KR101034603B1 - Method for fabricating agricultural waste particle and method for fabricating the particle - Google Patents

Abstract

PURPOSE: A method for fabricating agricultural waste particles is provided to ensure excellent compatibility with a wood resin paste using agricultural wastes such as cornstalk and millet stalk. CONSTITUTION: A method for fabricating agricultural waste particles comprises the steps of: washing and drying agricultural wastes; cutting agricultural wastes; alkalizing the cut agricultural wastes; salting the alkali-processed agricultural waste; compressing and extending the salt-treated agricultural wastes; drying the compressed and extended agricultural waste; and cutting the agricultural wastes.

Description

Method for manufacturing agricultural waste particles and method for manufacturing particle board using the same {Method for fabricating agricultural waste particle and method for fabricating the particle}

The present invention relates to a method for producing agricultural waste particles and a method for producing a particle board using the same, more specifically, using agricultural wastes such as corn or sorghum and excellent compatibility with the resin adhesive for wood, mechanical strength and The present invention relates to a method for producing agricultural waste particles having excellent physical properties, a particle board using the same, and a method for producing the same.

With the recent improvement in living standards, the enhancement of housing culture and health, various building materials, interior materials, and flooring materials are made from natural materials such as wood or petrochemical products. It is gradually being replaced by density fiberboard, particle board, etc., and therefore, there is an urgent need for the stable supply and demand of raw materials and the development of alternative raw materials as the use of wood materials increases.

Agricultural wastes include rice straw, straw, corn stalks, sorghum and barley straw, and are similar to wood raw materials, and are natural raw materials containing a large amount of lignocellulose, a complex of cellulose and lignin, which can replace wood raw materials. Has the potential to

However, until now, these agricultural wastes are mainly used as low value-added materials such as feed, mushroom cultivation, composting cost, or roof cover, and thus, there is an increasing need for research on recycling methods and product development that can generate high value. In addition, asbestos, rock wool, and glass fiber, which are used as sound absorbing and insulation materials for building interiors, have been pointed out in terms of harmful components and environmental pollution. The development of materials is increasingly required.

In view of the recycling of resources due to the lack of wood resources, studies have been actively conducted to replace wood particles with new lignocellulosic materials. Particle board (particle board) is the most eco-friendly product that can be recycled most efficiently, and the government is recognizing its importance, and GR (Good Recycling) item certification is being reviewed. Particleboard is a product made by processing ordinary wood or waste wood in the form of particles or chips by crushing method and then thermoforming by mixing an appropriate amount of adhesive. Therefore, lignocellulosic materials such as rice straw, straw, corn stalks, barley straw, etc. If a method is developed to produce agricultural waste particle board by mixing with resin resin for wood, it is possible to partially or completely replace the wood plate material as a material that can replace the wood raw material which is currently insufficient and create high added value. Is not only a raw material, but is also expected to contribute greatly to the recycling of agricultural waste.

However, most of the agricultural wastes above were not able to produce particle boards in place of waste wood alone. This is because most of the agricultural wastes belong to annual herbaceous plants, and the woody texture of the tissues is lower than that of the perennial herbaceous plants, which does not satisfy the mechanical and physical properties required by the particle board.

In addition, cornstalks and sorghum can not only have a very low compatibility with the wood adhesive resin due to inert lignin filling the outer skin layer or the cellulose, but also easily rot. Because.

The technical problem of the present invention for solving the above problems is a method of producing agricultural waste particles having excellent compatibility with the resin adhesive for wood, and excellent mechanical strength and physical properties using agricultural waste such as corn sorghum or sorghum An object of the present invention is to provide a particle board and a manufacturing method thereof.

In order to solve the technical problem of the present invention as described above, the method for producing agricultural waste particles of the present invention comprises the steps of cutting the agricultural waste; Alkali treating the cut agricultural waste; Salt treating the alkali treated agricultural waste; Compressing and stretching the salt-treated agricultural waste; And drying the compressed and tensioned agricultural waste.

The method may further include washing and drying the agricultural waste before cutting the agricultural waste.

Cutting the agricultural waste is cut to a length of 1.5 cm to 2.5 cm when the agricultural waste is used for the inner layer of the particle board, and cut to 1 cm or less when the agricultural waste is used for the surface layer of the particle board. can do.

The alkali treatment step may be performed using an alkaline solution in a range of 100 ° C. or higher and pH 9 to pH 14.

The salt treatment step is 100 ℃ or more, it can be carried out using a solution in which the acid salt in which the normal concentration of the acid ions corresponding to the normal concentration of the alkali ions of the alkaline solution is dissolved.

In the drying step, the water content is 8% or less in the case of the agricultural waste material for the surface layer, and the water content is 3% or less in the case of the agricultural waste material for the inner layer.

In addition, the production method of the particle board using the agricultural waste particles of the present invention comprises the steps of applying a resin adhesive on the surface of the agricultural waste particles; And uniformly dispersing, distributing, heating, and pressing the agricultural waste particles in the mat forming apparatus.

The step of applying the resin adhesive may be applied to the surface of the agricultural waste particles 10 to 15 parts by weight of the amino-based urea resin adhesive with respect to 100 parts by weight of agricultural waste particles.

Uniformly distributing, heating, and pressurizing the agricultural waste particles may be a pressure of 30 to 40 kgf / cm 2, a heating temperature of 200 to 220 ° C., and a thermal pressure time of 8 to 10 seconds / mm.

The method may further include supplying the agricultural waste particles coated with the resin adhesive to a mat forming apparatus before heating and pressing the dispersed and distributed agricultural waste particles.

As described above, according to the present invention, the present invention is excellent in compatibility with the resin adhesive for wood using agricultural wastes, such as corn or sorghum, and a method for producing agricultural waste particles having excellent mechanical strength and physical properties and using the same Particle boards and methods for manufacturing the same can be provided.

In addition, the present invention manufactures a particle board using agricultural waste as raw materials, the cost reduction factor occurs in the furniture industry, building materials industry, etc., which further enhances the price competitiveness in the domestic and overseas markets to create high profits It is possible.

Hereinafter, the present invention will be described in detail.

The method for producing the agricultural waste particles of the present invention

Iii) washing and drying the agricultural waste;

Ii) cutting the agricultural waste;

Iii) alkali treating the cut agricultural waste;

Iii) salt treating the alkali treated agricultural waste;

Iii) compressing and stretching the salted agricultural wastes; And

Iii) drying the compressed and tensioned agricultural waste.

In addition, the method for producing a particle board using the agricultural waste particles of the present invention

Iii) applying a resin adhesive to the surface of the agricultural waste particles; And

Iii) uniformly dispersing, distributing, heating, and pressing the agricultural waste particles in the mat forming apparatus.

Hereinafter, a method for producing the agricultural waste particles of the present invention and a method for producing a particle board using the same will be described in more detail.

Agricultural waste particle  Produce

Corn and sorghum, which can be used as raw materials for agricultural waste particles, are annual herbaceous plants with rice plants and can grow for more than a few meters. These stems of corn and sorghum (corn and sorghum) grow straight without side branches, and are mainly used for livestock feed after fruit is harvested. Corn sorghum and sorghum are composed of many cellulosic tissues and lignin, which is sufficient for local activity. Lignin in particular accounts for 20% to 30% of the total weight. However, since the lignin is in an inactive state, the cellulosic tissue and the lignin material are not woody like the perennial wood, so it is difficult to use the reinforcing material.

Therefore, a pretreatment process is required to produce corn and sorghum into particles.

Iii) washing and drying agricultural waste

First, after the growth is completed, the leaves are removed from agricultural wastes such as cornstalks or sorghums, which have been confirmed, washed with water to remove foreign substances such as soil, and then dried.

Ii) cutting the agricultural waste

The washed and dried agricultural waste is cut to a certain length. At this time, the length to be cut depends on the area applied in the particle board. For example, the agricultural waste used for the inner layer of the particle board is cut to a length of 1.5 cm to 2.5 cm, and the agricultural waste used for the surface layer of the particle board is cut to a length of 1 cm or less.

Iii) alkali treating the cut agricultural waste.

After cutting the agricultural waste, the cut agricultural waste is subjected to alkali treatment. The alkali treatment is carried out using an alkaline solution in the range of pH 9 to pH 14, 100 ℃ or more. For example, it is performed using 0.5N to 2N sodium hydroxide solution. The sodium hydroxide solution is impregnated with the cut agricultural waste for about 1 hour. Meanwhile, in the present invention, sodium hydroxide solution was used as the solution used for alkali treatment, but the present invention is not limited thereto, and the solution will be satisfactory if the solution exhibits alkali characteristics such as sodium hypochlorite. In addition, the alkali treatment time may vary depending on the growth of agricultural waste such as corn or sorghum.

Iii) salt treating the alkali treated agricultural waste

After the alkali treatment, the alkali treated agricultural waste is salt treated. At this time, the salt treatment is a solution in which the normal concentration of acidic ions corresponds to the normal concentration of alkali ions of the alkali solution, for example, a solution in which 5 parts by weight or less of salt is added to 100 parts by weight of water is 100 ° C. or more. Keep it as it is. The salt may be at least one selected from sulfites, such as calcium sulfite salts and magnesium sulfite. On the other hand, salt treatment time should be appropriately performed according to the growth of agricultural waste such as corn or sorghum.

Iii) compressing and stretching the salted agricultural wastes

After the salt treatment, the salt-treated agricultural waste is compressed and tensioned. The pressing and pulling is performed by passing the salt-treated agricultural waste through a rolled pressing press with a continuous conveyor.

Iii) drying the compressed and stretched agricultural waste

The compressed and pulled agricultural waste is put into a screw-type hot air dryer, and the agricultural waste for surface layer is dried at a water content of 8 wt% or less and the inner layer agricultural waste at 3 wt% or less to produce agricultural waste particles.

The agricultural waste particles as described above are present in a state in which lignin present therein is activated to cause a polycondensation reaction with the resin resin for wood, thereby improving compatibility between the resin adhesive and the agricultural waste particles.

Agricultural waste Particles  Used particle  Manufacture of board

Iii) applying a resin adhesive to the surface of the agricultural waste particles

The resin adhesive is uniformly applied to the agricultural waste particles produced by washing, drying, cutting, alkali treatment, salt treatment, pressing, pulling and drying using a high speed mixer. The resin adhesive is uniformly applied to the surface of the agricultural waste particles injected into the high speed mixer and sprayed and moved through the nozzle.

In this case, the resin adhesive used may be an amino-based urea resin that is widely used for wood. In addition, the resin adhesive may be applied to the surface of the agricultural waste particles in a ratio of 10 to 15 parts by weight based on 100 parts by weight of agricultural waste particles for the surface layer, 5 to 10 parts by weight based on 100 parts by weight of agricultural waste particles for the inner layer.

Iii) uniformly dispersing, distributing, heating and pressurizing the agricultural waste particles in the mat forming apparatus

The agricultural waste particles coated with the resin adhesive are fed to the mat forming apparatus. The agricultural waste particles to be supplied are supplied in the order of the surface layer, the inner layer, and the surface layer, so that the distribution of the agricultural waste particle particles, the thickness of the mat, and the like can be constantly controlled.

Then, the agricultural waste particles to which the resin adhesive is applied are uniformly dispersed and distributed in a mat forming apparatus, using a hot pressure press apparatus at a pressure of 30 to 40 kg / cm 2, a heating temperature of 200 to 220 ° C., and a thermal pressure time of Molding is performed at a condition of 8 to 10 seconds / mm to allow the resin adhesive to cure to produce the particle board of the present invention. At this time, since the amino-based urea resin used as the resin adhesive is a thermosetting resin, thermosetting molding is performed.

The particle board manufactured as described above improves the compatibility between the resin adhesive and the agricultural waste particles due to the polycondensation reaction between the lignin and the resin adhesive inside the agricultural waste particles, thereby improving the physical mechanical properties of the particle board. You can expect

Hereinafter, preferred examples are provided to aid the understanding of the present invention. However, the following experimental examples are only for helping understanding of the present invention, and the present invention is not limited to the following experimental examples.

Experimental Example 1

After removing the mouth of the corn stalks which had been completely grown, they were washed to remove foreign substances such as soil and dried. The cornstalks were then cut to a length of 2 cm for the inner layer and 1 cm for the surface layer. The cut cornstalks were alkali treated with 1N sodium hydroxide solution at pH 10, 100 ° C. for 1 hour. Alkali treated cornstalks were salted for 1 hour using 100 ° C. 1N calcium sulfite salt solution. Salt-treated cornstalks were pressed through a roll-type press with a continuous conveyor, and cornstalk particles having a water content of 8% for the surface layer and 3% for the inner layer were prepared using a hot air dryer.

Of the above-mentioned corn cob particles, 10 kg of surface corn cob particles were coated with 1.2 kg of urea resin with a resin resin for wood, and 0.8 kg of urea resin was applied to 10 kg of corn cob particles for inner layer using a high-speed mixer. After spraying the cornstalk particles in the order of surface layer, inner layer, and surface layer, the particle board was molded at a thermostatic pressure of 40 kg / cm 2, temperature 200 ° C., and 10 seconds / mm using a hot press. And prepared.

Experimental Example 2

Particle boards were prepared through the same procedure as in Example 1, except that corn cobs were replaced by millet.

Comparative Example 1

A particle board was prepared through the same procedure as in Example 1, except that alkali treatment and salt treatment of corn cob were not performed.

Comparative Example 2

Particle boards were prepared through the same procedure as in Comparative Example 1, except that corn cobs were replaced by millet.

Comparative Example 3

Particle board was prepared through the same procedure as in Example 1 except that the corn cob particles were replaced with general waste wood.

Table 1 below is a table measuring the mechanical and physical properties of the particle board prepared through Experimental Examples 1 and 2, Comparative Examples 1 to 3 described above. At this time, the mechanical properties were performed using a UTM (Universal Testing Machine) strength test equipment.

In addition, the physical properties are measured by using a density meter, a moisture meter, the thickness expansion rate according to the moisture absorption was measured by the method of immersion in room temperature for 24 hours.

Result of mechanical and physical properties of particle board Kinds density
(g / cm3) Moisture content
(%) Flexural strength (N / mm2) Absorption thickness
Expansion rate
(%) Peel strength
(N / mm2) Screw holding force
(N) Vertical horizontal plane side Experimental Example 1 0.67 5.3 25.8 7 1.0 912 468 Experimental Example 2 0.7 4.6 27.3 6 1.2 945 471 Comparative Example 1 0.78 5.5 14.7 10 0.5 573 255 Comparative Example 2 0.78 6.2 16.4 8.5 0.6 638 313 Comparative Example 3 0.72 5.5 18.3 8 0.8 768 405

Referring to Table 1, the physical and mechanical properties of Experimental Example 1 and Experimental Example 2, which are manufactured according to the method of manufacturing the particle board of the present invention, in particular, using corn and sorghum treated with alkali treatment and salt treatment, are general. It can be seen that the particle board manufactured using waste wood, that is, superior to Comparative Example 3.

In addition, it can be seen that Comparative Example 1 and Comparative Example 2, which are not subjected to alkali treatment and salt treatment, have lower physical and mechanical properties than Comparative Example 3 as well as Experimental Example 1 and Example 2.

Therefore, in the case of producing particle boards using agricultural wastes such as corn or sorghum, it is necessary to carry out alkali treatment and salt treatment, as in the present invention, to produce agricultural waste particles in which the compatibility of the resin adhesive for wood is improved. It can be seen that, according to the thermo-formed particle board is excellent in physical and mechanical properties.

Table 2 below is a table comparing the bending strength of Experimental Example 1 and Experimental Example 2, Comparative Example 1 and Comparative Example 2 and Comparative Example 3.

Flexural strength comparison Kinds Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Flexural strength (N / ㎡) 25.8 27.3 14.7 16.4 18.3 Comparison with Comparative Example 3 + 41% + 49% -20% -10% 0%

Referring to Table 2, Experimental Example 1 and Experimental Example 2, which are manufactured according to the particle board manufacturing method of the present invention, in particular, using corn and sorghum treated with alkali treatment and salt treatment, are all compared with Comparative Example 3. It can be seen that the flexural strength is improved by 40% or more. This is presumably because the adhesion between the resin adhesive and agricultural waste is improved by the lignin of corn and sorghum.

On the other hand, unlike the present invention, Comparative Examples 1 and 2, which are not subjected to alkali treatment and salt treatment, can be seen that the flexural strength is lowered.

Table 3 below is a table comparing the peel strength of Experimental Example 1 and Experimental Example 2, Comparative Example 1 and Comparative Example 2 and Comparative Example 3.

Peel Strength Comparison Kinds Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Peel strength
(N / mm2) One 1.2 0.5 0.6 0.8 Comparison with Comparative Example 3 + 25% + 50% -38% -25% 0%

Referring to Table 3, Experimental Example 1 and Experimental Example 2, which are manufactured according to the particle board manufacturing method of the present invention, in particular, using corn and sorghum treated with alkali treatment and salt treatment, are all peeled compared to Comparative Example 3. It can be seen that the strength is improved by more than 25%. In particular, it can be seen that the peel strength of 50% was improved in Example 2 using a millet. This is presumably because the bond strength between the resin adhesive and the agricultural waste is improved by the lignin of cornstalks and millets, similar to the flexural strength.

Table 4 below is a table comparing the screw holding force of Experimental Example 1 and Experimental Example 2, Comparative Example 1 and Comparative Example 2 and Comparative Example 3.

Screw Holding Force Comparison Kinds Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Screw holding force
(N) plane side plane side plane side plane side plane side Experimental value 912 468 945 471 573 255 638 313 768 405 Comparative Example 3
compare + 19% + 16% + 23% + 16% -25% -37% -17% -23% 0% 0%

Referring to Table 4, Experimental Example 1 and Experimental Example 2, which are manufactured according to the particle board manufacturing method of the present invention, in particular, using corn and sorghum treated with alkali treatment and salt treatment, are all screwed compared to Comparative Example 3. It can be seen that the holding force increases by more than 19% in the plane and 16% in the side. That is, it can be seen that the screw holding force of the particle board using the agricultural waste, produced according to the method for producing a particle board of the present invention is excellent.

Table 5 below is a table comparing the water absorption thickness expansion ratio of Experimental Example 1 and Experimental Example 2, Comparative Example 1 and Comparative Example 2 and Comparative Example 3.

Moisture Absorption Thickness Expansion Rate Comparison Kinds Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Absorption thickness
% Expansion 7 6 10 8.5 8 Comparison with Comparative Example 3 -13% -25% 25% 6% 0%

Referring to Table 5, Experimental Example 1 and Experimental Example 2, which are manufactured according to the particle board manufacturing method of the present invention, in particular, using corn and sorghum treated with alkali treatment and salt treatment, are all moisture compared to Comparative Example 3. It can be seen that the absorption thickness expansion ratio is lower than 13%. In particular, in Experimental Example 2 prepared by using a soakdae is 25% low moisture absorption thickness expansion rate.

Therefore, since the moisture absorption thickness expansion rate of the particle board using agricultural waste is low, it can be seen that the physical properties of the particle board manufactured according to the method of manufacturing the particle board of the present invention are excellent.

As described above, the particle board using the agricultural waste particles produced by performing the alkali treatment and salt treatment of the particles produced by the agricultural waste particle production method of the present invention, that is, agricultural waste such as corn stalk or sorghum, is a general waste. Compared to the particle board using wood, it is excellent in compatibility with the resin resin for wood, it can be seen that the physical and mechanical properties are excellent.

Therefore, it is possible to produce particle boards with excellent physical and mechanical properties using cornstalks and sorghums produced in significant quantities around the world every year. Therefore, in the furniture industry, building materials industry, etc., cost reduction factors occur, thereby making it possible to further increase the price competitiveness in domestic and overseas markets, thereby generating high profits.

In addition, by reducing the use of timber raw materials in terms of the global environment, there is an additional effect of suppressing forest damage and suppressing carbon dioxide, the main culprit of global warming.

Claims (10)

Washing and drying the agricultural waste;
Cutting the agricultural waste;
Alkali treating the cut agricultural waste;
Salt treating the alkali treated agricultural waste;
Compressing and stretching the salt-treated agricultural waste; And
And drying the compressed and stretched agricultural waste.
The cutting of the agricultural waste may include cutting the agricultural waste to a length of 1.5 cm to 2.5 cm when the agricultural waste is used for the inner layer of the particle board, and cutting the agricultural waste to 1 cm or less when the agricultural waste is used for the surface layer of the particle board. When the agricultural waste material for the surface layer, the moisture content is 8% or less, and for the inner layer agricultural waste, the water content is 3% or less,
The alkali treatment step uses an alkaline solution in a range of 100 ° C. or higher and pH 9 to pH 14, and the salt treatment step is 100 ° C. or higher, and a normal concentration of acidic ions is applied to a normal concentration of alkali ions of the alkaline solution. Produce agricultural waste particles using a solution of the corresponding acid salt dissolved,
Applying a resin adhesive on the surface of the agricultural waste particle to the surface of the agricultural waste particle in an amount of 10 to 15 parts by weight of an amino urea resin adhesive based on 100 parts by weight of the agricultural waste particle; And
Supplying the agricultural waste particles coated with the resin adhesive to a mat forming apparatus;
In the mat forming apparatus, the agricultural waste particles are uniformly dispersed and distributed, and a pressure of 30 to 40 kgf / cm 2, a heating temperature of 200 to 220 ° C., and a thermal pressure time of 8 to 10 seconds / mm are heated and pressurized. A method for producing agricultural waste particle board, characterized in that the production.


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