JP7229165B2 - Filter and filter manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a filter and a method for manufacturing the filter , and more particularly to a filter using a non-woven fabric used to prevent contamination of cooker hoods, ventilation fans, vents, and the like, and a method for manufacturing the filter.

Conventionally, a nonwoven fabric made of synthetic fibers has been used as a filter for preventing contamination of range hoods and ventilation fans.

For example, in Japanese Patent Laid-Open No. 2003-236320, after forming a fiber web (also called card) by mixing fusible synthetic fibers such as polyester fibers and non-fusible fibers such as rayon fibers, A nonwoven fabric manufactured by spraying or the like a binder (adhesive agent, binding agent) for bonding fibers made of a flammable thermoplastic resin to a fiber web, and a filter using the same are disclosed. A flame retardant such as a phosphorus-based water-soluble flame retardant compound is added to the binder, and when such a filter is used as a filter for preventing stains on range hoods and ventilation fans, the flame retardant is added to the non-woven fabric of the filter. Its presence throughout prevents it from burning easily even if a fire touches the filter.

However, in the non-woven fabric using a binder as in Japanese Patent Laid-Open No. 2003-236320, the binder is applied only to the surface layer of the non-woven fabric and does not penetrate sufficiently to the inner side of the non-woven fabric, resulting in uneven flame retardancy. Sometimes. In addition, when the binder is sufficiently penetrated to the inner side to enhance the flame retardancy of the inner side, a large amount of binder is required, which not only increases the manufacturing cost, but also increases the gap between the fibers. There is a risk that the air permeability will decrease due to being filled with or becoming narrow. When a non-woven fabric is used as a filter, if the air permeability is lowered, the function as a filter may be adversely affected.

In addition, since such a nonwoven fabric is composed of fibers and a binder, the absolute amount of fibers constituting the nonwoven fabric per unit basis weight decreases, making the nonwoven fabric bulky and reducing the so-called stiffness (flexural rigidity, elasticity, etc.). When it is desired to strengthen the shape retention related to the product, it is necessary to increase the weight per unit area. In particular, when the installation area is large, such as a range hood, which is attached to the ceiling position or its slope, if there is no stiffness, the non-woven fabric will be bent in the middle during installation, and it will take time to install. be.

Therefore, in Japanese Patent Application Laid-Open No. 2006-281108, the fibers are bonded together without using a binder like Japanese Patent Application Laid-Open No. 2003-236320, and the heat fusibility of the fibers themselves constituting the nonwoven fabric is used. A nonwoven fabric using a bonding method called a thermal bond method and a filter using the same are disclosed.

Japanese Patent Application Laid-Open No. 2003-236320 Japanese Patent Application Laid-Open No. 2006-281108

However, in the case of the thermal bonding method as in Patent Document 2, if heat bonding is performed by contact heating in which the heat source is directly brought into contact with the fibers, the nonwoven fabric is compressed by the heat source, resulting in a decrease in bulkiness. If the bulkiness is too low, the density of the fibers in the nonwoven fabric will increase too much, which may lead to a decrease in the breathability of the nonwoven fabric or an excessive stiffness to make the nonwoven fabric hard.

In addition, for example, when heat bonding is performed by non-contact heating such as an air-through method (a method of applying hot air to the fiber web) in which the heat source does not directly contact the fibers, the nonwoven fabric is not compressed, but the fiber web is not compressed. Depending on how the hot air is applied and the heat history, there may be places where the thermal bonding between the fibers is uneven. In particular, when a plurality of fiber webs are laminated and thermally bonded by non-contact heating, there are cases where the fiber webs are not properly bonded to each other and the bonding strength of the laminated portions is weak.

Such problems also exist in nonwoven fabrics used for applications other than dirt-preventing filters such as cooker hoods and ventilation fans.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a filter using a nonwoven fabric having sufficient stiffness and having strong stiffness , and a method for manufacturing the filter . and

In order to achieve the above objects, the first aspect of the present invention provides a filter having a core-sheath structure in which the sheath is made of low-melting-point polyester and the core is made of high-melting-point polyester having a higher melting point than the low-melting-point polyester. A filter for preventing stains on range hoods or ventilators using a non-woven fabric made of polyester fibers and the remaining other fibers, wherein the non-woven fabric is a non-woven fabric body in which composite polyester fibers and the remaining other fibers are integrated The nonwoven fabric body contains 40% by weight or more and 80% or less by weight of the composite polyester fiber in the total amount of 100% by weight of the nonwoven fabric body, and the bending resistance of the nonwoven fabric body in the first direction is 50 mN cm or more and 120 mN cm or less. , the bending resistance in the second direction perpendicular to the first direction is 20 mN·cm or more and 100 mN·cm or less.

With this configuration, the fibers are sufficiently bonded together and the nonwoven fabric has a strong stiffness.

In the filter according to the second aspect of the present invention, in the configuration of the invention according to the first aspect, the nonwoven fabric body has a basis weight of 40 g/m ² or more and 60 g/m ² or less, and the bending resistance in the first direction and the bending resistance in the second direction The ratio of the bending resistance to the bending resistance in the direction (the bending resistance in the first direction/the bending resistance in the second direction) is in the range of more than 1.0 to 4.0 or less.

With this configuration, it becomes easier to cut the nonwoven fabric into the expected size and to form a desired adhesive pattern on the filter using the nonwoven fabric.

A filter according to a third aspect of the present invention, in the structure of the invention according to the first aspect or the second aspect, contains flame-retardant fibers for the remainder.

With this configuration, flame retardancy can be imparted to the nonwoven fabric.

A filter according to a fourth aspect of the present invention is the configuration of the invention according to the third aspect, wherein the flame-retardant fibers are flame-retardant acrylic fibers.

With this configuration, the nonwoven fabric exhibits sufficient flame retardancy.

According to a fifth aspect of the present invention, in the configuration of the invention according to any one of the first to fourth aspects, the low melting point polyester has a melting point of 100° C. or more and 140° C. or less, and the composite polyester fiber is a composite It contains 20% by weight or more and 50% by weight or less of low-melting polyester in 100% by weight of the total amount of polyester fibers.

This configuration results in a fully integrated nonwoven fabric body.

A method for producing a filter according to the sixth aspect of the present invention comprises a composite polyester fiber having a core-sheath structure in which the sheath is made of low-melting polyester and the core is made of high-melting polyester having a higher melting point than the low-melting polyester, and the remainder of A method for producing a filter according to any one of the first to fifth aspects for preventing stains on range hoods or ventilation fans, using a non-woven fabric made of other fibers, comprising: A preparation step of preparing a composite polyester fiber so that it is contained in a total amount of 100% by weight of 40% by weight or more and 80% by weight or less, a mixing step of uniformly mixing the mixed fibers, and forming a fiber web with the mixed fibers A web forming step, a thermal bonding step of subjecting the fibrous web to a non-contact heating device to thermally bond fibers contained in the fibrous web to obtain a nonwoven fabric base, and compressing the nonwoven fabric base in the thickness direction. It includes a compression step and a reheating step of subjecting the compressed nonwoven fabric raw material to a non-contact heating device to obtain a nonwoven fabric.

With this configuration, bulkiness can be improved by the reheating process.

According to a seventh aspect of the present invention, there is provided a filter manufacturing method according to the sixth aspect, wherein the web forming step includes a step of laminating a plurality of fiber webs.

By configuring in this way, it is possible to laminate the fiber webs in a plurality of arrangement directions.

According to the eighth aspect of the present invention, the method for producing a filter according to the sixth aspect or the seventh aspect of the present invention is characterized in that the remainder contains flame-retardant fibers.

With this configuration, flame retardancy can be imparted to the nonwoven fabric.

According to a ninth aspect of the present invention, in the method for manufacturing a filter according to the eighth aspect, the flame-retardant fibers are flame-retardant acrylic fibers.

With such a configuration, a nonwoven fabric exhibiting sufficient flame retardancy can be produced.

In the method for producing a nonwoven fabric according to the tenth aspect of the present invention, in any one of the sixth to ninth aspects, the reheating step includes heating at a temperature of 100° C. or higher and 200° C. or lower for a heating time of 5 seconds. It is carried out under the conditions of 10 minutes or less.

With this configuration, the improvement in bulkiness is stabilized.

As described above, the filter according to the first aspect of the present invention is a nonwoven fabric having sufficient fiber-to-fiber bonding and high stiffness, and is therefore suitable for manufacturing filters.

The filter in the second aspect of the present invention, in addition to the effects of the invention in the first aspect, makes it easy to cut the nonwoven fabric to the assumed size and to easily form a desired adhesive pattern on the filter using the nonwoven fabric. Therefore, the nonwoven fabric is suitable for manufacturing filters.

Since the filter in the third aspect of the present invention can impart flame retardancy to the nonwoven fabric in addition to the effects of the invention in the first aspect or the second aspect, the filter preferably has flame retardancy. It becomes a nonwoven fabric suitable for the production of.

The filter according to the fourth aspect of the present invention is a nonwoven fabric that exhibits sufficient flame retardancy in addition to the effects of the invention according to the third aspect, so it is possible to manufacture a filter with sufficient flame retardancy. becomes.

The filter according to the fifth aspect of the present invention, in addition to the effects of the invention according to any one of the first to fourth aspects, becomes a fully integrated nonwoven fabric body, so it is more suitable for manufacturing filters. non-woven fabric.

In the filter manufacturing method according to the sixth aspect of the present invention, the bulkiness can be improved by the reheating step, so a nonwoven fabric having high bulkiness and high stiffness can be manufactured.

The method for manufacturing a filter according to the seventh aspect of the present invention, in addition to the effects of the invention according to the sixth aspect, is capable of laminating a plurality of fiber webs in the arrangement direction, and in one fiber web, there are no missing or see-through fibers. Even if there is a defect, by laminating a plurality of layers, the finally obtained nonwoven fabric is suppressed from missing or see-through. In addition, by laminating a plurality of layers, it becomes easy to adjust bulkiness and air permeability to desired ranges. Furthermore, it is also possible to change the texture and functionality of the nonwoven fabric between the front and back.

In addition to the effects of the invention in the sixth or seventh aspect, the method for manufacturing a filter in the eighth aspect of the present invention can impart flame retardancy to the nonwoven fabric, and therefore has flame retardancy. can obtain a nonwoven fabric suitable for the production of a preferred filter.

The method for producing a filter in the ninth aspect of the present invention can produce a nonwoven fabric exhibiting sufficient flame retardancy in addition to the effects of the invention in the eighth aspect, and thus has sufficient flame retardancy. Filters can be manufactured.

The method for manufacturing a filter according to the tenth aspect of the present invention has the effect of the invention according to any one of the sixth to ninth aspects, and in addition, the improvement in bulkiness is stabilized, so the bulkiness is further improved. A nonwoven fabric with high stiffness can be produced.

It is a mimetic diagram showing a partial enlarged structure of the nonwoven fabric by an embodiment of this invention. It is a flow chart which shows a manufacturing process of a nonwoven fabric by an embodiment of this invention.

The nonwoven fabric according to the embodiment of the present invention comprises composite polyester fibers having a core-sheath structure in which the sheath is made of low-melting polyester and the core is made of high-melting-point polyester having a higher melting point than the low-melting-point polyester, and the remainder of other fibers. The nonwoven fabric body has a nonwoven fabric body in which conjugated polyester fibers and the remaining other fibers are integrated, and the nonwoven fabric body contains 40% by weight or more and 80% by weight of the conjugated polyester fibers in the total amount of 100% by weight of the nonwoven fabric body. Including the following, the bending resistance of the fibers of the nonwoven fabric body in the first direction is 50 mN cm or more and 120 mN cm or less, and the bending resistance in the second direction orthogonal to the first direction is 20 mN cm or more and 100 mN · cm or less.

With such a structure, the fibers are sufficiently bonded and the nonwoven fabric has a strong stiffness, so that the nonwoven fabric is suitable for the production of filters.

FIG. 1 is a schematic diagram showing a partially enlarged structure of a nonwoven fabric according to an embodiment of the present invention.

Referring to the figure, nonwoven fabric body 11 constituting nonwoven fabric 1 is formed by integrating composite polyester fibers 2a and 2b and flame-retardant acrylic fiber 3 as the remaining other fiber.

The composite polyester fibers 2a and 2b are made by coating the surface of high-melting polyester with polyester having a lower melting point than the polyester. That is, the composite polyester fibers 2a and 2b have the sheath portions 4a and 4b made of low-melting polyester (for example, polyethylene terephthalate with a melting point of 110°C; PET), and the core portions 5a and 5b made of high-melting polyester having a higher melting point than the low-melting polyester ( For example, it has a core-sheath structure made of PET having a melting point of 260°C. The core portions 5a and 5b (high melting point polyester) are included in 60% by weight in the total amount of 100% by weight of the composite polyester fibers 2a and 2b.

Further, in the total amount of 100% by weight of the nonwoven fabric body 11, the composite polyester fibers 2a and 2b are contained in 70% by weight, and the flame-retardant acrylic fiber 3 is contained in 30% by weight.

Here, the nonwoven fabric main body 11 is formed by laminating a random web on a parallel web. Then, as shown in FIG. 1, part of the surface of the sheath 4b of the composite polyester fiber 2b positioned above is fused (melted in the manufacturing process and state).

In addition, the flame-retardant acrylic fiber 3 is uniformly contained in the entire nonwoven fabric body 11, and the flame-retardant acrylic fiber 3 and the sheath portion 4b of the composite polyester fiber 2b are separated from each other at the bonding point 6b with the composite polyester fiber 2b. A part of the surface is fused.

Thus, the fibers forming the nonwoven fabric body 11 are sufficiently bonded.

Furthermore, the bending resistance in the fiber flow direction as the first direction of the nonwoven fabric body 11 is 79.1 mN cm, and the bending resistance in the width direction as the second direction perpendicular to the flow direction is It is 50.0 mN·cm.

The bending resistance refers to the bending resistance measured and calculated according to JIS L 1913:2010 "41.5° cantilever method". The higher the bending resistance, the more difficult it is for the non-woven fabric to bend. In addition, the lower the bending resistance, the more easily the nonwoven fabric bends. If the bending resistance of the nonwoven fabric main body 11 in the machine direction and the width direction is sufficient, the nonwoven fabric will be appropriately stiff.

The bending resistance ratio between the bending resistance in the machine direction and the bending resistance in the width direction (bending resistance in the machine direction/bending resistance in the width direction) is 1.6.

Next, a manufacturing process for obtaining such a nonwoven fabric will be described.

FIG. 2 is a flow chart showing the manufacturing process of the nonwoven fabric according to the embodiment of the invention.

Referring to the figure, step 31 is a preparatory step of preparing a composite polyester fiber so that the composite polyester fiber is contained in an amount of 40% by weight or more and 80% by weight or less in 100% by weight of the total amount of fibers to be blended.

In addition, other fibers are prepared in an amount of 20% by weight or more and 60% by weight or less of the remainder. In this embodiment, flame-retardant acrylic fiber is used.

Raw cotton of fibers to be blended is prepared.

Next, step 32 is a mixing step for uniformly mixing the fibers to be compounded.

The raw cotton of the fibers to be blended is loosened, and each of the fibers to be blended is weighed and mixed as described above. In this manner, each of the fibers is evenly distributed throughout the mixed fibers.

Next, step 33 is a web forming step of forming a fibrous web from the mixed fibers.

The mixed fibers are passed through a plurality of rolls or the like to form a sheet-like fibrous web. At this time, any fiber web such as a parallel web, a random web, or a cross web may be formed. In the present embodiment, a parallel web having a high strength in the direction of flow and a random web having a substantially random fiber arrangement direction and a high bulkiness are formed. , including laminating a plurality of these fibrous webs.

Next, step 34 is a thermal bonding step of subjecting the fibrous web to a non-contact heating device to thermally bond the fibers contained in the fibrous web to obtain a nonwoven fabric base.

In this embodiment, a so-called air-through method is used. That is, as a non-contact type heating device, a hot air device for blowing heated air as hot air onto the fiber web is used under ordinary conditions.

As a result, the low-melting-point polyester in the sheath of the composite polyester fiber contained in the fiber web is melted and hardened when cooled, so that the fibers contained in the fiber web are thermally bonded to each other to obtain an original nonwoven fabric.

Next, step 35 is a compression step of compressing the original nonwoven fabric in the thickness direction.

The raw nonwoven fabric is wound up by a turret and compressed into a roll.

Next, step 36 is a reheating step in which the compressed nonwoven fabric raw material is subjected to a non-contact heating device to obtain a nonwoven fabric.

The compressed nonwoven fabric base is unwound and heated using a hot air device, for example, at a heating temperature of 100° C. or higher and 200° C. or lower for a heating time of 5 seconds or longer and 10 minutes or shorter.

In this way, it is possible to obtain the above-described nonwoven fabric of the present invention, which has a high bulkiness and a strong stiffness, and has a high bonding force between fibers even in a structure in which a plurality of fiber webs are laminated. .

The reason why the nonwoven fabric of the present invention obtained in this way has high bulkiness and high stiffness, and in particular, has a high bonding force between fibers even in a structure in which a plurality of fiber webs are laminated, is not clear. No, but it is speculated as follows.
As described above, in the nonwoven fabric base material obtained by the air-through method in the thermal bonding step, the fibers are bonded together, but at this stage there are many areas where the bonding between the fibers is insufficient.

Therefore, when the original nonwoven fabric is first compressed in the thickness direction in the compression step, force is applied to the fibers, so that the fibers are maintained in a bent state. As a result, a portion in which the fibers are in contact with each other is generated.

When the compressed nonwoven fabric material is reheated in the reheating step, the thermal motion of the bent fibers becomes active, so that the fibers tend to return to the state before they were bent. On the other hand, when the fibers are in contact with each other, the low-melting-point polyester of the sheath of the composite polyester fiber is melted and bonded by being heated. That is, there are more bond points in the nonwoven after compression and reheating than there are in the bulk nonwoven before compression. Therefore, the integrity of the nonwoven fabric is improved as a whole due to the bonding between the fibers.

On the other hand, when the compressed nonwoven fabric material is reheated, the fibers are not in contact with each other, and the fibers are in contact but separated before being thermally bonded. Since it returns to the state before bending, bulkiness is restored.

It is speculated that the nonwoven fabric of the present invention has excellent properties due to such a mechanism.

In addition, since the nonwoven fabric of the present invention has flame retardancy due to the inclusion of flame retardant fibers, it can be suitably used as a filter for preventing stains on range hoods and ventilation fans.

In addition, as a filter for preventing stains such as range hoods and ventilation fans, the thickness of the nonwoven fabric is preferably in the range of 0.2 mm to 20.0 mm, and is in the range of 2.5 mm to 8.0 mm. is more preferred. When a filter is used for a range hood, ventilation fan, or the like, air containing oil stains passes through the nonwoven fabric of the filter and is filtered, so such a nonwoven fabric preferably has high air permeability and high bulkiness. When the thickness of the nonwoven fabric is set within the above numerical range, it becomes possible to achieve both air permeability and bulkiness, and it can be used more preferably as a dirt-preventing filter for cooker hoods, ventilation fans, and the like.

Next, step 37 is a folding step and a winding step for forming the nonwoven fabric into a desired shape as necessary.

First, the nonwoven fabric is cut into a desired length and width by a cutter device. A desired number of cut non-woven fabrics are accumulated and folded by a folding device or wound into a roll by a winding device to form a shape convenient for distribution or product sales.

In the above embodiment, the nonwoven fabric is composed only of the nonwoven fabric main body. A non-woven fabric (or non-woven fabric structure) is constructed by, for example, transferring the adhesive to the non-woven fabric body by preparing the coated release film separately and overlapping the adhesive-coated surface of the release film with the non-woven fabric body. can be That is, the main body of the nonwoven fabric is a portion that is substantially the base of the nonwoven fabric, and is a portion composed of the blended fibers (composite polyester fibers and other fibers of the remainder).

In the above embodiment, the prescribed PET was used for both the low-melting polyester and the high-melting polyester. Examples thereof include polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT). Different types of polyester may be used as the low melting point polyester and the high melting point polyester. Also, a copolymer component may be included in the polymer structure to improve the properties of the fiber.

Furthermore, although the melting point of the low melting point polyester is 110° C. in the above embodiment, the melting point is preferably 100° C. or higher and 140° C. or lower, more preferably 110° C. or higher and 120° C. or lower. At this time, the composite polyester fiber preferably contains 20% to 50% by weight, more preferably 30% to 45% by weight, of the low-melting polyester in the total amount of 100% by weight of the composite polyester fiber.

By configuring in this way, the fibers are sufficiently bonded to form a sufficiently integrated nonwoven fabric main body, so that the nonwoven fabric is more suitable for manufacturing a filter.

Furthermore, in the above embodiment, the melting point of the high-melting polyester was 260° C., but the melting point should be higher than the low-melting polyester. However, the high melting point polyester may be one that does not substantially melt.

Furthermore, in the above embodiments, the low-melting polyester directly covers the high-melting polyester to form a core-sheath structure. Even if it is covered with a sheath or is of a side-by-side type, it is substantially included in the present invention as a core-sheath structure.

Furthermore, in the above embodiments, flame-retardant acrylic fibers are used as flame-retardant fibers, but other flame-retardant fibers such as flame-retardant polyester fibers may be used. That is, the balance contains flame-retardant fibers. Since flame retardancy can be imparted to the nonwoven fabric by configuring in this way, the nonwoven fabric is suitable for manufacturing a filter that preferably has flame retardancy.

The flame-retardant acrylic fiber mentioned above refers to acrylic fiber having flame-retardant properties (synthetic fiber mainly composed of acrylonitonyl). For example, acrylic fiber obtained by blending and kneading a flame retardant, contains halogen such as chlorine in its composition, and emits halogen gas when burning to extinguish the atmosphere. There is an acrylic synthetic fiber (modacrylic fiber) with By using such a flame-retardant acrylic fiber as the flame-retardant fiber, a non-woven fabric exhibiting sufficient flame-retardancy can be obtained, so that a filter having sufficient flame-retardancy can be produced.

Also, the remainder mentioned above may contain other fibers as well as flame-retardant fibers. For example, rayon fiber, polyvinyl alcohol (PVA) fiber, etc. can be mentioned, and when these fibers are included as other fibers, dripping of molten resin during combustion can be prevented.

Furthermore, the remainder mentioned above may consist of other fibers without containing the flame-retardant fibers. Even when configured in this manner, the nonwoven fabric can be suitably used as a nonwoven fabric used for filters that do not require flame retardancy, such as filters for vents. In addition, the other fibers may be of a single type, or may be of a plurality of types.

Incidentally, the term "flame-retardant" refers to a material that is difficult to ignite and that, when ignited, burns at a slow speed. 11A-2003, preferably Category 3 by the flammability test.

Furthermore, in the above embodiment, the composite polyester fiber was contained in an amount of 70% by weight in the total amount of 100% by weight of the non-woven fabric body, but it may be contained in an amount of 40% by weight or more and 80% by weight or less. By configuring in this way, the fibers are sufficiently bonded to each other.

Furthermore, in the above embodiment, the machine direction is used as the first direction of the nonwoven fabric main body, but the first direction is the nonwoven fabric main body (including the nonwoven fabric and the state of being a filter) with the highest bending resistance. The high direction is usually the warp or machine direction, which is the manufacturing direction (machine direction) of the nonwoven fabric. Also, the second direction is a direction orthogonal to the first direction, and is usually the horizontal direction or the width direction.

Furthermore, in the above embodiment, the bending resistance in the machine direction and the width direction of the nonwoven fabric body is a specific numerical value, but when the bending resistance in the first direction of the nonwoven fabric body is 50 mN cm or more and 120 mN cm or less, It is preferable that the bending resistance in the second direction, which is the direction orthogonal to the first direction, is 20 mN·cm or more and 100 mN·cm or less.

Furthermore, in the above embodiment, the ratio of the bending resistance between the bending resistance in the machine direction (first direction) and the bending resistance in the width direction (second direction) (bending resistance in the machine direction/stiffness in the width direction) Softness) was 1.6, but it is preferably in the range of more than 1.0 to 4.0 or less. If the bending resistance ratio is greater than 1.0, the bending resistance in the machine direction is higher than the bending resistance in the width direction. Since the fibers are less likely to stretch in the machine direction of the nonwoven fabric, the dimensional change after cutting is relatively small, making it easier to cut the nonwoven fabric to the expected size. Further, if the bending resistance ratio is 4.0 or less, the bending resistance in the machine direction is not too higher than the bending resistance in the width direction, and the non-woven fabric is subjected to adhesion processing while applying a pulling force to some extent in the machine direction. In such a case, it becomes difficult for the fibers to shrink in the width direction of the nonwoven fabric, so that it becomes easier to form an expected adhesion pattern. Therefore, the nonwoven fabric is suitable for manufacturing a filter to which such cutting and adhesive patterns are applied. Of course, the bending resistance ratio may be 1.0. In order to sufficiently exhibit such effects, the nonwoven fabric body preferably has a basis weight of 40 g/m ² or more and 60 g/m ² or less.

Furthermore, in the above-described embodiments, the nonwoven fabric main body is configured by laminating a parallel fiber web and a random fiber web. You may laminate|stack several pieces which carried out. By configuring in this way, it is possible to laminate the fiber webs in a plurality of arrangement directions. As a result, even if a single fiber web has missing or see-through fibers, the non-woven fabric finally obtained by laminating a plurality of layers can suppress the missing or see-through, and can easily adjust the bulkiness and air permeability to the desired range. It is also possible to change the texture and functionality of the nonwoven fabric on the front and back.

The nonwoven fabric body may be formed by, for example, laminating different types of fiber webs (parallel web, random web, etc.) as in the present embodiment, or laminating the same type of fiber webs (random web, random web, etc.). Alternatively, it may be made of a single type of fiber web without lamination. Compared to parallel webs, laminating a plurality of random webs increases the number of bonding points per unit basis weight through the subsequent heat bonding process and reheating process, so bulkiness can be improved. In this way, it is possible to adjust performance such as bulkiness.

Furthermore, in the above embodiment, in addition to the composite polyester fiber, the flame-retardant acrylic fiber was prepared in the preparation step, but at least the composite polyester fiber and the rest of the fibers described above should be prepared.

Furthermore, in the above-described embodiment, the fibers to be blended are uniformly mixed in the mixing step, but it is sufficient that the fibers are dispersed to the extent that they are considered to be substantially uniform.

Furthermore, in the above embodiment, a hot air device was used as a non-contact heating device in each of the heat bonding step and the reheating step. Good if

Furthermore, in the above embodiment, the reheating process is performed under the conditions of the predetermined heating temperature and heating time, but it may be performed under other conditions. It should be noted that the reheating step is preferably performed under the above-described predetermined conditions, and by doing so, the improvement in bulkiness is stabilized, so it is possible to produce a nonwoven fabric with higher bulkiness and strong stiffness. can be done. Further, the heating temperature in the reheating step is more preferably higher than the melting point of the low-melting polyester used.

Alternatively, the nonwoven fabric obtained by the reheating step may be coated with an adhesive in a desired pattern or printed with a pattern as described above.

Furthermore, in the above embodiments, the nonwoven fabric was manufactured by a specific manufacturing method, but it may be manufactured by another manufacturing method.

The present invention will be specifically described below based on examples. It should be noted that the embodiments of the present invention are not limited to the examples.

Test specimens of Examples and Comparative Examples of the present invention were prepared, and a bending resistance test for measuring bending resistance and a flammability test for evaluating performance during combustion were conducted on these specimens.

<Configuration of test body>
As test pieces, nonwoven fabrics (filters) of Examples 1 to 7, Comparative Examples 1 to 4, and Reference Example 1 having the configurations shown in Table 1 below were prepared.

尚、表中の繊維径の単位「ｄ」はデニールである。

The unit "d" of the fiber diameter in the table is denier.

In addition, the units of numbers in the tables are g/m ² unless otherwise specified.

In addition, blanks in the table indicate substantially no fiber type. In addition, "-" in Comparative Examples 1 to 4 in the reheating process in the table indicates that the reheating process cannot be considered because these are configured using a method of binding fibers with a binder.

In addition, the "resin/flame retardant (binder)" in the table refers to a halogen-based flame retardant added to a thermoplastic resin to give it a binder function that binds fibers together and a flame retardant function during combustion. It is.
Furthermore, the "low-melting point PET" of the sheath of the "composite PET fiber" in the table had a melting point of 110°C to 140°C.

Examples 1-7 were prepared using the manufacturing method of the present invention described above. That is, the nonwoven fabrics of Examples 1 to 7 were improved in bulkiness and stiffness through compression and reheating steps after obtaining the original nonwoven fabric by the air-through method.

Incidentally, Reference Example 1 was prepared in the state of a nonwoven fabric raw material without performing the reheating step, with the same fiber composition as that of Example 1 described above.

Further, Comparative Examples 1 to 4 are all conventional nonwoven fabrics (commercially available) using a binder.

<Bending resistance test and range hood mounting test>
For the specimen prepared as described above, first, as a bending resistance test, the bending length (unit: mm) was measured in accordance with JIS-L-1096 A method "45 ° cantilever method", and JIS L 1913 : 2010 "41.5° cantilever method" was used to calculate the bending resistance (unit: mN·cm).

In addition, a range hood attachment test was conducted to confirm the mountability to the range hood.
First, each test piece was cut to a test piece size of 60 cm x 36 cm, and a filter immediately after being prepared as "before folding" was prepared. The product was packaged in the folded state and stored for one month, which was prepared as "one month after bending".

The filter for each of these test pieces was attached to a range hood of "BDR-3HL-601BK" manufactured by Fuji Kogyo Co., Ltd. to confirm the mountability.

The results were as shown in Table 2 below.

尚、剛軟度は以下の式により算出した。

The bending resistance was calculated by the following formula.

G=m×C ³ ×10 ⁻³
In the formula, G: bending resistance (mN·cm), m: mass per unit area of test piece (g/m ² ), that is, basis weight, and C: total average bending length (cm). Note that in this formula, the free fall acceleration of 9.81 m/ ^s2 is rounded to 10 m/ ^s2 .

In addition, as an evaluation of the attachment to the range hood, "○" in the table "before bending" indicates that the filter has moderate stiffness and is suitably attached to the range hood, and "×" indicates that the filter This indicates that it was not suitable for attaching to the range hood due to its lack of stiffness. In addition, "○" for "one month after bending" indicates that there was no gap between the filter and the range hood when attached to the range hood, or even if there was a small gap, it was suitable. ” indicates that the filter was unsuitable because creases remained in the filter and a gap was generated between the filter and the range hood when it was attached to the range hood.

Referring to Table 2, Examples 1 to 7 have bending resistances in the machine direction of 79.1 mN·cm, 51.5 mN·cm, 69.1 mN·cm, 54.7 mN·cm, and 89 mN·cm, respectively. 9 mN cm, 73.5 mN cm, and 117.2 mN cm, and the bending resistance in the width direction is 50.0 mN cm, 20.3 mN cm, 42.4 mN cm, 51.8 mN cm, respectively. They were 22.9 mN·cm, 20.6 mN·cm, and 98.6 mN·cm. Therefore, unlike conventional nonwoven fabrics (Comparative Examples 1 to 4), the nonwoven fabric of the present invention has a bending resistance of 50 mN cm or more and 120 mN cm or less in the first direction. It was confirmed that the bending resistance in a certain second direction was 20 mN·cm or more and 100 mN·cm or less.

Further, in Examples 1 to 7, the bending resistance ratio (bending resistance in the machine direction/bending resistance in the width direction) was 1.6, 2.5, 1.6, 1.1, 3.0, respectively. 9, 3.6, 1.2. Furthermore, in all of Examples 1 to 7, the attachability to the cooker hood was ◯ (preferred) regardless of whether it was "before folding" or "one month after folding". Therefore, it was confirmed that the nonwoven fabric and the filter of the present invention have a bending resistance ratio between the bending resistance in the first direction and the bending resistance in the second direction in the range of more than 1.0 to 4.0 or less. It was confirmed that a non-woven fabric filter having such a bending resistance ratio has appropriate stiffness and is suitable for attachment to a cooker hood.

Furthermore, comparing Example 1 and Reference Example 1, when the reheating step was not performed in the manufacturing process as in Reference Example 1, the bending resistance in the machine direction and the width direction was lower than that in Example 1. Although it was low and the attachment to the cooker hood before folding was inappropriate, when the reheating process was performed in the manufacturing process as in Example 1, the bending resistance in the flow direction and the width direction was increased. It was confirmed that all of them were within the preferable range and that the mountability to the cooker hood before folding was also preferable.

<Flame retardant test>
Using Examples 1 to 7 and a conventional Comparative Example 2 having the same basis weight as Example 1 and containing a binder and having flame retardancy, a flame retardancy test was performed to evaluate performance during combustion. rice field.

The results came to be shown in Table 3 below.

尚、表中、「難燃性」とは、ＪＡＣＡ Ｎｏ．１１Ａ－２００３燃焼試験に準拠して評価された性能を示す。

In the table, "flame-retardant" means JACA No. 11A-2003 flammability test.

In the table, "Flambe test" indicates whether or not the melted resin fell in the form of balls when each specimen was burned.

Furthermore, in the table, the "lighter flame spread test" indicates how the flame spreads, which was evaluated multiple times by cutting each test piece into strips, holding one end, and approaching the flame of a lighter from the other end. . In addition, "no unevenness in the spread of flame" indicates that the flame spread was good at any test location and the flame retardancy was good, and "unevenness in the spread of flame" indicates that the flame spread at least at any of the test locations. This indicates that the flame retardancy was uneven and not good.

Furthermore, in the table, "airflow rate" indicates the airflow rate (cc/cm ² /sec) measured according to JIS-L-1913 Frazier type.

Furthermore, in the table, "thickness" indicates the average thickness of the entire nonwoven fabric measured under a load of 0.8 g/cm ² and is a factor leading to bulkiness.

Furthermore, in the table, "peeling of the hook-and-loop fastener" indicates the performance when removing the non-woven fabric attached to the installation location using the hook-and-loop fastener. and whether fibers of the nonwoven fabric adhere to the hook-and-loop fastener side.

Then, from the results of "flame retardancy" in Table 3, all of Examples 1 to 7 containing flame-retardant acrylic fibers in the configuration satisfy Category 3 in terms of flame retardancy as in Comparative Example 2. That is, it was confirmed to have flame retardancy.

Further, from the results of the "Flambe test", it was confirmed that in any of Examples 1 to 7, as in Comparative Example 2, there was no dripping of molten resin during combustion.

Furthermore, from the results of the "lighter flame spread test", it was confirmed that in all of Examples 1 to 7, there was no unevenness in the flame spread during combustion, and that the flame retardancy of the entire nonwoven fabric was good compared to Comparative Example 2. rice field.

Furthermore, from the results of "airflow rate" and "thickness", it was confirmed that all of Examples 1 to 7 ensured sufficient airflow rate and bulkiness as a filter as in Comparative Example 2. rice field.

Furthermore, from the results of "peeling of the hook-and-loop fastener", it was confirmed that all of Examples 1 to 7 could be attached and removed satisfactorily when installed using the hook-and-loop fastener as in Comparative Example 2. .

INDUSTRIAL APPLICABILITY As described above, the nonwoven fabric, the filter using the same, and the method for producing the nonwoven fabric according to the present invention are suitable for preventing contamination of range hoods and ventilation fans, for example.

Claims (10)

A composite polyester fiber (2) having a core-sheath structure in which the sheath (4) is a low-melting polyester and the core (5) is a high-melting polyester having a higher melting point than the low-melting polyester, and the remaining other fibers ( 3) A filter for preventing stains on a range hood or a ventilation fan using a nonwoven fabric (1) consisting of
The nonwoven fabric comprises a nonwoven fabric body (11) in which the composite polyester fiber and the remaining other fiber are integrated,
The nonwoven fabric body contains 40% by weight or more and 80% by weight or less of the composite polyester fiber in a total amount of 100% by weight of the nonwoven fabric body,
The nonwoven fabric body has a bending resistance of 50 mN cm or more and 120 mN cm or less in a first direction, and a bending resistance of 20 mN cm or more and 100 mN cm or less in a second direction perpendicular to the first direction. , the filter . The nonwoven fabric body has a basis weight of 40 g/m ² or more and 60 g/m ² or less,
The bending resistance ratio between the bending resistance in the first direction and the bending resistance in the second direction (the bending resistance in the first direction/the bending resistance in the second direction) is more than 1.0 and 4.0 2. A filter according to claim 1, which is within the following range. 3. A filter according to claim 1 or claim 2, wherein the remainder comprises flame retardant fibers. 4. The filter of claim 3, wherein the flame retardant fibers are flame retardant acrylic fibers. The low melting point polyester has a melting point of 100° C. or higher and 140° C. or lower,
5. The filter according to any one of claims 1 to 4, wherein the composite polyester fiber contains 20% by weight or more and 50% by weight or less of the low-melting polyester in the total amount of 100% by weight of the composite polyester fiber. A composite polyester fiber (2) having a core-sheath structure in which the sheath (4) is a low-melting polyester and the core (5) is a high-melting polyester having a higher melting point than the low-melting polyester, and the remaining other fibers ( 3) A filter manufacturing method for manufacturing the filter according to any one of claims 1 to 5 for preventing stains on range hoods or ventilation fans, using the nonwoven fabric (1) consisting of
a preparation step (31) of preparing the composite polyester fiber so that the composite polyester fiber is contained in an amount of 40% by weight or more and 80% by weight or less in the total amount of 100% by weight of the fibers to be blended;
A mixing step (32) for uniformly mixing the fibers to be blended;
a web forming step (33) of forming a fibrous web from the mixed fibers;
a thermal bonding step (34) for obtaining a nonwoven fabric base by subjecting the fiber web to a non-contact heating device to thermally bond the fibers contained in the fiber web;
A compression step (35) for compressing the nonwoven fabric base in the thickness direction;
and a reheating step (36) to obtain the nonwoven fabric (1) by subjecting the compressed nonwoven fabric material to a non-contact heating device. 7. The method of manufacturing a filter according to claim 6 , wherein said web forming step includes a step of laminating a plurality of said fiber webs. The method for manufacturing a filter according to claim 6 or 7 , wherein the remainder contains flame-retardant fibers. 9. The method of manufacturing a filter according to claim 8 , wherein the flame-retardant fibers are flame-retardant acrylic fibers. The method for manufacturing a filter according to any one of claims 6 to 9 , wherein the reheating step is performed at a heating temperature of 100°C to 200°C and a heating time of 5 seconds to 10 minutes.

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