Blown-in cellulose fiber insulation

Abstract

Recycled pulp materials are becoming depleted. Material recycling of disposable diapers is also being encouraged. Blown-in insulation using cellulose fiber is in demand. [Solution] This is a residential insulation material that uses cellulose fiber containing recycled pulp material such as recycled newspapers and waste paper, recycled cellulose fiber, boric acid, and borax. It consists of 50% by weight of recycled pulp material from waste paper, 30% by weight of cotton-like pulp material extracted from disposable diapers, and 20% by weight of boron-based compounds. Cellulose fiber insulation is a multi-functional, cotton-like natural wood fiber insulation material made from waste paper such as newspapers, with flame retardancy, water repellency, and mold resistance added through chemical treatment. The entanglement of natural wood fibers creates layers of air, and natural air pockets exist within each individual fiber, further reducing the transmission of heat and sound. Furthermore, the moisture absorption and release properties unique to wood fibers maintain appropriate humidity levels, providing a comfortable living environment.

Description

Technical Field

[0006]

[0001] This invention relates to a cellulose fiber insulation material for blowing, more specifically, a cellulose fiber insulation material for blowing that utilizes the recycling of paper diapers.

Background Art

[0002] In cold-region houses, insulation materials for houses are installed, for example, in the attic, ceiling, and inner surface of outer walls. For example, an insulation layer provided in the ceiling space of a house is formed by blowing a large number of small pieces of insulation material obtained by crushing an insulation material such as an inorganic fiber mat into the ceiling space by an air flow and depositing them to a certain thickness.

[0003] Conventionally, the insulation material for blowing is manufactured by crushing an inorganic fiber mat such as glass wool or rock wool into a large number of small pieces of cotton, and then it is compression-packed in a plastic bag or the like and supplied. This is described in Patent Document 1 shown below.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0005] However, the conventional insulation material for blowing has the problems that when it is blown into the ceiling space to form an insulation layer, there are many voids, the density is lower than that of the inorganic fiber mat before crushing, or the density variation is large. The thermal conductivity is proportional to the density. When the density is low, the thermal conductivity becomes large and the insulation performance deteriorates. Also, when the density unevenness is large, the variation in thermal conductivity also becomes large, and the low-density part becomes a thermal drawback.

[0006] Furthermore, the insulation material for blowing manufactured by the above method also had the following problems. In other words, the small lumps of cotton tend to tangle with each other, and these lumps can easily get caught on the ceiling or other surfaces. Furthermore, when crushed small lumps of cotton are compressed and packaged for supply, they often tangle together to form large clumps. Even when the blown-in insulation material is supplied to a hopper equipped with an agitator and separated into individual lumps before being sent to a hose for air transport, it is not possible to completely break it down into small lumps. Instead, it is sent into the transport hose in fairly large clumps, which can easily cause blockages.

[0007] On the other hand, the use of disposable diapers has increased in recent years due to the aging population and the rise in the number of people requiring care. Consequently, the burden on local governments related to the disposal of used disposable diapers has become a major social problem. Used disposable diapers account for more than 4% of total general waste, and this figure is expected to increase. This is because they contain a lot of moisture, and the amount of heat generated during incineration is only about one-third that of combustible waste, similar to food waste, making them difficult to incinerate. This increases incineration costs and CO2 emissions. Therefore, recycling of disposable diapers is desirable, but the mainstream method of recycling involves processing them into RPF (fuel), etc., and then thermal recycling. Consequently, material recycling of used disposable diapers is desperately needed. [Means for solving the problem]

[0008] The invention described in claim 1 is a blown-in cellulose fiber insulation material manufactured by mixing a first pulp material obtained by crushing waste paper and a second cotton-like pulp material extracted from disposable diapers, paper napkins, and urine incontinence absorbent pads in a predetermined ratio, primary crushing these materials, adding boric acid and borax and stirring, secondary crushing, and compression molding. For example, recycled pulp material made from recycled newspapers, cardboard, and waste paper, recycled cellulose fiber (recycled pulp material) made from used disposable diapers (including liquid absorbent materials such as paper napkins and incontinence pads), and blown-in cellulose fiber insulation material containing appropriate amounts of boric acid and borax in addition to these. Note that disposable diapers contain cotton-like pulp in addition to absorbent material (SAP), and this cotton-like pulp is used as recycled pulp material. Cellulose fiber is generally manufactured by loosening and defibrating pulp (wood fibers) in water. Its insulation performance is equivalent to that of residential glass wool (24k, 32k), and its thermal conductivity is around 0.038 W / mk.

[0009] In this case, blowing in cellulose fiber insulation involves mixing the insulation with adhesive and water, spraying it onto the structure and walls (gaps) using a spray gun, and allowing it to air dry. The application is quick, but drying time is required, and there are limits to the thickness that can be applied in one go. Excess material can be trimmed off and reused. No dust is generated. This is the so-called blown-in insulation method. In addition to this, there are other methods, such as blowing cellulose fiber insulation into the ceiling space using a blowing device, and a method where a special sheet is first laid to create a space for filling, and then the insulation is blown into this closed space. The advantage of the blown-in method is that cellulose fiber insulation can be thoroughly filled even in small gaps. The designed insulation performance can be achieved during on-site construction.

[0010] The characteristics of this cellulose fiber insulation are as follows: 1) Moisture absorption and release performance The greatest advantage of cellulose fiber is the moisture-absorbing and releasing properties of the wood fibers. It creates a comfortable indoor environment without relying on ventilation or air conditioning. Wood fibers constantly require a small amount of moisture. Even completely dry wood has a humidity-regulating function. Wood is ideal for regulating humidity in homes in Japan's unique hot and humid environment. 2) Condensation prevention performance If there are small gaps in the insulation, those areas will be cooled or heated differently. This temperature difference between the inside and outside is the cause of condensation. Cellulose fiber can be installed without gaps, and because cellulose is permeable and absorbs and releases moisture, it is an insulating material that is highly resistant to condensation. Because cellulose fiber can be filled without gaps, it exhibits high performance as an insulating material, and at the same time, it can be expected to effectively prevent condensation. Furthermore, because the installation method involves blowing and filling with fibrous cellulose, it can be applied without gaps even in small areas, making it an ideal insulation material for preventing moisture that causes condensation and mold. 3) Anti-mold and insect-repellent performance Cellulose fiber contains boric acid. Boric acid has low toxicity and virtually no accumulation or residue in the human body. Boric acid is an excellent wood preservative. Specifically, it has only a weak acute aging effect on mammals, is effective against lower animals and microorganisms, and is colorless and odorless. It can also treat difficult-to-impregnate wood to the core (by diffusing through wet wood) and does not corrode metals. 4) Sound absorption and sound insulation performance Cellulose fiber contains air within each individual fiber, and this thick layer of air absorbs sound and makes it difficult for sound to be transmitted. Furthermore, because it is installed in a dense, gap-free manner, the house becomes airtight, resulting in high sound absorption and sound insulation performance.

[0011] 5) Thermal insulation performance Cellulose fiber is a natural wood fiber. Wood fibers contain a lot of air. This air is what gives cellulose fiber its insulating properties. Insulation materials trap air and suppress heat transfer, resulting in building materials with a thermal conductivity of 0.06 W / (m·k) or less. By installing cellulose fiber without any gaps, it is possible to suppress the intrusion of solar heat in the summer and suppress the escape of heat that has been heated in the winter. 6) Fire resistance performance Cellulose fiber, whose main raw material is newspaper, has boric acid and borax added to prevent flames from spreading during a fire. Furthermore, because it is a natural material derived from wood (newspaper), it does not generate harmful gases during a fire, and the insulation material will not melt due to heat. 7) Energy saving and ecology Cellulose fiber, a "recycled paper insulation material," requires less energy to produce compared to mineral-based fibers such as glass wool and rock wool. It is an environmentally friendly and eco-conscious insulation material. Specifically, the pulp used to make newspaper is derived from wood. Wood is finely crushed, dissolved in water with chemicals, and cellulose and helicrose are extracted to produce pulp, the raw material for paper. Paper recycling begins in room temperature water, so it does not require much energy. In contrast, recycling metals and plastics requires heating above the melting point of the material, resulting in the input of enormous amounts of energy. 8) Workability Insulation materials should be installed without gaps to prevent heat loss. Cellulose fiber insulation can be blown in without gaps into the area covered by the breathable sheet on the interior wall using a dedicated blowing machine. Perfect insulation reduces running costs for utilities. Cellulose fiber insulation is blown in without the use of adhesives, allowing for high-density insulation even in small gaps.

[0012] This blown-in cellulose fiber insulation is flame-retardant (preventing ignition during the manufacturing process) due to the addition of boric acid. The boric acid also provides insect-repellent properties. Furthermore, the boric acid provides water repellency, suppressing excessive moisture absorption. Mold growth is prevented by the boric acid. Because it is permeable to water vapor, it does not cause condensation within walls. Cellulose fiber itself has moisture-regulating properties (hygroscopicity). Because it is installed at high density to achieve insulation performance, it is heavy (more than three times heavier than 16K glass wool), and as a secondary effect, it provides extremely high sound insulation. A wall constructed with two sheets of rigid gypsum board and 10cm thick cellulose fiber provides a sound insulation effect of -60dB. With wall insulation using blown-in insulation, it's possible to install it without gaps, even around electrical outlets and bracing. Even in ceilings with pipes, wiring, and downlights, high airtightness and soundproofing can be achieved by seamlessly filling the ceiling with cellulose fiber insulation. This reduces the amount of airtight tape and adhesive used. It's non-irritating to the skin, minimizing discomfort to the skin and mouth during installation. Since it doesn't condense, vapor barriers and vapor layers are unnecessary.

[0013] In the case of borax, which is an additive for heat insulation materials, its aqueous solution is weakly alkaline, has a cleaning and disinfection effect, and exhibits a preservative effect (mold prevention).

[0014] The invention according to claim 2 is the cellulose fiber heat insulation material for blowing according to claim 1, which contains 50% by weight of the first pulp material, 30% by weight of the second pulp material, and 20% by weight of the boric acid and borax. The first pulp material is recycled pulp from waste paper, and the cotton-like pulp recycled from paper diapers is used as the second pulp material. When the content ratio of the latter is increased (for example, both the first and second pulp materials are 40% by weight), it has been confirmed that the thermal conductivity tends to increase.

Effects of the Invention

[0015] According to the invention described in claim 1, construction can be carried out at an appropriate density as a heat insulation material for blowing. In addition, it can promote the material recycling of paper diapers. Of course, it can exhibit excellent heat insulation effects as a heat insulation material for houses. Furthermore, in the house after construction, its moisture-proof and moisture-absorbing functions can be enhanced. Therefore, condensation prevention, mold prevention, pest prevention, high sound insulation, and high waterproofness can be achieved.

[0016] According to the invention described in claim 2, in addition to the above effects, it can clear a predetermined thermal conductivity (λ = 0.035 - 0.040) that is suitable as a heat insulation material. Furthermore, by compressing and packing during the manufacturing process of the heat insulation material, handling such as carrying it to the site becomes easy.

Brief Description of the Drawings

[0017] [Figure 1] It is a perspective view showing a cellulose fiber heat insulation material for blowing (test piece) according to Example 1 of this invention in a photograph. [Figure 2] It is a cross-sectional view showing the internal structure of a cellulose fiber heat insulation material for blowing (test piece) according to Example 1 of this invention. [Figure 3]This is a schematic diagram showing the configuration of a device for measuring the thermal conductivity of a blown-in cellulose fiber insulation material (test specimen) according to Embodiment 1 of this invention. [Modes for carrying out the invention]

[0018] Hereinafter, embodiments of the blown-in cellulose fiber insulation material according to this invention will be specifically described with reference to the drawings. [Examples]

[0019] The blown-in cellulose fiber insulation material according to Embodiment 1 of this invention will be described below with reference to Figures 1 to 3. First, the blown-in celos fiber insulation material according to this embodiment is manufactured by the following process. Specifically, the process includes: step A, preparing a first pulp material (pulp recycled from waste paper); step B, preparing a second pulp material (cotton-like pulp derived from disposable diapers); step C, mixing the first and second pulp materials in a predetermined ratio; step D, primary grinding of the mixture; step E, adding boric acid and borax to the ground mixture; step F, stirring the mixture after the additions; step G, secondary grinding of the stirred mixture; step H, compressing the ground material; and step I, packaging the compressed ground material.

[0020] The first pulp material in Step A is mainly manufactured using recycled newspapers, cardboard, and other materials. The raw materials are not limited to recycled waste; surplus items that did not enter the market are also used. Step B involves, for example, agitating the collected used diapers with water and a decomposing agent (agitating the diapers in water to remove waste), breaking them down into the surface material, absorbent material (SAP), and other components that make up the diapers, extracting the wastewater containing the separated pulp, separating the wastewater into water and pulp using a rotary screen, and dewatering the pulp using a screw dewaterer to produce recycled pulp. Additionally, cotton pulp from paper napkins can be used as a substitute for or in place of disposable diapers. Furthermore, this insulation material is manufactured by cutting and stirring the mixed cellulose raw materials (a mixture of pulp materials), and then adding boric acid and ammonium sulfate as flame retardants. This prevents the generation of frictional heat during the crushing of the mixture. Furthermore, commercially available products will be used for these manufacturing devices, such as crushing equipment, agitators, compression presses, and balers. In addition, boric acid and borax will be commercially available products.

[0021] The blown-in cellulose fiber insulation material manufactured through the above process (50% by weight of recycled paper pulp as the first material, 30% by weight of recycled cotton pulp as the second material, and 20% by weight of boric acid and borax) was confirmed to meet the specified standard value for thermal conductivity in the tests shown below.

[0022] The test method was based on the tests conducted by the Japan Building Research Institute (JIS A9523:2023 "Blown-in fibrous insulation" 6.3 Thermal conductivity). The measurement method was based on JIS A 1412-2:1999 "Method for measuring thermal resistance and thermal conductivity of thermal insulating materials - Part 2: Thermal meter flow method (HFM method)". An overview of the test apparatus is shown in Figure 3. The test specimen is shown in Figure 1 (perspective view of the test specimen) and Figure 2 (cross-sectional view thereof). The thermal conductivity λ and thermal resistivity R of the test specimen in the apparatus shown in Figure 3 are calculated using the following formulas. λ = q × d / ΔT, R = ΔT / q λ: thermal conductivity, R: thermal resistance, q: heat flux density, d: thickness of the specimen, ΔT: temperature difference of the specimen (Θ1-Θ2), Θ1: surface temperature on the high-temperature side of the specimen, Θ2: surface temperature on the low-temperature side of the specimen. The apparatus type is: one test specimen, symmetrical configuration; the type of calibration standard plate is: extruded polystyrene foam; the test specimen orientation is horizontal; and the heat flow direction is upward.

[0023] The manufactured insulation material is installed at the site using either a blown-in or spray-on method. For example, the insulation material is unpacked, mixed with water, and then blown into the wall surface, for instance. As a result, the high insulation effect makes it possible to create a house that is cool in the summer and warm in the winter. Furthermore, this insulation material is an ecological resource that is kind to both the planet and people. In addition, the insulated walls, once installed, can absorb moisture, allowing them to maintain a comfortable indoor temperature. In addition, the construction can prevent condensation and mold. It increases the durability of houses and residences. It can suppress deterioration. It can prevent pests such as termites. It can create a quiet home with high sound insulation performance. It can also achieve high fire resistance, making the house more resistant to fire.

[0024] A key characteristic of cellulose fiber insulation is its thermal conductivity (around 0.038 W / mk), which is largely unaffected by blowing density. The main raw materials for cellulose fiber insulation are recycled paper such as newspapers and cotton-like pulp derived from disposable diapers. A suitable amount of boron-based compounds is added for flame retardancy. Cellulose fiber insulation has many air pockets within its fibers, and in addition, the fibers intertwine to maintain air layers, resulting in excellent sound absorption. It provides sound insulation for partition walls in apartment buildings and reduces noise from outside the house. Cellulose fiber insulation has the moisture absorption and release properties characteristic of wood fibers. By absorbing and releasing moisture in response to changes in temperature and humidity, cellulose fiber insulation suppresses condensation within the wall structure, improving the indoor temperature and humidity environment. Insulation materials that primarily use recycled materials consume very little energy during manufacturing. This "cellulose fiber insulation" brings tangible results to the realization of a low-carbon society, from manufacturing and installation to occupancy and demolition. By preventing insulation defects through proper installation, it can significantly contribute to reducing heating and cooling energy consumption during occupancy and extending the lifespan of buildings.

[0025] In particular, the following effects become noticeable when this blown-in cellulose fiber insulation is installed. (Moisture absorption and release performance) The greatest feature of cellulose fiber is its moisture-absorbing and releasing properties, which allow it to regulate humidity. (Condensation prevention performance) Cellulose fiber insulation is not only installed without gaps, but because cellulose has moisture permeability and moisture absorption / release properties, it is a highly condensation-resistant insulation material. Since cellulose fiber can be filled without gaps, you can expect both excellent insulation and a significant reduction in condensation. (Anti-mold and anti-insect properties) Cellulose fiber contains boric acid, which acts as an excellent wood preservative. (Sound absorption and sound insulation performance) Cellulose fiber contains air within each individual fiber, and this thick layer of air absorbs sound and makes it difficult for sound to be transmitted. Furthermore, when installed with a dense, gap-free filling, the house becomes airtight, resulting in high sound absorption and sound insulation performance. (Thermal insulation performance) Cellulose fiber is a natural wood fiber, and wood fibers contain a lot of air. Air is the best insulator, and that's what gives cellulose fiber its insulating properties. (Fire resistance) By adding boric acid and borax, the flame will not spread even if ignited. (Energy saving and ecology) Cellulose fiber, made from recycled paper, requires no energy for production. It is an environmentally friendly and eco-conscious insulation material. (Workability) Cellulose fiber can be blown into an area covered with a breathable sheet using specialized machinery, ensuring there are no gaps. [Industrial applicability]

[0026] This invention is extremely useful as a technology for blown-in cellulose fiber insulation used in houses and other buildings.

Claims

1. A blown-in cellulose fiber insulation material is manufactured by mixing a first pulp material obtained by crushing waste paper and a second cotton-like pulp material extracted from disposable diapers, paper napkins, and urine incontinence pads in a predetermined ratio, first grinding these materials, adding boric acid and borax and stirring the mixture, second grinding it, and then compression molding it.

2. The blown-in cellulose fiber insulation material according to claim 1, comprising 50% by weight of the first pulp material, 30% by weight of the second pulp material, and 20% by weight of the boric acid and borax.

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