KR101823915B1 - Method for preparing air purifying filter impregnated with cellulose and/or powdered activated-carbon - Google Patents

Abstract

The present invention relates to a method of manufacturing an air purification filter using a nonwoven fabric, made of synthetic fiber and including gaps, as support. More specifically, the method includes: a process of coating the nonwoven fabric with a hydrophilic coating agent; and at least one among a cellulose impregnation process of impregnating the gaps with cellulose mixed with water by filling the gaps with the cellulose and then freezing and drying the cellulose and a powdered activated-carbon impregnation process of impregnating the gaps with powdered activated-carbon mixed with a solution, which is made by dissolving a binder in a hydrophilic volatile organic solvent, by filling the gaps with the powdered activated-carbon and then drying the powdered activated-carbon at a preset temperature.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for preparing an air purifying filter impregnated with cellulose and / or powdered activated carbon,

The present invention relates to a method of manufacturing an air filter. More particularly, the present invention relates to a method for producing an air filter having excellent ultrafine particle filtration and / or volatile organic compound removal effect, in which at least one of cellulose and powdered activated carbon is impregnated between voids of nonwoven fabric fibers.

As urbanization and industrialization become more widespread due to the development of industry, automobile exhaust gas and factory soot have influence not only on residential indoor living space but also on multi use facilities such as tunnels, subway history, theaters and the like, It has become a social issue and has become a national concern. Furthermore, the frequency of dust and pollutants from the mainland is increasingly shifting to the Korean peninsula, and air pollution due to fine dust is accelerating throughout the Republic of Korea.

The problem of fine dust in Korea is also being shown by NASA, and recently, it has been announced that the exhaust gas of the coal base thermal power plant built in the west coast area is accelerating the fine dust concentration over the Korean peninsula . As a result, the government has ceased construction plans for thermal power plants in the future. In addition to strengthening regulations on exhaust gas emissions from automobiles and factories, it will soon be possible to regulate nonflammable emissions from cooking at large restaurants. Will be included.

On the other hand, a state in which particulate matter (PM, Particle Matter) floats in the air is generally called an aerosol, and is usually called dust. The particle size range of the dust is about 0.001 to 1,000 μm. However, since the dust of 50 μm or more is precipitated immediately upon occurrence, the suspended dust having a particle size of 50 μm or less is generally referred to as TSP (Total Suspended Particulates).

Particulate matter, not only solid particles but also liquid particles, is dispersed in the above dust. Particularly, when the particle size is 10 μm or more, the effect on the aesthetics of the city is affected. However, The environmental standard was changed to PM10 (below 10μm size) dust standard. Korea first applied the PM10 (micrometer / 1 μm for 1 millionth of a meter) to the environmental standard of the Environmental Policy Act of 1995 and added 'PM' for 2015, adding ' Have been used.

Such fine dusts have a great influence on skin-related diseases such as cold, respiratory diseases such as phosphorus, laryngitis, micro bronchitis, and atopic dermatitis. Accordingly, various air purifiers for purifying the air have been rapidly spreading in various buildings, industrial sites and homes, and it has become common practice to wear a fine dust mask when performing outside activities.

As a part of the above fine dust removing method, a nonwoven fabric filter fabricated by cutting a nonwoven felt has been used. However, the nonwoven fabric filter can be applied only as a prefilter having a size of 10 μm or more. Recently, PM10, which is the ultrafine dust of the smaller size, is difficult to remove and it is difficult to remove volatile organic compounds such as BTEX [benzene, toluene, ethylbenzene, xylene] Is more impossible.

In order to overcome the limit of the fine dust removing ability of the conventional nonwoven filter, the present inventors have tried to trap fine dust while keeping the air permeability by filling the porosity between the fibers of the nonwoven filter with a porous material, Is filled with an adsorbent material to remove the volatile organic compound, thereby completing the present invention.

An object of the present invention is to provide a method of manufacturing an air purification filter capable of removing fine dust while maintaining air permeability.

It is another object of the present invention to provide a method of manufacturing an air purification filter capable of removing volatile organic compounds.

It is still another object of the present invention to provide a method of manufacturing an air purifying filter capable of removing fine dust and volatile organic compounds while maintaining air permeability.

The above and other objects of the present invention can be achieved by the present invention described below.

The present invention relates to a process for producing an air filter using a non-woven fabric formed of synthetic fibers and having voids as a support, comprising the steps of coating the non-woven fabric with a hydrophilic coating agent and filling cellulose between water and the voids, A cellulosic impregnation process for impregnating the cellulose between the voids by vacuum drying, a powdered activated carbon blended with a solution in which a binder is dissolved in a hydrophilic volatile organic solvent is filled between the voids and then dried at a predetermined temperature, And a powdered activated carbon impregnation process for impregnating the voids with the powdery activated carbon.

In the present invention, it is preferable to further perform the cellulose impregnation process after the powdered activated carbon impregnation process.

In the present invention, the synthetic fibers may be composed of at least one compound selected from polypropylene, polyethylene and polyester.

In the present invention, the hydrophilic coating agent is preferably a coating agent containing silicon or titanium.

In the present invention, the freezing / vacuum drying temperature is preferably about -70 to -90 占 폚.

In the present invention, the amount of cellulose impregnated (mg) per unit area (cm 2) of the nonwoven fabric after the cellulose impregnation process is preferably about 4 to 6 mg / cm 2.

In the present invention, the volatile organic solvent having hydrophilicity is preferably methanol.

In the present invention, the predetermined temperature is preferably about 80 캜 to 130 캜.

In the present invention, it is preferable that the nonwoven fabric after the powdered activated carbon impregnation step has a powdered activated carbon impregnation amount (mg) per unit area (cm 2) of about 40 to 50 mg / cm 2.

INDUSTRIAL APPLICABILITY The present invention has the effects of the present invention, which provides a method for manufacturing an air purifying filter capable of removing fine dust, volatile organic compounds, or all of them, while maintaining air permeability.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flow chart showing a manufacturing method of an air purifying filter impregnated with cellulose;
2 is a flow chart showing a method of manufacturing an air purifying filter impregnated with powdered activated carbon.
3 is a flow chart showing a method of manufacturing an air purifying filter impregnated with powdered activated carbon and cellulose.
Fig. 4 is a graph showing the results of the removal of fine dust and BTEX while the fine dust and the BTEX-containing contaminated air pass through the nonwoven fabric, the air purifying filter impregnated with cellulose, the air purifying filter impregnated with powdered activated carbon and the air activated filter impregnated with powdered activated carbon and cellulose Fig.

The present invention relates to a manufacturing method of an air purification filter capable of trapping fine dust while filling a space between fibers of a nonwoven fabric filter with a porous material and trapping minute dust while filling the space between the pores with an adsorbent material to remove volatile organic compounds .

The overall process of the method of manufacturing the air purifying filter according to the preferred embodiment of the present invention will be outlined as follows.

The present invention relates to a process for producing an air filter using a non-woven fabric formed of synthetic fibers as a support, comprising the steps of: coating the non-woven fabric with a hydrophilic coating agent as shown in Figs. 1 and 2; A cellulose impregnation process in which cellulose is filled between the pores and frozen and vacuum-dried to impregnate the cellulose between the pores, and powdered activated carbon blended with a solution in which a binder is dissolved in a volatile organic solvent having hydrophilicity A powdered activated carbon impregnation process of filling the gap between the pores and drying the powder at a predetermined temperature to impregnate the powdered activated carbon in the pores.

Generally, the nonwoven fabric is produced by laminating filaments such as synthetic fibers such as polypropylene, polyethylene, and poly-ester, repeatedly combing and uniformly spreading the fibers, and forming a chemical synthetic binder Injected, and compressed. The nonwoven fabric formed of synthetic fibers is excellent in the connection between the fibers and the fibers, and pores are formed between the fibers, thereby forming a scaffold itself, so that a separate support is not required.

Synthetic fiber nonwoven fabric is a polymer material, and most of the hydrophobic nonwoven fabric is hydrophobic. Therefore, in order to easily place the cellulose and / or powdered activated carbon between the pores of the hydrophobic nonwoven fabric formed of synthetic fibers, a process of converting the nonwoven fabric into hydrophilic is required. Therefore, a process of coating a nonwoven fabric with a coating material containing silicon or titanium having a hydrophilic group (OH-) is first carried out. For example, the coating process is not particularly limited, but a coating, deposition, spraying, or the like method can be used. Thereafter, the hydrophilic film is fixed to the nonwoven fabric through a drying process.

Cellulose refers to cellulose microfibrils extracted from mulberry leaves, rice straw, cotton, trees and plants as natural polymeric materials. Cellulose is a hydrophilic substance that is very swellable in water but has the disadvantage that it hardens due to components such as pectin and lignine in the cellulose and hardly softens due to heat drying and decreases in size.

Therefore, in order to impregnate the cellulose with the voids between the nonwoven fabrics, it is necessary to maintain the expanded initial outer shape and shrinkage of the size when containing water even after drying, and at the same time to maintain the flexibility. To this end, the present invention relates to a method for producing a cellulose-based film, which comprises the steps of filling cellulose between water and a pore of a non-woven fabric after coating a non-woven fabric with a hydrophilic coating agent, and then freezing and vacuum drying the cellulose to impregnate the cellulose between the pores .

In this case, the cellulose that has been expanded with moisture is allowed to settle between the nonwoven fabrics by further expansion (expansion) during the freezing process and can be seated between the nonwoven fabrics without being deformed by sublimation in the drying process using vacuum have. Further, the cellulose that is seated between the nonwoven fabrics in the expanded state has an advantage that it is not lost even after the air filter is manufactured.

As an example of an optimum mixing ratio for easily impregnating cellulose fibers between non-woven fabrics coated with a hydrophilic coating agent, about 0.5 to 1.5 g of dry cellulose pulverized in about 1 liter of water is put into a nonwoven fabric having a size of 15 cm x 15 cm . Then, it is quenched at -70 캜 to -90 캜 and dried by vacuum. The preferred temperature is about -75 캜 to -85 캜, and more preferably about -80 캜. At this time, the cellulose impregnated amount (mg) per unit area (cm 2) of the nonwoven fabric is about 4 to 6 mg / cm 2. Preferably about 4.5 to 5.5 mg / cm2, and more preferably about 5 mg / cm2.

On the other hand, in order to impregnate the nonwoven fabric with the powdered activated carbon, which is a porous material used for the purpose of removing volatile organic compounds, a binder for binding the activated carbon powder and the nonwoven fabric is required, and a solvent for dissolving the binder is also required do. However, most of the organic solvents are adsorbed on the pores of the activated carbon, blocking the pores, and thus, there is a problem that the adsorption ability of the volatile organic compounds is lost.

Accordingly, after the step of coating the nonwoven fabric with the hydrophilic coating agent, the present invention is characterized in that the powdered activated carbon blended with a solution in which a binder is dissolved in a volatile organic solvent having hydrophilic property is filled between the pores of the nonwoven fabric, A powdered activated carbon impregnation process is performed to impregnate the voids with the powdered activated carbon.

As the volatile organic solvent having hydrophilicity, methanol is preferably used.

Methanol is not only adsorbed on hydrophobic active carbon pores but also hydrophilic materials as well as the daily use of the binder. In addition, since methanol is volatilized when dried at about 80 ° C to 130 ° C, preferably about 90 ° C to 110 ° C, more preferably about 100 ° C, only the powdered activated carbon remains between the nonwoven fabrics . Further, when dried at the above-mentioned temperature, all the pores of the activated carbon are opened, and the powdered activated carbon maintains the original specific surface area.

As an example of an optimum mixing ratio for easily impregnating powdered activated carbon between nonwoven fabrics, about 8 to 12 g of powdered activated carbon (particle size: 200 mesh or less) is added to about 1 liter of methanol, and polyvinyl acetate PVA) is injected into the non-woven fabric. When the impregnated nonwoven fabric is dried in a drying oven at about 100 ° C., all the methanol is volatilized and only the powdered activated carbon remains between the nonwoven fabrics. At this time, the activated carbon impregnation amount (mg) per unit area (cm 2) of the nonwoven fabric is about 40 to 50 mg / cm 2. Preferably about 42 to 48 mg / cm2, and more preferably about 45 mg / cm2.

Meanwhile, as shown in FIG. 3, a cellulose impregnation process may be further performed after the powdered activated carbon impregnation process to produce an air purifying filter for simultaneously removing ultrafine dust and volatile organic compounds.

Specifically, after the powdered activated carbon impregnation process, the cellulose compounded with water is further filled between the pores of the nonwoven fabric, followed by freezing and vacuum drying to impregnate the cellulose between the pores of the nonwoven fabric. In the case of powdered activated carbon and cellulose-impregnated nonwoven fabric, it is possible to remove ultrafine dust having finer size than cellulose-impregnated nonwoven fabric.

Hereinafter, an apparatus for removing fine dust and volatile organic compounds using an air filter according to the present invention will be described in detail with reference to the accompanying drawings. Fig. 4 is a graph showing the relationship between the amount of fine dust and the amount of BTEX removed while the contaminated air containing fine dust and BTEX passes through a nonwoven fabric, an air cleaning filter impregnated with cellulose, an air cleaning filter impregnated with powdered activated carbon, and an air cleaning filter impregnated with cellulose and powdered activated carbon Fig.

Conventional air pollutants are composed of PM10, PM2.5 and volatile organic compound BTEX, which are dust particles of 10 ㎛ in size or more, ultrafine dusts as described above, and the filters are arranged in the following order .

  The particulate matter having a size of 10 μm or more was removed using a conventional nonwoven fabric, and PM10 was subjected to a cellulose-impregnated air cleaning filter, PM2.5 and volatile organic compounds were impregnated with cellulosic and powdered activated carbon filters, And the volatile organic compound, which is a gaseous substance which is not removed in the powdered activated carbon impregnated air purifying filter, was removed with a powder activated carbon impregnated air purifying filter.

The present invention can be better understood by the following examples, and the following examples are for illustrative purposes only and the scope of protection of the present invention is not limited by the examples.

[ Example ]

Example  1: cellulose Impregnation  Air purification filter

A hydrophilic coating agent was applied to a 15 cm 2 x 5 mm nonwoven fabric made of synthetic fibers to make a hydrophilic nonwoven fabric. A cellulose solution containing about 1 g of cellulose and about 1 g of water was impregnated into the hydrophilic nonwoven fabric, Vacuum drying was performed to prepare a cellulose impregnated air filter. Cellulose used was pulverized cellulose pulp for the production of Korean paper. The fabricated cellulose-impregnated air filter had a cellulosic impregnation amount (mg) of about 5 mg / cm 2 per unit area (cm 2) of the nonwoven fabric.

Example  2: Powder activated carbon Impregnation  Air purification filter

A hydrophilic coating agent was applied to a 15 cm x 5 mm nonwoven fabric made of synthetic fibers to prepare a hydrophilic nonwoven fabric. An activated carbon solution containing about 5 g of polyvinyl acetate and about 10 g of powdered activated carbon mixed with about 1 liter of methanol was impregnated into the hydrophilic nonwoven fabric , And dried at about 100 DEG C to prepare a powder activated carbon impregnated air purifying filter. Powdered activated carbon passed through a 200 mesh sieve was used as the activated carbon. The prepared powder activated carbon impregnated air filter had a powdered activated carbon impregnated amount (mg) of about 45 mg / cm 2 per unit area (㎠) of nonwoven fabric.

Example  3: Activated carbon powder and cellulose Impregnation  Air purification filter

A cellulose solution containing about 1 g of cellulose and about 1 g of water was impregnated with the powdered activated carbon impregnated air filter prepared in Example 2, and the powdered activated carbon and cellulose impregnated air filter were prepared by freezing and vacuum drying at about -80 캜 Respectively.

Comparative Example  One

General non-woven fabric having a product name of 11280 ST-110W (dryer) manufactured by SAMSUNG nonwoven fabric was used.

Test Example  One

The PM10 and PM2.5 fine dusts were injected at a diluted concentration by mixing the standard JIS standard dust and the BTX mixture gas at a rate of 50 ppm in a 30 atm bomb with air mixed with air. The contaminated inflow air was conveyed using a blower, the size of the nonwoven fabric was 15 cm x 15 cm, and the thickness was about 5 mm, and the linear velocity (m 3 / ㎡ sec) of each nonwoven fabric was constantly operated at 2 m / sec.

Table 1 below shows experimental results comparing the PM10 size ultrafine dust removal efficiency of the cellulose-impregnated air purifying filter manufactured according to Example 1 and the general nonwoven fabric of Comparative Example 1. Conventional general nonwoven fabrics show very low removal efficiency of 11% to 39% due to the large pores between the nonwoven fabrics, but more than 97% in the case of the cellulose impregnated air filter.

Driving time
(time)
Non-woven
Cellulose impregnated air purification filter
Inflow dust concentration (PM10.ug / m3)
Outlet dust concentration (PM10.ug / m3)
Removal efficiency (%)
Inflow dust concentration (PM10.ug / m3)
Outlet dust concentration (PM10.ug / m3)
Removal efficiency (%) 0.5 950 850 11 850 20 98 1.0 980 780 20 780 15 98 1.5 860 740 14 740 23 97 2.0 940 680 28 680 12 98 2.5 980 660 33 660 15 98 3.0 970 590 39 590 12 98 3.5 880 585 34 585 11 98

Table 2 below shows the results of experiments on the removal efficiency of BTEX which is PM2.5 sized ultrafine dust and volatile organic compound of powder activated carbon and cellulose impregnated air purifying filter manufactured according to Example 3. The efficiency of ultrafine dust removal and The BTEX removal efficiency is 97% or more, and when the powder activated carbon impregnated air cleaning filter manufactured according to Example 2 is additionally installed to remove the BTEX that has not been removed, We can confirm excellence.

Driving time
(time)
Powder Activated Carbon and Cellulose Impregnated Air Filter
Powder activated carbon impregnated air purification filter
inflow
Dust concentration
(PM2.5 占 퐂 / m3)
Effluent dust concentration
(PM2.5 占 퐂 / m3)
Removal efficiency
(%)
inflow
(BTEX.ppm)
outflow
(BTEX.ppm)
Average
remove
efficiency
(%)
inflow
(BTEX.ppm)
outflow
(BTEX.ppm)
Average
remove
efficiency
(%) 0.5 580 21 96 B: 25
T: 23
E: 25
X: 23 B: 0.6
T: 0.2
E: 0.1
X: 0.3 99 B: 0.6
T: 0.2
E: 0.1
X: 0.3 B: 0.001
T: 0.002
E: 0.002
X: 0.002 99 1.0 620 12 98 B: 24
T: 25
E: 22
X: 25 B: 0.4
T: 0.2
E: 0.1
X: 0.1 99 B: 0.4
T: 0.2
E: 0.1
X: 0.1 B: 0.002
T: 0.001
E: 0.001
X: 0.001 99 1.5 610 15 98 B: 23
T: 22
E: 25
X: 26 B: 0.5
T: 0.3
E: 0.3
X: 0.1 99 B: 0.5
T: 0.3
E: 0.3
X: 0.1 B: 0.003
T: 0.001
E: 0.002
X: 0.001 99 2.0 580 16 97 B: 24
T: 25
E: 24
X: 23 B: 0.4
T: 0.2
E: 0.1
X: 0.1 99 B: 0.4
T: 0.2
E: 0.1
X: 0.1 B: 0.001
T: 0.002
E: 0.001
X: 0.001 99 2.5 610 18 97 B: 23
T: 25
E: 23
X: 21 B: 0.5
T: 0.3
E: 0.3
X: 0.2 99 B: 0.5
T: 0.3
E: 0.3
X: 0.2 B: 0.001
T: 0.001
E: 0.002
X: 0.001 99 3.0 590 12 98 B: 25
T: 23
E: 21
X: 22 B: 0.4
T: 0.2
E: 0.1
X: 0.1 99 B: 0.4
T: 0.2
E: 0.1
X: 0.1 B: 0.001
T: 0.002
E: 0.001
X: 0.002 99 3.5 585 15 97 B: 25
T: 23
E: 25
X: 23 B: 0.3
T: 0.1
E: 0.2
X: 0.1 99 B: 0.3
T: 0.1
E: 0.2
X: 0.1 B: 0.003
T: 0.001
E: 0.002
X: 0.001 99

(B: benzene, T: toluene, E: ethylbenzene, X: xylene)

Test Example  2

The specific surface area of the powdery activated carbon and the powdery activated carbon in the powdery activated carbon impregnated air filter manufactured according to Example 2 was measured and compared.

Table 3 below shows the specific surface area of the powdered activated carbon after drying in the drying furnace at 100 ° C and the raw powdery activated carbon. The specific surface area indicating the adsorption capacity was recovered to the activated carbon level even after the binder (PVA) was injected .

Powder activated carbon Specific surface area (m 2 / g, based on BET) Raw powder activated carbon 980 Raw material activated carbon + Methanol + PVA 100 ℃ drying 955

Claims (9)

1. A method of manufacturing an air purification filter using a nonwoven fabric formed of synthetic fibers and having voids as a support,
Coating the nonwoven fabric with a hydrophilic coating agent;
A powdered activated carbon impregnation process in which powdered activated carbon blended with a solution in which a binder is dissolved in a volatile organic solvent having hydrophilic properties is filled between the voids and then dried at a predetermined temperature to impregnate the voids with the powdered activated carbon; And
And a cellulose impregnating step of filling the space between the pores with water after the powdered activated carbon impregnation step and then freezing and vacuum drying the impregnated cellulose to impregnate the spaces between the pores. The method according to claim 1, wherein the synthetic fibers are made of at least one compound selected from the group consisting of polypropylene, polyethylene, and polyester. The method of claim 1, wherein the hydrophilic coating agent is a coating agent containing silicon or titanium. The method according to claim 1, wherein the freezing and vacuum drying temperature is from -70 ° C to -90 ° C. The method according to claim 1, wherein the nonwoven fabric after the cellulose impregnation step has a cellulosic impregnation amount (mg) per unit area (cm 2) of 4 to 6 mg / cm 2. The method according to claim 1, wherein the hydrophilic volatile organic solvent is methanol. The method according to claim 1, wherein the predetermined temperature is 80 ° C to 130 ° C. The method according to claim 1, wherein the nonwoven fabric after the powdered activated carbon impregnation step has a powdered activated carbon impregnated amount (mg) per unit area (cm 2) of 40 to 50 mg / cm 2. delete

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