CN113261724A - Mask body, preparation method thereof and washable mask - Google Patents
Mask body, preparation method thereof and washable mask Download PDFInfo
- Publication number
- CN113261724A CN113261724A CN202110632265.3A CN202110632265A CN113261724A CN 113261724 A CN113261724 A CN 113261724A CN 202110632265 A CN202110632265 A CN 202110632265A CN 113261724 A CN113261724 A CN 113261724A
- Authority
- CN
- China
- Prior art keywords
- screen layer
- filter screen
- mask
- mask body
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- A—HUMAN NECESSITIES
- A41—WEARING APPAREL
- A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
- A41D13/00—Professional, industrial or sporting protective garments, e.g. surgeons' gowns or garments protecting against blows or punches
- A41D13/05—Professional, industrial or sporting protective garments, e.g. surgeons' gowns or garments protecting against blows or punches protecting only a particular body part
- A41D13/11—Protective face masks, e.g. for surgical use, or for use in foul atmospheres
- A41D13/1192—Protective face masks, e.g. for surgical use, or for use in foul atmospheres with antimicrobial agent
-
- A—HUMAN NECESSITIES
- A41—WEARING APPAREL
- A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
- A41D31/00—Materials specially adapted for outerwear
- A41D31/02—Layered materials
-
- A—HUMAN NECESSITIES
- A41—WEARING APPAREL
- A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
- A41D31/00—Materials specially adapted for outerwear
- A41D31/04—Materials specially adapted for outerwear characterised by special function or use
-
- A—HUMAN NECESSITIES
- A41—WEARING APPAREL
- A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
- A41D31/00—Materials specially adapted for outerwear
- A41D31/04—Materials specially adapted for outerwear characterised by special function or use
- A41D31/30—Antimicrobial, e.g. antibacterial
- A41D31/305—Antimicrobial, e.g. antibacterial using layered materials
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F1/00—General methods for the manufacture of artificial filaments or the like
- D01F1/02—Addition of substances to the spinning solution or to the melt
- D01F1/10—Other agents for modifying properties
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F1/00—General methods for the manufacture of artificial filaments or the like
- D01F1/02—Addition of substances to the spinning solution or to the melt
- D01F1/10—Other agents for modifying properties
- D01F1/103—Agents inhibiting growth of microorganisms
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
- D01F6/88—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polycondensation products as major constituent with other polymers or low-molecular-weight compounds
- D01F6/92—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polycondensation products as major constituent with other polymers or low-molecular-weight compounds of polyesters
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M10/00—Physical treatment of fibres, threads, yarns, fabrics, or fibrous goods made from such materials, e.g. ultrasonic, corona discharge, irradiation, electric currents, or magnetic fields; Physical treatment combined with treatment with chemical compounds or elements
- D06M10/02—Physical treatment of fibres, threads, yarns, fabrics, or fibrous goods made from such materials, e.g. ultrasonic, corona discharge, irradiation, electric currents, or magnetic fields; Physical treatment combined with treatment with chemical compounds or elements ultrasonic or sonic; Corona discharge
- D06M10/025—Corona discharge or low temperature plasma
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M2101/00—Chemical constitution of the fibres, threads, yarns, fabrics or fibrous goods made from such materials, to be treated
- D06M2101/16—Synthetic fibres, other than mineral fibres
- D06M2101/30—Synthetic polymers consisting of macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D06M2101/32—Polyesters
Abstract
A mask body, a preparation method thereof and a water-washable mask, wherein the mask body comprises an inner filter screen layer and an outer filter screen layer, and the inner filter screen layer and the outer filter screen layer are woven into a net by adopting a high molecular polymer containing a body charge reinforcing material and a bacteriostatic agent. This can wash gauze mask possesses lower resistance of ventilating under the equal filtration efficiency condition, wears more comfortable gauze mask.
Description
Technical Field
The invention relates to the technical field of masks, in particular to a washable mask, a mask body and a preparation method of the washable mask.
Background
With the promotion of protection consciousness of consumers and the industrial development brought by the great increase of the market of the Chinese manufacturing industry, the wearing demand of the civil mask and the industrial mask is remarkably increased, and the usage of the traditional disposable non-woven fabric mask is increased rapidly and simultaneously brings great plastic pollution harm.
The gauze mask that circulates on the existing market, the filter media mainly adopt the polypropylene non-woven fabrics to make outer layer material, the polypropylene melts the melt-blown non-woven fabrics and makes filter material, because of melting the filter efficiency of filter media and showing to be influenced by water, and the non-woven fabrics washing easily leads to the cloth to loosen, the cloth fibre is fluffy or the burr, therefore conventional gauze mask including KN95, medical gauze mask is disposable, can't wash, use the environment after the abandonment to be difficult to degrade, cause environmental pollution, retrieve again often to have inconveniently. Even if there is also repeatedly usable's gauze mask, along with its increase in service time, often have again breathe that resistance is high, the product is complicated, weight is big, wear experience scheduling problem extremely poor.
Therefore, in view of the above drawbacks, it is desirable to design a mask that is washable and still maintains sufficient filtration efficiency.
Disclosure of Invention
The invention aims to provide a mask body and a water-washable mask with the same, so that the mask has lower ventilation resistance and is more comfortable to wear under the condition of the same filtering efficiency.
In order to achieve the purpose, the invention adopts the following technical scheme:
a mask body comprises an inner layer filter screen layer and an outer layer filter screen layer, wherein the inner layer filter screen layer and the outer layer filter screen layer are woven into a net by adopting a high molecular polymer containing a bulk charge reinforcing material and a bacteriostatic agent;
correspondingly, the mesh number of the inner filter screen layer is 50-300 meshes, and the mesh number of the outer filter screen layer is 100-500 meshes;
correspondingly, the high molecular polymer comprises polyester fibers;
correspondingly, the bulk charge reinforcing material comprises spherical nano zinc oxide particles, nano tourmaline powder, nano silicon dioxide particles and nano titanium dioxide particles, the inner filter screen layer and the outer filter screen layer contain at least one of the particles, and the mass content of the bulk charge reinforcing material is 0.1-1.5%;
correspondingly, the bacteriostatic agent comprises zinc oxide, and the mass content of the zinc oxide is 0.05-1%;
correspondingly, a filtering enhancement layer is arranged between the inner-layer filter screen layer and the outer-layer filter screen layer, the filtering enhancement layer is a PTFE microporous membrane or a PTFE microporous membrane composite membrane, and the PTFE microporous membrane composite membrane is a TPFE membrane taking completely biodegradable synthetic fibers as a matrix;
correspondingly, the filter enhancement layer is compounded on the inner filter screen layer through hot pressing;
correspondingly, the gram weight of the PTFE microporous membrane is 0.5-6.0 g/m2The pore size is 0.1-2.0 μm, and the porosity is 80-95%;
correspondingly, the completely biodegradable synthetic fiber comprises a PLA fiber web with the gram weight of 18-100 g/m2。
The invention also provides a preparation method of the mask body, which comprises the following steps:
s1, heating and drying the high molecular polymer slice master batch;
s2, melting, vibrating and blending the high molecular polymer, the body charge reinforcing material master batch and the bacteriostatic agent uniformly;
s3, preparing the blend into fibers through a melt spinning process and weaving the fibers into a net;
s4, corona electret treatment of the fiber web;
and S5, cutting the filter screen into an inner filter screen layer and an outer filter screen layer, and arranging a PTFE microporous membrane or a PTFE microporous membrane composite membrane between the inner filter screen layer and the outer filter screen layer.
Correspondingly, the high molecular polymer is polyester fiber, the heating and drying temperature is 100-115 ℃, and the melting and shaking blending temperature is 135-150 ℃;
correspondingly, in step S4, the corona electret process parameters are: the electret voltage is 30-50 kV, the electret distance is 2-4 cm, the electret speed is 4m/min, the electret time is 30-50S, and the electret temperature is 20-25 ℃;
correspondingly, in step S5, the PTFE microporous membrane or PTFE microporous membrane composite membrane and the inner screen layer are hot-pressed and compounded.
The invention also provides a washable mask with the mask body, which comprises a mask body, mask fixing belts and nose bridge fixing strips, wherein the mask fixing belts are arranged on two sides of the mask body, and the nose bridge fixing strips are transversely arranged on the mask body corresponding to the nose bridge of a human body.
The invention has the beneficial effects that:
1) the filter has lower ventilation resistance on the premise of the same filtering efficiency. The lowest resistance value of a plane mask in the same grade in the current market is about 25Pa, the lowest resistance value is generally 30-50 Pa, and the breathing is not smooth enough when the mask is worn, namely, the breathing resistance is strong, but the mask can break through the air permeability bottleneck of the existing mask, the breathing resistance of the mask is averagely 9Pa, so that the resistance can hardly be felt under the condition of keeping the filtering effect of BFE95 grade;
2) the protective clothing can keep better protective stability and comfort when being worn for a long time. The filtering material is not limited by the traditional electrostatic electret process, can be washed by water without influencing the filtering effect, has the quality smaller than that of a common plane mask, and is light, comfortable and non-sensible to wear;
3) the use of non-degradable non-woven fabrics such as polypropylene and the like is completely abandoned, so that the mask can be washed and repeatedly worn, and the pollution to the environment is greatly reduced.
Detailed Description
In one embodiment of the invention, the washable mask comprises a mask body, a mask fixing band and a nose bridge fixing strip, and for simplifying the description, in the embodiment, the mask fixing band is set as an ear band, the nose bridge fixing strip is set as a nose bridge strip, the ear bands are arranged on two sides of the mask body, and the nose bridge strip is transversely arranged on the mask body corresponding to the nose bridge of a human body;
the mask body comprises an inner-layer filter screen layer, an outer-layer filter screen layer and a filter enhancement layer arranged between the inner-layer filter screen layer and the outer-layer filter screen layer, and further, in order to obtain high filtering efficiency of more than 97%. In this embodiment, a mask body with enhanced filtration efficiency is taken as an example for explanation;
the mesh number of the inner filter screen layer, namely the inner skin-close layer, is 50-300 meshes, the mesh number of the outer filter screen layer, namely the outer protective layer, is 100-500 meshes, the inner filter screen layer and the outer filter screen layer are woven into a mesh by adopting high molecular polymers containing body charge reinforcing materials and bacteriostatic agents, in the embodiment, the high molecular polymers are polyester fibers, the body charge reinforcing materials are nano silicon dioxide particles, certainly, the body charge reinforcing materials can also be one or more of spherical nano zinc oxide particles, nano tourmaline powder and nano titanium dioxide particles, and the bacteriostatic agents are zinc oxide, wherein the mass content of the nano silicon dioxide particles is 0.1-1.5%, the mass content of the zinc oxide is 0.05-1%, and the rest is polyester fibers. In order to enhance the filtration efficiency in another step, the filtration enhancement layer is compounded on the inner layer filter screen layer by hot pressing, the filtration enhancement layer is a PTFE microporous membrane or a PTFE microporous membrane composite membrane, the PTFE microporous membrane composite membrane is a TPFE membrane which takes completely biodegradable synthetic fibers as a matrix, for example, a PLA fiber net as a matrix and then the TPFE membrane is coated, so that the permeation amount of air can be greatly increased on the premise of ensuring high-efficiency filtration, and the environmental pollution is avoided due to the degradability of the TPFE membrane.
To achieve the washable mask described in the above examples, it can be prepared as follows:
firstly, preparing an inner-layer filter screen layer and an outer-layer filter screen layer;
1) drying the polyester fiber chip master batch at the temperature of 100-115 ℃;
2) melting, vibrating and uniformly mixing the dried polyester fiber, the nano silicon dioxide particles and the zinc oxide at the temperature of 135-150 ℃, and ensuring that the mass content of the nano silicon dioxide particles is 0.1-1.5% and the mass content of the zinc oxide is 0.05-1%;
3) preparing, rolling and weaving into a net through a melt spinning process, and ensuring that the mesh number of an inner filter screen layer is 50-300 meshes and the mesh number of an outer filter screen layer is 100-500 meshes;
4) performing corona electret treatment on the filter screen under the conditions of electret voltage of 30-50 kV, electret distance of 2-4 cm, electret speed of 4m/min, electret time of 30-50S and electret temperature of 20-25 ℃.
Secondly, preparing a filtering enhancement layer;
selecting the gram weight of 0.5-6.0 g/m2And the PTFE microporous membrane or PTFE microporous membrane composite membrane has a pore size of 0.1-2.0 μm and a porosity of 80-95%.
Thirdly, cutting and sewing;
1) cutting the inner filter screen layer, the outer filter screen layer and the filter enhancement layer into a formed size, wherein the cutting mode can be conventional mechanical cutting or laser cutting, and the laser cutting can lock the edge to avoid the phenomenon that edge fibers fall off;
2) folding the cut inner filter screen layer, the cut outer filter screen layer and the cut filter enhancement layer into a required mask style, firstly thermally compounding the filter enhancement layer on the inner filter screen layer, and then sewing and fixing the edges of the cloth by using yarns;
3) respectively placing the nose bridge strip (such as a PE plastic strip or a beeswax plastic strip) and the head end of the ear belt into the sewing position of the cloth, and further sewing and fixing the nose bridge strip and the ear belt to obtain the finished mask.
The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.
Claims (10)
1. The utility model provides a gauze mask body which characterized in that, includes inlayer filter screen layer and outer filter screen layer, inlayer filter screen layer with outer filter screen layer all adopts the macromolecular polymer who contains body charge reinforcing material and bacteriostatic to weave into the netting.
2. The mask body according to claim 1, wherein the mesh number of the inner screen layer is 50 to 300 mesh, and the mesh number of the outer screen layer is 100 to 500 mesh.
3. The mask body of claim 1 wherein the high molecular weight polymer comprises polyester fibers.
4. The mask body according to claim 1, wherein the bulk charge enhancer comprises spherical nano zinc oxide particles, nano tourmaline powder, nano silica particles and nano titania particles, the inner filter layer and the outer filter layer contain at least one of the particles, and the mass content of the bulk charge enhancer is 0.1-1.5%.
5. The mask body according to claim 1, wherein the bacteriostatic agent comprises zinc oxide, and the mass content of the zinc oxide is 0.05-1%.
6. The mask body according to claim 1, wherein a filtration enhancement layer is further disposed between the inner screen layer and the outer screen layer, the filtration enhancement layer is a PTFE microporous membrane or a PTFE microporous membrane composite membrane, and the PTFE microporous membrane composite membrane is a TPFE membrane using fully biodegradable synthetic fibers as a matrix.
7. A method for preparing the mask body according to claims 1 to 9, comprising the following steps:
s1, heating and drying the high molecular polymer slice master batch;
s2, melting, vibrating and blending the high molecular polymer, the body charge reinforcing material master batch and the bacteriostatic agent uniformly;
s3, preparing the blend into fibers by a melt spinning process after corona electret treatment, and weaving the fibers into a net;
s4, corona electret treatment of the fiber web;
and S5, cutting the filter screen into an inner filter screen layer and an outer filter screen layer, and arranging a PTFE microporous membrane or a PTFE microporous membrane composite membrane between the inner filter screen layer and the outer filter screen layer.
8. The method for preparing a mask body according to claim 7, wherein the high molecular polymer is a polyester fiber, the heating and drying temperature is 100-115 ℃, and the melt oscillation blending temperature is 135-150 ℃.
9. The method of claim 7, wherein in step S3, the corona electret process parameters are: the electret voltage is 30-50 kV, the electret distance is 2-4 cm, the electret speed is 4m/min, the electret time is 30-50S, and the electret temperature is 20-25 ℃.
10. A washable mask with a mask body according to claims 1-6, comprising mask fixing straps, nose bridge fixing straps and said mask body, wherein said mask fixing straps are disposed on both sides of said mask body, and nose bridge fixing straps are transversely disposed on said mask body corresponding to the nose bridge of a human body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110632265.3A CN113261724A (en) | 2021-06-07 | 2021-06-07 | Mask body, preparation method thereof and washable mask |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110632265.3A CN113261724A (en) | 2021-06-07 | 2021-06-07 | Mask body, preparation method thereof and washable mask |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113261724A true CN113261724A (en) | 2021-08-17 |
Family
ID=77234450
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110632265.3A Pending CN113261724A (en) | 2021-06-07 | 2021-06-07 | Mask body, preparation method thereof and washable mask |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113261724A (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101591837A (en) * | 2009-07-08 | 2009-12-02 | 天津工业大学 | A kind of double-component melt-blown durable electret non-woven fabric and manufacture method thereof |
| CN203873053U (en) * | 2014-06-10 | 2014-10-15 | 武汉龙飞翔科技产品制造有限公司 | Mask with e-PTFE microporous membranes |
| DE202020101788U1 (en) * | 2020-04-02 | 2020-05-04 | SCi Kontor GmbH | Multi-layer mask with reversible, removable multi-layer filter for repeated use and cleaning options |
| CN111567927A (en) * | 2020-04-10 | 2020-08-25 | 北京大学深圳研究生院 | Hydrophobic sterilization mask |
| TWM603779U (en) * | 2020-08-25 | 2020-11-11 | 劉朝芳 | Improved mask |
| CN212325496U (en) * | 2020-05-12 | 2021-01-12 | 堤麦策略行销有限公司 | Gauze mask |
| CN112263030A (en) * | 2020-11-16 | 2021-01-26 | 江苏泰氟隆科技有限公司 | Planar protective mask adopting PTFE nano filter material |
| CN112773019A (en) * | 2021-01-29 | 2021-05-11 | 腾飞科技股份有限公司 | Protective mask capable of being washed repeatedly and preparation process thereof |
-
2021
- 2021-06-07 CN CN202110632265.3A patent/CN113261724A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101591837A (en) * | 2009-07-08 | 2009-12-02 | 天津工业大学 | A kind of double-component melt-blown durable electret non-woven fabric and manufacture method thereof |
| CN203873053U (en) * | 2014-06-10 | 2014-10-15 | 武汉龙飞翔科技产品制造有限公司 | Mask with e-PTFE microporous membranes |
| DE202020101788U1 (en) * | 2020-04-02 | 2020-05-04 | SCi Kontor GmbH | Multi-layer mask with reversible, removable multi-layer filter for repeated use and cleaning options |
| CN111567927A (en) * | 2020-04-10 | 2020-08-25 | 北京大学深圳研究生院 | Hydrophobic sterilization mask |
| CN212325496U (en) * | 2020-05-12 | 2021-01-12 | 堤麦策略行销有限公司 | Gauze mask |
| TWM603779U (en) * | 2020-08-25 | 2020-11-11 | 劉朝芳 | Improved mask |
| CN112263030A (en) * | 2020-11-16 | 2021-01-26 | 江苏泰氟隆科技有限公司 | Planar protective mask adopting PTFE nano filter material |
| CN112773019A (en) * | 2021-01-29 | 2021-05-11 | 腾飞科技股份有限公司 | Protective mask capable of being washed repeatedly and preparation process thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203226301U (en) | Filtering mask | |
| JPWO2018221381A1 (en) | mask | |
| CN111165956B (en) | Washable mask capable of effectively blocking viruses and bacteria and preparation method thereof | |
| CN210234280U (en) | Filtering protective fabric for mask | |
| CN111602903A (en) | Preparation process method of high-polymer-material high-filterability non-woven mask | |
| CN112078203A (en) | Mask with three layers of different-shaped structures and preparation method thereof | |
| CN110393978A (en) | A kind of antibacterial ordor removing non-woven filter material and its application | |
| CN113261724A (en) | Mask body, preparation method thereof and washable mask | |
| CN210706410U (en) | Activated carbon non-woven fabric for mask | |
| CN111616450A (en) | Non-medical nano-film filtering mask | |
| CN204763519U (en) | Can dismantle dust mask | |
| CN213247041U (en) | Cool moisture absorption quick-drying mask | |
| CN213247056U (en) | Degradable environmental protection gauze mask | |
| KR102382941B1 (en) | Filter media for air filtration and dust mask using it | |
| CN113199835A (en) | Critical low-resistance mask and production process thereof | |
| CN111513391A (en) | Protective mask and processing technology | |
| CN111631461A (en) | Antibacterial and antivirus washable multifunctional mask and preparation method thereof | |
| CN218164344U (en) | Nanoscale melt-blown fabric environment-friendly mask with low air resistance | |
| CN113308797B (en) | Melt-blown fabric, method for producing same, mask and air filter device comprising same | |
| CN106480604B (en) | A kind of mask lining cloth and its manufacturing method | |
| CN212949587U (en) | Three-layer mask with anisotropic structure | |
| CN213227839U (en) | Antibacterial breathable fabric for mask | |
| CN218999607U (en) | PVB-containing composite antibacterial nanofiber mask | |
| CN213045305U (en) | Mask with rapidly replaceable filter element | |
| CN217337509U (en) | High-efficient protection type parent's skin gauze mask |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20210817 |