CN114534362B - Charged deep-layer filter paper board and preparation method thereof - Google Patents
Charged deep-layer filter paper board and preparation method thereof Download PDFInfo
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- CN114534362B CN114534362B CN202210110823.4A CN202210110823A CN114534362B CN 114534362 B CN114534362 B CN 114534362B CN 202210110823 A CN202210110823 A CN 202210110823A CN 114534362 B CN114534362 B CN 114534362B
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- 239000011087 paperboard Substances 0.000 title claims abstract description 153
- 238000002360 preparation method Methods 0.000 title abstract description 7
- 229920003043 Cellulose fiber Polymers 0.000 claims abstract description 179
- 239000007788 liquid Substances 0.000 claims abstract description 97
- 239000012466 permeate Substances 0.000 claims abstract description 17
- 238000007599 discharging Methods 0.000 claims abstract description 16
- 230000008859 change Effects 0.000 claims abstract description 8
- 230000000630 rising effect Effects 0.000 claims abstract description 6
- 239000006185 dispersion Substances 0.000 claims description 67
- 239000000047 product Substances 0.000 claims description 65
- 239000002002 slurry Substances 0.000 claims description 65
- 238000011118 depth filtration Methods 0.000 claims description 62
- 238000000034 method Methods 0.000 claims description 60
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 53
- 238000002156 mixing Methods 0.000 claims description 45
- 238000001035 drying Methods 0.000 claims description 42
- 230000035699 permeability Effects 0.000 claims description 42
- 239000011230 binding agent Substances 0.000 claims description 32
- 238000004537 pulping Methods 0.000 claims description 30
- 239000002245 particle Substances 0.000 claims description 26
- 239000000654 additive Substances 0.000 claims description 25
- 230000000996 additive effect Effects 0.000 claims description 24
- 238000004519 manufacturing process Methods 0.000 claims description 24
- 238000003756 stirring Methods 0.000 claims description 22
- 239000000344 soap Substances 0.000 claims description 21
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 20
- 239000000835 fiber Substances 0.000 claims description 20
- 239000011111 cardboard Substances 0.000 claims description 19
- 238000007493 shaping process Methods 0.000 claims description 16
- 230000005540 biological transmission Effects 0.000 claims description 15
- 238000005520 cutting process Methods 0.000 claims description 15
- 238000004080 punching Methods 0.000 claims description 15
- 229920000877 Melamine resin Polymers 0.000 claims description 7
- 229920005989 resin Polymers 0.000 claims description 7
- 239000011347 resin Substances 0.000 claims description 7
- IMNIMPAHZVJRPE-UHFFFAOYSA-N triethylenediamine Chemical compound C1CN2CCN1CC2 IMNIMPAHZVJRPE-UHFFFAOYSA-N 0.000 claims description 6
- 229920002401 polyacrylamide Polymers 0.000 claims description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 4
- 238000000465 moulding Methods 0.000 claims description 4
- 229920001661 Chitosan Polymers 0.000 claims description 3
- FAGUFWYHJQFNRV-UHFFFAOYSA-N tetraethylenepentamine Chemical compound NCCNCCNCCNCCN FAGUFWYHJQFNRV-UHFFFAOYSA-N 0.000 claims description 3
- 238000002834 transmittance Methods 0.000 claims description 3
- 239000005909 Kieselgur Substances 0.000 claims description 2
- 239000000377 silicon dioxide Substances 0.000 claims description 2
- 238000013019 agitation Methods 0.000 claims 2
- 238000001914 filtration Methods 0.000 abstract description 78
- GNBHRKFJIUUOQI-UHFFFAOYSA-N fluorescein Chemical compound O1C(=O)C2=CC=CC=C2C21C1=CC=C(O)C=C1OC1=CC(O)=CC=C21 GNBHRKFJIUUOQI-UHFFFAOYSA-N 0.000 abstract description 28
- 239000001043 yellow dye Substances 0.000 abstract description 27
- 239000000853 adhesive Substances 0.000 abstract description 22
- 230000001070 adhesive effect Effects 0.000 abstract description 22
- 239000012634 fragment Substances 0.000 description 17
- 238000011072 cell harvest Methods 0.000 description 15
- 238000007666 vacuum forming Methods 0.000 description 12
- 238000005086 pumping Methods 0.000 description 10
- 238000001179 sorption measurement Methods 0.000 description 9
- 230000035515 penetration Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 6
- 239000000123 paper Substances 0.000 description 6
- 102000004169 proteins and genes Human genes 0.000 description 6
- 108090000623 proteins and genes Proteins 0.000 description 6
- 206010061592 cardiac fibrillation Diseases 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 230000002600 fibrillogenic effect Effects 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 239000000975 dye Substances 0.000 description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 3
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- 238000004113 cell culture Methods 0.000 description 2
- 238000005352 clarification Methods 0.000 description 2
- 239000000706 filtrate Substances 0.000 description 2
- 238000003306 harvesting Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 235000018102 proteins Nutrition 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 241000700605 Viruses Species 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000001174 ascending effect Effects 0.000 description 1
- 229960000074 biopharmaceutical Drugs 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000003833 cell viability Effects 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000000084 colloidal system Substances 0.000 description 1
- 239000013065 commercial product Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000004043 dyeing Methods 0.000 description 1
- 238000001493 electron microscopy Methods 0.000 description 1
- 239000012632 extractable Substances 0.000 description 1
- 238000005189 flocculation Methods 0.000 description 1
- 230000016615 flocculation Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 150000004676 glycans Chemical class 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000002121 nanofiber Substances 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920001282 polysaccharide Polymers 0.000 description 1
- 239000005017 polysaccharide Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 235000004252 protein component Nutrition 0.000 description 1
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- 238000010008 shearing Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000000108 ultra-filtration Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D36/00—Filter circuits or combinations of filters with other separating devices
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
- B01D35/06—Filters making use of electricity or magnetism
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D39/00—Filtering material for liquid or gaseous fluids
- B01D39/14—Other self-supporting filtering material ; Other filtering material
- B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
- B01D39/18—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being cellulose or derivatives thereof
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
- C12M33/00—Means for introduction, transport, positioning, extraction, harvesting, peeling or sampling of biological material in or from the apparatus
- C12M33/14—Means for introduction, transport, positioning, extraction, harvesting, peeling or sampling of biological material in or from the apparatus with filters, sieves or membranes
-
- 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
- D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
-
- 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
-
- 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
- D21H27/08—Filter paper
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2221/00—Applications of separation devices
- B01D2221/10—Separation devices for use in medical, pharmaceutical or laboratory applications, e.g. separating amalgam from dental treatment residues
Abstract
The invention discloses a charged deep filtration paperboard and a preparation method thereof, and relates to the field of deep filtration media, the deep filtration paperboard comprises a paperboard body, wherein the paperboard body comprises cellulose fibers, a filter aid and an adhesive, the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate liquid, and the tightness of the first side surface to the second side surface is in continuous rising gradient change; the quantity of the soap yellow dye liquor in the area from the third thickness of the first side is L1, the quantity of the soap yellow dye liquor in the area from the third thickness of the second side is L2, and the quantity of L1:L2 is 1:1.2-3.
Description
Technical Field
The invention relates to the field of depth filtration media, in particular to a charged depth filtration paperboard and a preparation method thereof.
Background
After long development, cell culture technology has become an important technical means for producing proteins, and in the field of cell culture, the current commonly used cell harvest liquid harvesting methods include flocculation, precipitation, centrifugation and depth filtration, wherein the depth filtration paper board is usually composed of cellulose fibers, diatomite and a binder, and can be used for filtration in a depth range. In general, the cell harvest contains a large amount of whole cells, cell debris, and desired target proteins and other biological components, and in order to separate the desired target proteins and other biological components, it is necessary to perform downstream purification and filtration steps such as clarification filtration, ultrafiltration, chromatography and the like, where clarification filtration is the first step of downstream purification in the biopharmaceutical process to remove impurities such as cell debris, large particle residues, colloids or precipitates, polysaccharides, pigments, host Cell Proteins (HCPs), and biomacromolecule DNA, so as to reduce membrane pollution during subsequent filtration, increase flux, prolong a cleaning cycle and service life, reduce running cost, and improve production efficiency. In the process of filtering the cell harvest liquid through the deep-layer filtering paper board, biological components with larger diameters such as whole cells or cell fragments and the like can be intercepted by the deep-layer filtering paper board, DNA, HCP and the like can be adsorbed and separated by the deep-layer filtering paper board in a charge adsorption mode, so that target proteins can be separated from the whole cells, the cell fragments, the DNA, the HCP and the like through the deep-layer filtering paper board, and target protein collection is realized. However, the existing depth filtration paper board cannot simultaneously meet the high retention rate of intact cells and cell fragments and the high adsorption amount of DNA, HCP and the like, and shows little turbidity reduction after filtration, meanwhile, the depth filtration paper board has lower utilization rate in the thickness direction, is easy to block, and has faster pressure difference rise during filtration use.
Disclosure of Invention
The invention aims to provide a charged deep-layer filter paper board with good filtering effect and high utilization rate and a preparation method thereof.
In order to achieve the above purpose, the invention adopts the following technical scheme:
a charged depth filtration paperboard comprising a paperboard body for the paperboard body comprising cellulosic fibers, a filter aid and a binder, the cellulosic fibers being bound by the binder and wrapped around the filter aid, characterized in that:
the paperboard body has a first side for receiving a liquid to be filtered, and
a second side surface for discharging the permeate,
the tightness of the first side surface to the second side surface shows continuously rising gradient change;
the paperboard body is positively charged, and the charge quantity is continuously increased from the first side surface to the second side surface in a gradient manner;
taking a cardboard body, constantly supplying soap Huang Ranye with concentration of 20ppm to the first side at a speed of 5ml/min, and when the transmittance of the permeation solution at 430nm is reduced to 95%, the permeation amount of soap Huang Ranye is 300-6500 μg/cm 3 ；
Wherein:
the transmission from the area of one third of the thickness of the first side is L1,
the transmission amount from the region of one third of the thickness of the second side surface is L2,
The ratio of L1 to L2 is 1:1.2-3.
Cellulose fibers are bonded through an adhesive to form a framework, and a filter aid is wrapped in the framework to form a deep-layer filter paper board, meanwhile, a positively charged adhesive or a charge additive is added to endow the deep-layer filter paper board with positive charge, in the use process, pores among the cellulose fibers can trap and remove large-particle-size impurities such as cells and larger cell fragments, positive charges brought by the charged adhesive or the charge additive can adsorb cell fragments with smaller diameters or undesired protein components such as DNA and HCP, and hydrophobicity brought by the filter aid can play a certain role in adsorbing DNA, so that undesired biological components can be removed from the cell harvest liquid by the deep-layer filter paper board through trapping or adsorbing after the cell harvest liquid to be filtered, namely the cell harvest liquid passes through the deep-layer filter paper board, and thus the cell harvest liquid containing desired biological components such as antibodies, viruses and the like is obtained.
When the filtering is carried out by the team of the invention, the rated pressure difference is easy to reach, namely the deep-layer filtering paper board can be blocked quickly, and the reason is that the content of cell fragments in the undesirable biological components of the cell harvest liquid is higher, the diameter size distribution is wider, and under the condition that the electric charge of the upper layer of the deep-layer filtering paper board is relatively higher, the relatively fine cell fragments which are mainly removed through adsorption are easy to fill the dirt containing space of the upper layer of the deep-layer filtering paper board together with large cell fragments and cells too quickly, so that the utilization rate of the lower layer of the deep-layer filtering paper board is reduced, and the integral filtering is not facilitated.
In the deep filtration paperboard, the tightness of the first side surface to the second side surface is continuously increased in gradient, and the electric charge quantity is continuously increased in gradient from the first side surface to the second side surface, wherein the tightness of the first side surface is lower, and the electric charge content is smaller, so that the deep filtration paperboard near the first side surface has larger dirt receiving space, more cells and larger cell fragments can be trapped and contained, namely, the major effect of the deep filtration paperboard is to trap and contain larger impurities such as the cells and the cell fragments, and meanwhile, relatively smaller cell fragments are relatively easy to pass due to weaker electric charge adsorption, and do not occupy excessive dirt receiving space, while the deep filtration paperboard near the second side surface is relatively larger in tightness, and the gap is relatively smaller, so that a flow path is relatively narrower and more tortuous, and the cell harvest liquid is more contacted with fibers during filtering at the place, and meanwhile, the electric charge content at the deep filtration paperboard is also higher, so that the small cell fragments can be sufficiently removed through adsorption (and the precision is higher, and the small cell fragments can be trapped and have small diameter of the filter paper plate and can not fully play the role of absorbing the small-size of the DNA dirt, and the filter liquid can not fully play the role of filtering the filter liquid, even though the small filter liquid is required to have small diameter of the filter effect after the filter liquid is filtered at the deep filtration.
Therefore, when the deep filtration paperboard is adopted to filter the cell harvest liquid, firstly, the whole cells and large cell fragments in the cell harvest liquid are greatly trapped, and relatively small cell fragments are less adsorbed due to relatively weak charge adsorption effect, so that a dirt receiving space close to a first side surface in the deep filtration paperboard can be used for more containing the whole cells and the large cell fragments, and excessively quick blockage is avoided; therefore, compared with the deep-layer filter paper board with more equal charge content, the deep-layer filter paper board provided by the invention is not easy to be blocked too fast, the utilization rate is higher, the turbidity of filtrate is lower, and HCP and DNA residues are relatively lower.
As a preferred alternative to this,
the transmission L1 of the region of one third of the thickness from the first side is 120-2200 mu g/cm 3 ，
The transmission L2 from the region of one third of the thickness of the second side is 150-4200 μg/cm 3 。
Preferably, the tightness of the paperboard body is 0.26-0.38g/cm 3 ；
Wherein:
the tightness of one third of the thickness from the first side is t1,
the tightness of one third of the thickness from the second side is t2,
the ratio of t1 to t2 is 1:1.1-1.7.
Preferably, the tightness of the paperboard body is 0.26-0.38g/cm 3 ；
Wherein:
the tightness t1 of one third of the thickness of the first side surface is 0.20-0.35g/cm 3 ；
The tightness t2 of one third of the thickness of the second side surface is 0.29 to 0.40g/cm 3 。
In the invention, the tightness of one third of the thickness of the first side surface is lower, the dirt receiving space is larger, the tightness of one third of the thickness of the second side surface is larger, the precise adsorption is facilitated, and the method is suitable for various cell harvest liquids when the tightness is set in the range.
Preferably, in the cardboard body:
the porosity of one third of the thickness from the first side is n1,
the porosity from the second side one third of the thickness is n2,
the n1 to n2 is 1.1-5:1.
Preferably, in the cardboard body:
the porosity of one third of the thickness from the first side is 25-70%;
the porosity of one third of the thickness from the second side is 5-60%.
In the invention, the tightness of one third of the thickness from the first side surface is lower, the porosity is relatively larger, the dirt receiving space is larger, the tightness of one third of the thickness from the second side surface is larger, the porosity is relatively lower, the precise adsorption is facilitated, and the method is suitable for various cell harvesting liquids when the tightness and the porosity are arranged in the above range.
Preferably, the cellulose fiber content in the paperboard body is 10-60wt%, the filter aid content is 30-80wt% and the binder content is 1-10wt%.
When the content of each component is within the limit range of the invention, the prepared deep filtration paperboard has better filtration performance.
Preferably, the cellulose fibers comprise 20 to 40wt% of coarse cellulose fibers and 60 to 80wt% of fine cellulose fibers.
Preferably, the diameter of the crude cellulose fiber is 1-50 μm; the diameter of the fine cellulose fiber is 5-150nm.
The cellulose fiber consists of coarse cellulose fiber and fine cellulose fiber, wherein the coarse cellulose fiber is used for forming a deep filtration paperboard framework, the fine cellulose fiber is wrapped outside the coarse cellulose fiber and used for improving the overall accuracy, and when the fiber diameter is within the limit range of the invention, the deep filtration paperboard with the charge quantity changing in a continuous ascending gradient from the first side surface to the second side surface is easier to prepare.
Preferably, the crude cellulose fiber has a Canadian freeness of 450 to 800ml; the Canadian freeness of the fine cellulose fiber is 50-325ml.
When the Canadian freeness of the crude fiber and the superfine nanofiber is too high, the fibrillation degree is too low, and the exposed hydroxyl, carboxyl and other active groups are few, so that the fiber is not easy to combine with an adhesive or a charge additive; meanwhile, the strength of the deep filtration medium is easily insufficient, the deep filtration medium is easily contracted in the drying process, and when the Canadian freeness is too low, the degree of fibrillation is too high, the water permeability of the deep filtration medium is easily reduced, and the filtration pressure difference is excessively large in use.
Preferably, the filter aid comprises one or more of diatomaceous earth, silica, activated carbon.
Preferably, the filter aid has an average particle diameter D50 of 0.05 to 80. Mu.m.
Preferably, the filter aid has a permeability of between 0.05 and 6 dracy.
The filter aid permeability is too high, the deep filtration paper board can not have better interception or adsorption effect, the filter aid permeability is too low, the flow rate of the deep filtration paper board is slower, and the resistance is too high during filtration.
Preferably, the binder comprises one or more of melamine-formaldehyde resin, polyamide-epichlorohydrin resin, glyoxal-polyacrylamide.
Preferably, the paperboard body further comprises a charge additive, and the total content of the charge additive and the binder in the paperboard body is 1-10wt%.
In the invention, positive charges can be given to the deep-layer filter paper board by adding the charge additive, the total content of the charge additive and the binder is too small, which easily causes insufficient charge content or insufficient strength, and the total content is too large, which easily causes excessive extractables of the deep-layer filter paper board.
Preferably, the charge additive comprises one or more of triethylene diamine, tetraethylene pentamine and chitosan.
Preferably, the wet strength of the paperboard body is between 150 and 400 Kpa.
Preferably, the thickness of the cardboard body is set between 1.5 and 6 mm.
A method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain coarse cellulose fiber slurry and fine cellulose fiber slurry;
s2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding a filter aid and a binder, and then stirring to form a dispersion liquid with uniform concentration;
s3: molding, namely placing the stirred dispersion liquid on the upper surface of a screen, and vacuumizing from the lower surface side of the screen to form negative pressure to form a primary finished product;
s4: drying, namely shaping and drying the primary finished product;
s5: punching, and cutting the primary product to form a finished product.
In the invention, after the dispersion liquid is placed on the upper surface of a screen, vacuum is pumped from the lower surface side of the screen to form negative pressure, water in the slurry is pumped away to form a primary product, in the process, the suction force is larger at the position closer to the screen, so that the tightness of the deep-layer filter paper board is higher at the position closer to the screen, and the cellulose fibers consist of the coarse cellulose fibers and the fine cellulose fibers, wherein the fine fibers are easier to gather at the position closer to the screen along with the suction force than the coarse fibers, the diameter of the fine cellulose fibers is small, the Canadian freeness is lower, the degree of fibrillation is high, so that the exposed hydroxyl groups are more, the generated negative charge is more, and the charge amount is easier to attract the adhesion of a charge modifying agent compared with the coarse cellulose fibers, so that the deep-layer filter paper board prepared by the invention shows a gradient change continuously from the first side to the second side.
Preferably, the concentration of the crude cellulose fiber slurry in step S1 is 4-6wt%; the fine cellulose fiber slurry has a concentration of 1 to 3wt%.
The smaller diameter fibers are more difficult to disperse, and thus a lower concentration of fine cellulose fiber dispersion is required.
Preferably, the stirring temperature in the stirring in the step S2 is 15-50 ℃; the stirring time is 0.5h-4h.
When the deep filtration paper board is prepared, the concentration of the dispersion liquid is more uniform when the stirring temperature and the stirring time are within the limit range of the invention; if the temperature is too low, the adhesive and the charge additive may be solidified or agglomerated, and cannot be uniformly dispersed, or require more dispersing time and larger shearing force for stirring; the excessive temperature causes excessive activation of the adhesive and the charge additive, even polymerization or solidification phenomenon occurs, and the adhesive and the charge additive cannot be uniformly dispersed or are free in the dispersion liquid, so that the dispersion is uneven, and the adhesive and charge modification effects are poor.
Preferably, a charge additive is also added in step S2.
Preferably, the shaping in step S3 is a two-stage vacuum:
the first stage: the vacuumizing vacuum degree is-10 to-60 Kpa;
And a second stage: the vacuumizing vacuum degree is-50 to-100 KPa.
When the vacuum degree in the limit range of the invention is vacuumized, deep-layer filtering paper boards with good tightness and gradient distribution of electric charge quantity can be formed, the vacuum degree is too small, and the deep-layer filtering paper boards are too loose, so that the strength is insufficient; the deep filtration paper board is too high in vacuum degree, the change of tightness and charge gradient is not obvious, the invention is divided into two stages of vacuumizing, the vacuum degree is increased stepwise, a large amount of initial water loss can be prevented, additives such as filter aid and the like are taken away, meanwhile, the excessive stacking density of the bottom layer of the initial paper board can be prevented, the suction of upper water is prevented, the upper water is prevented from flowing in a scattered manner, and the uneven surface thickness is caused.
Preferably, in step S3, vacuum is applied until the water content of the primary product is less than 120%.
If the water content of the primary product is too large, the deep-layer filtering paper board is too loose after final drying, which is easy to cause insufficient strength, while if the water content is too small, the adhesive, the charge additive and the like which are not completely adsorbed are easy to be extracted, so that the final performance of the deep-layer filtering paper board is reduced.
Preferably, in step S3, the screen is a double layer, one layer has a mesh size of 20-120 mesh, the other layer has a mesh size of 80-500 mesh, and the mesh size of the layer close to the dispersion is smaller than the mesh size of the layer far away from the dispersion.
The invention adopts a double-layer screen vacuumizing mode, wherein the screen close to one layer of the dispersion liquid plays a role in blocking fibers, so that the fibers are prevented from being sucked away by water flow, the screen mesh number of the screen far away from the dispersion liquid is larger, and the filter aids with different particle sizes can be prevented from losing.
Preferably, the drying in step S3 is performed until the water content is less than 10%.
Preferably, the drying temperature is 60-200 ℃ and the drying time is 3-8h.
The drying temperature and time influence the bonding between the binder and the cellulose fibers, the drying temperature is too low, and the bonding degree between the binders and the cellulose fiber molecules is reduced, so that the strength is influenced; too high a temperature may cause the mutual reaction or decomposition of the groups between the binders, and may also cause excessive shrinkage of cellulose, color change on the surface of the board, or insufficient strength.
The tightness of the first side surface to the second side surface in the deep filtration paperboard prepared by the invention shows continuously rising gradient change, and the electric charge quantity also shows continuously rising gradient change from the first side surface to the second side surface, so that relatively tiny cell fragments are less adsorbed at the position close to the first side surface during filtration, thereby preventing the deep filtration paperboard from being blocked too fast and greatly improving the overall utilization rate of the deep filtration paperboard.
Detailed Description
In order that the above-recited objects, features and advantages of the invention will be more clearly understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those described herein, and therefore the scope of the present invention is not limited to the specific embodiments disclosed below.
Example 1: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 4wt% of coarse cellulose fiber slurry and 1wt% of fine cellulose fiber slurry;
s2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding filter aid diatomite and binder melamine-formaldehyde resin, and stirring for 2 hours at 30 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 10wt% of coarse cellulose fibers, 30wt% of fine cellulose fibers, 55wt% of filter aid and 5wt% of adhesive;
The Canadian freeness of the crude cellulose fiber is 450ml, and the diameter is 10-20 mu m; the Canadian freeness of the fine cellulose fiber is 70ml, and the diameter is 15-25nm; the average particle diameter D50 of the filter aid is 4 mu m, and the permeability is 0.2dracy;
s3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far away from the dispersion liquid is 400, the number of layers close to the dispersion liquid is 110, and vacuumizing from the lower surface side of the screen to form negative pressure until the water content is less than 120%, so as to form a primary finished product;
the steps of vacuum forming are as follows:
the first stage: the vacuumizing vacuum degree is-50 Kpa,
and a second stage: the vacuumizing vacuum degree is-90 KPa;
s4: drying, namely shaping and drying the primary finished product for 5 hours at 130 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the prepared deep filtration paperboard has the precision of 0.5 mu m and the wet strength of 363Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm has a transmission of 6230 μg/cm 3 ；
Wherein:
the soap yellow dye liquor permeability from the area of one third of the thickness of the first side is 1185 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.32g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity is 28%;
the soap yellow dye liquor permeability from the area with the thickness of one third of the second side surface is 2387 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.38g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 12%.
The soap yellow dye liquor permeation test method comprises the following steps: a depth filter paper plate of a specific thickness and diameter was used to constantly feed soap Huang Ranye having a concentration of 20ppm to the first side at a rate of 5ml/min, and when the transmittance of the permeate at 430nm was reduced to 95%, the mass of soap Huang Ranye permeated at this time was calculated to obtain a soap yellow dye liquor permeability. Meanwhile, the total layering charge amount is lower than that of the whole layer because the overall layering utilization rate of the whole layer of deep filtering paperboard is relatively low.
In the invention, after the morphology of the deep filtration medium structure is characterized by using a scanning electron microscope, the fiber diameter, the particle diameter of the filter aid and the like can be measured by using computer software (such as Matlab, NIS-Elements and the like) or a manual measurement mode so as to measure the average diameter, the particle diameter and the like of the fiber and the filter aid actually used by the invention; during the preparation of the depth filter media, the distribution of the filter aid is maintained substantially uniform in the direction perpendicular to the depth filter media thickness, i.e., the depth filter media plane, and the overall level in the plane may be reflected by the average fiber diameter or filter aid particle size of the partial regions in the respective planes. In practice, the surface of the film may be characterized by electron microscopy to obtain a corresponding SEM image, and since the surface distribution is substantially uniform, a certain area, e.g. 1 μm, may be selected 2 (1 μm by 1 μm) or 10mm 2 (100 μm by 100 μm), etc., and the specific area size is determined according to the actual situation, and the average value of the fiber diameter or the particle diameter of the filter aid on the area is measured by corresponding computer software or manually so as to represent the average value of the surface; of course, the person skilled in the art can also obtain the above parameters by other measuring means, which are only used as reference.
Wet strength test method is referred to GB/T465.1-2008.
The precision testing method comprises the following steps: and (3) placing a proper amount of IS0 12103-1A4 standard particles into pure water to prepare a suspension of 5mg/L, wetting depth filtration filter paper, then allowing the suspension to pass through at a speed of 10L/min, and calculating the interception efficiency, wherein the interception efficiency= (1-the number of particles with the downstream larger than diameter X/the number of particles with the upstream larger than diameter X) ×100% and the particle size of the particles with the interception efficiency of more than or equal to 95% are the precision.
Example 2: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 4wt% of coarse cellulose fiber slurry and 1wt% of fine cellulose fiber slurry;
s2: mixing, mixing the crude cellulose fiber slurry and the fine cellulose fiber slurry, adding filter aid diatomite and binder polyamide-epichlorohydrin resin, and stirring for 3 hours at 20 ℃ to form a dispersion liquid with uniform concentration;
Wherein the contents of the components are as follows: 7wt% of coarse cellulose fibers, 28wt% of fine cellulose fibers, 62wt% of filter aid and 3wt% of adhesive;
the Canadian freeness of the crude cellulose fiber is 480ml, and the diameter is 15-25 mu m; the Canadian freeness of the fine cellulose fiber is 80ml, and the diameter is 20-30nm; the average particle diameter D50 of the filter aid is 8 mu m, and the permeability is 0.3dracy;
s3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far away from the dispersion liquid is 400, the number of layers close to the dispersion liquid is 110, and vacuumizing from the lower surface side of the screen to form negative pressure until the water content is less than 120%, so as to form a primary finished product;
the steps of vacuum forming are as follows:
the first stage: the vacuum degree of the vacuum pumping is-45 Kpa,
and a second stage: the vacuumizing vacuum degree is-95 KPa;
s4: drying, namely shaping and drying the primary finished product for 7 hours at the temperature of 80 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the precision of the prepared deep filtration paperboard is 1 mu m, and the wet strength is 331Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm has a transmission of 5928 μg/cm 3 ；
Wherein:
soap yellow dyeing from area of one third thickness of first sideThe liquid permeability is 833 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.31g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity is 32%;
the soap yellow dye liquor permeability from the second side area with the thickness of one third is 1974 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.36g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 15%.
Example 3: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 4wt% of coarse cellulose fiber slurry and 1wt% of fine cellulose fiber slurry;
s2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding filter aid diatomite, binder polyamide-epichlorohydrin resin and charge additive tetraethylenepentamine, and stirring for 0.5h at 50 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 15wt% of coarse cellulose fibers, 38wt% of fine cellulose fibers, 40wt% of auxiliary filter, 5wt% of adhesive and 2wt% of charge additive;
the Canadian freeness of the crude cellulose fiber is 500ml, and the diameter is 15-20 mu m; the Canadian freeness of the fine cellulose fiber is 110ml, and the diameter is 25-35nm; the average particle diameter D50 of the filter aid is 3 mu m, and the permeability is 0.1dracy;
S3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far away from the dispersion liquid is 400, the number of layers close to the dispersion liquid is 110, and vacuumizing from the lower surface side of the screen to form negative pressure until the water content is less than 120%, so as to form a primary finished product;
the steps of vacuum forming are as follows:
the first stage: the vacuum degree of the vacuum pumping is-45 Kpa,
and a second stage: the vacuumizing vacuum degree is-80 KPa;
s4: drying, namely shaping and drying the primary finished product for 8 hours at the temperature of 60 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the precision of the prepared deep filtration paperboard is 2 mu m, and the wet strength is 307Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm had a transmission of 6401 μg/cm 3 ；
Wherein:
the soap yellow dye liquor permeability from the area of one third of the thickness of the first side is 1129 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.3g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the Porosity was 38%;
the soap yellow dye liquor permeability from the second side area with the thickness of one third is 2023 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.36g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 20%.
Example 4: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 4wt% of coarse cellulose fiber slurry and 1wt% of fine cellulose fiber slurry;
s2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding filter aid diatomite and binder glyoxal-polyacrylamide, and stirring for 1h at 50 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 10wt% of coarse cellulose fibers, 30wt% of fine cellulose fibers, 55wt% of filter aid and 5wt% of adhesive;
the Canadian freeness of the crude cellulose fiber is 480ml, and the diameter is 700-800nm; the Canadian freeness of the fine cellulose fiber is 70ml, and the diameter is 200-300nm; the average particle diameter D50 of the filter aid is 4 mu m, and the permeability is 0.2dracy;
s3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far away from the dispersion liquid is 400, the number of layers close to the dispersion liquid is 110, and vacuumizing from the lower surface side of the screen to form negative pressure until the water content is less than 120%, so as to form a primary finished product;
The steps of vacuum forming are as follows:
the first stage: the vacuumizing vacuum degree is-50 Kpa,
and a second stage: the vacuumizing vacuum degree is-90 KPa;
s4: drying, namely shaping and drying the primary finished product for 4 hours at 160 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the precision of the prepared deep filtration paperboard is 1 mu m, and the wet strength is 283Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm had a penetration of 4780 μg/cm 3 ；
Wherein:
the soap yellow dye liquor permeability from the area with the thickness of one third of the first side surface is 911 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.33g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity is 35%;
the soap yellow dye liquor permeability from the area of one third of the thickness of the second side surface is 1263 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.36g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 16%.
Example 5: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 5wt% of coarse cellulose fiber slurry and 2wt% of fine cellulose fiber slurry;
S2: mixing, mixing the crude cellulose fiber slurry and the fine cellulose fiber slurry, adding filter aid diatomite and binder polyamide-epichlorohydrin resin, and stirring for 4 hours at 15 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 12t% of coarse cellulose fibers, 33t% of fine cellulose fibers, 50wt% of filter aid and 5wt% of adhesive;
the Canadian freeness of the crude cellulose fiber is 620ml, and the diameter is 20-30 mu m; the Canadian freeness of the fine cellulose fiber is 180ml, and the diameter is 60-80nm; the average particle diameter D50 of the filter aid is 20 mu m, and the permeability is 1dracy;
s3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far away from the dispersion liquid is 200 meshes, the number of layers close to the dispersion liquid is 60 meshes, and vacuumizing from the lower surface side of the screen to form negative pressure until the water content is less than 120%, so as to form a primary finished product;
the steps of vacuum forming are as follows:
the first stage: the vacuum degree of the vacuum pumping is-35 Kpa,
and a second stage: the vacuumizing vacuum degree is-70 KPa;
s4: drying, namely shaping and drying the primary finished product for 3 hours at the temperature of 200 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
The prepared deep filtration paperboard has the precision of 5 mu m and the wet strength of 258Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm has a penetration of 3680 μg/cm 3 ；
Wherein:
the soap yellow dye liquor permeability from the area of one third of the thickness of the first side is 487 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.27g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 46%;
the penetration of the yellow soap dye solution from the area with the thickness of one third of the second side surface is 1120 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.34g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 29%.
Example 6: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 5wt% of coarse cellulose fiber slurry and 2wt% of fine cellulose fiber slurry;
s2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding filter aid diatomite and binder melamine-formaldehyde resin, and stirring for 3.5 hours at 15 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 10wt% of coarse cellulose fibers, 26wt% of fine cellulose fibers, 60wt% of filter aid and 4wt% of adhesive;
The Canadian freeness of the crude cellulose fiber is 680ml, and the diameter is 25-30 mu m; the Canadian freeness of the fine cellulose fiber is 200ml, and the diameter is 65-90nm; the average particle diameter D50 of the filter aid is 25 mu m, and the permeability is 2dracy;
s3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far away from the dispersion liquid is 200 meshes, the number of layers close to the dispersion liquid is 60 meshes, and vacuumizing from the lower surface side of the screen to form negative pressure until the water content is less than 120%, so as to form a primary finished product;
the steps of vacuum forming are as follows:
the first stage: the vacuum degree of the vacuum pumping is-40 Kpa,
and a second stage: the vacuumizing vacuum degree is-75 KPa;
s4: drying, namely shaping and drying the primary finished product for 6 hours at 110 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the prepared deep filtration paperboard has the precision of 6 mu m and the wet strength of 274Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm has a penetration of 4033 μg/cm 3 ；
Wherein:
the soap yellow dye liquor permeability from the area with the thickness of one third of the first side surface is 529 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.26g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the Porosity is 49%;
the soap yellow dye liquor permeability from the second side area with the thickness of one third is 1233 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.33g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 31%.
Example 7: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 5wt% of coarse cellulose fiber slurry and 2wt% of fine cellulose fiber slurry;
s2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding filter aid diatomite, binder melamine-formaldehyde resin and charge additive triethylene diamine, and stirring for 2 hours at 25 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 15wt% of coarse cellulose fibers, 38wt% of fine cellulose fibers, 40wt% of filter aid, 3wt% of binder and 4wt% of charge additive;
the Canadian freeness of the crude cellulose fiber is 600ml, and the diameter is 30-35 mu m; the Canadian freeness of the fine cellulose fiber is 210ml, and the diameter is 55-70nm; the average particle diameter D50 of the filter aid is 22 mu m, and the permeability is 1.6dracy;
S3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far away from the dispersion liquid is 200 meshes, the number of layers close to the dispersion liquid is 60 meshes, and vacuumizing from the lower surface side of the screen to form negative pressure until the water content is less than 120%, so as to form a primary finished product;
the steps of vacuum forming are as follows:
the first stage: the vacuum degree of the vacuum pumping is-30 Kpa,
and a second stage: the vacuumizing vacuum degree is-70 KPa;
s4: drying, namely shaping and drying the primary finished product for 7 hours at the temperature of 80 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the prepared deep filtration paperboard has the precision of 6 mu m and the wet strength of 260Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm was permeable to 3420 μg/cm 3 ；
Wherein:
one third of the thickness from the first sideThe soap yellow dye liquor penetration of the area with the degree is 403 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.28g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity is 50%;
the soap yellow dye liquor permeability from the second side surface to the area with one third thickness is 1109 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.33g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 30%.
Example 8: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 4-6wt% of coarse cellulose fiber slurry and 1-3wt% of fine cellulose fiber slurry;
s2: mixing, mixing the crude cellulose fiber slurry and the fine cellulose fiber slurry, adding filter aid diatomite and binder polyamide-epichlorohydrin resin, and stirring for 2 hours at 30 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 12wt% of coarse cellulose fibers, 33wt% of fine cellulose fibers, 50wt% of filter aid and 5wt% of adhesive;
the Canadian freeness of the crude cellulose fiber is 1000ml, and the diameter is 20-30 mu m; the Canadian freeness of the fine cellulose fiber is 400ml, and the diameter is 60-80nm; the average particle diameter D50 of the filter aid is 20 mu m, and the permeability is 1dracy;
s3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layer, the number of layers far from the dispersion liquid is 60 meshes, the number of layers close to the dispersion liquid is 200 meshes, vacuumizing from the lower surface side of the screen to form negative pressure, and forming a primary finished product after the water content is less than 120 percent, wherein the vacuum degree is-70 KPa;
The steps of vacuum forming are as follows:
the first stage: the vacuum degree of the vacuum pumping is-35 Kpa,
and a second stage: the vacuumizing vacuum degree is-70 KPa;
s4: drying, namely shaping and drying the primary finished product for 5 hours at 130 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the prepared deep filtration paperboard has the precision of 8 mu m and the wet strength of 180Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye having a thickness of 0.35cm and a diameter of 4.7cm was 2612 μg/cm in transmission 3 ；
Wherein:
the soap yellow dye liquor permeability from the area with the thickness of one third of the first side surface is 420 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.28g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 52%;
the soap yellow dye liquor permeability from the area with the thickness of one third of the second side surface is 987 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.32g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 35%.
Example 9: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 5wt% of coarse cellulose fiber slurry and 2wt% of fine cellulose fiber slurry;
S2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding filter aid diatomite and binder glyoxal-polyacrylamide, and stirring for 1.5 hours at 35 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 12wt% of coarse cellulose fibers, 33wt% of fine cellulose fibers, 50wt% of filter aid and 5wt% of adhesive;
the Canadian freeness of the crude cellulose fiber is 300ml, and the diameter is 20-30 mu m; the Canadian freeness of the fine cellulose fiber is 35ml, and the diameter is 60-80nm; the average particle diameter D50 of the filter aid is 20 mu m, and the permeability is 1dracy;
s3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far from the dispersion liquid is 200 meshes, the number of layers close to the dispersion liquid is 60 meshes, vacuumizing from the lower surface side of the screen to form negative pressure, and forming a primary finished product after the water content is less than 120 percent, wherein the vacuum degree is-70 KPa;
the steps of vacuum forming are as follows:
the first stage: the vacuum degree of the vacuum pumping is-35 Kpa,
and a second stage: the vacuumizing vacuum degree is-70 KPa;
s4: drying, namely shaping and drying the primary finished product for 7 hours at the temperature of 80 ℃ until the water content is lower than 10%;
S5: punching, namely cutting the primary finished product to form a finished product;
the precision of the prepared deep filtration paperboard is 4 mu m, and the wet strength is 266Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm had a transmission of 3812 μg/cm 3 ；
Wherein:
the soap yellow dye liquor permeability from the area of one third of the thickness of the first side is 894 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.28g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity is 41%;
the soap yellow dye liquor permeability from the area with the thickness of one third of the second side surface is 1630 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.36g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 32%.
Example 10: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 6wt% of coarse cellulose fiber slurry and 3wt% of fine cellulose fiber slurry;
s2: mixing, mixing the coarse cellulose fiber slurry and the fine cellulose fiber slurry, adding filter aid diatomite and binder polyamide-epichlorohydrin resin, and stirring at 40 ℃ for 0.5h to form a dispersion liquid with uniform concentration;
Wherein the contents of the components are as follows: 18wt% of coarse cellulose fibers, 37wt% of fine cellulose fibers, 40wt% of filter aid and 5wt% of adhesive;
the Canadian freeness of the crude cellulose fiber is 750ml, and the diameter is 30-40 mu m; the Canadian freeness of the fine cellulose fiber is 310ml, and the diameter is 130-150nm; the average particle diameter D50 of the filter aid is 70 mu m, and the permeability is 5dracy;
s3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far away from the dispersion liquid is 100 meshes, the number of layers close to the dispersion liquid is 30 meshes, and vacuumizing from the lower surface side of the screen to form negative pressure until the water content is less than 120%, so as to form a primary finished product;
the steps of vacuum forming are as follows:
the first stage: the vacuum degree of the vacuum pumping is-15 Kpa,
and a second stage: the vacuumizing vacuum degree is-50 KPa;
s4: drying, namely shaping and drying the primary finished product for 3 hours at the temperature of 200 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the precision of the prepared deep filtration paperboard is 20 mu m, and the wet strength is 208Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm had a penetration of 522 μg/cm 3 ；
Wherein:
the soap yellow dye liquor permeability from the area of one third of the thickness of the first side is 144 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.21g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 58%;
the soap yellow dye liquor permeability from the area with the thickness of one third of the second side surface is 189 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.3g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 45%.
Example 11: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 6wt% of coarse cellulose fiber slurry and 3wt% of fine cellulose fiber slurry;
s2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding filter aid diatomite, binder glyoxal-polyacrylamide and charge additive chitosan, and stirring for 3 hours at 25 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 17wt% of coarse cellulose fibers, 32wt% of fine cellulose fibers, 45wt% of filter aid, 4wt% of binder and 2wt% of charge additive;
the Canadian freeness of the crude cellulose fiber is 780ml, and the diameter is 35-45 mu m; the Canadian freeness of the fine cellulose fiber is 280ml, and the diameter is 145-150nm; the average particle diameter D50 of the filter aid is 75 mu m, and the permeability is 5.3racy;
S3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far away from the dispersion liquid is 100 meshes, the number of layers close to the dispersion liquid is 30 meshes, and vacuumizing from the lower surface side of the screen to form negative pressure until the water content is less than 120%, so as to form a primary finished product;
the steps of vacuum forming are as follows:
the first stage: the vacuum degree of the vacuum pumping is-10 Kpa,
and a second stage: the vacuumizing vacuum degree is-50 KPa;
s4: drying, namely shaping and drying the primary finished product for 6 hours at 110 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the precision of the prepared deep filtration paperboard is 23 mu m, and the wet strength is 189Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm had a transmission of 807. Mu.g/cm 3 ；
Wherein:
the soap yellow dye liquor permeability of the area with the thickness of one third of the first side surface is 203 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.22g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the Porosity was 68%;
the penetration of the yellow soap dye solution from the area with the thickness of one third of the second side surface is 323 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.29g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 49%.
Example 12: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 6wt% of coarse cellulose fiber slurry and 3wt% of fine cellulose fiber slurry;
s2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding filter aid diatomite and binder melamine-formaldehyde resin, and stirring for 2.5 hours at 30 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 13wt% of coarse cellulose fibers, 19wt% of fine cellulose fibers, 65wt% of filter aid and 3wt% of adhesive;
the Canadian freeness of the crude cellulose fiber is 730ml, and the diameter is 40-45 mu m; the Canadian freeness of the fine cellulose fiber is 270ml, and the diameter is 120-130nm; the average particle diameter D50 of the filter aid is 66 mu m, and the permeability is 4dracy;
s3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layered, the number of layers far away from the dispersion liquid is 100 meshes, the number of layers close to the dispersion liquid is 30 meshes, and vacuumizing from the lower surface side of the screen to form negative pressure until the water content is less than 120%, so as to form a primary finished product;
The steps of vacuum forming are as follows:
the first stage: the vacuum degree of the vacuum pumping is-15 Kpa,
and a second stage: the vacuumizing vacuum degree is-55 KPa;
s4: drying, namely shaping and drying the primary finished product for 4 hours at 160 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the precision of the prepared deep filtration paperboard is 23 mu m, and the wet strength is 189Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; depth filtration cardboard soap Huang Ranye with a thickness of 0.35cm and a diameter of 4.7cm had a transmission of 509 μg/cm 3 ；
Wherein:
from the first sideOne third of the thickness of the dye liquor has a regional soap yellow dye liquor permeability of 140 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.22g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 66%;
the soap yellow dye liquor permeability from the area with the thickness of one third of the second side surface is 173 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.29g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 51%.
Example 13: a method of making a charged depth filtration paperboard comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain 6wt% of coarse cellulose fiber slurry and 3wt% of fine cellulose fiber slurry;
S2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding filter aid diatomite and binder melamine-formaldehyde resin, and stirring for 0.5h at 45 ℃ to form a dispersion liquid with uniform concentration;
wherein the contents of the components are as follows: 18wt% of coarse cellulose fibers, 37wt% of fine cellulose fibers, 40wt% of filter aid and 5wt% of adhesive;
the Canadian freeness of the crude cellulose fiber is 750ml, and the diameter is 30-40 mu m; the Canadian freeness of the fine cellulose fiber is 310ml, and the diameter is 130-150nm; the average particle diameter D50 of the filter aid is 70 mu m, and the permeability is 5dracy;
s3: forming, namely placing the stirred dispersion liquid on the upper surface of a screen, wherein the screen is double-layer, the number of layers far from the dispersion liquid is 100 meshes, the number of layers close to the dispersion liquid is 30 meshes, and vacuumizing from the lower surface side of the screen to form negative pressure, wherein the vacuum degree is-20 KPa, and the water content is 140%, so that a primary finished product is formed;
s4: drying, namely shaping and drying the primary finished product for 3 hours at 50 ℃ until the water content is lower than 10%;
s5: punching, namely cutting the primary finished product to form a finished product;
the precision of the prepared deep filtration paperboard is 28 mu m, and the wet strength is 133Kpa; comprises a paperboard body, a first filter and a second filter, wherein the paperboard body is provided with a first side surface for receiving liquid to be filtered and a second side surface for discharging permeate; thickness of 0.35 Depth filtration cardboard soap Huang Ranye having a cm, diameter of 4.7cm, has a penetration of 431 μg/cm 3 ；
Wherein:
the soap yellow dye liquor permeability from the area with the thickness of one third of the first side surface is 431 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.19g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 70%;
the soap yellow dye liquor permeability from the area with the thickness of one third of the second side surface is 127 mug/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The tightness is 0.24g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The porosity was 59%.
As can be seen from examples 1-3,5-7 and 10-12, the preparation method of the present invention can prepare depth filtration paper sheets having different precision and showing continuously rising gradient changes of tightness and charge amount from the first side to the second side; from example 4, it is clear that the gradient difference is relatively small when the fiber diameter is not within the limited range and the difference between the thick and thin fiber diameters is not obvious; as can be seen from example 8, the canadian freeness is too high, the fibrillation degree is too low, the exposed hydroxyl, carboxyl and other active groups are few, and the combination with the adhesive or the charge additive is difficult, so that the whole charge amount of the deep-layer filtering paperboard is low under the same charge addition amount, and meanwhile, the strength of the deep-layer filtering paperboard is insufficient; in example 13, the degree of vacuum during molding was two-stage molding, and the moisture content of the primary product was too high, and the drying temperature was low, resulting in too loose depth filtration paper board after final drying, and insufficient strength.
The four different precision depth filtration papers of examples 1, 5, 9 and 10 after pre-rinse were compared with commercially available depth filtration papers of similar precision and charge content, but with non-uniform charge content, by cell harvest liquid filtration as follows: the deep layer filters were obtained by stacking 15 layers of the same area, 4mm thick example and commercially available deep layer filtration cardboard, respectively, with a cell density of 25 x 10 6 cell/ml, cell viability 90%, turbidity 2376NTU 400L cell harvest at 130L/m 2 Filtering at a filtration flow rate of/hr, testing turbidity of filtrate and filtration pressure difference at the completion of filtration, wherein the pre-washing is performed at a flow rate of 10L/m 2 The pre-rinse was performed under water/min until no impurities were rinsed out, the results are shown in the following table.
| Project | Turbidity (NTU) | Differential pressure (bar) |
| Example 1 | 10-20 | 0.6 |
| Commercial 1 (X0 HC) | 15-25 | 0.8 |
| Example 5 | 50-80 | 1.1 |
| Example 9 | 50-80 | 1.4 |
| Commercial 2 (C0 HC) | 100-120 | 1.5 |
| Example 10 | 100-250 | 1 |
| Commercial 3 (D0 HC) | 200-400 | 1.2 |
As shown in the table above, after the deep filtration paper board filters the cell harvest liquid with the same volume, the invention has smaller turbidity and pressure difference compared with the commercial product, which indicates that the deep filtration paper board prepared by the invention has higher utilization rate.
While the preferred embodiments of the present invention have been described in detail, it will be appreciated that those skilled in the art, upon reading the above teachings, may make various changes and modifications to the invention. Such equivalents are also intended to fall within the scope of the claims appended hereto.
Claims (27)
1. A charged depth filtration paperboard comprising a paperboard body for the paperboard body comprising cellulosic fibers, a filter aid and a binder, the cellulosic fibers being bound by the binder and wrapped around the filter aid, characterized in that:
the paperboard body has a first side for receiving a liquid to be filtered, and
a second side surface for discharging the permeate,
the tightness of the first side surface to the second side surface shows continuously rising gradient change;
the paperboard body is positively charged, and the charge quantity is continuously increased from the first side surface to the second side surface in a gradient manner;
taking a cardboard body, constantly supplying soap Huang Ranye with concentration of 20ppm to the first side at a speed of 5ml/min, and when the transmittance of the permeation solution at 430nm is reduced to 95%, the permeation amount of soap Huang Ranye is 300-6500 μg/cm 3 ；
Wherein:
the transmission from the area of one third of the thickness of the first side is L1,
the transmission amount from the region of one third of the thickness of the second side surface is L2,
the ratio of L1 to L2 is 1:1.2-3.
2. The charged depth filter board of claim 1 wherein,
the transmission L1 of the region of one third of the thickness from the first side is 120-2200 mu g/cm 3 ，
The transmission L2 from the region of one third of the thickness of the second side is 150-4200 μg/cm 3 。
3. The charged depth filter board of claim 1 wherein,
the tightness of one third of the thickness from the first side is t1,
the tightness of one third of the thickness from the second side is t2,
the ratio of t1 to t2 is 1:1.1-1.7.
4. The charged depth filter board of claim 3,
the tightness of the paperboard body is 0.26-0.38g/cm 3 ；
Wherein:
the tightness t1 of one third of the thickness of the first side surface is 0.20-0.35g/cm 3 ；
The tightness t2 of one third of the thickness of the second side surface is 0.29 to 0.40g/cm 3 。
5. The charged depth filtration paperboard of claim 1 wherein in the paperboard body: the porosity of one third of the thickness from the first side is n1,
the porosity from the second side one third of the thickness is n2,
the n1 to n2 is 1.1-5:1.
6. The charged depth filtration paperboard of claim 5 wherein in the paperboard body: the porosity of one third of the thickness from the first side is 25-70%;
the porosity of one third of the thickness from the second side is 5-60%.
7. The charged depth filtration paperboard of claim 1 wherein the cellulosic fiber content of the paperboard body is 10-60wt%, the filter aid content is 30-80wt% and the binder content is 1-10wt%.
8. The charged depth filtration paperboard of claim 1 wherein the cellulose fibers comprise 20-40wt% coarse cellulose fibers and 60-80wt% fine cellulose fibers.
9. The charged depth filtration paperboard of claim 8 wherein the coarse cellulose fibers have a diameter of 1-50 μιη; the diameter of the fine cellulose fiber is 5-150nm.
10. The charged depth filtration paperboard of claim 8 wherein the coarse cellulose fibers have a canadian freeness of 450-800ml; the Canadian freeness of the fine cellulose fiber is 50-325ml.
11. The charged depth filtration paperboard of claim 1 wherein the filter aid comprises one or more of diatomaceous earth, silica, activated carbon.
12. The charged depth filtration paperboard of claim 11 wherein the filter aid has an average particle size D50 of from 0.05 to 80 μιη.
13. The method of making a charged depth filtration paperboard of claim 11 wherein the filter aid has a permeability of between 0.05 and 6 dracy.
14. The charged depth filtration paperboard of claim 1 wherein the binder comprises one or more of melamine-formaldehyde resin, polyamide-epichlorohydrin resin, glyoxal-polyacrylamide.
15. The charged depth filtration sheet of claim 1 wherein the sheet body further comprises a charge additive, the total charge additive and binder content of the sheet body being 1-10wt%.
16. The charged depth filtration paperboard of claim 15, wherein the charge additive comprises one or more of triethylenediamine, tetraethylenepentamine, chitosan.
17. The charged depth filtration paperboard of claim 1 wherein the wet strength of the paperboard body is between 150-400 Kpa.
18. The charged depth filtration paperboard of claim 1 wherein the paperboard body is provided with a thickness of between 1.5 and 6 mm.
19. A method of making a charged depth filtration board according to any one of claims 1 to 18, comprising the steps of:
s1: pulping, namely respectively selecting coarse cellulose fibers and fine cellulose fibers, mixing with water, and pulping to obtain coarse cellulose fiber slurry and fine cellulose fiber slurry;
s2: mixing, namely mixing the crude cellulose fiber slurry with the fine cellulose fiber slurry, adding a filter aid and a binder, and then stirring to form a dispersion liquid with uniform concentration;
S3: molding, namely placing the stirred dispersion liquid on the upper surface of a screen, and vacuumizing from the lower surface side of the screen to form negative pressure to form a primary finished product;
s4: drying, namely shaping and drying the primary finished product;
s5: punching, and cutting the primary product to form a finished product.
20. The method of making charged depth filtration paper board according to claim 19, wherein the concentration of coarse cellulose fiber slurry in step S1 is 4-6wt%; the fine cellulose fiber slurry has a concentration of 1 to 3wt%.
21. The method of making charged depth filtration paper board according to claim 19, wherein the agitation temperature during the agitation in step S2 is 15-50 ℃; the stirring time is 0.5h-4h.
22. The method of making charged depth filtration paper board according to claim 19, wherein a charge additive is further added in step S2.
23. The method of making charged depth filtration paper board according to claim 19, wherein said forming in step S3 is a two stage vacuum:
the first stage: the vacuumizing vacuum degree is-10 to-60 Kpa;
and a second stage: the vacuumizing vacuum degree is-50 to-100 KPa.
24. The method of making charged depth filtration paper board according to claim 19, wherein in step S3, vacuum is applied until the moisture content of the primary product is less than 100%.
25. The method of claim 19, wherein the screen in step S3 is a double layer, one layer has a mesh size of 20-120 mesh and the other layer has a mesh size of 80-500 mesh, and the mesh size of the layer adjacent to the dispersion is smaller than the mesh size of the layer distant from the dispersion.
26. The method of making charged depth filtration paper board according to claim 19, wherein said drying in step S4 is performed until the moisture content is below 10%.
27. The method of making charged depth filtration paper board according to claim 19 or 26, wherein the drying temperature is 60-200 ℃ and the drying time is 3-8 hours.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105492101A (en) * | 2013-08-30 | 2016-04-13 | Emd密理博公司 | High capacity composite depth filter media with low extractables |
| CN105770957A (en) * | 2014-12-22 | 2016-07-20 | 上海斯米克控股股份有限公司 | Air purifying compound and preparation method and application thereof |
| CN106687189A (en) * | 2014-08-15 | 2017-05-17 | 哈洛资源公司 | Granular filtration media mixture and uses in water purification |
| CN110585773A (en) * | 2018-06-13 | 2019-12-20 | 杭州科百特过滤器材有限公司 | Filtering paperboard and preparation method thereof |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105492101A (en) * | 2013-08-30 | 2016-04-13 | Emd密理博公司 | High capacity composite depth filter media with low extractables |
| CN106687189A (en) * | 2014-08-15 | 2017-05-17 | 哈洛资源公司 | Granular filtration media mixture and uses in water purification |
| CN105770957A (en) * | 2014-12-22 | 2016-07-20 | 上海斯米克控股股份有限公司 | Air purifying compound and preparation method and application thereof |
| CN110585773A (en) * | 2018-06-13 | 2019-12-20 | 杭州科百特过滤器材有限公司 | Filtering paperboard and preparation method thereof |
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