CN113442254B - A kind of production method of reed particle board - Google Patents

Abstract

The invention provides a production method of a reed particle board, belonging to the technical field of plant-based composite material manufacture. The production method of the reed particle board comprises the following steps: removing leaves from reed straws, and then drying to obtain dry reed straws with leaves removed; spraying an aqueous solution of an activating agent on the surface of the dried and defoliated reed stalks, and processing the reed stalks into reed shavings after the aqueous solution of the activating agent is dried by the reed stalks; the mass concentration of the activator aqueous solution is 30-40%, the spraying amount of the activator aqueous solution is calculated by the weight of the activator, and the weight of the activator is 0.01-0.09% of the absolute dry weight of the dry reed leaves; adding a urea-formaldehyde adhesive into the reed shavings, paving the glued reed shavings into a plate blank, and carrying out hot pressing to obtain the reed shaving board. By adopting the method, the addition amount of the active agent can be reduced and the production cost can be reduced on the premise of using the low-price urea formaldehyde adhesive.

Description

A kind of production method of reed particle board

technical field

The invention relates to the technical field of plant-based composite material manufacturing, in particular to a method for producing reed particleboard.

Background technique

my country is a country with scarce forest resources, and its dependence on foreign wood exceeds 50%. Reed is a perennial aquatic or wet tall grass with well-developed rhizomes and tough stalks. Its chemical composition is similar to wood, including cellulose, hemicellulose and lignin. It is a high-quality raw material for the production of wood-based panels. China is rich in reed resources, with an area of more than 1.3×106hm ² . At present, reeds in my country are mainly used for papermaking, and there is a serious problem of waste water pollution in the papermaking process. Making full use of reed stalks instead of wood to produce wood-based panels can not only solve the problem of environmental pollution caused by reed papermaking, but also solve the problem of contradiction between supply and demand of wood materials in my country. However, the surface of the reed stem is smooth, and more than 90% of the silicified cells and waxy layers of the reed stem are distributed in the surface layer. These silicified cells and wax layers have low surface free energy and poor activity. It is difficult to obtain good bonding results with urea-formaldehyde adhesives (UF). Although isocyanate adhesives can achieve good bonding strength, isocyanate adhesives The price of the urea-formaldehyde adhesive is 8 to 10 times that of the urea-formaldehyde adhesive, and the production cost is high. To use urea-formaldehyde adhesive to prepare reed particle board with high bonding strength, it is necessary to use surfactant to modify reed particle board. The usual modification treatment method is to add a certain amount of activator and adhesive to the processed reed shavings by sizing to improve the activity and gluing performance of the reed shavings, and then heat the modified shavings through hot pressing. Shaped to prepare reed particleboard. This method adds a large amount of active agent, which also increases the production cost of reed particleboard to a certain extent.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a method for producing reed particleboard, and the method of the present invention can reduce the addition amount of active agent and reduce production cost under the premise of using cheap urea-formaldehyde adhesive.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

The invention provides a production method of reed particleboard, comprising the following steps:

Defoliation of the reed stalks, and then drying to obtain dry defoliated reed stalks;

The activator aqueous solution is sprayed on the surface of the dry defoliated reed stalks, and after the activator aqueous solution is absorbed by the reed stalks, the reed stalks are processed into reed shavings; the mass concentration of the activator aqueous solution is 30-40%, and the activated The spraying amount of the aqueous solution is based on the weight of the activator, and the weight of the activator is 0.01-0.09% of the absolute dry weight of the dry defoliated reed stalk;

A urea-formaldehyde adhesive is added to the reed shavings, the reed shavings after sizing are paved into slabs, and after hot pressing, a reed particle board is obtained.

Preferably, the drying temperature is 90-100° C., and the defoliated reed stalks are in an absolutely dry state after drying.

Preferably, when the activator aqueous solution is sprayed, the temperature of the drying defoliated reed stalks is 30-40°C.

Preferably, the activator in the activator aqueous solution includes one or more of fatty acid methyl ester ethoxylate, carboxylic acid and sodium dodecylbenzenesulfonate.

Preferably, in the process of spraying the activator aqueous solution, the reed rod is turned while spraying.

Preferably, the equipment used for spraying the aqueous activator solution is a spray gun, and the pressure of the spray gun is 0.8 MPa.

Preferably, the particle size of the reed shavings is 20-60 mesh.

Preferably, the sizing amount of the urea-formaldehyde adhesive is 12-13% of the absolute dry weight of the dry defoliated reed.

Preferably, the temperature of the hot pressing is 160-170°C.

Preferably, the hot pressing time is 30-40 s/mm.

The invention provides a method for producing reed particleboard, comprising the following steps: removing leaves from reed stalks, and then drying them to obtain dry defoliated reed stalks; After the aqueous solution is sucked dry by the reed rod, the reed rod is processed into reed shavings; the mass concentration of the activator aqueous solution is 30-40%, and the spray amount of the activator aqueous solution is based on the weight of the activator, and the amount of the activator The weight is 0.01-0.09% of the absolute dry weight of the defoliated reed stalks; urea-formaldehyde adhesive is added to the reed shavings, the sizing reed shavings are paved into slabs, and after hot pressing, reed particle boards are obtained.

In the present invention, the activating agent is directly applied on the surface of the reed shavings before the preparation of the reed shavings. Compared with the conventional method of adding the activating agent to the processed reed shavings through sizing after mixing the activating agent and the adhesive, the invention can not only achieve obvious The modification effect can be improved, and the dosage of active agent can be significantly reduced, and the production cost of reed particleboard is also reduced accordingly.

Further, in the present invention, by drying the defoliated reed stalks at 90-100 ℃ to absolutely dry, the surface of the reed stalks will produce certain shrinkage and micro-cracks, and spray the activator aqueous solution when the temperature is kept at 30-40 ℃, which helps The silicified cells and wax layer on the surface of the reed stalk evenly absorb the activator, which increases the effect of activation and modification.

Detailed ways

The invention provides a production method of reed particleboard, comprising the following steps:

Defoliation of the reed stalks, and then drying to obtain dry defoliated reed stalks;

The activator aqueous solution is sprayed on the surface of the dry defoliated reed stalks, and after the activator aqueous solution is absorbed by the reed stalks, the reed stalks are processed into reed shavings; the mass concentration of the activator aqueous solution is 30-40%, and the activated The spraying amount of the aqueous solution is based on the weight of the activator, and the weight of the activator is 0.01-0.09% of the absolute dry weight of the dry defoliated reed stalk;

A urea-formaldehyde adhesive is added to the reed shavings, the reed shavings after sizing are paved into slabs, and after hot pressing, a reed particle board is obtained.

In the present invention, without special instructions, the raw materials used are all commercially available commodities well known in the art.

In the present invention, the reed straw is defoliated and then dried to obtain a dry defoliated reed stalk.

The present invention does not have any special limitation on the reed straw, and the reed straw from well-known sources in the art can be used. The present invention has no special requirements on the defoliation process of the reed straw, and the defoliation process well known in the art can be used.

In the present invention, preferably, the defoliated reed straws are bundled and sent to a drying kiln for drying. In the present invention, the drying temperature is preferably 90 to 100°C, more preferably 92 to 96°C. The present invention has no special requirements on the drying time, and it is preferable to make the dried defoliated reed stalks in an absolutely dry state.

The invention controls the drying temperature within the above range, so that certain shrinkage and micro-cracks are generated on the surface of the reed stem, which is beneficial to the subsequent uniform absorption of the activator by the silicified cells and the waxy layer on the surface of the reed stem.

After the dried defoliated reed stalks are obtained, the present invention sprays the activator aqueous solution on the surface of the dried defoliated reed stalks, and after the activator aqueous solution is absorbed by the reed stalks, the reed stalks are processed into reed shavings; the quality of the activator aqueous solution is The concentration is 30-40%, and the spraying amount of the activator aqueous solution is based on the weight of the activator, and the weight of the activator is 0.01-0.09% of the absolute dry weight of the dry defoliated reed stalks.

In the present invention, the activator in the activator aqueous solution preferably includes one or more of fatty acid methyl ester ethoxylate, carboxylic acid and sodium dodecylbenzenesulfonate; when the activator includes the above When there are many kinds of substances, the present invention has no special requirements for the ratio of each activator, and any ratio can be used. In the present invention, the carboxylic acid is preferably a monocarboxylic acid. The present invention has no special requirements on the specific type of the monocarboxylic acid, and any monocarboxylic acid well known in the art can be used, such as formic acid, acetic acid, and o-toluic acid.

In the present invention, the mass concentration of the activator aqueous solution is preferably 32-38%, more preferably 34-36%. In the present invention, the weight of the activator is preferably 0.02-0.08%, more preferably 0.03-0.07%, of the absolute dry weight of the dry defoliated reed stalks.

When the activator aqueous solution is sprayed, the temperature of the dried defoliated reed stalk is 30-40°C.

The present invention preferably uses a spray gun to spray the activator aqueous solution, and the pressure of the spray gun is preferably 0.8MPa.

In the present invention, when spraying the activator aqueous solution, the temperature of the drying defoliated reed stalks is preferably 30-40°C, more preferably 32-38°C. The present invention controls the temperature of the drying and defoliated reed stalks within the above range, which helps the silicified cells and wax layers on the surface of the reed stalks to absorb the activating agent uniformly and increases the activation and modification effect.

In the present invention, it is preferable to turn the reed stem while spraying the activator aqueous solution, so as to ensure that the activator aqueous solution is sprayed on all surfaces of the reed stem.

After the activator aqueous solution is sucked dry by the reed stem, the present invention processes the reed stem into reed shavings.

The present invention has no special requirements on the processing process of the reed shavings, and a mechanical processing process well known in the art can be used.

In the present invention, the particle size of the reed shavings is preferably 20-60 mesh, more preferably 30-50 mesh.

After the reed shavings are obtained, the present invention adds a urea-formaldehyde adhesive to the reed shavings, and the sizing reed shavings are paved into slabs and hot-pressed to obtain reed particle boards.

In the present invention, the sizing amount of the urea-formaldehyde adhesive is preferably 12-13%, more preferably 12.2-12.8%, and even more preferably 12.4-12.6% of the absolute dry weight of dry reed reed. The present invention preferably applies the urea-formaldehyde adhesive by means of a ring mixer.

After sizing, in the present invention, the sizing reed shavings are paved into slabs, and after hot pressing, the reed shavings board is obtained.

The present invention has no special requirements on the size of the slab, which can be set according to actual needs.

In the present invention, the temperature of the hot pressing is preferably 160-170°C, more preferably 162-168°C, and further preferably 164-166°C; the hot-pressing time is preferably 30-40s/mm, more preferably It is 32-38 s/mm, More preferably, it is 34-36 s/mm. In the present invention, the hot pressing time refers to the hot pressing time required per millimeter of thickness of the slab.

In the present invention, the density of the reed particleboard obtained after hot pressing is preferably 0.7 to 0.8 g/cm ³ .

The production method of the reed particleboard provided by the present invention will be described in detail below in conjunction with the examples, but they should not be construed as limiting the protection scope of the present invention.

Example 1

1. Defoliate the reed straw, bundle it into a bundle and send it to a drying kiln, dry it at 90°C to an absolute dry state, then take out the dried defoliated reed stalk, cool it to 40 ℃, and obtain a dry defoliated reed stalk;

2. Adjust the non-ionic activator fatty acid methyl ester ethoxylate into an aqueous solution with a mass concentration of 30%, spray it evenly on the surface of the dry defoliated reed stem at 40°C, and turn the reed stem while spraying to ensure the activator. The aqueous solution is sprayed on all surfaces of the reed stalk, and the spraying amount is controlled so that the dosage of the activator is 0.15% of the absolute dry weight of the defoliated reed stalk;

3. After the activator aqueous solution is sucked dry by the reed rod, the reed rod is sent to mechanical processing to be processed into 30 mesh reed shavings;

4. The urea-formaldehyde adhesive is applied to the reed shavings through a ring glue mixer, and the sizing amount is 13% of the absolute dry weight of the dry defoliated reed stalks;

5. The glued reed shavings are paved into slabs through a mechanical paving machine, and then sent to a hot press for hot pressing. The hot pressing temperature is 170 ° C, and the hot pressing time is 30s/mm, and the reed particle board is finally obtained. , the density of reed particleboard is 0.75g/cm ³ .

Comparative Example 1

The difference from Example 1 is that first, the reed rods are pulverized into reed shavings by a pulverizer, and then the activator and the adhesive are evenly mixed, and the activator and the adhesive mixture are sprayed to the processed reed shavings. In addition, the activator is added through the sizing process, and the rest are the same as in Example 1.

Example 2

1. Defoliate the reed straws, bundle them into bundles and send them to a drying kiln, dry them at 100°C to a dry state, then take out the dried defoliated reed stalks and cool them to 30°C to obtain dry defoliated reed stalks;

2. The anionic activator acetic acid was adjusted into an aqueous solution with a mass concentration of 40%, and sprayed evenly on the surface of the dry defoliated reed stem at 30°C with a spray gun. The amount of spraying is controlled at 0.1% of the absolute dry weight of the dry defoliated reed stalks;

3. After the activator aqueous solution is sucked dry by the reed rod, the reed rod is sent to mechanical processing to be processed into 40 mesh reed shavings;

4. The urea-formaldehyde adhesive is applied to the reed shavings through a ring glue mixer, and the sizing amount is 12% of the absolute dry weight of the dry defoliated reed sticks;

5. The glued reed shavings are paved into a slab of a certain thickness by a mechanical paving machine, and then sent to a hot press for hot pressing. The hot pressing temperature is 160 ° C, and the hot pressing time is 35s/mm. A reed particle board was obtained, and the density of the reed particle board was 0.75 g/cm ³ .

Example 3

1. Defoliate the reed straws, bundle them into bundles and send them to a drying kiln, dry them at 100°C to a dry state, then take out the dried defoliated reed stalks and cool them to 30°C to obtain dry defoliated reed stalks;

2. Adjust the anionic activator sodium dodecyl benzene sulfonate into an aqueous solution with a mass concentration of 35%, spray it on the surface of the dry defoliated reed stalk at 30°C with a spray gun, and turn the reed stalk while spraying to ensure the activator. The aqueous solution is sprayed on all surfaces of the reed stalks, and the spraying amount is controlled so that the dosage of the activator is 0.2% of the absolute dry weight of the defoliated reed stalks;

3. After the activator aqueous solution is sucked dry by the reed rod, the reed rod is sent to mechanical processing to be processed into 40 mesh reed shavings;

4. The urea-formaldehyde adhesive is applied to the reed shavings through a ring glue mixer, and the sizing amount is 13% of the absolute dry weight of the dry defoliated reed stalks;

5. The glued reed shavings are paved into a slab of a certain thickness by a mechanical paving machine, and then sent to a hot press for hot pressing. The hot pressing temperature is 165°C, and the hot pressing time is 40s/mm. A reed particle board was obtained, and the density of the reed particle board was 0.8 g/cm ³ .

Example 4

The difference from Example 1 is that it was dried to an absolute dry state at 80°C.

Example 5

The difference from Example 1 is that the surface of the dry defoliated reed stalks at 25°C was evenly sprayed with a spray gun.

With reference to the GB/T4897.2-2003 standard, performance tests were carried out on the reed particleboards of Examples 1 to 5 and Comparative Example 1, and the results are shown in Table 1.

Table 1 Properties and activator dosage of particleboards of Examples 1 to 5 and Comparative Example 1

As can be seen from the results of Examples 1 to 5 and Comparative Example 1 in Table 1, the present invention directly applies the active agent on the surface of the reed stalks before the preparation of the reed shavings, and mixes the active agent and the sizing agent for processing by sizing. Compared with the conventional method of adding activator to good reed shavings, it can not only achieve obvious modification effect, but also can significantly reduce the amount of activating agent, thereby reducing the production cost of reed particleboard. In addition, by comparing the results of Example 1 and Example 4, it can be found that in Example 1 of the present invention, by drying the defoliated reed stalks at 90-100° C. to absolutely dry, the surface of the reed stalks will have certain shrinkage and microscopic Therefore, the activation modification effect is better, so that the bonding strength of the particleboard of Example 1 is better than that of Example 4. From the results of Example 1 and Example 5, it can be seen that the present invention has a better activation modification effect at 40°C (Example 1) by spraying the activator at 40°C than at 25°C, and the obtained particleboard combines higher strength.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (9)

1. a production method of reed particleboard, is characterized in that, comprises the following steps: The reed straw is defoliated and then dried to obtain a dry defoliated reed stalk; the drying temperature is 90-100° C., and the defoliated reed stalk is in an absolutely dry state after drying; The activator aqueous solution is sprayed on the surface of the dry defoliated reed stalks, and after the activator aqueous solution is absorbed by the reed stalks, the reed stalks are processed into reed shavings; the mass concentration of the activator aqueous solution is 30-40%, and the activated The spraying amount of the aqueous solution is based on the weight of the activator, and the weight of the activator is 0.01-0.09% of the absolute dry weight of the dry defoliated reed stalk; A urea-formaldehyde adhesive is added to the reed shavings, the reed shavings after sizing are paved into slabs, and after hot pressing, a reed particle board is obtained. 2 . The production method according to claim 1 , wherein, when the activator aqueous solution is sprayed, the temperature of the dried defoliated reed stalk is 30-40° C. 3 . 3. production method according to claim 1, is characterized in that, the activator in described activator aqueous solution comprises a kind of in fatty acid methyl ester ethoxylate, carboxylic acid and sodium dodecylbenzenesulfonate or variety. 4. The production method according to claim 1, wherein in the process of spraying the activator aqueous solution, the reed rod is turned while spraying. 5 . The production method according to claim 1 , wherein the equipment used for spraying the aqueous activator solution is a spray gun, and the pressure of the spray gun is 0.8 MPa. 6 . 6 . The production method according to claim 1 , wherein the particle size of the reed shavings is 20-60 meshes. 7 . 7 . The production method according to claim 1 , wherein the sizing amount of the urea-formaldehyde adhesive is 12-13% of the absolute dry weight of the dry defoliated reed. 8 . 8 . The production method according to claim 1 , wherein the temperature of the hot pressing is 160-170° C. 9 . 9 . The production method according to claim 8 , wherein the time of the hot pressing is 30-40 s/mm. 10 .