JP2021167099A - Transpiration non-woven fabric - Google Patents

Abstract

To provide a transpiration non-woven fabric that has an excellent water absorption and contributes to miniaturization and high efficiency of a unit for a condensed water evaporator.SOLUTION: There is provided a transpiration non-woven fabric in which a surface material 2 containing glass fibers is arranged on both sides of a non-woven fabric 1 containing hydrophilic fibers and a heat-sealable resin.SELECTED DRAWING: Figure 1

Description

The present invention relates to a transpiration nonwoven fabric, and more particularly to a transpirationed nonwoven fabric which is excellent in mechanical properties such as water absorption and rigidity and is suitably used for applications such as a dew condensation water absorbing material, a transpiration plate, and a humidity control plate.

Transpirational non-woven fabrics having a function of absorbing water and evaporating (vaporizing) from the surface are conventionally known. Such a transpirational non-woven fabric can be used, for example, as a transpiration plate for discharging dew condensation water (drain) generated in a refrigerated / frozen showcase installed in a supermarket, a convenience store, or the like, or a dry state in a room when a heater is used. It is used in applications such as vaporization type humidifiers for relaxation.

In these uses, the transpirationable non-woven fabric absorbs drainage and humidifying water, for example, by arranging one end thereof in a drain tray or a humidifying water dish, or by supplying humidifying water from above. Moisture contained inside the evaporative non-woven fabric that has been absorbed is released from the surface of the evaporative non-woven fabric by evaporating (vaporizing). Evaporation (vaporization) is promoted by aeration. In this way, by using the transpirational non-woven fabric, it is possible to prevent the drain from overflowing in the saucer and to humidify the room.

Further, in order to achieve miniaturization and high efficiency of the unit for the condensed water evaporator, it is necessary to suppress the thickness of the transpirationable non-woven fabric and arrange it in the unit at narrow intervals in order to increase the surface area. However, when the transpiration non-woven fabric sucks up water, if the non-woven fabric is bent due to its weight, the air flow is bent or blocked, and the transpiration property is lowered. In addition, the non-woven fabric may be bent, which may cause the evaporation unit to be decomposed or damaged.

Therefore, the transpirationable non-woven fabric for use in these applications is required to have good water absorption and mechanical properties such as rigidity (morphological stability) that can maintain its morphology during use.

Therefore, in order to improve the rigidity of the transpired non-woven fabric, Patent Document 1 has a synthetic resin such as polyester laminated on both sides of the water-absorbent fibrous material as a shape-retaining layer. Further, Patent Document 2 and Patent Document 3 disclose a non-woven fabric containing inorganic fibers and a heat-sealing resin together with hydrophilic fibers to increase the rigidity of the non-woven fabric.

However, the transpirational non-woven fabrics disclosed in these patent documents have a problem that the morphological stability becomes insufficient when the paper density is lowered, the adjacent transpirational non-woven fabrics come into contact with each other to reduce the surface area, and the transpiration effect is lowered. was there.

Japanese Unexamined Patent Publication No. 2011-62816 Japanese Unexamined Patent Publication No. 2015-382258 Japanese Unexamined Patent Publication No. 2017-2439

Therefore, the present invention provides a transpiring non-woven fabric which has excellent water absorption and contributes to miniaturization and high efficiency of a unit for a condensed water evaporator.

One embodiment of the present invention is characterized in that surface materials containing glass fibers are arranged on both sides of a non-woven fabric containing hydrophilic fibers and a heat-sealing resin.

Further, in one embodiment, the surface material may be glass paper. Furthermore, in another embodiment, the content of the glass fiber in the surface material can be 70% by mass or more and 90% by mass or less.

In one embodiment, the paper density of the surface material may be 10 g / m ² or more and 100 g / m ² or less, and in another embodiment, the paper density of the evaporative non-woven fabric is 100 g / m ² or more and 600 g. It may be less than / m ^2.

Furthermore, one embodiment of the present invention relates to a unit for a condensed water evaporator, which is formed by fixing at least one end of a sheet made of these transpirational non-woven fabrics.

It is sectional drawing of one Embodiment of this invention.

One embodiment of the present invention will be described in detail with reference to FIG. In one embodiment of the present invention, the transpirationable nonwoven fabric includes a nonwoven fabric 1 and surface materials 2 arranged on both sides thereof.

(Non-woven fabric)
The non-woven fabric 1 contains hydrophilic fibers and a heat-sealing resin.

As the hydrophilic fiber used in the non-woven fabric 1, at least one fiber selected from natural fibers or chemical fibers can be used. Examples of natural fibers include pulp, hemp, cotton, silk, wool, mineral fibers and the like. Examples of chemical fibers include synthetic fibers made of cellulosic fibers, highly absorbent resin fibers (SAF), polyvinyl alcohol resin (PVA), and the like. Cellulose-based fibers are preferable.

The heat-sealing resin used in the non-woven fabric 1 is a binder resin that binds the constituent components. The heat-sealing resin may be in the form of fibers or particles. The heat-sealing resin is preferably fibrous from the viewpoint of higher strength. The heat-sealing resin may be in the form of a shortcut fiber, for example. Two or more of these fibers may be used in combination.

Examples of the heat-sealing resin used for the non-woven fabric 1 include polyethylene (PE), polypropylene, polyethylene terephthalate (PET), ethylene-vinyl acetate copolymer (EVA), polyamide, polylactic acid, and polybutylene succinate. ..

The heat-sealing resin may be a composite of two or more kinds of resins. For example, it has a core-sheath fiber composed of a core portion and a sheath portion, a side-by-side fiber in which one half and the other half in a cross section perpendicular to the longitudinal direction are made of different resins, and a core and shell made of different resins. Examples include core-shell particles. Above all, when it is desired to exhibit the performance of the heat-sealing resin while improving the rigidity of the non-woven fabric, the core-sheath fiber is preferable.

The core-sheath fiber includes, for example, a PP / PE composite core having a core portion made of polypropylene fiber (melting point 160 ° C.) and a sheath portion made of polyethylene (melting point 130 ° C.) formed on the outer periphery of the core portion. Sheath fiber can be mentioned. As other core-sheath fibers, PP / EVA composite core-sheath fiber, PET / low melting point PET composite core-sheath fiber, high-density polyethylene / low-density polyethylene composite core-sheath fiber, PET / PE composite core-sheath fiber, polyamide / Examples thereof include low melting point polyamide composite core sheath fiber, polylactic acid / low melting point polylactic acid composite core sheath fiber, polylactic acid / polybutylene succinate composite core sheath fiber and the like. Among the core-sheath fibers, composite core-sheath fibers having a sheath portion made of polyethylene, such as PP / PE composite core-sheath fiber, PET / PE composite core-sheath fiber, and PE / PE composite core-sheath fiber, are preferable.

The non-woven fabric 1 can be formed by an existing method such as an airlaid method, a spunbond method, a thermal bond method, a spunlace method, a melt blow method, a needle punch method, or the like.

In the non-woven fabric 1, the hydrophilic fibers and the heat-sealing resin can be mixed in an arbitrary ratio as long as they have the desired hydrophilicity and rigidity. Preferably, the non-woven fabric 1 contains less than 65% by mass of hydrophilic fibers and 10% by mass or more of a heat-sealing resin. More preferably, the hydrophilic fiber content is less than 60% by mass, and the heat-sealing resin is contained in an amount of 20% by mass or more.

(Surface material)
The surface material 2 contains glass fibers, and is preferably glass paper.

Glass paper is formed by papermaking glass fibers together with a binder. The content of the glass fiber in the surface material 2 is 70% by mass or more and 90% by mass or less. Preferably, it is 80% by mass or more and 90% by mass or less.

As the glass fiber, for example, any glass fiber such as E glass, C glass, S glass, D glass, AR glass and the like can be used, but E glass can be preferably used from the viewpoint of cost. The fiber diameter of the glass fiber is preferably 6 to 20 μm, and flat glass such as an ellipse or a rectangle can be used in addition to the circular cross-sectional shape. The glass fiber is cut to a predetermined length and used as the shape of a glass chopped strand.

The binder content of the surface material 2 is 5% by mass or more and 30% by mass or less. Preferably, it is 10% by mass or more and 30% by mass or less. As the binder used for the surface material 2, the above-mentioned heat-sealing resin can be used.

In one embodiment, the glass paper can be produced by various methods. That is, either a wet method or a dry method may be used. Examples of the wet method include a method in which water-dispersible glass fiber chopped strands are dispersed in water in which a dispersant is dissolved, then paper is made with a paper machine and dried with a hot air dryer, a drum dryer or the like.

The rice basis weight of the surface material 2 is 10 g / m ² or more and 100 g / m ² or less. Preferably, it is 20 g / m ² or more and 100 g / m ² or less. When the rice basis weight is 10 g / m ² or less, the rigidity and softness of the surface material 2 decreases. Deflection transpiration nonwoven basis weight of the surface material 2 is obtained larger but is unlikely to occur, if the basis weight amount is more than 100 g / m ^2, since the basis weight percentage of the total transpiration nonwoven fabric becomes too large, The suction performance and evaporation performance may deteriorate.

(Transpirational non-woven fabric)
In one embodiment, the transpiring non-woven fabric is a laminate in which the surface materials 2 are arranged on both sides of the non-woven fabric 1. For the laminated body, for example, the non-woven fabric 1 and the surface material 2 may be separately manufactured and bonded with an adhesive or the like to be manufactured. Further, the laminated body may be manufactured while sequentially forming each layer or a part of the layers. For example, using the airlaid method, the material of the nonwoven fabric 1 may be sprayed on the surface material 2, further covered with the surface material 2 and heat-sealed to form a laminate at the same time as producing the nonwoven fabric 1. ..

In one embodiment, the materials (each layer) in the laminate are joined and fixed by an adhesive component. The adhesive component is not particularly limited as long as the materials can be adhered to each other. For example, a commercially available adhesive (particularly a hot melt adhesive) may be appropriately selected depending on the materials of the nonwoven fabric 1 and the surface material 2. As the hot melt adhesive, either a liquid type or a solid type can be used. For example, a solid hot melt adhesive formed in a spider web shape (net shape) is interposed between each material and heat-pressed to preferably bond the adhesive. Further, the nonwoven fabric 1 and the surface material 2 may be adhered to each other by the heat-sealing resin contained in the nonwoven fabric 1.

The obtained transpirational non-woven fabric preferably has a paper ^{density of 100 g / m 2} or more and 600 g / m ² or less.

(Moisture absorbing / releasing material)
The use of the material of the present invention is not limited as long as it is used for moisture absorption and desorption, and can be widely used for applications where it is necessary to reversibly absorb and release moisture. That is, it can be used for the same purposes as the conventional moisture absorbing / releasing sheet. For example, it can be used for various devices / members (humidifiers, heat exchangers, daily necessities, home appliances, etc.) as vaporization filters, air cooling materials, dehumidifying materials, humidity control materials, etc., as well as for building materials, agriculture, etc. Can also be used as.

In particular, when used in a unit for a condensed water evaporator such as a humidifier, the transpirationable non-woven fabric is used alone or at intervals, and its end is fixed in a container containing condensed water. You may.

(Manufacture of transpirationable non-woven fabric using airlaid method)
Using the sheet shown in Table 1 as the surface material 2, a transpirationable nonwoven fabric was produced as follows by the airlaid method.

By the first carrier sheet supply means, the surface material 2 was fed out as the first carrier sheet on the air-permeable endless belt mounted on the conveyor and running.

While sucking the air-permeable endless belt with a suction box, polyethylene (PE) powder is ^{sprayed on the first carrier sheet so as to be 5 g / m 2,} and hydrophilic fibers (30%) and heat fusion are performed on the polyethylene (PE) powder at a rate of 5 g / m 2. A mixture of adhesive fibers (70%) was supplied from the web raw material supply means together with an air flow, and the web raw material A was dropped and deposited so that ^{the basis weight of the air-laid web portion was 260 g / m 2.}

Further, polyethylene (PE) powder is ^{sprayed on it so as to be 5 g / m 2} , and the same surface material 2 used for the first carrier sheet is laminated as a second carrier sheet to form a laminated body. Got

The obtained laminate was passed through a box-type dryer of a hot air circulation conveyor oven type and treated with hot air at 150 ° C. to obtain a transpirationable non-woven fabric.

A. Rigidity / softness, tensile strength and tensile elongation The transpirational non-woven fabrics obtained in Examples 1 to 3 and Comparative Examples 1 to 5 based on JIS L1913: 2010 (general non-woven fabric test method). , And tensile elongation were measured, respectively. The measurement results are shown in Table 2.

B. Rigidity The following tests were performed on the transpirationable nonwoven fabrics obtained in Examples 1 to 3 and Comparative Examples 1 to 5.
(Dry stiffness)
The obtained evaporative non-woven fabric was cut into 25 mm × 70 mm, and a numerical value at a bending angle of 7.5 ° was read using a tabor tester to measure Dry rigidity. The results are shown in Table 2.
(Wet stiffness)
The obtained evaporative non-woven fabric was cut into 25 mm × 70 mm, immersed in water for 1 minute to wet the whole, and then water droplets on the surface were wiped off and measured in the same manner as Dry rigidity to measure Wet rigidity. The results are shown in Table 2.
(Deformation test)
The obtained evaporative non-woven fabric was cut into 50 mm × 300 mm, and water was poured into a vat having an inner size of 276 mm × 211 mm × H35 mm to a bulkiness of 25 mm. The sample piece was placed so as to lean against the edge on the short side of the vat, and the sample was left to stand for 72 hours under the condition of 40 ° C. and 80% RH while the end of the sample was immersed in water. After drying, the sample piece was placed on a horizontal table, and the distance from the maximum point of the curved portion to the table surface was measured. The results are shown in Table 2.

C. Water Absorption The following water absorption tests were carried out for Examples 1 to 3 and Comparative Examples 1 and 3.
(Water absorption)
The obtained evaporative non-woven fabric was cut into 20 mm × 150 mm, immersed in water for 1 minute, and then the increased weight was measured. The results are shown in Table 3.
(Song distance)
The obtained evaporative non-woven fabric is cut into 20 mm × 150 mm, immersed in water for 1 minute, and then a weight is placed on a point 20 mm in the longitudinal direction from the end of the sample piece, and the rest is on the table so as to pop out from the table. A sample piece was placed in. The difference between the height of the end opposite to the end on which the weight is placed and the height of the sample on the table was measured, and this was defined as the bending distance (x). The results are shown in Table 3.

By sandwiching the non-woven fabric 1 between the surface materials 2 containing glass fibers, the evaporable non-woven fabric obtained in this example can exhibit thinness and high rigidity while maintaining high water absorption, and is deformed even during water absorption. Was few.

As described above, the present invention should be construed only from the matters described in the claims, and even in the above-described embodiments, all the changes and modifications included in the concept of the present invention are not described. Is possible. That is, all the matters in the above-described embodiment are not intended to limit the present invention, and may be arbitrarily changed according to the use and purpose thereof, including all configurations not directly related to the present invention. It is a thing.

1 Non-woven fabric 2 Surface material

Claims (6)

A transpiring non-woven fabric characterized in that surface materials containing glass fibers are arranged on both sides of the non-woven fabric containing hydrophilic fibers and a heat-sealing resin. The transpirationable nonwoven fabric according to claim 1, wherein the surface material is glass paper. The transpirationable nonwoven fabric according to claim 1 or 2, wherein the content of the glass fiber in the surface material is 70% by mass or more and 90% by mass or less. The transpirationable nonwoven fabric according to any one of claims 1 to 3, wherein the surface material has a paper density of 10 g / m ² or more and 100 g / m ^{2 or less.} The transpirationable nonwoven fabric according to any one of claims 1 to 3, wherein the transpirational nonwoven fabric has a paper density of 100 g / m ² or more and 600 g / m ^{2 or less.} A unit for a condensed water evaporator, wherein at least one end of a sheet made of the transpirational nonwoven fabric according to any one of claims 1 to 5 is fixed.

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