CN112746391A

CN112746391A - Self-charging self-cleaning melt-blown non-woven fabric and mask

Info

Publication number: CN112746391A
Application number: CN202011596148.8A
Authority: CN
Inventors: 吴晓彪; 宋特; 林东山; 林一速
Original assignee: Hengan Jinjiang Household Products Co ltd; Hengan Fujian Holding Group Co Ltd
Current assignee: Hengan Jinjiang Household Products Co ltd; Hengan Fujian Holding Group Co Ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-05-04
Anticipated expiration: 2040-12-29
Also published as: CN112746391B

Abstract

The invention discloses a self-charging self-cleaning melt-blown non-woven fabric, wherein melt-blown fibers of the melt-blown non-woven fabric contain permanent electrets and piezoelectric materials. The processing method of the melt-blown non-woven fabric comprises the following steps: 1) uniformly mixing a permanent electret, a reversible electret, a magnetic and piezoelectric material, a dispersing agent, an antioxidant, a conductive polymer/graphene compound and polypropylene resin through a mixer, performing melt blending extrusion through a double-screw extruder, and granulating to obtain an electret master batch, wherein the process temperature is 160-240 ℃; 2) mixing the obtained electret mother particles with polypropylene, spraying out by melt-blowing equipment, and arranging a magnetic field between a spinning nozzle and a receiving device, wherein the magnetic field intensity is 0.5-5 Tesla. Adding magnetic and piezoelectric materials in the melt-blown fiber, applying a magnetic field in the process of spinning to cooling to ensure that the magnetic materials are directionally arranged, and cooling to ensure that the magnetic materials are directionally arranged, so that all the materials with piezoelectric properties have the same oriented piezoelectric effect. Therefore, the electret can be charged in the breathing process, and the service life of the mask is prolonged.

Description

Self-charging self-cleaning melt-blown non-woven fabric and mask

Technical Field

The invention relates to a self-charging self-cleaning melt-blown non-woven fabric and a mask.

Background

The meltblown used with the KN95 standard mask captures particles primarily by the dual action of mechanical barrier and electrostatic adsorption. The mechanical barrier effect is closely related to the structure and properties of the material; when the melt-blown fabric is charged by corona and then has voltage of hundreds to thousands of volts, fibers are diffused into net-shaped holes due to the repulsion action of static electricity, and the size among the fibers is far larger than that of dust, so that an open structure is formed.

When dust passes through the melt-blown filter material, electrostatic interaction can not only effectively attract charged dust particles, but also capture polarized neutral particles with electrostatic induction effect. The higher the electrostatic potential of the material, the higher the charge density of the material, the more point charges, and the stronger the electrostatic action. The corona discharge can greatly improve the filtering performance of the polypropylene melt-blown fabric. The addition of tourmaline particles can effectively improve the electret benefit, increase the filtration efficiency, reduce the filtration resistance, increase the surface charge density of the fiber and enhance the charge storage capacity of the fiber web.

However, the conventional melt-blown nonwoven fabric is deteriorated in filtration efficiency due to electrostatic attenuation when left for a long period of time, and is deteriorated in filtration efficiency and increased in resistance due to adsorption of dust particles during long-term wearing.

Disclosure of Invention

In order to overcome the defects, the invention discloses a mask containing a self-cleaning self-charging filtering melt-blown material, which has the characteristics of lasting high filtering efficiency and low resistance.

In order to achieve the purpose, the self-charging self-cleaning melt-blown non-woven fabric comprises permanent electrets and piezoelectric materials in melt-blown fibers.

Further, the processing method of the melt-blown non-woven fabric comprises the following steps:

1) uniformly mixing 1-10 parts of permanent electret, 1-10 parts of reversible electret, 1-10 parts of material with both magnetism and piezoelectricity, 0.5-5 parts of dispersing agent, 0.1-1 part of antioxidant, 0.5-5 parts of conductive polymer/graphene compound and 50-100 parts of polypropylene resin through a mixer, carrying out melt blending extrusion through a double-screw extruder, and granulating to obtain electret master batches, wherein the process temperature is 160-240 ℃;

2) mixing the obtained 1-20 parts of electret master batch with 80-100 parts of polypropylene, spraying out by a melt-blowing device, and arranging a magnetic field between a spinning nozzle and a receiving device, wherein the magnetic field intensity is 0.5-5 Tesla.

Further, the permanent electret is nano tourmaline powder, nano titanium dioxide and/or nano silicon dioxide.

Further, the reversible electret is nano-silver polyvinyl alcohol composite powder;

the preparation process comprises the following steps: dissolving polyvinyl alcohol in hot water, cooling, adding silver nitrate and Tween 80 surfactant, and adding NaBH₄Reducing agent, dispersing in polyvinyl alcohol water solution, and spray drying to obtain nanometer silver-polyvinyl alcohol composite powder.

Further, the material with both magnetic and piezoelectric properties is VS₂And/or VSe₂。

In order to achieve the purpose, the mask at least comprises one layer of the self-charging self-cleaning melt-blown non-woven fabric.

Further, the mask comprises an inner layer, a middle layer and an outer layer, wherein the inner layer is provided with a heat-conducting mesh fiber layer; the outer layer is provided with a heat dissipation mesh fiber layer, and the heat conduction mesh fiber layer of the inner layer is connected with the heat dissipation mesh fiber layer of the outer layer through heat conduction structures at two ends; the middle layer is the self-charging self-cleaning melt-blown non-woven fabric.

Further, the heat-conducting mesh layer comprises: a plurality of heat-conducting long fibers are arranged in parallel along the length direction at intervals, and a plurality of heat-conducting short fibers are laid on the plurality of heat-conducting long fibers; one end or two ends of the long fiber are provided with heat conducting sheets.

Furthermore, the diameter of the heat-conducting long fibers is more than twice of that of the heat-conducting short fibers.

Further, the inner layer is formed by reinforcing three layers of fiber nets through a hot air process, wherein,

upper layer fiber web: and respectively weighing the ES short fibers and the heat-conducting short fibers by adopting a cotton feeding weighing machine, carding and lapping by using a carding machine to form a fiber net, intermittently lapping the fiber net, and reducing lapping density at a position containing weft in the middle layer so as to expose part of the weft. The proportion of the ES short fibers and the heat-conducting short fibers is 70: 30-50: 50. square gram weight: 10-30g/m 2.

Lower layer fiber web: respectively weighing ES short fibers and heat-conducting short fibers by adopting a cotton feeding weighing machine, carding by a carding machine, and lapping to form a fiber web; the proportion of the ES short fibers and the heat-conducting short fibers is 90: 10-70: 30, of a nitrogen-containing gas; square gram weight: 10-30g/m 2.

Middle layer long silk screen: preparing a middle-layer heat-conducting long silk screen by adopting a weaving or tatting process; wherein, the warp is arranged at intervals along the length direction, and the weft is arranged discontinuously according to the preset length to form the long silk screen.

The invention adds magnetic and piezoelectric materials in melt-blown fiber, applies magnetic field to make the magnetic materials directionally arranged in the process of spinning to cooling, and makes the magnetic materials directionally arranged after cooling, therefore, all the materials with piezoelectric properties have piezoelectric effect with the same orientation. Therefore, when air is sucked, the piezoelectric material generates charges, charges the reversible charging electret master batch, and further improves the filtering efficiency under the synergistic action of the reversible charging electret master batch and the permanent electret. During expiration, piezoelectric material produces opposite charge, does not charge and discharge permanent electret master batch, nevertheless discharges reversible charging electret master batch, and melt-blown non-woven fabrics electric quantity reduces, reduces the electrostatic adsorption effect of dust and melt-blown non-woven fabrics, and the dust leaves melt-blown non-woven fabrics under the effect of expiratory pressure, reaches self-cleaning effect, can continuously keep high filtration efficiency and low resistance.

Drawings

Fig. 1 is a schematic structural diagram of a heat-conducting mesh fiber layer/a heat-dissipating mesh fiber layer according to the present invention.

Fig. 2 is a schematic structural view of a facing layer with a thermally conductive mesh layer.

Fig. 3 is a schematic structural diagram of a bottom layer with a heat-dissipating web fiber layer.

Fig. 4 is a schematic view of a heat conducting structure.

Detailed Description

The self-charging self-cleaning melt-blown non-woven fabric comprises permanent electrets and piezoelectric materials in melt-blown fibers. The processing method of the melt-blown non-woven fabric comprises the following steps:

2) mixing the obtained 1-20 parts of electret master batch with 80-100 parts of polypropylene, spraying out by a melt-blowing device, and arranging a magnetic field between a spinning nozzle and a receiving device, wherein the magnetic field intensity is 0.5-5 Tesla. In the process of spinning and cooling, a magnetic field is applied to align the magnetic materials, and the magnetic materials are aligned after cooling, so that all the materials with piezoelectric properties have the same oriented piezoelectric effect.

Among the above-mentioned materials,

1) permanent electrets:

materials: nano tourmaline powder, nano titanium dioxide and nano silicon dioxide.

The function is as follows: when the air is sucked, the piezoelectric material generates charges to charge the permanent electret master batch, so that the filtering efficiency is improved. During subsequent use, even without inhalation and/or exhalation, high filtration efficiency can be achieved by the electrostatic action of the permanent electret masterbatch due to the low air flow.

2) Reversible electrets:

materials: the nano silver and polyvinyl alcohol composite powder has the advantages that the nano silver has the effect of enhancing static electricity, and meanwhile, the nano silver has the antibacterial effect. Wherein the reversible electret is polyvinyl alcohol.

The preparation process comprises the following steps: dissolving polyvinyl alcohol in hot water, cooling, adding silver nitrate and Tween 80 surfactant, and adding NaBH₄Reducing agent, nano-silver polyvinyl alcohol composite powder is prepared by preparing nano-silver polyvinyl alcohol, dispersing the nano-silver polyvinyl alcohol into polyvinyl alcohol aqueous solution and performing spray drying

The function is as follows: when the air suction is carried out, the piezoelectric material generates charges, charges the reversible charging electret master batch, and further can improve the filtering efficiency under the synergistic action of the reversible charging electret master batch and the permanent electret. During expiration, piezoelectric material produces opposite charge, does not charge and discharge permanent electret master batch, nevertheless discharges reversible charging electret master batch, and melt-blown non-woven fabrics electric quantity reduces, reduces the electrostatic adsorption effect of dust and melt-blown non-woven fabrics, and the dust leaves melt-blown non-woven fabrics under the effect of expiratory pressure, reaches self-cleaning effect, can continuously keep high filtration efficiency and low resistance.

3) Dispersing agent: 691 modified synthetic polyester wax, paraffin, isotridecanol phosphate.

4) Antioxidant: antioxidant 1010 and antioxidant 168

5) The conductive polymer (polythiophene, polypyrrole and polyaniline)/graphene compound enhances the coupling effect of the piezoelectric material and the electret, and improves the charge-discharge efficiency

6) Materials with both magnetic and piezoelectric properties, e.g. VS₂、VSe₂And the like.

Examples

1) 2.5 parts of nano tourmaline powder, 2.5 parts of nano titanium dioxide, 5 parts of nano silver polyvinyl alcohol composite powder and 5 parts of VS ₂1 part 691 of modified synthetic polyester wax, 1.5 parts of paraffin, 0.5 part of antioxidant, 2.5 parts of conductive polymer/graphene compound and 70 parts of polypropylene resin are uniformly mixed by a mixer, and are subjected to melt blending extrusion and granulation by a double-screw extruder to obtain electret master batches, wherein the process temperature is 160-240 ℃;

2) mixing the prepared 10 parts of electret master batch with 80 parts of polypropylene, spraying out by a melt-blowing device, and arranging a magnetic field between a spinning nozzle and a receiving device, wherein the magnetic field intensity is 2 Tesla.

Comparative example: adopting permanent electret, and preparing the melt-blown non-woven fabric through on-line corona electret treatment.

According to the particle filtration efficiency test of YY 0469-2011 medical surgical mask, the pressure difference under the test area of 100cm2 is directly read from the instrument, the loading amount of sodium chloride aerosol is 5mg in each test, one test cycle comprises one mask front test and one mask back test, and the weight increment of the test mask after each cycle

Self-charging self-cleaning mask can reduce the dust loading capacity of the mask in the using process, so that the filtering efficiency of the mask is not obviously reduced, and the resistance is not obviously increased. In the aging process, the problem of electrostatic attenuation can not exist due to the adoption of self-charging to realize electrostatic adsorption, so that the performance after aging can not be obviously reduced.

As a further improvement, the mask comprises an inner layer, a middle layer and an outer layer, wherein the inner layer is provided with a heat-conducting mesh fiber layer; the outer layer is provided with a heat dissipation mesh fiber layer, and the heat conduction mesh fiber layer of the inner layer is connected with the heat dissipation mesh fiber layer of the outer layer through heat conduction structures at two ends; the middle layer is the self-charging self-cleaning melt-blown non-woven fabric.

Therefore, the heat in the mask can be conducted to the heat dissipation mesh fiber layer arranged on the outer layer through the heat conduction structure by utilizing the heat conduction mesh fiber layer arranged on the inner layer, so that the heat is dissipated through the heat dissipation mesh fiber layer, and the stuffiness in the use process can be effectively prevented.

The invention will be further described with reference to the accompanying drawings.

As shown in fig. 1, the heat conductive mesh layer of the present invention includes: a plurality of heat-conducting long fibers 1 are arranged in parallel along the length direction at intervals, and a plurality of heat-conducting short fibers 2 are laid on the plurality of heat-conducting long fibers; one or both ends of the long fibers are provided with heat conductive fins 3. Wherein, the heat-conducting long fiber 1 can be made of heat-conducting fiber (such as high heat-conducting carbon fiber, graphene fiber and the like) with higher heat-conducting coefficient or metal filament (such as silver wire) and the like; the heat-conducting long fibers with high heat conductivity coefficient can be selected with lower denier, and conversely, the heat-conducting long fibers with low heat conductivity coefficient can be selected with higher denier; considering that the heat-conducting long fiber is arranged on the inner layer, the thicker the diameter of the heat-conducting long fiber with high denier is, the more the part contacting with the skin can increase the feeling of contacting with foreign matters; it is therefore conceivable to use flat, thermally conductive filaments.

The purpose of the heat-conducting short fibers 2 is to conduct heat to which they are in contactA heat conductive long fiber 1 for conducting outside through both ends of the heat conductive long fiber 1; therefore, the heat conducting short fibers 2 are preferably made of heat conducting fibers with high heat conductivity coefficient, and are laid on the heat conducting long fibers and fixed on the long fibers by hot air or other methods. The square gram weight thereof: 10-30g/m²。

The heat conducting fin 3 is used for conducting heat of the heat conducting long fibers 1 out, and is positioned at two ends, so that the heat conducting fin is mainly convenient to connect, produce and process; it may be a sheet-like heat-conducting structure woven from heat-conducting fibers or metal filaments (such as silver wires) with high metal heat conductivity coefficient, or a heat-conducting structure prepared by spraying, adhering, and depositing.

The heat-conducting mesh fiber layer can be manufactured independently or integrally with the inner layer (outer layer); the invention is further illustrated by the method of processing the inner layer:

the inner layer is formed by reinforcing three layers of fiber nets through a hot air process, wherein,

middle layer long silk screen: preparing a middle-layer heat-conducting long silk screen by adopting a weaving or tatting process; as shown in fig. 1, the warp is a heat-conducting long fiber 1, and is arranged at intervals along the length direction, the weft is arranged at the position close to the two ends of the warp, and the weft is densely woven at the two ends of the warp to form two heat-conducting sheets 3 in the length direction.

Upper layer fiber web: and respectively weighing the ES short fibers and the heat-conducting short fibers by adopting a cotton feeding weighing machine, carding and lapping by a carding machine to form a fiber net, intermittently lapping the fiber net, and reducing lapping density at the position of the middle layer corresponding to the weft so that most parts of the heat-conducting fins 3 are exposed. The proportion of the ES short fibers and the heat-conducting short fibers is 70: 30-50: 50. square gram weight: 10-30g/m²。

Lower layer fiber web: respectively weighing ES short fibers and heat-conducting short fibers by adopting a cotton feeding weighing machine, carding by a carding machine, and lapping to form a fiber web; the proportion of the ES short fibers and the heat-conducting short fibers is 90: 10-70: 30, of a nitrogen-containing gas; square gram weight: 10-30g/m²。

After the upper layer and the lower layer are aligned, the inner layer is placed in a hot air box for hot air fixation, fig. 2 is a schematic structural diagram of the manufactured inner layer, and as can be seen from the diagram, windows (notches) are formed at two ends of the inner layer, and the heat conducting fins 3 are exposed at the windows so as to be connected with the heat conducting structure conveniently.

The heat dissipation net fiber layer related to the invention is arranged on the outer layer of the mask, the heat dissipation net fiber layer is used for better heat dissipation, the structure can adopt the same structure and process as the heat conduction net fiber layer, and the heat dissipation net fiber layer is arranged on the outer layer of the mask and is not in contact with the skin, so that the limitation of the use environment is small, the number and the denier of the heat conduction long fibers 1 can be increased, the number and the density of the heat conduction short fibers 2 can be increased, and the like. As shown in fig. 3.

Since there are several intermediate layers between the inner and outer layers, the heat conducting sheet portions of the inner and outer layers cannot be directly connected, and therefore, a heat conducting material is required to be thermally connected in a suitable manner. For example, the upper and lower heat conductive sheets may be closely sewn together by the heat conductive fibers.

Fig. 4 shows a heat-conducting connecting structure corresponding to the upper and lower heat-conducting fin structures, which may be made of fabric made of heat-conducting fibers or metal sheets. When the heat conduction structure is used, the exposed part of the heat conduction fin of the inner heat conduction net fiber layer faces outwards, the exposed part of the heat conduction fin of the outer heat dissipation net fiber layer faces inwards, and then the two heat conduction fins are connected through the heat conduction structure, so that heat conduction can be realized.

Example 2

The embodiment is obtained by adding an inner layer and an outer layer on the basis of embodiment 1:

the inner layer of the mask is formed by reinforcing three layers of fiber nets through a hot air process, wherein,

middle layer long silk screen: preparing a middle-layer heat-conducting long silk screen by adopting a weaving or tatting process; wherein, warp is Qingdao day silver textile technology ltd 70D 100% pure silver conductive fiber 1, along length direction interval arrangement, is provided with the material weft in the position of warp near both ends, and the weft is woven at warp both ends department closely and is formed two long direction's conducting strip. The pure silver fiber is adopted, and the antibacterial and deodorizing double-effect functions can be added.

Upper layer fiber web: respectively weighing ES short fibers and heat-conducting short fibers (such as high-heat-conducting carbon fibers, graphene fibers and the like) by adopting a cotton feeding weighing machine, carding and lapping by a carding machine to form a fiber net, intermittently lapping the fiber net, correspondingly arranging wefts in the middle layer,the mesh density is reduced so that the heat conductive sheet 3 is mostly exposed. The proportion of the ES short fibers and the heat-conducting short fibers is 70: 30, of a nitrogen-containing gas; square gram weight: 15g/m². Lower layer fiber web: respectively weighing ES short fibers and heat-conducting short fibers by adopting a cotton feeding weighing machine, carding by a carding machine, and lapping to form a fiber web; the proportion of the ES short fibers and the heat-conducting short fibers is 70: 30, of a nitrogen-containing gas; square gram weight: 15g/m²。

The heat-conducting short fibers are formed by adding 1% by weight of graphene to the skin layers of the ES short fibers (the addition amount of the graphene in actual production can be 0.5-5%).

After the upper layer and the lower layer are aligned, the upper layer and the lower layer are placed in a hot air box for hot air fixation, fig. 2 is a schematic structural diagram of a manufactured surface layer, and as can be seen from the diagram, windows (notches) are formed at two ends of the surface layer, and the heat conducting fins 3 are exposed at the windows so as to be connected with the heat conducting structure conveniently.

The bottom layer (outer layer) of the mask is made of the same material as the surface layer.

Two windows with exposed heat conducting fins are arranged at the left end and the right end of the mask; the inner layer and the outer layer are connected by a metal sheet.

The following table shows the results of the instantaneous cool feeling measurement performed on the above mask sample using a contact cool and warm feeling tester (KES-F7THERMO LABO ii):

as can be seen from the table above, the structure of the invention has better cool effect, and the cool effect is obviously improved along with the increase of the weight of the long fibers.

Claims

1. The self-charging self-cleaning melt-blown non-woven fabric is characterized in that melt-blown fibers of the melt-blown non-woven fabric contain permanent electrets and piezoelectric materials.

2. The self-charging self-cleaning melt-blown nonwoven fabric of claim 1, wherein the melt-blown nonwoven fabric is processed by the following method:

3. Self-charging self-cleaning melt-blown nonwoven fabric according to claim 2, wherein the permanent electrets are nano tourmaline powder, nano titanium dioxide and/or nano silicon dioxide.

4. The self-charging self-cleaning melt-blown nonwoven fabric of claim 2, wherein the reversible electret is nano-silver polyvinyl alcohol composite powder;

5. The self-charging self-cleaning melt-blown nonwoven fabric of claim 2, wherein the material having both magnetic and piezoelectric properties is VS₂And/or VSe₂。

6. A mask characterized by comprising at least one layer of the self-charging self-cleaning melt-blown nonwoven fabric according to claim 1.

7. The mask of claim 6 wherein said mask is comprised of an inner layer, an intermediate layer and an outer layer, wherein said inner layer is provided with a layer of thermally conductive mesh fibers; the outer layer is provided with a heat dissipation mesh fiber layer, and the heat conduction mesh fiber layer of the inner layer is connected with the heat dissipation mesh fiber layer of the outer layer through heat conduction structures at two ends; the middle layer is the self-charging self-cleaning melt-blown non-woven fabric.

8. The mask of claim 7 wherein said layer of thermally conductive mesh comprises: a plurality of heat-conducting long fibers are arranged in parallel along the length direction at intervals, and a plurality of heat-conducting short fibers are laid on the plurality of heat-conducting long fibers; one end or two ends of the long fiber are provided with heat conducting sheets.

9. The mask of claim 7 wherein said thermally conductive filaments have a diameter more than twice the diameter of said thermally conductive filaments.

10. The mask of claim 7 wherein said inner layer is formed by three layers of fibrous webs reinforced by a hot air process, wherein,

upper layer fiber web: and respectively weighing the ES short fibers and the heat-conducting short fibers by adopting a cotton feeding weighing machine, carding and lapping by using a carding machine to form a fiber net, intermittently lapping the fiber net, and reducing lapping density at a position containing weft in the middle layer so as to expose part of the weft. The proportion of the ES short fibers and the heat-conducting short fibers is 70: 30-50: 50; square gram weight: 10-30g/m²。