JP4845784B2 - Fluorescent nonwoven fabric for filters - Google Patents

Description

  The present invention relates to a fluorescent non-woven fabric for filters, and more particularly to a fluorescent non-woven fabric for filters containing a fluorescent agent suitable for judging the performance deterioration of filter materials used in non-woven fabric filters.

  It is extremely difficult to judge the performance degradation of the filter material actually used in a flat or pleated pleated nonwoven filter. The filter performance is clearly degraded at the time when the light comes to be understood under white light, and the load on the device used cannot be suppressed. For this reason, it has been desired that a decrease in filter performance can be determined and replacement can be performed, which leads to a reduction in load on the device used. However, no such method has been proposed at present.

  Therefore, the present inventor studied the measure and assumed that it can be determined at the start of the pressure increase as one of the determinations of the filter performance. As a result, it was difficult to judge the surface of the filter with white light, and it was difficult to make a judgment. It was found that can be visualized.

  The present invention is based on the fact that the filter containing the fluorescent agent-containing fiber and the binder brings about a good result in the determination of the deterioration of the filter performance in view of the above-mentioned knowledge, and adopts this to determine the deterioration of the filter performance at an early stage. The purpose is to contribute to the determination of replacement etc. and to reduce the load on the device used.

That is, the present invention suitable for the above-mentioned object contains a fluorescent agent having a fluorescent agent content of 0.1% by mass to 0.5% by mass in the short fibers constituting at least the surface of the short fiber nonwoven fabric in which one layer or multiple layers are laminated. A short fiber is mixed in a fiber mixing ratio of 15% by weight to 50% by weight, or a fluorescent agent-containing binder having a fluorescent agent content of 0.1% by mass to 0.5% by mass is formed on at least the surface layer of the nonwoven fabric. wherein the allowed to impart a range of ^{10g / m 2 ~100g / m 2} .

  The fluorescent agent-containing short fiber or the fluorescent agent-containing binder is not limited to the entire surface of the nonwoven fabric, and may be present only partially. A fluorescent dye or pigment is used as the fluorescent agent.

  By using the fluorescent nonwoven fabric of the present invention for a filter, it is possible to visually check the degree of filter dust clogging. As well as an effect of suppressing an increase in the load on the device in use due to a decrease in filter performance.

  Hereinafter, the specific aspect of this invention fluorescent nonwoven fabric is explained in full detail.

As described above, the nonwoven fabric of the present invention is constituted by at least the surface thereof having fluorescence performance. Here, as a specific configuration having fluorescence performance, a short fiber constituting at least a surface of a short fiber nonwoven fabric laminated with one layer or multiple layers is mixed with a fluorescent agent-containing short fiber or does not contain a fluorescent agent. Both of whether the binder containing the fluorescent agent is applied to at least the surface of the nonwoven fabric are included. Each will be described below.
(A) Configuration including fluorescent agent-containing short fibers In this configuration, the short fibers constituting the surface of the short fiber nonwoven fabric in which one layer or multiple layers are laminated include the fluorescent agent-containing short fibers. The blend ratio of the fluorescent agent-containing short fibers may be 15% by weight to 50% by weight, and if it is less than 15% by weight, the degree of light emission when irradiated with UV is poor and the difference in performance cannot be reduced. On the other hand, if the blending ratio exceeds 50% by weight, there is no need for excessive performance because the degree of light emission does not change even if the blending ratio is further increased when UV irradiation is performed.
(B) A configuration in which the short fiber constituting the nonwoven fabric surface does not contain a fluorescent agent-containing short fiber and the binder contains a fluorescent agent. For this configuration, 10 g is added to the surface layer of the short fiber nonwoven fabric in which one layer or multiple layers of the fluorescent agent-containing binder are laminated. / m ² formed by applying a range of to 100 g / m ^2. When the fluorescent agent-containing binder is less than 10 g / m ² on the nonwoven fabric surface layer, the degree of light emission when irradiated with UV is poor, and the difference in performance does not appear. Further, if the fluorescent agent-containing binder exceeds 100 g / m ² on the surface layer of the nonwoven fabric, it is not preferable because when UV irradiation is performed, even if it is increased to 100 g / m ² or more, the degree of light emission does not change and the excess performance is obtained.

In addition, as described above, the present invention mixes 15% to 50% by weight of the fluorescent agent-containing short fibers with the short fibers constituting the surface of the short fiber nonwoven fabric in which one layer or multiple layers are laminated, or uses fluorescent short fibers. While if not mixed fiber is achieved by applying a fluorescent agent-containing binder to the nonwoven surface layer in the range of ^{10g / m 2 ~100g / m 2} , the light emitting-containing fibers used in each of the foregoing cases, or the binder The amount of the fluorescent agent contained is preferably in the range of 0.1% by mass to 0.5% by mass. If the amount contained is less than 0.1% by mass, the degree of light emission is poor when UV irradiation is performed after processing into a filter nonwoven fabric, and it is difficult to discriminate the case of performance degradation.

  On the other hand, when the amount of the fluorescent agent contained in the fiber or the binder exceeds 0.5% by mass, even if it exceeds 0.5% by mass, the degree of light emission does not change and becomes an excessive amount, which is preferable in terms of cost. Absent. The fluorescent agent contained in the fiber or binder may be a fluorescent dye or pigment, and is not particularly limited as long as it is uniformly dissolved or dispersed in the thermoplastic resin or binder liquid constituting the fiber or binder. .

  Moreover, in the short fiber nonwoven fabric containing the fluorescent agent, the fluorescent agent-containing short fiber or binder is not limited to the whole nonwoven fabric layer, and may be a part, and the position where the fluorescent agent emits light is not particularly limited. Any configuration corresponding to each case may be used. When the filter nonwoven fabric is composed of a single layer or a multilayer web, a fluorescent agent may be present in the entire layer, but it is preferable and effective to be present at least on the outlet side of the filter. In particular, when a multi-layer web is used, it is preferable that the fluorescent material is contained in the exit side or in the vicinity of the exit to emit light, and it is not advantageous from the viewpoint of cost to add the fluorescent agent throughout the whole.

  Thus, by using the nonwoven fabric of the present invention, the state of dust can be easily determined by irradiating the filtered nonwoven fabric with UV light to visualize the state of spots on the nonwoven fabric surface. However, if dust accumulates on the surface, it is difficult to evaluate the entrance, but the exit state can be evaluated. That is, it is possible to determine the state of dust on the filter surface entering and exiting by the fluorescent layer.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.

Example 1 (fluorescent fiber on the middle / dense layer surface of two layers)
50% by weight of a fluorescent dye-containing polyester fiber (INVISTA, # 291) having a fineness of 2.2 dtex and a fiber length of 51 mm, and a polyester / low-melting polyester composite fiber having a fineness of 4.4 dtex and a fiber length of 51 mm (melting point of the low-melting polyester: 160 ° C.) 50% by weight of a middle layer fiber layer having a weight of 60 g / m ^{2 and} 50% by weight of a fluorescent dye-containing polyester fiber (INVISTA, # 121) having a fineness of 1.3 dtex and a fiber length of 51 mm; After laminating a dense fiber layer having a basis weight of 170 g / m ² consisting of 2 decitex, 50 mm% polyester / low melting point polyester composite fiber having a fiber length of 51 mm, a needle punching treatment is performed, and a pin tenter heat treatment machine at 210 ° C. For 47 seconds and contact the dense layer surface with a hot roll with a surface temperature of 215 ° C. The coarse layer surface side was a roll having a temperature of about room temperature, and the clearance between the two rolls was calendered with a clearance of 2.5 mm, followed by cooling to obtain a nonwoven fabric weight of 230 g / m ² .

Example 2 (Fluorescent fiber on two dense layers) 50/50
Fineness 6.6 decitex, polyester fiber (melting point: 260 ° C.) 50% by weight with a fiber length of 51 mm, fineness 4.4 decitex. Fiber layer for coarse layer having a basis weight of 60 g / m ² consisting of 50% by weight of a polyester / low melting point polyester composite fiber having a fiber length of 51 mm (melting point of the low melting point polyester: 160 ° C.), a fineness of 1.3 dtex, and a fiber length of 51 mm For dense layers having a weight per unit area of 170 g / m ² consisting of 50% by weight of a fluorescent dye-containing polyester fiber (INVISTA, # 121) and 50% by weight of a polyester / low melting point polyester composite fiber having a fineness of 2.2 dtex and a fiber length of 51 mm After laminating the fiber layer, it is subjected to needle punch treatment, heat treated for 47 seconds with a 210 ° C. pin tenter heat treatment machine, and the dense layer surface is brought into contact with a hot roll having a surface temperature of 215 ° C. The clearance between the two rolls is calendered with a clearance of 1.5 mm, cooled, and the nonwoven fabric weight is 230 g / m ² was obtained.

Example 3 (Coating with binder containing fluorescent dye on three dense layers)
50% by weight of a polyester fiber (melting point: 260 ° C.) having a fineness of 6.6 decitex and a fiber length of 51 mm, and a polyester / low-melting polyester composite fiber having a fineness of 4.4 decitex and a fiber length of 51 mm (melting point of the low-melting polyester: 160 ° C.) Fiber layer for coarse layer consisting of 50% by weight and having a basis weight of 60 g / m ² , polyester fiber having a fineness of 2.2 dtex and a fiber length of 51 mm, 50% by weight of polyester fiber, 4.4 dtex and a fiber length of 51 mm / low melting point A fiber layer for a middle layer consisting of 50% by weight of a polyester composite fiber, a fabric layer for a middle layer of 90 g / m ² , a polyester fiber having a fineness of 1.3 dtex and a fiber length of 51 mm, a polyester fiber having a fineness of 2.2 dtex and a fiber length of 51 mm basis weight weight 170 g / m ² of the dense layer fiber consisting of 50 wt% low melting polyester bicomponent fibers After laminating the layers, needle punching is performed, and heat treatment is performed for 47 seconds with a 210 ° C. pin tenter heat treatment machine, the dense layer surface is brought into contact with a hot roll having a surface temperature of 215 ° C., and the rough layer surface side is at a room temperature. The rolls were calendered with a clearance between the rolls of 2.5 mm, cooled to obtain a nonwoven fabric, and then a fluorescent content-containing acrylic binder (Ciba Specialty Chemicals Co., Ltd., trade name H-1-5) on the dense layer surface. , 0.1 mass%) resin was applied at 60 g / m ² and dried to obtain a nonwoven fabric having a basis weight of 380 g / m ² .

Comparative Example 1 (fluorescent fiber on the middle layer of 3 layers)
50% by weight of a polyester fiber (melting point: 260 ° C.) having a fineness of 6.6 decitex and a fiber length of 51 mm, and a polyester / low-melting polyester composite fiber having a fineness of 4.4 decitex and a fiber length of 51 mm (melting point of the low-melting polyester: 160 ° C.) A fiber layer for a coarse layer having a basis weight of 60 g / m ² consisting of 50% by weight, 50% by weight of a fluorescent dye-containing polyester fiber having a fineness of 2.2 dtex and a fiber length of 51 mm, a fineness of 4.4 dtex and a fiber length of 51 mm 90 g / m ² middle layer fiber layer comprising 50% by weight of polyester / low melting point polyester composite fiber, 50% by weight of polyester fiber having a fineness of 1.3 dtex and a fiber length of 51 mm, a fineness of 2.2 dtex, and fiber length 170 g of basis weight consisting of 50% by weight of 51 mm polyester / low melting point polyester composite fiber After laminating a fiber layer for dense layer of / m ² , it is subjected to needle punch treatment, heat treated for 47 seconds with a 210 ° C. pin tenter heat treatment machine, and the dense layer surface is contacted with a hot roll having a surface temperature of 215 ° C. The layer surface side was a roll having a temperature of about room temperature, and the clearance between both rolls was calendered with a clearance of 2.5 mm, followed by cooling to obtain a nonwoven fabric mass of 320 g / m ² .

Comparative Example 2 (two-layer coarse, dense)
50% by weight of a polyester fiber (melting point: 260 ° C.) having a fineness of 6.6 decitex and a fiber length of 51 mm, and a polyester / low-melting polyester composite fiber having a fineness of 4.4 decitex and a fiber length of 51 mm (melting point of the low-melting polyester: 160 ° C.) 50% by weight of the coarse layer fiber layer having a basis weight of 60 g / m ² , a fineness of 1.3 dtex and a fiber length of 51 mm of polyester fiber of 50 wt%, a fineness of 2.2 dtex and a fiber length of 51 mm of polyester / low After laminating a dense fiber layer having a basis weight of 170 g / m ² composed of 50% by weight of a melting point reester composite fiber, it was subjected to needle punching, heat-treated for 47 seconds with a 210 ° C. pin tenter heat treatment machine, and further the dense layer surface The roll is brought into contact with a hot roll having a surface temperature of 215 ° C., and the rough layer side is a roll having a temperature of about room temperature. The rear lance was calendered to 1.5 mm and cooled to obtain a nonwoven fabric weight per unit area of 230 g / m ² .

Comparative Example 3 (fluorescent fiber on two dense layers) 10/90
50% by weight of a polyester fiber (melting point: 260 ° C.) having a fineness of 6.6 decitex and a fiber length of 51 mm, and a polyester / low-melting polyester composite fiber having a fineness of 4.4 decitex and a fiber length of 51 mm (melting point of the low-melting polyester: 160 ° C.) A coarse fiber layer having a basis weight of 60 g / m ² comprising 50% by weight, a fluorescent dye-containing polyester fiber (INVISTA, # 121) having a fineness of 1.3 dtex and a fiber length of 51 mm, and a fineness of 2.2 After laminating a dense layer fiber layer having a basis weight of 170 g / m ² consisting of decitex and a polyester fiber having a fiber length of 51 mm / 90% by weight of a low-melting polyester composite fiber, a needle punching process is performed, and a 210 ° C. pin tenter heat treatment machine is used. Heat-treated for 47 seconds, and the dense layer surface was brought into contact with a hot roll having a surface temperature of 215 ° C. With a roll that is about the temperature. The clearance between both rolls was set to 1.5 mm, calendered, and cooled to obtain a nonwoven fabric weight of 230 g / m ² . Next, the nonwoven fabrics obtained in the above examples and comparative examples were used, and the surface emission state and the filtration state were evaluated, respectively. The results and overall evaluation are shown in Table 1. In the table, the basis weight and thickness were measured as follows, and the surface luminescence and the filtration state were evaluated based on the following methods, respectively.
(A) Mass per unit area: g / m ²
A size of 50 cm × 50 cm is cut out, the weight at that time is measured, and converted to a weight per 1 m ² .
(B) Thickness: mm
A size of 15 cm × 15 cm is cut out, an initial load of 0.05 g / cm ² is applied, the heights of the four corners are measured, and the average value is shown.
(C) Surface emission evaluation Irradiation device: Mambeth Spectra Light MODEL NO. SPL65B
(120V, 60Hz, 2000WATTS)
UV TOSHIBA FL20S / BLB
Judgment: A sample is placed in a Mumbeth Spectra light box and irradiated with UV to determine the light emission state of the surface. The surface is clearly lit by UV irradiation. ○
The surface is slightly darkened by UV irradiation. △
The surface does not emit light by UV irradiation. ×
(D) Evaluation of filtration state Sample adjustment: The dust collection performance test was performed based on the automotive air cleaner test method of JIS D1612. However, a disk filter medium having an effective area of 1000 cm ² was used as an element of the test air cleaner. The experimental conditions were such that the apparent air flow rate through the filter medium was 40 cm / sec, the dust concentration of the eight types of powders specified in JIS Z8901 was 1 g / m ^3, and sprayed to 0.5 mmAq for a filtration area of 1000 cm ² .

UV irradiation evaluation Irradiation device: Mambeth Spectra Light MODEL NO. SPL65B
(120V, 60Hz, 2000WATTS)
UV TOSHIBA FL20S / BLB
Judgment: A sample was put in a Mumbeth Spectra light box and irradiated with UV, and the degree of dust was judged by comparing it with white light before and after the test.
Although it was not visible with white light, the degree of contamination was revealed by UV irradiation. ○
Although it was not visible with white light, a slight degree of dirt was developed by UV irradiation. △
Although it was not visible with white light, no UV irradiation was visible. ×

上記の表より本発明の実施例に係る不織布は各比較例に係る不織布に比し、表面発光，濾過状態共に優れており、ＵＶ照射により汚れ具合の判定に頗る効果的であることが分かる。

From the above table, it can be seen that the nonwoven fabrics according to the examples of the present invention are superior to the nonwoven fabrics according to the comparative examples in terms of both surface emission and filtration, and are effective in determining the degree of contamination by UV irradiation.

Claims (3)

  Fluorescent agent-containing short fibers are mixed with the short fibers constituting at least the surface of the short fiber nonwoven fabric in which one layer or multiple layers are laminated, and the fluorescent agent content of the short fibers is 0.1% by mass to 0.5% by mass. %, And the mixing ratio of the fluorescent agent-containing short fibers is in the range of 15% by weight to 50% by weight. A fluorescent agent-containing binder 10g / m ² ~100g / m ² applied to it in a single layer or at least the surface layer of short fiber nonwoven fabric obtained by laminating a multilayer, fluorescent agent content of the fluorescent agent-containing binder is 0.1 wt% A fluorescent non-woven fabric for a filter, characterized by being -0.5% by mass.   The fluorescent nonwoven fabric for filters according to claim 1 or 2, wherein the fluorescent agent is a dye or a pigment.