CN114703699A - Preparation method and application of fibrillated fibers - Google Patents
Preparation method and application of fibrillated fibers Download PDFInfo
- Publication number
- CN114703699A CN114703699A CN202210386135.0A CN202210386135A CN114703699A CN 114703699 A CN114703699 A CN 114703699A CN 202210386135 A CN202210386135 A CN 202210386135A CN 114703699 A CN114703699 A CN 114703699A
- Authority
- CN
- China
- Prior art keywords
- pulp
- screening
- fibrillated
- fiber
- refining
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000835 fiber Substances 0.000 title claims abstract description 121
- 238000002360 preparation method Methods 0.000 title abstract description 8
- 238000012216 screening Methods 0.000 claims abstract description 61
- 238000007670 refining Methods 0.000 claims abstract description 40
- 238000004537 pulping Methods 0.000 claims abstract description 37
- 238000007865 diluting Methods 0.000 claims abstract description 17
- 238000002156 mixing Methods 0.000 claims abstract description 12
- 238000000034 method Methods 0.000 claims description 21
- 229920000433 Lyocell Polymers 0.000 claims description 11
- 239000003990 capacitor Substances 0.000 claims description 10
- 238000010009 beating Methods 0.000 claims description 7
- 238000007873 sieving Methods 0.000 claims description 3
- -1 poly-p-phenylene benzoxazole Chemical compound 0.000 claims description 2
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 2
- 125000001140 1,4-phenylene group Chemical group [H]C1=C([H])C([*:2])=C([H])C([H])=C1[*:1] 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 claims 1
- 239000002002 slurry Substances 0.000 description 33
- 238000000227 grinding Methods 0.000 description 22
- 210000001724 microfibril Anatomy 0.000 description 11
- 239000012528 membrane Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 8
- 230000008569 process Effects 0.000 description 7
- 238000001035 drying Methods 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- 239000011148 porous material Substances 0.000 description 4
- 238000001914 filtration Methods 0.000 description 3
- 238000011056 performance test Methods 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000005303 weighing Methods 0.000 description 2
- WRDNCFQZLUCIRH-UHFFFAOYSA-N 4-(7-azabicyclo[2.2.1]hepta-1,3,5-triene-7-carbonyl)benzamide Chemical compound C1=CC(C(=O)N)=CC=C1C(=O)N1C2=CC=C1C=C2 WRDNCFQZLUCIRH-UHFFFAOYSA-N 0.000 description 1
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 206010061592 cardiac fibrillation Diseases 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000012792 core layer Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 230000002600 fibrillogenic effect Effects 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 238000001453 impedance spectrum Methods 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21D—TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
- D21D5/00—Purification of the pulp suspension by mechanical means; Apparatus therefor
- D21D5/02—Straining or screening the pulp
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/02—Synthetic cellulose fibres
- D21H13/08—Synthetic cellulose fibres from regenerated cellulose
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/12—Organic non-cellulose fibres from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H13/14—Polyalkenes, e.g. polystyrene polyethylene
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/20—Organic non-cellulose fibres from macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/20—Organic non-cellulose fibres from macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D21H13/26—Polyamides; Polyimides
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H15/00—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution
- D21H15/02—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution characterised by configuration
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
- H01G9/004—Details
- H01G9/02—Diaphragms; Separators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/44—Fibrous material
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/13—Energy storage using capacitors
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Mechanical Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Paper (AREA)
Abstract
The invention provides a preparation method of fibrillated fibers, which specifically comprises the following steps: s1, controlling the concentration of the chopped fibers to be 1-30%, and performing pulping treatment by using a first group of pulping equipment to obtain pulp 1 with the pulping degree of 40-65 DEG SR; s2, diluting the concentration of the pulp 1 to 0.01-0.05% for screening treatment, screening by a group of screening devices, mixing the pulp intercepted by the screens of the group of screening devices to obtain pulp 2, and taking the pulp passing through the screen of the last screening device as fibrillated fiber; s3, diluting the pulp 2 to the concentration of 1-30%, and refining the pulp by a second group of refining equipment to 70-95 DEG SR to obtain pulp 3; s4, mixing the pulp 3 and the pulp 1 to form a closed sieving-refining circulating system, and repeating the steps S1-S4. The primary fibrillated fiber is separated out through screening treatment, and the secondary refining equipment grinds the primary fibrillated fiber with diameter greater than 2.5 microns.
Description
Technical Field
The invention relates to the technical field of fiber pulping, in particular to a preparation method and application of fibrillated fibers.
Background
The development of batteries and supercapacitors is directed towards high energy density, while the development of electrolytic and solid state capacitors is directed towards miniaturization. Because the diaphragm is an inactive substance in the battery and the capacitor, but the capacity, the service life and the safety performance of the battery and the capacitor are affected, on the premise of meeting the isolation effect of the diaphragm, reducing the thickness of the diaphragm and ensuring the thickness uniformity become one of important means for improving the performance of the battery and the capacitor. For the fiber interweaving diaphragm, the diameter of the fibers and the interweaving layer number determine the thickness of the diaphragm, the isolation performance of the diaphragm can be guaranteed only by the sufficient interweaving layer number of the fibers, and therefore, the reduction of the diameter of the fibers is very important for controlling the thickness of the diaphragm. Fibrillated fibers having diameters in the range of tens of nanometers to tens of micrometers contain a large number of hundreds of nanometers of macrofibrils, which reduce membrane thickness and pore size, and are preferred fiber materials for battery and capacitor membranes. The fibrillated fibers have a large diameter distribution and are non-uniform in size. This polydispersity of fibrillated fibers is a result of the fact that fibrils are continuously stripped from the main fibers during beating. Fibrillated fibers can be considered to consist of trunk fibers and already stripped fibrils. The fibrils include macrofibrils and microfibrils. The diameter of the trunk fiber is several micrometers to tens of micrometers, so that the thickness of the diaphragm is increased; the diameter of the microfibril is tens of nanometers, pores of the diaphragm are easily blocked under the action of capillary force in the drying process, and the ionic resistance of the diaphragm is increased. Thus, macrofibrils having a diameter of several hundred nanometers are preferred fibers for reducing the thickness of the separator while having a lower ionic resistance.
Patent No. CN101381898B proposes pretreatment of chopped fibers with a pretreatment agent, followed by refining with a refining apparatus to obtain fibrillated fibers, which can be used for battery separators. Patent No. CN109267415A proposes that a nonmetal double-disc grinder beater is used for beating tencel fibers, so that fiber cutting can be reduced, and the strength of the diaphragm paper of the super capacitor is improved. Patent No. CN104518188A proposes that fibrillatable solvent-spun cellulose fibers are ground by a grinding apparatus such as a disc grinder, and then mixed with polyester fibers for lithium ion battery separators. The above described refining process all results in fibrillated fibres, which however comprise trunk fibres, macrofibrils and microfibrils. Larger trunk fiber diameters increase the membrane thickness. The method of long-time low-intensity refining is adopted to continuously strip fibrils from trunk fibers, the method only can reduce the proportion of the trunk fibers, the trunk fibers with the diameter of more than ten microns still exist in the fibrillated fibers, and the local area with excessive thickness is not allowed for the diaphragm. And as the refining time increases, the fibril fraction increases and more refining energy is consumed by the macrofibrils and microfibrils, which increases the microfibril fraction and increases the ionic resistance of the diaphragm.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a preparation method and application of fibrillated fibers, which can reduce the maximum diameter of the fibers and simultaneously have lower proportion of microfibril.
In order to realize the technical scheme, the invention provides a fibrillated fiber preparation method, which specifically comprises the following steps:
s1, controlling the concentration of the chopped fibers to be 1-30%, and performing pulping treatment by using a first group of pulping equipment to obtain pulp 1 with the beating degree of 40-65 DEG SR;
s2, diluting the concentration of the pulp 1 to 0.01-0.05% for screening treatment, screening by a group of screening devices, mixing the pulp intercepted by the screens of the group of screening devices to obtain pulp 2, and taking the pulp passing through the screen of the last screening device as fibrillated fiber;
s3, diluting the pulp 2 to 1-30% of concentration, and pulping by a second group of pulping equipment to 70-95 DEG SR to obtain pulp 3;
and S4, mixing the pulp 3 with the pulp 1 to form a closed sieving-refining circulating system, and repeating the steps S1-S4 until the pulp completely passes through the screen of the last sieving device.
Preferably, the chopped fiber is one or more of tencel fiber, poly-p-phenylene terephthalamide fiber, polyacrylonitrile fiber or poly-p-phenylene benzoxazole fiber.
Preferably, the refining apparatus is one or more of a disc refiner, a conical refiner, a cylindrical refiner or a trough refiner.
Preferably, the screening device is formed by connecting a plurality of vibrating screens or filters in series, wherein the mesh number of the vibrating screens is increased sequentially.
Preferably, the screen mesh number of the screening device is 300 meshes, the screen mesh number of the first screening device is 100 meshes, the screen mesh number of the last screening device is 300 meshes, and the screen mesh number of the former screening device is smaller than that of the latter screening device.
Preferably, the maximum diameter of the fibrillated fibres obtained after screening by the last vibrating screen mesh is less than 2.5 μm.
The invention also provides application of the fibrillated fiber, and the fibrillated fiber prepared by the method is applied to papermaking of battery separators or capacitor separators.
The preparation method and the device for the fibrillated fiber provided by the invention have the beneficial effects that: the preparation method of the original fibrillated fiber can lead the maximum diameter of the fibrillated fiber to be less than 2.5 mu m through screening treatment, and can separate out the main fiber with the diameter more than 2.5 mu m through screening treatment, and the second group of refining equipment only grinds the main fiber with the diameter more than 2.5 mu m, thereby reducing the proportion of microfibril.
Drawings
FIG. 1 is a schematic process flow diagram of the present invention.
Fig. 2 is an electron microscope scan of fibrillated fibers obtained in example 2 and comparative example 2 of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by a person skilled in the art without making any inventive step are within the scope of the present invention.
Example 1
A fibrillated fiber prepared by the steps of:
(1) controlling the tencel chopped fibers (with the length of 4mm and the diameter of 12 microns) at the concentration of 4%, and performing pulping treatment by using three disc mill pulping devices with the pulping power of 180kw to obtain pulp 1 with the pulping degree of 40-degree SR;
(2) the pulp 1 passes through a screening-pulping circulating system and is screened by three screening machines in sequence, and the pulp passing through the screen of the last screening machine is fibrillated fiber.
Wherein, the operation steps of the sieving-refining circulation system are as follows:
(2-1) diluting the concentration of the slurry 1 to 0.03%, screening, sequentially passing through three screening machines, wherein the screens of the three screening machines are 100 meshes, 200 meshes and 300 meshes in sequence, and mixing the slurry intercepted by the screens of the three screening machines to obtain slurry 2;
(2-2) diluting the pulp 2 to 4% of concentration, and performing pulp grinding treatment by using three disc grinders with the pulp grinding power of 180kw to obtain pulp 3 with the pulp grinding degree of 70 DEG SR;
(2-3) slurry 3 was mixed with slurry 1 to form a closed screen-refining circulation system until all the slurry passed through a 300 mesh screen.
Example 2
A fibrillated fiber prepared by the steps of:
(1) controlling the tencel chopped fibers (with the length of 4mm and the diameter of 12 microns) at the concentration of 4%, and performing pulping treatment by using three disc mill pulping devices with the pulping power of 180kw to obtain pulp 1 with the pulping degree of 40-degree SR;
(2) the pulp 1 passes through a screening-pulping circulation system, and the pulp passing through the screen of the last screening machine is fibrillated fiber.
Wherein, the operation steps of the sieving-refining circulation system are as follows:
(2-1) diluting the concentration of the slurry 1 to 0.03%, screening, sequentially passing through three screening machines, wherein the screens of the three screening machines are 100 meshes, 200 meshes and 300 meshes in sequence, and mixing the slurry intercepted by the screens of the three screening machines to obtain slurry 2;
(2-2) diluting the pulp 2 to 4% of concentration, and performing pulp grinding treatment by using three disc grinders with the pulp grinding power of 280kw to obtain pulp 3 with the pulp grinding degree of 95-degree SR;
(2-3) mixing the pulp 3 with the pulp 1 to form a closed screening-refining circulation system until all the pulp passes through a 300-mesh screen.
Example 3
(1) Controlling the tencel chopped fibers (with the length of 4mm and the diameter of 12 microns) at the concentration of 4%, and performing pulping treatment by using three disc mill pulping devices with the pulping power of 250kw to obtain pulp 1 with the pulping degree of 65 DEG SR;
(2) the pulp 1 passes through a screening-pulping circulation system, and the pulp passing through the screen of the last screening machine is fibrillated fiber.
Wherein, the operation steps of the sieving-refining circulation system are as follows:
(2-1) diluting the concentration of the slurry 1 to 0.03%, screening, sequentially passing through three screening machines, wherein the screens of the three screening machines are 100 meshes, 200 meshes and 300 meshes in sequence, and mixing the slurry intercepted by the screens of the three screening machines to obtain slurry 2;
(2-2) diluting the pulp 2 to 4% of concentration, and performing pulp grinding treatment by using three disc grinders with the pulp grinding power of 100kw to obtain pulp 3 with the pulp grinding degree of 70-degree SR;
(2-3) slurry 3 was mixed with slurry 1 to form a closed screen-refining circulation system until all the slurry passed through a 300 mesh screen.
Example 4
(1) Controlling the tencel chopped fibers (with the length of 4mm and the diameter of 12 microns) at the concentration of 4%, and performing pulping treatment by using three disc mill pulping devices with the pulping power of 250kw to obtain pulp 1 with the pulping degree of 65 DEG SR;
(2) the pulp 1 passes through a screening-pulping circulation system, and the pulp passing through the screen of the last screening machine is fibrillated fiber.
Wherein, the operation steps of the sieving-refining circulation system are as follows:
(2-1) diluting the concentration of the slurry 1 to 0.03%, screening, sequentially passing through three screening machines, wherein the screens of the three screening machines are 100 meshes, 200 meshes and 300 meshes in sequence, and mixing the slurry intercepted by the screens of the three screening machines to obtain slurry 2;
(2-2) diluting the pulp 2 to 4% of concentration, and performing pulp grinding treatment by using three disc grinders with the pulp grinding power of 250kw to obtain pulp 3 with the pulp grinding degree of 95-degree SR;
(2-3) slurry 3 was mixed with slurry 1 to form a closed screen-refining circulation system until all the slurry passed through a 300 mesh screen.
Comparative example 1
A fibrillated fiber prepared by a process comprising:
the tencel chopped fibers (with the length of 4mm and the diameter of 12 microns) are controlled to be at the concentration of 4 percent, and are subjected to refining treatment by three disc mill refining equipment with the refining power of 260kw, so that the fibrillated fibers with the beating degree of 70 DEG SR are obtained.
Comparative example 2
A fibrillated fiber prepared by a process comprising:
the tencel chopped fibers (with the length of 4mm and the diameter of 12 microns) are controlled to be at the concentration of 4 percent, and are ground by three disc grinder grinding equipment with the grinding power of 320kw to obtain the fibrillated fibers with the beating degree of 95 DEG SR.
Comparative example 3
A fibrillated fiber prepared by a process comprising:
controlling the concentration of tencel chopped fibers (the length is 4mm, the diameter is 12 mu m) to be 4 percent, carrying out pulp grinding treatment by using three disc grinder pulp grinding equipment, wherein the pulp grinding power is 180kw, and circularly grinding for 10 circles to obtain the fibrillated fibers with the beating degree of 95 DEG SR.
Comparative example 4
A fibrillated fiber prepared by a process comprising:
(1) controlling the tencel chopped fibers (with the length of 4mm and the diameter of 12 microns) at the concentration of 4%, and performing pulping treatment by using three disc mill pulping devices with the pulping power of 250kw to obtain pulp 1 with the pulping degree of 65 DEG SR;
(2) the pulp 1 passes through a screening-pulping circulation system, and the pulp passing through the screen of the last screening machine is fibrillated fiber.
Wherein, the operation steps of the sieving-refining circulation system are as follows:
(2-1) diluting the concentration of the slurry 1 to 0.03%, screening, sequentially passing through three screening machines, wherein the screens of the three screening machines are 100 meshes, 200 meshes and 200 meshes in sequence, and mixing the slurry intercepted by the screens of the three screening machines to obtain slurry 2;
(2-2) diluting the pulp 2 to 4% of concentration, and performing pulp grinding treatment by using three disc grinders with the pulp grinding power of 250kw to obtain pulp 3 with the pulp grinding degree of 95-degree SR;
(2-3) slurry 3 was mixed with slurry 1 to form a closed screen-refining circulation system until all the slurry passed through a 200 mesh screen.
Fibrillated fiber Performance test
The fibrillated fibers prepared in examples 1 to 4 and comparative examples 1 to 2 were subjected to performance tests, the test items and methods of which were as follows:
1. maximum diameter of fiber
Taking fiber slurry with the absolute dry weight of 0.0785g, filtering and drying the fiber slurry through a microporous filter membrane with the diameter of 50mm and the pore diameter of 0.8 mu m to obtain a membrane wafer, observing the surface of the whole membrane wafer by using a scanning electron microscope, and selecting the fiber with the largest diameter from the membrane wafer for measurement.
2. Retention ratio of 150 mesh screen
The fibers intercepted by the 150-mesh screen are mainly main fibers, and the interception proportion of the 150-mesh screen can reflect the proportion of the main fibers in the fibrillated fibers. Diluting the fibrillated fiber to the concentration of 0.1%, pouring 500mL of diluted slurry into a dynamic water filter with a mesh number of 150 meshes, stirring at the rotating speed of 750r/min for 30s, filtering, collecting the slurry retained on the mesh, repeating the above operation, sieving for 2 times, drying and weighing the slurry retained on the mesh for the last time, and weighing W1The retention ratio of the 150-mesh screen is calculated as follows: w is a group of1/0.5×100％。
3. Ionic impedance of diaphragm
The diaphragm ionic impedance may reflect the proportion of microfibrils in the fibrillated fibers, with a greater diaphragm ionic impedance indicating a greater proportion of microfibrils in the fibrillated fibers. And filtering and drying the fiber slurry with the absolute dry weight of 0.0785g by using a microporous filter membrane with the diameter of 50mm and the pore diameter of 0.8 mu m to obtain a membrane disc. Sandwiching the diaphragm wafer (diameter of 16mm) soaked with electrolyte between two stainless steel sheets as working electrode and reference electrode to form a stainless steel sheet/diaphragm/stainless steel sheet system, testing on electrochemical workstation CHI604E by AC impedance method with initial voltage of 0V and scanning frequency of 0-106Hz. And the real axis impedance value at the intersection point of the curve and the real axis in the alternating current impedance spectrum is the diaphragm ionic impedance.
Table 1 fibrillated fiber performance test parameters of the invention
As shown in Table 1, in the examples 1-4 of the present invention, after the chopped fibers are subjected to the first group of refining, the chopped fibers are subjected to the screening-refining circulation system, the number of the screening mesh in the last section is 300, the maximum diameters of the obtained fibrillated fibers are all less than 2.5 μm, the retention ratios of the 150 mesh screens are all 0, and the membrane ionic impedance is between 1.10 and 1.15 omega. Comparative examples 1 and 2 used only the refining treatment, and the maximum fiber diameters were 18.2 μm and 17.8 μm, respectively, the retention ratios on a 150 mesh sieve were 48.3% and 10.8%, respectively, and the ionic impedances on the diaphragms were 1.01 Ω and 1.42 Ω, respectively. It is shown that the proportion of the main fibers can be reduced by only adopting the refining method, but the main fibers with larger diameters still contain the main fibers, the main fibers cannot be completely removed by the refining method, and the refining for a longer time can increase the proportion of the microfibrils and increase the ionic resistance of the diaphragm. In comparative example 3 the chopped fibers were processed through a screen-refining circulation system after the first group of refining, but the final stage was 200 mesh screen and the maximum diameter of the resulting fibrillated fibers was 5.3 μm.
The action mechanism of the invention is as follows: the fibrillatable fibers have a sheath-core structure with a core layer of a highly oriented and ordered multi-fibril structure. The fibrils are continuously stripped from the trunk fibers during the refining process and the fibrillated fibers can be considered to consist of trunk fibers and stripped fibrils, including macrofibrils and microfibrils. Therefore, the fiber skin is stripped through the first group of refining treatment, the fiber length is properly reduced, and the pulp 1 is obtained; the pulp 1 contains more main fibers with a multi-stage branch structure, and the fibers have strong interception capability, so that the main fibers are screened step by adopting a group of screens with gradually increased screening meshes, a great amount of fibrils can be prevented from being intercepted, and the screening efficiency is improved; the pulp 2 intercepted by the screen contains a large number of main fibers, the further fibrillation treatment is carried out by a second group of pulping equipment to obtain pulp 3, and the pulp 3 and the pulp 1 are mixed to continue the sieving-pulping circulation.
The fibrillated fiber prepared by the method can be applied to papermaking of a battery diaphragm or a capacitor diaphragm, and the battery diaphragm or the capacitor diaphragm with lower ionic resistance can be obtained.
The above description is only for the preferred embodiment of the present invention, but the present invention should not be limited to the embodiment and the disclosure of the drawings, and therefore, all equivalent or modifications that do not depart from the spirit of the present invention are intended to fall within the scope of the present invention.
Claims (7)
1. A method for preparing fibrillated fibers is characterized by comprising the following steps:
s1, controlling the concentration of the chopped fibers to be 1-30%, and performing pulping treatment by using a first group of pulping equipment to obtain pulp 1 with the beating degree of 40-65 DEG SR;
s2, diluting the concentration of the pulp 1 to 0.01-0.05% for screening treatment, screening by a group of screening devices, mixing the pulp intercepted by the screens of the group of screening devices to obtain pulp 2, and taking the pulp passing through the screen of the last screening device as fibrillated fiber;
s3, diluting the pulp 2 to the concentration of 1-30%, and refining the pulp by a second group of refining equipment to 70-95 DEG SR to obtain pulp 3;
and S4, mixing the pulp 3 with the pulp 1 to form a closed sieving-refining circulating system, and repeating the steps S1-S4 until the pulp completely passes through the screen of the last sieving device.
2. The method of preparing fibrillated fibers according to claim 1, wherein: the chopped fiber is one or more of tencel fiber, poly-p-phenylene terephthamide fiber, polyacrylonitrile fiber or poly-p-phenylene benzoxazole fiber.
3. The method of preparing fibrillated fibers according to claim 1, wherein: the refining equipment is one or more of a disc refiner, a conical refiner, a cylindrical refiner or a trough refiner.
4. The method of preparing fibrillated fibers according to claim 1, wherein: the screening equipment is formed by connecting a plurality of vibrating screens or filters in series, wherein the mesh number of the vibrating screens is increased in sequence.
5. A fibrillated fiber producing method in accordance with claim 1, characterized in that: the screen mesh number of the screening equipment is 100-300 meshes, the screen mesh number of the first screening equipment is 100 meshes, the screen mesh number of the last screening equipment is 300 meshes, and the screen mesh number of the former screening equipment is smaller than that of the latter screening equipment.
6. The method of preparing fibrillated fibers according to claim 1, wherein: the maximum diameter of the fibrillated fibres obtained after screening by the last vibrating screen mesh is less than 2.5 μm.
7. Use of fibrillated fibres, characterized in that: use of the fibrillated fibers obtained according to any of claims 1-6 for the manufacture of battery or capacitor separators.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210386135.0A CN114703699B (en) | 2022-04-13 | 2022-04-13 | Preparation method and application of fibrillated fibers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210386135.0A CN114703699B (en) | 2022-04-13 | 2022-04-13 | Preparation method and application of fibrillated fibers |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114703699A true CN114703699A (en) | 2022-07-05 |
| CN114703699B CN114703699B (en) | 2023-04-25 |
Family
ID=82173906
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210386135.0A Active CN114703699B (en) | 2022-04-13 | 2022-04-13 | Preparation method and application of fibrillated fibers |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114703699B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115418878A (en) * | 2022-08-17 | 2022-12-02 | 中集竹链科技有限公司 | Material screening system and screening method |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000273788A (en) * | 1999-01-21 | 2000-10-03 | Toray Ind Inc | Para-aromatic polyamide fiber paper and its production |
| CN101137734A (en) * | 2005-01-10 | 2008-03-05 | 纳幕尔杜邦公司 | Slurries containing microfiber and micropowder, and methods for using and making same |
| JP2008255550A (en) * | 2007-03-13 | 2008-10-23 | Teijin Techno Products Ltd | Water-swelling fibrillated fiber and sheet-like material using the same |
| CN101530700A (en) * | 2008-09-28 | 2009-09-16 | 华南理工大学 | Wet method forming micropore filtration separation material and preparation method and application thereof |
| US20100310868A1 (en) * | 2007-10-23 | 2010-12-09 | Teijin Aramid Gmbh | Refined fiber |
| WO2011157516A1 (en) * | 2010-06-15 | 2011-12-22 | Redco S.A. | Cellulose fibres for fibre-reinforced cement products |
| CN103966891A (en) * | 2014-04-23 | 2014-08-06 | 华南理工大学 | Method for preparing fiber pulp and prepared fiber pulp |
| CN105164337A (en) * | 2013-05-03 | 2015-12-16 | 帝人芳纶有限公司 | Process to manufacture a mixture of p-aramid pulp with chopped fibers, mixture and its use |
-
2022
- 2022-04-13 CN CN202210386135.0A patent/CN114703699B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000273788A (en) * | 1999-01-21 | 2000-10-03 | Toray Ind Inc | Para-aromatic polyamide fiber paper and its production |
| CN101137734A (en) * | 2005-01-10 | 2008-03-05 | 纳幕尔杜邦公司 | Slurries containing microfiber and micropowder, and methods for using and making same |
| JP2008255550A (en) * | 2007-03-13 | 2008-10-23 | Teijin Techno Products Ltd | Water-swelling fibrillated fiber and sheet-like material using the same |
| US20100310868A1 (en) * | 2007-10-23 | 2010-12-09 | Teijin Aramid Gmbh | Refined fiber |
| CN101530700A (en) * | 2008-09-28 | 2009-09-16 | 华南理工大学 | Wet method forming micropore filtration separation material and preparation method and application thereof |
| WO2011157516A1 (en) * | 2010-06-15 | 2011-12-22 | Redco S.A. | Cellulose fibres for fibre-reinforced cement products |
| CN105164337A (en) * | 2013-05-03 | 2015-12-16 | 帝人芳纶有限公司 | Process to manufacture a mixture of p-aramid pulp with chopped fibers, mixture and its use |
| CN103966891A (en) * | 2014-04-23 | 2014-08-06 | 华南理工大学 | Method for preparing fiber pulp and prepared fiber pulp |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115418878A (en) * | 2022-08-17 | 2022-12-02 | 中集竹链科技有限公司 | Material screening system and screening method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114703699B (en) | 2023-04-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6905798B2 (en) | Separator for electrochemical device and method for producing the same | |
| US11078627B2 (en) | High tensile strength paper suitable for use in electrochemical cells | |
| JP5876373B2 (en) | Electrochemical element separator and electrochemical element using the same | |
| CN114703699B (en) | Preparation method and application of fibrillated fibers | |
| KR102662350B1 (en) | Separator for electrochemical devices and electrochemical devices | |
| CN110656529B (en) | Fine fiber, preparation method and application thereof, and preparation method of diaphragm for electrical equipment | |
| JP2016001672A (en) | Separator for capacitor | |
| JP2016001663A (en) | Manufacturing method of separator for electrochemical element and separator for electrochemical element | |
| JP5594844B2 (en) | Electrochemical element separator | |
| JP2023086729A (en) | Alkaline battery separator with controlled pore size | |
| KR101915941B1 (en) | Separator for alkaline batteries | |
| JP2006045758A (en) | Parenchyma cell fiber and synthetic fiber-containing nonwoven fabric | |
| JP2017174928A (en) | Separator for solid electrolytic capacitor | |
| JP2016171048A (en) | Lithium ion secondary battery separator and lithium ion secondary battery arranged by use thereof | |
| JP5594845B2 (en) | Electrochemical element separator | |
| JP2003059766A (en) | Separator for electrochemical element and manufacturing method thereof | |
| JP2021158273A (en) | Separator for electrochemical element | |
| JP2001300225A (en) | Filter medium and method for manufacturing the same | |
| CN114709555A (en) | Lithium ion battery diaphragm substrate and preparation method thereof | |
| CN114824657A (en) | Lithium ion battery composite diaphragm and preparation method thereof | |
| EP4084027A1 (en) | Separator for electrochemical elements | |
| CN114678654A (en) | Lithium ion battery diaphragm and preparation method thereof | |
| JPH11219693A (en) | Separator for battery | |
| JP2022148271A (en) | Method for producing fibrillated solvent-spun cellulose fiber | |
| JP2001035754A (en) | Separator for electric double-layer capacitor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |