JP2022073486A - Heat insulating wall material for ventilation duct of building - Google Patents

Abstract

To provide a heat insulating wall material for a ventilation duct that is easy to mold in a desired wall shape, is self-supporting, can be reshaped, is light, and has a certain degree of dehydration.SOLUTION: A heat insulating wall material 2 comprises a heat insulating molded body 10 formed into a predetermined wall shape along a flow path of a ventilation duct 1 of a building. The heat insulating molded body 10 includes a laminated compression body 11 in which defibrated bodies 11a made of glass fiber are laminated and compressed, and an inorganic binder cured product 12 that is diffused in the laminated compression body 11 and connects the defibrated bodies 11a to each other. The density of the laminated compression bodies 11 in the heat insulating molded body 10 is 190 kg/m3 to 370 kg/m3.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat insulating wall material for a ventilation duct provided in a building.

In general, ventilation ducts such as kitchen exhaust ducts, air conditioning ducts, and chimneys of buildings are provided with heat insulating materials for heat resistance and heat retention. This type of ventilation duct insulation is composed of fiberglass felt and calcium silicate.

Japanese Unexamined Patent Publication No. 2018-11229 Japanese Unexamined Patent Publication No. 2020-003105

The heat insulating material for a ventilation duct made of glass fiber felt is difficult to form into a desired wall shape, and even if it is formed, it is difficult to stand on its own and maintain the wall shape.
Insulation for ventilation ducts made of calcium silicate is relatively dense and heavy. In addition, it is inferior in dehydration after absorbing water, and it takes time to dry.
In view of the above circumstances, it is an object of the present invention to provide a heat insulating wall material for a ventilation duct which is easy to form into a desired wall shape, can stand on its own and can retain its shape, is light, and can secure dehydration. do.

In order to solve the above problems, the present invention is a heat insulating wall material in a ventilation duct of a building.
The heat insulating molded body is provided with a heat insulating molded body formed into a predetermined wall shape along the flow path of the ventilation duct, and the heat insulating molded body includes a stacked compressed body in which glass fiber defibrated bodies are stacked and compressed, and the stacked body. It contains an inorganic binder cured product that is diffused into the compressed body and joins the defibrated bodies to each other.
The density of the stacked compressed body in the adiabatic molded body is about 190 kg / m ³ to 370 kg / m ³ .
As a result, it is possible to obtain a heat insulating wall material for a ventilation duct, which is easy to form into a desired wall shape, can stand on its own and can retain its shape, is lightweight, and can secure a certain degree of dehydration.

It is preferable that the thickness reduction degree is 60% or less when both sides of the heat insulating wall material for the ventilation duct are sandwiched between backing plates and a bolt is passed through to apply a tightening torque of 20 Nm. As a result, the tightening resistance of the heat insulating wall material and thus the self-supporting shape retention can be reliably ensured. From the viewpoint of ensuring the tightening resistance of the heat insulating wall material and thus the self-supporting shape retention, it is more preferable that the density is more than 250 kg / m ³ and about 370 kg / m ³ or less.
The weight loss ratio of the heat insulating wall material for ventilation ducts 25 hours after the start of dehydration after water absorption with respect to the weight at the time of substantially complete water absorption is at a temperature of 20 ° C to 30 ° C and a relative humidity of 60% RH to 80% RH. , 6% or more, more preferably 8% or more, and even more preferably 9% or more. This makes it possible to ensure the dehydration of the heat insulating wall material. From the viewpoint of reducing the weight of the heat insulating wall material or ensuring dehydration, it is more preferable that the density is about 190 kg / m ³ or more and less than 200 kg / m ³ .
Since it is the time of substantially complete water absorption, it is not limited to the stage where the heat insulating wall material completely absorbs water, but it may be the stage where water is almost completely absorbed. .. Normally, when the heat insulating wall material is immersed in water, it becomes almost completely absorbed in water, and even if water absorption is continued thereafter, the weight increase due to water absorption hardly occurs.

The density of the stacked bodies in which the defibrated bodies are stacked before compression is preferably about 100 kg / m ³ to 200 kg / m ³ .
In the stacked compressed body, a large number of streaky portions extending in the thickness direction are dispersed in the in-plane direction, and it is preferable that the defibrated bodies are entangled with each other in each streak portion.
The thickness direction refers to the direction connecting the inner side surface (the surface facing the flow path) and the outer surface of the heat insulating wall material. The in-plane direction refers to a direction along a surface orthogonal to the thickness direction, or a direction along the inner surface or the outer surface. Preferably, the stack is compressed in the thickness direction to become the stack compress.

It is preferable that the heat insulating wall material for a ventilation duct further includes a surface layer sheet covering the surface of the heat insulating molded body, and the surface layer sheet is directly adhered to the heat insulating molded body by an inorganic binder cured product on the surface. The surface may be the outer surface of the heat insulating molded product, the inner surface, or the flow path image plane.

According to the present invention, it is possible to obtain a heat insulating wall material for a ventilation duct which is easy to form into a desired wall shape, can be self-supporting and can retain its shape, is lightweight, and can secure a certain degree of dehydration.

FIG. 1 is a cross-sectional view of a ventilation duct for a building according to an embodiment of the present invention. FIG. 2 is a perspective view of the ventilation duct for a building. FIG. 3 is an exploded perspective view of the ventilation duct for a building. FIG. 4 is an explanatory view explanatoryly showing an enlarged cross-sectional structure of the heat insulating wall material of the ventilation duct for a building. 5 (a) to 5 (h) are explanatory views of the manufacturing process of the heat insulating wall material.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 and 2 show a ventilation duct 1 for a building. The building may be a house, an office building, or a factory. The ventilation duct 1 for a building may be a kitchen exhaust duct, an air conditioning duct, or a chimney (smoke exhaust duct).
The ventilation duct 1 for a building has, for example, a cylindrical shape.

As shown in FIGS. 1 and 3, the ventilation duct 1 for a building includes a heat insulating wall material 2 and an inner surface member 3. The heat insulating wall material 2 includes a pair of heat insulating molded bodies 10 and a surface layer sheet 4. The heat insulating molded body 10 is molded according to the wall shape of the ventilation duct 1 for a building. For example, each heat insulating molded body 10 has a half-divided cylindrical shape. The two heat insulating molded bodies 10 are combined to form a cylindrical heat insulating wall material 2.
Although not shown, an adhesive tape or an adhesive is used as a means for joining the heat insulating molded bodies 10.

As shown in FIG. 4, the adiabatic molded body 10 includes a stacking compressed body 11 and an inorganic binder cured product 12. The stacked compressed body 11 is obtained by compressing a large number of glass fiber defibrated bodies 11a and a stacked stacked body 11x.
The glass fiber contains SiO ₂ as a main component, and may also contain Al ₂ O ₃ , Fe ₂ O ₃ , TiO ₂ , CaO, Na ₂ O, and the like. The content of SiO ₂ in the glass fiber is preferably about 50 to 98 wt%, more preferably about 60 to 95 wt%, and even more preferably about 70 to 95 wt%.
The defibrated body 11a of the glass fiber is preferably a long fiber, and the average length thereof is usually 10 mm or more, preferably 20 mm or more, more preferably 30 mm or more, still more preferably 50 mm or more. The average diameter of the defibrated body 11a is usually about 2 to 30 μm, preferably about 5 to 30 μm, more preferably about 5 to 20 μm, and even more preferably about 5 to 15 μm.
The density of the stacked body 11x (FIG. 5 (d)) on which the defibrated bodies 11a are stacked before compression is preferably about 100 kg / m ³ to 200 kg / m ³ .
The density of the stacked compressed body 11 in the heat insulating molded body 10 is about 190 kg / m ³ to 370 kg / m ³ .

The cured inorganic binder 12 is a cured inorganic binder 12a (FIG. 5 (e)) coated and impregnated on the stack 11x. The defibrated bodies 11a are bonded to each other via the cured inorganic binder 12. The inorganic binder cured product 12 is substantially uniformly dispersed over the entire area of the heat insulating molded product 10.
Preferably, the inorganic binder 12a is a thermosetting inorganic binder that is a liquid material at the time of coating and impregnation and is irreversibly cured by heating.
Examples of the main component of the inorganic binder 12a include silica, aluminum silicate and other clay minerals. The weight mixing ratio of silica and aluminum silicate is, for example, silica: aluminum silicate = 50:50 to 10:90.
Further, the inorganic binder 12a before curing also contains water and other liquids. The viscosity of the inorganic binder 12a can be adjusted by adjusting the blending amount of a liquid such as water. The aluminum silicate may be hydrous aluminum silicate.

The ratio of the defibrated body 11a to the heat insulating molded body 10 is preferably about 80 wt% to 90 wt%.
The ratio of the cured inorganic binder 12 to the heat insulating molded product 10 is preferably 10 wt% to 20 wt%.
In the heat insulating molded body 10, the remainder excluding the defibrated body 11a and the cured inorganic binder 12 is mostly occupied by voids (void portions or air layers). The volume ratio of the void (void portion) in the heat insulating molded product 10 is preferably about 0.1 vol% to 10 vol%, and more preferably about 0.5 vol% to 5 vol%. The voids are dispersed almost uniformly inside the heat insulating molded body 10.

A large number of streaky portions 13 are formed in the stacked compressed body 11 and thus the heat insulating molded body 10. Each of these streaky portions 13 extends in the thickness direction (diametrical direction, vertical direction in FIG. 4) of the heat insulating molded body 10, and also extends in the in-plane direction (circumferential direction and axial length direction, left and right in FIG. 4) of the heat insulating molded body 10. And the method of orthogonal to the paper surface), they are distributed and preferably arranged at almost uniform intervals. In each streak portion 13, the defibrated bodies 11a are intertwined with each other. The arrangement interval d ₁₃ of the streaks 13 is preferably about d ₁₃ = 0.1 mm to 10 mm, and more preferably about d ₁₃ = 0.5 mm to 5 mm.

The outer peripheral surface (surface) of the heat insulating molded body 10 is covered with a surface layer sheet 4 such as an aluminum glass cloth. The surface layer sheet 4 is directly adhered to and integrated with the heat insulating molded body 10 by an inorganic binder appearing on the outer peripheral surface of the heat insulating molded body 10. Separately, no adhesive for joining the surface layer sheet 4 is used.
The degree of thickness reduction when both sides of the heat insulating wall material 2 are sandwiched between backing plates made of steel plates and a tightening torque of 20 Nm is applied by penetrating a bolt is preferably 60% or less.
The weight loss ratio of the heat insulating wall material 2 25 hours after the start of dehydration after water absorption with respect to the weight at the time of substantially complete water absorption is in an environment of a temperature of 20 ° C to 30 ° C and a relative humidity of 60% RH to 80% RH. It is preferably more than 6%, more preferably 8% or more, and even more preferably 9% or more.

An inner surface member 3 is provided on the inner peripheral surface of the heat insulating wall material 2. The inner surface member 3 is composed of, for example, a metal tube having a circular cross section. The internal space of the inner surface member 3 is a flow path for fluids to be distributed such as kitchen exhaust air, air conditioning air, and chimney exhaust gas.
The metal pipe may be a spiral pipe made of galvanized steel plate or a stainless steel pipe. The material of the inner surface member 3 is not limited to metal, but may be resin, ceramics, paper, wood, or the like. The inner surface member 3 may be formed of a sheet similar to the surface layer sheet 4, and may be directly adhered to and integrated with the heat insulating molded body 10 by an inorganic binder appearing on the inner peripheral surface (surface) of the heat insulating molded body 10.

The building ventilation duct 1 is manufactured as follows.
As shown in FIG. 5A, glass fiber 2a as a material is prepared.
As shown in FIG. 5B, the glass fiber 2a is defibrated to obtain a defibrated body 11a. By depositing the defibrated body 11a, a stacked body 11x is formed.
As shown in FIG. 5 (c), a needle punching device 5 having a large number of needles 5a is used to perform needle punching (needle punching) on the stacked body 11x. A protruding barb 5c is formed on the needle 5a. Due to the high-speed reciprocating movement of the needle 5a, the defibrated bodies 11a are entangled with each other. As a result, as shown in FIG. 5D, the stacking body 11x becomes mat-shaped, and a large number of streaky portions 13 extending in the thickness direction of the stacking body 11x are formed.
The stack 11x at this stage is not shape-retaining and can be easily deformed by gravity or other external force.

Subsequently, as shown in FIG. 5 (e), the inorganic binder 12a is applied to both surfaces (upper surface and lower surface in the same figure) of the stack 11x. The coating is preferably carried out with a roller. It may be applied by spraying.
Instead of coating, the stack 11x may be impregnated with the inorganic binder 12a by immersing the stack 11x in an inorganic binder tank. In this case, it is preferable to immerse the upper surface side portion and the lower surface side portion of the stacking body 11x in the inorganic binder tank by half or less of the thickness of the stacking body 11x, respectively. It is preferable that a non-impregnated layer of the inorganic binder 12a is formed in the central portion of the stack 11x in the thickness direction. As a result, a void (air layer) can be secured in the stack 11x. Therefore, in the stage from coating or impregnation to compression molding described later, the content of the inorganic binder 12a in the stacking body 11x is high in the double-sided side portions (upper surface side portion and lower surface side portion) of the stacking body 11x, and the stacking body It is low in the central part in the thickness direction of 11x. Further, the abundance rate of voids (void portions) in the stack 11x is low in the double-sided portions of the stack 11x and high in the central portion of the stack 11x in the thickness direction.

As shown in FIG. 5 (f), the surface layer sheet 4 is attached to the upper surface of the stacked body 11x after coating or impregnation (the surface facing the outer peripheral side of the ventilation duct 1). The surface sheet 4 is directly adhered to the stack 11x by the inorganic binder 12a appearing on the upper surface of the stack 11x.

As shown in FIG. 5 (f), separately, dies 6 and 7 having mold surfaces 6a and 7a corresponding to the finished shape (half-split cylinder shape) of the heat insulating molded body 10 are prepared. A heater 8 is incorporated in at least one of the molds 6 and 7. In the figure, the heater 8 is composed of a plurality of rod-shaped heaters, but the heater 8 is not limited to this, and may be a plate heater or the like.

The stack 11x is set between the molds 6 and 7.
Subsequently, as shown in FIG. 5 (g), the molds 6 and 7 are closed, and the stack 11x is pressurized while being heated by the heater 8 to be compression-molded. It is preferable to use an air cylinder for pressurization.
The pressing force in the heating and compression molding steps is preferably about 0.1 MPa to 0.7 MPa. The heating temperature is preferably about 100 ° C to 400 ° C. The molding time (the duration of application of the pressing force and heating) is preferably about 3 to 30 minutes.
As a result, the stack 11x is compressed in the thickness direction to become the stack compress 11. Preferably, the thickness of the stacked compressed body 11 is compression-molded so as to be about half to four-fifths of the thickness of the stacked body 11x before compression.
Further, the heating increases the fluidity of the inorganic binder 12a, and further causes boiling, vaporization, and dissipation of the liquid component of the inorganic binder 12a. In this process, the solid component of the inorganic binder 12a is diffused over the entire area of the stack 11x to form the cured inorganic binder 12.
Further, the voids (void portions or air layers) in the stack 11x are reduced in volume by the compression of the stack 11x, and the inside of the stack compressor 11 is caused by the diffusion of the inorganic binder 12a and the vaporization / dissipation of the liquid component. Voids are diffused over the entire area of.
Then, as shown in FIG. 5 (h), the mold is removed.

As a result, the heat insulating molded body 10 having at least a part of the wall shape (half-split cylinder shape) of the duct 1 is formed. The self-supporting shape-retaining property of the heat-insulating molded body 10 is ensured by evenly joining the defibrated bodies 11a over the entire area of the heat-insulating molded body 10 via the inorganic binder cured product 12. Further, since the defibrated bodies 11a are entangled with each other in the streaky portion 13, it is possible to more reliably prevent the stacked compressed body 11 from being disassembled, and it is possible to further enhance the self-sustaining shape retention of the heat insulating molded body 10. can.
By using glass fiber as the main material of the heat insulating molded body 10, the heat insulating property and heat resistance of the heat insulating molded body 10 can be ensured.
Further, by using an inorganic binder instead of an organic binder as the binder, the heat resistance, fire resistance, and heat insulating property of the heat insulating molded product 10 can be ensured. In addition, the voids are uniformly dispersed over the entire area of the heat insulating molded body 10, so that the heat insulating property is further enhanced.
The surface layer sheet 4 is integrally laminated on the outer peripheral surface (surface) of the heat insulating molded body 10. The surface layer sheet 4 is directly bonded to the heat insulating molded body 10 by the inorganic binder cured product 12 on the outer peripheral surface (surface) of the heat insulating molded body 10. Since the inorganic binder cured product 12 serves as a joining means for the surface layer sheet 4, a separate joining means such as an adhesive is not required.

A pair of the heat insulating molded bodies 10 having a half-split cylinder shape are manufactured.
The pair of heat insulating molded bodies 10 are placed on both sides of a separately prepared inner surface member 3.
Further, the pair of heat insulating molded bodies 10 are joined by a joining means such as an adhesive tape or an adhesive. As a result, the cylindrical heat insulating wall material 2 is obtained.
In this way, the ventilation duct 1 for a building is obtained. The inner surface member 3 functions to prevent the defibrated body 11a from scattering from the inner peripheral surface of the heat insulating wall material 2. The surface layer sheet 4 functions to prevent the defibrated body 11a from scattering from the outer peripheral surface of the heat insulating wall material 2.
According to the embodiment of the present invention, the shape of the heat insulating molded body 10 and the shape of the heat insulating wall material 2 can be arbitrarily set by preparing molds corresponding to the wall shapes of various ventilation ducts for buildings.
By setting the density of the stacked compressed body 11 in the heat insulating molded body 10 to about 190 kg / m ³ to 370 kg / m ³ , a ventilation duct that can be self-supporting and can be kept in shape, is lightweight, and has a certain degree of dehydration. Insulated wall material can be obtained.
By setting the density to 190 kg / m ³ or more, preferably 250 kg / m ³ or more, and the thickness reduction degree to 60% or less, the tightening resistance of the heat insulating wall material 2 for ventilation ducts and the self-supporting shape retention are sufficient. Can be secured.
By setting the density to 370 kg / m ³ or less, preferably less than 200 kg / m ³ , and the weight reduction rate to preferably more than 6%, more preferably 8% or more, still more preferably 9% or more, the heat insulating wall material. 2 can be made lightweight, and dehydration as a heat insulating wall material 2 for a ventilation duct can be ensured.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the ventilation duct for a building is not limited to a kitchen exhaust hood, an air conditioning duct, and a chimney, and may be a ventilation duct or the like.
The shape of the ventilation duct is not limited to a cylindrical shape, but may be a square cylinder or a polygonal cylinder, or various other shapes. The heat insulating wall material may have a flat plate shape, a curved plate shape, or various other shapes.
The defibrated body 11a is not limited to long fibers, but may be short fibers.
The inorganic binder 12a is not limited to a thermosetting binder, and may be, for example, a water-curable binder that is cured by a hydration reaction or the like. The inorganic binder 12a may be one that is melted by heating to bond the defibrated bodies 11a to each other and then cured by cooling. The inorganic binder 12a may contain a dispersion medium or a solvent. The dispersion medium or solvent may be vaporized during heating. The dispersion medium or solvent may be water.
The surface layer sheet 4 may be provided on the inner surface (duct flow path image surface) of the wall-shaped heat insulating molded body. The surface layer sheet 4 may be directly adhered to the heat insulating molded body by an inorganic binder on the inner surface of the heat insulating molded body. The surface sheet may be omitted.

Examples will be described. The present invention is not limited to the following examples.
In Example 1, the tightening resistance according to the density of the heat insulating wall material was verified.
Samples 1 to 4 of a heat insulating wall material made of a heat insulating molded body containing a stacked compressed body and an inorganic binder cured product were prepared.
The vertical and horizontal sizes of the heat insulating wall material samples 1 to 4 were about 100 mm × about 100 mm, and the initial thickness (before tightening) was 19.7 mm to 20.7 mm. The thickness was measured at four points of each heat insulating wall material sample 1 to 4, and the average value thereof was adopted (the same applies to Example 2).
The initial density (before tightening) of the heat insulating wall material sample was 198 kg / m ³ to 367 kg / m ³ .
Both sides of each heat insulating wall material sample 1 to 4 are sandwiched between a pair of steel plate backing plates, a bolt is passed through one backing plate to the heat insulating wall material samples 1 to 4 and the other backing plate, and a nut is screwed in to 20 Nm. The degree of thickness reduction (thickness at the time of tightening / initial thickness) when the tightening torque was applied was measured.
As shown in Table 1, the measurement results were 59%, 50%, 42%, and 30%, respectively, and it was confirmed that sufficient self-sustaining shape retention as a heat insulating wall material for ventilation ducts was ensured.

In Example 2, the dehydration property after water absorption was verified according to the density of the heat insulating wall material.
Insulation wall material samples 5 to 8 composed of a heat insulating molded body containing a stacked compressed body and an inorganic binder cured product were prepared.
The vertical and horizontal sizes of the heat insulating wall material samples 5 to 8 were about 100 mm × about 100 mm, and the thickness was 20 mm to 20.8 mm.
The initial weight (before water absorption) of the heat insulating wall material sample was 0.041 kg to 0.073 kg.
The density of the heat insulating wall material sample was 205 kg / m ³ to 347 kg / m ³ .
These heat insulating wall material samples were immersed in water in a bucket to absorb water (water absorption step). After the heat insulating wall material sample was substantially completely absorbed by the water absorption step for 1 hour (60 minutes), it was taken out from the bucket and the weight immediately after was measured and found to be 0.220 kg to 0.244 kg.
The removed heat insulating wall material sample was allowed to stand in an environment having a temperature of 20 ° C. to 30 ° C. and a relative humidity of 60% RH to 80% RH to dehydrate it.
As shown in Table 2, the weight of the heat insulating wall material sample 25 hours after the removal (at the end of the water absorption process) is 0.197 kg to 0.221 kg, and the weight reduction rate is 9% to 10%. there were.

[Comparison example]
As a comparative example, a heat insulating wall material sample made of calcium silicate was prepared. The vertical and horizontal size of the heat insulating wall material sample made of calcium silicate was 99 mm × 99 mm, the thickness was 26.3 mm, and the density was 440 kg / m ³ . When the dehydration property of the heat insulating wall material sample made of calcium silicate was verified under the same conditions as in Example 2, the weight loss rate was 6%.
According to the heat insulating wall material according to the present invention, it was confirmed that the heat insulating wall material is lighter in weight and superior in dehydration property than the heat insulating wall material made of calcium silicate.

The present invention can be applied to, for example, ventilation ducts such as kitchen exhaust ducts, air conditioning ducts, and chimneys in buildings.

1 Ventilation duct for buildings 2 Insulation wall material 2a Glass fiber 4 Surface sheet 10 Insulation molded body 11 Stacked compressor 11a Defibering body 11 x Stacked body 12 Inorganic binder cured product 12a Inorganic binder 13 Streaks

Claims (3)

Insulated wall material in ventilation ducts of buildings
The heat insulating molded body is provided with a heat insulating molded body formed into a predetermined wall shape along the flow path of the ventilation duct, and the heat insulating molded body includes a stacked compressed body in which glass fiber defibrated bodies are stacked and compressed, and the stacked body. It contains an inorganic binder cured product that is diffused into the compressed body and joins the defibrated bodies to each other.
A heat insulating wall material for a ventilation duct, characterized in that the density of the stacked compressed body in the heat insulating molded body is 190 kg / m ³ to 370 kg / m ³ . 2. Insulated wall material for ventilation ducts. The weight reduction ratio of the heat insulating wall material for ventilation duct 25 hours after the start of dehydration after water absorption with respect to the weight at the time of substantially complete water absorption is at a temperature of 20 ° C to 30 ° C and a relative humidity of 60% RH to 80% RH. , The heat insulating wall material for a ventilation duct according to claim 1 or 2, wherein the temperature is more than 6%.

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