Stepped filter dust mask

Abstract

Provided in the present invention is a long-lasting dust mask based on a metal fiber-based stepped filter structure for high-concentration dust working environments such as mines, metallurgy, chemical industry, construction, and ceramics. The dust mask comprises a mask body, a filter layer structure, and a filter cartridge , wherein the filter layer structure comprises a double-layer metal fiber cloth, electrostatic cotton, and a melt-blown fiber cloth, the two layers of the double-layer metal fiber cloth being arranged in close contact with each other; in order to achieve a better dust removal effect, each metal fiber bundle is composed of metal fiber filaments with a fiber diameter ranging from 8 μm to 12 μm; when dust enters the fiber bundles, tens of thousands of fiber filaments of the fiber bundles can change the flow direction of the dust, and primary interception and filtration of total dust are realized by means of physical woven channels of the metal fiber cloth; and after passing through deceleration and redirection channels formed by the metal fiber cloth, fine dust is subjected to fine filtration in the electrostatic cotton and the melt-blown fiber cloth, resulting in a better filtering effect.

Description

A step-by-step filtering dust mask TECHNICAL FIELD

[0001] The present application belongs to the technical field of dust prevention, and particularly relates to a step-by-step filtering dust mask. It is suitable for the working environment of high-concentration dust in various industries, including the dust protection of individual workers in the mining, metallurgy, chemical industry, building material, construction, and ceramic industries, and can prevent the respiratory system of dust-exposed workers from being damaged. BACKGROUND

[0002] With the continuous increase of mining mechanization level, the mining depth and mining conditions are further deteriorated, the dust exposure problem is increasingly serious, and the occupational health of mine workers is seriously affected. Preventing occupational pneumoconiosis has become an urgent and realistic demand. According to the occupational health prevention and control requirements of various countries, key enterprises involving dust such as mines, metallurgy, chemical industry, building materials, construction, and ceramics take active dust prevention measures against dust pollution, but the dust concentration in some workplaces still exceeds the standards of various countries, and wearing individual dust masks has become the last line of defense to protect the health of workers' lungs.

[0003] Currently, workers in general dust concentration workplaces generally wear self-suction KN95 dust masks for individual protection. The KN95 dust mask integrates multiple filter materials (non-woven fabric, electrostatic cotton, and melt-blown fiber) into a whole, and realizes dust interception through electrostatic adsorption of the filter material. The dust filtration efficiency is not less than 95%. In high-concentration dust environments, to further improve the protection effect, various countries have increased the protection standard grade. KN100 type dust masks with a filtration efficiency of 99.97% can effectively isolate respirable dust and have been developed and gradually applied in places with higher protection requirements and have entered the standard system of various countries.

[0004] For KN100 dust masks, the world has adopted increasing the thickness of filter material to improve the filter layer to achieve high-efficiency filtration. However, with the thickening of the filter layer, the respiratory resistance also increases. Therefore, the current protective mask reduces the filtration resistance by increasing the filter area of the filter box or using a double breathing valve, which significantly increases the size and use cost of the mask. TECHNICAL PROBLEM

[0005] However, in high-concentration dust environments such as mines, due to the high concentration and dispersion of dust, for example, more than 70% of the dust particles in respirable dust are larger than 2um, the respiratory resistance of workers wearing KN100 dust masks can still meet the respiratory requirements for a short time, but if they wear it for more than 4 hours, a large amount of dust will be adsorbed on the filter material, increasing the respiratory resistance. Due to the electrostatic adsorption effect of the filter material, the dust cannot fall off, and in the later stage of an 8-hour work period, the respiratory resistance is high, and the wearing effect is not good. Currently, mine workers in high-concentration environments change the filter cotton once a day or 2-4 times a day. Low-resistance long-term operation is a bottleneck that existing KN100 dust masks cannot break through.

[0006] From the existing dust mask technology, the filter assembly is generally composed of non-woven fabric, electrostatic cotton, melt-blown fiber cloth and other materials. The non-woven fabric and electrostatic cotton are used to physically intercept and filter dust, and the melt-blown fiber is used to filter fine dust by electrostatic adsorption. When the dust-containing airflow is inhaled into the filter box, the large particles of dust are first intercepted by the non-woven fabric, and then the small particles and fine particles of dust enter the electrostatic cotton. The electrostatic cotton uses the feature of large thickness to deposit dust and increase the dust capacity. The part of fine dust that escapes is finally electrostatically adsorbed by the melt-blown fiber cloth, and finally a good filtering performance is achieved. In addition, some technologies increase the filtering area by using a filter material with a pleated structure, and integrate a single replaceable filter box to achieve large-area filtering and overall replacement. However, this also makes the production process of the filter assembly more complex and the replacement cost increases significantly.

[0007] The present innovative technology proposes a long-acting low-resistance dust mask with a gradient structure of metal fiber cloth and melt-blown fiber cloth. The first-stage metal fiber cloth realizes primary interception and filtration of all dust through physical weaving channels. The fine dust that escapes from the first stage is filtered by electrostatic adsorption in the second-stage electrostatic cotton and melt-blown fiber cloth. The first-stage metal fiber cloth can filter about 90% of all dust, and the second stage completes the filtration of the remaining dust, with a comprehensive filtration efficiency of 99.98%. The present innovative technology also utilizes the anti-static property of the metal fiber cloth. After the metal fiber cloth accumulates a certain amount of dust, the metal fiber cloth can be cleaned by shaking or patting the mask. After cleaning, the metal fiber cloth returns to its initial state, and the resistance is reduced to near the initial state, achieving the purpose of reducing respiratory resistance without replacing the filter material. This innovative technology enables the metal filter layer to be reused, greatly reducing the dust accumulation rate of the second-stage filter layer and significantly extending the service life of the second-stage filter layer. Field applications show that the use of metal fiber cloth can extend the service life of the second-stage filter layer by more than 3 times compared to traditional dust masks. In mining sites, the filter replacement time can be extended to 3-5 days per piece, significantly reducing the frequency of filter replacement and the overall use cost. Technical solutions

[0008] The present application is aimed at the high-concentration dust working environment of mines, metallurgy, chemical industry, building materials, construction, ceramics, etc. A long-acting low-resistance dust mask with a step structure of metal fiber cloth and melt-blown fiber cloth, a step filtration dust mask includes a mask body, a filter layer structure, and a filter box. The filter layer structure includes double-layer metal fiber cloth, electrostatic cotton, and melt-blown fiber. The two layers of double-layer metal fiber cloth are arranged closely, and the textures of the two layers are arranged in a staggered manner, forming deflection and backflow of the airflow flow path. Dust-containing airflow realizes collision, deceleration, and turning of dust and fibers during the flow process, thereby achieving primary interception of large-particle dust. The electrostatic adsorption effect of electrostatic cotton and melt-blown fiber on fine particles is used to realize efficient capture of fine dust, solving the problem that the service life of the filter cotton layer is reduced due to the accumulation of a large amount of dust on the filter cotton layer and the increase of filtration resistance in the traditional dust mask using only the filter cotton layer.

[0009] Further, the metal fiber cloth is woven from metal fiber bundles, and the metal fiber bundle is composed of a plurality of metal fiber filaments. The weaving method is that the warp metal fiber bundle and the weft metal fiber bundle are interwoven in a non-vertical manner.

[0010] Further, the metal fiber bundle is composed of a plurality of metal fiber filaments with a fiber diameter of 8 μm ≤ fiber diameter ≤ 12 μm. When dust enters the fiber bundle, the number of fiber filaments in the fiber bundle reaches tens of thousands, which can change the flow direction of captured dust, so that the dust continuously turns between the fiber filaments, thereby reducing the dust movement speed and finally settling.

[0011] Further, the metal fiber cloth is woven by using twill weaving or satin weaving method. Common weaving methods for woven filter cloth include plain weave, twill weave, and satin weave. In twill weaving or satin weaving, the interlacing points of warp yarns and weft yarns present a certain diagonal pattern every two or more yarns are interwoven. Although the interlacing points of twill fabric or satin fabric are less than those of plain fabric, the floating lines between warp yarns and weft yarns are relatively long, which makes the fabric have a certain elasticity and softness in structure. At the same time, due to the reduction of interlacing points, the pore size is relatively large and unevenly distributed. This structure is beneficial to the passage of gas, reduces resistance, and improves filtration efficiency. During the filtration process, the larger pore size can allow more gas to pass through while retaining larger dust particles.

[0012] The double-layer metal fiber cloth is adopted in the application to realize interception of large-particle dust in the whole dust, and the two layers of fiber cloth are arranged in a staggered manner, the first layer of fiber weaving aperture is corresponding to the second layer of fiber weaving dense place. When the dust-containing airflow passes through, the dust can pass through the metal fiber cloth smoothly, and the dust is intercepted after being slowed down by the impingement on the metal fiber under the flow around the metal fiber, and loses the kinetic energy for advancing. Part of the dust that is not intercepted enters the next layer of metal fiber along with the airflow, and at this time, due to the dense arrangement between the fibers, the dust continuously collides with the fibers when passing through the fibers, and is further intercepted and deposited in the airflow dead zone formed between the fibers, and is not further sucked into the next layer. A small part of the dust with a smaller particle size (about 0~2.5μm) can also be intercepted by the rear filter cotton layer.

[0013] The metal fiber cloth used in the application has the excellent properties of metal, so that it has good self-cleaning function. The metal surface has high surface tension, which reduces the adhesion between the dust particles and the metal surface; the metal surface is smooth, which reduces the contact points between the dust and the metal surface, and reduces the opportunity for continuous adhesion of the dust; the metal has good electrical conductivity, which can effectively dissipate static electricity and avoid the accumulation of static electricity to avoid the dust adhering to the surface of the metal fiber by the electrostatic adsorption effect. Based on these characteristics, the metal fiber cloth has good self-cleaning function, and the dust deposited in the gap between the metal fibers can be simply cleaned off by patting, so that the metal fiber cloth can be reused, and the metal fiber cloth and the filter cotton layer are tightly placed in the filter box.

[0014] The metal fiber cloth used in the application has hydrophobicity, and after water washing and cleaning, the water remains only on the surface of the fiber and does not enter the inside of the fiber, so that the metal fiber cloth can be quickly dried after water washing and flushing. The metal material is made of metal material, which has higher strength and longer service life.

[0015] Further, the filter box comprises a front panel and a rear panel, and the front panel and the rear panel are connected by buckling, and the filter layer is sealed between the front panel and the rear panel.

[0016] Further, the filter box and the mask body are detachably connected by buckling.

[0017] Further, in order to ensure that the airflow entering the filter box during inhalation does not directly enter the filtered chamber from the four edges of the filter layer, the edges of the filter layer are sealed and connected with the four edge portions of the inner cavity of the filter box by the sealing assembly, so as to ensure that the inhalation airflow passes through the filter layer.

[0018] Further, the electrostatic cotton and the melt-blown fiber cloth are produced by using an electret, the fiber surface forms an electric potential, the fiber surface forms an electrostatic field, after the dust-containing airflow is filtered by the metal fiber, the medium and large particle dust is intercepted, the fine dust has a large specific surface area and light mass, and the fine dust is easily adsorbed by the electrostatic adsorption when passing through the fiber, so that the fine dust is efficiently filtered.

[0019] Further, the mask body is provided with a breathing valve, the inhalation valve connected with the filter box is opened during inhalation, the airflow passes through the filter box and enters the mask body, and the inhalation valve is tightly closed during exhalation, the exhalation valve is opened, and the airflow flows out from the exhalation valve without passing through the filter box. The mask body is made of liquid silicone, which can make the mask body more fit the face and meet the ergonomic principle, thereby improving the wearing comfort and ensuring the airtightness during protection. Two ear hooks are symmetrically arranged on the two sides of the mask body, which are used for fixing the wearing rope or the elastic band. The fixing of the wearing rope or the elastic band can ensure that the mask body is stably connected to the face of the wearer.

[0020] To verify the dust filtration and protection effect of the dust mask in a real scene such as a mine, two types of workers, namely, a tunneling worker and a support worker, who are exposed to high dust concentration, are selected to wear three types of test samples, namely, a single layer of metal fiber + low resistance filter cotton, double layers of metal fiber + low resistance filter cotton, and a traditional dust filter core (single filter cotton), respectively, for a field test in a high-concentration dust environment in a coal mine. The workers wear the samples for one shift (8 hours) without removing the samples in the middle.

[0021] The metal fiber layer and the filter cotton layer of the three types of dust masks are subjected to appearance analysis and dust interception analysis. The appearance analysis shows that the sample of the traditional dust filter core (single filter cotton) is filled with dust from the inside to the outside, and the sample has reached the dust capacity limit. A large amount of dust is accumulated on the surface of the sample of the single layer of metal fiber + low resistance filter cotton, while only a small amount of dust is accumulated on the surface of the filter cotton of the sample of the double layers of metal fiber + low resistance filter cotton, and most of the dust is intercepted by the double layers of metal fiber cloth.

[0022] The comparison test results of the two types of samples containing metal filter layers, namely, the single layer of metal fiber + low resistance filter cotton and the double layers of metal fiber + low resistance filter cotton, show that the dust interception ratios of the metal fiber filter layers of the tunneling worker are 63.85% and 92.75% respectively, and the dust interception ratios of the metal fiber filter layers of the support worker are 60.92% and 88.17% respectively. The sample of the double layers of metal fiber + low resistance filter cotton can achieve efficient interception of all dust, with an interception rate of 88.17% to 92.75%, which greatly reduces the amount of dust penetrating the metal fiber into the filter cotton layer, indicating that the dust mask designed in the application can achieve massive interception of all dust and fine dust filtration.

[0023] The long-acting low-resistance dust mask with a metal fiber cloth and melt-blown fiber cloth step structure is provided by the present innovative technology. The primary interception and filtration of all dust is realized through the physical weaving channel of the first metal fiber cloth. The fine dust escaping from the first stage is precisely filtered through electrostatic adsorption in the electrostatic cotton and melt-blown fiber cloth in the rear stage (second stage). The first metal fiber cloth can filter about 90% of all dust, and the rear stage completes the filtration of the remaining dust, with a comprehensive filtration efficiency of 99.98%. The present innovative technology also utilizes the anti-static property of the metal fiber cloth. After the metal fiber cloth accumulates a certain amount of dust, the metal fiber cloth can be cleaned by shaking or patting the mask. After cleaning, the metal fiber cloth returns to the initial state, and the resistance is reduced to near the initial state, achieving the purpose of reducing respiratory resistance without replacing the filter material. This innovative technology, due to the above advantages, enables the metal filter layer to be reused, greatly reducing the dust collection rate of the rear filter layer and significantly improving the service life of the rear filter layer. Field application shows that, after using the metal fiber cloth, the service life of the rear filter layer is more than 3 times longer than that of the traditional dust mask filter layer. In mining sites, the filter replacement time can be increased to 3-5 days per piece, greatly reducing the filter replacement frequency and comprehensive use cost. Advantages

[0024] Advantages of the present invention:

[0025] (1) Combining the high dust concentration and wide particle size distribution in mining, metallurgy, chemical industry, building materials, construction, ceramics and other operating sites, a new concept of dust filtration in dust masks is proposed. The first stage (front stage) uses double-layer metal fiber cloth to achieve primary filtration of all dust, with a filtration efficiency of 88.17%~92.75%. The fine dust escaping from the front stage is precisely filtered by electrostatic cotton and melt-blown fiber, with a comprehensive filtration efficiency of 99.98%.

[0026] (2) Utilizing the anti-static property of the metal fiber cloth, the metal fiber cloth can be cleaned by shaking or patting the mask after accumulating a certain amount of dust. After cleaning, the metal fiber cloth returns to the initial state, and the resistance is reduced to near the initial state, achieving the purpose of reducing respiratory resistance without replacing the filter material. In high-concentration dust environments, the long-acting low-resistance use of protective masks is realized. Actual tests show that the resistance of the metal cloth is reduced by more than 50 Pa before and after cleaning, and the respiratory resistance is significantly reduced during use.

[0027] (3) The metal fiber cloth replaces the dust holding function of the traditional mask electrostatic cotton, greatly reducing the thickness of the mask filter cotton layer, achieving a reduction in the overall initial filtration resistance, and reducing the overall initial respiratory resistance of the traditional similar filter grade mask by more than 7.8%, improving the respiratory experience of the workers wearing the mask.

[0028] (4) After using the metal fiber cloth, the service time of the filter material layer of the rear stage is more than 3 times of that of the traditional dust mask, and in the mining site, the filter material replacement time can be increased to 3-5 days / piece, which greatly reduces the filter material replacement frequency and the comprehensive use cost. BRIEF DESCRIPTION OF DRAWINGS

[0029] Fig. 1 is a disassembled view of a dust mask with a metal fiber cloth, electrostatic cotton and melt-blown fiber structure;

[0030] Fig. 2 is a filter layer structure diagram;

[0031] Fig. 3 is a whole structure diagram of a dust mask with a metal fiber cloth, electrostatic cotton and melt-blown fiber structure;

[0032] Fig. 4 is a plain weave, twill weave and satin weave structure diagram;

[0033] Fig. 5 is a reference diagram of a metal fiber bundle composed of a plurality of metal fiber filaments in use.

[0034] Reference signs:

[0035] 1, first layer of metal fiber cloth, 2, second layer of metal fiber cloth, 3, electrostatic cotton, 4, melt-blown fiber, 5, front panel, 6, rear panel, 7, mask body. Embodiment of the present application

[0036] The embodiments of the present application will be described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application. Example 1:

[0037] As shown in Figure 1, the present application provides a step-by-step filtering dust mask including a mask body 7, a filter layer structure and a filter box, the filter layer structure including double-layer metal fiber cloth, i.e. a first layer of metal fiber cloth 1 and a second layer of metal fiber cloth 2; fiber filter cloth, i.e. electrostatic cotton 3 and melt-blown fiber 4, the two layers of double-layer metal fiber cloth being arranged closely and the textures of the two layers being arranged in staggered positions, the filter box including a front panel 5 and a rear panel 6, the front panel 5 and the rear panel 6 being connected by means of buckling, and the filter layer being sealed between the front panel and the rear panel, as shown in Figure 2, the double-layer metal fiber cloth and the fiber filter cloth (electrostatic cotton 3 and melt-blown fiber 4) being separable, the fiber filter cloth (electrostatic cotton 3 and melt-blown fiber 4) being replaceable individually, and the double-layer metal fiber cloth being recyclable, as shown in Figure 3, the filter box and the mask body 7 being detachably connected by means of buckling, facilitating quick assembly and quick disengagement between the mask body 7 and the filter box, the dust-containing airflow entering the filter box through the front panel 5 of the filter box, colliding with the double-layer metal fiber cloth, and forming deflection and backflow of the airflow flow path, the dust-containing airflow achieving collision, deceleration and turning of the dust with the fibers in the flow process, thereby achieving primary interception of large-particle dust, and the fine dust further advancing to the electrostatic cotton 3 and the melt-blown fiber 4, and achieving efficient capture of the fine dust by means of electrostatic adsorption of the fine particles by the electrostatic cotton 3 and the melt-blown fiber 4, thereby solving the problem of the traditional dust mask using only the filter cotton layer to filter dust, a large amount of dust accumulating in the filter cotton layer, increasing the filtration resistance, and thereby reducing the service life of the filter cotton layer. Example 2:

[0038] The difference between Example 1 and the present application is that the metal fiber cloth is woven from metal fiber bundles and the metal fiber cloth is woven by means of twill weaving, as shown in Figure 4, in plain weaving, the warp yarn and the weft yarn are interwoven in the rule of one above one, i.e. every other yarn is interwoven, so that the interwoven points are numerous and uniformly distributed, while in twill weaving or satin weaving, the yarns are interwoven every two or more, this interweaving method makes the surface of the fabric form obvious diagonal lines, the pore size of the twill fabric or the satin fabric is relatively large and unevenly distributed, this structure is beneficial to the passage of gas, reduces resistance and improves filtration efficiency, in the filtration process, the larger pore size can allow more gas to pass through, while retaining larger dust particles, the twill fabric or the satin fabric has good elasticity and softness, which makes it better adhere to the filter surface when subjected to external force, reduces air leakage and improves filtration efficiency, as shown in Figure 5, the metal fiber bundle is composed of multiple metal fiber filaments with a fiber diameter of 8 μm ≤ fiber diameter ≤ 12 μm, when dust enters the fiber bundle, the number of fiber bundles reaches tens of thousands of fiber filaments, which can change the flow direction of the captured dust, so that the dust constantly changes direction between the fiber filaments, thereby reducing the dust movement speed and finally settling, achieving good dust removal effect.

[0039] The above merely describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements without departing from the principles of the present application, and these improvements should also be considered as the protection scope of the present application.

Claims

1. A step filter dust mask comprising a mask body, a filter layer structure, and a filter cartridge, characterized by, The filter layer structure comprises double-layer metal fiber cloth, electrostatic cotton and melt-blown fiber, the two layers of the double-layer metal fiber cloth are closely arranged, and the textures of the two layers are arranged in staggered manner, the filter layer structure is sealed in the filter box, the filter box is provided with breathing valves at front and back sides, and air exchange of the mask can be realized.

2. A step-filter dust mask according to claim 1, wherein, The metal fiber cloth is woven by metal fiber bundles, and the metal fiber bundle is composed of a plurality of metal fiber filaments.

3. The step-by-step filtering dust mask according to claim 2, wherein the metal fiber bundle is composed of a plurality of metal fiber filaments with a fiber diameter of 8-12 microns.

4. A step-filter dust mask according to claim 3, wherein, The metal fiber cloth is woven by using twill weaving or satin weaving method.

5. The step-filter dust mask according to any one of claims 1-4, wherein, The filter box comprises a front panel and a rear panel, and the front panel and the rear panel are connected by buckling, and the filter layer is sealed between the front panel and the rear panel.

6. A step-filter dust mask according to claim 5, wherein, The filter box and the mask body are detachably connected by buckling.

7. A step-filter dust mask according to claim 6, wherein, The edges of the filter layer are sealed and connected with the peripheral edge portions of the inner cavity of the filter box by the sealing assembly, so that the air flow is ensured to pass through the filter layer.

8. A step-filter dust mask according to claim 7, wherein, The electrostatic cotton and the melt-blown fiber cloth are produced by using an electret, so that an electric potential is formed on the surface of the fiber, and an electrostatic field is formed on the surface of the fiber.

9. A step-filter dust mask according to claim 8, wherein, The mask body is provided with a breathing valve, the air suction valve connected with the filter box is opened during air suction, the air flow passes through the filter box and enters the mask body, the air suction valve is tightly closed during air exhalation, the air exhalation valve is opened, the air flow flows out from the air exhalation valve without passing through the filter box.

10. A step-filter dust mask according to claim 9, wherein, The mask body is made of liquid silicone rubber, and two hanging ears are symmetrically arranged on the two sides of the mask body.

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