A plant-based pore-controllable high-strength filter paper base and its preparation and application

Abstract

The present invention discloses a preparation method and application of a plant-based high-strength filter paper with controllable pore size. The method comprises the following steps: mixing bamboo pulp fibers and fine fibers in a mass ratio of (100-80): (0-20), and drying the mixture naturally without pressure to obtain filter paper. The fine fibers refer to plant fibers with a diameter of less than 10 μm. By adding fine fibers to bamboo pulp fibers, the present invention not only reduces the maximum pore size and average pore size of the filter paper base while ensuring good air permeability, but also greatly improves the tensile index of the filter paper base, which is several times that of commercial coniferous wood pulp. This provides a certain theoretical basis and technical support for the high-value application of bamboo pulp in special filter paper.

Description

Technical Field

[0001] The invention relates to the technical field of special paper processing, and in particular to a plant-based high-strength filter paper base with controllable pore size and a preparation method and application thereof. Background Art

[0002] Bamboo pulp fibers are slender, stiff, thick, small, and evenly surfaced. The cellulose content is 50% to 60%. The fiber morphology and content are similar to those of wood for papermaking. The performance of bamboo pulp is between that of coniferous wood pulp and broadleaf wood pulp. The paper has high bulk and good air permeability, making it a good alternative source of wood pulp for filtration. Fine fibers have a smaller diameter, and their diameters are all less than 10 μm when observed under an electron microscope. The smaller diameter allows more hydrogen bonds to be formed between the fibers, making the fibers more tightly connected and resulting in better papermaking performance.

[0003] Filter paper is a special paper with a loose porous structure formed by wet forming using one or more of plant fiber, inorganic fiber and synthetic fiber as raw materials. The plant fiber used to produce filter paper is mainly various types of wood pulp, cotton pulp, hemp, reed fiber, etc. For example, the filter paper preparation methods disclosed in CN 102230297A (agents for modifying plant pulp fibers and modification methods thereof, filter paper and preparation methods thereof) and CN 102953295B (preparation method of high-strength cured filter paper) all require the use of mercerized coniferous wood pulp. Although mercerized coniferous wood pulp fibers are round and elastic, the paper has high bulk and high air permeability, which can give filter paper excellent filtering performance, the average pore size of mercerized pulp is too large and the strength is particularly poor, and most of the existing coniferous wood pulp fibers are imported and costly.

[0004] Therefore, there is an urgent need to provide a filter paper with low cost, small pore size, high air permeability and high strength. Summary of the invention

[0005] In view of the shortcomings and deficiencies of the above prior art, the primary purpose of the present invention is to provide a method for preparing a plant-based high-strength filter paper base with controllable pore size.

[0006] Another object of the present invention is to provide a plant-based high-strength filter paper with controllable pore size that is efficiently prepared by the above method.

[0007] Another object of the present invention is to provide the use of the above-mentioned plant-based pore-controllable high-strength filter paper base paper in filter materials, thereby replacing imported coniferous wood fibers.

[0008] The present invention is achieved through the following technical solutions:

[0009] A method for preparing a plant-based filter paper with controllable pore size and high strength, characterized in that bamboo pulp fiber and fine fiber are mixed in a mass ratio of (100-80): (0-20), dispersed for 3000-6000r, and then made into paper, and dried to obtain the plant-based filter paper with controllable pore size and high strength;

[0010] The fine fibers refer to plant fibers with a diameter of less than 10 μm.

[0011] Preferably, the bamboo pulp fibers and fine fibers are sieved; the sieving refers to sieving out fibers with a mesh size of less than 30.

[0012] Preferably, the debonding and dispersion is carried out using a fiber standard disintegrator at 3000±500 rpm.

[0013] Preferably, the basis weight of the paper is 100±3 g / m 2 .

[0014] Preferably, the drying temperature is 120-130°C.

[0015] Preferably, the fine fibers are one or more of straw fibers, yellow cedar fibers, and ula grass fibers.

[0016] Preferably, the bamboo pulp fiber is one or more of sweet bamboo fiber and hanging bamboo fiber.

[0017] Preferably, the bamboo pulp fiber is sweet bamboo fiber, and the mass ratio of the sweet bamboo fiber to the fine fiber is (95-80):(5-20).

[0018] The plant-based high-strength filter paper base with controllable pore size prepared by the method of the present invention.

[0019] The invention discloses an application of the plant-based high-strength filter paper with controllable pore size in filter materials.

[0020] Compared with existing products, the present invention has the following advantages and beneficial effects:

[0021] (1) The filter paper base paper prepared by the present invention not only improves the physical properties of the paper such as the tensile index, but also can adjust the maximum pore size and average pore size of the paper, while ensuring good air permeability of the paper, thereby meeting the production requirements of the filter paper.

[0022] (2) The present invention uses bamboo pulp fiber and fine fiber as raw materials, replacing the more expensive coniferous wood pulp fiber, and can also promote the development of the bamboo industry and alleviate the problem of shortage of pulp and paper resources.

[0023] (3) The preparation method of the present invention has low operating difficulty, simple process, low energy consumption, and no need to perform mercerization modification on the fiber. At the same time, it can improve the filtering performance of the filter paper and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the SEM image of the straw fiber used in Example 1.

[0025] Figure 2 This is the SEM image of the cork wood fiber used in Example 2.

[0026] Figure 3 This is the SEM image of the Ula grass fiber used in Example 3. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0028] Example 1

[0029] The preparation method of the plant-based high-strength filter paper with controllable pore size in this embodiment is as follows:

[0030] Take 10g of absolutely dry bamboo / straw fiber and screen it through a Paul sifter for 10 minutes, then select 30g of fiber, wring it out, rub it into the size of millet grains, and place it in a freezer to balance the moisture for 24 hours. Take 2.826g of the absolutely dry mass of 30g of three-year-old bamboo fiber after screening and 0.314g of the absolutely dry mass of straw fiber after screening, so that the mass ratio of bamboo fiber to straw fiber is 90:10. After mixing the two fibers together, use a fiber standard disintegrator to disperse them at 3000rpm for 3000r, and automatically form them through an automatic Kaiser sheet making machine, and naturally dry them on a 120°C flat dryer to obtain filter paper 1. The fine fibers in this embodiment are straw fibers, and their diameter is less than 10μm. See the SEM picture. Figure 1 .

[0031] Example 2

[0032] The preparation method of the plant-based high-strength filter paper with controllable pore size in this embodiment is as follows:

[0033] Take 10g of absolutely dry sweet bamboo / Phellodendron chinense fiber and screen it through a Paul sifter for 10 minutes, then select 30g of the fiber, wring it out, rub it into the size of millet grains, and place it in a freezer to balance the moisture for 24 hours. Take 30g of the absolutely dry mass of four-year-old sweet bamboo fiber and 0.157g of the absolutely dry mass of Phellodendron chinense fiber after screening, so that the mass ratio of sweet bamboo fiber to Phellodendron chinense fiber is 95:5. After mixing the two fibers together, use a fiber standard disintegrator to disperse them at 3000rpm for 3000r, and automatically form them through an automatic Kaiser sheeter, and naturally dry them on a 130°C flat dryer to obtain filter paper 2. The fine fibers in this embodiment are Phellodendron chinense fibers, and their diameter is less than 10μm. See the SEM picture. Figure 2 .

[0034] Example 3

[0035] The preparation method of the plant-based high-strength filter paper with controllable pore size in this embodiment is as follows:

[0036] Take 10g of absolutely dry sweet bamboo / Ula grass fiber and screen it through a Paul sifter for 10 minutes, then select 30g of the fiber, wring it out, rub it into the size of millet grains, and place it in a freezer to balance the moisture for 24 hours. Take 2.983g of the absolutely dry mass of 30g of four-year-old sweet bamboo fiber after screening and 0.157g of the absolutely dry mass of 30g of Ula grass fiber after screening, so that the mass ratio of sweet bamboo fiber to Ula grass fiber is 95:5. After mixing the two fibers together, use a fiber standard disintegrator to disperse them at 3000rpm for 3000r, and automatically form them through an automatic Kaiser sheet making machine, and naturally dry them on a 120°C flat dryer to obtain filter paper 3. The fine fibers in this embodiment are Ula grass fibers, and their diameter is less than 10μm. See the SEM picture. Figure 3 .

[0037] Comparative Example 1

[0038] This comparative example refers to the preparation method of Example 1, except that the filter paper raw material is bamboo fiber, and no straw fiber is added.

[0039] Comparative Example 2

[0040] This comparative example refers to the preparation method of Example 1, except that the filter paper is originally made of bamboo fiber and straw fiber in a mass ratio of 70:30.

[0041] Comparative Example 3

[0042] This comparative example refers to the preparation method of Example 1, except that the filter paper is originally made of bamboo fiber and straw fiber in a mass ratio of 30:70.

[0043] Comparative Example 4

[0044] This comparative example refers to the preparation method of Example 2, except that the raw material fiber of the filter paper is sweet bamboo fiber, and no cork fiber is added.

[0045] Comparative Example 5

[0046] This comparative example refers to the preparation method of Example 2, except that the filter paper raw materials are sweet bamboo fiber and yellow cedar wood fiber with a mass ratio of 80:20.

[0047] Comparative Example 6

[0048] This comparative example refers to the preparation method of Example 3, except that the filter paper raw materials are sweet bamboo fiber and Ula grass fiber with a mass ratio of 85:15.

[0049] Comparative Example 7

[0050] This comparative example is commercial coniferous wood pulp, and the filter paper raw material is 100% commercial coniferous wood mercerized pulp.

[0051] Examples 1 to 3 and Comparative Examples 1 to 7 were tested, and the test results obtained are shown in Table 1:

[0052] The smaller the pore size of the filter paper, the higher its filtration efficiency; the higher the air permeability of the filter paper, the lower its filtration resistance. The strength of the filter paper is reflected by the tensile strength. It can be seen from Example 1 and Comparative Examples 1-3 that after adding 10%, 30% and 70% of straw fiber, the maximum pore size and average pore size both decrease, and the tensile index increases; but the air permeability of the base paper with 30% and 70% straw fiber seriously decreases, which does not meet the production requirements of the filter paper base paper. It can be seen from Example 2, Comparative Examples 4 and 5 that after adding 5% and 20% of Phellodendron chinense fiber, the maximum pore size and average pore size decrease significantly, and the tensile index is 1.42 times and 2.05 times that of the base paper without Phellodendron chinense fiber. It can be seen from Example 3, Comparative Examples 4 and 6 that after adding 5% and 15% of Ula grass fiber, the maximum pore size and average pore size decrease significantly, and the tensile index is 1.51 times and 2.82 times that of the base paper without Ula grass fiber. The tensile index of Examples 1 to 3 and Comparative Examples 1 to 6 are better than that of Comparative Example 7 (commercial softwood pulp). The test results show that with the increase of the amount of fine fiber added, the filter paper production requirements are met while ensuring the air permeability of the paper, the maximum pore size and average pore size of the paper are significantly reduced, and the tensile index is significantly increased.

[0053] Table 1 Performance test results

[0054]

[0055] *The unit mm / s is equivalent to L / m 2 ·s.

[0056] Depend on Figure 1-Figure 3 It can be seen that the diameters of rice straw fibers, yellow cedar fibers, and ula grass fibers are all below 10 μm.

[0057] 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 deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing a plant-based high-strength filter paper with controllable pore size, characterized in that: Prepare as follows: 10g of absolutely dry sweet bamboo / Phellodendron chinense fiber was screened by Paul sifter for 10min, and 30g of the fiber was wrung out and rolled into the size of millet grains, and then placed in a freezer for 24h to balance the moisture; 30g of the absolutely dry mass of four-year-old sweet bamboo fiber and 0.157g of the absolutely dry mass of Phellodendron chinense fiber were taken after screening, so that the mass ratio of sweet bamboo fiber to Phellodendron chinense fiber was 95:5, and the two fibers were mixed together, and then dispersed for 3000r at 3000rpm using a fiber standard disintegrator, and automatically formed by an automatic Kaiser sheeter, and naturally dried on a 130℃ flat plate dryer to obtain filter paper; or: Take 10g of absolutely dry sweet bamboo / Ula grass fiber and screen it through a Paul sifter for 10 minutes, then select 30g of the fiber, wring it out, rub it into the size of millet grains, and place it in a refrigerator to balance the moisture for 24 hours; take 2.983g of the absolutely dry mass of 30g of four-year-old sweet bamboo fiber and 0.157g of the absolutely dry mass of 30g of Ula grass fiber after screening, so that the mass ratio of sweet bamboo fiber to Ula grass fiber is 95:5, mix the two fibers together, use a fiber standard disintegrator at 3000rpm to disintegrate and disperse for 3000r, use an automatic Kaiser sheeter to automatically form, and naturally dry on a 120℃ flat dryer to obtain filter paper.

2. The plant-based high-strength filter paper with controllable pore size prepared by the method of claim 1.

3. Application of the plant-based high-strength filter paper with controllable pore size as described in claim 2 in filter materials.

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