JP2021152230A - Total heat exchanging device paper, and total heat exchanging device - Google Patents

Abstract

To provide total heat exchanging device paper of excellent strength and an excellent shielding performance, for use in a total heat exchanger, and to provide a total heat exchanging device of an improved heat exchanging capability.SOLUTION: The total heat exchanging device paper made from a base material sheet containing natural pulp, is characterized in that the base material sheet contains natural pulp of a length-weighted mean fiber length of 0.7 to 1.7 mm, the natural pulp has the maximum frequency peak between 0.5 to 1.5 mm in its fiber-length histogram, the content of a fiber having a fiber length of 1.0 mm or longer is not less than 25.0%, and the base material sheet further contains a water soluble polyol selected from the group consisting of a polyether-polyol, a polyester-polyol and a polymer-polyol.SELECTED DRAWING: None

Description

The present invention is installed in a total heat exchanger that supplies fresh outside air to the room and discharges dirty air in the room in order to maintain a comfortable space in buildings, offices, stores, residences, etc. The present invention relates to total heat exchange element paper used for a total heat exchange element that exchanges sensible heat (temperature) and latent heat (humidity) at the same time.

In indoor air conditioning, as a ventilation method with excellent cooling and heating efficiency, exchange of humidity (latent heat) as well as temperature (sensible heat) between the air supply that supplies fresh outside air and the exhaust flow that discharges dirty air in the room. It is well known that total heat exchange can be performed at the same time.

In the total heat exchange element that performs total heat exchange, the supply airflow and the exhaust flow are formed in independent flow paths with the total heat exchange element paper sandwiched between them, and total heat exchange is performed between them. If the room is ventilated with a total heat exchanger equipped with a total heat exchange element, the cooling and heating efficiency can be greatly improved.

There are two types of total heat exchange elements, a orthogonal flow type and a countercurrent type, which are manufactured by processing total heat exchange element paper. Both are manufactured using a dedicated machine, but especially in the case of the countercurrent type, the process of attaching a resin frame to secure the flow path for passing indoor and outdoor air to the total heat exchange element paper is be. Generally, from the viewpoint of work efficiency, an injection molding machine is used to manufacture the resin frame. At this time, if the strength of the total heat exchange element paper is insufficient, the pressure of the injected resin causes the total heat exchange element paper. Is torn and does not function at all as a total heat exchange element.

In addition, since the conventional total heat exchange element paper uses a porous material, it also has air permeability of a dirty gas component such as carbon dioxide, and supplies air when exchanging total heat. And the exhaust are mixed inside the total heat exchange element, which has the disadvantage of reducing the efficiency of ventilation. This mixture of air supply and exhaust is a fatal defect for the total heat exchanger. In a total enthalpy heat exchanger in which air supply and exhaust are mixed, it may be evaluated that the air inside and outside the room is not exchanged while being recovered by energy, but simply agitating the dirty air in the room. In this way, if the indoor and outdoor air seems to be mixed, the purpose of ventilation cannot be achieved and the total heat exchanger cannot function at all.

For this reason, a total heat exchange element paper having excellent strength so as not to be torn when manufacturing a total heat exchange element and excellent shielding property so as not to mix air supply and exhaust is required. ing. In response to such demands, binders and melts are applied to the surface of a sheet base material of a non-woven fabric or woven cloth having a thickness of 0.1 to 1.0 mm and made of glass fibers, synthetic fibers or natural fibers having a fiber diameter of 0.3 to 50 μm. A sheet member (Patent Document 1) is disclosed in which an adhesive medium of fibers or adhesive powder is attached, and a thin layer of ultrafine fibers having a fiber diameter of 0.01 to 0.5 μm is layered on the adhesive medium and dried and fixed to be integrated. ing. However, although the strength of the sheet base material can be maintained, there is a problem in terms of economy, and no effect is observed in terms of shielding property.

Further, the fiber substrate is parchmenting, and a hygroscopic agent contained in said fiber substrate, and the moisture vapor permeable sheet moisture permeability is 1000 g / m 2 ^· 24 hr or more (Patent Document 2) discloses Has been done. However, there was room for improvement in the strength and shielding property of the fiber base material.

Further, there is disclosed a total heat exchange element paper (Patent Document 3) made of paper containing natural pulp beaten to 150 ml or less in a modified Canadian filtrate. However, although there is no problem with the shielding property, it is not possible to obtain sufficient strength of the total heat exchange element paper.

Further, it is made of a paper base material mainly composed of pulp, and the base paper for a total heat exchanger element contains 10 to 25% by mass of calcium chloride and has a hygroscopicity of 15 to 30% (patented). Document 4) is disclosed. However, there was room for improvement in order to achieve both strength and shielding properties.

Further, a total heat exchange element in which a base paper made of wood pulp in which 100 parts by mass of wood pulp is 40 parts by mass or more and the degree of beating at shopper freedom is 40 ° SR or more is impregnated with a hygroscopic agent and a flameproofing agent. a paper, with a moisture permeability by moisture permeability test according to JIS Z-0208 of該全heat exchange element sheets 6,000g ^{/ m} 2 · 24 hours or more, carbide by flame test according to JIS Z-2150 Total heat exchange element paper (patented) having a length of 10 cm or less, an air permeability according to a JIS P-8117 air permeability test of 500 seconds / 100 ml or more, and a carbon dioxide transfer rate of 1% or less. Document 5) is disclosed. However, there was room for improvement in achieving both strength and shielding properties with this paper.

Furthermore, improving the heat exchange performance of the total heat exchanger as a whole is important from the viewpoint of energy saving and cost reduction of the system, and it is also possible to improve the heat exchange performance of the total heat exchange element used in the total heat exchanger. , Equally important. On the other hand, a hygroscopic agent is applied, and the air permeability according to JIS P8117 is 0.13 μm / (Pa · S) or less, and the permeation under the conditions of 23 ° C. and 50% relative humidity according to JIS Z0208. humidity is not less 300 g ^/ m 2 · 24h or more, the ratio of machine direction orientation strength / lateral orientation strength of the sheet is 1.0 to 1.8, more preferably longitudinal orientation strength / lateral A total heat exchange element paper characterized in that the ratio of orientation strength is 1.0 to 1.5 has been proposed (for example, Patent Document 6). The total heat exchange element made of this total heat exchange element paper has good heat exchange performance, but it is more preferable that the heat exchange performance is further improved.

In addition, a binder is mixed with a fibrous material containing ceramic fibers as a main component, and a flat plate and a corrugated plate of the paper leaf-like material obtained by papermaking are alternately polymerized to polymerize heat exchange between the paper leaves. A total heat exchange element having a path formed has been proposed (for example, Patent Document 7). This total heat exchange element is good because the heat exchange effect performance is improved. be.

Further, it has a fiber base material mainly composed of cellulose fibers and a temperature control agent containing a latent heat storage component having a melting point of 10 to 35 ° C. dispersed in the fiber base material, and the content of the temperature control agent is transparent. A breathable sheet has been proposed, characterized in that it is 1.0 to 8.0% by mass and has a density of 0.5 to 1.5 g / cm ^{3 with respect to the total mass of the wet sheet (eg,).} Patent Document 8). The moisture permeable sheet and the total heat exchanger element using the moisture permeable sheet as a partition plate have excellent heat transfer properties, moisture permeability and gas barrier properties, and have a certain effect that dew condensation is less likely to occur, but the moisture permeability is improved. It is more preferable that there is an up.

Japanese Unexamined Patent Publication No. 2011-237157 Japanese Unexamined Patent Publication No. 2016-108704 International Publication No. 2002/099193 Pamphlet Japanese Unexamined Patent Publication No. 2007-119969 Japanese Unexamined Patent Publication No. 2005-325473 Japanese Unexamined Patent Publication No. 2015-59286 Japanese Unexamined Patent Publication No. 52-127663 Japanese Unexamined Patent Publication No. 2017-179613

An object of the present invention is to provide a total heat exchange element paper for a total heat exchanger having excellent strength and shielding properties. Another object of the present invention is to provide a total heat exchange element having improved heat exchange performance.

The problem according to the present invention can be solved by the following means.
<1> A total heat exchange element paper made of a base sheet containing natural pulp, wherein the base sheet contains natural pulp having a length-weighted average fiber length of 0.7 to 1.7 mm. In the fiber length histogram, natural pulp has a maximum frequency peak between 0.5 and 1.5 mm, and the proportion of fibers having a fiber length of 1.0 mm or more is 25.0% or more, and is a base sheet. However, the total heat exchange element paper further contains a water-soluble polyol selected from the group of polyether polyols, polyester polyols and polymer polyols.

<2> The total heat exchange element paper according to <1> above, wherein the natural pulp has a peak between 0.0 and 0.5 mm in addition to the maximum frequency peak in the fiber length histogram.

<3> A total heat exchange element formed by using the total heat exchange element paper according to the above <1> or <2>.

According to the present invention, it is possible to provide a total heat exchange element paper for a total heat exchanger having excellent strength and shielding properties. Further, it is possible to provide a total heat exchange element having improved heat exchange performance.

It is the schematic of the orthogonal flow type total heat exchange element. This is an example of a fiber length histogram of natural pulp having a maximum frequency peak between 0.5 and 1.5 mm and a peak between 0.0 and 0.5 mm in addition to the maximum frequency peak.

Hereinafter, the total heat exchange element paper of the present invention will be described in detail.

The total heat exchange element paper of the present invention comprises a base sheet containing natural pulp. The substrate sheet contains natural pulp having a length-weighted average fiber length of 0.7-1.7 mm, which is most frequently between 0.5-1.5 mm in the fiber length histogram. The proportion of fibers having a peak and a fiber length of 1.0 mm or more is 25.0% or more, and the base sheet is a water-soluble material selected from the group of polyether polyols, polyester polyols and polymer polyols. It is a total heat exchange element paper characterized by further containing a polyol.

The base sheet in the present invention is preferably a sheet produced by a wet papermaking method using natural pulp as a raw material. As natural pulp, broad-leaved bleached kraft pulp (abbreviation: LBKP, English notation: Hardwood Bleached Kraft Pulp), coniferous bleached kraft pulp (abbreviation: NBKP, English notation: Softwood Bleached Craft Pulp), broad-leaved bleached kraft pulp , English notation: Hardwood Bleached Sulfite Pulp), coniferous bleached sulphite pulp (abbreviation: NBSP, English notation: Softwood Bleached Sulfite Pulp), broadleaf tree unbleached kraft pulp (abbreviation: LUKP It is preferable to use wood pulp fibers such as bleached kraft pulp (abbreviation: NUKP, English notation: Softwood Unbleached Craft Pulp) alone or in combination of two or more. As other fibers, the base sheet contains plant fibers such as cotton, cotton linter, hemp, bamboo, sugar cane, corn, and kenaf; animal fibers such as wool and silk; and regenerated cellulose fibers such as rayon, cupra, and lyocell. It can also be used in combination of two or more.

In the present invention, the length-weighted average fiber length of natural pulp is 0.7 to 1.7 mm. Further, as shown in FIG. 2, in the fiber length histogram of natural pulp, the proportion of fibers having a maximum frequency peak between 0.5 and 1.5 mm and having a fiber length of 1.0 mm or more is 25. It is 0% or more. Total heat exchange element In the process of producing a total heat exchange element from paper, the length-weighted average fiber length of natural pulp is 0.7 to 1.7 mm, and by entwining fibers of 1.0 mm or more, The strength of the total heat exchange element paper is increased, and the shielding property is also improved. The maximum frequency peak is more preferably between 0.7 and 1.2 mm. The proportion of fibers having a fiber length of 1.0 mm or more is more preferably 30.0% or more, and even more preferably 35.0% or more. The proportion of fibers having a fiber length of 1.0 mm or more is preferably 60.0% or less.

Further, in the total heat exchange element paper in which natural pulp has a peak (second peak) between 0.0 and 0.5 mm in addition to the maximum frequency peak in the fiber length histogram, finer fibers are inter-fibers. By closing the gap, the strength is maintained, it is difficult for air supply and exhaust to mix, and it has better shielding properties.

The fiber length and fiber length distribution histogram of the natural pulp of the present invention is based on JIS P8226: 2006 (polarization method) "Pulp-Fiber length measurement method by optical automatic analysis method", OpTest Equipment Inc. The measurement was performed using a fiber quality analyzer manufactured by Canada.

The "fiber length", "average fiber length" and "fiber length distribution" in the present invention are "length-weighted fiber length", "length-weighted average fiber length" and "length-weighted" measured and calculated according to the above. It means "fiber length distribution". Further, the "ratio of fibers having a fiber length of 1.0 mm or more" means the "ratio of fibers having a fiber length of 1.0 mm or more", and in the "length-weighted fiber length distribution" measured and calculated according to the above. It means the numerical value obtained from the "ratio of fibers of 1.0 mm or more".

Natural pulp is a beater, PFI mill, single disc refiner (SDR), double disc refiner (DDR), ball mill, dyno mill, grinder, rotary blade homogenizer that applies shearing force by high speed rotary blade, cylindrical shape that rotates at high speed. A double-cylindrical high-speed homogenizer that produces shearing force between the inner and outer blades of the It is applied to a high-pressure homogenizer or the like that applies shearing force and cutting force to the fiber by giving it to pass through a small-diameter orifice to increase the speed, and by colliding this to make it suddenly decelerate, and it is prepared to the above-mentioned desired fiber length distribution and the like. NS. Of these, the refiner is particularly preferable. By adjusting these beating, the type of dispersion equipment, and the processing conditions (fiber concentration, temperature, pressure, rotation speed, shape of the refiner blade, gap between the refiner plates, number of treatments), the fiber length distribution of the target natural pulp, etc. Can be achieved.

The base sheet is provided with, for example, heavy calcium carbonate, light calcium carbonate, kaolin, talc, clay, titanium dioxide, aluminum hydroxide, silica, alumina, and organic pigments in order to obtain the required density, smoothness, and moisturizing properties. Various fillers such as, adhesives, sizing agents, fixing agents, yield agents, and various compounding agents such as paper strength enhancers can be appropriately contained.

Examples of the method for producing the base sheet include a wet paper making method in which natural pulp is formed into a sheet using a general long net paper machine, a circular net paper machine, or the like.

The base sheet may be surface-sized with a size press, roll coater, or the like installed in a paper machine in order to obtain the required density, smoothness, air permeability, and strength. As a component of the surface size press liquid, various synthetic binders such as polyvinyl alcohol can be appropriately used.

The substrate sheet may be calendared to obtain the required density, smoothness, air permeability and strength. As the calendar device, a device having one or more combination rolls selected from the group consisting of hard rolls, elastic rolls, and a combination of hard rolls and elastic rolls is preferably used. Specifically, a machine calendar, a soft nip calendar, a super calendar, a multi-stage calendar, a multi-nip calendar, or the like can be used.

In the total heat exchange element paper of the present invention, the base sheet contains a water-soluble polyol. By containing the water-soluble polyol, the heat exchange performance of the total heat exchange element can be improved.

The water-soluble polyol in the present invention is selected from the group of polyether polyols, polyester polyols and polymer polyols. One type may be selected, or two or more types may be selected. The polyether polyol is a polyol produced by addition polymerization of a low molecular weight compound having two or more hydroxyl groups in the molecule such as glycol, glycerin, sorbitol, and sugar, and an alkylene oxide such as propylene oxide and ethylene oxide. The polyester polyol is a polyol obtained by condensing a dibasic acid such as adipic acid with a polyhydric alcohol such as ethylene glycol and having a hydroxyl group at the end. The polymer polyol is a polymer polyol in which polystyrene or polyacrylonitrile is dispersed in the polyol. The water solubility of the water-soluble polyol of the present invention means that 5 g or more is dissolved in 100 g of water at 20 ° C. In the present specification, "a water-soluble polyol selected from the group of polyether polyols, polyester polyols and polymer polyols" may be abbreviated as "water-soluble polyol".

When the base sheet contains the water-soluble polyol, the moisture absorbed on the surface of the total heat exchange element paper via the hydroxyl groups contained in the water-soluble polyol is promoted to move in the thickness direction of the paper. It is presumed that this will improve the heat exchange performance of the total heat exchange element. The inclusion of the water-insoluble polyol in the base sheet also improves the heat exchange performance of the total heat exchange element in the same manner as the water-soluble polyol, but the base sheet is water-insoluble and water-insoluble. The inclusion of the polyol makes the coating process complicated, which is not preferable.

In the total heat exchange element sheets of the present invention, the content of the water-soluble polyol is preferably 0.3 to 10 / ^{m 2,} and more preferably 0.5 to 5 g / ^{m 2.} If the content is ^{less than 0.3 g / m 2} , the desired effect of improving heat exchange performance may not be obtained, while if the content exceeds 10 g / m ² , the effect will level off and will not be achieved. It is an economy.

A flame retardant can be attached to the total heat exchange paper for the purpose of imparting flame retardancy. Examples of the flame retardant include an inorganic flame retardant, an inorganic phosphorus compound, a nitrogen-containing compound, a chlorine compound, and a bromine compound. For example, a mixture of borosand and boric acid, aluminum hydroxide, antimony trioxide, ammonium phosphate, ammonium polyphosphate, ammonium sulfamate, guanidine sulfamate, guanidine phosphate, phosphate amide, chlorinated polyolefin, ammonium bromide, Examples thereof include a flame retardant that can be dispersed in an aqueous solution such as a non-ether type polybromocyclic compound or water. As for the level of flame retardancy, it is preferable that the carbonization length measured by JIS A 1322: 1966 is less than 10 cm. The content of the flame retardant is not particularly limited, depending on the flame retardant to be used is ^{preferably 5g / m 2 ~10g / m 2} . More than 10 g / m ² may be attached, but the effect will level off.

The total heat exchange element paper may contain an antifungal agent for the purpose of imparting antifungal properties. As the fungicide, those commercially available as fungicides can be generally used. For example, organic nitrogen compounds, sulfur compounds, organic acid esters, organic iodine imidazole compounds, benzazole compounds and the like can be mentioned. As the level of antifungal property, it is preferable that the growth of hyphae measured by JIS Z 2911: 2010 is not observed. The content of antifungal agent is preferably ^{0.5g / m 2 ~5g / m 2} . More than 5 g / m ² may be attached, but the effect will level off.

The total heat exchange element paper may contain a hygroscopic agent for the purpose of improving the humidity exchange efficiency. Examples of the hygroscopic agent include inorganic acid salts, organic acid salts, inorganic fillers, ureas, and moisture-absorbing (water-absorbing) polymers. For example, the inorganic acid salt includes lithium chloride, calcium chloride, magnesium chloride and the like. Examples of the organic acid salt include sodium lactate, calcium lactate, sodium pyrrolidone carboxylate and the like. Examples of the inorganic filler include aluminum hydroxide, calcium carbonate, aluminum silicate, magnesium silicate, talc, clay, zeolite, diatomaceous earth, sepiolite, silica gel, and activated charcoal. Examples of ureas include urea and hydroxyethyl urea. Examples of the moisture-absorbing (water-absorbing) polymer include polyaspartic acid, polyacrylic acid, polyglutamic acid, polylysine, alginic acid, carboxymethyl cellulose, hydroxyalkyl cellulose and salts or cross-linked products thereof, hyaluronic acid and its cross-linked product, collagen, acrylic. Nitrile-based polymer saponified product, vinyl acetate / acrylate copolymer saponified product, acrylate / acrylamide copolymer, polyvinyl alcohol / maleic anhydride copolymer, polyethylene oxide-based, isobutylene-maleic anhydride copolymer And so on. The hygroscopic agent is used by selecting the type and the amount of adhesion according to the target moisture permeability. From the viewpoint of cost and moisture permeability, it is preferable to use one or more hygroscopic agents selected from the group of calcium chloride, lithium chloride and magnesium chloride. A particularly preferred hygroscopic agent is calcium chloride. Calcium chloride may be used in combination with other hygroscopic agents.

The amount of the hygroscopic agent attached is not particularly limited. Depending on the type of desiccant to be used, JIS Z 0208: using the evaluation method 1976, 23 ° C., the moisture permeability measured at 50% relative humidity is not less 300g ^/ m 2 · 24h or more preferable. Within this range, a total heat exchange element having excellent wet heat exchange performance can be obtained. The adhesion amount of the moisture absorbent, depending on the type of desiccant to be used, sometimes level off heat and moisture exchanging performance from some adhesion amount is preferably ^{3g / m 2 ~15g / m 2} , more preferably ^{4g / m 2 ~10g / m 2} . Preferably ^{300g / m 2 · 24h~1500g / m} 2 · 24h as moisture ^{permeability,} the range of ^{400g / m 2 · 24h~1000g / m} 2 · 24h , more preferred.

The method for containing a chemical such as a water-soluble polyol, a flame retardant, a fungicide, and a hygroscopic agent in the total heat exchange element paper is particularly limited as long as the chemical can be contained in the base sheet as uniformly as possible. There is no. Natural pulp and chemicals can be mixed to produce a base sheet, or a solution or dispersion containing the chemicals can be applied to the sheet containing natural pulp by a method such as coating, impregnation or spraying to provide a solvent. And a method of removing the dispersion medium by a method such as drying and incorporating the drug into the base sheet is exemplified.

Binders can also be used when containing the drug. The binder is not particularly limited, but for example, polyvinyl alcohol-based, (meth) acrylic acid resin-based, aromatic vinyl compound resin-based, styrene-butadiene rubber-based, vinyl acetate resin-based, ethylene-vinyl acetate copolymer resin-based, Examples thereof include binders such as silicon resin-based and fluorine-based resins. Of these, a water-soluble binder is particularly preferable.

The total heat exchange element paper is not particularly limited in terms of basis weight, thickness, density, etc., but from the viewpoint of heat exchange performance, it is preferable that the basis weight is low, the thickness is thin, and the density is high. The basis weight is preferably from 20 to 80 g / ^{m 2,} more preferably 30 to 60 g / ^{m 2,} more preferably 40 to 50 g / ^{m 2.} The thickness is preferably 20 to 80 μm, more preferably 30 to 60 μm, and even more preferably 40 to 50 μm. Density is preferably 0.6 to 1.2 g / cm ^3, more preferably 0.7 to 1.2 g / cm ^3, more preferably 0.8~1.1g / cm ^3.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the Examples. Unless otherwise specified, "%" and "parts" in the examples represent "mass%" and "parts by mass", respectively.

[Water drainage degree]
As a method for measuring the degree of drainage, the measurement was performed in accordance with the Canadian standard drainage test method of JIS P 811-2: 2012. However, if the natural pulp is too fine to be measured by the Canadian standard drainage test method, JIS is used except that 0.5 g of pulp is collected by absolute drying and the sieving board is made of 80 mesh plain woven bronze wire. The measurement was carried out by a method (modified drainage method) conforming to the Canadian standard drainage test method of P8121-2: 2012. When measured by the modified drainage method, it was described as "(modified)".

(Examples 1 to 12, Comparative Examples 1 to 11)
After dissociating NBKP at a concentration of 3%, it was prepared using a double disc refiner and a deluxe finer to obtain natural pulp having each physical characteristic value shown in Table 1. Then, a base sheet I having a basis weight of 40 g / m ^{2 was produced by a long net paper machine.} This base material sheet I was coated with a 40% aqueous solution of a water-soluble polyol described later using a rod bar so as to have the content shown in Table 1 after drying, and dried at 120 ° C. for 3 minutes to obtain paper. .. In Comparative Examples 2, 4 and 6, a 20% ethyl acetate solution of a water-insoluble polyol was applied after drying so as to have the content shown in Table 1, and dried at 85 ° C. for 1 minute to prepare the paper. Obtained. Further, in Comparative Examples 1, 3 and 5, the water-soluble polyol was not applied.

A 35% calcium chloride solution (manufactured by Tokuyama Corporation) is applied to the paper using a rod bar so that the calcium chloride content is 5 g / m ² after drying, and the paper is dried at 120 ° C. for 3 minutes to reach total heat. Interchangeable element paper was obtained.

Product name: SC-800: Made by ADEKA Corporation (water-soluble, polyether polyol)
Product name: T-400: Made by ADEKA Corporation (water-soluble, polyether polyol)
Product name: BPX-33: Made by ADEKA Corporation (water-soluble, polyether polyol)
Product name: TLM: Made by Toyokuni Oil Co., Ltd. (water-insoluble, polyester polyol)

[Strength evaluation method for total heat exchange element paper]
For the evaluation of strength, after adjusting the humidity for 24 hours under the conditions of 23 ° C. and 50% relative humidity using total heat exchange element paper, the test width is 15 mm, the test length is 180 mm, and the extension speed is 20 mm / in the flow direction. The tensile strength was measured under the condition of min. The evaluation criteria are as follows.

⊚: The tensile strength is very strong at 2.0 kN / m or more, which is extremely good.
◯: The tensile strength is strong and good when it is 1.5 kN / m or more and less than 2.0 kN / m.
Δ: The tensile strength is 1.0 kN / m or more and less than 1.5 kN / m, which is within the permissible range.
X: The tensile strength is weak at less than 1.0 kN / m and cannot be used.

[Method of manufacturing total heat exchange element]
In order to evaluate the shielding property, a total heat exchange element having a length of 200 mm, a width of 200 mm, a height of 250 mm, and a step height of 4 mm was produced using total heat exchange element paper. ^{At this time, 70 g / m 2} of bleached kraft paper was used as the spacing plate (spacer) for the total heat exchange element, and an ethylene-vinyl acetate copolymer resin-based adhesive was used for bonding each member. A orthogonal flow type total heat exchange element having the shape shown in FIG. 1 was produced.

The total heat exchange element having the shape of FIG. 1 will be described in detail. In the total heat exchange element 1 for total heat exchange, the total heat exchange element partition plate 2 (partition material, liner) is laminated via the total heat exchange element spacing plate 3 (spacer) to allow outdoor air to flow indoors. The air supply path 4 to be introduced into the air supply path 4 and the exhaust path 5 for discharging the indoor air to the outside are configured, and the air supply path 4 and the exhaust path 5 are independent. Airflows 6 and 7 flow through the air supply path 4 and the exhaust path 5, and total heat exchange is performed between the partition plates 2 for the total heat exchange element. If the room is ventilated by a total heat exchanger provided with such a total heat exchange element 1, the cooling and heating efficiency can be greatly improved.

Further, the partition plate 2 for the total heat exchange element is placed between the upper and lower interval plates 3 for the total heat exchange element when laminating the interval plate 3 for the total heat exchange element, and is adhered by an adhesive. The heat exchange element 1 is manufactured.

[Evaluation method of shielding (carbon dioxide leakage)]
Synthetic air gas containing nitrogen: oxygen at 79:21 was ventilated from the air supply side of the produced total heat exchange element, and contaminated gas containing carbon dioxide was ventilated to the exhaust side at a constant concentration for ventilation. .. The carbon dioxide concentration was measured at the outlet on the air supply side, compared with the carbon dioxide concentration at the inlet on the exhaust side, and the amount of carbon dioxide leakage was calculated in "% display". The evaluation criteria are as follows.

⊚: The amount of carbon dioxide leaked is less than 0.1%, which is very small and extremely good.
◯: The amount of carbon dioxide leakage is 0.1% or more and less than 1%, which is good.
Δ: The amount of carbon dioxide leaked is 1% or more and less than 5%, which is within the permissible range.
×: The amount of carbon dioxide leaked is as large as 5% or more and cannot be used.

[Evaluation method of heat exchange performance]
The heat exchange performance of each total heat exchange element produced was evaluated according to JIS B8628: 2003. The heat exchange performance of the total heat exchange elements of Examples 1 to 12 and Comparative Examples 2 to 11 was evaluated according to the following evaluation criteria in comparison with the heat exchange performance of the total heat exchange elements of Comparative Example 1.

1: Bad 2: Somewhat bad 3: Equivalent 4: Somewhat good 5: Good

From the evaluation results in Table 1, it is composed of a base sheet containing natural pulp, and the base sheet contains natural pulp having a length-weighted average fiber length of 0.7 to 1.7 mm, and the natural pulp is a fiber. In the length histogram, the proportion of fibers having the maximum frequency peak between 0.5 and 1.5 mm and having a fiber length of 1.0 mm or more is 25.0% or more, and the base sheet is made of polyester. The total heat exchange element paper further containing a water-soluble polyol selected from the group of polyols, polyester polyols and polymer polyols and the total heat exchange element formed by using the total heat exchange element paper have strength and shielding property. And it can be seen that the heat exchange performance is excellent.

From Comparative Examples 3, 4, 7 and 8, it can be seen that when the proportion of fibers of 1.0 mm or more is less than 25.0%, the strength cannot be obtained. Further, from Comparative Examples 5, 6, 9 to 11, when the average fiber length is larger than 1.7 mm and / or when the fiber length of the maximum frequency peak is not in the range of 0.5 to 1.5 mm, the shielding property It turns out that is not obtained.

The total heat exchange element papers of Examples 7, 9 and 1 having a second peak in the range of 0.0 to 0.5 mm do not have a second peak in the range of 0.0 to 0.5 mm. It can be seen that the shielding property is further improved as compared with the total heat exchange element papers of Examples 8 and 10.

From the comparison between Examples 1 to 6 and 7 to 12 and Comparative Example 1, it can be seen that when the total heat exchange element paper contains a water-soluble polyol, the heat exchange performance as the total heat exchange element is improved. The total heat exchange elements of Examples 1 to 6 use total heat exchange element paper in which the content of the water-soluble polyol is changed, but the heat exchange performance of the total heat exchange element is improved according to the content. It has been improved and the heat exchange performance of the total heat exchange elements in Examples 3 and 4 has reached saturation. Examples 1-6, the content of the water-soluble polyols, preferably 0.3 to 10 / ^{m 2,} it is understood that more preferably 0.5 to 5 g / ^{m 2.}

Further, comparing Example 1 in which the total heat exchange element paper contains a water-soluble polyol and Comparative Example 2 in which the total heat exchange paper contains TML, which is a water-insoluble polyol, the total heat exchange element Although the strength, shielding property, and heat exchange performance were the same, Comparative Example 2 was not preferable because the coating process on the total heat exchange paper was complicated.

Similarly, when Comparative Example 1 and Comparative Example 2, Comparative Example 3 and Comparative Example 4, and Comparative Example 5 and Comparative Example 6 are also compared, the former of each set does not contain a polyol, and the latter is water-insoluble. However, the latter of each set was not preferable because the coating process on the total heat exchange paper was complicated and the strength and shielding property were also inferior.

The total heat exchange element paper and the total heat exchange element of the present invention supply fresh air and exchange humidity (latent heat) as well as temperature (sensible heat) when discharging dirty air in the room. Used for exchangers.

1 Total heat exchange element 2 Partition plate for total heat exchange element (partition material, liner)
3 Spacing plate (spacer) for total heat exchange element
4 Air supply path 5 Exhaust path 6, 7 Airflow

Claims (3)

A total heat exchange element paper composed of a base sheet containing natural pulp, wherein the base sheet contains natural pulp having a length-weighted average fiber length of 0.7 to 1.7 mm, and the natural pulp is In the fiber length histogram, the proportion of fibers having the maximum frequency peak between 0.5 and 1.5 mm and having a fiber length of 1.0 mm or more is 25.0% or more, and the base sheet is made of poly. A total heat exchange element paper further containing a water-soluble polyol selected from the group of ether polyols, polyester polyols and polymer polyols. The total heat exchange element paper according to claim 1, wherein the natural pulp has a peak between 0.0 and 0.5 mm in addition to the maximum frequency peak in the fiber length histogram. A total heat exchange element formed by using the total heat exchange element paper according to claim 1 or 2.

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