JP6000875B2 - Method for producing fine fibers for wooden insulation - Google Patents

Description

  The present invention relates to a method for producing fine fibers for a wooden heat insulating material.

  Insulation and soundproofing materials used in Japanese detached houses and small apartments include plastics such as polystyrene foam, mineral fibers such as glass wool and rock wool, foamed minerals such as foam glass, cellulose fiber, and wool. Natural materials such as wood materials are distributed in the market.

  In terms of heat insulation, plastics are superior, and in terms of durability, mineral fibers and foamed minerals are superior, and natural thermal insulation is superior in moisture retention and moisture absorption / resorption properties for water vapor in the air (for example, non-patent literature) 1 and 2, 3). In the natural environment of high humidity in Japan, the decay of wooden buildings due to condensation has a major impact on the durability of residential facilities, and natural thermal insulation that can suppress this has attracted attention. Yes.

  In addition, natural heat insulating materials are excellent in terms of manufacturing energy in the production process (see, for example, Non-Patent Document 1), and materials using wood material fibers or materials obtained by compressing and gathering wood materials have been proposed. (For example, refer to Patent Documents 1 and 2).

JP 2009-90669 A Japanese Patent No. 3607254

Satomi Nishikata “How to make the best thermal insulation and eco-house” (published by Knowledge Inc.) Junzo Yamamoto “Living in an unheated / cooled house” (published by Sanichi Shobo Co., Ltd.) Takahiro Takenouchi "A comfortable house is built with newspaper" (published by Shobo)

However, in the manufacturing process in Patent Document 1, a heat source such as a boiler is required to heat and soften by steaming at the time of defibration, and the raw material exposed to a high temperature dissipates heat during the manufacturing process, Heat energy is wasted.
Moreover, the thing which compresses and collects the small piece of the wooden material in patent document 2 has a large heat insulating material mass, and is inferior to a mineral fiber type heat insulating material in terms of construction and handling.
In the present invention, there is provided a method for producing fine fibers for a light-weight wood heat insulating material that suppresses energy required for production, effectively utilizes the energy inherent to wood materials, and has excellent construction and handling properties.

The above-mentioned problem of the present invention is that, in the method for producing fine fibers of a heat insulating material using a wood material as a main raw material, the solid content has a concentration of 0.1 mass percent or more in advance so that the moisture content of the wood material is 50 mass percent or more. Production of fine fibers for wood insulation, which is impregnated with an aqueous solution of caustic soda and subjected to multi-stage defibration by pre-defibration with a wet pulverizer and main defibration with a dry pulverizer to obtain refined fibers Achieved by the method.
Here, the moisture content of the woody material is indicated by the mass-based moisture content, dried and mass-measured by a method in accordance with JIS-Z2101, and the mass difference before and after drying is calculated as a percentage of the mass before drying. It is defined as the moisture content of.

The manufacturing method according to the present invention is shown in FIG.
In the present invention, the wood material A is used as the raw material of the fine fiber, and the impregnation treatment is performed in the step 1 using the caustic soda aqueous solution B having a solid content of 0.1% by mass or more, so that the water content is 50% by mass or more. Pre-defibrated fibers and the aqueous caustic soda solution in step 3 by pre-defibration in step 2 using a wet beating machine together with the aqueous caustic soda solution used for impregnation treatment, and squeezing or centrifuging and washing with water. Is separated and washed, and finally defibrated in step 4 by a dry-type beater and dried in step 5 to obtain fine fibers C.

  The aqueous caustic soda solution used for the impregnation treatment (hereinafter simply referred to as the impregnating solution) and the impregnating solution D separated in step 3 are mixed with the black liquor in the pulp manufacturing chemical solution collecting step 6 and heat energy is recovered with a recovery boiler. Therefore, it becomes possible to use the energy of the organic component inherent in the wood material such as lignin.

According to the present invention, energy necessary for production can be suppressed, energy inherent to the wood material can be effectively used, and fine fibers for lightweight wood heat insulating material excellent in construction and handling can be produced.
In addition, suppression of energy required for manufacture in the present invention means that heat energy that is wasted due to heat dissipation such as heating by steam is not required during the manufacturing process. Effective use of the energy inherent in the wood material means that the organic energy inherent in the wood material such as lignin is recovered and utilized in the pulp manufacturing chemical process. Being excellent in construction and handling properties means that it is lightweight and generates less dust when formed into a heat insulating material, and is evaluated by the bulk density of the sample and the amount of fine fibers that fall off when dropped.

It is a process flow of the present invention. It is a schematic diagram of the wet defibrating machine used for prior defibration. It is a schematic diagram of the dry type defibrator used for this defibration. It is a schematic diagram of the apparatus which draws and collects an evaluation sample.

  Hereinafter, the present invention will be described in detail.

In the present invention, examples of the wood material include raw wood, bark, and core material, but are not limited thereto.
Further, the tree species is not limited.
In addition, regarding the shape, examples include, but are not limited to, a square, a chip, a powder and the like, but the length parallel to the length direction of the fiber is defined as the length, and the length is 10 to 35 mm. It is preferable to use a chip having a shape corresponding to a weight ratio of 15 to 30 mm and a thickness of 10 mm or less in a direction orthogonal to the length direction by 90% or more. Due to the chip shape, uniform infiltration is performed in the impregnation treatment, and the quality stability during production is excellent.

About the caustic soda aqueous solution which performs an impregnation process, it is a density | concentration of 0.1 mass percent or more of solid content. When the solid content is less than 0.1% by mass, sufficient elution into the impregnating liquid such as lignin is not obtained in the impregnation treatment, and the wood fibers are broken in advance and in the present defibrating process, and the length of the fine fibers is shortened. The bulk density of the evaluation sample increases, and dust generation increases.
Desirably, the aqueous sodium hydroxide solution to be impregnated has a solid content of 0.5 mass percent or more. When the solid content is less than 0.5 mass percent, the bulk density of the evaluation sample increases and dust generation increases.
More preferably, the aqueous sodium hydroxide solution to be impregnated has a solid content of 0.5 to 5 mass percent. When the solid content exceeds 5 mass percent, the elution into the impregnating liquid such as lignin is saturated in the impregnation treatment, and only caustic soda costs are increased, and the work load in terms of deleterious substances management is also increased.

  The moisture content of the wood material is set to 50 mass percent or more by the impregnation treatment. When it is less than 50 mass percent, the wood fiber is broken in the preliminary defibrating step, the bulk density of the evaluation sample is increased, and dust generation is increased.

A wood material having a water content of 50 mass percent or more by the impregnation treatment is pre-defibrated by a wet beating machine having a gap width of 2 to 4 mm. Desirably, the wood material is pre-defibrated by a wet beating machine together with an impregnating solution of 20 mass percent or more based on the solid content mass of the impregnated wood material. By adding an impregnating solution of 20% by mass or more, a lubrication action works between the wood materials being pre-defibrated and between the wood material and the inside of the wet beating machine, and the wood fibers are broken in the pre-defibration process. An evaluation sample that is suppressed and has a low bulk density is obtained.
The mass of the impregnating liquid added at the time of prior defibration is more desirably 100 mass percent or more with respect to the solid content mass of the impregnated wood material. By adding 100 mass percent or more of the impregnating liquid, breakage of the wood fibers in the preliminary defibrating process is further suppressed, and dust generation is suppressed in handling the evaluation sample.
Here, the solid content mass of the woody material is dried by a method according to JIS-Z2101, and the mass in a state where the measured mass becomes constant is defined as the solid content mass in the present invention. If the mass change is 0.5% or less in accordance with JIS-Z2101 and measured at intervals of 6 hours, it is regarded as the solid content mass.

  The method for producing fine fibers for a wooden heat insulating material according to the present invention is characterized by performing multistage defibration. The multistage defibration in the present invention is to perform a defibration process in multiple stages of pre-defibration using a wet-type pulverizer and main defibration using a dry-type pulverizer. Compared with single-stage defibrating process using only wet pulverizer or single-stage defibrating process using dry-type pulverizer, the effect of reducing bulk density and suppressing dust generation is achieved. To do.

The defibrated wood material is separated into wood fibers and impregnation liquid by squeezing or centrifuging. In addition, the wood fiber is washed, and the caustic soda that adheres is washed away.
When the water content becomes less than 50% by weight during washing, a treatment for further increasing the water content is performed, and a wood fiber having a water content of 50% by weight or more is dry-type beater with a gap width of 0.5 to 2 mm. To defibrate and dry to obtain fine fibers.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example 1
The cedar from which the bark has been removed is crushed into a chip shape having a mass ratio of 70% or more in a size range of 13 to 28 mm in length, 15 to 22 mm in width and 2 to 5 mm in thickness, and a solid content of 15 to 25 ° C. is 0. .Impregnated with 1% by weight aqueous caustic soda solution for 12 hours.
The wet beating of FIG. 2 together with a wood material E having a solid content of 500 grams impregnated to a water content of 50 mass percent and 500 grams of impregnating liquid F corresponding to 100 mass percent with respect to the solid mass of the impregnated wood material Pre-defibration with a machine (gap size 2 mm). By changing the height of the plate 11, the size of the gap with the rotor 12 is adjusted.
The impregnating solution was dewatered and separated, washed with running water and washed, and finally defibrated with the dry beating machine shown in FIG. The defibrated wood fiber G put into the hopper 21 is defibrated at a gap between a fixed plate 24 and a rotating plate 26 driven by a defibrating motor 25 by a feed screw 23 driven by a feed motor 22. It is discharged from the discharge port 27. The gap size was gradually reduced from 2 to 0.5 mm, and this defibration was performed.
The defibrated fine fiber is dried by ventilation so as not to become lumps, and the mass ratio of 1 g of polyester binder fiber (heat fusion temperature 110 ° C., 2.2 dtex × 5 mm) to 10 g of fine fiber is shown in FIG. Mixed in, suspended in the scattering container 33, sucked and collected with a net collecting tool 32 connected to a suction device 31, and left in a 120 ° C. dryer for 15 minutes to be thermally fixed. The evaluation sample of Example 1 was produced.

  The prepared sample was dropped vertically from 10 cm above the black cloth, and the amount of fine fibers dropped from the sample and adhered to the black cloth was visually observed. In the heat insulating material manufactured using the fine fibers produced according to the present invention, the amount of dust generated during construction and handling was assumed to correspond to the amount of fine fibers adhering to the black cloth, and the degree of dust generation was evaluated.

The degree of suppression of energy required in the production process of the fine fibers is shown as follows: ：: suppressed, ×: failed to suppress. (Double-circle) shall have the effect concerning this invention.
Organic components such as lignin eluted in the impregnation solution in the impregnation treatment were mixed with the black liquor in the chemical solution recovery step in pulp production, and thermal energy was recovered with a recovery boiler. The evaluation results are shown as the degree of thermal energy recovery: ◎: fully recovered, ○: a little recovered, ×: not much recovered. ◎ and ○ have the effects according to the present invention.
Assuming that the bulk density of the evaluation sample corresponds to the bulk density of the heat insulating material produced using the fine fibers according to the present invention, the lower the bulk density, the better the heat insulation. : Normal, x: High, and the evaluation result is shown. ◎ and ○ have the effects according to the present invention.
The amount of fine fibers dropped and dropped and adhered to the black cloth is evaluated by visual observation, and the evaluation results are shown as follows: ◎: low, ◯: normal, ×: high. ◎ and ○ have the effects according to the present invention.
The evaluation results are shown in Table 1.

Example 2
A heat insulating material sample of Example 2 was produced in the same manner as in Example 1 except that the concentration of caustic soda was changed to 0.5 mass percent. The evaluation results are shown in Table 1.

Example 3
A heat insulating material sample of Example 3 was produced in the same manner as in Example 1 except that the concentration of caustic soda was changed to 4 mass percent. The evaluation results are shown in Table 1.

Example 4
A heat insulating material sample of Example 4 was produced in the same manner as in Example 1 except that the concentration of caustic soda was changed to 5 mass percent. The evaluation results are shown in Table 1.

Example 5
A heat insulating material sample of Example 5 was produced in the same manner as in Example 1 except that the concentration of caustic soda was changed to 8 mass percent. The evaluation results are shown in Table 1.

Example 6
A heat insulating material sample of Example 6 was produced in the same manner as in Example 1 except that the moisture content of the wood material after the impregnation treatment was changed to 60 mass percent. The evaluation results are shown in Table 1.

Example 7
Implemented in the same manner as in Example 2 except that the amount of the impregnation liquid added at the time of prior defibration was changed to 50 grams corresponding to 10 mass percent with respect to the solid content mass of the impregnated wood material. The heat insulating material sample of Example 7 was produced. The evaluation results are shown in Table 1.

Example 8
Implemented in the same manner as in Example 2 except that the amount of the impregnation liquid to be put in advance defibration was changed to 100 grams corresponding to 20 mass percent with respect to the solid content mass of the impregnated wood material. The heat insulating material sample of Example 8 was produced. The evaluation results are shown in Table 1.

Comparative Example 1
A heat insulating material sample of Comparative Example 1 was produced in the same manner as in Example 1 except that the concentration of caustic soda was changed to 0.04 mass percent. The evaluation results are shown in Table 1.

Comparative Example 2
A heat insulating material sample of Comparative Example 2 was produced in the same manner as in Example 1 except that the moisture content of the wood material after the impregnation treatment was changed to 45 mass percent. The evaluation results are shown in Table 1.

Comparative Example 3
A heat insulating material sample of Comparative Example 3 was produced in the same manner as in Example 1 except that the wood material was softened using steam and the impregnation liquid was changed to water by pre-defibration. The evaluation results are shown in Table 1.

Comparative Example 4
A heat insulating material sample of Comparative Example 4 was produced in the same manner as in Example 1 except that the pre-defibration was not performed on the wood material after the impregnation treatment. The evaluation results are shown in Table 1.

Comparative Example 5
A heat insulating material sample of Comparative Example 5 was prepared in the same manner as in Example 1 except that this defibration was not performed after the prior defibration. The evaluation results are shown in Table 1.

  The manufacturing method of the fine fiber of this invention can be utilized for manufacture of the heat insulating material which uses a wood material as a main raw material. Further, by collecting and molding the fine fibers, it is possible to develop the cushioning material, the gap filling material, the leakage liquid absorbing material, the ignition material, the seedling material, the plant cultivation mat, the water retention layer material, and the filter.

A Wood material B Caustic soda aqueous solution C Wood fine fiber D Impregnation liquid E Impregnated wood material F Impregnation liquid G Pre-defamed wood fiber 1 Impregnation process 2 Pre-defibration process by wet beating machine 3 Pressing, centrifugal separation and water washing Separation and washing process 4 of wood fiber and impregnating liquid 4 Main defibrating process 5 by dry beating machine Drying process 6 Pulp manufacturing chemical recovery process 11 Plate 12 Rotor 21 Hopper 22 Feed motor 23 Feed screw 24 Fixed plate 25 Defibrillation motor 26 Rotating plate 27 Discharge port 31 Suction device 32 Net collection device 33 Spattering floating container 34 Stirring device 35 Spattering power source

Claims (2)

  In the fine fiber manufacturing method for a wooden heat insulating material using a wooden material as a main raw material, the water content of the wooden material is impregnated with an aqueous solution of caustic soda having a solid content of 0.1 mass percent or more so that the moisture content is 50 mass percent or more, A method for producing fine fibers for a wooden heat insulating material, characterized by obtaining fine fibers by performing multi-stage defibration by pre-defibration with a wet beating machine and main defibration with a dry type beating machine.   In the fine fiber manufacturing method for the wood heat insulating material which uses a wood material as a main raw material, 20 mass% or more of the caustic soda aqueous solution of Claim 1 with respect to the solid content mass of the impregnated wood material is combined with the wood material impregnated 2. The method for producing fine fibers for a wooden heat insulating material according to claim 1, wherein pre-defibration is performed by a wet beating machine.