KR20030007010A - Filter for electric fan and the method for preparation thereof - Google Patents

Abstract

PURPOSE: To provide a filter for an electric fan that is inexpensive, has high yield of non-woven fabric, can be used regardless of size of a blade guard, and has an increased dust collecting effect. CONSTITUTION: The non-woven fabric 16 is rectangular, so that the non-woven fabric 16 can be easily manufactured easily with high yield by cutting a band- like non-woven fabric, and the cost is reduced. Flat rubber bands 17 and 18 are loosely inserted into band insert parts 20 and 21 of the non-woven fabric 16, so that the non-woven fabric 16 can uniformly and sufficiently cover the entire guard regardless of the size of the blade guard 15, and tightness of a back surface part 15A by the filter 10 for the electric fan is increased and the dust collecting effect is also increased. Many gathers are produced at ends of the non-woven fabric 16 covering the inner periphery with a small diameter of the blade guard 15. The gathers increases the tightness of the non-woven fabric 16, and a collecting area is also increased by a gather forming part of the entire non-woven fabric 16. As a result, the dust collecting effect is further increased.

Description

Fan filter and manufacturing method thereof {FILTER FOR ELECTRIC FAN AND THE METHOD FOR PREPARATION THEREOF}

The present invention relates to a fan filter and a method for manufacturing the same, and in particular, a fan filter and a method for manufacturing the fan mounted on a wing guard covering the rotary blades of the fan.

In recent years, the fan filter which coats the wing guard which covers the rotating blade of a fan from the outside, and maintains this state and uses a fan has developed the filter for electric fans which filters the fine dust and dust floating in the indoor air.

As a filter for a conventional fan, for example, "a filter which takes dust and dust of a fan" of JP-A-11-159499 is known.

This conventional filter has a shape in which a portion of the donut shape is cut in a radial direction along the radial direction in a developed state, and can cover the back portion of the wing guard fixed to the motor portion of the fan, and the outer edge portion of the filter material. It is provided with one flat rubber band of the elastic material enclosed in the side, and the surface fastener which fits the both ends of the filter material wound by the said wing guard.

When using this conventional filter, the back part of a wing guard is first coat | covered with a filter material. In other words, the outer outer edge side of the filter material should follow the maximum diameter portion of the wing guard, that is, the connecting portion of the front portion and the rear portion of the wing guard, and the inner edge side of the filter material should follow the connection portion with the motor portion of the wing guard. This filter material is wound around the wing guard. Then, both ends of the filter material are sandwiched with a removable tape to maintain this winding state.

When the rotary blade is rotated by the motor unit, the air in the room is sucked into the inner space of the wing guard from the rear part of the wing guard, and then blown from the front part of the wing guard to the front of the fan. At this time, fine dust and dust floating in the indoor air are filtered by the filter material.

However, such a conventional fan filter has the following problems.

(1) In other words, the filter material had a substantially donut shape in a developed state. Therefore, in order to cut out the expanded filter material, a wide filter paper is required, the raw material cost is increased, and also a lot of fine grains are produced, and the yield of the filter material obtainable from the filter paper per unit area was low.

(2) In addition, when the flat rubber band is sealed to the outer edge of the filter material, for example, in the case of the nonwoven fabric or the woven fabric of which the filter material has a small elasticity, the maximum extension length of the flat rubber band is almost limited to the length of the filter material. It was. Therefore, fans of various sizes have been shipped to the market, and it is difficult to use a fan filter for a large fan exceeding the length of the filter material, and there is a fear that the filter will be damaged if forced.

(3) Moreover, the internal combustion part of the conventional filter material remained only cut at the time of cutting. Therefore, it was difficult to seal the connection part of a wing guard and a motor part without a gap by the inner edge part of a filter material. In particular, since the handle which protruded upward was formed in the back part of the normal wing guard, it was difficult to seal this handle part. As a result, indoor air containing dust and dust not filtered out of this gap was sucked into the wing guard.

(4) Further, even when a large-sized filter material is attached to a small fan, since the filter material is fan-shaped, the opening on the motor part side also becomes large, so that the state attached to the wing guard is unnatural and there is a problem in appearance.

Therefore, the present invention has a low raw material cost, high yield of nonwoven fabric, can be used regardless of the size of the wing guard, and also many dusts formed on the nonwoven fabric have a dust collecting effect, in particular, sealing property of the connection portion between the wing guard and the motor part. It aims at providing the fan filter and its manufacturing method which increase dust collection effect by raising.

In addition, an object of the present invention is to provide an electric fan filter capable of increasing the number of times of repeated use of the fitting member, and which can securely fix the nonwoven fabric to the wing guard by using the wire of the wing guard.

1

It is a perspective view of the use condition of the fan filter which concerns on one Example of this invention.

2

A plan view of a fan filter according to an embodiment of the present invention.

3

In the manufacturing method of the fan filter which concerns on one Embodiment of this invention, it is a perspective view which shows the cutting process of a nonwoven fabric.

[Description of the code]

10 Fan Filters

11 fans

12 motor

13 rotating wing

14 wire rod

15 wing guard

15A back

16 nonwovens

17, 18 plain rubber band (elastic band)

19 hook (fitting member)

20, 21 band guide

The invention as set forth in claim 1 covers the rotary blades fixed to the output shaft of the fan of the fan from the outside, and is attached to both edges of the non-woven fabric and an almost rectangular nonwoven fabric capable of covering the rear part of the wing guard having several wire rods. A fan filter comprising a pair of elastic bands of stretchable free material and a fitting member for maintaining a covering state of a back portion of a wing guard by the nonwoven fabric,

The pair of tubular band guides which inject each elastic band over almost the entire length of each of the peripheral edges of the long side of the nonwoven fabric is disposed, and the lengths of both elastic bands are described above. At the same time as the short side of the nonwoven fabric, the length of the elastic band inserted into the band guide portion on the motor side is shorter than the elastic band on the front portion side of the wing guard, and the fitting members are disposed on both ends of each elastic band. A fan filter.

Each size of the wing guard of a fan used, specifically, the diameter of a wing guard, the length along the radial direction from the inner periphery to the outer periphery of a wing guard, the diameter of a motor part, etc. are not limited.

In addition, the kind of nonwoven fabric is not limited. For example, in addition to dust in the air caused by air pollution, a nonwoven fabric having a mesh capable of efficiently collecting pollen and the like is preferable. The nonwoven fabric may be, for example, a nonwoven fabric made of natural fibers such as cotton, hemp, silk, or a nonwoven fabric made of various synthetic fibers such as propylene resin fiber, polyester resin fiber, and polyethylene resin fiber. Moreover, what solidified the nonwoven fabric with synthetic resin may be sufficient.

Moreover, you may print arbitrary shapes, arbitrary figures, arbitrary pictures, etc. by the various printing methods, for example on the surface / or back surface of a nonwoven fabric.

Moreover, you may give a filter canceling property and / or antibacterial property. As a substance which gives repellency, powdered activated carbon etc. are mentioned, for example. Furthermore, as a substance which provides antibacterial property, titanium oxide etc. are mentioned, for example. These may be contained in the fiber of a filter beforehand, and after manufacture of a filter, you may adhere to a filter surface by application | coating method etc., or may impregnate each fiber in a filter surface.

The length and width of the nonwoven fabric are not limited. The point should just be a rectangular shape in plan view which can cover the whole area of the back part of a wing guard from the outside. However, the size of a typical household fan is about 40 cm in the average diameter of the wing guard, the average of the diameter of the motor portion is about 12 cm. Correspondingly, preferred dimensions of the nonwoven fabric are 110 to 130 cm in length (long side) and 20 to 24 cm in width (short side). In addition, the diameter of the rotating blades for home use is 35 cm, and the diameter of the rotating blades for home use is 30 cm.

The position of the wing guard covered by a nonwoven fabric is not limited to a back part. Both the rear part and the front part of the wing guard may be used.

The material of the elastic band is not limited. For example, a metal band having elasticity, such as a rubber band, a stretchable synthetic resin band, or a coil spring, may be used. This elastic band may be made of an elastic body only in part of its longitudinal direction. In general, however, the entire length of the band is made of an elastic body.

The type of fitting member is not limited. For example, a hook, a hook, a surface fastener, or an adhesive tape may be sufficient.

The member into which the fitting member is fitted may be, for example, a nonwoven fabric or a part of a fan such as a wire rod of a wing guard.

The diameter of the band guide is not limited. In other words, the elastic band may be inserted. The band guide portion may be provided with one long one along the long side of the nonwoven fabric, or may be divided into a plurality of band guides.

The length of both elastic bands must be shorter than the long side of the nonwoven fabric. By shortening, a wrinkle is formed in the whole nonwoven fabric, especially the both ends of the long side of a nonwoven fabric, respectively. In addition, the length of the elastic band by the side of the motor part of a fan, and the length of the elastic band by the front part side of the wing guard arrange | positioned on the contrary are not limited. In general, however, the elastic band on the motor side is 60 to 70 cm, and the elastic band on the opposite side is 80 to 90 cm. That is, the difference in length is 10 to 30 cm.

The invention according to claim 2 is a fan filter according to claim 1, wherein the fitting member is a hook which can be freely hooked or removed from the wire rod.

The shape of the hook is not limited. That is, it is good if it is a shape which can be hung on a wire rod or taken out.

The invention according to claim 3 is the fan filter according to claim 1 or 2, wherein the elastic band is a rubber band.

The kind of rubber band is not limited. Plain rubber may be sufficient and round rubber may be sufficient. In the case of flat rubber, its expansion ratio is usually 2.5 times.

The invention as set forth in claim 4 is a wing guard which covers the rotary blades of the fan from the outside by cutting the end of the band-shaped nonwoven fabric derived from the nonwoven fabric roll over the entire length of the width of the band-shaped nonwoven fabric from the direction orthogonal to its derivation direction. A step of forming a substantially rectangular nonwoven fabric that can cover the back portion, a step of forming a tubular band guide portion in which an elastic band is inserted over almost the entire length at both edges of the long side of the substantially rectangular nonwoven fabric, and one of the above Injecting elastic bands shorter than the long side of the nonwoven fabric into the band guide portion, inserting the long side of the nonwoven fabric and the other elastic band shorter than the elastic band on the other band guide portion, and each elasticity At both ends of the band, a covering state of the back portion of the wing guard by the nonwoven fabric is applied. An underground filter is a manufacturing method of the fan filter provided with the process of installing each fitting member.

According to the invention of Claims 1 and 4, since the nonwoven fabric is made into a rectangular shape, when the nonwoven fabric is cut, for example, a nonwoven fabric roll such as cloth is prepared, and the band-shaped nonwoven fabric derived from the roll is cut by a predetermined length, Rectangular nonwovens can be produced in a simple and high yield (claim 4). Thereby, cost reduction of the filter for electric fans can be aimed at.

When using a filter, pull out and extend both ends of the short length elastic band and the long elastic band respectively inserted into the corresponding band guides, and then insert each fitting member into the nonwoven fabric or a part of the fan, respectively, and outward the wing guard by the nonwoven fabric. Cover from.

At this time, the pair of elastic bands are different in length from the inner circumferential portion, which is the small diameter of the wing guard, and the outer circumferential portion of the large diameter. In addition, since these elastic bands are freely moved in the longitudinal direction within the corresponding band guides, the nonwoven fabric (filter material) at the time of filter mounting, like a filter for a fan in which a conventional nonwoven fabric and an elastic band are integrated. The stretch of the elastic band is not limited to the length of. Therefore, regardless of the size (diameter, etc.) of the wing guard, the whole of the wing guard can be coated well.

In addition, when a nonwoven fabric integrated with such an elastic band is used, the nonwoven fabric is shortened only to the length of the portion where the nonwoven fabric is fixed in the entire length of the elastic band. Therefore, when the small wing guard was covered with a large fan filter for a large fan, the shape of the nonwoven fabric was easily crushed and loosened. Therefore, a gap was easily formed between the nonwoven fabric and the wing guard, especially on the motor part side having a small diameter. Therefore, fine dusts may be sucked into the wing guard from this gap. However, in the present invention, the elastic band is stretched and contracted separately from the nonwoven fabric by the band guide portion, and the nonwoven fabric can be adhered to the motor portion, thereby eliminating this problem. As a result, the sealing property of the back part of the wing guard by a fan filter becomes high, and the dust collection effect of a fan filter can be improved.

Further, the shape of the nonwoven fabric is a square shape in which a pair of long sides are the same length, and both elastic bands are moved in the longitudinal direction to each corresponding band guide of the nonwoven fabric (or the nonwoven fabric slides the outer circumferential surface of the elastic band). When the band is inserted, a lot of wrinkles are formed in the entire nonwoven fabric covering the back portion of the wing guard, particularly at one end of the long side of the nonwoven fabric covering the inner circumferential portion, which is a small diameter of the wing guard, regardless of the extent of elastic band extension. Is formed. Therefore, the pleats increase the sealing property of the filter and at the same time, the collecting area also increases. As a result, the dust collection effect of the connection part of a wing guard and a motor part can be heightened further.

Particularly, according to the invention of claim 2, since the fitting member is a hook that can be freely hooked or pulled out of the wire rod, in use, the short length elastic band and the long elastic band inserted into the corresponding band guide portion are respectively increased. , Fit each fitting member to the wire of fan. As a result, the number of times of repeated use of the fitting member can be increased, and the nonwoven fabric can be firmly fixed to the wing guard by using the wire rod of the wing guard.

However, the hook does not necessarily need to be hung on the wire rod. For example, you may hang the hook provided in one end of one elastic band, and the hook provided in the end of the other end.

[Embodiment of the Invention]

Hereinafter, one embodiment of the present invention will be described.

1 is a perspective view of a state of use of the fan filter according to an embodiment of the present invention. 2 is a plan view of a fan filter according to an embodiment of the present invention. 3 is a perspective view showing a cutting process of a nonwoven fabric in a method of manufacturing a fan filter according to an embodiment of the present invention.

1 and 2, reference numeral 10 denotes a fan filter according to an embodiment of the present invention. The fan filter 10 surrounds the rotary vanes 13 fixed to the output shaft of the motor unit 12 of the fan 11 from the outside and has a plurality of wire rods 14 of the wing guard 15. By the nonwoven fabric 16 which can cover the back part 15A, and a pair of flat rubber bands (elastic bands) 17, 18 and the nonwoven fabric 16 which are elastic materials attached to both peripheral parts of this nonwoven fabric 16, respectively. Four hooks (fitting members) 19 for maintaining the covering state of the back portion 15A are provided.

The nonwoven fabric 16 is rectangular in plan view, and as shown in FIG. 3, it is easy by sequentially cutting the band-shaped nonwoven fabric 16 having a width (short side) of about 24 cm derived from the nonwoven fabric roll R every 130 cm in length (long side). You can get it. Furthermore, no unnecessary waste occurs and the nonwoven fabric 16 can be manufactured with high yield. Thereby, the cost of the fan filter 10 can be reduced. When cut to this size, the obtained nonwoven fabric 16 can cover almost the entire area of the back portion 15A of the wing guard 15 having a diameter of 35 cm from the outside.

The nonwoven fabric 16 is obtained by adhering polyester resin fibers having a fiber diameter of about 10 denier with a predetermined binder. The mesh degree is 30 g / m 2, the apparent thickness is 1-3 mm, and the filter pressure loss is 0.20 mmH ₂ O.

Both edges of the long side of the nonwoven fabric 16 are each folded about 10 mm inwardly, and the folded portions are heat-sealed in tubular form, and each flat rubber band having a width of about 3.5 mm over the entire length of these long sides ( A pair of band guides 20 and 21 for injecting 17 and 18, respectively, is formed.

The length of the flat rubber band 17 on the short side is 70 cm. The length of the flat rubber band 18 of a long side is 90 cm. Accordingly, the lengths of the flat rubber bands 17 and 18 are shorter than 130 cm of the long sides of the nonwoven fabric 16, respectively. Accordingly, when the flat rubber bands 17 and 18 are inserted into the corresponding band guides 20 and 21, the entire nonwoven fabric 16, in particular, on both edge portions of the long side of the nonwoven fabric 16, respectively. Many wrinkles are formed (FIG. 1). Among these, the flat rubber band 17 is only 20 cm shorter than the flat rubber band 18. Therefore, more wrinkles arise around the band guide part 20 side of the nonwoven fabric 16.

The hooks 19 have an S-shape in plan view. These hooks 19 are firmly fixed to both ends of the flat rubber bands 17 and 18 by a caulking method using a short metal pipe.

Next, a method of using the fan filter 10 according to the embodiment will be described.

As shown in FIGS. 1-3, when using this fan filter 10, it is wrinkled in the center part of the short flat rubber band 17 in the edge part of the band guide part 20 side of the nonwoven fabric 16 beforehand. Tie the band guide portion 20 to the apparent length of about 40cm. As a result, both ends of the flat rubber band 17 protrude outwards by about 15 cm from both ends of the shortened band guide 20. In this state, the back portion 15A of the wing guard 15 is covered with the nonwoven fabric 16 from the outside. At this time, the edge portion of the band guide portion 20 side of the nonwoven fabric 16 is directed toward the motor portion 12 side having a small diameter, while the edge portion of the band guide portion 21 side of the nonwoven fabric 16 is wing guard ( Toward the connecting side of the large diameter front portion 15B. At the time of coating of the wing guard 15, if both ends of the overlapping short side of the nonwoven fabric 16 are positioned to face the main side of the wing guard 15, subsequent operations can be performed in a relatively convenient order. .

Next, after crossing both ends of the short flat rubber band 17, it winds around the outer peripheral surface of the original part of the motor part 12, and a flat rubber band at the position on the opposite side to the motor part 12 from an intersection point. Hook (19), (19) of both ends of (17) are fastened. Thereby, the edge part by the side of the band guide part 20 of the nonwoven fabric 16 is firmly fixed to the original part of the motor part 12. As shown in FIG. At this time, a large number of wrinkles are formed in the entire band of the nonwoven fabric 16, particularly the portion of the band guide portion 20 of the nonwoven fabric 16 covering the inner circumferential portion of the back portion 15A, regardless of the degree of extension of the flat rubber band 17. do. As a result, the airtightness of the filter 10 for electric fans is further increased by these wrinkles, and the area for collecting fine particles and dust is also increased. As a result, the dust collection effect of the connection part of the wing guard 15 and the motor part 12 can be heightened further.

On the other hand, by pulling the both ends of the long flat rubber band 18 inserted into the band guide portion 21 to intersect both ends of the flat rubber band 18, both hooks 19, 19 in front as it is In the part on the back part 15A side of the part 15B, it hangs on the predetermined wire 14. As shown in FIG. Then, the two hooks 19 and 19 are slid along the wire 14 to the end of the rear portion 15A side of the front portion 15B, and then a portion of the outer edge of the nonwoven fabric 16 is picked up, This is covered on both ends 19 of the flat rubber band (18). Thereby, the external appearance of the filter 10 for electric fans becomes favorable.

Then, from the rear of the fan 11, the mounting state of the fan filter 10, that is, the appearance of wrinkles and pulls of the entire nonwoven fabric 16 is checked. That is, it adjusts so that wrinkles etc. may appear in a uniform radial state across the nonwoven fabric 16 centering on the motor part 12. As shown in FIG.

Then, when the output shaft of the motor part 12 is rotated and the rotary vane 13 is rotated, indoor air is sucked into the inner space of the wing guard 15 from the rear part 15A of the wing guard 15. And it blows in the front of the fan 11 from the front part 15B of the wing guard 15. As shown in FIG. At this time, fine particles and dust suspended in the indoor air are filtered at a high dust collection rate by the nonwoven fabric 16 almost completely covering the entire back portion 15A.

The length of the pair of long and short flat rubber bands 17 and 18 is determined beforehand by the inner circumferential portion, which is the small diameter of the wing guard 15, or the outer circumferential portion, which is the large diameter. In addition, the conventional nonwoven fabric and the elastic band are integrated because both flat rubber bands 17 and 18 are inserted as moving materials in the longitudinal direction in the corresponding band guides 20 and 21 of the nonwoven fabric 16. As described above, the extension of the flat rubber bands 17 and 18 is not limited to the length of the nonwoven fabric 16 when the filter is mounted. Therefore, regardless of the size (diameter, etc.) of the wing guard 15, the whole of the wing guard 15 can be coat | covered favorably.

When the nonwoven fabric integrated with such an elastic band is used, the nonwoven fabric is shortened only to the length of the portion where the nonwoven fabric is fixed in the entire length of the elastic band. Therefore, when the small wing guard is coated with a filter for a large fan, the shape of the nonwoven fabric is crushed and easily relaxed. As a result, a gap is easily formed between the nonwoven fabric and the wing guard, particularly on the motor part side having a small diameter. Therefore, there was a possibility that fine dusts were sucked into the wing guard from this gap.

However, in one embodiment, the nonwoven fabric 16 may be stretched because the elastic rubber bands 17 and 18 can be stretched separately from the nonwoven fabric 16 due to the presence of the band guides 20 and 21. It is possible to be in close contact with the portion 12. Therefore, the above-mentioned disadvantages of the prior art can be solved. As a result, the sealing property of the back part 15A of the wing guard 15 by the fan filter 10 becomes high, and the dust collection effect of the fan filter 10 can be improved.

Moreover, according to the conventional fan filter, if a large wing guard was forcibly covered by the fan filter for a small fan, since a nonwoven fabric and an elastic band were integrated in this way, it was easy to damage a nonwoven fabric. However, in this embodiment, such concerns are also eliminated.

In addition, the shape of the nonwoven fabric 16 is a square shape in which the length of a pair of long sides is the same, and further, both the flat rubber bands 17 and 18 correspond to respective band guide portions of the nonwoven fabric 16 ( 20) and 21 are freely moved in the longitudinal direction and inserted. Therefore, even when the fan used is fitted with a large fan (35 cm in diameter), even if it is small (30 cm in diameter), Regardless of the extent of stretching of the rubber bands 17 and 18, many wrinkles are formed in the entirety of the nonwoven fabric 16, particularly in the portion of the nonwoven fabric 16 covering the inner circumference of the wing guard 15. Therefore, including the handle which protrudes more than the upper part of this back part 15A, the airtightness of the filter 10 for electric fans becomes high by wrinkles, and the collection area of this wrinkles formation part is also expanded. As a result, the dust collection effect of the connection part of the wing guard 15 and the motor part 12 can be heightened further.

In addition, in one embodiment, since the hook 19, which is freely hooked to the wire rod 14, is adopted as the fitting member, it is possible to increase the number of times of repeated use of the fitting member, for example, in comparison with a conventional surface fastener. There is a number. In addition, the nonwoven fabric 16 can be firmly fixed to the wing guard 15 using this wire rod 14.

According to the inventions of the first and fourth aspects of the present invention, since the nonwoven fabric is formed into a square shape in plan view, for example, the nonwoven fabric can be easily produced by sequentially cutting the band-shaped nonwoven fabric derived from the nonwoven fabric roll one by one for a predetermined length. (Claim 4). Moreover, the nonwoven fabric can be manufactured in high yield without generating unnecessary waste. As a result, the cost of the fan filter can be reduced.

In addition, the length of the pair of elastic bands was changed according to the inner circumference portion or the large diameter outer circumference portion of the wing guard, and each elastic band was induced to move freely in its length direction in the corresponding band guide portion. Irrespective of the size of the wing guard to be mounted, the entire wing guard can be well covered. As a result, the sealing property of the back part of the wing guard by a fan filter becomes high, and the dust collection effect of this fan filter can be improved.

In addition, since the shape of the nonwoven fabric was made into a rectangular shape and both elastic bands were inserted into the band guide portion, the wrinkles formed throughout the nonwoven fabric, especially the inner circumference of the wing guard, were covered regardless of the extent of elastic band extension. The pleats formed in the portion of the nonwoven fabric further increase the sealability of the filter. In addition, the collection area in the wrinkles is also increased. As a result, the dust collection effect of the connection part of a wing guard and a motor part can be heightened further.

In particular, according to the invention of claim 2, since the fitting member is a hook that can be freely hooked to the wire rod, the number of times of repeated use of the fitting member can be increased. Can be fixed

Claims (4)

A substantially rectangular nonwoven fabric capable of covering the back side of the wing guard having several wire rods while covering the rotary blades fixed to the output shaft of the fan motor unit from the outside, and a pair of elastic materials mounted on both edges of the nonwoven fabric. In the fan filter having an elastic band and a fitting member for maintaining the covering state of the back portion of the wing guard by the nonwoven fabric, On both edges of the long side of this nonwoven fabric, a pair of tubular band guides for injecting each elastic band over almost the entire length are disposed, The length of both elastic bands is made shorter than the long side of the nonwoven fabric, and the length of the elastic bands inserted into the band guide portion on the motor side is made shorter than the elastic band on the front side of the wing guard. A fan filter, in which the fitting member is disposed at both ends of each elastic band. The fan filter according to claim 1, wherein the fitting member is a hook which can freely hang or pull out the wire rod. The fan filter according to claim 1 or 2, wherein the elastic band is a rubber band. An almost square shape capable of covering the back portion of the wing guard covering the rotary blades of the fan from the outside by cutting the end of the band-shaped nonwoven fabric derived from the nonwoven roll over the entire length of the width of the band-shaped nonwoven fabric from the direction orthogonal to its derivation direction. Process of forming a nonwoven fabric, A step of forming a tubular band guide portion in which an elastic band is inserted over almost the entire length at both edges of the long side of the substantially rectangular nonwoven fabric, and Injecting an elastic band shorter than the long side of the nonwoven fabric into one electric band guide portion; Injecting a long side of the nonwoven fabric and another elastic band shorter than the one elastic band to the other electric band guide portion; A step of providing fitting members for maintaining the state of covering of the back portion of the wing guard by the nonwoven fabric at both ends of each elastic band, respectively. Method for producing a fan filter consisting of.