JP4063009B2 - Folding filter and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a folding filter that can be used for an air filter, a liquid filter, and the like, and a method for manufacturing the same.
[0002]
[Prior art]
A folding filter is known in which a sheet material is bonded to the top and bottom of a pleated filter medium and the sheet material is cut at predetermined intervals (Japanese Patent Laid-Open No. 7-112108). However, in the folding filter having such a configuration, the pleat pitch of the pleated filter medium is distorted due to accumulation of fluctuation errors in the pitch between the filter mediums, and therefore, when cutting with the same frame length, the cut portions do not always match. Therefore, when trying to cut at a predetermined position, the filter medium itself may have to be cut, and in such a place, there is a problem that air etc. leaks when used as a folding filter. It was. Further, dust may be generated when the sheet material is cut.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-described problems of the conventional folding filter and to provide a high-quality folding filter with a high yield. Another object of the present invention is to provide a method for manufacturing such a folding filter at low cost.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the folding filter of the present invention is configured so that the top and bottom portions of the pleated filter medium correspond to the tape body having the notched portion when expanded, and the pleated bottom portion of the pleated filter medium corresponds to the bottom of the notched portion. When bonded and spread, the pleat pitch of the pleated filter medium in the notch portion is larger than the pleat pitch in other portions .
[0005]
Here, the notch is preferably wedge-shaped.
[0007]
The folding filter preferably has a U-shaped, square-shaped or zigzag folded shape. Here, the U-shape refers to a shape as shown in FIG. 4 in which both ends in the longitudinal direction of the tape body are bent in the same direction, and the B-shape has at least three folding portions. The shape that the both ends of a tape body are joined is said. By providing the tape body with the shape and position of the cutout portion in accordance with the desired folding shape, a folding filter that matches the shape and required performance of the air cleaner or the like can be obtained.
[0008]
In addition, the method for manufacturing a folding filter of the present invention for achieving the above object is characterized in that hot melt resin is applied, the hot melt resin of the tape body having an incision is melted, and the tape body is placed on the top and bottom of the pleated filter medium. A folding filter manufacturing method in which a pleat filter medium is joined to the incision portion so that the pleat bottom portion corresponds, and then the pleat filter material is bent at the incision portion, wherein the pleat has a pitch increased in advance at the joint portion. A tape body is joined to the filter medium .
[0010]
In the folding filter manufacturing method of the present invention, it is preferable to use a tape body in which an incision portion is formed by a notch.
[0011]
Moreover, it is preferable that the thermal contraction rate of a tape body is 5% or less.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a folding filter in which a top and bottom portion of a pleated filter medium is joined to a tape body having a notch portion when stretched, and a pleat bottom portion of the pleat filter medium corresponds to a bottom portion of the notch portion.
[0013]
The tape body is made of polyester fiber, rayon fiber, pulp fiber, kenaf fiber, glass fiber and other short fibers made of resin, such as hardened with resin, or fiber sheets such as spunbond nonwoven fabric are processed into a tape body. However, it is particularly preferable to use a filter paper sheet prepared by a papermaking method as a tape body. Those obtained by laminating a bulky nonwoven fabric having a fiber density of about 0.09 g / cm ^{3 on} these tape bodies can also be used as the tape body.
[0014]
The tape body is provided with a notch, and the pleat bottom of the pleat filter medium is joined to correspond to the bottom of the notch to constitute a filter. Since the tape body has the cutout portion, the filter can be easily bent into a desired shape, and the cutout portion of the tape body and the pleat filter medium are joined as described above, so that Therefore, a suitable folding filter can be obtained. The tape body serves as a frame material for the folding filter.
[0015]
The shape of the notch can be rectangular, U-shaped, V-shaped, or the like, but is preferably wedge-shaped. In particular, it is preferable from the viewpoint of safety that the shape of the cut-out portion is an obtuse angle (θ) formed by the upper side 6 of the frame member and the cut line 5 as shown in FIG. It is also preferable to round the corners of the notch.
[0016]
In the pleat filter medium to be joined to the tape body, it is preferable that the pitch of the pleats is larger than the pitch of the pleats in other parts at the part corresponding to the notch part of the tape body to be joined.
[0017]
In the folding filter of the present invention, after forming the incision portion 2 in the tape body 1 to which the hot melt resin is applied, the hot melt resin is melted, and the tape body 1 is placed in the incision portion 2 in the top and bottom portion of the pleated filter medium 3. The pleat filter medium 3 can be manufactured by joining so that the bottoms 4 of the folds correspond to each other, and then bending the pleat filter medium at the incision 2 (FIGS. 3 and 4).
[0018]
Alternatively, the hot melt resin is applied to the tape body 1 in which the incision portion 2 is formed, and then the hot melt resin is melted, and the tape body 1 is formed on the top and bottom portions of the pleat filter medium 3 and the pleat filter medium 3 is formed on the cut portion 2. It can also be manufactured by joining so that the bottom part 4 of the fold corresponds, and then bending the pleated filter medium 3 at the incision part 2.
[0019]
In these cases, it is preferable to use a tape body in which an incision is formed by a notch. When the incision is a simple cut, the tape body at the cut portion is not separated when the tape body 1 and the pleat filter medium 3 are bonded, so the cut itself is easily fixed by the adhesive, and the cut surface is dissociated. In order to achieve this, cutting must be performed again, which complicates the process and decreases the yield.
[0020]
When joining the tape body 1 and the pleat filter medium 3, it is preferable that the pitch La of the pleats of the pleat filter medium 3 is preliminarily widened at the portion to be joined to the notch portion of the tape body. As shown in FIG. 3, by attaching the filter medium pitch Lb, which is a folded portion, larger than the size of the notch, the position of the folded portion and the notched portion is properly bonded, and thus the folding filter having a clean shape is efficiently attached. Can be manufactured. The pleat filter medium is preferably set in advance in an assembly jig that can adjust the pleat interval to the dimensions of the tape body and then joined to the tape body.
[0021]
The tape body preferably has a heat shrinkage of 5% or less, particularly 1% or less. On the tape body, the hot melt resin is generally applied to a thickness of 1.2 mm or less before or after the formation of the notch, and then the hot melt resin is melted and joined to the pleated filter medium. As shown in FIG. 3, it is necessary to align the notch 2 of the tape body 1 and adhere to the space formed between the pleats of the pleat filter medium 3 (between the peaks). If the thermal shrinkage rate is greater than 5%, the tape body is likely to undergo dimensional changes in the melting process of the hot melt resin, and the positional relationship between the notched portion of the tape body and the folded portion of the pleat filter medium is displaced, resulting in predetermined adhesion. It becomes difficult to adjust the position. On the other hand, if the shrinkage rate is too large, the pleated filter medium is deformed by being pulled by the shrinkage of the tape body after the hot melt resin is solidified, so that a filter having a specified size cannot be obtained. Therefore, the thermal contraction rate of the tape body is better as it is closer to 0%. The heat shrinkage ratio is obtained as a ratio of the shrinkage amount (longitudinal direction) after heating to the dimension (longitudinal direction) before heating after the tape body is dry heat treated at 180 ° C for 5 minutes and then cooled to 25 ° C. A filter paper-like sheet produced by the papermaking method and used as a tape body has a small thermal shrinkage and can be suitably used.
(Example)
The present invention will be described in more detail with reference to examples.
Example 1
As a tape body, the basis weight is 180 g / m ^{2 in} which short fibers containing 70% polyester fiber (3 denier, fiber length 5 mm), 15% pulp, and 15% glass fiber having a fiber diameter of about 7 μm are solidified with an acrylic resin. The fiber sheet of the papermaking method was used. A hot melt resin (Hirodyne Co., Ltd. type 8600S) was applied to this with a thickness of 0.6 mm. The shrinkage of the tape body at 180 ° C. was 0.7%.
[0022]
A tape body coated with this hot melt resin is finished to the notch dimensions shown in FIG. 2, and a pleated filter material having a height of 14 mm, a height of 136, and an average pitch of 3.69 mm is prepared. The average pitch at the mountain (73 mm position) position was enlarged to 5 mm and held. The tape body was bonded to both ends (top and bottom portions) of the pleated filter medium after dissolving the hot melt resin.
[0023]
The hot melt resin was cooled, and a U-shaped filter that could be bent at a position of 73 mm could be obtained.
[0024]
Schematic diagrams seen from above the tape body of the filter (the number of peaks, the pitch, etc. are schematically shown and differ from the actual one) are shown in FIGS. 3 (before folding) and 4 (after folding).
[0025]
Example 2
A polyester spunbonded nonwoven fabric (thermal bonding type, Toray AXTAR, G2080) was used as the tape body, and the same hot melt resin as in Example 1 was applied to a thickness of 0.6 mm. The shrinkage rate at 180 ° C. was 2.5% in the MD direction (vertical direction of the nonwoven fabric) and 1% in the CD direction (horizontal direction of the nonwoven fabric). When a notch is provided and joined to the same pleat filter medium as in Example 1, a notch portion of the tape body can be attached to a predetermined position of the pleat, and a folding filter that can be bent and has high dimensional accuracy is obtained. I was able to.
[0026]
Comparative Example 1
A polyester short fiber needle punched nonwoven fabric (3 denier, fiber length 51 mm, basis weight 250 g / m ² ) was used as the tape body, and the same hot melt resin as in Example 1 was applied at a thickness of 0.6 mm. The tape body was affixed to the end of the pleated filter medium with a peak height of 14 mm, a peak number of 136, and an average pitch of 3.69 mm without providing a cutout in the tape body. I tried to cut the frame material at the valley of the position), but there was uneven filter media pitch, so it was impossible to cut at the position of 73 mm of the same frame, and it would cut at 72.1 mm and 74.3 mm The frame length could not be made uniform.
[0027]
【The invention's effect】
The folding filter of the present invention can be folded by using a tape body having a notch in advance as a frame material for the pleated filter medium, and is beautiful at the notched portion and has excellent quality.
[0028]
The folding filter of the present invention can be particularly suitably used for an air purifier in which vent holes are formed not only on the front surface but also on the side surface and the back surface.
[Brief description of the drawings]
FIG. 1 is a schematic view of a notch when a tape body used in the present invention is stretched.
FIG. 2 is a shape after cutting out the tape bodies of Examples 1 and 2.
FIG. 3 is a perspective view (schematic diagram) of the folding filter according to the first embodiment as seen from the tape body side before folding.
4 is a perspective view (schematic diagram) of the folding filter according to the first embodiment when viewed from the tape body side after folding. FIG.
[Explanation of symbols]
1. 1. Tape body 2. Notch 3 3. Pleated filter medium 4. Fold bottom 5 Cut line 6. Top line

Claims (6)

When stretched, the pleated filter medium top and bottom part is joined to the tape body having the cutout part so that the pleat filter medium pleat bottom part corresponds to the cutout part bottom part. Folding filter in which the pleat pitch of the pleat filter medium is larger than the pleat pitch of other parts . The folding filter according to claim 1, wherein the notch has a wedge shape .   The folding filter according to any one of claims 1 to 3, wherein the folded shape is a U-shape, a square shape, or a zigzag shape. Hot melt resin is applied, the hot melt resin of the tape body having an incision is melted, and the tape body is joined to the top and bottom of the pleated filter medium so that the pleat bottom of the pleat filter medium corresponds to the incision. A method for manufacturing a folding filter in which a pleated filter medium is bent at an incised portion, wherein the tape body is bonded to a pleated filter medium whose pitch is previously widened at a portion to be bonded to the incised section . The manufacturing method of the folding filter of Claim 4 using the tape body in which the incision part was formed by the notch. The method for producing a folding filter according to claim 4 or 5 , wherein the thermal contraction rate of the tape body is 5% or less.

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