Multilayer filter paper and preparation method thereof

Abstract

The invention relates to the technical field of filter paper and discloses multilayer filter paper and a preparation method thereof.The multilayer filter paper is prepared from 60%-80% of cellulose fiber, 5%-15% of nano cellulose, 1%-5% of functional surface modifier, 5%-10% of natural fiber enhancer, 1%-5% of functional filler, 3%-8% of bio-based polymer and 0.5%-3% of other additives, the functional surface modifier is optionally selected from two to three of a surfactant, a polymer modifier, an antibacterial agent, an adsorbent, an antistatic agent and a waterproof agent, and the natural fiber enhancer is optionally selected from two of bamboo fiber, coarse paper fiber, palm fiber and linen fiber. The functional filler is optionally selected from two of nanoparticles, carbon nanotubes, activated carbon, silica gel particles and molecular sieves, and the bio-based polymer is optionally selected from two of rubber resin, xylose gum and polylactic acid. By accurately controlling material pretreatment, wet strength, adhesiveness and hot-pressing drying parameters in the manufacturing process, reliability, efficiency and consistency of filter paper products are ensured, and performance standards are met.

Description

Technical Field

[0001] The invention relates to the technical field of filter paper, in particular to a multi-layer filter paper and a preparation method thereof. Background Art

[0002] With the development of industry, more and more filtering equipment is used in many industries and daily life, such as air filters, car engine filters, coffee filter papers, and water treatment equipment. In order to achieve the filtering effect, these devices will use multiple layers of filter paper as components.

[0003] Traditional filter paper production relies too much on limited resources, such as wood pulp, and uses chemically synthesized adhesives and fillers. These materials have a negative impact on the environment, leading to increased deforestation, land degradation, water resource depletion, and air and water pollution. At the same time, traditional filter paper has limitations in strength, stability and service life, especially under high-intensity and long-term use conditions, resulting in a shorter product life and more frequent replacement, which increases usage costs and waste of resources. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a multi-layer filter paper and a preparation method thereof, which solves the problem.

[0005] To achieve the above objectives, the present invention is implemented through the following technical scheme: a multi-layer filter paper and a preparation method thereof, comprising the following proportions: 60%-80% cellulose fiber, 5%-15% nanocellulose, 1%-5% functional surface modifier, 5%-10% natural fiber reinforcement, 1%-5% functional filler, 3%-8% bio-based polymer and 0.5%-3% other additives.

[0006] Preferably, the functional surface modifier is two or three of a surfactant, a polymer modifier, an antibacterial agent, an adsorbent, an antistatic agent and a water-proofing agent.

[0007] Preferably, the natural fiber reinforcement is any one of bamboo fiber, straw paper fiber, palm fiber and flax fiber.

[0008] Preferably, the functional filler is any two of nanoparticles, carbon nanotubes, activated carbon, silica gel particles and molecular sieves.

[0009] Preferably, the bio-based polymer is selected from two of rubber gum, xylan gum and polylactic acid.

[0010] A multi-layer filter paper comprises the following steps:

[0011] S1. Pretreatment of cellulose-based materials: Pretreatment of selected natural fibers, such as cleaning, beating, and bleaching, to ensure the purity and appropriate physical properties of the fibers;

[0012] S2. Mixing and uniform dispersion: Place the pretreated cellulose-based material into a mixing container, gradually add the functional filler and bio-based polymer, and ensure uniform dispersion of the material by stirring or mixing;

[0013] S3. Adjust wet strength and adhesion: Adjust the amount of water added and the mixing time as needed to control the wet strength and the final adhesion properties of the filter paper;

[0014] S4. Add other additives gradually: add preservatives, antioxidants, dyes or fluorescent whitening agents, fragrances or deodorants, and lubricants in sequence, ensuring that each additive is evenly dispersed and fully mixed;

[0015] S5, wet forming: the mixture is uniformly wet formed on a filter paper forming machine to form a preliminary filter paper structure through extrusion and drying;

[0016] S6, hot pressing and drying: hot pressing and drying the initially formed filter paper structure to ensure the strength and stability of the filter paper;

[0017] S7, Inspection and Packaging: The finished filter paper is inspected to ensure that it meets the predetermined performance requirements and quality standards, and then packaged and stored.

[0018] Preferably, the cellulose-based material pretreatment comprises the following steps:

[0019] S1-1. Select appropriate natural fibers: Select appropriate natural fibers as the base material according to the final application and performance requirements of the filter paper;

[0020] S1-2, Cleaning: Clean the selected natural fibers to remove surface impurities and dirt by soaking, rinsing or mechanical washing;

[0021] S1-3, beating: breaking the fiber bundles by mechanical shearing and friction to make them into fiber bundles between cellulose cells;

[0022] S1-4. Bleaching: If white or light-colored filter paper is required, bleaching treatment can be performed to remove pigments and non-cellulose components in the pulp. Commonly used bleaching agents include chlorine, oxidants (such as hydrogen peroxide) and chlorine dioxide to improve the appearance and purity of the filter paper.

[0023] S1-5. Adjust the humidity of the fiber material: adjust the humidity by adding an appropriate amount of water or controlling the storage time of the fiber material. Appropriate humidity can improve the plasticity and processability of the fiber material.

[0024] S1-6. Quality control: Check the appearance and structure of the fibers, test the purity and moisture content of the pulp, and evaluate the effectiveness of the bleaching treatment.

[0025] Preferably, the proportion of water in adjusting the wet strength and adhesion is 5%-20%, and the mixing time is 5 minutes to 20 minutes.

[0026] Preferably, the drying temperature in the hot pressing and drying is between 80° C. and 120° C., and the time is between 10 minutes and 30 minutes.

[0027] The present invention provides a multi-layer filter paper and a preparation method thereof, which has the following beneficial effects:

[0028] 1. The present invention can prepare filter paper products that meet environmental protection standards by selecting appropriate natural fibers and bio-based polymers, and adding environmentally friendly functional fillers and fillers. These materials not only reduce dependence on limited resources, but also reduce the negative impact of filter paper on the environment, such as good degradation performance, reducing energy consumption and waste emissions in the production process.

[0029] 2. The present invention can improve the strength, stability and service life of filter paper products by precisely controlling the pretreatment process of cellulose-based materials, the adjustment of wet strength and adhesion, and the temperature and time settings of hot pressing and drying. These measures not only ensure the reliability and efficiency of the filter paper during use, but also ensure the consistency of the product and compliance with performance standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example:

[0033] Please see attached Figure 1 The embodiment of the present invention provides a multilayer filter paper and a preparation method thereof, comprising the following proportions: 60%-80% cellulose fiber, 5%-15% nanocellulose, 1%-5% functional surface modifier, 5%-10% natural fiber reinforcement, 1%-5% functional filler, 3%-8% bio-based polymer and 0.5%-3% other additives.

[0034] The functional surface modifier is selected from two to three of surfactants, polymer modifiers, antibacterial agents, adsorbents, antistatic agents and waterproofing agents. The natural fiber reinforcement is selected from two of bamboo fiber, straw paper fiber, palm fiber and flax fiber. The functional filler is selected from two of nanoparticles, carbon nanotubes, activated carbon, silica gel particles and molecular sieves. The bio-based polymer is selected from two of rubber gum, xylan gum and polylactic acid. Other additives are selected from two to three of preservatives, antioxidants, dyes, fluorescent whitening agents, deodorants and lubricants.

[0035] A method for preparing a multilayer filter paper comprises the following steps:

[0036] S1. Pretreatment of cellulose-based materials: Pretreatment of selected natural fibers, such as cleaning, beating, and bleaching, to ensure the purity and appropriate physical properties of the fibers;

[0037] S1-1. Select appropriate natural fibers: Select appropriate natural fibers as the base material according to the final application and performance requirements of the filter paper;

[0038] S1-2, Cleaning: Clean the selected natural fibers to remove surface impurities and dirt by soaking, rinsing or mechanical washing;

[0039] S1-3, beating: breaking the fiber bundles by mechanical shearing and friction to make them into fiber bundles between cellulose cells;

[0040] S1-4, bleaching: If you need to get white or light-colored filter paper, you can perform bleaching to remove pigments and non-cellulose components in the pulp. Commonly used bleaching agents include chlorine, oxidants (such as hydrogen peroxide) and chlorine dioxide to improve the appearance and purity of the filter paper;

[0041] S1-5. Adjust the humidity of the fiber material: adjust the humidity by adding an appropriate amount of water or controlling the storage time of the fiber material. Appropriate humidity can improve the plasticity and processability of the fiber material.

[0042] S1-6, Quality Control: Check the appearance and structure of the fiber, test the purity and moisture content of the pulp, and evaluate the effectiveness of the bleaching treatment;

[0043] S2. Mixing and uniform dispersion: Place the pretreated cellulose-based material into a mixing container, gradually add the functional filler and bio-based polymer, and ensure uniform dispersion of the material by stirring or mixing;

[0044] S3. Adjust wet strength and adhesion: adjust the amount of water added and mixing time as needed to control the wet strength and the final adhesion performance of the filter paper; adjust the water ratio in the wet strength and adhesion to 5%-20%, and the mixing time to 5 minutes to 20 minutes.

[0045] S4. Add other additives gradually: add preservatives, antioxidants, dyes or fluorescent whitening agents, fragrances or deodorants, and lubricants in sequence, ensuring that each additive is evenly dispersed and fully mixed;

[0046] S5, wet forming: the mixture is uniformly wet formed on a filter paper forming machine to form a preliminary filter paper structure through extrusion and drying;

[0047] S6. Hot pressing and drying: The initially formed filter paper structure is hot pressed and dried to ensure the strength and stability of the filter paper; the drying temperature during hot pressing and drying is between 80℃ and 120℃, and the time is 10 minutes to 30 minutes.

[0048] S7, Inspection and Packaging: The finished filter paper is inspected to ensure that it meets the predetermined performance requirements and quality standards, and then packaged and stored.

[0049] Example 1: Preparation of bamboo fiber environmentally friendly filter paper

[0050] 1. Pretreatment of cellulose-based materials:

[0051] Bamboo fiber was selected as the main cellulose-based material.

[0052] Clean the bamboo fibers to remove impurities and dirt.

[0053] Mechanical beating is performed to break down the bamboo fiber bundles to an appropriate degree.

[0054] 2. Adjust wet strength and adhesion:

[0055] Add about 15% water and gradually mix the bamboo fiber to ensure that the water fully penetrates.

[0056] The mixing time is about 15 minutes, until the fibers are evenly dispersed and the desired wet strength and adhesion are achieved.

[0057] 3. Hot pressing and drying:

[0058] The hot pressing temperature was set at 130°C and the pressure was appropriate to ensure that the bamboo fibers were fully bonded.

[0059] The drying temperature was set at 100 °C and the drying time was about 20 min to ensure that the filter paper was evenly dried.

[0060] Summarize:

[0061] This example shows the specific steps of preparing environmentally friendly filter paper using bamboo fiber. Through appropriate pretreatment of cellulose-based materials, precise adjustment of wet strength and adhesion, and appropriate hot pressing and drying parameter settings, bamboo fiber environmentally friendly filter paper with good strength and stability can be prepared.

[0062] Example 2: Preparation of environmentally friendly filter paper made of straw paper fibers

[0063] 1. Pretreatment of cellulose-based materials:

[0064] Grass paper fibers are selected as the main cellulose-based material and undergo a thorough cleaning and bleaching process to increase purity.

[0065] Chemical pulping is carried out to remove non-cellulose components using appropriate chemicals to obtain fine pulp.

[0066] 2. Adjust wet strength and adhesion:

[0067] Add about 10% water and adjust the mixing time to about 10 minutes to ensure that the straw paper fibers are fully absorbed and evenly dispersed.

[0068] Determine the adhesive addition ratio to optimize bonding performance.

[0069] 3. Hot pressing and drying:

[0070] The hot pressing temperature was set at 120°C and the pressure was moderate to ensure effective bonding of the cellulose-based materials at high temperatures.

[0071] The drying temperature is set at 90°C and the drying time is about 15 minutes to ensure that the straw paper fiber environmentally friendly filter paper is dried evenly.

[0072] Summarize:

[0073] This example shows the process of preparing environmentally friendly filter paper using grass paper fibers. Through thorough pretreatment of cellulose-based materials, precise adjustment of wet strength and adhesion, and appropriate hot pressing and drying conditions, grass paper fiber environmentally friendly filter paper suitable for specific applications can be obtained.

[0074] Example 3: Preparation of mixed fiber environmentally friendly filter paper

[0075] 1. Pretreatment of cellulose-based materials:

[0076] Bamboo fiber and straw paper fiber were selected as mixed cellulose-based materials and subjected to separate cleaning and bleaching processes.

[0077] Mechanical beating and chemical beating are carried out separately, and different cellulose-based materials are mixed according to the proportions.

[0078] 2. Adjust wet strength and adhesion:

[0079] Add appropriate amount of water and adjust the mixing time according to the mixing ratio to ensure that all kinds of fibers are fully mixed and bonded.

[0080] Determine the appropriate binder ratio to ensure good bonding of the various fibers.

[0081] 3. Hot pressing and drying:

[0082] The hot pressing temperature was set at 140°C and the pressure was moderate to ensure effective bonding of the mixed fibers at high temperatures.

[0083] The drying temperature was set at 110°C and the drying time was about 25 minutes to ensure that the mixed fiber environmentally friendly filter paper was fully dried.

[0084] Summarize:

[0085] This example demonstrates the process of preparing environmentally friendly filter paper by mixing bamboo fiber and straw paper fiber. By rationally selecting and pre-treating different cellulose-based materials, accurately adjusting wet strength and adhesion, and effectively controlling hot pressing and drying parameters, a mixed fiber environmentally friendly filter paper with excellent performance and stability can be prepared.

[0086] Cellulose-based material selection and pretreatment:

[0087] Comparative Example 1 (bamboo fiber environmentally friendly filter paper):

[0088] Selection and Processing: Bamboo fiber is selected as the main cellulose-based material and processed by cleaning and mechanical beating.

[0089] Advantages: Bamboo fiber has high strength and durability.

[0090] Applicability: Suitable for filter paper applications requiring high strength and stability.

[0091] Comparative Example 2 (straw fiber environmentally friendly filter paper):

[0092] Selection and processing: Select grass paper fibers, which are thoroughly cleaned and chemically beaten.

[0093] Advantages: Straw paper fibers have good smoothness and plasticity.

[0094] Suitability: Suitable for filter paper applications requiring a smooth surface and soft feel.

[0095] Comparative Example 3 (mixed fiber environmentally friendly filter paper):

[0096] Selection and processing: Bamboo fiber and straw paper fiber are selected for mixing, cleaning and mechanical / chemical beating treatment respectively.

[0097] Advantages: Combines the strength of bamboo fiber and the smoothness of straw paper fiber.

[0098] Applicability: Suitable for filter paper applications that require both strength and surface smoothness.

[0099] Common points: All embodiments focus on selecting the purity and adaptability of cellulose-based materials, and ensuring proper dispersion of fibers and uniformity of pulp through pulping.

[0100] Adjusting wet strength and adhesion:

[0101] Comparative Example 1:

[0102] Water addition ratio: about 15%, mixing time about 15 minutes.

[0103] Adhesive Use: Ensures that bamboo fibers are fully bonded, improving wet strength and overall stability.

[0104] Comparative Example 2:

[0105] Water addition ratio: about 10%, mixing time about 10 minutes.

[0106] Adhesive usage: Optimize the addition ratio of adhesive to ensure good bonding and softness of straw paper fibers.

[0107] Comparative Example 3:

[0108] Water addition ratio: Add water in appropriate amount according to the mixing ratio and adjust the mixing time to ensure that various fibers are fully mixed.

[0109] Adhesive Use: Balance the bonding properties of bamboo fiber and straw paper fiber to ensure overall product quality and performance.

[0110] What they have in common: Each embodiment adjusts the amount of water and binder used based on fiber properties and application requirements to ensure paper strength, stability and quality.

[0111] Hot pressing and drying parameter settings:

[0112] Comparative Example 1:

[0113] Hot pressing temperature: 130℃

[0114] Drying temperature: 100°C, drying time about 20 minutes.

[0115] Comparative Example 2:

[0116] Hot pressing temperature: 120℃

[0117] Drying temperature: 90℃, drying time about 15 minutes.

[0118] Comparative Example 3:

[0119] Hot pressing temperature: 140℃

[0120] Drying temperature: 110℃, drying time about 25 minutes.

[0121] Common points: Through high temperature hot pressing and moderate drying, the paper is fully bonded and dried, thereby improving the strength, flatness and service life of the filter paper.

[0122] Table 1:

[0123]

[0124] According to the above table, Example 1 selects bamboo fiber and undergoes mechanical pulping; Example 2 selects straw paper fiber and undergoes chemical pulping; Example 3 uses a mixture of bamboo fiber and straw paper fiber and undergoes mechanical or chemical pulping, respectively. They differ in adjusting wet strength, adhesion, and hot pressing and drying parameters to meet different strength, smoothness, and application requirements. Each example focuses on the selection and processing of cellulose-based materials, and ensures the quality and performance of the final environmentally friendly filter paper through precisely adjusted process flows.

[0125] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-layer filter paper, characterized in that: It consists of the following proportions: cellulose fiber 60% - 80%, nanocellulose 5% - 15%, functional surface modifier 1% - 5%, natural fiber reinforcement 5% - 10%, functional filler 1% - 5%, bio-based polymer 3% - 8% and other additives 0.5% - 3%.

2. A multi-layer filter paper according to claim 1, characterized in that: The functional surface modifier is selected from two or three of a surfactant, a polymer modifier, an antibacterial agent, an adsorbent, an antistatic agent and a water-proofing agent.

3. A multi-layer filter paper according to claim 1, characterized in that: The natural fiber reinforcing agent is selected from two kinds of bamboo fiber, straw paper fiber, palm fiber and flax fiber.

4. The multi-layer filter paper according to claim 1, characterized in that: The functional filler can be any two of nanoparticles, carbon nanotubes, activated carbon, silica gel particles and molecular sieves.

5. The multi-layer filter paper according to claim 1, characterized in that: The bio-based polymers are selected from two of rubber gum, xylan gum and polylactic acid.

6. The multi-layer filter paper according to claim 1, characterized in that: The other additives are optionally two to three selected from the group consisting of preservatives, antioxidants, dyes, fluorescent whitening agents, deodorants and lubricants.

7. A method for preparing a multilayer filter paper, according to the multilayer filter paper according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Pretreatment of cellulose-based materials: Pretreatment of selected natural fibers, such as cleaning, beating, and bleaching, to ensure the purity and appropriate physical properties of the fibers; S2. Mixing and uniform dispersion: Place the pretreated cellulose-based material into a mixing container, gradually add the functional filler and bio-based polymer, and ensure uniform dispersion of the material by stirring or mixing; S3. Adjust wet strength and adhesion: Adjust the amount of water added and the mixing time as needed to control the wet strength and the final adhesion properties of the filter paper; S4. Add other additives gradually: add preservatives, antioxidants, dyes or fluorescent whitening agents, fragrances or deodorants, and lubricants in sequence, ensuring that each additive is evenly dispersed and fully mixed; S5, wet forming: the mixture is uniformly wet formed on a filter paper forming machine to form a preliminary filter paper structure through extrusion and drying; S6, hot pressing and drying: hot pressing and drying the initially formed filter paper structure to ensure the strength and stability of the filter paper; S7, Inspection and Packaging: The finished filter paper is inspected to ensure that it meets the predetermined performance requirements and quality standards, and then packaged and stored.

8. The multi-layer filter paper and the preparation method thereof according to claim 1, characterized in that: The cellulose-based material pretreatment comprises the following steps: S1-1. Select appropriate natural fibers: Select appropriate natural fibers as the base material according to the final application and performance requirements of the filter paper; S1-2, Cleaning: Clean the selected natural fibers to remove surface impurities and dirt by soaking, rinsing or mechanical washing; S1-3, beating: breaking the fiber bundles by mechanical shearing and friction to make them into fiber bundles between cellulose cells; S1-4. Bleaching: If white or light-colored filter paper is required, bleaching treatment can be performed to remove pigments and non-cellulose components in the pulp. Commonly used bleaching agents include chlorine, oxidants (such as hydrogen peroxide) and chlorine dioxide to improve the appearance and purity of the filter paper. S1-5. Adjust the humidity of the fiber material: adjust the humidity by adding an appropriate amount of water or controlling the storage time of the fiber material. Appropriate humidity can improve the plasticity and processability of the fiber material. S1-6. Quality control: Check the appearance and structure of the fibers, test the purity and moisture content of the pulp, and evaluate the effectiveness of the bleaching treatment.

9. The multi-layer filter paper and the preparation method thereof according to claim 1, characterized in that: The proportion of water in adjusting the wet strength and adhesion is 5%-20%, and the mixing time is 5 minutes to 20 minutes.

10. The multi-layer filter paper and the preparation method thereof according to claim 1, characterized in that: The drying temperature in the hot pressing and drying is between 80° C. and 120° C., and the drying time is between 10 minutes and 30 minutes.

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