, bamboo baskets, and bamboo woven packaging. With the rapid development of logistics, the variety of bamboo packaging will continue to increase. Therefore, the preparation of a bamboo fiber barrier packaging paper is of great practical significance and will contribute to the "bamboo instead of plastic" campaign. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a method for preparing bamboo fiber barrier packaging paper.

[0005] Another object of the present invention is to provide bamboo fiber barrier packaging paper prepared by the preparation method.

[0006] Another object of the present invention is to provide an application of the bamboo fiber barrier packaging paper.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A method for preparing bamboo fiber barrier packaging paper comprises the following steps:

[0009] (1) Bamboo fiber compound:

[0010] Bleached sulfate bamboo fiber (BF) and bamboo shoot fiber (SF) are beaten to obtain BF pulp with a beating degree of 40-55°SR and SF pulp with a beating degree of 50-60°SR; the BF pulp and SF pulp are then fully dispersed to obtain BF dispersion and SF dispersion; the BF dispersion and SF dispersion are then mixed to obtain a BF / SF mixed pulp;

[0011] (2) Adding filler: adding bamboo powder (BP) to the BF / SF mixed slurry obtained in step (1) under stirring conditions, mixing evenly to obtain a BF / SF / BP composite slurry;

[0012] (3) Papermaking: The BF / SF / BP composite slurry obtained in step (2) is subjected to papermaking, forming, dehydration, and drying to obtain paper sample I;

[0013] (4) Surface spraying: The outer surface of the paper sample I obtained in step (3) is sprayed with a surface sizing agent, and then dried to obtain a paper sample II; wherein the surface sizing agent is a composite solution of diquaternary ammonium salt chitosan and bamboo nanocellulose;

[0014] (5) Hot rolling treatment: The paper sample II obtained in step (4) is subjected to hot rolling treatment and then dried to obtain a bamboo fiber barrier packaging paper.

[0015] The beating treatment described in step (1) is performed using a PFI mill.

[0016] The bleached sulfate bamboo fiber described in step (1) has a length of 2 to 15 mm and a diameter of 27 to 52 μm; the bamboo shoot shell fiber has a length of 5 to 20 mm and a diameter of 30 to 45 μm.

[0017] The beating treatment conditions of the bleached sulfate bamboo fiber described in step (1) are: the beating rotation number is 3000-6000 revolutions, and the beating concentration is 1.0-2.0wt%; the beating treatment conditions of the bamboo shoot shell fiber are: the beating rotation number is 6000-9000 revolutions, and the beating concentration is 1.5-2.5wt%.

[0018] The dispersion treatment of the BF slurry in step (1) is achieved by the following method: the BF slurry is dispersed at a concentration of 1.0 to 2.5% by mass at a rotation speed of 3000 to 6000 r / min for 10 to 25 minutes.

[0019] The dispersion treatment of the SF slurry in step (1) is achieved by dispersing the SF slurry at a concentration of 1.5 to 3.0% by mass at a rotation speed of 4000 to 7000 r / min for 15 to 30 minutes.

[0020] The mass ratio (absolute dry) of the bleached sulfate bamboo fiber (BF) and the bamboo shoot shell fiber (SF) described in step (1) is (5:5) to (8:2).

[0021] The stirring speed in step (2) is 3000-6000 r / min.

[0022] The bamboo powder described in step (2) is a nano-scale antibacterial bamboo powder having a particle diameter of 50 to 500 nm; preferably, the nano-scale antibacterial bamboo powder is prepared by mechanically crushing bamboo slices and adding an antibacterial agent; more preferably, the powder is prepared by the following method:

[0023] Bamboo slices of Phyllostachys pubescens are mechanically crushed at room temperature and 3000-5000 rpm to obtain bamboo powder; the bamboo powder is then immersed in an antibacterial solution containing quaternary ammonium chitosan and dried to obtain nano-level antibacterial bamboo powder.

[0024] The mechanical crushing is performed 2 to 5 times.

[0025] The antibacterial liquid containing quaternary ammonium chitosan is prepared by the following method: quaternary ammonium chitosan and polyethylene glycol are dissolved in water respectively, and then mixed together, and the solid content of the quaternary ammonium chitosan is controlled to be 5% to obtain the antibacterial liquid containing quaternary ammonium chitosan.

[0026] The mass ratio of the quaternary ammonium chitosan to the polyethylene glycol is (1-5): (6-10).

[0027] The immersion time is 30 to 180 minutes.

[0028] The amount of bamboo powder added in step (2) is 1.0-5.0% of the mass (absolute dry) of the BF / SF / BP composite slurry.

[0029] The papermaking and forming described in step (3) is carried out by using a rotary paper machine.

[0030] The slurry concentration of the BF / SF / BP compound slurry described in step (3) is 1.2-1.8% by mass.

[0031] The mass ratio (absolute dry) of diquaternary ammonium salt chitosan and bamboo nanocellulose in the surface sizing agent described in step (4) is (5:5) to (7:3).

[0032] The concentration of the surface sizing agent in step (4) is 1.5-3.0% by mass.

[0033] The surface sizing agent described in step (4) is sprayed on the outer surface in an amount of 1.5 to 4.0 g / m 2 .

[0034] The drying method described in step (4) is: infrared drying at 100-200° C. for 50-80 minutes.

[0035] The hot rolling conditions described in step (5) are: temperature of 90-100° C., pressure of 20-25 MPa, and time of 20-40 min.

[0036] The drying method described in step (5) is: infrared drying at 60-80° C. for 10-30 minutes.

[0037] A bamboo fiber barrier packaging paper is prepared by any of the methods described above.

[0038] The performance indicators of the bamboo fiber barrier packaging paper are as follows: Basis weight: 45-50g / m 2 Tensile strength: 2.72-3.16 kN / m; Tear strength: 621.5-725.3 mN; Oxygen permeability: 464-551 cm 3 / m 2 ·day·0.1MPa; Water vapor transmission rate: 132~178g / m 2 ·day; antibacterial rate: 88-95%.

[0039] Application of the bamboo fiber barrier packaging paper in packaging materials.

[0040] The packaging material includes a mildew-proof packaging material; preferably, the mildew-proof packaging material is used for packaging grain.

[0041] The food includes rice, wheat, beans and coarse grains.

[0042] The present invention has the following advantages and effects compared to the prior art:

[0043] (1) The present invention uses nanmu bamboo as raw material. Bamboo has the advantages of fast growth, wide source, green environmental protection, and renewability. The barrier packaging paper prepared from different forms of raw materials such as bamboo fiber, bamboo shoot fiber, bamboo powder, and bamboo nanocellulose from the same bamboo can be naturally degraded or recycled. It is a green packaging material and can be used in the field of mildew-proof packaging materials for grain by replacing plastic with paper.

[0044] (2) The bamboo fiber barrier wrapping paper prepared by the present invention is prepared by rationally compounding two fiber raw materials from bamboo, making full use of the advantages of different bamboo fibers: bamboo fibers are long and strong, which can significantly improve the physical strength of bamboo paper; bamboo shoot shell fibers are delicate and soft, with good fiber morphology, which can ensure close bonding between fibers; in addition, bamboo shoot shell fibers contain flavonoids, wax and other substances, which have mildew-proof and antibacterial effects, and are beneficial to improving the antibacterial effect of wrapping paper; the impregnated nano bamboo powder can not only be used as a filler reinforcement, but also has a good antibacterial and moisture-proof effect.

[0045] (3) The present invention uses diquaternary ammonium salt chitosan, which has excellent antibacterial properties and can impart antibacterial properties to wrapping paper. The chitosan surface contains amino groups, which are positively charged and can form strong covalent bonds and hydrogen bonds with the hydroxyl groups on the cellulose surface, increasing the cross-linking between the fiber and the chitosan. On the one hand, it can increase the mechanical strength of the wrapping paper, and on the other hand, it can improve the pore structure of the wrapping paper and increase the antibacterial and oxygen barrier capabilities. The addition of bamboo nanocellulose is conducive to improving the interface between the sizing agent and the paper base surface. The spraying process helps to make the wrapping paper surface smoother, so that the coated wrapping paper exhibits good mechanical strength, toughness and barrier properties.

[0046] (4) The present invention adopts infrared drying treatment technology, which is beneficial to improving the uniformity and smoothness of the paper surface. At the same time, the hot rolling treatment is beneficial to softening and interweaving the bamboo fibers, improving the uniformity and strength of the wrapping paper, and making the various fibers inside the paper substrate more tightly combined, so that the wrapping paper has stronger toughness and density.

[0047] (5) The bamboo fiber, bamboo shoot fiber, bamboo powder and bamboo nanocellulose used in the present invention are all derived from Phyllostachys nanmu, realizing the utilization of all components of a bamboo. The prepared bamboo fiber barrier packaging paper has good mechanical properties, barrier properties and antibacterial properties, and can be used in the field of mildew-proof packaging materials for grains. It will promote the green packaging industry to achieve low-carbon development and truly realize the use of bamboo instead of plastic. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the preparation process of the bamboo fiber barrier packaging paper of the present invention.

[0049] Figure 2 3 is a scanning electron microscope image of the cross section of the bamboo fiber barrier packaging paper obtained in Example 1. DETAILED DESCRIPTION

[0050] The present invention will be described in further detail below in conjunction with the examples, but embodiments of the present invention are not limited thereto. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art. The test methods in the following examples where specific experimental conditions are not specified are generally based on conventional experimental conditions. Unless otherwise specified, the reagents and raw materials used in the present invention can be obtained commercially.

[0051] 1. The bleached sulfate bamboo fiber (BF) used in the Examples and Comparative Examples was obtained from pulp produced at the State Key Laboratory of Papermaking Engineering, with a length of 2 to 15 mm and a diameter of 27 to 52 μm. The bamboo shoot husk fiber (SF) was obtained from pulp produced at the State Key Laboratory of Papermaking Engineering, with a length of 5 to 20 mm and a diameter of 30 to 45 μm. Diquaternary ammonium chitosan was purchased from Sigma-Aldrich, with a degree of substitution of 95.8%.

[0052] 2. The nano-antibacterial bamboo powder (Phyllostachys pubescens bamboo powder, BP) involved in the embodiments of the present invention and the comparative examples is prepared by mechanical crushing of Phyllostachys pubescens bamboo chips; wherein the mechanical crushing conditions are: crushing 2 to 5 times at a rotation speed of 3000 to 5000 rpm under room temperature; then the bamboo powder is immersed in an antibacterial liquid (quaternary ammonium chitosan (purchased from Shandong Fengtai Chemical Technology Co., Ltd., with a degree of substitution of 95% and a fineness of 40 mesh sieving rate of 95%) and polyethylene glycol are dissolved in deionized water, and then mixed, and the mass ratio of quaternary ammonium chitosan to polyethylene glycol is (1 to 5): (6 to 10), and the solid content of quaternary ammonium chitosan is 5%) for 30 to 180 min, and dried to obtain nano-antibacterial bamboo powder (BP) (particle diameter of 50 to 500 nm).

[0053] 3. The bamboo nanocellulose involved in the embodiments of the present invention and the comparative examples is made of bamboo pulp as raw material, and is prepared by mechanical grinding and high-pressure homogenization, with a diameter of 26 to 83 nm and a length of 160 to 740 nm; wherein the conditions for mechanical grinding are: grinding 6 times at 0 and -50 μm gaps, and a speed of 1000 rpm; grinding 12 times at a gap of -100 μm, and a speed of 1500 rpm; then grinding 20 times at a gap of -150 μm, and a speed of 2000 rpm; the conditions for high-pressure homogenization are: operating pressure 180 MPa, 6 cycles, and temperature control at 25°C.

[0054] 4. The various parameters involved in the embodiments of the present invention are tested in accordance with national standard testing methods and industry standards, specifically:

[0055] ①Quantitative determination (GB / T 451.2-2002);

[0056] ②Tensile strength (GB / T 453-2002);

[0057] ③ Tear strength (GB / T 455-2002);

[0058] ④Oxygen permeability (GB / T 19789-2005);

[0059] ⑤ Water vapor transmission rate (GB / T 22921-2008);

[0060] ⑥ Inhibition rate (GB15979-2002), the colonies selected were Staphylococcus aureus (BNCC188012) and Escherichia coli (BNCC364150), both purchased from Beina Chuanglian Biotechnology Co., Ltd.

[0061] The schematic diagram of the preparation process of the bamboo fiber barrier packaging paper of the present invention is as follows: Figure 1 shown.

[0062] Example 1

[0063] This embodiment provides a method for preparing bamboo fiber barrier packaging paper, and the specific preparation steps are as follows:

[0064] (1) Bamboo fiber compounding: Bleached sulfate bamboo fiber (BF, length 2-15 mm, diameter 27-52 μm) was beaten in a PFI mill at 3000 rpm, a beating concentration of 1.0 wt%, and a beating degree of 40°SR; bamboo shoot husk fiber (SF, length 5-20 mm, diameter 30-45 μm) was beaten in a PFI mill at 6000 rpm, a beating concentration of 1.5 wt%, and a beating degree of 50°SR. The beaten bleached sulfate bamboo fiber was then dispersed in an electric disperser at a speed of 3000 r / min for 10 min at a concentration of 1.0% by mass, and the beaten bamboo shoot husk fiber was dispersed in an electric disperser at a speed of 4000 r / min for 15 min at a concentration of 1.5% by mass. Finally, the bleached sulfate bamboo fiber dispersion and the bamboo shoot shell fiber dispersion obtained after the dispersion treatment are uniformly mixed at an absolute dry mass ratio of 8:2 (i.e., the mass ratio of the bleached sulfate bamboo fiber to the bamboo shoot shell fiber, the same below) to obtain a BF / SF mixed slurry solution.

[0065] (2) Filler addition: nano-antibacterial bamboo powder (BP) (particle diameter of 50 to 500 nm) was added to the BF / SF mixed slurry solution in step (1) under high-speed stirring (rotation speed: 3000 r / min), wherein the amount of nano-antibacterial bamboo powder added was 1.0% of the absolute dry mass of the BF / SF / BP composite slurry, and the mixture was mixed uniformly to obtain a BF / SF / BP composite slurry.

[0066] (3) Papermaking process: The BF / SF / BP composite slurry obtained in step (2) is paper-formed on a rotary paper machine at a slurry concentration of 1.2 wt%, dehydrated, and dried to obtain paper sample A.

[0067] (4) Surface spraying: Spray the front and back surfaces of the paper sample obtained in step (3) with a 1.5% mass concentration of a composite liquid of diquaternary ammonium salt chitosan and bamboo nanocellulose, wherein the absolute dry mass ratio of diquaternary ammonium salt chitosan and bamboo nanocellulose is 5:5, and the outer surface spraying amount is 1.5 g / m 2 , and then use an electric infrared generator to infrared dry the paper sample at 100°C for 50 minutes to obtain paper sample B.

[0068] (5) Hot rolling treatment: The paper sample B obtained in step (4) was hot rolled at a temperature of 90° C. and a pressure of 20 MPa for 20 min, and then infrared dried at 60° C. for 10 min to obtain a bamboo fiber barrier packaging paper.

[0069] The cross-sectional scanning electron microscope image of the bamboo fiber barrier packaging paper prepared in this embodiment is as follows: Figure 1 As shown, the performance indicators of the bamboo fiber barrier packaging paper are as follows: Basis weight: 45g / m 2 Tensile strength: 2.72kN / m; Tear strength: 621.5mN; Oxygen permeability: 551cm 3 / m 2 ·day·0.1MPa; Water vapor transmission rate: 178g / m 2 ·day; antibacterial rate: 88%.

[0070] Example 2

[0071] This embodiment provides a method for preparing bamboo fiber barrier packaging paper, and the specific preparation steps are as follows:

[0072] (1) Bamboo fiber compounding: Bleached sulfate bamboo fiber (BF, length 2-15 mm, diameter 27-52 μm) was beaten in a PFI mill at a beating speed of 4000 rpm, a beating concentration of 1.5 wt%, and a beating degree of 45°SR; bamboo shoot husk fiber (SF, length 5-20 mm, diameter 30-45 μm) was beaten in a PFI mill at a beating speed of 7000 rpm, a beating concentration of 2.0 wt%, and a beating degree of 55°SR. The beaten bleached sulfate bamboo fiber was then dispersed in an electric disperser at a speed of 4000 r / min for 15 min at a concentration of 1.5% by mass, and the beaten bamboo shoot husk fiber was dispersed in an electric disperser at a speed of 5000 r / min for 20 min at a concentration of 2.0% by mass. Finally, the bleached sulfate bamboo fiber dispersion obtained after the dispersion treatment and the bamboo shoot shell fiber dispersion were uniformly mixed at an absolute dry mass ratio of 7:3 to obtain a BF / SF mixed slurry solution.

[0073] (2) Filler addition: nano-antibacterial bamboo powder (BP) (particle diameter of 50 to 500 nm) was added to the BF / SF mixed slurry solution in step (1) under high-speed stirring (rotation speed: 4000 r / min), wherein the amount of nano-antibacterial bamboo powder added was 2.0% of the absolute dry mass of the BF / SF / BP composite slurry, and the mixture was mixed uniformly to obtain a BF / SF / BP composite slurry.

[0074] (3) Papermaking process: The BF / SF / BP composite slurry obtained in step (2) is paper-formed on a rotary paper machine at a slurry concentration of 1.4 wt%, dehydrated, and dried to obtain paper sample A.

[0075] (4) Surface spraying: Spray the front and back surfaces of the paper sample obtained in step (3) with a 2.0% mass concentration of a diquaternary ammonium salt chitosan and bamboo nanocellulose composite liquid, wherein the absolute dry mass ratio of the diquaternary ammonium salt chitosan and bamboo nanocellulose is 6:4, and the outer surface spraying amount is 2.5 g / m 2 , and then use an electric infrared generator to infrared dry the paper sample at 140°C for 60 minutes to obtain paper sample B.

[0076] (5) Hot rolling treatment: The paper sample B obtained in step (4) was hot rolled at a temperature of 94° C. and a pressure of 22 MPa for 25 min, and then infrared dried at 65° C. for 15 min to obtain a bamboo fiber barrier packaging paper.

[0077] The performance indicators of the bamboo fiber barrier packaging paper prepared in this example are as follows: Basis weight: 47g / m 2 Tensile strength: 2.90kN / m; Tear strength: 678.2mN; Oxygen permeability: 523cm 3 / m 2 ·day·0.1MPa; Water vapor transmission rate: 156g / m 2 ·day; antibacterial rate: 90%.

[0078] Example 3

[0079] This embodiment provides a method for preparing bamboo fiber barrier packaging paper, and the specific preparation steps are as follows:

[0080] (1) Bamboo fiber compounding: Bleached sulfate bamboo fiber (BF, length 2-15 mm, diameter 27-52 μm) was beaten in a PFI mill at a beating speed of 5000 rpm, a beating concentration of 1.8 wt%, and a beating degree of 50°SR; bamboo shoot husk fiber (SF, length 5-20 mm, diameter 30-45 μm) was beaten in a PFI mill at a beating speed of 8000 rpm, a beating concentration of 2.2 wt%, and a beating degree of 58°SR. The beaten bleached sulfate bamboo fiber was then dispersed in an electric disperser at a speed of 5000 r / min for 20 min at a concentration of 2.0% by mass, and the beaten bamboo shoot husk fiber was dispersed in an electric disperser at a speed of 6000 r / min for 25 min at a concentration of 2.5% by mass. Finally, the bleached sulfate bamboo fiber dispersion obtained after the dispersion treatment and the bamboo shoot shell fiber dispersion were uniformly mixed at an absolute dry mass ratio of 6:4 to obtain a BF / SF mixed slurry solution.

[0081] (2) Filler addition: nano-antibacterial bamboo powder (BP) (particle diameter of 50 to 500 nm) was added to the BF / SF mixed slurry solution in step (1) under high-speed stirring (rotation speed: 5000 r / min). The amount of nano-antibacterial bamboo powder added was 3.5% of the absolute dry mass of the BF / SF / BP composite slurry. The mixture was mixed evenly to obtain a BF / SF / BP composite slurry.

[0082] (3) Papermaking process: The BF / SF / BP composite slurry obtained in step (2) is paper-formed on a rotary paper machine at a slurry concentration of 1.6 wt%, dehydrated, and dried to obtain paper sample A.

[0083] (4) Surface spraying: Spray the front and back surfaces of the paper sample obtained in step (3) with a 2.5% mass concentration of a composite liquid of diquaternary ammonium salt chitosan and bamboo nanocellulose, wherein the absolute dry mass ratio of diquaternary ammonium salt chitosan to bamboo nanocellulose is 6:4, and the outer surface spraying amount is 3.0 g / m 2 , and then use an electric infrared generator to infrared dry the paper sample at 170°C for 70 minutes to obtain paper sample B.

[0084] (5) Hot rolling treatment: The paper sample B obtained in step (4) was hot rolled at a temperature of 98° C. and a pressure of 23 MPa for 34 min, and then infrared dried at 75° C. for 25 min to obtain a bamboo fiber barrier packaging paper.

[0085] The performance indicators of the bamboo fiber barrier packaging paper prepared in this embodiment are as follows: Basis weight: 48g / m 2 Tensile strength: 3.03kN / m; Tear strength: 696.4mN; Oxygen permeability: 496cm 3 / m 2 ·day·0.1MPa; Water vapor transmission rate: 148g / m 2 ·day; antibacterial rate: 92%.

[0086] Example 4

[0087] This embodiment provides a method for preparing bamboo fiber barrier packaging paper, and the specific preparation steps are as follows:

[0088] (1) Bamboo fiber compounding: Bleached sulfate bamboo fiber (BF, length 2-15 mm, diameter 27-52 μm) was beaten in a PFI mill at 6000 rpm, a beating concentration of 2.0 wt%, and a beating degree of 55°SR; bamboo shoot husk fiber (SF, length 5-20 mm, diameter 30-45 μm) was beaten in a PFI mill at 9000 rpm, a beating concentration of 2.5 wt%, and a beating degree of 60°SR. The beaten bleached sulfate bamboo fiber was then dispersed in an electric disperser at a speed of 6000 r / min for 25 min at a concentration of 2.5% by mass, and the beaten bamboo shoot husk fiber was dispersed in an electric disperser at a speed of 7000 r / min for 30 min at a concentration of 3.0% by mass. Finally, the bleached sulfate bamboo fiber dispersion obtained after the dispersion treatment and the bamboo shoot shell fiber dispersion were uniformly mixed at an absolute dry mass ratio of 5:5 to obtain a BF / SF mixed slurry solution.

[0089] (2) Filler addition: nano-antibacterial bamboo powder (BP) (particle diameter of 50 to 500 nm) was added to the BF / SF mixed slurry solution in step (1) under high-speed stirring (rotation speed: 6000 r / min), wherein the amount of nano-antibacterial bamboo powder added was 5.0% of the absolute dry mass of the BF / SF / BP composite slurry, and the mixture was mixed uniformly to obtain a BF / SF / BP composite slurry.

[0090] (3) Papermaking process: The BF / SF / BP composite slurry obtained in step (2) is paper-formed on a rotary paper machine at a slurry concentration of 1.8 wt%, dehydrated, and dried to obtain paper sample A.

[0091] (4) Surface spraying: Spray the front and back surfaces of the paper sample obtained in step (3) with a 3.0% mass concentration of a composite liquid of diquaternary ammonium salt chitosan and bamboo nanocellulose, wherein the absolute dry mass ratio of diquaternary ammonium salt chitosan and bamboo nanocellulose is 7:3, and the outer surface spraying amount is 4.0 g / m 2 , and then use an electric infrared generator to infrared dry the paper sample at 200°C for 80 minutes to obtain paper sample B.

[0092] (5) Hot rolling treatment: The paper sample B obtained in step (4) was hot rolled at a temperature of 100° C. and a pressure of 25 MPa for 40 min, and then infrared dried at 80° C. for 30 min to obtain a bamboo fiber barrier packaging paper.

[0093] The performance indicators of the bamboo fiber barrier packaging paper prepared in this embodiment are as follows: Basis weight: 50g / m 2 Tensile strength: 3.16kN / m; Tear strength: 725.3mN; Oxygen transmission rate: 464cm 3 / m2 ·day·0.1MPa; Water vapor transmission rate: 132g / m 2 ·day; antibacterial rate: 95%.

[0094] Comparative Example 1

[0095] This comparative example provides a method for preparing bamboo fiber packaging paper, and the specific preparation steps are as follows:

[0096] (1) Bamboo fiber pulping: Bleached sulfate bamboo fiber (BF, length 2-15 mm, diameter 27-52 μm) was beaten in a PFI mill at 3000 rpm, a beating concentration of 1.0 wt%, and a beating degree of 40°SR. The beaten bleached sulfate bamboo fiber was then dispersed in an electric disperser at a speed of 3000 rpm for 10 min at a concentration of 1.0% by mass to obtain a BF bamboo fiber pulp solution.

[0097] (2) Filler addition: nano-antibacterial bamboo powder (BP) (particle diameter of 50 to 500 nm) was added to the BF bamboo fiber slurry solution in step (1) under high-speed stirring (rotation speed: 3000 r / min), and the amount of nano-antibacterial bamboo powder added was 1.0% of the absolute dry mass of the BF / BP composite slurry. The mixture was mixed evenly to obtain a BF / BP composite slurry.

[0098] (3) Papermaking process: The BF / BP composite slurry obtained in step (2) is paper-formed on a rotary paper machine at a slurry concentration of 1.2 wt%, dehydrated, and dried to obtain paper sample A.

[0099] (4) Surface spraying: Spray the front and back surfaces of the paper sample obtained in step (3) with a 1.5% mass concentration of a composite liquid of diquaternary ammonium salt chitosan and bamboo nanocellulose, wherein the absolute dry mass ratio of diquaternary ammonium salt chitosan and bamboo nanocellulose is 5:5, and the outer surface spraying amount is 1.5 g / m 2 , and then use an electric infrared generator to infrared dry the paper sample at 100°C for 50 minutes to obtain paper sample B.

[0100] (5) Hot rolling treatment: The paper sample B obtained in step (4) was hot rolled at a temperature of 90° C. and a pressure of 20 MPa for 20 min, and then infrared dried at 60° C. for 10 min to obtain a bamboo fiber barrier packaging paper.

[0101] The performance indicators of the bamboo fiber barrier packaging paper prepared in this comparative example are as follows: Basis weight: 46g / m 2 Tensile strength: 1.93kN / m; Tear strength: 568.4mN; Oxygen permeability: 674cm 3 / m 2·day·0.1MPa; Water vapor transmission rate: 235g / m 2 ·day; antibacterial rate: 86%.

[0102] Comparative Example 2

[0103] This comparative example provides a method for preparing bamboo fiber packaging paper, and the specific preparation steps are as follows:

[0104] (1) Bamboo fiber compounding: Bleached sulfate bamboo fiber (BF, length 2-15 mm, diameter 27-52 μm) was beaten in a PFI mill at 3000 rpm, a beating concentration of 1.0 wt%, and a beating degree of 40°SR; bamboo shoot husk fiber (SF, length 5-20 mm, diameter 30-45 μm) was beaten in a PFI mill at 6000 rpm, a beating concentration of 1.5 wt%, and a beating degree of 50°SR. The beaten bleached sulfate bamboo fiber was then dispersed in an electric disperser at a speed of 3000 r / min for 10 min at a concentration of 1.0% by mass, and the beaten bamboo shoot husk fiber was dispersed in an electric disperser at a speed of 4000 r / min for 15 min at a concentration of 1.5% by mass. Finally, the bleached sulfate bamboo fiber dispersion and the bamboo shoot shell fiber dispersion obtained after the dispersion treatment were uniformly mixed at an absolute dry mass ratio of 8:2 to obtain a BF / SF mixed slurry solution.

[0105] (2) Papermaking process: The BF / SF mixed slurry obtained in step (1) is paper-formed on a rotary paper machine at a slurry concentration of 1.2 wt%, dehydrated, and dried to obtain paper sample A.

[0106] (3) Surface spraying: Spray the front and back surfaces of the paper sample obtained in step (2) with a 1.5% mass concentration of a composite liquid of diquaternary ammonium salt chitosan and bamboo nanocellulose, wherein the absolute dry mass ratio of diquaternary ammonium salt chitosan and bamboo nanocellulose is 5:5, and the outer surface spraying amount is 1.5 g / m 2 , and then use an electric infrared generator to infrared dry the paper sample at 100°C for 50 minutes to obtain paper sample B.

[0107] (4) Hot rolling treatment: The paper sample B obtained in step (3) was hot rolled at a temperature of 90° C. and a pressure of 20 MPa for 20 min, and then infrared dried at 60° C. for 10 min to obtain a bamboo fiber barrier packaging paper.

[0108] The performance indicators of the bamboo fiber barrier packaging paper prepared in this comparative example are as follows: Basis weight: 45g / m 2 Tensile strength: 1.68kN / m; Tear strength: 557.4mN; Oxygen permeability: 641cm 3 / m2 ·day·0.1MPa; Water vapor transmission rate: 195g / m 2 ·day; antibacterial rate: 76%.

[0109] Comparative Example 3

[0110] This comparative example provides a method for preparing bamboo fiber packaging paper, and the specific preparation steps are as follows:

[0111] (1) Bamboo fiber compounding: Bleached sulfate bamboo fiber (BF, length 2-15 mm, diameter 27-52 μm) was beaten in a PFI mill at 3000 rpm, a beating concentration of 1.0 wt%, and a beating degree of 40°SR; bamboo shoot husk fiber (SF, length 5-20 mm, diameter 30-45 μm) was beaten in a PFI mill at 6000 rpm, a beating concentration of 1.5 wt%, and a beating degree of 50°SR. The beaten bleached sulfate bamboo fiber was then dispersed in an electric disperser at a speed of 3000 r / min for 10 min at a concentration of 1.0% by mass, and the beaten bamboo shoot husk fiber was dispersed in an electric disperser at a speed of 4000 r / min for 15 min at a concentration of 1.5% by mass. Finally, the bleached sulfate bamboo fiber dispersion and the bamboo shoot shell fiber dispersion obtained after the dispersion treatment were uniformly mixed at an absolute dry mass ratio of 8:2 to obtain a BF / SF mixed slurry solution.

[0112] (2) Filler addition: nano-antibacterial bamboo powder (BP) (particle diameter of 50 to 500 nm) was added to the BF / SF mixed slurry solution in step (1) under high-speed stirring (rotation speed: 3000 r / min), wherein the amount of nano-antibacterial bamboo powder added was 1.0% of the absolute dry mass of the BF / SF / BP composite slurry, and the mixture was mixed uniformly to obtain a BF / SF / BP composite slurry.

[0113] (3) Papermaking: The BF / SF / BP composite slurry obtained in step (2) was processed by sheeting, forming, dehydrating and drying on a rotary paper machine at a slurry concentration of 1.2 wt% to obtain a paper sample.

[0114] (4) Hot rolling treatment: The paper sample obtained in step (3) was hot rolled at a temperature of 90° C. and a pressure of 20 MPa for 20 min, and then infrared dried at 60° C. for 10 min to obtain a bamboo fiber barrier packaging paper.

[0115] The performance indicators of the bamboo fiber barrier packaging paper prepared in this comparative example are as follows: Basis weight: 45g / m 2 Tensile strength: 2.05kN / m; Tear strength: 574.8mN; Oxygen permeability: 623cm 3 / m 2·day·0.1MPa; Water vapor transmission rate: 207g / m 2 ·day; antibacterial rate: 68%.

[0116] The above embodiments are preferred implementations of the present invention, but the implementations 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 equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing bamboo fiber barrier packaging paper, characterized in that: The following steps are involved: (1) Bamboo fiber compound: The bleached sulfate bamboo fiber BF and the bamboo shoot shell fiber SF are respectively beaten to obtain a BF pulp with a beating degree of 40-55°SR and a SF pulp with a beating degree of 50-60°SR; the BF pulp and the SF pulp are then fully dispersed to obtain a BF dispersion and a SF dispersion; the BF dispersion and the SF dispersion are then evenly mixed to obtain a BF / SF mixed pulp; (2) Filler addition: adding bamboo powder BP to the BF / SF mixed slurry obtained in step (1) under stirring conditions, mixing evenly to obtain a BF / SF / BP composite slurry; (3) Papermaking: The BF / SF / BP composite slurry obtained in step (2) is subjected to papermaking, forming, dehydration, and drying to obtain paper sample I; (4) Surface spraying: The outer surface of the paper sample I obtained in step (3) is sprayed with a surface sizing agent, and then dried to obtain a paper sample II; wherein the surface sizing agent is a composite solution of diquaternary ammonium salt chitosan and bamboo nanocellulose; (5) Hot rolling treatment: hot rolling the paper sample II obtained in step (4), and then drying it to obtain a bamboo fiber barrier packaging paper; The bleached sulfate bamboo fiber BF described in step (1) has a length of 2 to 15 mm and a diameter of 27 to 52 μm; the bamboo shoot fiber SF has a length of 5 to 20 mm and a diameter of 30 to 45 μm; The mass ratio of the bleached sulfate bamboo fiber BF and the bamboo shoot shell fiber SF in step (1) is 5:5 to 8:2; The beating treatment conditions of the bleached sulfate bamboo fiber BF described in step (1) are: beating revolutions of 3000 to 6000 revolutions, and a beating concentration of 1.0 to 2.0 wt%; the beating treatment conditions of the bamboo shoot fiber SF are: beating revolutions of 6000 to 9000 revolutions, and a beating concentration of 1.5 to 2.5 wt%; The dispersion treatment of the BF slurry described in step (1) is achieved by the following method: the BF slurry is dispersed at a concentration of 1.0 to 2.5% by mass at a rotation speed of 3000 to 6000 r / min for 10 to 25 minutes; The dispersion treatment of the SF slurry in step (1) is achieved by: dispersing the SF slurry at a concentration of 1.5 to 3.0% by mass at a rotation speed of 4000 to 7000 r / min for 15 to 30 minutes; The amount of bamboo powder BP added in step (2) is 1.0-5.0% of the mass of the BF / SF / BP composite slurry; The slurry concentration of the BF / SF / BP compound slurry described in step (3) is 1.2-1.8% by mass; The mass ratio of diquaternary ammonium salt chitosan and bamboo nanocellulose in the surface sizing agent described in step (4) is 5:5 to 7:3; The concentration of the surface sizing agent in step (4) is 1.5 to 3.0% by mass; The amount of the surface sizing agent sprayed on the outer surface in step (4) is 1.5 to 4.0 g / m 2 ; The drying method in step (4) is: infrared drying at 100-200°C for 50-80 minutes; The hot rolling conditions in step (5) are: temperature of 90-100°C, pressure of 20-25 MPa, and time of 20-40 min; The drying method in step (5) is: infrared drying at 60-80°C for 10-30 minutes; The bamboo powder BP described in step (2) is a nano-scale antibacterial bamboo powder with a particle diameter of 50 to 500 nm; it is prepared by the following method: Bamboo slices of Phyllostachys pubescens are mechanically crushed at room temperature and 3000-5000 rpm to obtain bamboo powder; the bamboo powder is then immersed in an antibacterial solution containing quaternary ammonium chitosan and then dried to obtain nano-scale antibacterial bamboo powder; The antibacterial liquid containing quaternary ammonium chitosan is prepared by the following method: dissolving quaternary ammonium chitosan and polyethylene glycol in water respectively, and then mixing them together, controlling the solid content of the quaternary ammonium chitosan to be 5%, to obtain the antibacterial liquid containing quaternary ammonium chitosan; The mass ratio of the quaternary ammonium chitosan to the polyethylene glycol is 1-5:6-10; The immersion time is 30 to 180 minutes.

2. The method for preparing the bamboo fiber barrier packaging paper according to claim 1, characterized in that: The stirring speed in step (2) is 3000-6000 r / min.

3. A bamboo fiber barrier packaging paper, characterized by: It is prepared by the method according to any one of claims 1 to 2.

4. Use of the bamboo fiber barrier packaging paper according to claim 3 in packaging materials.

5. The use according to claim 4, characterized in that: The packaging material is mildew-proof packaging material.

6. The use according to claim 5, characterized in that: The packaging material is a mildew-proof packaging material used for packaging grain.

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