JPS627503A - Heat insulating material and manufacture thereof - Google Patents

Abstract

PURPOSE:To enable to easily execute heat insulating work by a method wherein aggregate of cellulose fibers bonded by bonding agent is formed into a sheet. CONSTITUTION:Cellulose fibers obtained from old newspapers are bound by bonding agent as binder so as to form sheet-shaped cellulose aggregate. The resultant aggregate has undoubtedly various performances such as excellent heat resistance, sound absorbing property and the like, all of which are originally the performances of cellulose fiber. Further, in executing heat insulating work, the work can be completed only by laying the sheet-shaped cellulose aggregate or heat insulating material onto ceiling, floor and the like. Furthermore, the work can be finished in a short period of time, because no drying time of bonding agent, which is sprayed together with cellulose fibers in case of spraying method, is required.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a heat insulating material used to cover walls, ceilings, floors, etc. of buildings, and a method for manufacturing the same.

[Background Art J] Insulating materials are installed on the walls, ceilings, floors, etc. of buildings to block cold air in the winter and hot air in the summer. Conventionally, this heat insulating material is made of foamed polyurethane, glass fiber, or the like. However, foamed polyurethane has problems with fire protection due to its self-combustibility.
Furthermore, glass fibers have the problem that they act on human skin, causing discomfort and condensation, resulting in a reduction in insulation performance.

Therefore, in recent years, it has become popular to use cellulose fiber, a wood fiber, for insulation. Cellulose fiber itself contains air and has excellent heat insulation properties, as well as sound absorption properties.
Moreover, because it has a breathing effect that absorbs and releases moisture, there is no risk of moisture remaining, causing condensation, and reducing insulation properties.
It also has high flame retardant properties and does not have the same effect on the skin as glass fibers do, and these excellent features are why it is becoming popular. When performing insulation construction using such cellulose fibers, the construction is generally carried out using a spraying method. The spraying method uses cellulose fiber and # as a binder.
C and adhesive are ejected from a jetting device, mixed in the air, and in this state are sprayed onto a construction surface such as a wall, thereby forming a layer of cellulose:X fibers on the construction surface. be. However, when constructing a cellulose fiber insulation layer in this way, it is necessary to wait for the adhesive to dry after spraying, but the moisture inside the cellulose fiber layer Because the cellulose fibers and adhesives are trapped inside, it takes more than three days to dry, lengthening the construction period, and it is also necessary to bring a spraying device to the construction site to spray the cellulose fibers and adhesive. Therefore, there is a problem in that the construction for insulation becomes large-scale, and as a result, the construction cost for insulation construction becomes high.

[Object of the invention] The present invention has been made in view of the above points, and an object of the present invention is to provide a heat insulating material that can be easily installed by making use of the excellent properties of cellulose fiber.
A second object of the present invention is to provide a method for manufacturing a heat insulating material that can easily produce a heat insulating material that bends in a short period of time.

[Disclosure 1 of the Invention The heat insulating material according to the present invention is characterized in that cellulose 7:fibers are bonded using an adhesive as a binder, and the bonded aggregate of cellulose fibers is formed into a single plate, Furthermore, the method for manufacturing a heat insulating material according to the present invention is characterized by mixing cellulose fiber and an adhesive, placing the mixture in a mold, and drying the adhesive by subjecting it to heat wave dielectric heating. The present invention will be described in detail.

Cellulose fiber is a wood fiber, such as New W
Cellulose 7 Eyeper for I paper can be used.

Therefore, it is possible to use cellulose fibers recycled from old newspapers, and using old newspapers in this way is very advantageous in terms of recycling resources and low cost raw materials.

FIG. 1 shows an example of an apparatus for obtaining cellulose fibers from used newspaper. The used newspaper is fed from an input conveyor 3 to a pre-shredder 4, and is crushed within the pre-shredder 4. By pulverizing the waste newspapers in the pre-shredder 4 in this way, the cellulose fibers that make up the waste newspapers are shredded, and the cellulose fibers are fed into the surge bin 6 through the duct 5, and then opened by the notator 7. It is subjected to floating agitation action such as Next, the cellulose 7 eyelid in the surge bin 6 is sent to a duct 11 along with a discharge conveyor 8 formed by a screw conveyor provided at the bottom of the surge bin 6 and a discharge duct 10 equipped with a blower 9 installed at the top of the surge bin 6. This duct 11
The second is connected to chemical tanks 12 and 13, which are used to mix boric acid compounds, borax, etc. with the cellulose fibers.

Boric acid compounds have the effect of exterminating insects such as cockroaches, mites, and termites, expelling rats, and preventing mold. Furthermore, borax has a flame retardant effect, and although cellulose fibers have a flame retardant property, by adding borax in this way, the flame retardant property is improved, and when exposed to flame. This means that the fire can be prevented from spreading by simply scorching the area. For example, the boric acid compound is supplied from the first chemical tank 12 to the duct 11, and the boron f1N compound charged into the chemical preparation hopper 14 is transferred to the first The boric acid compound put into the chemical tank 12 and put into the first chemical tank 12 is taken out from the carry-out conveyor 17 and supplied into the duct 11 by the vibrating feeder 18.

Further, for example, borax is put into the second chemical tank 13, and the borax put into the chemical tank 13 of the IJS2 is carried out from the carry-out conveyor 19 and transferred to the vibrating feeder 18.
The liquid is supplied into the duct 11 through the duct 11.

In this way, the cellulose fibers mixed with chemicals such as boric acid compounds and borax in the duct 11 have metal objects removed when passing through the metal trap 20, and the cellulose fibers are further supplied to the finish mill 21. Then, it is subjected to a beating action in the finish mill 21. And cellulose fiber is Finish Mill 2
1 is sent into the tank 22, and the bubble tank 22
The agitator 23 in the tank gives a floating agitation effect to the cellulose fibers to lower the bulk density of the cellulose fibers, and the bag filter 24 in the upper part of the bunk 22 removes fine particles contained in the cellulose fibers as dust. Remove.

C) Cellulose 7 Ipar is discharged from the bubble tank 22 by a bubble tank discharge conveyor 25 formed by a slurry conveyor provided at the bottom of the bubble tank 22. At this time, a packaging bag 26 is placed over the outer surface of the tip of the casing of the bagger tank discharge conveyor 25, and in this state, cellulose 7 eyelids discharged from the bagger tank discharge conveyor 25 are packed in the packaging bag 26. Insert the packaging bag 26 filled with cellulose fiber into the packaging container 27 and press it with J428.The cellulose fibers in the packaging container 27 are pressed from above to a predetermined bulk density, and then the Cellulose 7 Eyeper is placed in the packaging bag 26. Encapsulate. At this time, the cellulose 7 eyelids leaking from the light bar tank discharge conveyor 25 are received by the tray 30 and returned to the duct 11.

The cellulose fibers sealed in the packaging bag 26 in this manner are stored and then sent to the next process. In the next process, the cellulose fibers taken out from the packaging bag 26 are mixed with an adhesive.

Any adhesive used for wood can be used without particular limitation, such as vinyl acetate-based, area-based, phenol-based adhesives, or mixtures or copolymer-based adhesives of these. Agents etc. can be used. When using these adhesives, in order to ensure uniform mixing with the cellulose fibers, the adhesive is diluted with water to lower the viscosity and increase in volume when mixed with the cellulose fibers. .

Usually, the adhesive is often diluted with water by about 5 times or more. The mixing ratio of cellulose fiber and adhesive is the adhesive! Although it varies depending on the type and the bulk density of the intended heat insulating material, it is generally preferable to use about 5 to 10 parts by weight in terms of dry weight of adhesive per 100 parts by weight of cellulose fiber.

If the amount of adhesive mixed is greater than this, the bonding of the cellulose fibers will be insufficient, and the strength of the resulting insulation material will tend to decrease.If the amount of adhesive mixed is less than this, the insulation will be reduced due to burning of the adhesive. The flame resistance of the material tends to decrease. The cellulose fibers and adhesive can be mixed using any commonly used mixing device such as a Henschel type mixer.

By putting the cellulose fibers mixed with the adhesive into a mold and drying the adhesive, the Cellulose 7 Eyeper is bonded using the adhesive as a binding agent, and the aggregate of the cellulose fibers is formed into a block shape. Although the heat insulating material according to the present invention is obtained, as mentioned above, the adhesive contains a large amount of water, and the water is released from the adhesive in the outer layer of the cellulose fiber aggregate for a short period of time. The adhesive evaporates and dries in a short time, but the adhesive in the inner layer loses moisture.
[It is difficult to remove and it takes time for this adhesive to dry. 1h+=″x, ￥f′:*laMta9*t
MrQ#1:2-2>,・″″c>s＊+
s:□ft 'l, 1: '> It: "r6&゛%
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Water evaporates rapidly from the adhesive
1 dries, and this dried adhesive traps moisture in the inner layer, and it takes a long time to completely dry the adhesive in the inner layer. This means that we have no choice but to manufacture materials.

If moisture is contained inside, the insulation performance of the insulation material will deteriorate.

Therefore, in the present invention, an aggregate of cellulose fibers is shaped by filling a mold with cellulose fibers mixed with an adhesive, and then introduced into a high-frequency electric heating device to dry the moisture by high-frequency dielectric heating. This is how it was done. When high frequency dielectric heating is performed,
The cellulose fiber aggregate is heated from the center due to the temperature increase due to the frictional heat of dipole molecular motion.
In particular, moisture generates a large amount of heat due to dielectric loss, and moisture evaporates from inside the cellulose fiber aggregate, and the adhesive dries from inside.The moisture then evaporates sequentially from the inner layer to the outer layer, causing the cellulose fibers to form. The adhesive is dried sequentially from the inner layer to the outer layer of the aggregate. Therefore, unlike when the adhesive in the outer layer of a cellulose fiber aggregate is dried first, moisture in the inner layer will not be trapped by the dried adhesive (this will speed up complete drying). During this high-frequency dielectric heating, it is preferable to blow air with a 77-degree fan to efficiently evaporate the water. You can select a frequency that is approved, for example, 13.56MH.
Although the heating time depends on the amount of cellulose fiber, it is usually about 15 to 20 minutes, and complete drying can be completed within this time.

By drying with high-frequency dielectric heating in this way, cellulose fibers are bonded using adhesive as a binding agent, and the bonded aggregate of cellulose fibers is formed into a block shape to obtain a block-shaped heat insulating material. It is. Normally, the insulation material is stored in the form of a block, and the block-shaped insulation material is sliced into a thickness that meets the needs of the construction site where the insulation material will be installed, finished as a plate-shaped insulation material, and then shipped. Construction is completed by arranging such plate-shaped insulation materials on walls, ceilings, floors, etc., and the spraying method described above involves spraying Cellulose 7 Fiber and adhesive as in the construction method. There is no need to wait for the adhesive to dry after installation, and there is no need to bring a spray device to the construction site to spray cellulose fiber and adhesive (as a result, insulation can be installed in a short time). There is no need to carry out construction using large-scale equipment.
Although it is easy to install and can be done at low cost, there is a risk that the insulation material made of cellulose fiber may chip at its edges due to impact during transportation. In such cases, non-combustible paper or flame-retardant paper may be pasted on one side of this plate-shaped heat insulating material for reinforcement.

Next, the present invention will be further explained using specific examples.

First, cellulose fibers were obtained from old newspaper using the apparatus shown in FIG. This cellulose fiber was used as a zero-order area vinyl instant adhesive (Instarpond R-10 manufactured by Shoei Chemical Co., Ltd.) with a bulk specific gravity of 0.04.
1) was diluted 5 times with water, 10 parts by weight (converted to the dry weight of the adhesive) was added to 100 parts by weight of cellulose fiber, and the adhesive was uniformly mixed in Cellulose 7 Eyeper. The moisture content of Cellulose 7 Eyeper mixed with this adhesive was 55%.

Then, the cellulose fiber mixed with adhesive is placed in a stainless steel formwork 29 shown in Fig. 2, and the dimensions are a=
1800+m, b=1000mm, c=500 wheels m),
The cellulose fibers are pressed in a mold 29 by a wooden lower plate 32 and an upper plate 33, and an aggregate of cellulose 7-ipers is formed in the mold 29.

Next, the upper plate 33 and the formwork 29 are removed from the shaped cellulose fiber aggregate, and the shaped cellulose fiber aggregate 34 is placed on the lower plate 32 and subjected to high-frequency dielectric heating as shown in FIG. Installed on W131 (manufactured by Fuji Denpa Kogyo Co., Ltd.) with an output of 30KW.

High frequency dielectric heating was performed for 15 minutes at an oscillation frequency of 13.56 MHz. By drying in this way using high-frequency dielectric heating, the temperature of 2°C. -E7,6
7, -95□□r1800meX '1000
Molded into a block shape with dimensions of mm x 5100O
, one piece of insulation was obtained. This insulation material contains water
The i ratio was 10%, and the bulk specific gravity was 0.15.

Then, this block-shaped insulation material A is cut into a thickness of 10a+m as shown in Fig. 4 using a horizontal cutting machine (manufactured by Sakura Kikai Kogyo Co., Ltd.).
The plate-shaped heat insulating material B was obtained by slicing it into pieces of 30m thick, 50mm thick, and 100m5 thick.

The thus obtained heat insulating material was tested for its heat insulating performance and soundproofing performance. Regarding thermal insulation performance, the thermal conductivity was measured based on JIS A 1412, and the thermal conductivity was 0.0345 Kcal/mh°C. By the way, glass wool has λ=0.044, and rock wool has λ.
= 0.04, confirming the excellent heat insulating properties of the Cellulose 7 Eyer heat insulating material of the present invention. Regarding the soundproofing performance, the sound absorption coefficient at a frequency of 500 Hz by the reverberation chamber method and the transmission loss at a frequency of <500 Hz were measured based on JIS A 1416. The reverberation room sound absorption coefficient is 0.98 with a thickness of 50 mm, and the transmission loss is 2.
A 5mm-thick one placed on a 51-thick slate plate had a power output of 20.9dB.

[Effects of the Invention] As described above, the heat insulating material according to the present invention has cellulose fibers bonded together using an adhesive as a binder, and this bonded aggregate of cellulose fibers is formed into a plate shape. Not only does it have excellent thermal insulation and sound absorption properties, but also this insulation material, which is formed into a plate shape during construction, completes the insulation work by simply lining it up on the walls, ceiling, floor, etc. of the building. can,
With spraying, there is no need to wait for the adhesive to be sprayed on the cellulose fibers and poles to dry, unlike when using the construction method, and the construction can be completed in a short time. There is no need to bring in a large-scale spraying device to spray fibers and adhesive, and construction can be easily performed. In addition, the method for manufacturing a heat insulating material according to the present invention involves mixing Cellulose 7 Eyeper and an adhesive, placing the mixture in a mold, and drying the adhesive by high-frequency dielectric heating. By heating, the cellulose fiber aggregate can be heated from the center, moisture can be evaporated from the inside of the cellulose fiber aggregate, and the adhesive can be dried from inside. Unlike when the adhesive on the outer layer of the body is dried first, this dried adhesive does not trap moisture in the inner layer, allowing complete drying to occur quickly. It is something.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an apparatus for producing cellulose fiber, Fig. 2 is a perspective view showing an example of a formwork used to produce the heat insulating material of the present invention, and Fig. 3 shows the state of high-frequency heating. The schematic diagram shown in FIG. 4 is a perspective view showing a slice of the insulation material. ASB stands for insulation material.

Claims (2)

[Claims] (1) A heat insulating material characterized in that cellulose fibers are bonded together using an adhesive as a binder, and the bonded aggregate of cellulose fibers is formed into a plate shape. (2) A method for producing a heat insulating material, which comprises mixing cellulose fibers and an adhesive, placing the mixture in a mold, and drying the adhesive by high-frequency dielectric heating.