KR20070069236A - Electrostatic air filter and method for manufacturing of the same - Google Patents

Abstract

An electrostatic air filter which maintains high fine dust collecting efficiency and low pressure loss characteristics, prevents multiplication and growth of bacteria, and can maximize the productivity as compared with conventional air filters, and a method for manufacturing the same are provided. An electrostatic air filter comprises a static electricity applied polymer film manufactured in the form of densely aggregated tubes, and a fine irregular structure formed on an inner or outer wall of the polymer film. A method for manufacturing an electrostatic air filter comprises the steps of: adding an antibacterial agent to two flat polymer films; grinding the surface of the polymer films to form an irregular depression-and-protrusion structure; applying a static electricity to the polymer films; folding one of the polymer films in a waveform or sawtooth-shape; adhering the folded polymer film and the flat polymer films to each other by an adhesion means to form the polymer films in the form of densely aggregated tubes; and cutting the polymer films in the form of densely aggregated tubes by a heating wire, and stacking the cut polymer films.

Description

Electrostatic air filter and its manufacturing method {Electrostatic air filter and method for manufacturing of the same}

1 is a perspective view showing the structure of an electrostatic air filter according to the present invention.

2 is a block diagram showing a method of manufacturing an electrostatic air filter according to the present invention.

Figure 3 is a block diagram showing the bending molding of the electrostatic air filter according to the present invention.

<Description of the symbols for the main parts of the drawings>

10 electrostatic air filter 11 polymer film

12: TUBE 13: Lower gear roll

14: rolling roll 15: cutting device

The present invention relates to an electrostatic air filter and a method of manufacturing the same, and more particularly, the surface layer of fine irregularities and fine fibers having irregularities on the one or both sides of the polymer film to which the antibacterial function is added and having a depth of 1 μm or more (lower). After forming the electrostatics, the static electricity is added, and one or two or more polymer films to which the static electricity is applied are manufactured in the form of a dense tube, thereby achieving higher fine dust collection efficiency and lower pressure loss characteristics than conventional air filters. The present invention relates to an electrostatic air filter and a method of manufacturing the same, which can prevent the growth and growth of bacteria and maximize productivity.

In general, the increase of air pollution by industrial development and urbanization has caused serious pollution of indoor and outdoor air, and air filters are used to purify the polluted air.

The air filter is used in cold heaters, air purifiers, automobiles, and the like, and is mainly composed of nonwoven fabrics, and the nonwoven filter includes devices such as sieving, interception, impact, or diffusion. The dust in the air is collected and filtered.

Air filters made of simple nonwoven fabrics are widely used in various applications because of their simple manufacturing process and low cost.

However, the nonwoven air filter has a disadvantage in that the filtration efficiency of dust is deteriorated, and in particular, the ability to collect fine dust having a size of 2.5 μm or less harmful to a human body is inferior.

In order to filter the fine dust, the fiber density of the nonwoven fabric must be increased in order to narrow the space between the nonwoven fabrics, but in this case, the excessively high density of fibers prevents the circulation of air through the air filter, resulting in excessively large pressure loss. Triggered.

Therefore, in the case of such a non-woven air filter, a separate blowing mechanism forcibly passing air must be used to secure an adequate amount of ventilation for air purification, and the air filter can be used according to the pressure loss of the air filter. The size and capacity of the blower are determined, which leads to the loss of energy and the enlargement of the air purifier.

Among the shortcomings of the nonwoven air filter, an air filter using a nonwoven fabric having an electrostatic charge added thereto has been developed to compensate for fine dust collection efficiency.

The electrostatic nonwoven air filter is manufactured by adding an electrostatic charge during fabrication of a fabric for manufacturing a melt blowing nonwoven fabric or by non-woven fabrication after the fibrous polymer film to which the electrostatic charge is added is produced. The nonwoven air filter In addition to the collection mechanism of the addition of the electrostatic force collecting mechanism has the advantage that the filtration efficiency is greatly improved.

However, the pressure loss was not greatly improved due to the characteristics of the nonwoven fabric itself, and in particular, the nonwoven fabric with the electrostatic charge alone was difficult to maintain the shape of the product. There is a problem that a greater air resistance or pressure loss is caused when passing through the air filter.

Therefore, the air filter using the nonwoven fabric as described above can be operated if it can be used by using a forced blower, but can only involve energy loss due to pressure loss, and only a separate natural blower or a small blower If this is available, the injection rate of air will drop and it will not be possible to purify a sufficient amount of air.

Another type of air purifier is an electrostatic air purifier that removes dust by adding charge to dust and filters.

Electrostatic precipitating air purifiers in which dust is collected by applying electrostatic force to the dust collecting plate by applying electric charge to the dust through corona discharge are mainly composed of a plate-like structure with a large gap between the dust collecting plates.

Therefore, since the air flows into the air purifier freely, pressure loss is greatly improved, and dust collection efficiency is also excellent.

However, a separate external voltage is required for corona discharge to add charge to dust and the voltage addition of the dust collector plate, and an appropriate electric circuit must be configured. Therefore, the apparatus is enlarged rather than simply purifying air using only a filter. There is also a disadvantage in price.

In addition, since external power is required for air purification, energy costs are also increased.

As a method of simultaneously obtaining the advantages of a simple filter type air purifier and an excellent air permeability electrostatic air purifier, an air filter using a polymer film having an electrostatic charge added instead of a nonwoven fabric has been proposed.

The polymer film-type air filter is configured such that dust is collected in the polymer film to which the static charge is added while the air containing the dust passes between the polymer film separated by a suitable spacer or a tubular structure made of the polymer film. As a result, the pressure loss is greatly improved compared to the non-woven type air filter, and there is an advantage in that a sufficient amount of air can be purified even without a separate blower or a very small blower.

In the case of the polymer film-type air filter, when dust adheres to the surface of the film, and when a dust layer having a predetermined thickness is formed, the collecting capacity is reduced, so that the surface area of the filter must be wide to collect a large amount of dust.

Therefore, in general, a simple polymer film type air filter has a disadvantage in that the collecting capacity of the filter is lowered because the surface area is smaller than that of the nonwoven air filter.

In addition, since it is difficult to expect the removal of dust by the sieving, the static charge should be added uniformly and properly.

In addition, since the film surface has a trapping capacity, in order to reduce pressure loss, if the diameter of the tubular structure is too large or the distance between the films is too large, the dust passing through the center of the pipe may approach the wall of the filter. There is a problem that the chance to lose the opportunity to just escape without being trapped in the filter, there is a problem to lose the low pressure loss, which is an inherent advantage of the polymer film-type air filter in order to reduce the size of the tube.

In order to solve this problem, the electrostatic air filter has been recently developed by increasing the surface area by forming fine irregularities of uniform shape on the surface of the polymer film to which the electrostatic charge is added, thereby increasing the surface area.

The surface-treated film-type air filter has excellent air permeability and excellent filtration ability of fine dust, compared to the non-woven air filter, but the method of forming the surface irregularities used for manufacturing the electrostatic air filter has a slow processing speed. This has the disadvantage of lowering the productivity.

In addition, in order to increase the surface area, the surface irregularities should have a large aspect ratio, but it is difficult to manufacture an air filter in which the surface area is increased to improve the fine dust collecting ability by the conventional method.

Vortex formation of air-containing fluid inside the tube has a structure close to the shape of the inner wall of the tube. Vortex is more easily generated when irregularities are formed on the surface, especially when the irregularities and irregularities on the surface If fine fibers are formed, a greater effect can be expected.

In addition, in the case of the conventional air filter to which the electrostatic charge is added, irregularities and electrostatic charge functions are provided only on one side of the polymer film, and in the space formed of the surface on which the unevenness and the electrostatic charge function are not provided on the opposite side, There is a problem that the dust collection capacity is significantly reduced.

On the other hand, various types of air filters are commercially available, but after a certain period of use, bacteria in the air multiply in the air filters, causing contamination and odors in the surroundings, and may be harmful to the human body.

In order to solve this problem, products have been introduced that have a technology of suppressing germ propagation by forming an air filter in a multi-layered structure, but this type of air filter has a low productivity due to the multi-step manufacturing process. There is a limit to prevent the growth of bacteria.

The present invention has been made in view of the above, the polymer film to which the electrostatic charge is added is manufactured in the form of a dense tube, to form a fine concavo-convex structure on the inner wall or inner wall and outer wall of the polymer film to increase the surface area and inside the tube By inducing the flow of air passing through the vortices, it increases the probability of access to the dust contained in the air and the polymer film to which the static electricity is added to improve the collection efficiency, and the air can pass compared to the cross-sectional area of the filter By maximizing the size of the space, air resistance, that is, pressure loss can be minimized to ensure breathability even in natural ventilation conditions, and by adding an antimicrobial agent to the polymer film, the antimicrobial fundamentally suppresses the growth and growth of bacteria on the filter surface. It is an object of the present invention to provide an electrostatic air filter and a method of manufacturing the same that ensure a function.

The present invention for achieving the above object in the electrostatic air filter,

The polymer film to which the static charge is added is manufactured in the form of a dense tube, and a fine concavo-convex structure is formed on the inner wall or the inner wall and the outer wall of the polymer film.

In a preferred embodiment, the concave-convex structure is irregularly formed in a straight surface structure, characterized in that it forms a right angle or a constant angle with respect to the traveling direction of the pipe (the traveling direction of the air passing through the filter).

In a more preferred embodiment, the surface of the irregularities formed in the polymer film is characterized by having a fine fiber layer.

In addition, the polymer film is characterized in that the non-polar polymer of any one selected from polyethylene, polypropylene and polytetrafluoroethylene or a mixture thereof as a raw material.

In addition, the polymer film is characterized in that the addition of 0.05 to 1.0% by weight of the antimicrobial agent.

In addition, the antimicrobial agent is characterized in that any one selected from polyhexamethylene mono guanidine chloride, polyhexamethylene mono guanidine phosphate and polyhexamethylene mono guanidine organic acid salt.

Moreover, in the manufacturing method of an electrostatic air filter,

Adding an antimicrobial agent to the two flat polymer films; Surface polishing to form irregular concave-convex structures on the surface of the polymer film; Adding a static charge to the polymer film; Bending one of the polymer films into a wave shape or a sawtooth shape; Adhering the bent polymer film and the flat polymer film by means of bonding so that the polymer film is densely formed in a tubular shape; Cutting and stacking the dense tubular polymer film by hot wire; Characterized in that comprises a.

In addition, the polymer film is characterized in that both sheets are bonded after bending.

In addition, the polymer film is characterized by being bent by a combination of gear rolls.

In addition, the temperature of the hot wire is characterized in that 100 ~ 150 ℃.

In addition, the adhesive means is characterized in that any one selected from fusion welding, hot melt adhesive use and high frequency welding.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing the structure of an electrostatic air filter according to the present invention, FIG. 2 is a block diagram showing a method of manufacturing an electrostatic air filter according to the present invention, and FIG. 3 is a bending molding of the electrostatic air filter according to the present invention. It is a device block diagram which shows.

The present invention relates to a filter for collecting and removing dust contained in air, in particular, an electrostatic air filter for removing dust by adding static electricity to a material.

The present invention focuses on the fact that the polymer film 11 to which the electrostatic charge is added is manufactured in a dense tubular form, and a fine uneven structure is formed on the inner wall or inner wall and outer wall of the tubular polymer film.

Electrostatic air filter 10 of the present invention is a form in which the polymer film 11 having an electrostatic charge and irregular micro-concave-convex structure on the surface form a dense tube shape, the fine concavo-convex structure of the surface of the tube 12 is the traveling direction of the tube 12 That is, it forms an angle or 30 degrees or more with respect to the advancing direction of the air which passes through a filter.

The fine concavo-convex structure of the surface is linear, providing the effect of widening the surface area that can adsorb fine dust, and at the same time inducing the vortex formation of air passing through the pipe to improve the purification efficiency of fine dust.

In addition, in order to maximize the effect of widening the surface area, the larger the aspect ratio of the concave-convex structure is, the more advantageous, preferably, a value of 1 or more.

Irregular uneven surface formed on the film has a fine fiber layer can further maximize the dust collection efficiency and dust collection amount of the fine dust present in the air passing through the tube.

The polymer film 11 is generally manufactured using a nonpolar polymer such as polyethylene, polypropylene or polytetrafluoroethylene or a mixture thereof as a raw material. However, a small amount of polar polymer or a small amount of the polymer is required for the addition of static charge and maintenance of surface charge during use. Fatty acids or fluorinated compounds can be added during film production.

Antimicrobial agents Polyhexamethylene monoguanidine chloride, polyhexamethylene mono guanidine phosphate, polyhexamethylene mono guanidine organic It is good to finally add 0.05 to 1.0% by weight of these antimicrobial agents when preparing the polymer film 11 by adding 10% master chip by adding an acid salt or the like.

This is because when the antimicrobial agent is used at 0.05 wt% or less, the antimicrobial activity is lowered, and when the antimicrobial agent is used in excess of 1.0 wt%, the antimicrobial activity is enhanced, but discoloration of the film may occur.

The fine irregularities of irregular shapes and fine fiber layers formed on the irregularities effective in the practice of the present invention are the surface polishing of the polymer film and the film processing using the rolls having the surface processed in the form of needles or the like. You can get it.

Abrasives are largely divided into non-woven abrasives and abrasive abrasives. Non-woven abrasives are products that are usually produced by irregularly adhering abrasives of a desired size using an adhesive to a nylon-based nonwoven fabric, and are mainly used to increase the smoothness of the processed surface by cushioning the nonwoven fabric.

In addition, since fine burrs that may be generated by the nonwoven fabric are removed, the generation of secondary burrs in the polishing process is suppressed.

An abrasive grain is an adhesive having a uniform particle diameter attached to a surface formed of a paper or a similar material by coating or the like, and has an advantage of forming surface irregularities having a desired depth and shape. May damage the base metal.

In addition, abrasive abrasives can make a fine secondary burr on the surface of the base material, but the secondary burrs formed through the abrasive abrasives are not fixed burrs. It can be a depressing factor.

After secondary burr processing, the surface of the film may be needle scratched to form a larger amount of burr.

Methods of adding electrostatic charges to polymer moldings (polymer films) 11 in the form of films or nonwovens are already known in the US patent.

In general, a method of inducing permanent polarization by using a strong electric field in a heated state of the polymer film 11 or using corona discharge treatment or electrified water droplets is known. When corona discharge treatment or an electric field is used, an appropriate level of charging effect is obtained. For this purpose, it is necessary to add a voltage of ± 5 kV or more from the polymer film 11 within a predetermined interval or to form an electric field corresponding thereto.

The charged polymer film may be bent into a wavy or serrated or corrugated form and then molded into a compact tube 12.

Specifically, the polymer film 11 may be processed using a combination of gears adjusted to an appropriate temperature or may be bent in a wave or saw form using a flat bending press, and then two or more bent films or one sheet may be bent. When the film and one flat film are adhered by a method such as heat fusion, hot melt adhesive, or high frequency welding, a dual structure film in which the tube 12 formed of the polymer film 11 is continuously formed can be obtained.

After cutting the double-structured film to a certain length and then laminating and cutting it to an appropriate size using a heating wire, it is possible to produce a dense tube-shaped air filter.

At this time, the adhesion between the laminated double-layer film is automatically made by heat fusion at the heat wire passing portion in the cutting process using the hot wire.

In this process, if the temperature of the hot wire is too high, the polymer film is excessively melted at the portion passing through the hot wire, and the molten resin blocks the air filter vent.

In addition, if the temperature of the hot wire is too low, the film is pressed with an excessively strong force at the time of cutting the film laminate to obtain a product whose aperture size is smaller than the designed value.

Therefore, in order to obtain an air filter having a beautiful appearance and a vent having a designed size, the temperature of the hot wire must be properly adjusted, and specifically, 100 to 500 ° C is preferable.

In addition to manufacturing the electrostatic air filter 10 having a laminated structure, it is possible to manufacture the electrostatic air filter 10 even by simply winding a bent film or a dual structure film formed by bonding two or more films together, and the dense tube 12 Although several methods for the production of a) form are illustrated above, the scope of application of the present invention is not limited by the method of forming such a laminated structure.

Example

Hereinafter, an embodiment of a method of manufacturing an electrostatic air filter according to the present invention will be described. At this time, the material of the polymer film 11 to be used is a polypropylene film, the thickness of the film to be used is 75 ~ 90㎛, the voltage at the time of static charge addition is DC 10 ~ 25kV.

1) Polishing process: A process of polishing a polymer film 11 made for an electrostatic filter with a given tension, and forming a pattern of irregularities along with minute irregularities on the surface. (Reference: Abrasive Particle Size + Polishing Material Scratch Plain Group Depth + Average Pc: Peak count

A polishing roll made by adhering or coating an abrasive composed of abrasive particles having a thickness of 40 μm on both sides of the fabric horizontally in the direction of fabric progression is mounted on the roll, and fine irregularities are formed on both sides of the high molecular film 11 by using the polishing roll. In the same way as the direction of the fabric, unevenness of about 1㎛ depth is manufactured while keeping the density of 100Pc or more and 20Pc or more densities of 5㎛ or more. (Peak count: Number of irregularities more than the designated size per 1cm, called the size specified here Means having a depth deviation of 1 μm or more)

After forming a fine concavo-convex pattern, a polishing roll made by adhering or coating an abrasive composed of abrasive particles of 120 μm to a roll is mounted, and the concave-convex is formed by the same method as mentioned above using the polishing roll. The size of the unevenness produced is more than 100㎛ for the size of 5㎛ or more, 20Pc or more for 20㎛ or more.

After the grinding process, fine dust or fiber may be generated. If the clean roll made by pressing an artificial air blower or a microfiber wiper is installed on both sides at the end of the polishing process and applied under strong pressure, fine dust or fiber is passed. Is removed and this fine dust or fiber is installed for continuity of work in such a way that it is removed again by an adhesive system on top of the clean roll.

Then, to form a fine fiber on the surface of the uneven film, the surface of the film is processed while rotating at a speed faster than the film feed rate by using a needle or similar roll or processed in a similar form, the surface of the uneven film New burr-like fine fibers are created that are not removed in a coercive manner.

The scratch-type concave-convex pattern having the fine fibers thus formed maximizes the surface area of the polymer film 11 to increase the dust collecting ability, and has a great effect in increasing the electrostatic effect by impairing the air flow during pore formation.

2) Add a static charge: While maintaining the height of the patterned polymer film 11 to 10 ~ 25mm, add a voltage of about 10 ~ 25kV + pole at the bottom,-pole at the top.

In this case, tungsten wire, tungsten pin, and metal are used at the upper end, and the lower end is used after the insulating coating treatment with ceramic on the metal plate. At this time, the ceramic coating is suitable about 30 ~ 200㎛, when thicker than this may be a problem in the durability of the DC supply device because the insulation is too high.

When the voltage is added, the polymer film 11 is in close contact with the lower plate of the ceramic plate coated with ceramic and is transported at a low speed. The polymer film 11 produced for the electrostatic filter by strong corona discharge has a directivity of charge. do.

3) Bending molding of the film: Each gear of the lower gear roll 13 artificially moves the polymer film 11 by using a gear roll mold in which the polymer films 11 having artificially electrical properties are processed in a semi-circular shape. It is forcibly put in the interspace, and the product shape is preserved in the secondary gear roll to prevent the desorption of the product in the product transfer from the rolling roll 14 to laminating.

In order to prevent the desorption of the product, the lower gear roll 13 should be maintained at a temperature of about 40 degrees. If the temperature is high, it may affect the characteristics of the product, so that the polymer film 11 is not desorbed. Adjust the temperature between 60 degrees.

The higher the temperature, the higher the adhesiveness of the polymer film 11 can increase the process speed. In the case of the polymer film 11, hot melt of 0.1 to 0.2 mm diameter is continuously coated in the longitudinal direction at intervals of 2 to 3 mm on the upper surface of the polymer film 11 while undergoing a hot melt process. Laminating is performed with the polymer film 11 that is bent and advanced in the form inserted between the gears of the lower gear roll 13.

The polymer film 11 that is laminated as described above forms a laminated film structure, and is cut to a predetermined size by the cutting device 15 to be automatically laminated to the lamination device 16.

When the laminated film is cut by the cutting device 15 using the heating wire of FIG. 3, the polymer film 11 is instantaneously melted by heat, and the melt of the polymer film 11 flows downward by gravity. As the molten upper film moves along with the hot wire wire, instantaneous adhesion is performed with the molten lower film.

Ni-Cr wire is most suitable as the heating wire, and the diameter of the heating wire is 0.2-0.5 mm. The MFI value of the polypropylene film is 5 or less in order to prevent the melt from flowing downwardly at the time of melting the film.

Therefore, as a nonwoven fabric or paper type abrasive, a pattern having fine irregularities is formed on the surface of the film fabric, and a pattern having a non-woven fabric or paper type abrasive having a different particle size is applied to the film having the fine surface irregularities. It maximizes dust collection surface and gives fluidity of air flow.

When the surface of the film is processed by using a roll processed or surface-treated into a needle or a similar form having irregular surface irregularities, fine fiber-like burrs are generated.

Here, the size of the needle or the like processed or surface-treated form is 10 ~ 40㎛ and distributed irregularly. This is to prevent the film from tearing locally by making deep grooves concentrated on one surface of the film.

In addition, when the product is finally produced, the rate of change of air flow can be further increased, and a DC dust of 10 to 25 kV can be added to both sides of the film to make the film have a polarized static charge, thereby increasing the fine dust collecting effect. In addition, energy efficiency can be improved by minimizing the capacity of the fan used in the forced air purifying method by minimizing the pressure loss affecting the air flow.

As described above, according to the electrostatic air filter according to the present invention and a method for manufacturing the same, a non-woven fabric or a paper-type abrasive material having a different particle size is formed on the film fabric surface with a fine concavo-convex pattern. Pattern is used to maximize the dust collection surface area and the flowability of air flow when passing through the air, and the voltage is added to both sides of the film and the film has a polarized electrostatic charge to increase the effect of collecting fine dust. It can improve the energy efficiency by minimizing the pressure loss affecting the flow of air and minimizing the capacity of the fan used in the forced air purification method.

Claims (11)

In the electrostatic air filter, Electrostatic air filter, characterized in that the polymer film (11) to which the electrostatic charge is added is made in the form of a dense tube, and a fine concavo-convex structure is formed on the inner wall or the inner wall and the outer wall of the polymer film. The method of claim 1, wherein the concave-convex structure is irregularly formed in a straight surface structure, characterized in that it forms a right angle or a constant angle with respect to the traveling direction of the pipe 12 (the advancing direction of air passing through the filter). Electrostatic Air Filter. The electrostatic air filter according to claim 1 or 2, wherein the uneven surface formed on the polymer film has a fine fiber layer. The electrostatic air filter according to claim 1 or 2, wherein the polymer film is made of a nonpolar polymer selected from polyethylene, polypropylene, and polytetrafluoroethylene, or a mixture thereof. The electrostatic air filter according to claim 1 or 2, wherein an antimicrobial agent is added to the polymer film at 0.05 to 1.0% by weight. The electrostatic air filter according to claim 1 or 2, wherein the antimicrobial agent is any one selected from polyhexamethylene mono guanidine chloride, polyhexamethylene mono guanidine phosphate, and polyhexamethylene mono guanidine organic acid salt. In the manufacturing method of the electrostatic air filter, Adding an antimicrobial agent to the two flat polymer films; Surface polishing to form irregular concave-convex structures on the surface of the polymer film; Adding a static charge to the polymer film; Bending one of the polymer films into a wave shape or a sawtooth shape; Adhering the bent polymer film and the flat polymer film by means of bonding so that the polymer film is densely formed in a tubular shape; Cutting and stacking the dense tubular polymer film by hot wire; Method for producing an electrostatic air filter, characterized in that comprises a. The method of claim 7, wherein the polymer film is bonded after bending both sheets. The method of claim 7 or 8, wherein the polymer film is formed by bending a combination of gear rolls. The method of claim 7, wherein the temperature of the hot wire is 100 ~ 150 ℃. The method of claim 7, wherein the adhesive means is any one selected from young fusion welding, hot melt adhesive use, and high frequency welding.

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