CN113349484A - Method for enhancing filtering effect of mask and mask prepared by method - Google Patents

Abstract

The invention relates to a method for enhancing the filtering effect of a mask and the mask prepared by the method. By utilizing the method, the charges generated by the direct-current high-voltage discharge are implanted into the mask to complete the electrostatic secondary charging of the mask, so that the electrostatic adsorption function of the mask is further enhanced or the defects of the filtering effect caused by overdue masks and unqualified melt-blown cloth are compensated, the charges are obtained again and put into emergency use again, the use requirements are met, the mask is recycled, and the waste of raw materials is avoided. Fundamentally solved the gauze mask manufacturer and can only rely on melt to spout the cloth raw and other materials product quality and guarantee the predicament of gauze mask overall quality for gauze mask manufacturer oneself can guarantee the quality of gauze mask. In addition, the mask subjected to the additional integral polarization treatment has the advantages that the electrostatic potential is increased, the carrying charge amount is increased, the area of a charge spreading area is increased, the reduction speed of the integral charge carrying amount is objectively reduced, and the mask shows better charge holding performance in storage and general operation.

Description

Method for enhancing filtering effect of mask and mask prepared by method

Technical Field

The invention relates to the technical field of protective articles, in particular to a method for enhancing the filtering effect of a mask and the mask prepared by the method.

Background

In recent years, as environmental problems have increased due to development and progress of society, consciousness of human protection has been raised by threatening the physical health of human beings, and protective articles, particularly, masks have been widely used. Most of the existing common masks are non-woven fabric masks, and have the characteristics of ventilation, no toxicity, flexibility and durability; in order to effectively obstruct the suction of dust, dust and spray, the filter layer is usually arranged in the middle of the non-woven fabric of the mask to mostly adopt melt-blown fabric, and the melt-blown fabric has an electrostatic adsorption function, so that the dust, the spray and the like outside can be adsorbed on the surface of the non-woven fabric outside to prevent the dust, the spray and the like from entering the non-woven fabric inside, and the main filtering and obstructing effects of the mask are achieved.

The application of melt-blown nonwoven fabrics in the field of filter materials has been very extensive, and various electrostatic filters having various characteristics, such as various charging techniques and charging techniques by mixing different fibers, have been developed and utilized since the 70's 20 th century. The direct result is that an electrostatic electret method (process) is present. The filtration performance of the melt-blown nonwoven fabric is not so strong as to exceed 70%, and basically utilizes the mechanical barrier effect of the three-dimensional fiber assembly with fine fibers, small gaps and high porosity of the melt-blown superfine fibers. To improve the filtration effect, the thickness of the melt-blown fabric can only be increased, but the filtration resistance is inevitably greatly increased by increasing the gram weight and the thickness of the material. Therefore, the melt-blown filter material generally adds electrostatic charge effect to the melt-blown fabric through an electrostatic electret process, and the filtration efficiency is improved by using an electrostatic method and can reach more than 99 percent, namely the KN95 standard.

Melt-blown electret filter materials capture particles primarily through the dual action of mechanical barrier and electrostatic adsorption. The mechanical blocking effect is closely related to the structure and the property of the material, when the melt-blown cloth is charged by corona and then has a voltage of hundreds to thousands of volts, the fibers are diffused into net-shaped holes due to the repulsion effect 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 the charged charge, and the stronger the electrostatic interaction.

The existing electret methods mainly comprise an electrostatic spinning method, a corona charging method, a friction electrification method, a thermal polarization method, a low-energy electron beam bombardment method and the like. Because the electrostatic electret methods (processes) of materials are different, the properties of the formed electret are also different, and the former two methods are mainstream in the field of sanitary protection at present. However, in view of the complexity of the process and the production cost, the corona charging method is a technique which is usually adopted by mask enterprises in China.

The conventional melt-blown electrostatic electret process is that inorganic materials such as tourmaline and the like are added into polypropylene (PP) polymers in advance, then charges are carried on the melt-blown materials in a mode of one or more groups of corona discharge of needle electrode voltage of an electrostatic generator of 5-10KV before cloth rolling, air below a needle point generates corona ionization when high voltage is applied, local breakdown discharge is generated, current carriers are deposited on the surface of melt-blown cloth under the action of an electric field, and a part of the current carriers can penetrate into the surface layer and are captured by traps of electret master batches, so that the melt-blown cloth becomes an electret filter material.

Although meltblown fabrics have excellent filtering effect after electret action, the problems cannot be overcome in production practice.

First, the processing and transport processes result in a reduction in the electrostatic charge of the meltblown fabric. The loss is mainly reflected in various links of the melt-blown fabric such as coiling, packaging, transportation, carrying, roll feeding, uncoiling, hot melting and the like in the processing process, because a large amount of personnel participate in the operation, various devices are inevitably used in the whole process flow in order to ensure continuous production, the melt-blown fabric is repeatedly rubbed, tensioned and conveyed between a production line and the devices, and all the operations and the flows inevitably cause the reduction of electrostatic charge on the melt-blown fabric and the reduction of electrostatic potential.

Second, the static charge is reduced as a result of changes in the melt blown fabric storage conditions. Generally, the electrostatic potential on the surface of the melt-blown electret material is attenuated with the increase of the storage time, the electrostatic attenuation trends of the surface points of the material under different charging voltages are the same, the retention rates are not greatly different, and the electrostatic potential tends to be stable after 30 days. However, this stabilization is relative and leads to the electrostatic charge on the meltblown surface being lost in various ways as a result of interference from external uncertainties. Under the conditions of normal temperature and normal humidity, the PP melt-blown electret material has better charge storage stability, but when the melt-blown cloth is in a high-humidity environment, due to polar groups in water molecules, the compensation effect of anisotropic particles in the atmosphere on charges on fibers is realized, and a large amount of charges are lost. The charge decreases with increasing humidity and is faster and faster. Under the current storage and transportation conditions, the condition of large humidity change inevitably occurs in the daily storage and transportation of the meltblown fabric, which easily causes the filtration efficiency of the meltblown fabric to be greatly reduced.

Thirdly, the filtering effect caused by unqualified melt-blown fabric products is poor. The electret processor is a processing device specially designed for improving the filtering efficiency of a melt-blown non-woven fabric filtering material, and comprises three parts: generator host computer, step-up transformer and electret handle frame. The processor can be combined on a melt-blown production line for on-line processing or independently process melt-blown filter material finished products, and the filter efficiency of the material can be greatly improved after the high-pressure processing of the processor. The structure form of the electret processing frame can be customized according to the production field, and the whole set of equipment can meet the requirements of different widths and production line speeds of the filter material. However, in the actual production in the present stage of China, many meltblown fabric manufacturers are not provided with electret treatment equipment, because they mainly produce civil masks; a plurality of melt-blown fabric manufacturers produce melt-blown fabrics from other products, and do not know the process of electret treatment on the melt-blown fabrics used in the mask industry; and equipment of some enterprises is aged and does not reach the standard or the process design is defective, so that even if electret treatment is carried out, the high filtering efficiency is not achieved, and meanwhile, the filtering effect of the melt-blown fabric is greatly reduced. Under such circumstances, if the mask manufacturer purchases the melt-blown fabric which does not meet the standard, it is impossible to produce the mask which meets the standard.

Fourth, the charge amount is difficult to increase. Generally, increasing the meltblown charge can be done by electret treatment. The material composition and structure of the electret to facilitate charge retention is such that the static charge is stored until the charge is applied. The valid period of normal medical masks is six months to two years, while the valid period of some masks in Japan is three years, and the valid period of 3M masks can reach five years. There are two approaches to improving the charge storage capacity of electret materials: (1) the crystallinity and mechanical deformation of the material are improved, so that the structure of the material is changed, and a slender hole channel is formed to prevent charge drift. (2) Charge traps are created to trap charge by introducing additives with charge storage properties. For general mask manufacturers, both of the two methods are very difficult to adopt, because the two methods are measures for the melt-blown fabric manufacturers, and the mask manufacturers basically cannot improve the two methods, the purchased melt-blown fabric quality has the most important influence on the filtering quality of the mask. Once the quality of the melt-blown fabric is problematic, mask manufacturers are basically stranded.

In order to solve the above problems, a need exists in the market for a device for mask manufacturers to improve the filtering effect of masks simply and at low cost.

Disclosure of Invention

In order to solve the problems, the invention relates to a method for enhancing the filtering effect of a mask and the mask prepared by the method. By utilizing the method, the charges generated by the direct-current voltage discharge are implanted into the face mask to complete the electrostatic secondary charging of the face mask, thereby further enhancing the electrostatic adsorption function of the face mask or compensating the defect of the filtering effect caused by unqualified melt-blown cloth.

The specific technical scheme of the invention is as follows:

a method for enhancing the filtering effect of a mask is characterized in that an electrostatic generator is used for carrying out integral polarization treatment on materials of each layer of the mask from the front side of the mask under the condition of external voltage.

Before the process of jointing and forming each layer of the mask, the whole polarization treatment is carried out on each layer of the mask.

Preferably, the continuous mask body is subjected to a global polarization process prior to the process of cutting a plurality of continuous shaped mask bodies into individual mask bodies.

Preferably, the mask body is subjected to a whole polarization treatment before the mask bagging step.

Preferably, the method further comprises the step of carrying out integral polarization treatment on each layer of materials of the mask from the back surface of the mask.

Preferably, the mask shell fabric is made of polypropylene material.

Preferably, the external voltage is 20-50KV, the polarization treatment process time is 1-3s, and the distance of the polarization treatment is 10-25 mm.

Preferably, the applied voltage is 20-50KV, such as 20KV, 25KV, 30KV, 35 KV, 40 KV, 45 KV or 50KV, and the specific values therebetween are limited to the space and for the sake of brevity, and the present invention is not exhaustive of the specific values included in the range.

Preferably, the pitch of the poling process is 10-25mm, for example 10mm, 13mm, 16mm, 19mm, 22mm or 25mm, and the specific point values between the above point values, limited to space and for the sake of brevity, are not exhaustive of the invention to include the specific point values in the ranges.

Preferably, the polarization treatment process time is 1-3s, such as 1s, 1.5s, 2s, 2.5s, 3.0s, and the specific values therebetween are limited in space and for the sake of brevity, and the invention is not intended to be exhaustive of the specific values included in the ranges.

Preferably, the static electricity generating device comprises a shell, a bottom plate, a pressing roller arranged on the bottom plate, a grounding plate and a static bar, wherein a plurality of discharge holes are formed in the static bar, and a plurality of discharge needles are arranged on the discharge holes.

A mask with enhanced filtering effect at least comprises an outer protective layer, a middle melt-blown cloth layer and an inner contact layer; and carrying out integral polarization treatment on the materials of all layers of the mask from the front and/or the back by an electrostatic generator under the condition of external voltage.

Compared with the prior art, the invention has the following beneficial technical effects:

1. can effectually guarantee that each layer material is whole to have higher electrostatic potential when the gauze mask is leaving the factory, and the filter effect is outstanding. The invention is equivalent to that outside a melt-blown fabric manufacturer, the mask manufacturer polarizes the whole mask, so that all layers of the whole mask are charged, and compared with the condition that only melt-blown fabric is charged, the mask has more accumulated charges and more excellent filtering effect. The problem that the whole quality of the mask can only be guaranteed by the quality of the melt-blown cloth raw material product by mask manufacturers is solved, and the mask manufacturers can guarantee the quality of the mask by themselves.

2. The mask subjected to the additional integral polarization treatment has the advantages that the electrostatic potential is increased, the carrying charge amount is increased, the area of a charge spreading area is increased, the reduction speed of the integral charge carrying amount is objectively reduced, and the mask embodies better charge retention performance in storage and general operation.

3. The whole power-up process can be arranged before the mask is packaged at the latest, the mask filtering efficiency of the entering packaging bag is guaranteed to be at an excellent level, and after the packaging bag is packaged, the mask can be guaranteed to be at the optimal interval of the filtering efficiency for a long time due to the fact that water vapor enters the difficulty. The charge loss generated in the production, storage, transportation and processing of the melt-blown cloth can be effectively avoided, the charge carrying capacity is ensured, and the filtering efficiency is ensured.

4. The mask can be polarized using a higher voltage to achieve the desired amount of charge carrying. Research shows that the larger the charging voltage is, the larger the electric field intensity is, the larger the electrostatic potential on the surface of the filter material is, and the polypropylene melt-blown fabric has good electrostatic performance. However, the thickness of the meltblown for mask is very small, and if the charging voltage exceeds 10Kv, a spark discharge occurs and the material is broken down, so that the charging voltage should be carefully selected. In addition, some research papers used 20-60Kv for detection and evaluation of filtration efficiency, and did not actually consider the thickness of the experimental sample. But when the whole polarization of gauze mask was handled, because the increase of whole thickness, can use higher charging voltage to carry out polarization to the gauze mask, can be so that the electrostatic potential is higher, and the electric charge accumulation is more, and filtration efficiency is higher. Experiments prove that the aim of the invention can be completely achieved when the voltage is increased to 50Kv, and the processing time can be properly shortened under high voltage, thereby being beneficial to speed matching of electrostatic equipment and the whole production line.

5. On the production line using the method for enhancing the filtering effect of the mask, two static electricity generating devices can be used at the same time, one static electricity bar faces the front side of the mask, the other static electricity bar faces the back side of the mask, the whole mask is subjected to polarization treatment from the positive direction and the negative direction, the filtering efficiency is higher, and the speed of the production line can be matched better.

6. The raw material melt-blown cloth used for the mask is reduced in electrostatic adsorption effect due to unqualified quality or long-term storage, and can not meet the normal use requirement, secondary reinforcing polarization treatment can be carried out on the melt-blown cloth, even if the raw material is unqualified, the filter effect can be normally exerted through secondary treatment, the waste of the raw material can not be caused, and the method is particularly important for mask manufacturers in special periods.

7. Because the mask surface material is subjected to polarization treatment by using high-voltage discharge of more than 20Kv, the mask surface material has a good sterilization effect, when a civil mask is produced, the production efficiency of the mask can be effectively improved, an ultraviolet irradiation device is not required to be used for treating the mask, and the time is usually more than that of polarization treatment.

8. For a common two-layer disposable non-woven fabric mask, the common non-woven fabric material is adopted, so that the excellent electrostatic adsorption function cannot be achieved, and good electrets cannot be formed. However, since polypropylene is used as a raw material, the mask according to the present invention can be charged to a certain amount, and the filtering efficiency can be improved even in a state where the plastic bag is sealed and stored.

9. The method for enhancing the mask filtering effect of the invention uses the equipment principle basically consistent with that of the existing discharging equipment, only needs to adjust the placing position and the working parameters of the electrostatic discharging equipment according to the equipment on a specific production line, has low cost and simple operation, basically has no influence on the whole process flow, and is very beneficial to wide medium and small mask production plants.

10. In extreme cases, the method of the invention can also be used for reprocessing expired masks, so that the expired masks can be charged again and put into emergency use again, which is also important for mask manufacturers in special periods.

The method for increasing the filtering effect of the mask adopts a polarization treatment process, and improves the electrostatic adsorption function of the material by adjusting factors such as external voltage, polarization treatment time, polarization treatment distance and the like. The mask prepared by the method has the advantages that the filtering efficiency is improved to a great extent, and the highest filtering efficiency of the mask subjected to polarization treatment can reach 90%.

Drawings

FIG. 1 is a schematic perspective view of an electrostatic generator according to an embodiment;

in the figure:

1-a shell; 2-a bottom plate; 3-pressing roller; 4-a ground plane; 5-electrostatic rod.

Detailed Description

In order that the invention may be readily understood, a more particular description of the invention briefly described below,

it is to be understood that the terms "includes" and "including" as used in the specification and claims are open-ended terms that are intended to be interpreted as "including, but not limited to. The description which follows is a preferred embodiment of the invention, however, the description is given for the purpose of illustrating the general principles of the invention and not for the purpose of limiting the scope of the invention. The scope of the invention should be determined from the following claims.

Terms in the present invention

The 'polarization treatment process' in the invention means that an electrostatic treatment device is used for applying an external voltage to generate a large amount of charged charges through an electrostatic rod to be gathered near a discharge hole or a discharge needle and generate a certain potential difference with an earth plate so as to form an electric field, and when the mask fabric passes through the space between a compression roller and the earth plate, the charges generated by the external voltage are implanted into the mask fabric under the action of the electric field force so as to complete the electrostatic charging of the mask fabric.

The experimental materials used in the examples of the present invention and the comparative examples are as follows:

(1) non-woven fabrics: the nonwoven fabric used in the present invention is available from Shandonghua nonwoven fabric Co.

(2) Melt-spraying cloth: the melt-blown fabric used in the invention is purchased from Shandonghua non-woven fabrics Co.

(3) The masks prepared in the embodiment are all disposable emergency protective masks comprising an outer non-woven fabric layer, a melt-blown layer and an inner non-woven fabric layer.

Example 1

The embodiment provides a method for increasing the filtering effect of a mask, which comprises the steps of carrying out integral polarization treatment on each layer of material of the mask from the front side of the mask through an electrostatic generating device under the condition of applying voltage, and completing the integral polarization treatment and integral electrostatic charging on each layer of material of the mask before the step of jointing and forming each layer of material of the mask. The static generating device comprises a shell 1, a bottom plate 2, a press roller 3 arranged on the bottom plate, a grounding plate 4 and a static rod 5, wherein the static rod 5 is provided with a plurality of discharging holes.

In this embodiment, the electrostatic rods 5 are square rods, the number of the electrostatic rods is set to 2, and the casing pipes made of PVC material are wrapped outside the electrostatic rods. When the polarization treatment was carried out by applying a voltage, the applied voltage was set to 20KV, the polarization time was 3s, and the polarization pitch was 10 mm. The mask prepared by the method was subjected to a filtration test.

Example 2

The embodiment provides a method for increasing the filtering effect of a mask, which is characterized in that before a plurality of continuous formed mask main bodies are cut into single mask main bodies, electric charges generated by external voltage are implanted into non-woven fabric and melt-blown fabric of the mask main bodies to complete the whole static charging of the mask. The static generating device comprises a shell 1, a bottom plate 2, a press roller 3 arranged on the bottom plate, a grounding plate 4 and a static rod 5, wherein a plurality of discharge needles are arranged on the static rod 5. The meltblown fabric used has been electret treated by meltblown fabric manufacturers.

In this embodiment, the static stick 5 is the square stick, and 2 are set for to the quantity, and outside parcel one deck PVC material sleeve pipe. When the polarization treatment was carried out by applying a voltage, the applied voltage was set to 20KV, the polarization time was 3s, and the polarization pitch was 10 mm. The mask prepared by the method was subjected to a filtration test.

Example 3

The embodiment provides a method for increasing the filtering effect of a mask, which is characterized in that before the process of bagging the mask, an electrostatic generator is used for carrying out integral polarization treatment on a mask main body from the front side to complete electrostatic charging of the mask. The static generating device comprises a shell 1, a bottom plate 2, a press roller 3 arranged on the bottom plate, a grounding plate 4 and a static rod 5, wherein a plurality of discharge needles are arranged on the static rod 5. The selected mask melt-blown cloth raw material is not subjected to electret treatment.

In this embodiment, according to the electrostatic adsorption principle of the material, the non-woven fabric of this embodiment is made of polypropylene. The static stick 5 is the square stick, and 2 are set for to quantity, and outside parcel one deck PVC material sleeve pipe. When the polarization treatment was carried out by applying a voltage, the applied voltage was set to 20KV, the polarization time was 3s, and the polarization pitch was 10 mm. The mask prepared by the method was subjected to a filtration test.

Example 4

The present embodiment differs from embodiment 2 in that the conditions of the polarization treatment are replaced with: the applied voltage is 30KV, the polarization time is 2s, and the polarization distance is 15 mm.

Example 5

The present embodiment differs from embodiment 2 in that the conditions of the polarization treatment are replaced with: the applied voltage is 50KV, the polarization time is 1s, and the polarization distance is 25 mm.

Example 6

The present example is different from example 2 in that the electrostatic charging process was performed simultaneously on the mask layer materials from the front and back surfaces of the mask by the electrostatic generator.

Example 7

The difference between this example and example 2 is that the mask after electrostatic charging was packed in plastic bags normally, and left to stand at room temperature of 23 ℃ and humidity of 30% for 120 hours for further testing.

Comparative example 1

The civil disposable protective mask adopts the externally-adopted melt-blown fabric without electret treatment and does not polarize the whole mask.

Comparative example 2

The civil disposable protective mask adopts the melt-blown fabric for electret treatment, but the whole mask is not subjected to polarization treatment.

Comparative example 3

The comparison example is different from the example 1 in that the output voltage of the static electricity generating device connected with the high-voltage power supply is changed to 5KV, and other conditions are not changed.

Comparative example 4

The present example is different from example 1 in that the applied voltage of the polarization treatment was changed to 60KV, and other conditions were not changed.

Comparative example 5

This example differs from example 7 in that the mask after electrostatic charging was pretreated and left to stand at 38 ℃ and 30% humidity for 120 hours.

Comparative example 6

The difference between this example and example 7 is that the mask after electrostatic charging was pretreated and left to stand at 38 ℃ and 85% humidity for 120 hours.

And (3) testing the filtration performance:

(1) equipment: LZC-H type filtering efficiency tester

(2) The standard requires that: the filtration efficiency is tested according to a method specified by the standard of GB 19083-2010 medical protective mask technical requirement, and the gas flow is kept to be 85L/min stably during measurement.

The mask filtering effects provided by examples 1-7 and comparative examples 1-6 were tested according to the above method, and the test results are shown in table 1.

TABLE 1 filtration test results of examples and comparative examples

	Efficiency of filtration
		Example 1	80%
Example 2	87%
		Example 3	81%
Example 4	85%
		Example 5	83%
Example 6	88%
		Example 7	81%
Comparative example 1	30%
		Comparative example 2	75%
Comparative example 3	33%
		Comparative example 4	28%
Comparative example 5	81%
		Comparative example 6	54%

According to the comparison test results, compared with the mask which is not subjected to polarization treatment by melt-blown cloth, the mask prepared by the method for enhancing the filtering effect of the mask under various initial conditions has the advantage that the filtering efficiency is generally enhanced by about 50%; the embodiment using the discharge needles obtained better filtration efficiency than the embodiment using the discharge holes; when the charging voltage is in the interval of 20-50Kv, good filtering efficiency can be obtained; after the mask with normal charges is polarized and reinforced, the filtering efficiency is higher than that of the mask only subjected to qualified electret treatment on melt-blown cloth; after the mask which does not normally carry charges is polarized and reinforced, the filtering efficiency of the mask is not obviously reduced compared with the mask which is subjected to qualified electret treatment; the mask is polarized from the front direction and the back direction to obtain the highest filtering efficiency; after the mask after polarization treatment is placed for 120 hours under the normal humidity condition at room temperature, the filtration efficiency is reduced by no more than 10 percent; the filtration efficiency is reduced more when the filter is stored under the condition of 85% humidity. Generally, the mask prepared by the method has strong filtering efficiency improving performance and charge maintaining performance.

The applicant states that the present invention is illustrated by the above examples to show the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, i.e. it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims (10)

1. A method for enhancing the filtering effect of a mask is characterized in that the overall polarization treatment is carried out on each layer of material of the mask from the front side of the mask under the condition of external voltage through an electrostatic generating device.

2. The method of enhancing filtration through a mask of claim 1 wherein the mask layers are integrally polarized prior to the step of joining the mask layers together.

3. The method of enhancing mask filtration according to claim 1 wherein the continuous mask body is subjected to a global polarization process prior to the step of cutting a plurality of continuous shaped mask bodies into individual mask bodies.

4. The method of enhancing the filtration effectiveness of a mask of claim 1 wherein the mask body is subjected to a bulk polarization process prior to said mask bagging step.

5. The method of enhancing the filtration effectiveness of a respirator according to claim 1 further comprising the step of subjecting the individual layers of material of said respirator from the back side of said respirator to an integral polarization treatment.

6. The method of enhancing the filtration effectiveness of a respirator according to claim 1 wherein the respirator shell is a polypropylene material.

7. The method for enhancing the filtering effect of a mask according to claim 1, wherein said applied voltage is 20-50KV, said polarization treatment process time is 1-3s, and the interval of said polarization treatment is 10-25 mm.

8. The method for enhancing the filtering effect of the mask according to claim 1, wherein the static electricity generating means comprises a shell (1), a bottom plate (2), a pressure roller (3) disposed on the bottom plate (2), a grounding plate (4) and a static electricity bar (5) having a plurality of discharge holes.

9. The method of enhancing the filtering effect of a mask of claim 8 wherein said discharge holes are provided with a plurality of discharge needles.

10. A mask with enhanced filtering effect is characterized by at least comprising an outer protective layer, a middle melt-blown cloth layer and an inner contact layer; and carrying out integral polarization treatment on the materials of all layers of the mask from the front and/or the back by an electrostatic generator under the condition of external voltage.

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