JPH10225915A - Woody fiber board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a woody fiber board being a board having superior heat insulation and sound absorption capabilities. SOLUTION: Ester fibers are dry blended and heated as an adhesive in woody fiber opened physically, and a blended material obtained by melting the above- mentioned ester fiber is compression formed into a predetermined configuration so as to form a woody fiber board (numeral reference 1 in Fig.). The woody fiber board has an excellent sound absorption around the zone exceeding 500Hz, and has an extremely improved sound absorption around the zone exceeding 1000Hz.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood fiber board which is used for building materials, inner walls of tunnels, acoustic parts, etc. and exhibits high heat insulation performance and sound absorption performance.
The present invention relates to a wood fiber board that exhibits high sound absorption performance even in a high frequency range.

[0002]

2. Description of the Related Art Conventionally, as a sound absorbing material that reduces indoor noise, adjusts reverberation time in an indoor acoustic plan, and contributes to the phenomenon of echo, so-called particle board, glass wool ( Glass fibers) and fiber boards (also called "insulation boards") are known.

[0003]

However, these gypsum boards, rawan plywood, particle boards, glass wool (glass fiber), insulation boards, and the like are densely filled with materials due to their structures. ,
Insulation is poor, and among them, even if it is considered to be excellent (eg, glass wool), the thermal conductivity is at most about 0.03 kcal / m · h · ° C. The normal incidence sound absorption coefficient of gypsum board, Rawan plywood, and particle board is 0.1 or less at most, and the normal incidence sound absorption coefficient of glass wool is 0.8 to 0.9. Further, the insulation board is said to have a relatively good normal incidence sound absorption coefficient, but still has a normal incidence sound absorption coefficient of at most 0.1 to 0.2.

Therefore, the applicant of the present application has already proposed a "wood fiber flame-retardant heat insulating material" in which the heat insulating performance is enhanced by interposing it in a structure such as a partition wall or a door (Japanese Patent Application No. 8-108).
No. 161150), the present invention utilizes the wood fiber flame-retardant heat-insulating material and forms it into a board shape so that it can be used as a building material or a structural material, and has high heat-insulating performance. In addition, it is an object of the present invention to provide a wood fiber board which is excellent in silence performance due to an air layer inside thereof, has excellent fire resistance, high heat insulation performance and high sound absorption performance.

[0005]

Means for Solving the Problems In order to solve the above problems, the invention of a wood fiber board according to claim 1 of the present application is to mix ester fibers with physically defibrated wood fibers and to mix the mixture. The mixed raw material obtained by heating and heat welding is formed into a predetermined shape under pressure. Further, the invention of the wood fiber board according to claim 2 of the present application is to perform a flame retardant treatment on a physically defibrated wood fiber with a flame retardant, and mix the ester fiber with the flame retarded wood fiber, The mixed raw material obtained by heating and heat-welding the mixture is formed into a predetermined shape under pressure.

The wood fiber board according to claims 1 and 2 of the present application is an organic material, is very light, has excellent noise reduction performance, has excellent fire resistance, has high heat insulation performance and high sound absorption performance. In particular, the board's sound absorption performance at normal incidence becomes better than when it exceeds 500 Hz,
The sound absorbing performance is remarkably improved from around 000HZ.
The thermal conductivity of this wood fiber board is about 0.0
It shows a high value of 6 kcal / m · h · ° C.

[0007] The invention of a wood fiber board according to claim 3 of the present application is characterized in that at least the surface of the wood fiber board has been subjected to a flame retardant treatment with a flame retardant. As described above, the wood fiber board according to the third aspect of the present invention provides a wood fiber board having not only the sound absorbing performance but also a high heat insulating performance by applying a flame retardant treatment to the surface of the flame retardant. Can be.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Hereinafter, the test results will be described after having been divided into (1), a wood fiber manufacturing process, (2), a flame retarding treatment process, (2), a heat welding process with an ester fiber, and a pressurizing process. (〓, Manufacturing Process of Wood Fiber) First, wood fiber is wood that has been physically defibrated and formed into a fibrous form (hereinafter, referred to as “wood fiber”). The fiber is not a fibrillation (scientific fibrillation) using a predetermined chemical or the like, but a fibrillation method (physical fibrillation) in which wood is mechanically and physically ground to form a fiber.

In order to manufacture such a wood fiber, the present applicant has already proposed as Japanese Patent Application No. 8-161150, but as shown in FIG. The wood chips are cooked under high temperature and high pressure to soften the wood chips, which are further ground by a pressurized wood defibrating machine to form fibers. That is, while the wood chips 1 put into the surge pin (raw material hopper) 4 pass through the steamer 3 including the first screw feeder 5, the second screw feeder 6, the cross conveyor 8, and the steaming tube 7, the wood chips 1 are not shown. When steamed under pressure in a cross conveyor 8 into which high-temperature pressurized steam having a maximum steam pressure of 10 kg / cm ² is injected from a boiler or the like and discharged from the cross conveyor 8,
It becomes a soft and finer wood chip.

Next, the soft and finer wood chips are then guided to a pressurized wood defibrating machine 10. The pressurized wood defibrating machine 10 is driven by a motor (not shown) and includes two disks (not shown) arranged at a predetermined interval. In the present embodiment,
The interval between the two disks was set to 0.5 mm, and 10 kg / cm ² of pressurized steam was applied to the defibrator 10 from a pressurizing port (not shown) to form the soft and finer wood. The chips are further defibrated.

Here, the finely defibrated wood fiber may or may not be subjected to the flame retarding treatment in the following step. That is,
The steps of the flame retarding treatment are described below, but the wood fiber that has not been subjected to the flame retarding treatment is manufactured by shifting to a heat welding step with an ester fiber and a pressurizing step described later. Samples (8) and (9) described below are manufactured in this manner.

(〓, Flame-retardant treatment step) Next, the defibrated wood fiber is sent to the blow cyclone 11, where the cotton-like wood fiber has a moisture content of 25 by a predetermined blown air. %, And then sent to a unraveling machine / constant supply conveyor 12. The unraveling machine
In the fixed-quantity supply conveyor 12, the cotton-like wood fibers are unraveled to reduce the bulk density, and further, in the next chemical solution impregnation step, 60 to 80 g / m so as to be impregnated at a predetermined ratio.
The amount is determined to be a predetermined amount of wood fiber ( ³⁾ , and is sent to the chemical liquid impregnating device 14 in that state. The chemical liquid impregnating device 14 is charged with a chemical liquid tank 16 filled with a chemical liquid 15, an inverted convex mesh conveyor 17 arranged in the chemical liquid tank 16, and impregnated with the chemical liquid. It is configured so as to pass through the chemical solution with the wood fiber sandwiched therebetween.
Then, in the present embodiment, the wood fiber is introduced, and after the wood fiber is completely impregnated with the chemical solution, the first to the third to the third liquid placed in the chemical solution tank 16 after about 30 seconds to several minutes. The liquid is pulled up and drained by the liquid removing rollers 19, 20, and 21. At this time, the wood fiber pulled up is pulled up with a liquid content of about 65 to 70%,
It is sent to the next step.

The chemical liquid is a chemical liquid for performing a flame retardant treatment on the wood fiber. In the present embodiment, 25 to 280 g of ammonium sulfate and 100 to 100 g of ammonium monophosphate are added per 1 kg of the chemical liquid. 12
0 g, boric acid 30-50 g, solid content / dope total 350 g,
It comprises 550 to 750 g of water and 5000 ppm of alkyl ketene dimer and 10,000 ppm of polyethylene glycol as trace components. As this kind of medicine, for example, Matsushima Koyo Chemical Co., Ltd. product flame retardant (TS-1000) may be used.

(〓, Step of heat welding with ester fiber and pressurizing step) Next, the wood fiber subjected to the flame-retardant treatment or the wood fiber not subjected to the flame-retardant treatment is treated with an ester fiber (for example, Unitika) as an adhesive. After mixing the "core-sheath type ester" (trade name: 4080) manufactured by the company, heating and heat welding to produce a mixed raw material, and heating and press-molding the mixed raw material will be described with reference to a flowchart. 2 shows the flow chart: First, the ester fiber is mixed with the wood fiber which has been subjected to the flame retardant treatment or the wood fiber which has not been subjected to the flame retardant treatment (S).
1). In this embodiment, the mixing of the wood fiber and the ester fiber is performed by dry mixing in which the wood fiber and the ester fiber are mixed by a mixer, or the wood fiber and the ester fiber are once dispersed in water, and then mixed with the water in a dispersed state. This was performed by wet mixing. As for the mixing ratio, the wood fiber and the core-sheath type ester were mixed at a weight ratio of 70%
Mix at 25%.

Next, the mixed raw material was placed in a mold having a predetermined size and pressed into a board having a predetermined shape to form a wood fiber board. This will be described with reference to FIG.
The mixed material is placed in a mold having a predetermined size (S2), preheated (S3), heated (S4), and subjected to pressure molding (compression molding). First, when an ester (for example, a core-sheath type ester) is heated, in this embodiment, the temperature is about 180 ° C.
Was heated and melted. In addition, when using the wood fiber board of the present embodiment, depending on the place of use and the purpose of use, when it is desired to change the color of the surface of the board and use it thinly, in such a case, use a low temperature. Take some time. Then, after pressure molding as described above (S5),
When it is formed into a board (S6) and cut (S7), a wood fiber board having a predetermined shape is manufactured. As described above, the thickness is 8 mm, and the weight is 109 mm.
An example of a wood fiber board having a bulk density of 0.16 g / cm ³ in g was manufactured (indicated by a symbol in FIG. 5 and a symbol 〓 in FIG. 6). In addition, the wood fiber board manufactured as the above-mentioned example has been subjected to the above-mentioned flame-retardant treatment step.

{Test 1} (Comparison test with conventional sound-absorbing material) With respect to one embodiment of the wood fiber board obtained (flame-retardant), four conventional boards (plaster board, gypsum board, etc.) The normal incidence sound absorption coefficient was compared with that of Lauan plywood, particle board, glass wool, and insulation board.

This test was conducted in accordance with JIS A1405 (a method of measuring the normal incidence sound absorption coefficient of building materials by the in-pipe method). FIG. 3 shows a test method and a test apparatus. The normal incidence sound absorption coefficient α ₀ was obtained from the following equation using the standing wave ratio (see FIG. 4).

[0018]

(Equation 1)

For the measurement, a large diameter (99 m
m) and a small-diameter (33 mm) sound absorption measurement tube were used. The test piece was cut out in a circular shape so as to fit into each tube without any gap, and was set so that the surface of the board was a sound incident surface. Then, use a large-diameter (99 mm) sound absorption tube
The sound absorption coefficient was measured at intervals of 1/3 octave in the range of 800 to 5000 Hz using a sound absorption tube having a small diameter (33 mm) of 00 to 1600 Hz.

The wood fiber board has a thickness of 8 mm and a bulk density of 0.16 g / cm ³ . On the other hand, the insulation board has a thickness of 9
mm and the bulk density is 0.29. The gypsum board has a thickness of 9 mm. Rawan plywood has a thickness of 12
mm and the bulk density is 0.59. The particle board has a thickness of 15 mm and 6 mm and a bulk density of 0.63 (reference numeral in Table 1). Also, 100H
The normal incidence sound absorption coefficient between 5.0 kHz and 5.0 KHz was measured.

FIG. 5 and Table 1 show the results.

[Table 1] FIG. 5 is a graph of the results in Table 1. Also, in FIG. 5, the symbols 符号 indicate changes in the normal incidence sound absorption coefficient of the wood fiber board, and the insulation board, the plaster board, the lauan plywood,
Shows the change in the normal incidence sound absorption coefficient of the particle board. As is clear from FIG. 5 and Table 1, the woody fiber board of one embodiment shows excellent normal incidence sound absorption performance, and particularly, the higher the frequency, the higher the normal incidence sound absorption coefficient. In other words, the sound absorbing performance is improved when the frequency exceeds 500 Hz, and the sound absorbing performance is significantly improved when the frequency exceeds 1000 Hz. This is in sharp contrast to the conventional one where the normal incidence sound absorption coefficient changes only slightly from the low frequency range to the high frequency range.

That is, the wood fiber board according to the present invention exhibits a sound absorbing performance of about 0.25 or more at 1 kHz, and has excellent performance as a silent board. Therefore, the present invention has an extremely excellent effect in removing noise in a medium-high frequency range that cannot be eliminated by a conventional board or the like. This is considered to be due to the influence of the thickness and the bulk density as described later. In this test, "normal incidence sound absorption coefficient" was examined.
ISA1409 (method of measuring reverberation chamber sound absorption coefficient) "is considered to have almost the same tendency.

{Test 2} (Heat Conduction Test) Next, a heat conduction test was performed. The thermal conductivity of the wood fiber board of one example was 0.06 kcal / m · h · ° C. The thermal conductivity of the wood fiber used as the raw material was 0.04 kcal / m · h · ° C. On the other hand, the thermal conductivity of glass wool is 0.03 kcal / m · h · ° C.,
Wood has a thermal conductivity of 0.15 to 0.3 kcal / mh
° C. In addition, the wood fiber shows such a value when the wood fiber is finely defibrated,
If the defibration state is poor and the lumps are small, the thermal conductivity will be worse.

From the test results of the normal incidence sound absorption coefficient and the thermal conductivity, it can be seen that the wood fiber board of one embodiment has high heat insulation performance and high sound absorption performance.

{Test 3} (Comparison test between flame-retarded and non-flame-retardant) Next, with regard to the above wood fiber board, the relationship between the flame-retarded and non-flame-retardant wood fiber boards was examined. Samples 1 to 10 were prepared.

Here, each of the sample pieces had an area of 60.8 cm ² . And a thickness of 2.
The normal incidence sound absorption coefficient between 250 Hz and 2000 Hz was measured for each of ten types of samples from 00 mm to 11.60 mm.

(Sample 1) A sample 1 having a thickness of 6.8 mm, a bulk density of 0.141 and a weight of 5.9 g was prepared. The wood fiber of Sample 1 was not subjected to a flame retardant treatment with a flame retardant.

(Sample 2) Sample 2 having a thickness of 6.96 mm, a bulk density of 0.159, and a weight of 6.8 g was prepared. Sample 2 was not flame-retarded with a flame retardant, like Sample 1. The change in the sound absorption coefficient of the sample 2 is shown as a symbol in FIG.

(Sample 3) A sample 3 having a thickness of 6.90 mm, a bulk density of 0.144 and a weight of 6.1 g was prepared. The wood fiber of sample 3 is sample 1
As in the above, it has not been flame-retarded by a flame retardant.

(Sample 4) A sample 4 having a thickness of 6.41 mm, a bulk density of 0.161 and a weight of 6.3 g was prepared. The wood fiber of sample 4 is sample 1
As in the above, it has not been flame-retarded by a flame retardant.

(Sample 5) Sample 5 having a thickness of 6.91 mm, a bulk density of 0.145 and a weight of 6.1 g was prepared. The wood fiber of sample 5 is sample 1
As in the above, it has not been flame-retarded by a flame retardant.

(Sample 6) Sample 6 having a thickness of 2.00 mm, a bulk density of 0.361, and a weight of 4.4 g was prepared. The wood fiber of sample 6 is sample 1
As in the above, it has not been flame-retarded by a flame retardant. The change in the sound absorption coefficient of the sample 6 is shown as a symbol in FIG.

(Sample 7) Sample 7 having a thickness of 2.27 mm, a bulk density of 0.316 and a weight of 4.4 g was prepared. The wood fiber of sample 7 is sample 1
As in the above, it has not been flame-retarded by a flame retardant.

(Sample 8) The thickness is 5.70 mm, the bulk density is 0.214, and the weight is 7.4 g. The wood fiber of this sample 8 was subjected to a flame retardant treatment with a flame retardant. The change in the sound absorption coefficient of the sample 8 is indicated by the symbol 〓 in FIG.

(Sample 9) The thickness is 11.60 mm, the bulk density is 0.190, and the weight is 13.4 g. The wood fiber of this sample 8 was subjected to a flame retardant treatment with a flame retardant. The change in the sound absorption coefficient of the sample 9 is shown as a symbol in FIG.

(Sample 10) The thickness is 8.39 mm, the bulk density is 0.138, and the weight is 7.0 g. The wood fiber of this sample 10 was not subjected to a flame retardant treatment with a flame retardant.

In Table 3, for ease of comparison, the thickness was 9.00 mm and the bulk density was 0.296.
The insulation board is also shown. This is shown in FIG.
Shown as center. Further, the above-mentioned sample is shown by a thick line. This is indicated by the symbol 〓 in FIG.

The results are shown in FIG.

[Table 2] FIG. 6 is a graph of the results in Table 2. As apparent from FIG. 6 and Table 2, in particular, Sample 8 (FIG.
The middle code) and sample 10 (symbol 〓 in FIG. 6)
The value was higher than that of one example. From this result, it is understood that high sound absorbing performance can be obtained without performing flame retardant treatment with a flame retardant. In addition, Sample 8 and Sample 10
Has a relatively large thickness, it can be seen that it is preferable to increase the thickness to a certain extent in order to exhibit higher sound absorbing performance. In this test, 25
Although the test was performed in a relatively narrow frequency band between 0 Hz and 2000 Hz, it is considered that the same sound absorbing performance is exhibited in other frequency bands. That is, according to the wood fiber board according to the present embodiment, the sound absorbing performance is particularly improved in the region of 500 Hz or more as the sound absorbing effect, and the sound absorbing performance is remarkably improved from around 1000 Hz. The thermal conductivity of this wood fiber board shows a high value of about 0.06 kcal / m · h · ° C. It is an organic material and very light.

Next, several application examples of the wood fiber board according to the present invention will be described. When the wood fiber board according to the present invention is used by enclosing it in a door or a wall, one surface of the wood fiber board is further subjected to a flameproof treatment. Here, at least one surface of the building material or the like needs to be subjected to a flame-proof treatment, but it goes without saying that the whole may be subjected to a flame-proof treatment. By performing the flame retardant treatment in this way, it is possible to provide a wood fiber board having both the sound absorbing performance and the heat insulating performance.
Further, it can be used such that this surface appears on the inner wall surface such as a wall structure.

The wood fiber mat is preferably made so that wood fibers on one surface are raised (fluffed). Such fluffing further enhances the sound absorbing performance.

The wood fiber mat of each of the above embodiments can be used in combination with a board or mat having high sound absorbing performance in a low frequency range. When used in combination with such a board or mat having high sound absorbing performance in the low frequency range, sound absorbing performance in a wide range from the low frequency range to the high frequency range is exhibited. Further, the wood fiber mat of one embodiment has a very light specific gravity and is soft because of the use of wood fiber. Therefore, it is also excellent in punching, transporting, and the like.

[0042]

The wood fiber board of the present invention is obtained by subjecting a physically defibrated wood fiber to a flame retarding treatment with a flame retardant, and dry-mixing the flame retarded wood fiber with an ester fiber as an adhesive. Due to the heat welding, excellent fire resistance, high heat insulation performance and high sound absorption performance are exhibited, and it is suitable for building materials and inner walls of tunnels.

[Brief description of the drawings]

FIG. 1 is a view showing a manufacturing process of the above-described embodiment, in which a wood chip is physically defibrated, and the defibrated wood fiber is impregnated with a flame retardant; FIG.

FIG. 2 is a flowchart showing a manufacturing process for press-molding a wood fiber board according to the present invention.

FIG. 3 is a conceptual diagram showing a normal incidence sound absorption coefficient measuring method and its apparatus.

FIG. 4 is a diagram showing a standing wave pattern at a normal incidence sound absorption coefficient.

FIG. 5 is a view showing the normal incidence sound absorption coefficient of the wood fiber board of the present invention in comparison with that of a conventional sound absorbing material.

FIG. 6 is a sample 1 of a wood fiber board of the present invention.
It is a figure which shows the normal incidence sound absorption coefficient of No. 10.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Wood chip, 10 ... Pressurized wood defibration machine, 14 ... Chemical liquid impregnation apparatus, 15 ... Chemical liquid 16 ... Chemical liquid tank

Claims (3)

[Claims] 1. A mixed raw material obtained by mixing an ester fiber with a physically defibrated wood fiber and heating and heat-welding the mixture to form a predetermined shape under pressure. Wood fiber board. 2. A physically fibrillated wood fiber is subjected to a flame retardant treatment with a flame retardant, an ester fiber is mixed with the flame retarded wood fiber, and the mixture is heated,
A wood fiber board obtained by press-forming a mixed raw material obtained by heat welding into a predetermined shape. 3. The wood fiber board according to claim 1, wherein at least the surface of the wood fiber board is subjected to a flame retardant treatment with a flame retardant.