A paper-based material with uniform internal micropore distribution and a method for preparing the same

Abstract

The application discloses a paper-based material with uniform internal micropore distribution and a preparation method thereof. The preparation method comprises the steps of pulping, beating, preparing a pore-releasing agent solution, blending, swelling treatment and micropore drying treatment. The paper-based material provided by the application has uniform internal micropore distribution and good elasticity, and is a green and environment-friendly paper-based material which is renewable, degradable and recyclable. The paper-based material with uniform internal micropore distribution has more fine pores and higher energy dissipation characteristics compared with traditional paper-based materials. The microporous paper-based material takes long fibers as a skeleton, and short fibers are filled in the skeleton to form a three-dimensional microporous paper-based material with long and short fibers interwoven with each other, and can be used in the fields of building, packaging and noise reduction.

Description

TECHNICAL FIELD

[0001] The present application relates to a paper-based material with uniform internal micro-pore distribution and its preparation method, belonging to the technical field of paper-based materials. BACKGROUND

[0002] In modern industry and daily life, porous paper-based materials are widely used in construction, packaging, soundproofing, and other fields due to their lightweight, high porosity, and good thermal insulation and sound absorption properties. With the increasing awareness of environmental protection and the demand for sustainable development, researchers have been seeking more environmentally friendly and performance-optimized paper-based material preparation methods.

[0003] Currently, the preparation of porous paper-based materials usually relies on multiple raw materials and complex formulations. These methods often require a large amount of chemical additives and complex process steps, resulting in high raw material costs, complex formulations, and high technical level requirements for operators, which limits the possibility of large-scale commercial application.

[0004] In particular, the existing technology often has the following problems when preparing porous paper-based materials:

[0005] 1. Too many raw materials, complex formulations, and poor operability: In the traditional preparation process of porous paper-based materials, multiple chemical additives and auxiliaries (especially plastic-based non-degradable additives) are required. These components not only increase production costs but also make the entire preparation process complex, difficult to control, and environmentally unfriendly. In addition, complex formulations require higher technical levels for operators, which is not conducive to the improvement of production efficiency and the stability of quality.

[0006] 2. Non-uniform pore distribution of prepared material products, with varying sizes of cavities or straight-through holes: The porous materials prepared by existing technology often have non-uniform pore structure problems, which can lead to inconsistent mechanical properties and thermal insulation performance of the materials, affecting their performance in actual applications. Varying sizes of cavities can also become weaknesses of the materials, reducing their overall durability and reliability. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a preparation method for micro-porous paper-based materials that simplifies the raw material formulation, improves the simplicity and controllability of operation, and ensures that the prepared paper-based materials have good uniformity of pore structure to meet the needs of different application scenarios.

[0008] To solve the above problems, the present application adopts the following technical solutions:

[0009] A preparation method for a paper-based material with uniform internal micro-pore distribution, characterized by comprising the following steps:

[0010] Step 1), Pulping: Put the paper pulp into a pulper and add tap water, and use a machine to break the paper pulp;

[0011] Step 2), Refining: Grind the paper pulp obtained in step 1) to obtain a slurry;

[0012] Step 3), Preparation of pore releasing agent solution: Mix glycerol, sodium bicarbonate and deionized water to prepare a pore releasing agent solution;

[0013] Step 4), Blending: Put the slurry prepared in step 2) into a stirrer, first add the pore releasing agent solution prepared in step 3), and stir and mix; then soak, so that the pore releasing agent fully combines with the paper pulp fibers;

[0014] Step 5), Swelling treatment: Stir the mixed slurry prepared in step 4) again to make it uniform, control the stirring speed of the stirrer, add sodium dodecyl sulfate after mixing, adjust the stirring speed of the stirrer to make the mixed paper pulp in the stirrer react with air, and make its volume swell;

[0015] Step 6), Microporous drying treatment: Immediately put the swollen paper pulp prepared in step 5) into a mold and place it in an oven for microporous drying treatment to obtain a microporous paper-based material.

[0016] Preferably, in step 1), the paper pulp is a mixture of waste paper pulp and coniferous wood pulp board; the weight ratio of the waste paper pulp to the coniferous wood pulp board is 2:8 to 4:6; the tap water is clean and free of fine particles, and the pH is 7.5 to 8.0.

[0017] Preferably, in step 1), the mechanical breaking uses a pulper, and the rotating speed of the pulper is 2000 to 3000 r / min, and the time is 20 to 40 min.

[0018] Preferably, in step 2), the grinding uses a refiner, and the rotating speed of the refiner is 2500 to 2800 r / min, and the circulating grinding time is 20 min.

[0019] Preferably, in step 3), the mass concentration of the pore releasing agent solution is 10% to 15%; wherein the addition amount of glycerol is controlled to be 5% to 10%, and the addition amount of sodium bicarbonate is controlled to be 5% to 10%.

[0020] Preferably, in step 4), the mass concentration of the slurry in the stirrer is controlled to be 3% to 7%, the addition amount of the pore releasing agent solution is controlled to be 0.5wt% to 1.5wt%, the rotating speed of the stirrer is controlled to be 500 to 700 r / min, and the stirring and mixing time is controlled to be 10 to 15 min; the soaking time is 30 to 60 min.

[0021] Preferably, the step 5) is specifically: the mixed slurry prepared in step 4) is stirred again, the stirring speed of the stirrer is controlled to be 200-300 r / min, and the mixed stirring is performed for 10-20 min; the stirring speed of the stirrer is reduced to 150-200 r / min, and after the sodium dodecyl sulfate is added, the mixing is performed for 2 min; then the stirring speed is controlled to be 400-560 r / min; the mixed slurry is expanded by stirring for 3-6 min, and the swelling treatment of the paper pulp is completed; the sodium dodecyl sulfate is a solution with a mass concentration of 1%-5%.

[0022] Preferably, in the step 6), the microporous drying treatment process is: in the first step, the oven temperature is controlled to be 90-110 ℃, and the drying time is 30-40 min; in this process, the sodium bicarbonate in the pore releasing agent which is combined with the swollen paper pulp fibers is gradually decomposed to generate gas, which offsets the influence of the collapse of the fiber space structure caused by the elimination of the bubbles of the swollen paper pulp, slowly releases the gas, extends the time for the fibers to maintain the initial shape position while offsetting the local collapse of the fibers, promotes the rapid drying and stiffening of the fiber support skeleton, and is beneficial to maintaining the integrity of the internal space structure and the outer surface of the material; in the second step, the oven temperature is controlled to be 120-130 ℃, and the drying time is 30-50 min; this process is a microporous process, which promotes the complete decomposition of the remaining sodium bicarbonate in the fiber material to release gas, accelerates the internal drying of the fiber material, and forms uniform and small micropores in the internal part, avoiding the decomposition of the sodium bicarbonate at too high a temperature and too fast, which causes extrusion disturbance to the original fiber structure; in the third step, the oven temperature is controlled to be 150-170 ℃, and the drying time is 2-3 h; this stage is the later stage of the microporous paper-based material forming, and is to completely dry the paper pulp mixture into a paper pulp material product containing micropores in the internal part.

[0023] The application further provides a paper-based material with uniform internal micropore distribution prepared by the preparation method.

[0024] Preferably, the paper-based material comprises, by weight fraction, 3-10 parts of paper pulp, 0.1-2 parts of pore releasing agent, 0.5-3 parts of sodium dodecyl sulfate, and 85-96.4 parts of tap water.

[0025] Preferably, the paper pulp is a mixture of waste paper pulp and conifer pulp board; the weight ratio of the waste paper pulp to the conifer pulp board is 2:8-4:6.

[0026] Preferably, the pore releasing agent is a mixed solution with a mass concentration of 10%-15%.

[0027] Preferably, the tap water is clean and free of small particles, and has a pH of 7.5-8.0.

[0028] The application provides a paper-based material with uniform internal micropore distribution and a preparation method thereof, and the paper-based material has uniform internal micropore distribution and good elasticity, and is a green and environment-friendly microporous paper-based material which is renewable, degradable and recyclable. The prepared paper-based material with uniform internal micropore distribution has finer pores and higher energy dissipation characteristics compared with traditional porous paper-based materials. The microporous paper-based material takes long fibers as a skeleton, and short fibers are filled in the skeleton to form a three-dimensional microporous paper-based material with long and short fibers interwoven, and can be used in fields such as building, sound absorption and packaging.

[0029] Compared with the prior art, the application has the beneficial effects that:

[0030] 1. The microporous paper-based material prepared by using the pore-releasing agent and the micropore drying treatment process realizes the integrity of the paper-based product form and the uniform distribution of pores, avoids defects such as cavities and straight-through holes, and ensures uniform distribution of fibers. The material takes paper pulp as a raw material and does not add plastic additives, embodies the green and environment-friendly production concept, and meets the sustainable development trend.

[0031] 2. The preparation process is simple, controllable and easy to realize automation, and improves the production efficiency and product quality stability. As a new paper-based plastic material, it not only reduces the dependence on traditional plastics, but also has a wide application prospect in the fields of building, packaging, sound absorption and the like, and has great potential to replace traditional materials. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 A flow chart of the preparation method of the microporous paper-based material provided by the application is shown in the figure.

[0033] Figure 2 A cross-sectional photo of the paper-based material with uniform internal micropore distribution prepared in Example 1. DETAILED DESCRIPTION

[0034] In order to make the application more obvious and easy to understand, the preferred embodiments are described in detail below with reference to the accompanying drawings.

[0035] Example 1

[0036] A paper-based material with uniform internal micropore distribution comprises the following components by weight ratio: paper pulp 4 parts, pore-releasing agent 1 part, sodium dodecyl sulfate 1 part, and tap water 94 parts.

[0037] The preparation method of the paper-based material with uniform internal micropore distribution comprises the following steps:

[0038] (1) Pulping: waste paper and conifer pulp board are mixed and put into a pulper at a weight ratio of 3:7, tap water is added, and the paper pulp is broken by a machine, the pulper rotates at a speed of 2650 r / min, and the pulping time is controlled to be 25 min;

[0039] (2) Refining: the paper pulp obtained in step (1) is refined, the rotating speed of the refiner is 2580 r / min, and the circulation refining time is 20 min;

[0040] (3) Preparation of pore-releasing agent solution, the preparation method of the pore-releasing agent solution is as follows: glycerol, sodium bicarbonate and deionized water are mixed to prepare a solution with a mass fraction of 12%; wherein the addition amount of glycerol is controlled to be 7%, and the addition amount of sodium bicarbonate is controlled to be 5%;

[0041] (4) Blending: the slurry prepared in step (2) is put into a stirrer, the mass concentration of the slurry in the stirrer is controlled to be 4.5%, tap water accounts for 93.5% by weight, the pore-releasing agent prepared in step (3) is added, and the addition amount is 1.0%; the rotating speed of the stirrer is controlled to be 570 r / min, and the stirring and mixing time is 10 min; then, soaking is performed for 50 min, so that the pore-releasing agent is fully combined with the paper pulp fibers;

[0042] (5) Swelling treatment: the mixed slurry prepared in step (4) is stirred again uniformly, the rotating speed of the stirrer is controlled to be 245 r / min, and the stirring and mixing time is 12 min; the rotating speed of the stirrer is reduced to 155 r / min, and 1.0% of sodium dodecyl sulfate is added into the stirring barrel; after the addition is completed, mixing is performed for 2 min; then, the rotating speed of the stirring is controlled to be 500 r / min; and stirring is performed for 4 min to make the mixed slurry swell, and the swelling treatment of the paper pulp is completed.

[0043] (6) Microporous drying treatment: the swollen paper pulp prepared in step (5) is immediately loaded into a mold, and is placed in an oven for microporous drying process treatment as follows. The first step in the microporous drying process is to control the oven temperature to be 105℃, and the drying time is 35 min; the second step in the microporous drying process is to control the oven temperature to be 120℃, and the drying time is 40 min; the third step in the microporous drying process is to control the oven temperature to be 155℃, and the drying time is 3h; and the multi-microporous paper-based product is obtained.

[0044] Example 2

[0045] A paper-based material with uniform internal micropore distribution, comprising the following components by weight ratio: paper pulp 4.5 parts, pore-releasing agent 1 part, sodium dodecyl sulfate 1.5 parts, and tap water 93 parts.

[0046] The preparation method of the paper-based material with uniform internal micropore distribution, comprising the following steps:

[0047] (1) Pulping: waste paper and coniferous wood pulp board are mixed according to a weight ratio of 3:7, and tap water is added, and the paper pulp is broken by a machine, the rotating speed of the pulper is 2650 r / min, and the pulping time is controlled to be 25 min;

[0048] (2) Refining: the paper pulp obtained in step (1) is refined, the rotating speed of the refiner is 2580 r / min, and the refining time is 20 min;

[0049] (3) Preparation of pore-releasing agent solution, the preparation method of the pore-releasing agent solution is as follows: glycerol, sodium bicarbonate and deionized water are mixed to prepare a solution with a mass fraction of 13%; wherein the addition amount of glycerol is controlled to be 7%, and the addition amount of sodium bicarbonate is controlled to be 6%;

[0050] (4) Blending: the slurry prepared in step (2) is put into a stirrer, the mass concentration of the slurry in the stirrer is controlled to be 4.5%, tap water accounts for 93 wt%, the pore-releasing agent prepared in step (3) is added, and the addition amount is 1.0%, the rotating speed of the stirrer is controlled to be 600 r / min, and the stirring and mixing time is 10 min; then, soaking is performed for 30 min;

[0051] (5) Swelling treatment: the mixed slurry prepared in step (4) is stirred again uniformly, the rotating speed of the stirrer is controlled to be 245 r / min, the stirring and mixing time is 12 min; the rotating speed of the stirrer is reduced to 155 r / min, and 1.5% of sodium dodecyl sulfate is added into the stirring barrel; after the addition is completed, mixing is performed for 2 min; then, the rotating speed of the stirrer is controlled to be 500 r / min; the stirring time is 5 min to make the mixed slurry swell, and the swelling treatment of the paper pulp is completed.

[0052] (6) Microporous drying treatment: the swollen paper pulp prepared in step (5) is immediately loaded into a mold, and is placed in an oven for microporous drying treatment according to the following microporous drying process. In the first step of the microporous drying process, the temperature of the oven is controlled to be 105℃, and the drying time is 35 min; in the second step of the microporous drying process, the temperature of the oven is controlled to be 120℃, and the drying time is 40 min; in the third step of the microporous drying process, the temperature of the oven is controlled to be 155℃, and the drying time is 3 h; and the multi-microporous paper-based product is obtained.

[0053] Example 3

[0054] A paper-based material with uniform internal micropore distribution, comprising the following components by weight ratio: paper pulp 3 parts, pore-releasing agent 1 part, sodium dodecyl sulfate 1.5 parts, and tap water 94.5 parts.

[0055] The preparation method of the paper-based material with uniform internal micropore distribution, comprising the following steps:

[0056] (1) Pulping: waste paper and coniferous wood pulp board are mixed according to a weight ratio of 2:8, and tap water is added, and the paper pulp is broken by a machine, the rotating speed of the pulper is 2650 r / min, and the pulping time is controlled to be 25 min;

[0057] (2) Refining: the paper pulp obtained in step (1) is refined, the rotating speed of the refiner is 2550 r / min, and the refining is performed for 20 min in circulation;

[0058] (3) Preparation of the pore-releasing agent solution, the pore-releasing agent solution is prepared by mixing glycerol, sodium bicarbonate and deionized water to obtain a solution with a mass fraction of 12%; wherein the amount of glycerol added is controlled to be 6%, and the amount of sodium bicarbonate added is controlled to be 6%;

[0059] (4) Blending: the slurry prepared in step (2) is placed in a stirrer, the mass concentration of the slurry in the stirrer is controlled to be 3%, tap water accounts for 94.5% by weight, the pore-releasing agent prepared in step (3) is added, the addition amount is 1.0%, the rotating speed of the stirrer is controlled to be 700 r / min, and the stirring and mixing are performed for 10 min; then, soaking is performed for 40 min;

[0060] (5) Swelling treatment: the mixed slurry prepared in step (4) is stirred again uniformly, the rotating speed of the stirrer is controlled to be 245 r / min, the stirring and mixing are performed for 12 min; the rotating speed of the stirrer is reduced to 155 r / min, 1.5% of sodium dodecyl sulfate by mass is added into the stirring barrel; after the addition is completed, mixing is performed for 2 min; then, the rotating speed of the stirrer is controlled to be 500 r / min; the stirring is performed for 5 min to make the mixed slurry swell in volume, and the swelling treatment of the paper pulp is completed.

[0061] (6) Microporous drying treatment: the swollen paper pulp prepared in step (5) is immediately loaded into a mold, and is placed in an oven for microporous drying treatment according to the following microporous drying process. In the first step of the microporous drying process, the temperature of the oven is controlled to be 98℃, and the drying time is 40 min; in the second step of the microporous drying process, the temperature of the oven is controlled to be 120℃, and the drying time is 40 min; in the third step of the microporous drying process, the temperature of the oven is controlled to be 165℃, and the drying time is 2.5 h; the multi-microporous paper-based product is obtained.

[0062] The multi-microporous paper-based products obtained in Examples 1-3 are subjected to physical and chemical property tests, and the test results of various physical and chemical indexes are shown in Table 1, wherein the surface flatness is the comparison of the size of the product (length, width and height) with the size of the standard mold.

[0063] Table 1

[0064]

[0065]

Claims

1. A method of making a paper-based material having a uniform internal pore distribution, characterized by, The method comprises the following steps: Step 1), pulping: the paper pulp is put into a pulper, and tap water is added, and the paper pulp is broken by a machine; Step 2), grinding: the paper pulp obtained in step 1) is ground to obtain pulp; the paper pulp is a mixture of waste paper pulp and coniferous wood pulp board; the weight ratio of the waste paper pulp to the coniferous wood pulp board is 2:8-4:6; Step 3), preparation of pore releasing agent solution: glycerol, sodium bicarbonate and deionized water are mixed to prepare a pore releasing agent solution; the mass concentration of the pore releasing agent solution is 10%-15%; wherein the addition amount of glycerol is controlled to be 5%-10%, and the addition amount of sodium bicarbonate is controlled to be 5%-10%; Step 4), blending: the pulp prepared in step 2) is put into a stirrer, the pore releasing agent solution prepared in step 3) is added first, and stirring and mixing are performed; then soaking is performed to make the pore releasing agent fully combined with the paper pulp fibers; Step 5), swelling treatment: the mixed slurry prepared in step 4) is stirred again uniformly, the stirring speed of the stirrer is controlled to be 200-300 r / min, and stirring and mixing are performed for 10-20 min; the stirring speed of the stirrer is reduced to 150-200 r / min, and after sodium dodecyl sulfate is added, mixing is performed for 2 min; then the stirring speed is controlled to be 400-560 r / min; stirring is performed for 3-6 min to make the mixed slurry volume swell, and the paper pulp swelling treatment is completed; the sodium dodecyl sulfate is a solution with a mass concentration of 1%-5%; Step 6), microporous drying treatment: the swollen paper pulp prepared in step 5) is immediately loaded into a mold, and is placed in an oven for microporous drying process treatment to obtain a multi-microporous paper-based material.

2. The production method according to claim 1, wherein In step 1), the tap water is clean and free of fine particles, and the pH is 7.5-8.

0.

3. The production method according to claim 1, wherein In step 1), the mechanical crushing uses a pulper, the rotating speed of the pulper is 2000-3000 r / min, and the time is 20-40 min.

4. The production method according to claim 1, wherein In step 2), the grinding uses a grinding machine, the rotating speed of the grinding machine is 2500-2800 r / min, and the circulating grinding time is 20 min.

5. The production method according to claim 1, wherein In step 4), the mass concentration of the pulp in the stirrer is controlled to be 3%-7%, the addition amount of the pore releasing agent solution is 0.5wt%-1.5wt%, the rotating speed of the stirrer is controlled to be 500-700 r / min, and stirring and mixing are performed for 10-15 min; the soaking time is 30-60 min.

6. The method of making a paper-based material having a uniform internal pore distribution according to claim 1, wherein, In step 6), the microporous drying process is as follows: in the first step, the oven temperature is controlled to be 90-110℃, and the drying time is 30-40 min; in the second step, the oven temperature is controlled to be 120-130℃, and the drying time is 30-50 min; in the third step, the oven temperature is controlled to be 150-170℃, and the drying time is 2-3 h.

7. A paper-based material with uniform internal micropore distribution, which is prepared by the preparation method of any one of claims 1-6.

8. The paper-based material of claim 7 having a uniform internal pore distribution, wherein, The paper-based material comprises paper pulp 3-10 parts, pore releasing agent 0.1-2 parts, sodium dodecyl sulfate 0.5-3 parts, and tap water 85-96.4 parts by weight.

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