JP2014176797A - Filter element and method for production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter element for coarse dust removal excellent in filtration life or dust holding capability, having less pressure drop and having a new structure making it possible to reduce both weight and cost.SOLUTION: A filter element has a pleated filter medium and an end plate adhered to the edge face crossing with the pleat ridge line of the filter medium. The filter medium comprises a first nonwoven cloth bonded by a first heat adhesive fiber and having an average fineness of 5-30 dtex and thickness of 1-5 mm, and the end plate comprises a second nonwoven cloth bonded by a second heat adhesive fiber and having the average fineness of 5-30 dtex and thickness of 1-5 mm. The filter medium and end plate are bonded by the first heat adhesive fiber and/or the second one. Thereby, the above problem is solved.

Description

  The present invention is installed not only in a filter element for removing coarse dust used in an air conditioner in a living environment such as an automobile air conditioner or a home air cleaner, but also in a building, factory, office, etc. The present invention relates to a filter element for removing coarse dust used as a package filter, a fan coil unit, a central air conditioning filter unit or the like in an air cleaning device, and more particularly to a filter element having excellent filtration life or dust holding ability and low pressure loss.

  Conventionally, air filter base materials have been pleat-folded into home air purifiers, cabin filters that clean the outside and inside air of automobiles, and air purifiers that are placed on the ceiling of a vehicle cabin to clean the inside air. A filter element that retains its pleated shape by a shape-retaining member is used. The filter element of patent document 1 is known as such a filter element. According to the example of the document, as shown in FIG. 4, the nonwoven fabric substrate 111 having a relatively large average fineness in which the constituent fibers are bonded by the heat-adhesive fibers and having a thickness of about 1 mm, the heel height of 29 mm In addition, the pleating process 113 is applied to the pitch of 5 mm of the ridges, and the coarse shape removing members 112a and 112b made of a rigid nonwoven fabric are attached to the end surfaces crossing the pleated ridge direction through hot melt sheets. It is shown that a filter element 110 is formed. Here, as the rigid nonwoven fabric, for example, a plastic thin plate obtained by impregnating a spunbonded nonwoven fabric that is thermocompression-bonded in a spot shape is applied.

  Since the filter element of the filter element is made of the nonwoven fabric base material 111 having a relatively large average fineness in which the constituent fibers are bonded by the heat-adhesive fibers, the cost is lower than that of the filter medium for removing fine dust using ultrafine fibers. The filter element can be manufactured. However, there has been a demand for further cost reduction while maintaining the performance. In addition, a large amount of resin is used for the shape-retaining member, and it is necessary to affix a hot melt sheet to the entire shape-retaining member, which increases the weight of the shape-retaining member and the weight of the entire filter element. There has been a problem of increasing the size, and weight reduction has been demanded. Therefore, in this filter element 110, the material cost and processing cost of the shape-retaining members 112a and 112b, which only have an auxiliary function, compared with the nonwoven fabric base material 111 having an original filter function, are the cost of the entire filter element 110. As a result of intensive studies on the material and mounting structure of a new shape-retaining member that can be reduced in weight and cost, the present invention has been achieved.

JP 2007-38211 A JP 2004-89758 A

  An object of the present invention is to provide a filter element for removing coarse dust having a novel structure that is excellent in filtration life or dust holding capacity, has little pressure loss, and can be reduced in weight and cost.

  In order to solve the above-mentioned problem, in the invention according to claim 1, a filter element having a filter medium folded in pleats and an end plate bonded to an end face intersecting a ridge line of the pleat of the filter medium, the filter medium Consists of a first non-woven fabric with an average fineness of 5-30 dtex and a thickness of 1-5 mm, bonded by a first heat-bonding fiber, and the end plate is bonded by a second heat-bonding fiber, It consists of the 2nd nonwoven fabric whose average fineness is 5-30 dtex, and thickness is 1-5 mm, and the said filter medium and the said end plate adhere | attached by the 1st heat bondable fiber or / and the 2nd heat bondable fiber The filter element characterized by the above is used as the solution.

  In the invention which concerns on Claim 2, it is a manufacturing method of the filter element which adhere | attaches an end plate to the end surface which cross | intersects the pleat ridgeline of the said filter medium with respect to the filter medium folded by pleat, Comprising: The said filter medium is 1st heat | fever. It consists of a first nonwoven fabric with an average fineness of 5 to 30 dtex and a thickness of 1 to 5 mm bonded by an adhesive fiber, and the end plate is bonded by a second thermal adhesive fiber and has an average fineness of 5 It is composed of a second non-woven fabric having a thickness of 30 dtex and a thickness of 1 to 5 mm, and the filter medium and the end plate are bonded with the first heat-adhesive fiber or / and the second heat-adhesive fiber. This is a method for manufacturing a filter element.

  According to the present invention, it has become possible to provide a filter element for removing coarse dust having a novel structure that has excellent filtration life or dust holding capacity, low pressure loss, and can be reduced in weight and cost.

It is a perspective view which shows an example of the filter element of this invention. In addition, it is a diagram illustrating a mode in which the end plate is mounted in the direction of arrow A. It is a schematic cross section of the filter element of the present invention. It is an example of use of the filter element of the present invention. It is a perspective view which shows the conventional filter element. Further, it is a diagram showing a mode in which the shape retaining member is mounted in the direction of arrow A. It is a figure which shows the method of manufacturing the conventional filter element. It is a figure which shows the method of manufacturing the conventional filter element, and is a figure which shows the aspect which presses the heating plate 105 to the tape 103, and heat-presses the tape 103 to the end surface 102a of the filter medium 102.

  Hereinafter, preferred embodiments of a filter element and a manufacturing method thereof according to the present invention will be described in detail.

  As illustrated in FIG. 1, the filter element according to the present invention includes a filter element 10 having a pleat-folded filter medium 11 and end plates 12 a and 12 b bonded to end faces of the filter medium 11 that intersect the pleat ridge line 13. The filter medium 11 is made of a first nonwoven fabric having an average fineness of 5 to 30 dtex and a thickness of 1 to 5 mm, which is bonded by the first heat-adhesive fibers, and the end plates 12a and 12b are the second ones. It consists of the 2nd nonwoven fabric with the average fineness of 5-30 dtex and thickness of 1-5 mm adhere | attached by the heat bondable fiber, and the filter medium 11 and the end plates 12a and 12b are 1st heat bondable fiber or / And a second heat-bonding fiber.

  Further, as illustrated in FIG. 1, the filter element manufacturing method of the present invention bonds the end plates 12 a and 12 b to the end face crossing the pleat ridge line 13 of the filter medium 11 with respect to the filter medium 11 that is pleated. The filter element 11 is made of a first non-woven fabric having an average fineness of 5 to 30 dtex and a thickness of 1 to 5 mm, which is bonded by a first heat-bonding fiber. The plates 12a and 12b are made of a second nonwoven fabric having an average fineness of 5 to 30 dtex and a thickness of 1 to 5 mm, which are bonded by the second heat-bonding fibers, and the filter medium 11 and the end plates 12a and 12b. Are bonded by the first heat-bondable fiber or / and the second heat-bondable fiber.

  The filter medium is composed of a first nonwoven fabric having an average fineness of 5 to 30 dtex and a thickness of 1 to 5 mm, which is bonded by a first heat-adhesive fiber. The structure of the first non-woven fabric is not particularly limited as long as it is a non-woven fabric having an average fiber diameter of 5 to 30 dtex and a thickness of 1 to 5 mm, which is bonded by heat-adhesive fibers. For example, the fiber length is 15 to 100 mm. A fiber containing a heat-adhesive fiber, usually called staple fiber, having 5 to 30 crimps / inch is formed on a fiber web using a card machine or an air-lay apparatus, and then the heat-adhesive fiber is used. Nonwoven fabrics obtained by a production method generally called a dry method by bonding constituent fibers by adhesion can be applied. As a method of adhering the constituent fibers with the heat-adhesive fibers, the heat-adhesive fibers can be reduced by using a hot air blowing type dryer or an air-through type dryer on the fiber web containing the heat-adhesive fibers. It is possible to use a method in which a heat treatment is performed by applying a heating airflow that is equal to or higher than the melting point of the melting point component.

  The non-woven fabric obtained by the dry method thus obtained is preferable as the first non-woven fabric because a large number of fibers are oriented in the thickness direction, so that the thickness is large and the thickness is not easily crushed. In addition, since the staple fiber is crimped so that it can be opened by a card machine or the like, it becomes a bulky nonwoven fabric and has excellent repulsive force in the thickness direction against compression. However, a nonwoven fabric using staple fibers is preferable.

  Moreover, the nonwoven fabric formed not only by the dry method but by the manufacturing method of arbitrary nonwoven fabrics, for example by the spun bond method etc. is applicable. In the case of the spunbond method, for example, a core-sheath type heat-adhesive long fiber composed of two types of resin components having different melting points is spun from a nozzle, and then a low-melting-point sheath component is used as an adhesive component. As described above, there is a method in which constituent fibers are bonded together by heat treatment. In addition, when a fiber made of thermoplastic resin is spun from a nozzle into a fiber fleece made of long fiber, a fiber fleece in which the heat-bonded staple fiber is blown and the long fiber and heat-bonded short fiber are integrated. Then, as described above, there is a method in which the constituent fibers are bonded with the heat-bonding fibers by heat treatment. A non-woven fabric using staple fibers is preferable as the first non-woven fabric because a large number of fibers are oriented in the thickness direction, so that the thickness is large and the thickness is difficult to collapse. Moreover, since it is excellent in the repulsive force of the thickness direction also to compression, it is preferable.

  Moreover, in these nonwoven fabric manufacturing methods, it is also possible to use a method in which fibers are entangled with each other by the action of a needle or a water flow to bond the fibers to the formed fiber web, fiber sheet, or fiber fleece. When the fibers are entangled with each other, there is an advantage that the fibers are oriented in the thickness direction, the structure is strengthened, and it is difficult to extend in the surface direction and the thickness is not easily crushed. Moreover, as long as the thickness of a nonwoven fabric is 1-5 mm, it is also possible to use together the method of couple | bonding fibers by heat fusion completely or partially using a heating roll. Moreover, when using a heating roll, it is also possible to increase the thickness of the nonwoven fabric by heating to a predetermined thickness after the thickness is once reduced.

  Although the fiber which comprises a 1st nonwoven fabric needs to contain the 1st heat bondable fiber, as 1st heat bondable fiber, melting | fusing point is lower than another fiber, for example, and another fiber is heat bonded There are fibers consisting of a single resin component that can be made. In addition, there is a composite fiber having a low melting point component on the fiber surface that has a lower melting point than other fibers and can be thermally bonded to the other fibers. A composite fiber composed of a high melting point resin component having a melting point of 10 ° C. or higher, more preferably 50 ° C. or higher, more preferably 100 ° C. or higher, higher than the melting point of the melting point resin component.

  Examples of the form of such a composite fiber include a core-sheath type and a side-by-side type composite fiber having a low-melting-point component on the fiber surface, and the material thereof is, for example, a copolyester / polyester. There are composite fibers made of a combination of fiber-forming polymers such as copolymerized polypropylene / polypropylene, polypropylene / polyamide, polyethylene / polypropylene, polypropylene / polyester, and polyethylene / polyester. Among these fibers, polyester-based fibers that have a relatively high melting point of the high melting point component and are thermally stable, and that have an effect of being excellent in rigidity and shape retention of the entire filter element are preferable. Further, when the low melting point component is a polyester composite fiber, there is an advantage that a large difference in melting point between the high melting point component and the low melting point component can be obtained, and it is easy to bond the filter medium and the end plate. In addition, in order to improve the filtration performance of the filter element, it is also preferable to be a composite fiber made of a polyolefin-based fiber-forming polymer having excellent chargeability.

  In addition to the first heat-bondable fibers, the fibers constituting the first nonwoven fabric are semi-synthetic fibers such as synthetic fibers and rayon, or natural fibers such as cotton and pulp fibers in order to improve the function as a filter element. Can also be included. Synthetic fibers include, for example, polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, polyamide fibers such as nylon 6 and nylon 66, polyolefin fibers such as polypropylene and polyethylene, acrylic fibers such as polyacrylonitrile, and polyvinyl alcohol fibers. And so on. Among these fibers, polyester fibers that have a relatively high melting point and are thermally stable and that provide an excellent effect on the rigidity and shape retention of the entire filter element are preferable. Moreover, in order to improve the filtration performance of the filter element, a polyolefin fiber excellent in chargeability is preferable.

  However, the mixing ratio of fibers other than the first heat-adhesive fiber should be kept in a range that does not prevent the filter medium and the end plate from being thermally bonded, or in a range that does not lose the characteristics as the filter element. Is preferably 30% by mass or less, and more preferably 15% by mass or less. Moreover, the ratio for the whole nonwoven fabric of the 1st heat bondable fiber becomes like this. Preferably it is 100-70 mass%, More preferably, it is 100-80 mass%, More preferably, it is 100-90 mass%. When the ratio of the first heat-adhesive fiber is less than 70% by mass, the bonding force of the filter medium itself due to heat bonding is weak, and the filter element easily collapses due to wind pressure, resulting in a shortened filtration life. There is. In addition, the filter medium and the end plate may not be sufficiently bonded.

  The average fineness of the constituent fibers in the first nonwoven fabric is 5 to 30 dtex, and more preferably 8 to 20 dtex. If it is less than 5 dtex, the nonwoven fabric becomes denser and the filtration efficiency increases, but the pressure loss increases and the dust holding capacity decreases. On the other hand, if it exceeds 30 dtex, the non-woven fabric becomes too coarse, resulting in a problem that the filtration efficiency is lowered and a dust holding capacity is lowered.

  In addition, as a calculation method of the average fineness of a constituent fiber, the fineness of each fiber contained in a constituent fiber is set to a decitex, b decitex, c decitex, etc., and the content ratio of each fiber is a ′ mass%, b ′, respectively. Assuming that the mass%, c ′ mass%,... (A ′ / a) + (b ′ / b) + (c ′ / c)... = (100 / x) The average fineness x can be obtained from the equation.

The thickness of the first nonwoven fabric is 1 to 5 mm, more preferably 1.5 to 4.5 mm, and still more preferably 2 to 4 mm. When the thickness is 1 to 5 mm, there is an advantage that the pressure loss is low and the dust holding capacity is large. If it is less than 1 mm, there arises a problem that the dust holding capacity is lowered. Further, since the contact area with the end plate is small, there is a problem that the filter medium does not sufficiently adhere to the end plate. When the thickness exceeds 5 mm, when the first nonwoven fabric is pleated and used as a filter medium, the wall surfaces of the filter medium come into contact with each other at the ridged or valley portions of the pleat and do not contribute to gas filtration or contribute very little. The portion (hereinafter referred to as dead space) increases, resulting in a problem that pressure loss increases and the dust holding capacity decreases. The thickness is the thickness indicated when a load of ² g per cm ² is applied.

  In the present invention, the dust holding capacity per unit area is increased by making the thickness thicker than the filter element for removing coarse dust as shown in Patent Document 1, and the area of the filter medium is increased by the corresponding amount. Can reduce the total dust holding capacity, and in some cases, the separator 114 made of linear resin as shown in FIG. 4 can be omitted. As a result, the manufacturing cost of the filter medium can be reduced.

Preferably the surface density of the first non-woven fabric is 50 to 400 g / ^{m 2,} more preferably from 75~300g / ^{m 2,} and still more preferably from 90 to 200 g / ^{m 2.} When the surface density is 50 to 400 g / m ² , there is an advantage that the pressure loss is relatively low and the dust holding capacity is large. On the other hand, if it is less than 50 g / m ² , the dust holding capacity may decrease. Moreover, rigidity may become low and the shape retention property of the filter material folded by pleats may fall. Further, the contact area with the end plate is reduced, and the filter medium may not be sufficiently adhered to the end plate. Moreover, when the first nonwoven fabric exceeds 400 g / m ² , when the first nonwoven fabric is pleated and used as a filter medium, the wall surfaces of the filter medium come into contact with each other at the ridged or valley portions of the pleat, resulting in increased dead space. Loss may increase and dust holding capacity may decrease.

  The first nonwoven fabric is laminated with other materials such as nonwoven fabric, woven fabric, knitted fabric, or net for the purpose of reinforcement within a range that does not hinder the adhesion to the end plate and within a range that does not hinder the performance as a filter medium. It is also possible to be a composite non-woven fabric.

  The filtration performance of the first nonwoven fabric preferably functions as a filter for removing coarse dust. Specifically, in the test method defined in ASHRAE 52.1-1992, the mass method is performed using SAE FINE dust. When the test condition is a wind speed of 0.5 m / sec, the particle collection average efficiency is preferably 50 to 99%, the particle collection average efficiency is preferably 60 to 99%, The average collection efficiency is more preferably 70 to 99%. When the particle collection average efficiency is less than 50%, coarse dust removal is insufficient, and when the particle collection average efficiency exceeds 99%, the pore diameter of the nonwoven fabric substrate becomes too fine, so the nonwoven fabric immediately. In some cases, the pressure loss before and after the base material reaches the limit and the life is shortened so that it cannot be used as a filter for removing coarse dust. SAE FINE dust is dust that conforms to the test dust specified in A2 (fine) of ISO12103-1 (1997).

The initial pressure loss of the first nonwoven fabric is preferably 20 Pa or less, more preferably 10 Pa or less, and even more preferably 5 Pa or less when the test condition is a wind speed of 0.1 m / sec. The filtration life of the first nonwoven fabric is preferably 100 g / m ² or more, more preferably 200 g / m ² or more, and 300 g / m ² when the final pressure loss is 200 Pa when the wind speed is 0.5 m / sec. / M ² or more is more preferable. When trying to increase the value of the average particle collection efficiency of the first nonwoven fabric, the filtration life is shortened (the amount of collected dust is reduced), and when trying to increase the life of the filtration (an attempt to increase the amount of collected dust) Then, since the value of the particle collection average efficiency is lowered, the nonwoven fabric within the above preferable range can be more suitably used as a coarse dust removing filter element by performing pleating.

  In order to further improve the filtration performance of the first nonwoven fabric and have filtration performance that can be evaluated not only by the colorimetric method but also by the counting method, a method of electrifying the constituent fibers by subjecting the first nonwoven fabric to electrification is performed. is there. Such electretized fibers are known to lose the electret effect by heating at a relatively high temperature. For this reason, it is preferable that the electrification processing is performed after the first nonwoven fabric is formed by the heat treatment.

  The filtration performance after the first non-woven fabric is charged preferably functions as a filter for removing fine dust. Specifically, in the test method defined in ASHRAE 52.1-1992, SAE FINE is used. When evaluated by a mass method using dust, when the test condition is a wind speed of 0.5 m / sec, the particle collection average efficiency is preferably 50 to 99%, and the particle collection average efficiency is 60 to 99%. It is preferable that the average particle collection efficiency is 70 to 99%. When the particle collection average efficiency is less than 50%, coarse dust removal is insufficient, and when the particle collection average efficiency exceeds 99%, the pore diameter of the nonwoven fabric substrate becomes too fine, so the nonwoven fabric immediately. In some cases, the pressure loss before and after the base material reaches the limit and the life is shortened so that it cannot be used as a filter for removing coarse dust. Further, in the test method defined in JIS B9908 Type 1, when the evaluation is performed by a counting method using atmospheric dust of 0.3 μm, the particle collection average efficiency is 5 to 5 when the test condition is a wind speed of 0.1 m / sec. It is preferably 50%, the particle collection average efficiency is preferably 10 to 50%, and the particle collection average efficiency is more preferably 20 to 50%.

  In the filter element of the present invention, as illustrated in FIG. 1, the first nonwoven fabric 11 is pleated and the end plate 12 a is bonded to the end face that intersects the pleat ridge line 13 of the filter medium 11. In addition, in FIG. 1, the aspect which the end plate 12b adhere | attaches in the direction of arrow A to the end surface which cross | intersects the pleated ridgeline of the 1st nonwoven fabric 11 folded by pleats is also illustrated. The form of pleat folding of the first nonwoven fabric is not particularly limited as long as it is folded into a zigzag shape, and the pleat folding method is a method using a pleating machine such as a reciprocating type or a rotary type, or a zigzag shape. There is a method of pressing with a pressed die.

  The filter medium 10 is formed with a large number of pleats as exemplified in FIGS. 1 and 2. Specifically, the height H of the pleats is preferably 10 to 100 mm, more preferably 15 to 75 mm, and more preferably 20 to 20 mm. 50 mm is more preferable. The pitch P of the pleats is preferably 8 to 50 mm, more preferably 10 to 40 mm, and still more preferably 12 to 30 mm. Moreover, it is preferable that ratio P / H of pitch P (mm) and height H (mm) is 0.2-2, it is preferable that it is 0.3-1.5, 0.4-1 More preferably. If P / H is less than 0.2, the pleat angle becomes too small, and the pleat angle is widened by the wind pressure and adheres to the adjacent pleats, resulting in dead space and reducing the dust holding capacity. is there. Moreover, when P / H exceeds 2, the number of pleats decreases, the area of the whole filter medium decreases, and the dust holding capacity may decrease. Moreover, when the height of the pleat is less than 10 mm, the area of the entire filter medium is reduced, and the dust holding capacity may be reduced. If the height of the pleats exceeds 100 mm, the area of the entire filter medium increases, but the angle of the pleats becomes too small, resulting in a dead space, which may reduce the dust holding capacity.

As shown in FIG. 2, when the pitch of the pleats is P (mm) and the thickness of the first nonwoven fabric is T (mm),
Formula: a = (1-2T / P) × 100
The aperture ratio a calculated from the above is preferably 50 to 90%, more preferably 55 to 85%, and still more preferably 60 to 80%. As apparent from FIG. 2, when the value of the ratio P / H between the pitch P (mm) and the height H (mm) of the pleats is small, the thickness is about twice the thickness T (mm) of the first nonwoven fabric. The width of the corresponding length is substantially equal to the dead space width D (mm). Therefore, as the number of pleats of the filter element increases and the thickness of the first nonwoven fabric increases, the dead space increases, the processing air volume as the filter element decreases, and the filtration life tends to decrease. On the other hand, as the number of ridges of the filter element increases and the thickness of the first nonwoven fabric increases, the filtration area of the first nonwoven fabric increases and the filtration life tends to increase. Therefore, the above equation can be said to be an equation representing the most preferable state in which both of these tendencies are balanced and the filtration life is long. Therefore, if the aperture ratio a is less than 50%, the initial pressure loss of the filter element is greatly increased, the filtration life is shortened, and the dust holding capacity may be decreased. Moreover, when the opening ratio a exceeds 90%, the filtration area of the first nonwoven fabric is reduced, the filtration life of the air filter unit is shortened, and the dust holding capacity may be reduced. In the case where the first nonwoven fabric is a composite nonwoven fabric laminated with another material such as a nonwoven fabric, a woven fabric, a knitted fabric, or a net, in the above formula for obtaining the aperture ratio a, the thickness T ( mm), the thickness of the composite nonwoven fabric can be used.

  The end plate is composed of a second nonwoven fabric having an average fineness of 5 to 30 dtex and a thickness of 1 to 5 mm, which is bonded by a second heat-bonding fiber. The structure of the second non-woven fabric is not particularly limited as long as it is a non-woven fabric having an average fiber diameter of 5 to 30 dtex and a thickness of 1 to 5 mm, which is bonded by a heat-adhesive fiber. For example, the fiber length is 15 to 100 mm. A fiber containing a heat-adhesive fiber, usually called staple fiber, having 5 to 30 crimps / inch is formed on a fiber web using a card machine or an air-lay apparatus, and then the heat-adhesive fiber is used. Nonwoven fabrics obtained by a production method generally called a dry method by bonding constituent fibers by adhesion can be applied. As a method of adhering the constituent fibers with the heat-adhesive fibers, the heat-adhesive fibers can be reduced by using a hot air blowing type dryer or an air-through type dryer on the fiber web containing the heat-adhesive fibers. It is possible to use a method in which a heat treatment is performed by applying a heating airflow that is equal to or higher than the melting point of the melting point component.

  The nonwoven fabric obtained by the dry method thus obtained has a large number of fibers oriented in the thickness direction, so that it has a large thickness and excellent adhesion to the filter frame containing the filter element, and the thickness is not easily crushed. Therefore, it is preferable as the second nonwoven fabric. In addition, since the staple fiber is crimped so that it can be opened by a card machine or the like, it becomes a bulky nonwoven fabric and has excellent repulsive force in the thickness direction against compression. However, a nonwoven fabric using staple fibers is preferable.

  Moreover, the nonwoven fabric formed not only by the dry method but by the manufacturing method of arbitrary nonwoven fabrics, for example by the spun bond method etc. is applicable. In the case of the spunbond method, for example, a core-sheath type heat-adhesive long fiber composed of two types of resin components having different melting points is spun from a nozzle, and then a low-melting-point sheath component is used as an adhesive component. As described above, there is a method in which constituent fibers are bonded together by heat treatment. In addition, when a fiber made of thermoplastic resin is spun from a nozzle into a fiber fleece made of long fiber, a fiber fleece in which the heat-bonded staple fiber is blown and the long fiber and heat-bonded short fiber are integrated. Then, as described above, there is a method in which the constituent fibers are bonded with the heat-bonding fibers by heat treatment. A non-woven fabric using staple fibers is preferable as the second non-woven fabric because a large number of fibers are oriented in the thickness direction, so that the thickness is large and the thickness is difficult to collapse. Moreover, since it is excellent in the repulsive force of the thickness direction also to compression, it is preferable.

  Moreover, in these nonwoven fabric manufacturing methods, it is also possible to use a method in which fibers are entangled with each other by the action of a needle or a water flow to bond the fibers to the formed fiber web, fiber sheet, or fiber fleece. When the fibers are entangled with each other, there is an advantage that the fibers are oriented in the thickness direction, the structure is strengthened, and it is difficult to extend in the surface direction and the thickness is not easily crushed. Moreover, as long as the thickness of a nonwoven fabric is 1-5 mm, it is also possible to use together the method of couple | bonding fibers by heat fusion completely or partially using a heating roll. Moreover, when using a heating roll, it is also possible to increase the thickness of the nonwoven fabric by heating to a predetermined thickness after the thickness is once reduced.

  Although the fiber which comprises a 2nd nonwoven fabric needs to contain a 2nd heat bondable fiber, as a 2nd heat bond fiber, melting | fusing point is lower than another fiber, for example, and another fiber is heat bonded There are fibers consisting of a single resin component that can be made. In addition, there is a composite fiber having a low melting point component on the fiber surface that has a lower melting point than other fibers and can be thermally bonded to the other fibers. A composite fiber composed of a high melting point resin component having a melting point of 10 ° C. or higher, more preferably 50 ° C. or higher, more preferably 100 ° C. or higher, higher than the melting point of the melting point resin component.

  Examples of the form of such a composite fiber include a core-sheath type and a side-by-side type composite fiber having a low-melting-point component on the fiber surface, and the material thereof is, for example, a copolyester / polyester. There are composite fibers made of a combination of fiber-forming polymers such as copolymerized polypropylene / polypropylene, polypropylene / polyamide, polyethylene / polypropylene, polypropylene / polyester, and polyethylene / polyester. Among these fibers, polyester-based fibers that have a relatively high melting point of the high melting point component and are thermally stable, and that have an effect of being excellent in rigidity and shape retention of the entire filter element are preferable. Further, when the low melting point component is a polyester composite fiber, there is an advantage that a large difference in melting point between the high melting point component and the low melting point component can be obtained, and it is easy to bond the filter medium and the end plate.

  In addition to the second heat-adhesive fiber, the fibers constituting the second nonwoven fabric are semi-synthetic fibers such as synthetic fibers and rayon, or natural fibers such as cotton and pulp fibers, in order to improve the function as a filter element. Can also be included. Synthetic fibers include, for example, polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, polyamide fibers such as nylon 6 and nylon 66, polyolefin fibers such as polypropylene and polyethylene, acrylic fibers such as polyacrylonitrile, and polyvinyl alcohol fibers. And so on. Among these fibers, polyester fibers that have a relatively high melting point and are thermally stable and that provide an excellent effect on the rigidity and shape retention of the entire filter element are preferable.

  However, the mixing ratio of fibers other than the second heat-adhesive fiber should be kept in a range that does not prevent the filter medium and the end plate from being thermally bonded, or in a range that does not lose the characteristics as the filter element. Is preferably 30% by mass or less, and more preferably 15% by mass or less. The proportion of the second heat-adhesive fiber in the entire nonwoven fabric is preferably 100 to 70% by mass, more preferably 100 to 80% by mass, and still more preferably 100 to 90% by mass. When the ratio of the second heat-adhesive fiber is less than 70% by mass, the bonding force of the end plate itself due to heat adhesion is weak, and the pleated shape of the filter element may not be maintained firmly. In addition, the filter medium and the end plate may not be sufficiently bonded.

  The average fineness of the constituent fibers in the second nonwoven fabric is 5 to 30 dtex, and more preferably 8 to 20 dtex. If it is less than 5 decitex, the non-woven fabric has a dense mesh, and may not adhere sufficiently to the coarse filter medium. In addition, since the fineness is small, the end plate becomes too flexible, and the pleated shape of the filter element may not be maintained firmly. On the other hand, if it exceeds 30 dtex, the texture of the nonwoven fabric becomes too coarse, so that the end plate becomes too flexible, and the pleated shape of the filter element may not be maintained firmly.

  The thickness of the second nonwoven fabric is 1 to 5 mm, more preferably 1.5 to 4.5 mm, and still more preferably 2 to 4 mm. A thickness of 1 to 5 mm is preferable because the cushioning property is excellent when the filter element is attached to the filter frame, and the sealing property between the filter frame is excellent. On the other hand, if it is less than 1 mm, the end plate becomes too flexible, and the pleated shape of the filter element may not be maintained firmly. Further, the sealing performance with the filter frame that houses the filter element may be poor. Moreover, when it exceeds 5 mm, the filtration area as a filter element will decrease, As a result, a pressure loss will become high and dust holding capacity may fall.

Preferably the surface density of the second non-woven fabric is 50 to 400 g / ^{m 2,} more preferably from 75~300g / ^{m 2,} and still more preferably from 90 to 200 g / ^{m 2.} When the surface density is 50 to 400 g / m ² , the pleat shape is firmly maintained and the sealing performance with the filter frame that houses the filter element is excellent. On the other hand, if it is less than 50 g / m ² , the end plate becomes too flexible, and the pleated shape of the filter element may not be maintained firmly. Further, the sealing performance with the filter frame that houses the filter element may be poor. In addition, the filter medium may not sufficiently adhere to the end plate. Moreover, when it exceeds 400 g / m < ² >, the filtration area as a filter element will decrease, As a result, a pressure loss will become high and dust holding capacity may fall.

  The second nonwoven fabric may be a composite nonwoven fabric laminated with another material such as a nonwoven fabric, a woven fabric, a knitted fabric, or a net for the purpose of reinforcement within a range that does not hinder adhesion with the filter medium. . In this case, the filter medium is bonded to the second nonwoven fabric side, and the other material side is arranged to be the filter frame side. Other materials can be made of breathable materials, and the bonding method can be improved by using hot-melt non-woven fabric or adopting processing methods that maintain breathability, such as impregnation, spraying, surface coating, and dot processing. It is also possible to give the plate air permeability and use the end plate as the second nonwoven fabric as will be described later.

  The value of the bending resistance (Gurley method) serving as an index of the flexibility of the second nonwoven fabric or the end plate is preferably 1 mN or more, more preferably 2 mN or more, and further preferably 4 mN or more. In addition, bending resistance uses the value measured according to bending resilience A method bending resistance (Gurley method) described in JIS L1096: 2010, and shall use the average value of a length direction and a horizontal direction.

  In addition, as illustrated in FIGS. 1 and 2, the size of the end plate is set to be the same as or slightly larger than the pleat height H (mm) and the pleat width W (mm). It is preferable to do.

  The filtration performance of the second nonwoven fabric can function as a second filter medium for removing coarse dust. In this case, in the test method specified in ASHRAE 52.-1992, using SAE FINE dust When evaluated by a mass method, when the test condition is a wind speed of 0.5 m / sec, the particle collection average efficiency is preferably 50 to 99%, and the particle collection average efficiency is preferably 60 to 99%. The average particle collection efficiency is more preferably 70 to 99%. When the particle collection average efficiency is less than 50%, coarse dust removal is insufficient, and when the particle collection average efficiency exceeds 99%, the pore diameter of the nonwoven fabric substrate becomes too fine, so the nonwoven fabric immediately. In some cases, the pressure loss before and after the base material reaches the limit and the life is shortened so that it cannot be used as a filter medium for removing coarse dust.

In order to function as the second filter medium for removing coarse dust, the initial pressure loss of the second nonwoven fabric is preferably 20 Pa or less, more preferably 10 Pa or less, when the test condition is a wind speed of 0.1 m / sec. 5 Pa or less is more preferable. The filtration life of the second nonwoven fabric is preferably 100 g / m ² or more, more preferably 200 g / m ² or more, and 300 g / m ² when the final pressure loss is 200 Pa when the wind speed is 0.5 m / sec. / M ² or more is more preferable. In addition, if it tries to raise the value of the particle collection average efficiency of the second nonwoven fabric, the filtration life will be shortened (the amount of collected dust will be reduced), and if it is attempted to increase the life of the filtration (an attempt to increase the amount of collected dust) Then, since the value of particle collection average efficiency will fall, if it is a nonwoven fabric of the said preferable range, it can use more suitably as a filter element for coarse dust removal.

  In the present invention, the configuration of the second nonwoven fabric may be different from the first nonwoven fabric or the same configuration. As a result of selecting the optimal configuration as the filter medium and selecting the optimal configuration as the end plate, the configuration of the second nonwoven fabric is often different from the configuration of the first nonwoven fabric, but by being the same configuration It is possible to manufacture both the filter medium and the end plate with a single type of non-woven fabric, and there is a cost reduction effect. In addition, as described later, there is an effect that the end plate is easily adhered to the end face of the filter medium. Therefore, when the performance as an end plate is important, the configuration of the second nonwoven fabric can be different from the configuration of the first nonwoven fabric, and when the performance is not so important, the configuration of the second nonwoven fabric is the first. It is preferable to set it as the same structure as 1 nonwoven fabric. Moreover, when using an end plate as a 2nd filter medium so that it may mention later, it is preferable to make the structure of an end plate the same as the structure of the 1st nonwoven fabric which has a suitable structure as a filter medium, or approximate.

  In the present invention, the end plate is bonded to the end face that intersects the pleated filter medium and the ridge line of the filter medium. Crossing here means that the ridgeline and the end face intersect at an arbitrary angle, and it does not necessarily mean that it intersects at right angles, but usually it is at right angles or near right angles except for special shapes. Filter elements that intersect at an angle are required.

  Moreover, the said filter medium and the said end plate are adhere | attached with the 1st heat bondable fiber or / and the 2nd heat bondable fiber. Specifically, the filter medium and the end plate are fixed in contact with each other, the melting point P1 of the low melting point resin component of the first heat-adhesive fiber contained in the filter medium and the second heat bond contained in the end plate. The low melting point resin component (P2 or P1) having a higher melting point than the melting point of the low melting point resin component (P1 or P2) having a lower melting point compared with the melting point P2 of the low melting point resin component of the conductive fiber The heat-adhesive fiber (the first heat-adhesive fiber or the second heat-adhesive fiber) contained in the filter medium or the end plate is obtained by heat-treating the filter medium or the end plate below the temperature of the melting point of Adhesion is performed by fusing to the constituent fiber of the other side (end plate or filter medium). In addition, when heat processing are performed more than the higher melting | fusing point of melting | fusing point P1 and melting | fusing point P2, both heat bondable fibers (1st heat bondable fiber and 2nd heat bondable fiber) Adhesion is performed by fusing to the constituent fibers of the other side (end plate and filter medium).

  As a preferable form of adhesion, for example, if the first heat-adhesive fiber and the second heat-adhesive fiber are fibers of the same material, the heat-adhesive fibers are compatible with each other, so the filter medium and the end plate are There is an advantage that it is easy to adhere. Further, even when the melting point P1 of the first heat-adhesive fiber and the melting point P2 of the second heat-adhesive fiber are the same, the filter medium and the end plate can be easily bonded because the bonding temperature can be made constant. There are advantages. Therefore, if the first heat-adhesive fiber and the second heat-adhesive fiber are the same fiber, the heat-adhesive fibers are compatible with each other and the bonding temperature can be made constant. Has the advantage that it is easier to bond. Further, if the first nonwoven fabric and the second nonwoven fabric have the same fiber configuration, the adhesive behavior of the first heat-adhesive fiber and the second heat-adhesive fiber due to heating to the other fibers is the same. There is an advantage that the end plate and the end plate are more easily bonded.

  In the present invention, since the filter medium and the end plate are bonded to each other by the heat-bonding fibers contained therein, the weight is reduced compared to the method using an adhesive such as the filter element for removing coarse dust shown in Patent Document 1. The cost can be reduced. Further, by matching or approximating the configuration of the end plate to the configuration of the filter medium, the filter medium and the end plate can be easily bonded. Moreover, since the thickness of the end plate is increased, the shape retention of the pleated filter medium is excellent.

  As a method for adhering the filter medium and the end plate, for example, a method described in Patent Document 2 can be applied. In FIGS. 5 and 6 of the document, an end surface 102a perpendicular to the pleat ridge line is attached to the fixing side of a filter medium 102 that has been pleated in a U-shaped mold 106 having a rectangular box shape. Next, a tape 103 having an adhesive layer is superimposed on the end face 102a of the filter medium 102, and in this state, the heating plate 105 is pressed against the tape 103 and the tape 103 is thermocompression bonded to the end face 102a of the filter medium 102. Is described. In this invention, a filter medium and an end plate can be adhere | attached by using the end plates 12a and 12b instead of the tape 103 which has an contact bonding layer.

  When the method shown in FIG. 6 is adopted, in the present invention, the heating plate 105 is directly pressed against the end plates 12a and 12b. A part of the low melting point resin component of the second heat-adhesive fiber constituting the plate may be melted and adhered. Therefore, the end plate is set as a composite nonwoven fabric obtained by laminating the second nonwoven fabric and another material having a melting point higher than the low melting point resin component, such as a nonwoven fabric, a woven fabric, a knitted fabric, or a net, on the second nonwoven fabric side. If the filter medium is disposed and the heating plate is disposed on the other material side, the low melting point resin component can be prevented from adhering to the heating plate 105.

  In the present invention, the filter medium and the end plate are bonded to each other by the first thermal adhesive fiber or / and the second adhesive fiber to once form a filter element, and the filter element is used as a filter element intermediate, It is also preferable to heat-treat the entire filter element intermediate at a temperature higher than the melting point of the first heat-adhesive fiber or the second adhesive fiber, for example, 10 ° C. or higher. By heating the entire filter element intermediate, the entire filter element can be changed to a more rigid structure. The reason for this is that the thickness of the first nonwoven fabric that has been compressed during the pleat folding process is restored to the original thickness, and in this state, re-fusion with the first heat-bonding fibers is performed and the thickness is restored. This is considered to be because the V-shaped or U-shaped shape is fixed as it is because the pleat is fixed as it is, and the pleated peak portion or valley portion is re-fused in the recovered state.

  In the present invention, it is essential that the end plate is bonded to the end face that intersects the pleated ridge line of the pleated filter medium, but the second end plate is also attached to the end face parallel to the pleated ridge line of the filter medium. Can be glued. The material of the second end plate is not particularly limited, and the method of adhering to the filter medium is not particularly limited, and can be the same end plate as the end plates 12a and 12b. .

  The overall size of the filter element is such that the dimension of one side of the air inflow surface is 80 to 500 mm in the case of a filter element that is used by being mounted on an air conditioner in a living environment such as an automobile or a home air cleaner. Is preferable, 100 to 400 mm is more preferable, and 150 to 300 mm is still more preferable. Further, the depth is preferably 10 to 100 mm, more preferably 15 to 75 mm, and still more preferably 20 to 50 mm. In addition, in the case of filter elements used as coarse dust removal filters such as package filters, fan coil units, and central air conditioning filter units in air purifiers installed in buildings, factories, offices, etc., the air inflow surface The dimension of one side is preferably 200 to 1500 mm, more preferably 300 to 1000 mm, and still more preferably 400 to 700 mm. The depth is preferably 10 to 500 mm, more preferably 15 to 400 mm, and still more preferably 20 to 300 mm.

  When the filter element is applied to an air conditioner, the filter element can be used by being attached to a filter frame. The filter frame is not particularly limited as long as it is a rigid material, and wood, metal, plastic, or the like is applied, and wood is preferable when incinerated and discarded after several washing and regeneration.

  In the filter element of the present invention, the second nonwoven fabric constituting the end plate can be made of the same material as the first nonwoven fabric constituting the filter medium or a similar material. If the filter medium is 1, the end plate can be used as the second filter medium. As a preferred example of using the end plate as the second filter medium, the automobile air conditioner 20 of FIG. 3 can be exemplified.

  In the air conditioner 20, the filter element 10 of the present invention is housed in the filter frame 30. The filter frame 30 is provided between the inflow port 31 through which the inside air flows in, the inflow port 32 through which the outside air flows in, the outflow port 34 through which the airflow after filtration flows out, and the inflow ports 31, 32 and the outflow port 34. And an opening 33 a is provided in a part of the side wall 33. Further, the filter element 10 is accommodated so that at least a part of the opening 33a on the side wall is closed by the end plate 12a or 12b, and filtration is possible by the end plate 12a or 12b. A duct 41 for inside air is connected to the opening 33a, and an outflow duct 42 is connected to the outlet 34. The filter frame 33 is provided with an inside / outside air switching door 35 that switches between inside and outside air at the boundary between the inlets 31 and 32, and a blower 40 is provided below the storage portion of the filter element 10. A motor 50 for driving the motor 40 is disposed outside the filter frame 33.

  Even when the filter element 10 is clogged by this filter device 20, the inside air flows into the filter element 10 from the duct 41 for inside air through the opening 33a and the end plates 12a and 12b as a bypass, and the inside air is filtered by the end plate. be able to. Further, since the air passing through the end plates 12a and 12b is only the inside air having a very low dust concentration, the pressure loss of the end plates 12a and 12b is difficult to increase. As a result, it is possible to avoid the risk that the blower 40 is suddenly burdened or the air flow rate is extremely reduced, and it is possible to secure time until the filter element is replaced.

  The filtration performance of the filter element of the present invention preferably functions as a filter for removing coarse dust. When only the first nonwoven fabric is used as a filter medium, the SAE is used in the test method defined in ASHRAE 52.1-1992. When evaluated by a mass method using FINE dust, when the dimension of at least one side of the air inflow surface is 80 to 500 mm, the average particle collection efficiency is 50 to 99 when the test condition is the frontage wind speed of 2.7 m / sec. %, The particle collection average efficiency is preferably 60 to 99%, and the particle collection average efficiency is more preferably 70 to 99%. When the particle collection average efficiency is less than 50%, coarse dust removal is insufficient, and when the particle collection average efficiency exceeds 99%, the pore diameter of the nonwoven fabric substrate becomes too fine, so the nonwoven fabric immediately. In some cases, the pressure loss before and after the base material reaches the limit and the life is shortened so that it cannot be used as a filter for removing coarse dust.

The initial pressure loss of the filter element is preferably 150 Pa or less and more preferably 100 Pa or less when the test condition is a frontage wind speed of 2.7 m / sec when the dimension of at least one side of the air inflow surface is 80 to 500 mm. 80 Pa or less is more preferable. The filter element has a filtration life of preferably 500 g / m ² or more, more preferably 750 g / m ² or more, more preferably 1000 g / m ² or more when the final pressure loss is 200 Pa. Further preferred. When the nonwoven fabric substrate is a composite substrate laminated with other materials such as nonwoven fabric, woven fabric, knitted fabric, or net, the above-mentioned pressure loss is the pressure of other laminated materials or filters. It can be set as the pressure loss which added loss.

  As described above, the filter element of the present invention increases the dust holding capacity per unit area by increasing the thickness of the filter medium as compared with the filter element for removing coarse dust as disclosed in Patent Document 1. By increasing the pleat interval accordingly and reducing the area of the filter medium, the entire dust holding capacity can be made equal, and as a result, the manufacturing cost of the filter element can be reduced. Further, since the filter medium and the end plate are bonded to each other by the heat-bonding fibers contained therein, the weight can be reduced as compared with the method using an adhesive such as the filter element for removing coarse dust shown in Patent Document 1. And cost reduction is possible. Further, by matching or approximating the configuration of the end plate to the configuration of the filter medium, the filter medium and the end plate can be easily bonded. Moreover, since the thickness of the end plate is increased, the shape retention of the pleated filter medium is excellent. In addition, when a structure in which air passes through the end plate and the end plate is used as the second filter medium, a lower pressure loss and a longer life can be achieved. Thus, the filter element for removing coarse dust of the present invention has a novel structure that is excellent in filtration life or dust holding capacity, has little pressure loss, and can be reduced in weight and cost.

  Examples of the present invention will be described below, but these are only suitable examples for facilitating the understanding of the present invention, and the present invention is not limited to the contents of these examples.

(First nonwoven fabric or second nonwoven fabric filtration performance test method-mass method)
In the test method defined in ASHRAE 52.1-1992, after supplying SAE FINE dust at a wind speed of 0.5 m / sec until the pressure loss reaches 200 Pa, the particle collection average efficiency (%) and the filtration life ( Dust collection amount (g / m ² ) is determined. The initial pressure loss (Pa) is a value measured at a wind speed of 0.1 m / sec.

(Filter element filtration performance test method-mass method)
In the test method specified in ASHRAE 52.1-1992, after the SAE FINE dust was supplied at a frontage wind speed of 2.7 m / sec until the pressure loss reached 200 Pa, the particle collection average efficiency per frontage (%) And the filtration life (dust collection amount) (g / m ² ) is determined. The initial pressure loss (Pa) is a value measured at a frontage wind speed of 2.7 m / sec.
In addition, the filtration performance of a filter element shows the evaluation at the time of using only a 1st nonwoven fabric as a filter medium.

Example 1
65% by mass staple fiber composed of a composite fiber (fineness 22 decitex, fiber length 64 mm) composed of a polyester resin having a melting point of 248 ° C. and a sheath component having a melting point of 72 ° C., and a core component having a melting point of 248 ° C. It is a polyester resin, mixed with 35% by mass of staple fibers made of a composite fiber (fineness 6.6 dtex, fiber length 51 mm) made of polyester resin with a sheath component having a melting point of 72 ° C., and a fiber web using a card machine. (Average fineness 12.1 dtex) was formed. Next, this fiber web was subjected to heat bonding treatment with hot air at 150 ° C. using an air-through dryer to form a first nonwoven fabric having a surface density of 95 g / m ² and a thickness of 1.5 mm. Table 1 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric.
Next, the obtained first nonwoven fabric was subjected to pleating so that the height of the pleats was 29 mm, the pitch (peak interval) of the pleats was 20 mm, and several tens of pleats were used, thereby obtaining a filter medium. Next, an end plate (flexural softness 4.9 mN) produced by cutting the first nonwoven fabric into a width of 29 mm and a length of 206 mm is bonded to the end face of the filter medium intersecting with the pleat ridgeline by heating. A filter element having a length of 206 mm on the end plate side and 212 mm on the side perpendicular to the end plate was produced. Table 1 shows the results of evaluating the filtration performance of the obtained filter element.
As shown in FIGS. 5 and 6, the end plate is bonded to the end face perpendicular to the pleated ridge line of the filter material obtained by folding the pleat in a rectangular box-shaped mold 106. Then, the end plate was placed on the end face of the filter medium, and in this state, the heating plate 105 at 100 ° C. was pressed against the end plate, and the end plate was thermocompression bonded to the end face of the filter medium.

(Example 2)
A filter element was produced in the same manner as in Example 1, except that a first nonwoven fabric having a surface density of 125 g / m ² and a thickness of 2.2 mm was formed. Table 1 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric and the filtration performance of the obtained filter element.

(Example 3)
A filter element was produced in the same manner as in Example 1, except that a first nonwoven fabric having a surface density of 140 g / m ² and a thickness of 2.8 mm was formed. Table 1 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric and the filtration performance of the obtained filter element.

Example 4
A filter element was produced in the same manner as in Example 1 except that a first nonwoven fabric having a surface density of 150 g / m ² and a thickness of 3.5 mm was formed. Table 1 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric and the filtration performance of the obtained filter element.

(Example 5)
A filter element was produced in the same manner as in Example 1 except that a first nonwoven fabric having a surface density of 190 g / m ² and a thickness of 4.5 mm was formed. Table 2 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric and the filtration performance of the obtained filter element.

(Example 6)
In Example 1, a first nonwoven fabric having a surface density of 140 g / m ² and a thickness of 2.8 mm was formed, and in the same manner as the first nonwoven fabric, a surface density of 125 g / m ² and a thickness of 2.2 mm. A filter element was produced in the same manner as in Example 1 except that the second nonwoven fabric was formed. Table 2 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric and the second nonwoven fabric and the filtration performance of the obtained filter element.

(Example 7)
In Example 1, the first nonwoven fabric having a surface density of 150 g / m ² and a thickness of 3.5 mm was formed. Similarly to the first nonwoven fabric, the surface density was 140 g / m ² and the thickness was 2.8 mm. The second nonwoven fabric was formed, and the first nonwoven fabric was subjected to pleating so that the height of the pleats was 29 mm, the pitch of the pleats (peak interval) was 27 mm, and the number of pleats was 8 peaks. A filter element was produced in the same manner as in Example 1 except for the above. Table 2 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric and the second nonwoven fabric and the filtration performance of the obtained filter element.

(Example 8)
In Example 1, the first nonwoven fabric having a surface density of 150 g / m ² and a thickness of 3.5 mm was formed. Similarly to the first nonwoven fabric, the surface density was 140 g / m ² and the thickness was 2.8 mm. The second nonwoven fabric was formed, and the first nonwoven fabric was subjected to pleating so that the height of the pleats was 29 mm, the pleat pitch (peak interval) was 14 mm, and the number of pleats was 15 peaks. A filter element was produced in the same manner as in Example 1 except for the above. Table 2 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric and the second nonwoven fabric and the filtration performance of the obtained filter element.

(Comparative Example 1)
The core component is a polypropylene resin having a melting point of 160 ° C., the sheath component is 75% by mass of staple fibers made of a polyethylene resin having a melting point of 140 ° C. (fineness: 6.6 dtex, fiber length: 64 mm), and the core component has a melting point of 160 A card machine is used by mixing 25% by mass of staple fibers made of a composite fiber (fineness 2.2 decitex, fiber length 51 mm), which is a polypropylene resin having a melting point of 140 ° C. and a sheath component. A fiber web (average fineness 4.4 dtex) was formed. Next, this fiber web was subjected to heat adhesion treatment with hot air at 140 ° C. using an air-through dryer to form a first nonwoven fabric having a surface density of 85 g / m ² and a thickness of 0.9 mm. Table 3 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric.
Next, the obtained first nonwoven fabric was subjected to pleating so that the height of the pleats was 29 mm, the pitch (peak interval) of the pleats was 5 mm, and the number of pleats was several 40. Thus, a filter medium was obtained. Then, an end plate fabricated by cutting to width 29 mm × length 206mm after coating the spot shape heat crimped surface density 220 g / ^{m 2} spunbond nonwoven fabric surface density 380 g / ^{m 2} of a hot melt resin (Tsuyoshi Softness: too high to be measured, filtration performance: impossible to measure due to lack of air permeability), and this end plate is bonded to the end face of the filter medium intersecting the pleated ridge line by heating in the same manner as in Example 1. Thus, a filter element having an overall size of 206 mm on the end plate side and 212 mm on the side perpendicular to the end plate was produced. Table 3 shows the results of evaluating the filtration performance of the obtained filter element. In Comparative Example 1, since the end plate was coated with hot melt resin, and the area of the filter medium was large, there was a problem that the manufacturing cost was high. Moreover, since the average fineness was less than 5 dtex, the mass life efficiency was high compared with Examples 1-7, but the filtration life was short.

(Comparative Example 2)
In Example 1, an attempt was made to produce a filter element in the same manner as in Example 1 except that a first nonwoven fabric having a surface density of 50 g / m ² and a thickness of 0.7 mm was formed. Since the thickness of the first nonwoven fabric used for the end plate was also thin, it was difficult to bond the filter medium to the end plate, and the filter element could not be manufactured. Table 3 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric.

(Comparative Example 3)
In Example 1, an attempt was made to manufacture a filter element in the same manner as in Example 1 except that a first nonwoven fabric having a surface density of 80 g / m ² and a thickness of 0.8 mm was formed. Since the thickness of the first nonwoven fabric used for the end plate was also thin, it was difficult to bond the filter medium to the end plate, and the filter element could not be manufactured. Table 3 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric.

(Comparative Example 4)
A filter element was produced in the same manner as in Example 1 except that a first nonwoven fabric having a surface density of 280 g / m ² and a thickness of 6.0 mm was formed. Table 3 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric and the filtration performance of the obtained filter element. In Comparative Example 4, since the thickness of the first non-woven fabric is thick, the wall surfaces of the filter medium are in contact with each other at the pleated or valley portions of the pleats, and the dead space increases. As a result, the obtained filter element is filtered. It was inferior in life.

(Comparative Example 5)
In Example 1, the first nonwoven fabric having a surface density of 450 g / m ² and a thickness of 10.0 mm was formed. Similarly to the first nonwoven fabric, the surface density was 140 g / m ² and the thickness was 2.8 mm. The second nonwoven fabric was formed, and the first nonwoven fabric was subjected to pleating so that the height of the pleats was 29 mm, the pleat pitch (peak interval) was 40 mm, and the number of the pleats was 5 peaks, and a filter medium was obtained. A filter element was produced in the same manner as in Example 1 except for the above. Table 3 shows the results of evaluating the filtration performance of the obtained first nonwoven fabric and the second nonwoven fabric and the filtration performance of the obtained filter element. In this comparative example 5, because the thickness of the first nonwoven fabric is thick, the wall surfaces of the filter media are in contact with each other at the pleated or valley portions of the pleats, and the dead space increases. As a result, the obtained filter element is The initial pressure loss was high and it was not worthy of evaluating the filtration performance.

Table 1

Table 2

Table 3

  As is clear from Tables 1 to 3, the filter elements of Examples 1 to 8 have a structure in which the filtration life is excellent, the pressure loss is small, and the weight and cost can be reduced. It was suitable as a filter element for removal. The end plate could be used as the second filter medium. On the other hand, in Comparative Example 1, since the hot melt resin was coated on the end plate and the area of the filter medium was large, there was a problem that the manufacturing cost was high. Moreover, since the average fineness was less than 5 dtex, the mass life was high, but the filtration life was short. In Comparative Examples 2 to 3, it is difficult to form a filter element. In addition, the filter elements of Comparative Examples 4 to 5 have high pressure loss, poor filtration life, and are not suitable as filter elements for removing coarse dust. It was.

DESCRIPTION OF SYMBOLS 10 Filter element 11 Filter medium 12a End plate 12b End plate 13 Pleated peak 20 Air conditioner 30 Filter frame 31 Inner air flow inlet 32 Outer air flow inlet 33 Side wall 33a Opening 34 Outlet 35 Inside / outside air switching door 40 Blower 41 Inside air duct 42 Outflow Duct 50 Motor 102 Filter medium 102a End face 103 Tape 105 Heating plate 106 U-shaped mold section 110 Filter element 111 Non-woven fabric base material 112a, 112b Shape retaining member 113 Pleated processing 114 Separator

Claims (2)

A filter element having a filter medium folded in pleats and an end plate bonded to an end face intersecting a pleat line of the filter medium,
The filter medium is made of a first non-woven fabric having an average fineness of 5 to 30 dtex and a thickness of 1 to 5 mm, which is bonded by a first heat-bonding fiber, and the end plate is bonded by a second heat-bonding fiber. Made of a second non-woven fabric having an average fineness of 5 to 30 dtex and a thickness of 1 to 5 mm, and the filter medium and the end plate are made of the first heat-adhesive fiber and / or the second adhesive fiber. A filter element characterized by being bonded. A filter element manufacturing method for adhering an end plate to an end surface intersecting a ridge line of the pleat of the filter medium with respect to a pleated folded filter medium,
The filter medium is made of a first non-woven fabric having an average fineness of 5 to 30 dtex and a thickness of 1 to 5 mm, which is bonded by a first heat-bonding fiber, and the end plate is bonded by a second heat-bonding fiber. The first fine-adhesive fiber and / or the second-adhesive fiber is made of the second nonwoven fabric having an average fineness of 5 to 30 dtex and a thickness of 1 to 5 mm. The filter element manufacturing method, wherein the filter element is bonded by the method.

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