Filter element and method for manufacturing the same

Abstract

To provide a filter element hard to be damaged and easily adjusted when an external force is applied.SOLUTION: This filter element comprises two beltlike frame members, and there are two places in which both end edges in a long side direction thereof are stacked and bonded in the two beltlike frame members. As compared with a conventional filter element which includes four beltlike frame members and in which the number of joints of the end edges of the beltlike frame members is four, in the filter element, the number of joints of the end edges of the beltlike frame members is smaller, that is, two, and both end edges of the joints are staked and bonded. Thus, the number of joints of the end edges of the less rigid beltlike frame members is smaller, and as the joints are stacked and bonded, the joints are higher in strength and the filter element is hard to be damaged.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pleated filter medium having a rectangular shape when viewed from the main surface side, a filter element including a strip-shaped frame member on the outer periphery of the rectangle, and a method for manufacturing the same.

Background Art

[0002] Conventionally, in order to keep the pleat interval of a pleated filter medium having a rectangular shape when viewed from the main surface side and repeatedly formed with pleats constant, and to provide a filter element rich in rigidity, a strip-shaped frame member (hereinafter sometimes referred to as a strip-shaped frame member) is adhesively provided on the outer periphery of the rectangle in the pleated filter medium.

[0003] For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-239120) discloses a filter element including side plates and reinforcing plates on the outer periphery when the pleated filter medium is viewed from the main surface side. In Patent Document 1, side plates or reinforcing plates are respectively adhered to the four sides on the outer periphery, and the ends of the side plates and / or reinforcing plates adjacent to each other at the four corners on the outer periphery are joined.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the filter element according to the prior art, at its four corners, there are joint portions between the ends of the strip-shaped frame members respectively. Therefore, when an external force acts on the filter element, the joint portion, which is a portion with inferior rigidity, comes off, and the filter element is likely to be damaged. Further, since four strip-shaped frame members have to be individually adhered to the pleated filter medium, the preparation of the filter element is complicated.

[0006] The present invention has been made under such circumstances, and an object thereof is to provide a filter element that is less likely to be damaged when an external force acts thereon and is easy to prepare.

Means for Solving the Problems

[0007] The invention according to claim 1 of the present invention is a "filter element comprising two strip-shaped frame members and a pleated filter medium having a rectangular shape when viewed from the main surface side, wherein the two strip-shaped frame members are adhered on the outer periphery of the rectangle in the pleated filter medium, and both ends of the two strip-shaped frame members in the long side direction thereof overlap and are adhered to each other, and the location where both ends overlap and are adhered is present on two sides of the outer periphery of the rectangle that are orthogonal to the direction in which the pleats are repeatedly formed in the pleated filter medium, filter element."

[0008] The invention according to claim 2 of the present invention is as follows: "(1) A step of preparing two strip-shaped frame members and a pleated filter medium having a rectangular shape when viewed from the main surface side. The two strip-shaped frame members have long sides that are parallel to the direction (direction A) in which pleats are repeatedly formed when viewed from the main surface side of the pleated filter medium, and are longer than the sides (side a and side b) on the outer periphery of the rectangle. The sum of the lengths of the long sides of the two strip-shaped frame members is longer than the outer periphery of the rectangle. (2) A step of adhering the two strip-shaped frame members to side a and side b respectively. In this step, the two strip-shaped frame members are adhered such that both ends in their length directions protrude from side a and side b. (3) A step of bending both ends in the length direction of the two strip-shaped frame members adhered so as to protrude in (2), and adhering both ends to two sides on the outer periphery of the rectangle that is perpendicular to direction A in the pleated filter medium. In this step, the two strip-shaped frame members are adhered such that both ends in their respective long side directions overlap each other.", which is a method for manufacturing a filter element.

Advantages of the Invention

[0009] The filter element according to claim 1 of the present invention has two strip-shaped frame members, and there are two locations where both ends in the respective long side directions of the two strip-shaped frame members overlap and are adhered to each other. Compared with a filter element according to the prior art that has four strip-shaped frame members and four joining portions between the ends of the strip-shaped frame members, the filter element according to the present invention has fewer joining portions between the ends of the strip-shaped frame members existing in the filter element, which is two, and moreover, the joining portions are where both ends overlap and are adhered to each other. Therefore, there are fewer joining portions between the ends of the strip-shaped frame members, which are inferior in rigidity, and since these joining portions overlap and are adhered to each other, the strength of the joining portions is high, making the filter element less likely to be damaged. Further, this joint portion is present on two sides out of the four sides on the outer periphery of the pleated filter medium, which are orthogonal to the direction in which the pleat folds are repeatedly formed. Among the four sides of the outer periphery of the pleated filter medium, the two sides parallel to the direction in which the pleat folds are repeatedly formed have the strip-shaped frame member adhered thereto so as to maintain the pleated state. However, since the adhesion of these two sides is in the pleated shape, the shape is complicated, and even if it is a single strip-shaped frame member, a gap is likely to occur between the strip-shaped frame member and the pleated filter medium, and leakage during use is likely to occur. On the other hand, the two sides orthogonal to the direction in which the pleat folds are repeatedly formed have straight ends of the pleated filter medium and a simple shape. Therefore, even if two strip-shaped frame members are adhered to these two sides, a gap is less likely to occur between the strip-shaped frame member and the pleated filter medium, and leakage during use is less likely to occur. Furthermore, since there are at least two strip-shaped frame members adhered to the filter element, the adhesion of the strip-shaped frame member is simple, and the filter element can be easily prepared.

[0010] By the manufacturing method of the filter element according to claim 2 of the present invention, a filter element having the configuration according to the present invention can be manufactured. Thereby, it is possible to provide a filter element that is less likely to be damaged when a force acts and is easy to prepare.

Brief Description of Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] The present invention is not limited to only the specific exemplary conditions described below, and any suitable design changes can be made within the scope of the object of the present invention.

[0013] Hereinafter, the details of the filter element and its manufacturing method according to the present invention will be described by exemplifying a preferred embodiment.

[0014] The filter element (1) of the present invention includes two strip-shaped frame members (2) and a pleated filter medium (3) having a rectangular shape when viewed from the main surface side, as exemplified in the perspective view in FIG. 1 and the view showing from the main surface direction in FIG. 2. These two strip-shaped frame members (2) are adhered onto the outer periphery of the rectangle in the pleated filter medium (3) (the outer periphery of the pleated filter medium (3) shown in FIG. 2). And both ends of these two strip-shaped frame members (2) overlap and adhere to each other in the long side direction, and the portions (4) where both ends overlap and adhere are each present on two sides on the outer periphery of the rectangle orthogonal to the direction in which the pleats are repeatedly formed in the pleated filter medium (3). By the portions (4) where both ends overlap and adhere being each present on two sides on the outer periphery of the rectangle orthogonal to the direction (direction A) in which the pleats are repeatedly formed in the pleated filter medium (3), the pleats of the pleated filter medium (3) can be fixed by the strip-shaped frame members (2).

[0015] In the filter element, in the aspect where there is a portion on two sides of the outer periphery of the rectangle that is parallel to the direction A and where both ends of the strip-shaped frame member overlap and adhere to each other, there will be a portion where both ends of the strip-shaped frame member overlap and adhere to each other at the portion where the strip-shaped frame member is adhered so as to maintain the pleated state. Since this portion is adhered in a pleated shape, the shape is complex. Even if it is a single strip-shaped frame member, a gap is likely to occur between the strip-shaped frame member and the pleated filter medium, and leakage during use is likely to occur. When the pleated shape of one side of the filter element is fixed by two strip-shaped frame members, the possibility of a gap occurring between the strip-shaped frame member and the pleated filter medium is greater than when the pleated shape of one side of the filter element is fixed by a single strip-shaped frame member. Therefore, the aspect where there is a portion on two sides of the outer periphery of the rectangle that is parallel to the direction A and where both ends of the strip-shaped frame member overlap and adhere to each other is not suitable.

[0016] Note that the "main surface" refers to the widest surface. Also, the vertical lines of the pleated filter medium (3) shown in the figure mean the crests or troughs of the pleats, and the direction (direction A) in which the pleats are repeatedly formed is the horizontal direction indicated by the arrow in Figure 2.

[0017] The filter element according to the prior art has four strip-shaped frame members, one for each of the four sides of the rectangle of the pleated filter medium. Therefore, the number of joining portions between the ends of the strip-shaped frame members present in the filter element is four in total, one at each of the four corners of the rectangle.

[0018] On the one hand, the filter element of the present invention has two strip-shaped frame members (2), and there are two locations (4) where both ends of the two strip-shaped frame members (2) overlap and adhere to each other in the long side direction. As a result, compared with the conventional filter element (1) having four strip-shaped frame members (2), the number of locations (4) where both ends of the strip-shaped frame members (2) with inferior rigidity in the filter element (1) overlap and adhere to each other in the long side direction is reduced to two. Moreover, at this location (4), both ends overlap and adhere to each other. Further, this location (4) exists on two sides of the outer periphery of the pleated filter medium (3) that are orthogonal to the direction in which the pleats of the pleated filter medium (3) are repeatedly formed and are not related to the fixation of the pleat shape. Therefore, the joint portion between the ends of the strip-shaped frame members (2) with inferior rigidity is small, and since this joint portion overlaps and adheres, the strength of the joint portion is high. Additionally, since this joint portion is not at the four corners of the pleated filter medium (3), the filter element (1) is less likely to be damaged. Also, the number of strip-shaped frame members (2) adhered to the filter element (1) is as few as two, and the locations (4) where both ends overlap and adhere to each other exist on two sides of the four sides of the outer periphery of the pleated filter medium (3) that are orthogonal to the direction in which the pleats of the pleated filter medium (3) are repeatedly formed. The two sides of the pleated filter medium (3) that are orthogonal to the direction in which the pleats are repeatedly formed have straight ends of the pleated filter medium (3) and a simple shape. Therefore, even if two strip-shaped frame members (2) are adhered to these two sides, it is difficult for a gap to occur between the strip-shaped frame members (2) and the pleated filter medium (3), and it is difficult for leakage to occur during use.

[0019] The strip-shaped frame member (2) constituting the filter element (1) can be, for example, non-woven fabric, woven or knitted fabric, film, foamed resin plate, resin thin plate, metal thin plate, etc. For example, when the strip-shaped frame member (2) is non-woven fabric or foamed resin plate, while maintaining a certain degree of strength, it also has a large thickness and has cushioning properties. Therefore, it is preferable in terms of excellent airtightness between the filter element (1) and the frame for attaching the filter element (for example, the frame provided in the air conditioning equipment of a vehicle).

[0020] The thickness of the strip-shaped frame member (2) is not particularly limited, but is preferably 0.3 to 6.0 mm, more preferably 0.4 to 5.0 mm, and still more preferably 0.5 to 4.0 mm. Note that the thickness in the present invention refers to the arithmetic mean value of the values measured at five points under a 2 kPa load.

[0021] The total length of the two strip-shaped frame members (2) in the long side direction surrounds the outer periphery of the rectangle visible when the pleated filter medium (3) is viewed from the main surface side with the two strip-shaped frame members (2), and both ends in the long side direction can overlap and be adhered. Therefore, the total length of the two strip-shaped frame members (2) in the long side direction needs to be longer than the length of the outer periphery of the rectangle. Note that the lengths of the two strip-shaped frame members (2) in the long side direction may be the same or different.

[0022] The width direction length orthogonal to the long side direction length of the strip-shaped frame member (2) needs to be such that the pleat shape of the pleated filter medium (3) can be fixed by the strip-shaped frame member (2). The preferred width direction length varies depending on the pleat height of the pleated filter medium (3).

[0023] The pleated filter medium (3) constituting the filter element is pleated by repeatedly folding a sheet-shaped filter medium so as to alternately have mountain folds and valley folds using a pleating device or the like. The material of the pleated filter medium (3) can be, for example, a non-woven fabric, a woven fabric, a knitted fabric, or a microporous membrane, but is preferably a non-woven fabric in terms of ease of pleating. Also, the thickness of the sheet-shaped filter medium constituting the pleated filter medium (3) is not particularly limited, but is preferably 0.2 to 5.0 mm, more preferably 0.3 to 4.0 mm, and still more preferably 0.4 to 3.0 mm.

[0024] Regarding the method of adhering the belt-shaped frame member (2) to the pleated filter medium (3), for example, a method of melting a part of the belt-shaped frame member (2) and adhering it to the pleated filter medium (3), a method of applying or spraying an adhesive resin or a hot-melt resin to the belt-shaped frame member (2) or the pleated filter medium (3) for adhesion, or a method of providing a sheet of hot-melt resin adjacent to the belt-shaped frame member (2), melting the hot-melt resin, and adhering the belt-shaped frame member (2) and the pleated filter medium (3) through the hot-melt resin can be used. Regarding these adhesion methods, when adhering with an adhesive resin or a hot-melt resin, the resin constituting them is not particularly limited, but for example, it can be a thermoplastic resin such as ethylene vinyl acetate-based, thermoplastic polyurethane resin-based, polyamide-based, polyester-based, polyolefin-based, or styrene block polymer.

[0025] Next, the manufacturing method of the filter element (1) of the present invention will be described.

[0026] First, two belt-shaped frame members (2) and a pleated filter medium (3) having a rectangle when viewed from the main surface side are prepared. Note that these two belt-shaped frame members (2) have long sides that are longer than the sides (side a and side b) on the outer periphery of the rectangle of the pleated filter medium (3), and the total length of the long sides is longer than the outer periphery of the rectangle. The side a and side b refer to the sides (the upper and lower sides in FIGS. 2 to 4) that are parallel to the direction in which the pleats are repeatedly formed in the filter element (1) or the pleated filter medium (3) shown in FIGS. 2 to 4.

[0027] Next, as shown in FIG. 3, two strip-shaped frame members (2) are adhered to the sides a and b of the pleated filter medium (3), respectively. In this step, the two strip-shaped frame members (2) are adhered such that both ends in their length directions protrude from the sides a and b. By fixing the pleat folds of the pleated filter medium (3) with the two strip-shaped frame members (2) in this step, the pleat shape is less likely to shift during the manufacture of the filter element (1), and the filter element (1) can be easily prepared. At this time, as the method of adhering the strip-shaped frame member (2) to the pleated filter medium (3), as described above, for example, a method of melting a part of the strip-shaped frame member (2) and adhering it to the pleated filter medium (3), a method of applying or spraying an adhesive resin or a hot-melt resin to the strip-shaped frame member (2) or the pleated filter medium (3) for adhesion, or a method of providing a sheet of hot-melt resin adjacent to the strip-shaped frame member (2) and melting the hot-melt resin to adhere it to the pleated filter medium (2) can be used.

[0028] Next, as shown in FIG. 4, both ends in the length direction of the two strip-shaped frame members (2) adhered so as to protrude in the previous step are bent, and the both ends are adhered to two sides on the outer periphery of the rectangle perpendicular to the direction A in the pleated filter medium (3), respectively. In this step, the two strip-shaped frame members (2) are adhered such that both ends in their respective long-side directions overlap each other. In FIG. 2, the upper strip-shaped frame member (2) in FIG. 4 is adhered so as to cover the lower strip-shaped frame member (2), but the lower strip-shaped frame member (2) in FIG. 4 may be adhered so as to cover the upper strip-shaped frame member (2). Also, the length in the long-side direction of the strip-shaped frame member (2) at the portion where both ends of the strip-shaped frame member (2) overlap can be 0.3 to 6 cm, can be 0.5 to 4 cm, and can be 1 to 2 cm.

Industrial Applicability

[0029] The filter element of the present invention can be suitably used in applications such as automotive cabin air filters, filters for air purifiers, and filters for building air conditioners.

Explanation of Reference Numerals

[0030] 1: Filter element 2: Strip-shaped frame member 3: Pleated filter medium 4: Portion where both ends in the long side direction of the strip-shaped frame member overlap and adhere to each other a: One side on the outer periphery parallel to the direction in which the pleats are repeatedly formed in the pleated filter medium having a rectangular shape b: The other side on the outer periphery parallel to the direction in which the pleats are repeatedly formed in the pleated filter medium having a rectangular shape A: Direction in which the pleats are repeatedly formed in the pleated filter medium

Claims

1. A filter element comprising two strip-shaped frame members and a pleated filter medium having a rectangular shape when viewed from the main surface side, wherein the two strip-shaped frame members are adhered onto the outer periphery of the rectangle in the pleated filter medium, wherein the two strip-shaped frame members have their both end portions in the long side direction thereof overlapping and adhered to each other, wherein the portions where the both end portions overlap and are adhered are respectively present on two sides of the outer periphery of the rectangle that are perpendicular to the direction in which the pleats are repeatedly formed in the pleated filter medium, a filter element.

2. (1) A step of preparing two strip-shaped frame members and a pleated filter medium having a rectangular shape when viewed from the main surface side, wherein the two strip-shaped frame members have long sides that are longer than the sides (side a and side b) of the outer periphery of the rectangle and are parallel to the direction (direction A) in which the pleats are repeatedly formed when viewed from the main surface side in the pleated filter medium, and the sum of the lengths of the long sides of the two strip-shaped frame members is longer than the outer periphery of the rectangle, (2) A step of adhering the two strip-shaped frame members to side a and side b respectively, wherein in this step, the two strip-shaped frame members are adhered such that both end portions in their length directions protrude from side a and side b respectively, (3) A step of bending both end portions in the length direction of the two strip-shaped frame members adhered so as to protrude in (2), and adhering the both end portions to two sides of the outer periphery of the rectangle in the pleated filter medium that are perpendicular to direction A, wherein in this step, the two strip-shaped frame members are adhered such that both end portions in the long side direction thereof overlap each other, a method for manufacturing a filter element.

Images