JP2004305853A - Nonwoven fabric for canister filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide nonwoven fabric which is used as a canister filter for preventing fuel vapor leaking through an intake system from diffusing into ambient air, which hardly passes fine particles of granular activated carbon and which is hardly clogged with dust, or the like. <P>SOLUTION: This nonwoven fabric is obtained by bonding a fiber layer 1 of a polyester long fiber formed by spun-bonding and a fiber layer 2 of a polyester short fiber by using a fusing fiber 3 so that this nonwoven fabric has ≤150 μm maximum pore size and ≥20.0 g/m<SP>2</SP>peeling strength. The fiber layer of the polyester short fiber is formed by mixing a fine-denier fiber with a coarse-denier fiber by 30/70 to 50/50 mass% mixing ratio to obtain a short fiber web, entangling the obtained web and bonding the entangled web by using a resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００３５】
上記表１よりみて本発明の実施例に係る不織布は特に塵埃保持量と共に加工性，活性炭透過性において比較例の不織布に平均して一段と優れていることが分かる。
【００３６】
【発明の効果】
以上のように本発明は長繊維繊維層と短繊維繊維層を熱融着性繊維で互いに接着したもので、少なくとも１５０μｍ以下のポアサイズで２０．０Ｎ／ｃｍ^２以上の剥離強力を有するように構成した不織布であり、長繊維層で細かい塵を取ると同時に活性炭の抜けを防いで活性炭の微粒子が抜けにくく、かつ、ダスト等による目詰まりを起こしにくい特性を具備して、キャニスターフィルタ用として極めて優れた実用的効果を奏する。
特に短繊維層と長繊維層の接着はニードル加工を介して接着すると最終レジンボンドでもスパンボンドにニードルであけられた孔は小さくすることが難しくキャニスターフィルタ用としての機能を阻害するが、熱融着性繊維により接着したことによりポアサイズのコントロールを良好にし、活性炭微粒子を外部に出さない効用を発揮すると共に、短繊維層の形成にあたってニードルパンチと樹脂接着を併用することにより、毛抜け，繊維間ズレをなくし、寸法安定性を良好ならしめる効果を有する。
【図面の簡単な説明】
【図１】本発明に係る不織布の断面概要図である。
【符号の説明】
１ 長繊維層
２ 短繊維層
３ 熱融着性繊維[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an adsorption filter for an internal combustion engine, and more particularly to a nonwoven fabric suitable for use in a so-called canister filter, which is a fuel vapor collector for preventing fuel vapor leaking through an intake system from diffusing into the outside air.
[0002]
[Prior art]
Gasoline vapor evaporated from a gasoline tank of an automobile or a gas station where the engine is stopped has conventionally been released into the atmosphere without being recovered.
In recent years, a collector filled with an adsorbent (canister) has been installed in the middle of the discharge pipe to prevent the fuel vapor leaking through the intake system from flowing out to the atmosphere due to the request for environmental purification, and evaporating. An air cleaner is provided with an adsorbent that adsorbs gasoline that has been adsorbed and then desorbs and supplies air to the engine in the opposite direction during the next run.
[0003]
Then, as a method of arranging an adsorbent for preventing the fuel vapor leaking through the intake system from flowing out to the atmosphere, a sheet in which the adsorbent is sandwiched between two layers of filter paper or a nonwoven fabric is made, and an air cleaner is formed. There is proposed a configuration for fixing the inside. (For example, see Patent Document 1)
However, since the element and the element provided with the adsorbent are provided in parallel, there is a risk that fuel vapor may leak to the atmosphere through the element.
Further, the nonwoven fabric of the element is easily clogged with dust, and as a result, there is a problem that the airflow resistance of the element provided with the adsorbent is greatly increased, and the adsorbing power of the fuel vapor is greatly reduced.
[0004]
Therefore, on the internal combustion engine side of the filter element, a sheet-shaped adsorption filter in which granular activated carbon is sandwiched between a heat-resistant net and a nonwoven fabric is arranged, and when the engine stops, gasoline vapor attached to the engine enters the air cleaner. Since the gasoline vapor is adsorbed by the granular activated carbon, an air cleaner for an internal combustion engine has been proposed which does not flow out to the atmosphere and has a heat-resistant net so as to withstand a backfire. (For example, see Patent Document 2)
[0005]
[Patent Document 1] Japanese Utility Model Application Laid-Open No. Sho 60-14269 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-276486
[Problems to be solved by the invention]
However, even if the above-mentioned one also has the effect of heat resistance, the non-woven fabric filter is clogged by activated carbon particles and dust particles, and as a result, the airflow resistance is greatly increased and the fuel vapor adsorption capacity is greatly increased. There is a problem that it decreases.
[0007]
The present invention has been made in view of the above situation, and in order to deal with this, in a non-woven fabric filter of a so-called canister, a fuel vapor collector for preventing the diffusion of fuel vapor leaking through the intake system to the outside air, the granular activated carbon is used. An object of the present invention is to provide a nonwoven fabric filter in which fine particles are hardly removed and clogging with dust or the like is less likely to occur.
[0008]
[Means for Solving the Problems]
That is, the present invention, which meets the above object, is a non-woven fabric comprising a polyester fiber layer and a polyester staple fiber layer obtained by a spunbond method and bonded by a heat-fusible fiber. A nonwoven fabric for a canister filter, wherein the nonwoven fabric has a maximum pore size of 150 µm or less and a peel strength of 20.0 N / cm ² or more.
[0009]
Claim 2 is a nonwoven fabric for a canister filter, wherein the nonwoven fabric has a maximum pore size of 150 μm or less, has a collection efficiency of at least 95% and a pressure loss of 150 Pa or less, and has a peel strength of 20.0 N / cm ² or more.
This increases the recovery of the fuel vapor and makes it more suitable for release.
[0010]
Claims 3 to 7 are preferred embodiments of the fineness of the polyester fibers of the long fibers and short fibers, the ratio of short and thick fibers mixed, the heat-fusible fiber, and the adhesive resin used in the construction of the nonwoven fabric. it fineness of polyester filament obtained by the spunbond method in the range of 6.0 dtex to 1.0 dtex, and the fiber layer basis weight is preferably in the range from 20 g / ^{m 2} of 100 g / ^{m 2,} According to a fourth aspect of the present invention, the fiber layer of the polyester short fiber has a fine fineness and a fine fineness, and the fine fineness is in a range from 1.0 decitex to 5.0 decitex, and the fine fineness is in a range from 5.0 decitex to 10.0 decitex. There, and in 50/50 wt% mixed fiber ratio from 30/70 wt% fine / thick fibers, and it basis weight in the range of 150 g / ^{m 2} of 600 g / ^{m 2,} claim 5 polyester staple Fiber The fiber layer of the fiber is obtained by entanglement of the mixed short fiber web and further by resin bonding. Claim 6 is that the adhesive resin forming the fiber layer of the polyester short fiber is an acrylic resin, The heat-fusible fiber is made of a low-melting polyester resin, has a melting point of 120 ° C. to 200 ° C., and is in the form of a hot melt sheet. When the basis weight is in the range of 10 g / m ² to 100 g / m ² , a preferable nonwoven fabric for a canister filter of the present invention can be obtained.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, specific embodiments of the nonwoven fabric of the present invention will be described in detail.
[0012]
FIG. 1 is a schematic view of a cross-sectional structure of the nonwoven fabric of the present invention, in which a fiber layer 1 made of polyester long fibers and a fiber layer 2 made of polyester short fibers obtained by a spunbond method are bonded by heat-fusible fibers 3. The nonwoven fabric of the present invention is constituted.
Then, the present invention considers various characteristics for making this nonwoven fabric effective as a nonwoven fabric for a canister filter.First, the nonwoven fabric filters external air dust, and also collects and discharges fuel vapor, that is, a fuel From the viewpoint that it is necessary to have a role of steam permeability, initial pressure, and not to emit activated carbon fine particles to the outside, that is, to have a role of pore size (viscosity distribution of activated carbon) and gasoline oil resistance, pore size and gasoline resistance Each characteristic such as filtration, filtration performance, gasoline permeability, dimensional stability, and peel strength was examined to prevent activated carbon from leaking. The pore size was 150 μm or less (amount of 5.0 μm passage), and from the viewpoint of filtration performance. collecting efficiency of 95% or more, pressure loss 150Pa or less, even more workability surface peel strength 20.0N / cm ² or more, the makes it even better gasoline resistance The strength of 20 N / 5 cm or higher, dimensional change of 1.0% or less, and dimensional stability have found that the individual properties of 1.3% or less is preferable.
Among these, the most basic minimum requirements for the nonwoven fabric of the present invention are that the maximum pore size is 150 μm or less and the peel strength is 20.0 N / cm ² or more.
[0013]
If the pore size of the nonwoven fabric exceeds 150 μm, there is a problem that fine particles in the activated carbon pass through and damage the engine.
Further, if the peel strength of the nonwoven fabric is less than 20.0 N / cm ² , the long fiber fiber layer and the short fiber fiber layer are easily separated at the time of molding to deteriorate the processability, and the layers are separated during use, so that the filter is removed. This is not preferred because it hinders the performance of
[0014]
The structure of the nonwoven fabric of the present invention is formed based on each of the above-described characteristics to realize the same. The fineness and basis weight of the long fibers constituting the long fiber layer and the fineness and basis weight of the short fibers constituting the short fiber layer are provided. The means for integration, the means for joining the two fiber layers, and the like are specified as follows.
[0015]
First, among the long fiber layer and the short fiber layer to be fused, the long fiber constituting the fiber layer of the polyester long fiber obtained by the spun bond method has a fineness in a range of 1.0 dtex to 6.0 dtex. it is preferable, also, the basis weight of the fibrous layer, it is effective is ^{20g / m 2 ~100g / m 2} .
When the fineness of the long fiber is less than 1 dtex, it is very effective to reduce the pore size of the nonwoven fabric, but it is not preferable because the initial pressure is rather increased.
On the other hand, if it exceeds 6.0 decitex, on the contrary, the pore size of the nonwoven fabric becomes too large, which is not preferable.
If the basis weight of the long fiber layer is less than 20 g / m ² , the nonwoven fabric becomes thin and the initial pressure is good, but it is difficult to reduce the pore size.
On the other hand, if it exceeds 100 g / m ² , the pore size of the nonwoven fabric can be reduced, but the initial pressure is undesirably high.
[0016]
Next, it is effective that the fiber layer made of polyester short fibers is formed by mixing fine-fiber fibers and thick-fiber fibers, and the fineness is preferably in the range of 1.0 dtex to 5.0 dtex. The fineness is preferably in the range of 5.0 dtex to 10.0 dtex.
If the fiber fineness of the thick fineness is less than 5.0 decitex and the fiber fineness of the fine fineness is less than 1.0 decitex, the role of the coarse layer of the filter medium is not sufficiently fulfilled, and the initial pressure is increased.
On the other hand, when the fineness exceeds 10.0 decitex and the fineness exceeds 5.0 decitex, the medium does not sufficiently serve as the middle layer of the filter medium, and the initial pressure is increased.
[0017]
When mixing the above fine and fine fibers, it is preferable to use a fine / thick mixed fiber in which the mass% is in the range of 30/70 to 50/50, and the mixing ratio of the fine fineness is less than 50% by mass. If it is present, the role of the coarse layer of the filter medium becomes insufficient. On the other hand, if the fineness is more than 70% by mass, the role of the middle layer of the filter medium, which is the role of fineness, becomes insufficient.
The basis weight of the short fiber layer made of the mixed fiber having the fineness / thickness is 150 to 600 g / m ² , and more preferably 200 to 400 g / m ² .
If it is less than 150 g / m ² , the filtration capacity will be small and the filtration performance will decrease, and if it exceeds 600 g / m ² , the filtration performance will be excessive.
In the formation of the fiber layer by mixing the fine / thick fibers, the webs of the mixed fibers are entangled and integrated with each other by a known needle processing. Since it is not sufficient, it is important to further fix and adhere with a resin.
As the resin, known adhesive resins can be used, but acrylic resin is most preferable, and the amount of adhesion is preferably 5 to 20% by weight with respect to the short fiber layer. Is not sufficient, and if it exceeds 20% by weight, pores between fibers are crushed, and the filtration performance is undesirably reduced.
The long-fiber fiber layer 1 and the short-fiber fiber layer 2 formed as described above are bonded to each other by the heat-fusible fibers 3 to form a nonwoven fabric having the form shown in FIG.
The interlayer bonding between the long fiber layer 1 and the short fiber layer 2 is difficult to control the pore size in the filtration performance only by needle processing, and a large pore diameter of 200 μm or more is not preferable. Use is important.
[0018]
It is also possible to use ordinary resin bonding or needle processing together with the resin bonding, but this is not preferred because it results in a decrease in peel strength and filtration performance.
The heat-fusible fiber to be used is preferably a low-melting polyester resin having a melting point of 120 to 200 ° C. If the temperature is lower than 120 ° C, there is a problem in heat resistance. Absent.
[0019]
The heat-fusible fibers are usually arranged between the layers as a thin layered web-like sheet, and the layers are fused by heating.
The amount of the heat fusible fiber to be applied is preferably in the range of 10 to 100 g / m ² in terms of basis weight. If it is less than 10 g / m ² , the interlayer adhesion between the two fiber layers will be insufficient, while if it exceeds 100 g / m ² , the amount of adhesion will be excessive and the filtration performance will be undesirably reduced.
[0020]
Thus, the nonwoven fabric of the present invention by bonding the above two layers controls the maximum pore size in the long fiber layer, removes coarse dust in the short fiber layer, and removes fine dust in the spun bond layer while preventing the activated carbon from coming off. The purpose of the canister filter can be achieved.
[0021]
Hereinafter, examples of the present invention will be specifically described in comparison with comparative examples.
[0022]
【Example】
Example 1
After uniformly mixing polyester fibers having a fiber length of 51 mm with a fineness of 3.3 dtex and a fiber length of 51 mm with a fineness of 6.6 decitex at a mixing ratio of 30% by mass and 70% by mass, carding is performed and the basis weight is reduced. A short fiber layer of 350 g / m ² was obtained.
Subsequently, the staple fiber layer was entangled with a needle by a needle punch machine at a needle depth of 10.0 mm and a number of shots of 20 / cm ² .
Further, the entangled short fiber layer is successively immersed in a binder containing acrylate ester as a main component, and the squeezing ratio is set to 100% by mass to give a binder adhesion amount of 12.5% by mass to the short fiber layer. did. The obtained short fiber layer had a basis weight of about 400 g / m ² .
A polyester long fiber layer having a basis weight of 50 g / m ² at an average fineness of 1.6 dtex obtained by a spun bond method and a short melt fiber sheet of low melting polyester long fiber (melting point 140 ° C.) 20 g / m ^{2 were obtained.} At a roller temperature of 160 ° C., a gap between rollers of 6 mm, and a processing speed of 5 m / min to obtain a nonwoven fabric for a canister filter of the present invention having excellent workability and filterability.
[0023]
Example 2
Using the same short fiber fiber layer (with the entanglement treatment binder applied) as in Example 1, the basis weight of the polyester long fiber layer having an average fineness of 1.6 dtex obtained by the spun bond method was set to 20 g / m ² .
Adhesion between the short fiber fiber layer and the long fiber fiber layer by the spun bond method was performed in exactly the same manner as in Example 1 to obtain a nonwoven fabric for a canister filter of the present invention.
[0024]
Example 3
After uniformly mixing polyester fibers having a fiber length of 51 mm with a fineness of 3.3 dtex and a fiber length of 51 mm with a fineness of 6.6 decitex at a mixing ratio of 30% by mass and 70% by mass, carding is performed and the basis weight is reduced. A short fiber layer of 350 g / m ² was obtained.
Subsequently, the staple fiber layer was entangled with fibers by a needle punching machine with a needle depth of 10.0 mm and a needle number of 20 pieces / cm ² .
Further, the entangled short fiber layer is successively immersed in a binder mainly composed of an acrylate ester, and the squeezing ratio is set to 100% by mass to give a binder adhesion amount of 18.6% by mass to the short fiber layer. did. The obtained short fiber layer had a basis weight of about 430 g / m ² .
A polyester long fiber layer having a basis weight of 50 g / m ² at an average fineness of 1.6 dtex obtained by a spun bond method and a short melt fiber sheet of low melting polyester long fiber (melting point 140 ° C.) 20 g / m ^{2 were obtained.} At a roller temperature of 160 ° C., a gap between rollers of 6 mm, and a processing speed of 5 m / min to obtain a nonwoven fabric for a canister filter of the present invention having excellent workability and filterability.
[0025]
Example 4
Using the same short fiber fiber layer as in Example 1 (with the entanglement treatment binder applied), using a basis weight of 50 g / m ² of a polyester long fiber layer having an average fineness of 1.6 dtex obtained by a spun bond method, A roller similar to that of Example 1 except that the polyester long fiber layer used for bonding the short fiber fiber layer and the fiber layer of the spun bond method had a hot melt sheet basis weight of low melting polyester long fiber (melting point 140 ° C.) of 80 g / m ^2. A nonwoven fabric for a canister filter having excellent workability and filterability of the present invention was obtained by heat fusion at a temperature of 160 ° C. with a gap between rollers of 6 mm and a processing speed of 5 m / min.
[0026]
Comparative Example 1
After uniformly mixing polyester fibers having a fiber length of 51 mm with a fineness of 3.3 decitex (dtex) and a fiber length of 51 mm with a fineness of 6.6 decitex at a mixing ratio of 30% by mass and 70% by mass, carding is performed. A short fiber layer having a basis weight of about 350 g / m ² was obtained.
Subsequently, this short fiber layer was laminated with a polyester long fiber layer having a basis weight of 50 g / m ² at an average fineness of 1.6 dtex obtained by a spun bond method, and a needle punch machine was used to obtain a needle depth of 10.0 mm and the number of punching was 20. The fibers were entangled with each other by needle processing at a density of / cm ² .
Subsequently, the laminated fiber layer of the long fiber layer and the short fiber fiber layer that has been entangled is immersed in a binder mainly composed of acrylate, the drawing ratio is set to 100% by mass, and the amount of the binder adhering to the laminated fiber layer is adjusted. 12.5% by mass. The obtained laminated fiber layer gave a nonwoven fabric for a comparative canister filter having a basis weight of about 457 g / m ² .
[0027]
Comparative Example 2
Using the same short fiber fiber layer (with the entanglement treatment binder applied) as in Example 1, the basis weight of the polyester long fiber layer having an average fineness of 1.6 dtex obtained by the spun bond method was 110 g / m ² . Adhesion between the short fiber layer and the fiber layer by the spun bond method was performed in exactly the same manner as in Example 1 to obtain a nonwoven fabric for a comparative canister filter.
[0028]
Thus, each of the nonwoven fabrics obtained in Examples 1 to 4 and Comparative Examples 1 and 2 was evaluated for filtration performance, workability, and activated carbon permeability in order to compare the performance. The results were as shown in Table 1 below.
Each measurement of the basis weight, thickness, peel strength (vertical peel strength) and pore size in the table, and evaluation of filtration performance, workability and activated carbon permeability were performed according to the following methods.
[0029]
(1) Weight per unit area: determined according to the method described in 5.2 of JIS L1906.
(2) Thickness: Measured under a load of 2 Kpa according to the method described in 5.1 of JIS L1906.
(3) Peeling strength: After cutting the test piece into a 5 cm square, a double-sided adhesive tape (NO523, manufactured by Nitto Denko) was applied to both sides, attached to an attaching jig, and vertically moved at 200 mm / min by a Tensilon tensile tester. And the maximum point is measured and expressed as the average value. (Up to the integer position) n = 3
(4) Measurement of pore size: It was measured based on the bubble point method of Coulter porometer ASTMF-361-80 manufactured by Coulter Corporation.
(5) Evaluation of filtration performance: Initial pressure loss (ΔP) and dust retention (DHC) were evaluated based on JIS D1612 automotive air cleaner test method.
[0030]
(Experiment conditions)
a) JIS Class 8 dust (JIS Z8901) dust concentration is 6 g / m ³
b) The element of the air cleaner used for the test is a disk filter medium having an effective area of 1000 cm ² c) The test wind speed: 25 cm / sec
d) Final pressure loss: 98 Pa [10 mmAg]
(Evaluation)
ΔP: Initial pressure difference before and after sample setting DHC; Dust holding amount at increasing resistance of 300 mmAq
(6) Workability evaluation test Hydraulic clicker (punching machine) HMO-10 type (Hori Iron Works)
Press pressure 3.5 ton (350mm × 500mm)
550mm x 1000mm x 20mm polyethylene Thomson blade (50mm x 100mm x 5)
(Evaluation)
Place the sample on a polyethylene plate, place a Thomson blade on it, and punch with a hydraulic clicker. All five punches do not delaminate.
Delamination should occur even in one punch ×
[0032]
(7) Activated carbon permeability evaluation test counting method filtration tester test piece; 130 mmφ (90 mmφ)
Flow velocity: 18.1 m / min 5.0 cm / sec
10. Particle size supplied; air dust counter; particle size in two sections; 0.3-0.5μ, 0.5-1.0μ, -20μ, 2.0-5.0μ, 5.0μ or more (evaluation)
0/50 ○ No particle passing through 5.0 μm or more of passing particle size, and none of 50 or more passing
> 1/50 × passed one or more
[0033]
Table 1 was prepared as follows based on the above measurements and evaluations.
[0034]
[Table 1]

[0035]
From Table 1 above, it can be seen that the nonwoven fabric according to the example of the present invention is more excellent on average than the nonwoven fabric of the comparative example in terms of workability and activated carbon permeability as well as the amount of retained dust.
[0036]
【The invention's effect】
As described above, the present invention is obtained by bonding a long fiber layer and a short fiber layer to each other with a heat-fusible fiber, and has a pore size of at least 150 μm and a peel strength of 20.0 N / cm ² or more. It is a non-woven fabric that has the property of removing fine dust in the long fiber layer and preventing the activated carbon from coming off, preventing the fine particles of the activated carbon from coming off, and being less likely to be clogged by dust, etc., and is extremely excellent for canister filters. It has a practical effect.
In particular, if the short fiber layer and long fiber layer are bonded through needle processing, it is difficult to reduce the size of the hole formed by the needle in the spun bond even in the final resin bond, which hinders the function as a canister filter. Adhesion with adhesive fibers improves pore size control and exerts the effect of not exposing activated carbon fine particles to the outside. At the same time, needle punching and resin adhesion are used in combination to form short fiber layers, resulting in hair loss and It has the effect of eliminating displacement and improving dimensional stability.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a nonwoven fabric according to the present invention.
[Explanation of symbols]
1 long fiber layer 2 short fiber layer 3 heat-fusible fiber

Claims (7)

21. A nonwoven fabric in which a fiber layer of polyester long fibers and a fiber layer of polyester short fibers obtained by a spunbond method are bonded with heat-fusible fibers, wherein the maximum pore size of the nonwoven fabric is 150 μm or less and the peel strength is 20. 0N / cm ² or more in processability and filter excellent in canister nonwoven filter, characterized in that. A fiber layer of polyester long fibers obtained by a spunbond method and a nonwoven fabric in which a fiber layer made of polyester short fibers are bonded by a heat-fusible fiber, and the maximum pore size of the nonwoven fabric is 150 μm or less, A nonwoven fabric for a canister filter excellent in workability and filterability, having a collection efficiency of at least 95% and a pressure loss of 150 Pa or less, and having a peel strength of 20.0 N / cm ² or more. ^{3. The} polyester filament according to claim 1, wherein the fineness of the polyester filament obtained by the spun bond method is in a range from 1.0 dtex to 6.0 dtex, and a basis weight is in a range from 20 g / m ² to 100 g / m ² . Nonwoven fabric for canister filters with excellent processability and filterability. The constituent fineness of the fiber layer of the polyester short fiber is composed of fine fineness and large fineness, the fine fineness ranges from 1.0 decitex to 5.0 decitex, and the fine fineness ranges from 5.0 decitex to 10.0 decitex. , mixed fiber percentage of fine / thick fibers is 50/50 wt% to 30/70 wt%, and, processing basis weight according to claim 1, wherein in the range of 150 g / ^{m 2} of 600 g / ^{m 2} Nonwoven fabric for canister filters with excellent properties and filterability. 5. The processability and filterability according to claim 1, 2, 3 or 4, wherein the fiber layer of polyester short fibers is formed by entanglement of a short fiber web composed of a mixture of fineness and fineness and further by resin bonding. Non-woven fabric for canister filter. 6. The processability and filterability according to claim 5, wherein the adhesive resin constituting the fiber layer of the polyester short fiber is an acrylic resin, and the amount of adhesion is in the range of 5% by mass to 20% by mass with respect to the fiber layer. Nonwoven fabric for canister filters. The heat-fusible fiber is made of a low-melting polyester resin, has a melting point in the range of 120 ° C. to 200 ° C., is formed into a hot melt sheet, and has a basis weight in the range of 10 g / m ² to 100 g / m ^2. Item 7. A nonwoven fabric for a canister filter having excellent workability and filterability according to any one of Items 1 to 6.

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