JPH1176747A - Deodorizing filter medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a deodorizing effect and to realize low pressure loss by fixing deodorizing granules through a resin aggregate on one surface of a web comprising a hot-melt resin connecting part and the resin aggregate. SOLUTION: The web 15 consists of a connecting part 11 and a resin aggregate part 13 and both are consists of a hot-melt resin. The web 15 is obtd. by heat treating a hot-melt nonwoven fabric while the fabric is in contact with a deodorizing powder 17. As for the hot-melt resin from which the web above described can be produced, a thermoplastic polyamide resin, thermoplastic polyester resin, thermoplastic polyurethane resin, polyolefin resin, ethylene-vinyl acetate copolymer resin, etc., can be used in a single or mixed state. As for the deodorizing powder 17, the powder is preferably controlled to have the average particle size of >=0.147 mm (100 mesh) and <=1.65 mm (10 mesh) so as to obtain high efficiency and low pressure loss.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing filter for filtering and purifying a fluid contaminated with an odor component, and more particularly to a deodorizing filter having a low pressure drop and excellent deodorizing performance.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable increase in awareness of the living environment, and in particular, there has been a great deal of interest in odors. Removal is also required. In order to remove these odor components, various deodorizing filter media have been proposed. Most of such deodorizing filter media have particles made of, for example, activated carbon or various chemical deodorants (hereinafter, collectively referred to as deodorizing powders) fixed to a sheet-shaped member having air permeability. 2. Description of the Related Art As a conventionally known powder particle fixing technique, a method of using a variety of binders to fix and carry deodorized powder particles on a base fabric such as a nonwoven fabric has been widely performed. However, many of them have a defect that the surface of the deodorized powder particles is covered with the binder, so that the performance inherent in the powder particles is deteriorated.

[0003] On the other hand, for example, Japanese Patent Application Laid-Open No. Hei 8-26684.
No. 5 (hereinafter referred to as the document) proposes a 10 m
An emulsion-type acrylic pressure-sensitive adhesive is previously attached to a mesh having openings of m to 1 mm, and deodorized powder particles (adsorbing material particles) are fixed via the pressure-sensitive adhesive. In this technique, as disclosed in the publication, 1 mm to 10 m
A pressure-sensitive adhesive is applied to a net having openings of m with a spray or a coater.

[0004]

As described above, applications requiring a deodorizing function are diversified, and there are various required characteristics depending on equipment provided with a deodorizing filter medium. In order to improve the deodorizing efficiency, when designing a deodorizing filter medium, it is well known to employ a technique of increasing the arrangement density of the deodorizing powder granules to increase the probability of contact with odorous substances. Therefore, for example, by designing the mesh of the mesh disclosed in the above-mentioned publication to have a smaller opening, it is possible to improve the deodorizing efficiency, but on the other hand, the pressure loss also increases, and the applicable deodorizing equipment can be used. The degree of freedom is reduced. Furthermore, when such a net is used, for example, when the aperture is set to 100 μm or less, the opening portion is crushed in the step of applying the adhesive, and the actual pressure loss is significantly larger than the designed pressure loss. There was a problem.

[0005] In view of such conventional problems, the inventor of the present application uses a conventionally known nonwoven fabric made of a hot-melt resin, and adheres deodorized powder particles to the nonwoven fabric to remove odorous substances. Deodorizing filter media that can improve the probability of contact with deodorized powder and granules have been studied diligently. As a result, a deodorized filter medium with a low pressure loss that cannot be achieved by simply supporting the deodorized powder on the hot melt nonwoven fabric has been realized. Therefore,
An object of the present invention is to provide a deodorizing filter medium having high deodorizing efficiency and realizing low pressure loss.

[0006]

In order to achieve this object, according to the structure of the deodorizing filter medium of the present invention, one surface of a web constituted by a connecting portion made of a hot melt resin and a resin aggregation portion. In addition, a deodorized powder is fixed via the above-mentioned resin aggregation portion.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a deodorizing filter medium according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a filter medium of the present invention by a schematic cross section.

[0008] The web 15 constituting the deodorizing filter medium of the present invention comprises a connecting portion 11 and a resin aggregation portion 13, both of which are formed of a hot melt resin. The web 15 having such a configuration is obtained by subjecting a hot-melt nonwoven fabric to a heat treatment in contact with the deodorized powder 17 (detailed later).
Examples of the hot melt resin capable of forming such a web include a thermoplastic polyamide resin, a thermoplastic polyester resin, a thermoplastic polyurethane resin, a polyolefin resin, and an ethylene-vinyl acetate copolymer resin.
They can be used alone or in combination.

As the deodorizing powder and granules, various types of conventionally known activated carbon and other particulate chemical deodorizing agents can be selected and used. However, in order to achieve high efficiency and low pressure loss, the powder is required. It is preferable that the average particle diameter of the granules be 0.147 mm (100 mesh) or more and 1.65 mm (10 mesh) or less. When a deodorized powder having an average particle diameter smaller than the lower limit of the preferred range is used, the initial deodorization efficiency can be increased, but the pressure loss increases. further,
When a deodorized powder having an average particle diameter larger than the upper limit of the above-mentioned preferred range is used, the deodorizing efficiency tends to decrease.

Next, a manufacturing technique for realizing the deodorizing filter medium of the present invention will be described according to the manufacturing process. In the present invention, the heat treatment is performed in a state where the deodorized powder and granules are arranged in contact with the hot melt nonwoven fabric. The hot-melt nonwoven fabric used at this time is preferably made of the above-mentioned thermoplastic resin and has a surface density of 10 to 30 g / m ² ,
In particular, those having 15 to 25 g / m ² are preferable. If the areal density is smaller than these preferred ranges, the uniformity of the deodorized powder particles will be impaired due to lack of uniformity as a nonwoven fabric, and the efficiency of the deodorizing filter medium will be reduced due to leakage of odorous substances. In addition, even if it exceeds the above preferred range, no improvement in the fixing strength can be expected, and only the pressure loss as the deodorizing filter medium increases.

[0011] Further, the opening diameter of the hot melt nonwoven fabric used in the present invention is desirably smaller than the desired particle size of the powdered granules in order to uniformly carry the deodorized powders in the obtained deodorizing filter medium. . For example, when the particle size of the deodorized powder is about 32 mesh (about 500 μm), it is preferable to select and use the above-mentioned hot melt nonwoven fabric so that the web opening diameter after the heat treatment is 100 μm or less. .

[0012] In order to realize the structure of the present invention, the fibers constituting the hot melt nonwoven fabric are plasticized and melted by a heat treatment, and a part thereof is melt-cut due to a small fiber diameter and is in contact with deodorized powder particles. To form a resin aggregation portion. This point will be described with reference to FIG. 2 showing a plane from the web 15 side by focusing on one of the deodorizing powder granules 17 in the deodorizing filter medium shown in FIG. At the same time, if the fiber diameter is relatively large, cutting is delayed even after plasticizing and melting.
As 1, a strong network structure is formed. In this heat treatment, for example, a calender, an infrared heater, a hot air heater, and the like can be a conventionally known means, such as heating with steam, but in order to efficiently form a resin aggregation portion and realize a low pressure loss. In particular, it is preferable to perform the heat treatment in the presence of a fluid having a calorific value such as hot air or steam.
Further, as a particularly preferred embodiment, a hot melt nonwoven fabric made of a thermoplastic polyamide-based resin or an ethylene-vinyl acetate copolymer resin is used, and by employing a heat treatment with steam, the resin is easily shrunk and cut when wet and heated. Therefore, the above-mentioned melt cutting can be efficiently performed. Further, when it is necessary to compensate for a decrease in strength due to plasticization and melting of the hot melt nonwoven fabric, a filter material for collecting dust may be added as a support of the hot melt nonwoven fabric constituting the outermost layer of the deodorizing filter medium. .

Hereinafter, embodiments of the present invention will be described. However, the following embodiments are merely preferred examples for facilitating the understanding of the present invention, and the present invention is limited only to these exemplary conditions. is not.

[0014]

First, a spunbond made of polyester and having an areal density of 30 g / m ² was used as a support, and the support was made of a thermoplastic polyamide resin having an areal density of 20 g / m ^2.
keep stacking the m ² of hot melt non-woven fabric. Then, on the surface of the hot melt nonwoven fabric thus laminated, 32 to
A commercially available activated carbon (weight average particle size: 0.375 mm) classified into 60 mesh is sprayed. Then, about 5Kg / cm
The steam treatment of ² is performed for about 7 seconds from the support side (hot-melt nonwoven fabric side), and the hot-melt nonwoven fabric is plasticized and melted. The activated carbon was fixed through the agglomerated part. Subsequently, the deodorized powder particles were fixed at 130 g / m ² by removing the other than the fixed activated carbon, and a deodorizing filter medium according to the example was further bonded to the support.

For comparison, the reliant press machine “J
R-1000LTS "(Asahi Textile Machinery Co., Ltd., trade name) was heated at a temperature of 150 ° C. for 10 seconds to fix the deodorized powder granules, except that the conditions were the same as in the examples. Thus, a deodorizing filter medium according to a comparative example was produced.

Observation of these samples with an optical microscope revealed that the deodorized filter medium according to the above example had a resin aggregated portion at the portion where the web and the deodorized powder were fixed, as described as a feature of the present invention. More specifically, in the example, the apparent fiber density in a portion where the deodorized powdery material was not fixed was reduced due to the formation of the resin aggregated portion by heating. On the other hand, in the deodorizing filter medium according to the comparative example, before and after heating and fixing the deodorized powder granules, the hot-melt nonwoven fabric used becomes a film,
A structure in which the pressure loss increased was observed. Hereinafter, the measurement results of the pressure loss and the deodorizing efficiency according to these Examples and Comparative Examples will be described.

First, in measuring the pressure loss, according to a standard method, air was blown to each of the deodorizing filter media at a wind speed of 10 cm / sec, and a difference in pressure between the upstream and downstream of the filter media was determined. As a result, a pressure loss of 3 Pa was observed in the filter medium of the example, while a pressure loss of 5 Pa was observed in the comparative example. By applying the structure of the present invention, the pressure loss was reduced to 60%. It became clear what could be done.

The deodorization efficiency was measured using toluene as an odorant under the conditions of an initial concentration of 25 ppm and a surface wind speed of 14 cm / sec. In this measurement, one minute after the start of the measurement, the measurement condition was considered to have reached a steady state, and was set as the initial stage. Regarding the results, the difference between the initial concentration (upstream concentration) and the downstream concentration after passing through the filter medium was divided by the initial concentration and calculated as a percentage. As a result, after reaching the steady state, the efficiency after 10 minutes has passed
Compared to 80% in the example, 72% in the comparative example
Met. From these results, in the filter medium to which the present invention is applied,
Compared with the prior art, it has been found that it has excellent deodorizing efficiency and can realize low pressure loss as described above.

[0019]

As is clear from the above description, by applying the present invention, the deodorizing efficiency is high,
Moreover, an excellent deodorizing filter medium having a low pressure loss can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a part of a deodorizing filter medium for explaining the present invention.

FIG. 2 is a diagram illustrating a part of a deodorizing filter medium in a schematic plan view for explaining the present invention.

[Explanation of symbols]

11: Connecting part 13: Resin aggregation part 1
5: Web 17: Deodorized powder granules.

Claims (2)

[Claims] 1. A deodorizing method characterized in that a deodorizing powder is fixed to one surface of a web constituted by a connecting portion made of a hot-melt resin and a resin aggregation portion via the resin aggregation portion. Filter media. 2. The method according to claim 1, wherein the hot melt resin comprises a thermoplastic polyamide resin, a thermoplastic polyester resin, a thermoplastic polyurethane resin, a polyolefin resin, or an ethylene-vinyl acetate copolymer resin.
The deodorizing filter medium described in 1.