JP5351656B2 - Method for fusing the endless part of the pre-filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for fusing the endless part of a pleated filter capable of easily forming the endless part excellent in endless strength by a simple method. <P>SOLUTION: The leading end of the endless part of the pleated filter comprising a polypropylene filter medium is applied to a thermally molten polypropylene sheet to be molten and fused so as to cover the outer periphery of the endless part of the pleated filter with the molten polypropylene sheet to enhance the endless strength of the endless part of the pleated filter. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for fusing an endless portion of a pre-filter, and more particularly to a method for fusing an endless portion that can easily form an endless portion having excellent endless strength.

  Conventionally, a method for fusing an endless portion of a pre-filter has been performed by using an ultrasonic welder device and applying ultrasonic waves to the endless portion to fuse the filter medium. However, particularly in the case of a filter in which filter media (nonwoven fabrics) are laminated in multiple layers, it has been difficult to fuse all the filter media through ultrasonic waves from one direction. This is because if the output is small, it does not fuse, and if the output is increased, the ultrasonic wave jumps and the filter medium is formed. When the ultrasonic jump occurs, there arises a problem that a hole is formed in the filter medium, and when the filter medium is formed into a film, there is a problem that the strength of the part adjacent to the filmed part becomes weak.

  Moreover, as shown in FIG. 1, a net is usually attached to the core side and cover side of the endless part, but the difference between the net part (resin part) and the inside of the lattice (space part) (unevenness, resin Therefore, there was a problem that welding could not be made uniformly, or ultrasonic jumping occurred due to the net filter medium. For this reason, as shown in FIG. 1, the work is performed by turning the net on the core side and the cover side, but there is a problem that the work becomes complicated and the work efficiency does not increase.

  Further, in the case of a filter medium in which a glass filter medium is bonded to the inner surface of a polypropylene filter medium, there is a problem that it is extremely difficult to find a fusion condition that does not leak.

  On the other hand, a method has been proposed in which an endless portion is gripped with a plastic clip and embossed and formed by ultrasonic fusion to be integrated (Patent Document 1).

  However, since this method is also based on ultrasonic fusion, as described above, there are problems associated with ultrasonic fusion, and this method has a problem that the end face of the endless portion is not sufficiently sealed.

Japanese Patent No. 3936188

  An object of the present invention is to provide a method for fusing an endless portion of a pre-filter that can easily form an endless portion having excellent endless strength by a simple method.

The configuration of the present invention that meets the above-described object is that the end of the endless part of the pre-filter made of polypropylene filter material is melted by being applied to the heat-melted polypropylene sheet, and then welded so that the outer periphery of the endless part is covered with the molten polypropylene sheet. It is characterized by that.

  It is preferable that a polypropylene sheet is housed inside the endless part tip, and the polypropylene sheet tip is melted and integrated with the molten polypropylene sheet (Claim 2).

  The pre-filter is suitable for application to a pre-filter provided with a support filter medium inside and outside a filter medium made of polypropylene nonwoven fabric.

  The polypropylene sheet is melted on a heater, and a weight plate slightly larger than the endless surface tip is placed on the polypropylene sheet, and the polypropylene sheet is sufficiently softened. It is preferable to melt by applying to a heat-melted polypropylene sheet.

The end of the endless part is preferably melted with a heater and temporarily fixed (Claim 5).
As the pre-filter, a pre-filter in which a glass fiber filter medium is housed in the polypropylene filter medium can be used (Claim 6).

  According to the present invention, since the end of the endless part is melted with the molten polypropylene sheet, the end of the endless part is inserted into the molten polypropylene and the outer periphery of the endless part is sandwiched so as to be covered with the molten polypropylene, so that the mechanical strength is remarkably improved.

It is the schematic which shows the endless process by the conventional ultrasonic wave. It is the schematic which shows the processing method of this invention. It is the schematic which shows the state processed by the conventional method and this invention method.

  Next, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 2, a polypropylene sheet (having a thickness of about 0.8 mm) is placed on a heater heated to about 240 ° C. At this time, a PTFE sheet or a Teflon (registered trademark) coated heater is used. This is because the molten polypropylene sheet adheres to the heater when placed directly on a normal heater.

  Then put the weight on the polypropylene sheet. The size of the weight is slightly larger than the end face of the endless part of the pleated filter.

  On the other hand, the end of the endless part is temporarily fixed by melting with a heater. If both ends of the endless portion can be held so as not to be separated, it can be processed using other means such as a simple jig without temporarily fixing.

  The weight is removed and the end face of the endless part temporarily fixed is applied to the molten polypropylene sheet and melted. In this embodiment, since the polypropylene sheet is housed in the end portion of the endless portion, the end of the polypropylene sheet is also fused and integrated with the molten polypropylene sheet.

  The molten polypropylene sheet is lifted in a state where the molten polypropylene sheet is welded to the end face of the endless part, put into a mold, and hardened so that the outer periphery of the endless part is wrapped with the polypropylene sheet. Of course, instead of putting in a mold, a hinge-type jig may be used so that the polypropylene sheet wraps the outer periphery of the endless portion.

As shown in FIG. 3, the seal part formed in this way is in a state where the pleat tip is melted and stuck in polypropylene, and in this state, the outer periphery of the endless portion is sandwiched between polypropylene. Therefore, the mechanical strength is remarkably improved.
Further, in this embodiment, since the polypropylene sheet provided at the end of the endless portion is integrated with the molten polypropylene sheet and the end melting portion, the mechanical strength is also improved for this reason.

  As shown in FIG. 3, the prep filter is suitable for application to a prep filter in which a support filter medium is provided inside and outside the main filter medium and the pre-filter medium on the outer periphery thereof. The main filter medium, the pre-filter medium, and the support filter medium are made of polypropylene, and the main filter medium and the pre-filter medium may be non-woven fabrics, membranes, and calendar filter media. The support filter medium is a net or non-woven fabric, but the effect is particularly great when used in a net. The main filter medium is suitable for use in a laminate of non-woven fabrics and the like in multiple layers. The pre-filter medium and the support filter medium may be omitted.

  The material of the filter used in the present invention needs to be polypropylene, but the outside that contacts the molten polypropylene sheet may be polypropylene, and the inside may be a different material such as a glass filter medium. This is because the molten polypropylene sheet and the polypropylene on the front end surface are integrated, and the external polypropylene can wrap the molten polypropylene sheet.

The following test was conducted on the filter having the endless part fused as described above. The support filter medium is a net, and is a main filter medium, pre-filter medium leaves, and non-woven fabric.
Invention product A: Manufactured as shown in FIGS.
Invention product B: Manufactured as shown in FIGS. 2 and 3 except that no polypropylene sheet was placed inside.
Invention product C: Manufactured as shown in FIGS. 2 and 3 except that it does not include internal and external net supports.
Invention product D: Manufactured as shown in FIGS. 2 and 3 except that the inner and outer net supports were not included and a polypropylene sheet was not inserted inside.
Conventional product: manufactured by turning the net as shown in FIG. 1 and FIG.
1. Leak test The initial foaming pressure between the filter medium itself and the endless part was compared by a 60% IPA reverse pressure leak test. The results are shown in Table 1 below.

２．引張試験
（１）ネットサポートを含まないフィルターについて、従来法(超音波を使用)と本発明法とで融着したフィルターについて、エンドレス強度を比較した。結果を次表２に示す。

2. Tensile test (1) For filters not including a net support, endless strength was compared for filters fused by the conventional method (using ultrasonic waves) and the method of the present invention. The results are shown in Table 2 below.

本発明法で融着したフィルターは、従来法で融着したフィルターよりも、エンドレス強度が約１０倍向上していた。
（２）ネットサポートを含んだ本発明法で融着したフィルターについてのエンドレス強度を測定した。結果は、次表３に示す。

The filter fused by the method of the present invention had an endless strength about 10 times higher than the filter fused by the conventional method.
(2) The endless strength of the filter fused by the method of the present invention including the net support was measured. The results are shown in Table 3 below.

ネットも一緒にエンドレスするため、強度アップにつながった。
３．耐久性試験（常温による耐久性試験）
耐圧試験(正圧0.55MPA×パルス100回)後、６０％ＩＰＡ逆圧リークテストによって発泡圧を確認した。

The net is also endless together, leading to increased strength.
3. Durability test (Durability test at normal temperature)
After the pressure resistance test (positive pressure 0.55 MPa × pulse 100 times), the foaming pressure was confirmed by a 60% IPA reverse pressure leak test.

  As a result, none of the products A, B, C and D of the present invention leaked to the in-house pressure resistance standard (0.49 MPa).

According to the present invention, endless processing with extremely high endless strength can be performed without causing the problems associated with ultrasonic processing, so that it is expected to be adopted for mass production.

Claims (6)

The endless part of the pre-filter made of polypropylene filter medium is melted by applying it to a heat-melted polypropylene sheet, and then welded so that the outer periphery of the endless part is covered with molten polypropylene. Fusion method. The fusion bonding method according to claim 1, wherein a polypropylene sheet is housed in the end portion of the endless portion, and the tip portion of the polypropylene sheet is fused and integrated with the molten polypropylene sheet. The fusing method according to claim 1 or 2, wherein the prep filter is a prep filter in which a support filter medium is provided inside and outside a filter medium made of polypropylene. The polypropylene sheet is melted on a heater and a weight plate slightly larger than the end surface of the endless part is placed on the polypropylene sheet. When the polypropylene sheet is sufficiently softened, the end of the endless part is removed from the heat by removing the weight plate. The fusion bonding method according to any one of claims 1 to 3, wherein the fusion is performed by applying the molten polypropylene sheet. The fusion bonding method according to claim 1, wherein the end of the endless part is melted with a heater and temporarily fixed. The fusion method according to any one of claims 1 to 5, wherein the prep filter is a prep filter in which a glass fiber filter medium is housed in the polypropylene filter medium.

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