JP3002154U - Air purification filter - Google Patents

Abstract

(57) [Summary] [Structure] The base fabric 2 has a flat surface 4 having a stitch 3 in which hexagons are continuously arranged adjacent to each other, and a loop-shaped pile 5 by connecting hexagonal vertices in a certain direction. An air purification filter in which a three-dimensional structure in which loop-shaped piles are projected to one side or both sides of a plane is formed by a knitting formed by forming the And an air purification filter in which the electret filter 7 is arranged in parallel with the plane of the base cloth. [Effect] The air purifying filter of the present invention is mainly used by incorporating it into an air conditioner mounted on an automobile and used as a filter. It has a low pressure loss, a high adsorption rate of malodorous gas, and a high-speed one-pass flow of air. Also has a large purification effect and can be used for a long time. Furthermore, if an electret filter is also used, dust and air in the air can be removed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an air purifying filter. More specifically, it is a filter that is mainly used by being incorporated in an air purifier for an air conditioner that is loaded on an automobile. It is an air purification filter that can obtain a high degree of purification even when flowing at high speed.

[0002]

[Prior art]

 In order to remove the bad odor in the air, a packed bed of activated carbon has been mainly used in the past, but the adsorption speed of malodorous substances is slow, so in order to improve this, use a small activated carbon particle size, or A thicker packed bed was used. However, with such a structure, the pressure loss increased, and when trying to secure a sufficient air volume, the noise of the fan became a problem. Japanese Unexamined Patent Publication (Kokai) No. 58-175560 discloses a low-pressure loss type air cleaning filter in which a honeycomb type sheet containing activated carbon and an electret filter are combined.

[0003] Furthermore, the one in which powdered activated carbon is supported by using urethane foam as a base material has a high initial activity but a high pressure loss, and the usable period of the filter is short because the amount of the activated carbon supported is small. The air purifying agent containing activated carbon fibers as a main component also has a shortcoming that the usable period is generally short because the amount of activated carbon retained is small. In order to prolong the usable period, it is necessary to increase the activated carbon packing density, and granular activated carbon is used. Therefore, the pressure loss becomes high and the noise of the blower becomes a problem.

There is also a method in which granular activated carbon is supported by using coarse knitting, but such a two-dimensional structure can only provide a filter having low pressure loss but low initial activity. In addition, there is no known one having a three-dimensional network structure other than urethane foam carrying activated carbon powder.

Particularly, unlike a household air purifier that purifies air by a circulation system, an air purifier mounted on a vehicle adopts a one-pass method in which the speed of introduced air is high when air is taken in from outside the vehicle. Therefore, even under such conditions, it is required to have a high degree of purification and a long service life with a low pressure loss. Furthermore, it is necessary to prevent the air purifying agent from falling off because it is used in a state of violent vibration.

Further, in order to remove airborne dust, an electrostatic air cleaner or an electrostatic precipitator has been conventionally used. In these devices, dust particles are charged by corona discharge, and the dust particles are collected and removed by electrodes or filters having opposite charges. However, due to corona discharge, a high voltage of several KV or several tens of KV is required to charge the dust particles, which is not only dangerous in handling but also may cause a fire.

Therefore, there is a strong demand for a dust collector that does not require a high voltage, and various filters that do not rely on the electrostatic effect have been proposed. However, the air inside a room or vehicle often contains cigarette smoke consisting of ultra-fine particles with a diameter of 1 μm or less, and a filter with a very high pressure loss is required to collect such dust. Was unavoidable. Therefore, with this method, it was extremely difficult to remove dust particles efficiently with low pressure loss.

[0008]

[Problems to be solved by the device]

 The present invention is mainly used as a filter for use in an air conditioner for an air conditioner mounted on an automobile, and it can be used for a long time at low pressure and can be used for a long period of time. It aims to develop and provide an air purification filter that does not cause the air purification agent to fall off even when used under vibration.

[0009]

[Means for Solving the Problems]

 The inventor of the present invention has a low pressure loss and long-term use as an air purifying filter, which is mainly used by incorporating it into an air purifier for an air conditioner mounted on an automobile, and is highly purified even when air is passed through at high speed in one pass. We have studied a filter that can obtain a high degree of accuracy and that does not cause the air purifier to fall off even when used in a violent vibration state. In this case, in order to be able to use for a long period of time and to achieve low pressure loss, it is necessary to use granular activated carbon that has a high packing density. Under these conditions, it is considered that the most effective way is to arrange granular activated carbon in a three-dimensional network structure and let air flow through it in a violently turbulent state to contact with activated carbon. Based on this, the present invention has been reached.

That is, the base fabric 2 has a flat surface 4 having a stitch 3 in which hexagons are continuously arranged adjacent to each other and a hexagonal vertex in a certain direction to form a loop-shaped pile 5. A three-dimensional structure in which loop-shaped piles are projected on one side or both sides of a plane in a knitted fabric consisting of parts, and an air purification filter in which activated carbon particles 6 are carried by a binder on the knitting yarn of the base cloth, and further an electret This is an air purification filter in which the filter 7 is arranged parallel to the plane of the base cloth.

The present invention will be described in detail below.

The base cloth of the air purifying filter of the present invention has a loop-shaped pie formed by connecting a flat surface 4 having a stitch 3 in which hexagons are continuously arranged adjacent to each other and a hexagonal vertex in a certain direction. It is necessary that the knitting be made up of the part where the rule 5 is formed. In order to make the air passing perpendicular to this plane into a violently turbulent state, it is necessary to increase the air velocity. Since the passage time of the filter consisting of one layer of base fabric is short, it is possible to use the air purification filter of the present invention by stacking a plurality of filters so that the planes of the filters are parallel to each other depending on the situation of use.

In addition, it is necessary that the entire surface of the base cloth is a stitch in which hexagons are continuously and adjacently arranged. Hexagonal stitches have been selected because of the shape stability of the base fabric and the uniform purification effect when air is passed through the stitches in which the activated carbon particles are supported on the knitting yarns. The size of the hexagonal stitches can be appropriately selected depending on the use conditions, but in the case of a filter for an air conditioner to be loaded on a vehicle, one side is preferably about 2 to 6 mm.

On the plane of the base fabric of the present invention, a loop-shaped pile 5 is formed by connecting hexagonal vertices on the plane in a certain direction, and the loop-shaped pile is extended to one side or both sides of the plane. The original structure is formed. The vertices of the hexagon may be connected by connecting the two vertices so as to pass through the center of the hexagon, or by connecting both ends of two adjacent sides of the hexagon. All of these lines connecting the vertices of the hexagon are parallel to each other when viewed in a certain direction, that is, the direction perpendicular to the plane. In addition, parallel here does not mean that it is limited to a strict horizontal line, but may be approximately parallel. In some cases, a certain deviation may rather disturb the air flow and significantly increase the Reynolds number. The base fabric needs to be a knitted fabric having such a three-dimensional structure.

In order to impart such a structural property to the knitted fabric, it is necessary to use a knitting yarn having a certain degree of rigidity. For example, a 100 to 200 denier monofilament such as nylon or polyester should be contained in the knitting yarn. When such a yarn is included, a stable three-dimensional structure of the knit is maintained. In addition, other ordinary thin yarns may be used together, and it is more preferable to use thin yarns together in order to firmly bond the activated carbon particles to the knitting yarn. Furthermore, the material of the base cloth is not limited to fibers, and any material that can have such a three-dimensional structure can be used, and for example, a knitted material woven with a thin aluminum wire may be used.

In the knitting yarn of the base fabric of the present invention, it is necessary that the activated carbon particles are adhered and supported by the binder. Activated carbon particles are components that have the purification function of the air purification filter element.

The activated carbon used here generally has a large surface area of several 100 m ² or more per 1 g, and can be used in a wide range as long as it is a carbon material exhibiting high adsorptivity. Activated carbon is a unique material with extremely excellent adsorptivity as a non-polar adsorbent, and exhibits high adsorptivity for almost all gaseous substances, and is particularly excellent in removing malodorous components. The raw material of activated carbon is usually charcoal such as coconut shell or wood, or coal, but either may be used. Further, the activation method may be obtained by steam or carbon dioxide at a high temperature or by any method such as treatment with zinc chloride, phosphoric acid or concentrated sulfuric acid.

In the present invention, the activated carbon supported on the knitting yarn of the base fabric is limited to the activated carbon particles in the sense that thin layer powdered activated carbon or activated carbon fiber which cannot be supported at a high packing density and a packed amount is excluded. is there. Therefore, the activated carbon particles also include particles such as crushed coal, granulated coal or granular coal. Granulated coal is prepared according to a conventional method by adding 30 to 60 parts of petroleum pitch or coal tar as a binder to 100 parts of carbon material, kneading, molding and activating.

The binder used here for adhering the activated carbon particles to the knitting yarn of the base fabric is not particularly limited. A wide range of adhesives such as emulsion, latex, solution adhesive, hot melt adhesive, etc. can be used. Among these, an adhesive is preferable in which the activated carbon particles are firmly adhered to the knitting yarn and the surface of the activated carbon other than the adhered portion is hardly covered. In addition, since there are considerable vibrations when loaded and used in automobiles, it is generally said that parts must withstand accelerations of 4 G or higher. If the activated carbon particles and the base cloth are misaligned due to vibration when they solidify after bonding and become highly rigid, the deformation may not be absorbed and the particles may fall off. Therefore, even when it is solidified after adhesion, an adhesive having a plasticity state, that is, an adhesive having tackiness is more preferable. For example, acrylic emulsion, latex, or hot-melt adhesive that remains sticky after solidification can hold activated carbon particles in the knitting yarn in the state of point adhesion, and also has plasticity after solidification, so there is a risk of particles falling off due to vibration. There is no and is more preferable.

Examples of emulsions include acrylic emulsions obtained by copolymerizing acrylic ester with acrylic acid and methacrylic acid ester, ethylene-vinyl acetate copolymer resin emulsions or vinyl acetate resin emulsions, and latexes. Various synthetic rubber latices such as chloroprene, nitrile rubber and SBR are used.

However, the emulsion or latex alone generally has a slightly low adhesive force, and when air is caused to flow into the gaps of the base fabric in a state of severe turbulence, the activated carbon particles carried on the knitting yarn may fall off. Therefore, in order to further increase the adhesive force between the knitting yarn of the base cloth and the activated carbon particles, an adhesive obtained by mixing polyvinyl alcohol with an acrylic emulsion having plasticity after solidification is more preferable, or a smaller amount of a crosslinking agent is added. May be added. Here, the mixing ratio of the polyvinyl alcohol solution and the acrylic emulsion is preferably in the range of 30:70 to 10:90. When polyvinyl alcohol is added to the acrylic emulsion, the adhesive strength is increased, and it becomes possible to carry several times as many activated carbon particles as when it is not added.

In order to support the activated carbon particles on the knitting yarn of the base fabric with an emulsion-type adhesive, the base fabric is dipped in the adhesive to sufficiently attach the adhesive to the knitting yarn, and the knitting yarn is pulled up with a steam blow. After clearing the clogging, sprinkle 20-40 mesh activated carbon particles and adhere to the knitting yarn. Furthermore, a filter element having a stable three-dimensional structure is obtained by firmly adhering it to the knitting yarn and, at the same time, performing steam treatment to remove excess particles and drying at 115 ° C. for about 3 hours.

Since the activated carbon supported by such a method is in a point-adhesive state, the decrease in adsorptivity is extremely small as compared with that before the supporting. For example, as shown in Example 1, the amount of benzene adsorbed on the activated carbon particles before loading was 42.3%, while it was 42.1% after loading, showing almost no decrease.

The hot melt adhesive generally comprises a polymer, a wax, a plasticizer, a thickener, an antioxidant, etc., but the main component polymer is an ethylene-vinyl acetate copolymer resin, an acrylic ester, etc. Acrylic copolymer resins, isobutylene polymers, isoprene polymers, polyamide resins, polyester resins, etc. are used. Among these, those containing styrene-isoprene copolymer or acrylic copolymer as the main component have high plasticity even after solidification and the activated carbon particles supported may fall off even if vibration of 4 G or more is applied. None more preferred. The hot-melt adhesive has a merit that it does not cover the surface of the activated carbon other than the bonded portion to a small extent, its adhesive strength is relatively high, and its work efficiency is high.

The method of adhering the activated carbon particles to the knitting yarn of the base cloth using the hot melt adhesive is almost the same as that of the emulsion type adhesive, and the base cloth is dipped in a molten hot melt adhesive to knit After sufficiently adhering the adhesive to the yarn, keep it at a high temperature and sprinkle 20 to 40 mesh of activated carbon particles to adhere it to the knitting yarn. By blowing high temperature air to remove excess activated carbon particles and then cooling, the particles can be firmly attached to the knitting yarn, and a filter having a stable structure can be obtained. In addition, the decrease in adsorptivity of activated carbon particles when supported by a hot-melt adhesive is almost the same as in the case of emulsion-based adhesives, but the degree of spot adhesion can be increased depending on the adhesive method. In some cases, it is possible to further reduce the decrease in adsorptivity.

The air purifying filter of the present invention may further include an electret filter. Here, the electret filter is a filter containing a substance in which a substance is electrically polarized, that is, a substance having a constant electrostatic charge at all times. Therefore, ultrafine particles, such as cigarette smoke, with a diameter of 1 μm or less, which are usually positively charged, are attracted to the negatively charged part of the electret filter. Therefore, the fine particles can be efficiently removed with a low pressure loss. Such ultrafine particles are difficult to remove by a normal filtration method, and pressure loss is unavoidably large.

The electret filter is usually made of a material that is polarized by an electret treatment to become a dielectric, for example, a polymer such as polyethylene, polypropylene, polyester, or polyvinyl fluoride. Various methods are known as permanent polarization methods. Usually, a dielectric is sandwiched between electrode plates, the temperature is raised to around the softening point, and the material is gradually cooled to room temperature with a high DC voltage applied. able to make. In addition, since this polarized state is maintained for several years, it has a function of removing ultrafine particles for a long period of time. Moreover, since it is not necessary to apply a high voltage when using it, it is easy to handle, there is no risk of fire, and safety is high.

The electret filter can be made of electret-treated fibers, non-woven fabrics, sheets, or the like. In the present invention, a coarse non-woven fabric with low pressure loss is subjected to electret treatment. When it is attached to the front surface of the above-mentioned activated carbon filter, it is possible to remove dust contained in the air and further the aerosol such as minute cigarette smoke.

The flat surface of the base fabric of the air purifying filter of the present invention has stitches in which hexagons are continuously arranged adjacent to each other, and a pile of loops connecting the hexagonal vertices on the flat surface is further formed. As a result of the construction of No. 5, a three-dimensional structure is formed in which the pile overhangs on one side or both sides of the plane. The looped pile connecting the vertices of the hexagon is created, so that even if air enters perpendicularly to the plane, it will collide with many obstacles before or after reaching the hexagonal stitch. It has become. Moreover, since the filter has a knitted structure as a whole, the cross-sectional area of the air flow passage is quite large, so the pressure loss is low, and when flowing at high speed, the air flows in a violent turbulent flow inside the filter. Become.

For example, when an air purifying filter is installed inside a transparent plastic tube and a large number of linear smoke flows at high speed, it is recognized that the air is flowing in a turbulent flow inside the filter. . Therefore, it can be seen that the adsorption rate of malodorous gas is extremely high and the pressure loss is low. It is considered that this is because the air flows in a violent turbulent flow and the cross-sectional area of the flow passage is quite large. In the case of air conditioner elements mounted on automobiles, the pressure loss can be adjusted to 5 to 20 Pa or less at an air linear velocity of 1 m / sec.

Since the malodorous gas is adsorbed at a high rate, almost all the malodorous gas is adsorbed until just before the amount of adsorption reaches saturation. Further, since the air purification element of the present invention is made to carry activated carbon particles as much as possible, it can be used for a long period of time.

By further using the electret non-woven fabric together with the air purification element, it is possible to remove dust contained in the air, finer aerosols, and the like.

[0033]

【Example】

 Hereinafter, the present invention will be described more specifically with reference to examples.

(Example 1, Comparative Example 1) As a base fabric, a nylon monofilament of 140 denier and a polyester yarn of 40 count were mixed to form a hexagonal flat layer stitch having a side of 3 mm by spun knitting. A 4mm high loop pile was driven in to create a three-dimensional knit.

Dip in 20 parts of polyvinyl alcohol using the above-mentioned base cloth as a binder, 80 parts of acrylic acid-acrylic acid ester copolymer emulsion (solid content ratio), sufficiently attach the emulsion to the knitting yarn and pull it up to steam. After removing the clogging of the stitches by blowing, 30-40 mesh activated carbon particles were sprinkled to adhere to the knitting yarn. Furthermore, steam treatment was performed to firmly adhere to the knitting yarns and at the same time remove excess particles, and dried at 115 ° C. for about 3 hours to obtain an air purification filter having a stable three-dimensional structure (Example 1). ).

FIG. 1 (a) shows an isometric view of the filter obtained above. In addition, in order to clarify the three-dimensional structure in (b), the isometric view of only the base cloth is also shown.

The air purifying filter 1 is a loop formed by connecting a flat surface 4 having a stitch 3 in which hexagons are continuously and continuously arranged on the entire surface of the base fabric 2 and a vertex passing through the center of the hexagon in a certain direction. It is a knitted fabric made up of the pile-shaped piles 5. In addition, it has a three-dimensional structure with a loop-shaped pile overhanging on one side of the plane.

The activated carbon particles 6 are carried by the binder on the hexagonal stitches 3 on the plane 4 and the loop-shaped pile 5.

[0039] Here, the basis weight of knitted and activated carbon particles of the base fabric of the air cleaning filter is respectively 360 g / m ² and 1400 g / m ^2, pressure loss of air is 20 ° C., the linear velocity of 1 m / sec at 1 atmosphere At that time, it was 6.2 Pa. The adsorption amount of benzene before and after loading of activated carbon particles on the base fabric was 42.3% and 42.1% respectively, and the adsorption amount of benzene was knitting yarn made of acrylic acid-acrylic acid ester copolymer emulsion with polyvinyl alcohol added. Almost no decrease due to loading on the.

Next, in order to examine the deodorizing property of the air purification filter described above, a filter with a size of 200 × 200 × 5 mm was installed at a position 4 m from the inlet side of a wind tunnel with a cross-sectional size of 200 × 200 mm and a length of 6 m, and contains toluene. The relationship between the flow time and the toluene content at the outlet of the wind tunnel was investigated when a gas with an amount of 80 ppm was flowed at a relative humidity of 65%, 20 ° C, a linear velocity of 1 m / sec, and a flow rate of 144 m ³ / hr. In addition, when the vibration was maintained for 4 hours under the vibration of 4G, the activated carbon particles did not fall off at all.

For comparison, the same test was carried out using a sheet of polyurethane foam carrying powdered activated carbon (Comparative Example 1). Table 1 shows the filter weight, the amount of activated carbon supported and the pressure loss of the air purifying filter and the powdered activated carbon-supporting polyurethane sheet of the present invention, and Fig. 2 shows the relationship between the flow time and the toluene content at the outlet of the wind tunnel.

[0042]

[Table 1]

As a result, it can be seen that the air purification filter of the present invention has a high adsorption rate and a large amount of activated carbon, and thus has a long usable period and a low pressure loss.

(Example 2) A 100-denier polyester monofilament and a 40th polyester thread were mixed as a base fabric, and the flat layer hexagon was 4 mm on a side and the height of a loop pile was 5 mm. A knitted fabric with a three-dimensional structure in which piles are projected on both sides of the base cloth plane was created.

In addition to the main component polyamide resin as a binder, a hot melt adhesive containing a wax, a plasticizer, a thickener, and an antioxidant is used as the base cloth, and the base cloth is applied to the molten hot melt adhesive. After immersing and adhering it to the knitting yarn of the base fabric and blowing it with heated air to remove the clogging of the knitted fabric, the activated carbon particles of 20 to 30 mesh were carried by substantially the same operation as in Example 1.

Further, the electret-treated coarse polypropylene nonwoven fabric having a low pressure loss was attached to the front surface of the base fabric carrying the activated carbon prepared above to prepare an air purification filter. FIG. 3 shows a cross-sectional view of the filter obtained above.

Since the activated carbon particles of the air purification filter thus obtained are firmly held by the knitting yarn, the activated carbon particles were kept for 24 hours in a vibration state with an acceleration of 6G, but the activated carbon particles were completely removed. I couldn't do it.

Further, the adsorption of purple smoke of cigarette by the electret filter was recognized. In addition, the decrease in the adsorptivity of activated carbon and the pressure loss due to the loading on the knitting yarn were almost the same as those of the air purification filter element of Example 1.

[0049]

[Effect of device]

 The air purifying filter of the present invention is mainly used by incorporating it into an air conditioner mounted on an automobile for use as a filter. It has a low pressure loss, a high adsorption speed of malodorous gas, and a high-speed one-pass cleaning. It has a great effect and can be used for a long time. Furthermore, if an electret filter is also used, dust and air in the air can be removed.

[Brief description of drawings]

FIG. 1 (a) is a perspective view of an embodiment of an air purification filter of the present invention. A perspective view of the base fabric of the filter is shown in (b).

FIG. 2 shows a relationship between a circulation time when a toluene-containing gas is passed through an air purification filter and a toluene content after the passage.

FIG. 3 is a sectional view showing another embodiment of the air purification filter of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air purification filter 2 Base cloth 3 Hexagonal stitches of base cloth 4 Flat surface of base cloth 5 Loop pile 6 Activated carbon particles 7 Electret filter 8 Example 1 9 Comparative example 1

Claims (4)

[Scope of utility model registration request] 1. The base fabric 2 has a loop-shaped pile 5 formed by connecting hexagonal vertices in a certain direction with a plane 4 having a stitch 3 in which hexagons are continuously arranged adjacent to each other. An air purification filter which is a knitted fabric consisting of parts, in which a three-dimensional structure in which loop piles are projected to one side of a plane is formed, and activated carbon particles 6 are supported by a knitting yarn of the base cloth by a binder. 2. The base cloth 2 is formed by forming a loop-shaped pile 5 by connecting a hexagonal vertex in a certain direction with a plane 4 having a stitch 3 in which hexagons are continuously arranged adjacent to each other on the entire surface. An air purification filter in which a three-dimensional structure in which loop-shaped piles are projected on both sides of a plane is formed by a knitting consisting of parts, and activated carbon particles 6 are carried on a knitting yarn of the base cloth by a binder. 3. The base cloth 2 is formed by forming a loop-shaped pile 5 by connecting a flat surface 4 having a stitch 3 in which hexagons are continuously arranged adjacently to each other and a hexagonal vertex in a certain direction. In the knitting consisting of parts, a three-dimensional structure in which a loop-shaped pile is projected to one side of the plane is formed, and the activated carbon particles 6 are carried on the knitting yarn of the base cloth by a binder, and the electret filter 7 is parallel to the plane of the base cloth. Air purification filter that is placed in. 4. The base cloth 2 has a plane 4 having a stitch 3 in which hexagons are continuously arranged adjacent to each other on the entire surface, and loop-shaped piles 5 are formed by connecting hexagonal vertices in a certain direction. In the knitting consisting of parts, a three-dimensional structure in which loop-shaped piles are projected on both sides of the plane is formed, and activated carbon particles 6 are carried by the binder on the knitting yarn of the base cloth, and the electret filter 7 is parallel to the plane of the base cloth. Air purification filter that is placed in.