Method for producing bamboo pulp culture paper

Abstract

The embodiment of the application provides a preparation method of bamboo pulp culture paper, comprising the following steps: S1: providing bamboo pulp slurry and fine components; S2: grinding the fine components to form first slurry; S3: mixing the bamboo pulp slurry and the first slurry according to a dry weight mass ratio of 70-90:10-30 to form mixed slurry, wherein the beating degree of the mixed slurry is 36-40°SR, and the bamboo pulp slurry is separately beaten; and S4: obtaining the bamboo pulp culture paper through papermaking, surface sizing and drying of the mixed slurry, wherein the performance indexes of the culture paper formed through the above steps are greatly increased, and research shows that a large number of micro-fibers appear after the fine components are ground by zirconium oxide beads, the addition of the micro-fibers into the slurry can significantly increase the bonding strength between fibers, which leads to the increase of folding endurance and breaking length, and on the one hand, the bamboo pulp fibers can be fully utilized, and on the other hand, the fine components formed in the papermaking process can be treated.

Description

Technical Field

[0001] This invention relates to a method for preparing bamboo pulp cultural paper. Background Technology

[0002] my country has scarce timber resources, especially softwood pulp, which usually needs to be imported. However, my country is rich in bamboo resources, so there is a huge market demand for using bamboo fiber to make paper or fluff pulp. However, there are currently some problems in the process of using bamboo fiber to make paper or fluff pulp. Because bamboo fibers are long and thin, with an average fiber length of about 2.0 mm, which is between the length of hardwood and softwood fibers, and a width of 15-18 μm, thick walls, small cavities, high density, and relatively stiff fibers, there are many impurities and fine particles. Therefore, screening is usually required during papermaking or fluff pulp production to remove impurities and fine particles from the bamboo pulp. In some cases, the dry weight of these impurities and fine particles can reach about 20% of the dry weight of the pulp before screening. If these impurities and fine particles cannot be utilized, it will result in a significant waste of fiber resources.

[0003] Therefore, a solution needs to be developed and implemented to address the aforementioned technical problems. Summary of the Invention

[0004] Therefore, the present invention provides a method for preparing bamboo pulp cultural paper to solve the above-mentioned technical problems.

[0005] A method for preparing bamboo pulp cultural paper, characterized by comprising the following steps:

[0006] S1: Provides bamboo pulp and fine components;

[0007] S2: Grind the fine components to form the first slurry;

[0008] S3: Mix bamboo pulp with the first pulp at a dry weight ratio of 70-90:10-30 to form a mixed pulp. The mixed pulp has a beating degree of 36-40°SR, and the bamboo pulp is beating separately.

[0009] S4: The mixed pulp is processed through papermaking, surface sizing, and drying to obtain bamboo pulp cultural paper.

[0010] Step S2 includes the following specific steps:

[0011] S21: Add water to the fine fraction to prepare a fine fraction slurry with a concentration of 0.9% to 2.0%.

[0012] S22: Grind the finely divided slurry using zirconium oxide particles, wherein the zirconium oxide particles have a particle size of 2-3 mm and the grinding time is 10-30 min.

[0013] The bamboo pulp is either unscreened or screened.

[0014] The bamboo pulp is a screened bamboo pulp, and the following steps are included before step S1:

[0015] S111: Screening is performed on unscreened bamboo pulp to obtain screened bamboo pulp and fine fractions.

[0016] In step S3, the bamboo pulp and the first pulp are mixed in a dry weight ratio of 75-83:17-25.

[0017] The bamboo pulp is unscreened bamboo pulp, and the following steps are included before step S1:

[0018] S121: The bamboo pulp is divided into a first bamboo pulp and a second bamboo pulp. The second bamboo pulp is screened to obtain fine fractions and a second screened pulp. The first bamboo pulp is used in step S1 as the bamboo pulp.

[0019] S122: Use the second screened pulp to prepare tissue paper or fluff pulp.

[0020] In step S3, the bamboo pulp and the first pulp are mixed at a dry weight ratio of 70-80:20-30.

[0021] The content of impurity cells in the aforementioned fine components is greater than or equal to 65%.

[0022] The fine particles mentioned above are those that can be obtained by passing through a sieve with a mesh size of 0.5mm-1.0mm during the screening process.

[0023] During the papermaking process, the concentration of the mixed pulp is 0.5%-1.0%.

[0024] Beneficial Effects: This invention provides a method for preparing bamboo pulp cultural paper, comprising the following steps: S1: providing bamboo pulp and fine components; S2: grinding the fine components to form a first pulp; S3: mixing the bamboo pulp and the first pulp at a dry weight ratio of 70-90:10-30 to form a mixed pulp, the mixed pulp having a beating degree of 36-40°SR, and the bamboo pulp being beated separately; S4: the mixed pulp undergoing papermaking, surface sizing, and drying to obtain bamboo pulp cultural paper. The cultural paper formed by the above method exhibits significantly improved performance indicators. Research has found that after grinding the fine components with zirconia beads, a large number of broom-like microfibers appear. Adding these to the pulp significantly increases the bonding strength between fibers, leading to increased folding endurance and breaking length. This method not only fully utilizes bamboo pulp fibers but also allows for the processing of fine components formed during other papermaking processes. Attached Figure Description

[0025] Figures 1-3 Micrograph of fine components in the first slurry. Detailed Implementation

[0026] In the following description, the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] This invention provides a method for preparing bamboo pulp cultural paper, comprising the following steps:

[0028] S1: Provides bamboo pulp and fine fractions.

[0029] Specifically, the bamboo pulp is usually made from bamboo materials such as moso bamboo, nan bamboo, ci bamboo, and large bamboo, and is a fiber raw material obtained through the sulfate process or caustic soda process. At the same time, the bamboo pulp can be unbleached bamboo pulp or bleached bamboo pulp. In addition, the average fiber length of the bamboo pulp is 1.5mm to 2.8mm, and the bamboo pulp can be unscreened bamboo pulp or screened bamboo pulp.

[0030] The sieved bamboo pulp refers to bamboo pulp that has undergone sieving treatment. The sieving treatment refers to the process of removing fine particles from bamboo pulp by sieving using a sieving device as shown in documents such as CN113622212A. It can be understood that unscreened bamboo pulp refers to bamboo pulp that has not undergone the above-mentioned treatment process.

[0031] Meanwhile, the aforementioned fine particles refer to fine particles obtained through sieving.

[0032] In this application, the fine components refer to components that can pass through a 0.5mm sieve. The sieved bamboo pulp can be a pulp that has undergone sieving to remove components smaller than 0.5mm. In another embodiment, the sieved bamboo pulp is a pulp that has undergone sieving to remove components smaller than 1.0mm. The fine components refer to components that have passed through a 1.0mm sieve.

[0033] The fine particles contain at least 65% impurities, and further, the fine particles contain at least 80% impurities.

[0034] Furthermore, when the bamboo pulp is screened bamboo pulp, the following steps are included before step S1:

[0035] S111: Screening is performed on unscreened bamboo pulp to obtain screened bamboo pulp and fine fractions.

[0036] Furthermore, when the bamboo pulp is unscreened bamboo pulp, the following steps are included before step S1:

[0037] S121: The bamboo pulp is divided into a first bamboo pulp and a second bamboo pulp. The second bamboo pulp is screened to obtain fine fractions and a second screened pulp. The first bamboo pulp is used in step S1 as the bamboo pulp.

[0038] S122: Use the second screened pulp to prepare tissue paper or fluff pulp.

[0039] Understandably, before step S1, there is also a step of pulping the fiber raw material to form unscreened bamboo pulp. Typically, the fiber raw material is dispersed in water by the mechanical action of a pulping device to form a fiber suspension. Understandably, when the fiber raw material is bamboo fiber raw material, such as bamboo pulp board, bamboo pulp is formed by a pulping device, which can be a hydraulic pulper.

[0040] S2: Grind the fine components to form the first slurry.

[0041] Specifically, it includes the following steps:

[0042] S21: Add water to the fine fraction to prepare a fine fraction slurry with a concentration of 0.9% to 2.0%.

[0043] S22: Grind the finely divided slurry using zirconium oxide particles, wherein the zirconium oxide particles have a particle size of 2-3 mm and the grinding time is 10-30 min.

[0044] Please refer to this as well. Figures 1-3 Studies have found that after fine components are ground by zirconium oxide particles, a large number of broom-like microfibers appear. Adding them to the slurry can significantly increase the bonding strength between fibers. At the same time, the grinding time should be controlled within the above range. If it is too long, the particle size of the fine components will be too small after grinding, and the retention rate will be greatly reduced. If the grinding time is too short, suitable broom-like microfibers cannot be formed.

[0045] S3: Mix bamboo pulp with the first pulp at a dry weight ratio of 70-90:10-30 to form a mixed pulp. The mixed pulp has a beating degree of 36-40°SR, and the bamboo pulp is beating separately.

[0046] Furthermore, when the bamboo pulp is unscreened bamboo pulp, the dry weight ratio of the bamboo pulp to the first pulp is 70-85:15-30.

[0047] Furthermore, when the bamboo pulp is screened bamboo pulp, the dry weight ratio of the bamboo pulp to the first pulp is 75-90:10-25.

[0048] S4: The mixed pulp is processed through papermaking, surface sizing, and drying to obtain bamboo pulp cultural paper.

[0049] The preparation method of the bamboo pulp cultural paper of the present invention will be further explained below with reference to specific embodiments.

[0050] Example 1:

[0051] S101: Provide bamboo pulp and fine particles, wherein the bamboo pulp is unscreened bamboo pulp and the fine particles are fine particles smaller than 0.5mm obtained by processing with the screening device shown in CN113622212A.

[0052] The content of impurities in this small fraction is greater than or equal to 90%.

[0053] S102: Grind the fine components to form the first slurry.

[0054] The fine fractions were mixed with water to prepare a 1% concentration fine fraction slurry. Then, the fine fraction slurry was ground using zirconia particles with a particle size of 2-3 mm for 20 minutes.

[0055] S103: Mix bamboo pulp and the first pulp at a dry weight ratio of 80:20 to form a mixed pulp with a beating degree of 38°SR.

[0056] S104: The mixed pulp is processed through papermaking, surface sizing, and drying to obtain bamboo pulp cultural paper. During the papermaking process, the pulp concentration is 0.7%.

[0057] Comparative Example 1:

[0058] Using the unscreened bamboo pulp from step S101, bamboo pulp cultural paper is obtained through beating, papermaking, surface sizing, and drying. The beating degree is the same as in step S103, and the papermaking, surface sizing, and drying steps are the same as in step S104.

[0059] The tests conducted on Example 1 and Comparative Example 1 are as follows.

[0060] project unit Comparative Example 1 Example 1 Quantitative <![CDATA[g / m 2 ]]> 63.9 62.6 Smoothness s 1.8 3 flexural strength / Second-rate 55 166 stiffness mN.m 66 53 Discontinuity m 3602 4925

[0061] The above test items are tested using the following methods.

[0062] Basis weight: The test method of GB / T 451.2-2002 Determination of basis weight of paper and paperboard was adopted.

[0063] Smoothness: The test method of GB / T 456-2002 Determination of smoothness of paper and paperboard (Beck method) is adopted.

[0064] Folding endurance: The test method of GB / T457-2008 Determination of folding endurance of paper and paperboard shall be adopted.

[0065] Stiffness: The test method of GB / T 2679.3-1996 "Determination of stiffness of paper and paperboard" was adopted.

[0066] Breaking length: The breaking length was tested using the method specified in GB / T 12914-2018 "Determination of tensile strength of paper and paperboard - constant speed tensile test (20 mm / min)".

[0067] Based on the above test data, after adding finely ground components from zirconia beads to unscreened bamboo pulp, the smoothness increased from 1.8S to 3S, an increase of 66.7%; the folding endurance increased from 55 times to 166 times, an increase of 201%; and the breaking length increased from 3602m to 4925m, an increase of 36.7%. All indicators showed a significant increase, except for stiffness, which decreased from 66 to 53, a decrease of 19.7%. The study found that after the finely ground components were ground by zirconia beads, a large number of broom-like microfibers appeared. Adding them to the pulp significantly increased the bonding strength between fibers, which led to an increase in folding endurance and breaking length. At the same time, because the finely ground components filled a large number of gaps between pulp fibers, the porosity of the paper decreased, thus increasing the density. The stiffness also decreased as the paper density increased.

[0068] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing bamboo pulp cultural paper, characterized in that, Includes the following steps: S1: Provides bamboo pulp and fine components; S2: Grind the fine components to form the first slurry; S3: Mix bamboo pulp with the first pulp at a dry weight ratio of 70-90:10-30 to form a mixed pulp. The mixed pulp has a beating degree of 36-40°SR, and the bamboo pulp is beating separately. S4: The mixed pulp is processed through papermaking, surface sizing, and drying to obtain bamboo pulp cultural paper; Step S2 includes the following specific steps: S21: Add water to the aforementioned fine fractions to prepare a fine fraction slurry with a concentration of 0.9% to 2.0%; S22: The finely divided slurry is ground using zirconium oxide particles, wherein the zirconium oxide particles have a particle size of 2-3 mm and the grinding time is 10-30 min. The bamboo pulp is a screened bamboo pulp, and the following steps are included before step S1: S111: Unscreened bamboo pulp is screened to obtain screened bamboo pulp and fine components, wherein the content of impurity cells in the fine components is greater than or equal to 65%; The fine particles mentioned are those that can be obtained by passing through a sieve with a mesh size of 0.5mm-1.0mm during the screening process.

2. The preparation method according to claim 1, characterized in that, In step S3, the bamboo pulp and the first pulp are in a dry weight ratio of 70-85:15-30.

3. The preparation method according to claim 2, characterized in that, The bamboo pulp is unscreened bamboo pulp, and the following steps are included before step S1: S121: The bamboo pulp is divided into a first bamboo pulp and a second bamboo pulp. The second bamboo pulp is screened to obtain fine fractions and a second screened pulp. The first bamboo pulp is used in step S1 as the bamboo pulp. S122: Use the second screened pulp to prepare tissue paper or fluff pulp.

4. The preparation method according to claim 1, characterized in that, During the papermaking process, the concentration of the mixed pulp is 0.5%-1.0%.

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