CN113144755A - Reusable mask filtering material and preparation method thereof - Google Patents
Reusable mask filtering material and preparation method thereof Download PDFInfo
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- CN113144755A CN113144755A CN202110465042.2A CN202110465042A CN113144755A CN 113144755 A CN113144755 A CN 113144755A CN 202110465042 A CN202110465042 A CN 202110465042A CN 113144755 A CN113144755 A CN 113144755A
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- 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
- B01D39/1607—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous
- B01D39/1623—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous of synthetic origin
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- 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
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
- B32B37/0076—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised in that the layers are not bonded on the totality of their surfaces
- B32B37/0084—Point bonding
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
- B32B37/06—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the heating method
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
- B32B37/10—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the pressing technique, e.g. using action of vacuum or fluid pressure
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
- B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
- B32B37/15—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
- B32B5/022—Non-woven fabric
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
- B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
- B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/02—Synthetic macromolecular fibres
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/02—Synthetic macromolecular fibres
- B32B2262/0223—Vinyl resin fibres
- B32B2262/0238—Vinyl halide, e.g. PVC, PVDC, PVF, PVDF
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/02—Synthetic macromolecular fibres
- B32B2262/0253—Polyolefin fibres
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/02—Synthetic macromolecular fibres
- B32B2262/0276—Polyester fibres
- B32B2262/0284—Polyethylene terephthalate [PET] or polybutylene terephthalate [PBT]
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/14—Mixture of at least two fibres made of different materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2571/00—Protective equipment
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- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
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- Nonwoven Fabrics (AREA)
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Abstract
The invention relates to a washable and washable reusable mask filtering material and a preparation method thereof. The filtering material is compounded by three layers which are mutually overlapped. The first layer is a receiving base material, the second layer is a nano fiber membrane which has a core filtering effect, and the third layer is a protective layer. And the second layer is formed by stacking a plurality of layers of nanofibers with gradient difference in fiber diameter, the thin nanofibers have a core filtering function, and the thicker nanofibers have a filtering effect and simultaneously protect the thin nanofiber membrane. The composite filter material provided by the invention completely intercepts particulate matters by virtue of the action of materials, does not need electret treatment, can tolerate the conventional washing and disinfection processes, does not have obvious performance reduction after washing and disinfection, has the resistance of 15-200Pa after washing and disinfection for many times, has the filtering effect of 30-99.99% on NaCl aerosol with the diameter of 0.3 micrometer, and can be used for manufacturing washing-resistant and disinfection-resistant reusable masks.
Description
Technical Field
The invention relates to the field of filtering materials for masks, in particular to a washable and washable reusable filtering material for masks and a preparation method thereof.
Background
The reusable mask has extremely important significance for solving the early 'flustered mask' of epidemic disease, can save resources and avoid the pollution of a large amount of discarded used masks to the environment. The mask can be repeatedly used in various ways, such as ultraviolet disinfection, medical alcohol disinfection, high-temperature steam disinfection, water washing and the like.
But traditional melt-blown cloth filter material mainly relies on electrostatic action to intercept the particulate matter, and static can be neutralized after washing and medical alcohol disinfection, and filtration efficiency descends by a wide margin, is difficult to prepare the repeatable gauze mask of high performance's resistant washing. The filtering material based on the nanofiber membrane, such as the nanofiber membrane prepared by electrostatic spinning, has the advantages of small fiber diameter, large specific surface area and high porosity, and is an ideal material for preparing the high-efficiency low-resistance filtering material. Compared with melt-blown cloth, the filter efficiency is higher, and the KN 95-level filter effect can be realized without static electricity by physical interception.
However, since the nanofiber membrane is very thin and has low mechanical strength, it cannot normally withstand external force during washing, and is broken, resulting in a great reduction in filtration effect. For example, patent publication CN106237717B reports a filter material of nonwoven/nanofiber/nonwoven, which has excellent filtering effect, but because the fiber diameter of nonwoven is usually 5-20 microns thick and the diameter of nanofiber membrane is usually 50-500nm, two layers of nonwoven cannot achieve effective protection of nanofiber membrane due to too large difference of fiber diameter, and the composite before three layers is not tight enough, so that breakage easily occurs during washing and disinfection, and the filtering efficiency is greatly reduced.
The current patents can not effectively solve the problem that the nanofiber membrane can not resist washing and disinfection for many times.
Disclosure of Invention
Technical problem
In order to solve the problems of the prior art, the invention aims to provide a nanofiber membrane composite filter material which is efficient, low in resistance and resistant to multiple washing and disinfection and a preparation method thereof. The method has simple process, easy mass production, easy regulation and control of the performance of the filtering material, no damage after multiple washing and disinfection, and stable performance, and can be used for preparing reusable plane and three-dimensional protective masks.
Technical scheme
For the above purpose of the present invention, the present invention provides in a first aspect a gradient structure filter material resistant to washing and sterilization, characterized in that: the filtering material at least comprises three layers which are mutually overlapped and compounded, namely a receiving base material A, a nanofiber membrane core filtering layer B and a micron protection primary filtering layer C:
the nanofiber membrane core filtering layer B is composed of a plurality of layers of nanofiber membranes with fiber diameter gradients, and the fiber diameters of the nanofiber membranes in the plurality of layers gradually decrease from layers on two sides to layers in the middle in sequence.
In some embodiments of the invention, the multilayer nanofiber membrane consists of 3 layers of nanofiber membrane, wherein the thicker fibers of nanofibers B1 and B3 sandwich the thin nanofiber membrane B2.
In some embodiments of the present invention, the core filtration layer B is made by electrospinning and solution jet spinning, and the fiber diameter is 20-1000nm, wherein the fiber diameter of the B2 layer is 20-500nm, the grammage is 0.1-10g/m2, the fiber diameter of the B1 and B3 layers is 200-1000nm, and the grammage is 0.2-20g/m 2.
In some embodiments of the invention, the fiber diameter of the receiving substrate a and the protective layer C > B1 and the fiber diameter of the B3 layer > B2.
In some embodiments of the present invention, the core filter layer and the layers B1, B2 and B3 may be made of the same material or different materials, and the materials are selected from polyacrylonitrile PAN, nylon-6 PA6, nylon-66 PA66, polyvinylidene fluoride PVDF, cellulose acetate CA, polyether sulfone PES, elastic polyurethane TPU, polylactic acid PLA, polyvinyl alcohol PVA, polyacrylic acid PAA, and polyimide PI.
In some embodiments of the present invention, the receiving substrate and the micro-protection primary filter layer are composed of micro-fibers, each of which is selected from melt-blown nonwoven fabric, spun-bonded nonwoven fabric, needle-punched nonwoven fabric, spunlaced nonwoven fabric, hot-rolled nonwoven fabric, hot-air cotton, knitted fabric, and woven fabric, and the receiving substrate and the micro-protection primary filter layer are made of materials selected from polypropylene PP, polyethylene PE, polyester PET, PE/PP or PE/PET ES fibers, polyamide PA, polyurethane TPU, and ethylene-vinyl acetate copolymer EVA, and have a grammage of 10-200g/m 2.
In some embodiments of the present invention, the three layers of the receiving substrate (a), the nanofiber membrane core filter layer (B), and the micron protective primary filter layer (C) stacked on each other are stacked together by ultrasonic welding, high-temperature hot press bonding, or first press bonding and then ultrasonic welding.
In some embodiments of the present invention, the filtration efficiency of the filter material for 0.3 μm NaCl particles after 30 washes and sterilizations is 30% to 99.99% at a filtration resistance of 30 to 150 Pa.
In some embodiments of the invention, the sterilization comprises medical alcohol sterilization, boiling sterilization, hot water sterilization, oven sterilization.
In a second aspect, the present invention provides a method of making a wash and sterilize durable gradient structure filter material according to the first aspect of the invention, comprising:
step 1: dissolving the material powder of the nanofiber membrane B1 in a solvent to prepare a B1 solution;
step 2: dissolving the material powder of the nanofiber membrane B2 in a solvent to prepare a B2 solution, and dissolving the material powder of the nanofiber membrane B3 in the solvent to prepare a B3 solution;
and step 3: electrostatic spinning is carried out on the receiving substrate A by using the B1 solution as a spinning solution to obtain a nanofiber membrane B1;
and 4, step 4: using the B2 solution as a spinning solution, and continuing electrostatic spinning on the nanofiber membrane B1 obtained in the step 3 to obtain a nanofiber membrane B2;
and 5: using the B3 solution as a spinning solution, and continuing electrostatic spinning on the nanofiber membrane B2 obtained in the step 4 to obtain a nanofiber membrane B3;
step 6: and (3) removing the prepared receiving substrate A/nanofiber membrane B1/nanofiber membrane B2/nanofiber membrane B3 from a roller, covering a micron protective primary filter layer C on the roller, and pressing at high temperature to obtain the composite mask filter material of the tightly combined receiving substrate A/nanofiber membrane B1/nanofiber membrane B2/nanofiber membrane B3/micron protective primary filter layer C.
In some embodiments of the second mode of the present invention, the material of the nanofiber membrane B1 used in step 1 is PVDF nanofiber (molecular weight 15 ten thousand), and the solvent is N, N-Dimethylformamide (DMF) and acetone in a mass ratio of 6: 4 in a mixed solvent; or PES nanofibers (molecular weight 8 ten thousand) in N, N-Dimethylformamide (DMF).
In some embodiments of the second mode of the present invention, the material of the nanofiber membrane B2 used in step 2 is PAN nanofibers (molecular weight 12 ten thousand), and the solvent is DMF solvent; alternatively, PVDF nanofibers (molecular weight 15 ten thousand) with solvent DMF solvent; alternatively, PAN nanofibers (molecular weight 15 ten thousand) and the solvent was DMF solvent. The nanofiber membrane B3 is made of PVDF nanofiber (molecular weight is 15 ten thousand), and the solvent is N, N-Dimethylformamide (DMF) and acetone in a mass ratio of 6: 4 in a mixed solvent; or PES nanofibers (molecular weight 8 ten thousand) in N, N-Dimethylformamide (DMF).
In some embodiments of the second mode of the present invention, the receiving substrate A used in step 2 is 25g/m2Pp of spunbonded nonwoven, 25g/m2Spun-bonded non-woven fabric made of PET material.
In some embodiments of the second mode of the present invention, the average diameters of the nanofibers in the obtained nanofiber membrane B1, the obtained nanofiber membrane B2 and the obtained nanofiber membrane B3 in steps 3, 4 and 5 are 400-; or 400-600nm, 200-300nm and 400-600 nm.
In some embodiments of the second mode of the present invention, the micron protective primary filter layer C used in step 6 is 15g/m2PE/PP hot air cotton, 25g/m2PP material spunbonded nonwoven.
Has the advantages that:
according to the invention, through the double-sandwich structure, the nanofiber membrane is subjected to coarse protection by utilizing two micron-level fiber layers, and the nanofiber membrane and the micron-level fiber membrane are tightly combined together in an ultrasonic spot welding or high-temperature hot pressing mode, so that the fiber is prevented from being damaged due to integral movement caused by stress in the washing or disinfection process. Meanwhile, the nanofiber membrane is of a sandwich structure, the thin nanofiber layer has a fine filtering effect, the thick nanofiber layer also has a good filtering effect, and the thick nanofiber layer is used as a protective layer or a sacrificial layer to perform a finer protective effect on the thin nanofiber layer.
Drawings
The present invention may be described in more detail, but is not limited to, in conjunction with the following figures, wherein:
FIG. 1 is a schematic cross-sectional view of a filter material of the present invention, wherein the filled circles in each layer represent the cross-section of each fiber;
fig. 2 is a photomicrograph of only one layer of fine PAN nanofiber membrane after washing, showing that significant breakage occurred and filtration efficiency dropped from 98% to 64%;
FIG. 3 is a photomicrograph of the crude PVDF/fine PAN/crude PVDF sandwich of the invention after washing showing no significant breakage and still having a filtration efficiency of > 95%.
Detailed Description
While the invention is susceptible to various modifications and alternative forms, specific examples will be described and illustrated in detail below. It should be understood, however, that these are not intended to limit the invention to the particular disclosure, and that the invention includes all modifications, equivalents, and alternatives thereof without departing from the spirit and technical scope of the invention.
Hereinafter, a filter material for a mask according to an embodiment of the present invention will be explained in more detail.
In the filter material for a mask, the smaller the fiber diameter, the better the filtration effect, and the lower the grammage of the nanofiber membrane is, the lower the strength of the fiber membrane is, and the more easily the fiber membrane is broken during washing, in the same filtration resistance. The thicker the fiber diameter of the nanofibers, the higher the strength, but the lower the filtration effect. The micron-sized fiber layer has high mechanical strength but has little filtering effect on particles with a particle size of less than 1 μm. According to the invention, through the double-sandwich structure, the nanofiber membrane is subjected to coarse protection by utilizing two micron-level fiber layers, and the nanofiber membrane and the micron-level fiber membrane are tightly combined together in an ultrasonic spot welding or high-temperature hot pressing mode, so that the fiber is prevented from being damaged due to integral movement caused by stress in the washing or disinfection process. Meanwhile, the nanofiber membrane is of a sandwich structure, the thin nanofiber layer has a fine filtering effect, the thick nanofiber layer also has a good filtering effect, and the thick nanofiber layer is used as a protective layer or a sacrificial layer to perform a finer protective effect on the thin nanofiber layer.
In an embodiment of the invention, there is provided a gradient structure filter material that is wash and sterilization resistant, characterized in that: the filtering material at least comprises three layers which are mutually overlapped and compounded, namely a receiving base material (A), a nanofiber membrane core filtering layer (B) and a micron protection primary filtering layer (C):
wherein the nanofibrous membrane core filter layer (B) in turn consists of a plurality of (at least 3) nanofibrous membranes with a gradient of fibre diameter, in case for example consisting of 3 nanofibrous membranes, the thicker fibres of nanofibres B1 and B3 sandwich the thin nanofibrous membrane B2, further fine protection.
In the embodiment of the invention, the core filter layer B is manufactured by electrostatic spinning (electrospinning) and solution jet spinning (blow spinning) processes, the fiber diameter is 20-1000nm, the fiber diameter of the B2 layer is 20-500nm, and the gram weight is 0.1-10g/m2The fiber diameter of the B1 and B3 layers is 200-1000nm, and the gram weight is 0.2-20g/m2。
In an embodiment of the invention, the fiber diameter of the receiving substrate a and the protective layer C > B1 and the fiber diameter of the B3 layer > B2.
In the embodiment of the invention, the core filter layers B1, B2 and B3 may be made of the same material or different materials. The material includes but is not limited to polyacrylonitrile PAN, nylon-6 PA6, nylon-66 PA66, polyvinylidene fluoride PVDF, cellulose acetate CA, polyether sulfone PES, elastic polyurethane TPU, polylactic acid PLA, polyvinyl alcohol PVA, polyacrylic acid PAA, polyimide PI and other materials.
In an embodiment of the present invention, the receiving substrate and the protective layer are composed of micro fibers, preferably melt-blown nonwoven fabric, spun-bonded nonwoven fabric, needle-punched nonwoven fabric, spunlaced nonwoven fabric, hot-rolled nonwoven fabric, hot-air cotton, knitted fabric, woven fabric, and the like, the material may be polypropylene PP, polyethylene PE, polyester PET, PE/PP or PE/PET ES fiber, polyamide PA, polyurethane TPU, ethylene-vinyl acetate copolymer EVA, and the like, and the gram weight is 10-200g/m2。
In some embodiments of the invention, the receiving substrate A is 25g/m2The PP material spun-bonded non-woven fabric has a protective layer C of 15g/m2PE/PP hot-air cotton, the nanofiber membrane B1 is PVDF nanofiber with the average diameter of 400-600nm, NaThe nanofiber membrane B2 is PAN nanofiber with the average diameter of 150-250nm, and the nanofiber membrane B3 is PVDF nanofiber with the average diameter of 400-600 nm.
In some embodiments of the invention, the receiving substrate A is 25g/m2The protective layer C of the spun-bonded non-woven fabric made of PET material is 25g/m2The PP spun-bonded non-woven fabric comprises a PP material, a nanofiber membrane B1 is PVDF nanofiber with the average diameter of 400-600nm, a nanofiber membrane B2 is PVDF nanofiber with the average diameter of 200-300nm, and a nanofiber membrane B3 is PVDF nanofiber with the average diameter of 400-600 nm.
In some embodiments of the invention, the receiving substrate A is 25g/m2The PP material spun-bonded non-woven fabric has a protective layer C of 15g/m2PE/PP hot-air cotton, the nanofiber membrane B1 is PES nanofiber with the average diameter of 400-600nm, the nanofiber membrane B2 is PAN nanofiber with the average diameter of 150-250nm, and the nanofiber membrane B3 is PES nanofiber with the average diameter of 400-600 nm.
In an embodiment of the present invention, the three layers stacked on each other are stacked together by ultrasonic welding, high-temperature thermal compression, or ultrasonic welding after lamination.
In the embodiment of the present invention that is combined by ultrasonic welding, the ultrasonic welding can be performed by an ultrasonic welding apparatus.
In the embodiment of the invention which adopts high-temperature hot pressing for compounding, the high-temperature hot pressing can be completed by adopting instruments such as a high-temperature ironing machine, and the temperature of the high-temperature hot pressing can be 50-150 ℃, and is preferably 70-100 ℃; the time of high-temperature hot pressing can be 30s-30min, preferably 1-5 min.
In the embodiment of the present invention, in which the composite material is formed by pressing and then ultrasonic welding, the ultrasonic welding may be performed by an ultrasonic welding apparatus, and the power and time of the ultrasonic welding may be determined according to the properties of the composite material.
In the embodiment of the invention, after the filtering material resistant to water washing is subjected to conventional washing and disinfection for multiple times (including modes of medical alcohol disinfection, boiling disinfection, hot water disinfection, oven disinfection and the like), the filtering performance of the filtering material is only slightly reduced, and when the filtering resistance is 30-150Pa after the filtering material is subjected to washing and disinfection for 30 times, the filtering efficiency of the filtering material on NaCl particles with the particle size of 0.3 mu m is 30% -99.99%.
Examples
The following non-limiting examples are provided. The following percentages are by weight, if not otherwise stated.
Example 1:
receiving a substrate A: 25g/m2PP material spunbonded non-woven fabric
Protective layer C: 15g/m2PE/PP hot air cotton
Nanofiber membrane B1 PVDF nanofiber (molecular weight 15 ten thousand)
Nanofiber membrane B2 PAN nanofiber (molecular weight 12 ten thousand)
Nanofiber membrane B3 PVDF nanofiber (molecular weight 15 ten thousand)
Step 1: dissolving PVDF powder in N, N-Dimethylformamide (DMF) and acetone in a mass ratio of 6: 4, magnetically stirring in a water bath of 50 ℃ for 12 to 24 hours to prepare a 12.5 wt% PVDF solution.
Step 2: dissolving PAN powder in DMF solvent, and magnetically stirring in 70 deg.C water bath for 12-24 hr to obtain 14.5 wt% PAN solution.
And step 3: mixing 25g/m2The pp spunbonded nonwoven fabric is rolled on a roller to be used as a receiving base material, PVDF solution is selected as spinning solution, the spinning voltage is 10KV, the rotating speed of the roller is 100r/min, the receiving distance between a spray head and the roller is 15cm, the transverse moving speed of the spray head is 50cm/min, the spinning speed is 0.4ml/h, the environmental temperature is 25 ℃, the humidity is 30-40%, the spinning time is 60min, and the PVDF nano-fiber membrane with the average diameter of 400-600nm is obtained.
And 4, step 4: and (3) selecting a PAN solution as a spinning solution, continuously spinning on the PVDF nano-fiber membrane obtained in the step (3), wherein the spinning voltage is 12KV, the rotating speed of a roller is 100r/min, the receiving distance between a spray head and the roller is 15cm, the transverse moving speed of the spray head is 50cm/min, the spinning speed is 0.4ml/h, the environmental temperature is 25 ℃, the humidity is 30-40%, and the spinning time is 90min, so that the PAN nano-fiber membrane with the average diameter of 150 plus 250nm is obtained.
And 5: and (3) adopting a PVDF solution as a spinning solution, continuously spinning on the PAN nanofiber membrane obtained in the step (4), wherein the spinning voltage is 12KV, the rotating speed of a roller is 100r/min, the receiving distance between a spray head and the roller is 15cm, the transverse moving speed of the spray head is 50cm/min, the spinning speed is 0.4ml/h, the environmental temperature is 25 ℃, the humidity is 30-40%, and the spinning time is 60min, so that the PAN nanofiber membrane with the average diameter of 400-600nm is obtained.
Step 6: the prepared spun-bonded non-woven fabric/PVDF nano fiber/PAN nano fiber/PVDF nano fiber are taken off from the roller, and a layer of 15g/m is covered on the roller2The hot air cotton is pressed at the high temperature of 140 ℃ to obtain the spunbonded non-woven fabric/coarse PVDF nano fiber/fine PAN nano fiber/coarse PVDF nano fiber/hot air cotton composite mask filtering material which is tightly compounded together.
And 7: after the composite mask filtering material is washed for 30 times, the filtering resistance is less than 65Pa, the filtering efficiency to 300nm sodium chloride particles is more than 95%, and the composite mask filtering material can be used for manufacturing reusable KN90 or KN95 protective masks.
Referring to fig. 2 and 3, in fig. 2, only one fine PAN nanofiber membrane was significantly damaged after washing, and the filtration efficiency decreased from 98% to 64%, but in fig. 3 the crude PVDF/fine PAN/crude PVDF sandwich structure of the present invention was cleaned without significant damage, and the filtration efficiency remained > 95%. The filtration efficiencies of the two membranes before and after washing are shown in table 1 below.
TABLE 1 filtration efficiency before and after washing
| Kind of fibrous membrane | Filtration efficiency before washing | Filtration efficiency after washing |
| Single-layer PAN nanofiber membrane | 98.908％ | 64.051％ |
| Crude PVDF/Fine PAN/crude PVDF | 98.772％ | 96.940％ |
Example 2:
receiving a substrate A: 25g/m2Spun-bonded non-woven fabric made of PET material
Protective layer C: 25g/m2Spun-bonded non-woven fabric made of PP (polypropylene) material
Nanofiber membrane B1 PVDF nanofiber (molecular weight 15 ten thousand)
Nanofiber membrane B2 PVDF nanofiber (molecular weight 15 ten thousand)
Nanofiber membrane B3 PVDF nanofiber (molecular weight 15 ten thousand)
Step 1: dissolving PVDF powder in N, N-Dimethylformamide (DMF) and acetone in a mass ratio of 6: 4, and magnetically stirring the mixture in a water bath of 50 ℃ for 12 to 24 hours to prepare a 12.5 wt% PVDF solution (PVDF-1 solution).
Step 2: PVDF powder was dissolved in DMF solvent, and magnetically stirred in a 70 ℃ water bath for 12 to 24 hours to prepare a 12.5 wt% PVDF solution (PVDF-2 solution).
And step 3: winding 25g/m2 PET spunbonded nonwoven fabric on a roller as a receiving base material, selecting PVDF-1 solution as spinning solution, wherein the spinning voltage is 10KV, the rotating speed of the roller is 100r/min, the receiving distance between a spray head and the roller is 15cm, the transverse moving speed of the spray head is 50cm/min, the spinning speed is 0.4ml/h, the environmental temperature is 25 ℃, the humidity is 30-40%, and the spinning time is 30min, thus obtaining the PVDF nanofiber membrane with the average diameter of 400-600 nm.
And 4, step 4: and (3) selecting a PVDF-2 solution as a spinning solution, continuously spinning on the PVDF nanofiber membrane obtained in the step (3), wherein the spinning voltage is 10KV, the rotating speed of a roller is 100r/min, the receiving distance between a spray head and the roller is 15cm, the transverse moving speed of the spray head is 50cm/min, the spinning speed is 0.2ml/h, the environmental temperature is 25 ℃, the humidity is 30-40%, and the spinning time is 15min, so that the PVDF nanofiber membrane with the average diameter of 200-300nm is obtained.
And 5: and (3) selecting a PVDF-1 solution as a spinning solution, continuously spinning on the PAN nanofiber membrane obtained in the step (4), wherein the spinning voltage is 12KV, the rotating speed of a roller is 100r/min, the receiving distance between a spray head and the roller is 15cm, the transverse moving speed of the spray head is 50cm/min, the spinning speed is 0.4ml/h, the environmental temperature is 25 ℃, the humidity is 30-40%, and the spinning time is 30min, so that the PVDF nanofiber membrane with the average diameter of 400-600nm is obtained.
Step 6: the prepared spun-bonded non-woven fabric/coarse PVDF nano fiber/fine PVDF nano fiber/coarse PVDF nano fiber are uncovered from the roller, and a layer of 25g/m is covered on the roller2The PP spunbonded non-woven fabric is pre-laminated for 2 minutes at 70 ℃ so that the filter material is slightly compounded together, and then the filter material is further compounded through ultrasonic spot welding to obtain the spunbonded non-woven fabric/coarse PVDF nano fiber/fine PVDF nano fiber/coarse PVDF nano fiber/spunbonded non-woven fabric composite mask filter material with good compounding.
And 7: after the composite mask filtering material is washed for 30 times, the filtering resistance is less than 35Pa, the filtering efficiency to 300nm sodium chloride particles is more than 70%, and the composite mask filtering material can be used for manufacturing reusable plane masks.
Example 3:
receiving a substrate A: 25g/m2PP material spunbonded non-woven fabric
Protective layer C: 15g/m2PE/PP hot air cotton
Nanofiber membrane B1 PES nanofiber (molecular weight 8 ten thousand)
Nanofiber membrane B2 PAN nanofiber (molecular weight 15 ten thousand)
Nanofiber membrane B3 PES nanofiber (molecular weight 8 ten thousand)
Step 1: PES powder was dissolved in N, N-Dimethylformamide (DMF) solvent, and magnetically stirred in a 50 ℃ water bath for 12 to 24 hours to prepare an 18 wt% PES solution.
Step 2: dissolving PAN powder in DMF solvent, and magnetically stirring in 70 deg.C water bath for 12-24 hr to obtain 14.5 wt% PAN solution.
And step 3: winding 25g/m2 pp spunbonded nonwoven fabric on a roller as a receiving base material, selecting PES solution as spinning solution, spinning at 8KV, rotating speed of the roller of 100r/min, receiving distance between a nozzle and the roller of 15cm, transverse moving speed of the nozzle of 50cm/min, spinning speed of 0.4ml/h, ambient temperature of 25 ℃, humidity of 30-40% and spinning time of 60min, and obtaining the PES nanofiber membrane with average diameter of 400-600 nm.
And 4, step 4: and (3) selecting a PAN solution as a spinning solution, continuously spinning on the PES nanofiber membrane obtained in the step (3), wherein the spinning voltage is 12KV, the rotating speed of a roller is 100r/min, the receiving distance between a spray head and the roller is 15cm, the transverse moving speed of the spray head is 50cm/min, the spinning speed is 0.4ml/h, the environmental temperature is 25 ℃, the humidity is 30-40%, and the spinning time is 80min, so that the PAN nanofiber membrane with the average diameter of 150 plus 250nm is obtained.
And 5: and (3) selecting a PES solution as a spinning solution, continuously spinning on the PAN nanofiber membrane obtained in the step (4), wherein the spinning voltage is 8KV, the rotating speed of the roller is 100r/min, the receiving distance between the spray head and the roller is 15cm, the transverse moving speed of the spray head is 50cm/min, the spinning speed is 0.4ml/h, the environmental temperature is 25 ℃, the humidity is 30-40%, and the spinning time is 60min, so that the PES nanofiber membrane with the average diameter of 400 plus 600nm is obtained.
Step 6: the prepared spun-bonded non-woven fabric/PES nano fiber/PAN nano fiber/PES nano fiber is taken off from a roller, and a layer of 15g/m is covered on the spun-bonded non-woven fabric/PES nano fiber2The hot air cotton is pressed at the high temperature of 140 ℃ to obtain the spunbonded nonwoven fabric/coarse PES nanofiber/fine PAN nanofiber/coarse PES nanofiber/hot air cotton composite mask filter material which is tightly compounded together.
And 7: after the composite mask filtering material is washed for 30 times, the filtering resistance is less than 70Pa, the filtering efficiency to 300nm sodium chloride particles is more than 90%, and the composite mask filtering material can be used for manufacturing a reusable KN90 protective mask.
Claims (10)
1. A washing and disinfection resistant gradient structure filter material is characterized in that: the filtering material at least comprises three layers which are mutually overlapped and compounded, namely a receiving base material A, a nanofiber membrane core filtering layer B and a micron protection primary filtering layer C:
the nanofiber membrane core filtering layer B is composed of a plurality of layers of nanofiber membranes with fiber diameter gradients, and the fiber diameters of the nanofiber membranes in the plurality of layers gradually decrease from layers on two sides to layers in the middle in sequence.
2. A wash and sanitization resistant gradient structure filter material as in claim 1, wherein: the multilayer nanofiber membrane consisted of 3 layers of nanofiber membrane, with thicker fibers nanofibers B1 and B3 sandwiching the thin nanofiber membrane B2.
3. A wash and sanitization resistant gradient structure filter material as in claim 2, wherein: the core filter layer B is prepared by electrostatic spinning (electrospinning) and solution jet spinning (blow spinning), the fiber diameter is 20-1000nm, the fiber diameter of the B2 layer is 20-500nm, and the gram weight is 0.1-10g/m2The fiber diameter of the B1 and B3 layers is 200-1000nm, and the gram weight is 0.2-20g/m2。
4. A wash and sanitization resistant gradient structure filter material as in claim 2, wherein: the fiber diameter of the receiving substrate a and the protective layer C > B1 and the fiber diameter of the B3 layer > B2 layer.
5. A wash and sanitization resistant gradient structure filter material as in claim 2, wherein: the core filter layer, the layers B1, B2 and B3 can be made of the same material or different materials, and the materials are respectively selected from Polyacrylonitrile (PAN), nylon-6 PA6, nylon-66 PA66, polyvinylidene fluoride (PVDF), Cellulose Acetate (CA), polyether sulfone (PES), elastic polyurethane (TPU), polylactic acid (PLA), polyvinyl alcohol (PVA), polyacrylic acid (PAA) and Polyimide (PI).
6. A wash and sanitization resistant gradient structure filter material as in claim 1, wherein: the receiving substrate and the primary micron-sized protective filter layer are composed of micron fibers, and are respectively selected from melt-blown non-woven fabric, spun-bonded non-woven fabric, needle-punched non-woven fabric,The receiving substrate and the micron protection primary filter layer are respectively made of polypropylene PP, polyethylene PE, polyester PET, PE/PP or PE/PET ES fibers, polyamide PA, polyurethane TPU and ethylene-vinyl acetate copolymer EVA with the gram weight of 10-200g/m2。
7. A wash and sanitization resistant gradient structure filter material as in claim 1, wherein: the three layers of the receiving base material (A), the nanofiber membrane core filter layer (B) and the micron protective primary filter layer (C) which are mutually overlapped are combined together in an ultrasonic welding mode, a high-temperature hot pressing mode or a mode of firstly pressing and then ultrasonic welding.
8. A wash and sanitization resistant gradient structure filter material as in claim 1, wherein: after the filter material is washed and disinfected for 30 times, the filter efficiency of the filter material to NaCl particles with the particle size of 0.3 mu m is 30-99.99% when the filter resistance is 30-150 Pa.
9. A wash and sanitization resistant gradient structure filter material as in claim 8, wherein: the disinfection comprises medical alcohol disinfection, boiling disinfection, hot water disinfection and oven disinfection.
10. A method of making a wash and sterilize durable gradient structure filter material of any of claims 2-9 comprising:
step 1: dissolving the material powder of the nanofiber membrane B1 in a solvent to prepare a B1 solution;
step 2: dissolving the material powder of the nanofiber membrane B2 in a solvent to prepare a B2 solution, and dissolving the material powder of the nanofiber membrane B3 in the solvent to prepare a B3 solution;
and step 3: electrostatic spinning is carried out on the receiving substrate A by using the B1 solution as a spinning solution to obtain a nanofiber membrane B1;
and 4, step 4: using the B2 solution as a spinning solution, and continuing electrostatic spinning on the nanofiber membrane B1 obtained in the step 3 to obtain a nanofiber membrane B2;
and 5: using the B3 solution as a spinning solution, and continuing electrostatic spinning on the nanofiber membrane B2 obtained in the step 4 to obtain a nanofiber membrane B3;
step 6: and (3) removing the prepared receiving substrate A/nanofiber membrane B1/nanofiber membrane B2/nanofiber membrane B3 from a roller, covering a micron protective primary filter layer C on the roller, and pressing at high temperature to obtain the composite mask filter material of the tightly combined receiving substrate A/nanofiber membrane B1/nanofiber membrane B2/nanofiber membrane B3/micron protective primary filter layer C.
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| CN113996118A (en) * | 2021-11-29 | 2022-02-01 | 闽江学院 | Composite filtering material with gradient structure and preparation method thereof |
| CN114703559A (en) * | 2022-04-22 | 2022-07-05 | 上海水星家用纺织品股份有限公司 | Preparation method and application of nanofiber spinning solution |
| CN114934356A (en) * | 2022-06-07 | 2022-08-23 | 赵辛欣 | Degradable nanofiber mask filter element with reproducible antibacterial performance and preparation method thereof |
| CN115157788A (en) * | 2022-06-30 | 2022-10-11 | 山东黄河三角洲纺织科技研究院有限公司 | One-way moisture-conducting fabric with protection function and preparation method and application thereof |
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