JP2001334510A - Woody fiber board and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a woody fiber board having an excellent heat insulating property. SOLUTION: A thermosetting resin is uniformely fused to a core part by hot air heating a mat M of a raw material mixture R containing a woody fiber and a thermoplastic resin, and the woody fiber is joined together to manufacture the woody fiber board of 0.03-0.08 g/cm2 in density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood fiberboard useful mainly as a heat insulating material for buildings and a method for producing the same.

[0002]

2. Description of the Related Art As a conventional heat insulating material, a sheet of inorganic fiber such as glass wool or rock wool, or a plate of synthetic resin foam such as polyurethane foam or polystyrene foam has been used.

[0003]

However, heat insulating materials made of these materials have no decay property, cannot be incinerated in the case of inorganic fiber sheets, and small pieces are scattered to contaminate the working environment. The body can be incinerated, but the polyurethane foam will emit toxic gases when incinerated, and the polystyrene foam will emit black smoke when incinerated, all of which cause significant air pollution. . Further, wood fiber boards in which wood fibers are bound by a thermoplastic resin have been conventionally provided, but such wood fiber boards are manufactured by heat compression molding or extrusion molding, and are not low-density, and are not heat-insulated. Not suitable as a material.

[0004]

According to the present invention, as a means for solving the above-mentioned conventional problems, a mat M of a raw material mixture R containing a wood fiber and a thermoplastic resin is heated with hot air to melt the thermoplastic resin. A wood fiber board to which the wood fibers are bound, the density of the wood fiber board being 0.03 to 0.08 g /
An object of the present invention is to provide a wood fiber board having a size of ³ cm ³ and a moisture-proof sheet attached to the front and / or back surface of the wood fiber board. The wood fibers have a diameter of 0.1-2.
It is preferably in the range of 0 mm and a length of 5 to 50 mm, with an average diameter of 0.5 mm and an average length of 30 mm.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below. [Wood fiber] The wood fiber of the present invention is produced by desiring a wood chip preferably by steaming and then defibrating by a defibrating machine. The scrap may be pulverized into chips, desirably steamed, and then defibrated by a defibrating machine. Desirable wood fibers have a diameter of 0.1 to 2.0 mm and a length of 5 to 50 mm, and have an average diameter of 0.5 mm and an average length of 30 mm.

[Thermoplastic resin] Examples of the thermoplastic resin used in the present invention include vinyl acetate resin, SBR, acrylic resin, styrene acrylic resin and the like. Desirable thermoplastic resins include polyolefins such as polyethylene and polypropylene. Since polyolefin is composed of only carbon and hydrogen, it is harmless to the human body,
No harmful gas is generated even by incineration. The thermoplastic resin is preferably in the form of powder, fibrous, or emulsion. When the thermoplastic resin is powder, regenerated powder obtained by crushing a molded article of synthetic resin or scrap of fiber is used. A product or a fibrous regenerated product obtained by melt-spinning the scrap can also be used.

[Raw material mixture] The wood fiber and the thermoplastic resin are usually mixed in a weight ratio of 8: 2 to 6: 4 as solids to solids. In addition to the above components, for example, a water repellent such as paraffin wax, polyethylene wax, silicone oil, or a flame retardant such as a phosphorus-nitrogen flame retardant or a boric acid flame retardant may be added.

[Production of Wood Fiber Board] FIG. 1 shows an example of an apparatus suitable for producing the wood fiber board of the present invention. In FIG. 1, (1) is a tank body, which is divided into an upper part (1A) and a lower part (1B).
(2) is stretched. The above net (2) is usually 40-6
A mesh of 0 mesh is used. A hot air blowing duct (3) is opened at the upper end of the upper part (1A) .The duct (3) has a hot air producing device (not shown) and a cold air supply duct (5) through a three-way valve (4) and a valve. The material supply hopper (6) is connected via (7). On the other hand, a valve is provided at the lower end of the lower portion (1B).
The suction path (8) marked (9) is connected.

[0009] In the above apparatus, the suction path in the tank body (1)
(8) Open the suction valve (7) using the hopper (6).
The raw material mixture R is sucked into the tank body (1) from the
Form a mat M on top. Then hopper (6)
The valve (7) is closed, and the hot air blowing duct (3) is opened by the three-way valve (4) to blow hot air into the tank body (1). The temperature of the hot air is set to be equal to or higher than the melting point of the thermoplastic resin contained in the raw material mixture R, and the thermoplastic resin is melted to bind the wood fibers. In this case, since the tank body (1) is sucked from the lower end by the suction path (8), the hot air is supplied to the mat M
The inside of the mat M can be smoothly melted, and the thermoplastic resin inside the mat M can be uniformly melted and uniformly bind the wood fibers.
Thereafter, a cool air supply duct (5) is connected to the hot air blow duct (3) by the three-way valve (4), and cool air is sucked into the tank body (1) to cool the mat M. The wood fiber board of the present invention is manufactured in this manner, and the wood fiber board is placed on the upper portion (1) of the tank body (1).
By separating A) and the lower part (1B), it is taken out from the tank body (1).

FIG. 2 shows an example of an apparatus used in the present invention.
Shown in In FIG. 2, reference numeral 11 denotes a tank body which is divided into an upper part (11A) and a lower part (11B), and a release-treated net (12) is stretched over the upper end of the lower part (11B). The upper part
At the upper end of (11A), a suction ventilation path (13) with a valve (14)
The raw material supply hopper (15) is connected to the suction / blast path (13) via a valve (16). The lower part (1
The lower end of 1B) is connected to a hot air blowing duct (17) with a valve, and the duct (17) is connected to a cold air supply duct (18) via a three-way valve (19).

In the above apparatus, the valve (14) and the valve (16) are opened, and the raw material mixture R is blown into the tank body (11) from the suction air passage (13) through the hopper (15). To form a mat M on the net (12). Next, after the release net (12A) is applied on the mat M, the inside of the tank body (11) is sucked by the suction air blowing path (13), and the tank body ( 11) blow hot air into
The hot air is passed through the mat M to melt the thermoplastic resin in the mat M and bind the wood fibers. In this case, the hot air passes through the inside of the mat M as in the previous example.
Although the thermoplastic resin in the inside is uniformly melted, there is an additional advantage that the raw material mixture in the mat M is evenly dispersed when the hot air passes through the inside of the mat M from below.

Next, a cold air supply duct (18) is connected to a hot air blow duct (17) by a three-way valve (19), and a suction air passage (1) is connected.
While the inside of the tank body (11) is sucked by 3), cool air is supplied into the tank body (11) to cool the mat M to produce a wood fiber board, and the wood fiber board is made of the tank body (11). It is removed by separating the upper part (11A) and the lower part (11B). As described above, since the forming of the mat M of the raw material mixture R is performed without pressing in the present invention, the density of the mat M can be reduced.

Although the above two devices are both batch type devices, the present invention also uses a continuous type device illustrated in FIG. This apparatus will be described below.
Is accumulated in a hopper (21), and is sprinkled on a forming net conveyor (24) from a supply roll (22) through a forming box (23) having a mesh stretched at the bottom, and the mat M is formed. The mat M is supplied from the forming net conveyor (24) to between the upper net conveyor (25) and the lower net conveyor (26), and is heated by a heating chamber (27) with hot air. The heating chamber (27)
The hot air blowout port (28) to which the hot air supply path (28) connects
A), a plurality of suction ports (29A) connected to the suction path (29) are arranged on the upper side, and the hot air blowing ports (2
The hot air blown from 8A) passes through the mat M, melts the thermoplastic resin in the mat M, and is sucked into the suction path (29) through the suction port (29A). Thus, the mat M
Is pressed by the upper and lower net conveyors (25, 26). It is sprayed and cooled, and becomes an original plate M ′ of a wood fiber board.

The original plate M 'is cut into a predetermined size by a cutter (32) to be a wood fiber board, and an adhesive A is spray-coated on a surface of the wood fiber board from a nozzle (33), and is then applied from a roll (34). The pulled out moisture-proof sheet (34A) is pressed from above by press rolls (35A, 35B), and the cutter (36)
Moisture-proof sheet (3
4A) is cut.

[Lamination of Sheets] As described above, a moisture-proof paper or a plastic sheet such as a polypropylene sheet, a polyethylene sheet or a polyester sheet may be adhered to one or both sides of the wood fiber board of the present invention as a moisture-proof sheet. The above-mentioned sheet is usually adhered to one or both sides of the wood fiberboard after the production by using an adhesive, or by heat fusion using high frequency, electromagnetic wave or the like. If the moisture-proof sheet is attached to the wood fiber board in advance, labor for attaching the moisture-proof sheet on site can be saved.

Example 1 A wood fiber board was manufactured using a raw material mixture having the composition shown in Table 1 by the apparatus shown in FIG. Hot air is blown from above and the hot air temperature is 150
° C and the blowing time were set to 10 minutes.

Example 2 A wood fiber board was manufactured using the raw material mixture shown in Table 1 by an apparatus shown in FIG. Hot air blowing was performed from below, the hot air temperature was set at 190 ° C., and the blowing time was set at 10 minutes. In this example, after manufacturing a wood fiber board, a vinyl acetate emulsion type adhesive (S-400, trade name, manufactured by Sumitomo Chemical Co., Ltd.) was sprayed on the surface, and moisture-proof paper was adhered.

Example 3 A wood fiber board was produced in the same manner as in Example 1 except that the raw material mixtures shown in Table 1 were used.

Example 4 A wood fiber board was produced in the same manner as in Example 1 except that the raw material mixtures shown in Table 1 were used.

[Comparative Example 1] The raw material mixture of Example 1 was sprayed on a template to form a mat.
Hot pressing was performed at a temperature of 0 ° C. and a pressure of 3 kg / cm ² for 5 minutes to produce a wood fiber board. Table 1 shows the measurement results of the physical properties of the respective wood fiberboard samples.

[0021]

[Table 1]

According to Table 1, the samples of Examples 1 to 4 uniformly melt the thermoplastic resin as hot air passes through the mat and bind the wood fibers. In addition, a low-density plate can be obtained without pressing. As a result, a plate having excellent heat insulating properties (low thermal conductivity) is obtained. On the other hand, in the wood fiber board of Comparative Example 1 by hot pressing, the thermoplastic resin in the core is difficult to melt, and a board having a low density is hardly obtained. The resulting wood fiber board has poor heat insulation.

[0023]

According to the present invention, a wood fiber board excellent in heat insulation and high in strength and suitable as a heat insulating material for buildings can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view of one embodiment of an apparatus used in the present invention.

FIG. 2 is an explanatory view of another embodiment of the device used in the present invention.

FIG. 3 is an explanatory view of still another embodiment of the device used in the present invention.

[Explanation of symbols]

 M Matt R Raw material mixture

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2B260 AA02 BA01 BA15 BA19 BA26 CB01 CD02 DA01 DA08 DA18 DD02 EA01 EB02 EB04 EB06 EB11 EB13 EB19 EB21 EB42 EC01 EC03 EC18 2E001 DD01 GA03 JC01 JC02 JC03 JD01 4F100A01A01A01 AP03A AR00B AR00C BA03 BA06 BA10B BA10C CB00 DG01A DG10 DH00A EC031 EJ421 GB07 JA13A JB16A JD04B JD04C JJ03 YY00A

Claims (5)

[Claims] 1. A wood fiber board bound with wood fibers by heating a mat of a raw material mixture containing wood fibers and a thermoplastic resin with hot air to melt the thermoplastic resin. Wood fiber board having a density of 0.03 to 0.08 g / cm ³ 2. The wood fiber has a diameter of 0.1 to 2.0 mm and a length of 5 mm.
The wood fiberboard according to claim 1, which has a mean diameter of 0.5 mm and an average length of 30 mm, which is in a range of from 50 to 50 mm. 3. The wood fiber board according to claim 1, wherein a moisture-proof sheet is attached to a front surface and / or a back surface of the wood fiber board. 4. A raw material mixture obtained by mixing a thermoplastic resin with wood fibers is supplied onto a net to form a plate-like mat, and then hot air is blown in from above or below and sucked from below or above to form the plate-like mat. 3. The method of claim 1, wherein the thermoplastic resin in the mat is melted to bind the wood fibers.
Method for producing wood fiberboard described in 5. The net is provided with a raw material and a hot air blowing port or a suction port on an upper side, and is stretched substantially horizontally in a tank provided with a suction port or a hot air blowing port on a lower side. 4. The method for producing a wood fiber board according to item 4.