CN110744649A - Anti-cracking low-aldehyde multi-layer eucalyptus board and production method thereof - Google Patents

Abstract

The invention provides an anti-cracking low-aldehyde multi-layer eucalyptus board and a production method thereof. The production method of the multi-layer board comprises veneer sheet sorting, sheet gluing, cold pressing, hot pressing, standing for curing and scraping dust, The steps of sanding, repairing, trimming and veneering, which are characterized by spraying a cured film around and on the upper and lower surfaces of the slab before the first hot pressing and the last hot pressing to protect the glue from passing through the hot pressing process. It dries quickly and maintains the internal stress of the multi-layer board. It can also make the urea-formaldehyde glue fully react, so that the formed multi-layer board is not easy to crack. The user's use process reduces the volatile formaldehyde. After sanding and veneering, it can be sawed and packaged to obtain crack-resistant low-aldehyde multi-layer eucalyptus board products.

Description

Anti-cracking low-aldehyde multi-layer eucalyptus board and production method thereof

technical field

The invention relates to a multi-layer wood board and a production method thereof, in particular to a crack-resistant low-aldehyde multi-layer eucalyptus wood board and a production method thereof.

Background technique

The multi-layer board is a multi-layer board material made of wood segments that are cut into veneers or sliced into veneers, and then glued with adhesives. Usually, the fiber directions of adjacent layers of veneers are glued perpendicular to each other. The outside is veneered or not veneered as needed, also known as plywood.

Multi-layer wood is one of the commonly used materials for furniture, one of the three major wood-based panels, and can also be used for aircraft, ships, trains, automobiles, buildings and packaging boxes. Usually, the surface plate and the inner layer are symmetrically arranged on both sides of the center layer or the core. It is a slab made of glued veneers crisscrossed in the direction of the wood grain, and pressed under the condition of heating or no heating. The number of layers is generally odd, and a few are even. The physical and mechanical properties in the vertical and horizontal directions are slightly different. Commonly used plywood types are three plywood and five plywood, and there are currently more than seven layers. Plywood can improve the utilization rate of wood and is a main way to save wood. The main tree species are: beech, camphor, willow, poplar, eucalyptus and so on.

In order to improve the anisotropic properties of natural wood as much as possible, so that the properties of plywood are uniform and the shape is stable, generally plywood must comply with two basic principles in structure: one is symmetry; the other is that adjacent layers of veneer fibers are perpendicular to each other. The principle of symmetry is that the veneers on both sides of the symmetrical center plane of the plywood should be symmetrical to each other regardless of the nature of the wood, the thickness of the veneer, the number of layers, the direction of the fibers, and the moisture content. In the same plywood, veneers of a single species and thickness can be used, or veneers of different species and thicknesses can be used; however, any two layers of veneer that are symmetrical to each other on both sides of the symmetrical center plane must be of the same species and thickness. The front and back panels are not allowed to be of the same tree species.

In order to make full and rational use of forest resources to develop plywood production and make the best use of materials, the newly formulated national standard in my country divides plywood into plywood for painting (for furniture and sewing machine tables that need to be painted with transparent paint) according to the use of plywood. panels and various electrical enclosures and other products), plywood for decoration (used as decoration materials for buildings, furniture, vehicles and ships, floors), plywood for general use (for packaging, padding and other purposes) and veneer decorative plywood ( Used as a high-grade decorative material for buildings, furniture, vehicles, ships, etc.).

In recent years, Guangdong and Guangxi, Yunnan, Fujian, Guizhou, Hainan and other provinces in southern my country have begun to introduce fast-growing eucalyptus species cultivated by the state-owned Dongmen Forest Farm in Guangxi. The sapwood layer is relatively broad, white to pale pink; the heartwood is slightly brownish red. At present, fast-growing eucalyptus grows fast and can become a talent in 3 years. Farmers in mountainous areas plant a large number of them, which have accounted for more than 50% of the available wood in the south. In addition, the original tree species such as pine, fir, neem and other trees grow slowly, and it is not a natural forest. It can be cut down again, and the wood output of 1 mu of fast-growing eucalyptus is equivalent to the output of more than 5 mu of natural forest.

Eucalyptus only accounts for 13.7% of Guangxi's forest area, but it meets more than 80% of Guangxi's and more than 20% of the country's wood demand. At present, my country has successfully developed high-performance eucalyptus reconstituted lumber, eucalyptus veneer laminated lumber, bamboo eucalyptus composite materials, thick-core eucalyptus solid wood composite boards and formaldehyde-free eucalyptus plywood manufacturing technology, etc. The application of eucalyptus in wood-based panels increasingly popular.

The core layer of the solid wood composite multi-layer board is mostly made of eucalyptus single sheet through adhesive pressing. Eucalyptus is a general term for Eucalyptus plants in the Myrtaceae family. Eucalyptus has strong adaptability and can grow in poor soil with fast growth and low maintenance costs, so the planting area is increasing year by year. Eucalyptus wood is red, shiny, no special odor, interlaced texture, dense structure, hard and heavy material, easy to bend. Eucalyptus with larger diameter grades is cut into veneer by rotary cutting and used as core board to produce plywood or laminated veneer lumber, while eucalyptus with small diameter grade, branch wood or difficult rotary cutting is processed into wood chips for papermaking or production of fiberboard, so eucalyptus The comprehensive utilization rate can be increased to more than 90%.

The applicant, Guangxi Hengxian Zhenglin Wood Industry Co., Ltd. is currently a manufacturer of solid wood composite multi-layer boards. Eucalyptus wood composite panels with less formaldehyde and high strength, suitable for decoration materials of buildings, furniture, vehicles and ships, have also applied for a number of Chinese patents, such as:

[1] The method for producing all-eucalyptus plywood by using the compound urea-formaldehyde resin for insect and mildew control, 201610746220.8; 106182218B, applicant: Guangxi Hengxian Zhenglin Wood Industry Co., Ltd., application date: 2016-08-29, abstract: the present invention adopts insect and mildew control The method for producing all-eucalyptus plywood with composite urea-formaldehyde resin comprises the following steps: board rotation → veneer drying → gluing → three cold pressings → standing and curing → three hot pressings → heat dissipation and curing → slab thickness sanding. The key of the production method of the present invention is to use melamine-modified urea-formaldehyde resin as the main material of the adhesive, and add oxidized starch as the adhesive compound;

[2] The method for producing eucalyptus birch wood composite floor by using high temperature-resistant composite urea-formaldehyde resin, 201610747076.X; 106272849B, applicant: Guangxi Hengxian Zhenglin Wood Industry Co., Ltd., application date: 2016-08-29, abstract: the present invention adopts resistant The method for producing eucalyptus birch composite floor with high temperature composite urea-formaldehyde resin, the steps are: plank rotation → veneer drying → gluing → three cold pressing → standing and curing → three hot pressing → heat dissipation and curing → slab thickness sanding → base Glue coating on the surface of the material → health grooving → lacquer drying and shaping. The key of the production method of the present invention is to use melamine-modified urea-formaldehyde resin as the main material of the adhesive.

[3] Method for producing all-eucalyptus plywood by using anti-corrosion composite urea-formaldehyde resin, 201610747071.7, 106313201B, applicant: Guangxi Hengxian Zhenglin Wood Industry Co., Ltd., application date: 2016-08-29, abstract: the present invention adopts anti-corrosion composite urea-formaldehyde resin to produce The method for the whole eucalyptus plywood comprises the following steps: board rotation → veneer drying → gluing → three cold pressing → standing for curing → three hot pressing → heat dissipation and curing → slab thickness sanding. The key of the production method of the present invention is to use melamine-modified urea-formaldehyde resin as the main material of the adhesive, and add oxidized starch as the adhesive compound;

[4] The method of producing eucalyptus birch wood composite floor by using insect-proof and mildew-proof compound urea-formaldehyde resin, 201610747086.3; 106335120B, applicant: Guangxi Hengxian Zhenglin Wood Industry Co., Ltd., application date: 2016-08-29, abstract: the use of insect-proof and mildew-proof composite floor The method for producing eucalyptus birch composite floor from urea-formaldehyde resin comprises the following steps: plank rotation → veneer drying → gluing → three cold pressings → standing and curing → three hot pressings → heat dissipation and curing → slab thickness sanding → substrate surface Gluing → health grooving → lacquer drying and shaping. The key of the production method of the present invention is to use melamine-modified urea-formaldehyde resin as the main material of the adhesive.

[5] The method for producing eucalyptus birch composite floor by using weather-resistant composite urea-formaldehyde resin, 201610746169.0, 106272848B, applicant: Guangxi Hengxian Zhenglin Wood Industry Co., Ltd., application date: 2016-08-29, abstract: the present invention adopts weather-resistant composite floor The method for producing eucalyptus birch composite floor from urea-formaldehyde resin comprises the following steps: plank rotation → veneer drying → gluing → three cold pressings → standing and curing → three hot pressings → heat dissipation and curing → slab thickness sanding → substrate surface Gluing → health grooving → lacquer drying and shaping. The key of the production method of the present invention is to use melamine-modified urea-formaldehyde resin as the main material of the adhesive.

[6] Method for producing cabinet board by using flame-retardant composite urea-formaldehyde resin, 201610752586.6, applicant: Guangxi Hengxian Zhenglin Wood Industry Co., Ltd., application date: 2016-08-29, abstract: the present invention relates to a kind of home building materials, in particular to adopting A method for producing a cabinet board with flame retardant composite urea-formaldehyde resin, the cabinet board has the following structure from top to bottom: decorative paper, fir veneer, particle board, backboard; aluminum alloy trimming around the cabinet board; fir veneer and particle board The flame-retardant composite urea-formaldehyde resin adhesive is coated between the particleboards and the flame-retardant composite urea-formaldehyde resin is coated between the particleboard and the backboard.

In the process of product production and application, although the applicant has come up with many technical solutions in the compound urea-formaldehyde resin adhesive, such as adding insect and mildew repellants, flame retardants, preservatives, high temperature resistant agents, etc., it also overcomes the existing problems. Many urea-formaldehyde resin adhesives have the disadvantage of releasing more formaldehyde, but there are still shortcomings in some aspects. For example, during the hot pressing process, sometimes the product is easily deformed when the pressure is not uniform, and sometimes the drying process is not uniform, and there is a phenomenon of cracking , Some sizing is uneven, and it cannot guarantee that the product formaldehyde exceeds the standard, and many technical indicators still need to be improved.

SUMMARY OF THE INVENTION

The technical scheme of the present invention is as follows:

The invention provides an anti-cracking low-aldehyde multi-layer eucalyptus board and a production method thereof. The production method of the multi-layer board comprises veneer sheet sorting, sheet gluing, cold pressing, hot pressing, standing for curing and scraping dust, The steps of sanding, repairing, trimming and veneering are characterized in that: before the first hot pressing and the last hot pressing, a layer of cured film is sprayed on the surrounding and upper and lower surfaces of the slab to protect and prevent the glue from passing through the hot pressing process. Fast drying, and maintain the internal stress of the multi-layer board, and can also make the urea-formaldehyde glue fully react, so that the formed multi-layer board is not easy to crack, and the volatile formaldehyde is reduced during the user's use process. , sanding and veneer, can be sawed and packaged to obtain crack-resistant low-aldehyde multi-layer eucalyptus board products.

The construction method of the cured film is to make the thermosetting resin, curing agent and auxiliary agent into powder, and after mixing, spray it around and above and below the surface of the slab. The cured film is firmly attached to the outer surface of the slab by the high temperature of the hot pressing process.

The above-mentioned cold pressing and hot pressing are 2 or 3 times, the cold pressing temperature is room temperature, the pressure is 0.8-1.0 MPa, and the hot pressing pressure is 1.5-2.0 MPa; the temperature of the first hot pressing is 120 ~125℃; the temperature of the second hot pressing is 115 ~ 120℃, and the temperature of the third hot pressing is 125 ~ 130℃; the temperature of the static curing is 80 ~ 90℃, and the time is 4 ~ 6h.

The adhesive used for coating the thin plate is urea-formaldehyde resin or phenolic resin.

The veneer board is a paint-free board or a board with flatness and smoothness, including poplar board, fir board and beech board, on the top or the upper and lower sides of the multi-layer eucalyptus board.

The above-mentioned cured film is composed of thermosetting resin, curing agent and auxiliary agent. The thermosetting resin adopts melamine formaldehyde resin, furfuryl alcohol resin or acrylic resin, the curing agent is biuret, and the auxiliary agent Or fillers include fiberglass, silicone, titanium dioxide, calcium carbonate. The parts by weight of the thermosetting resin are 40-60; the curing agent is 3-8; and the remainder of the auxiliary or filler.

In the above-mentioned thermosetting resins: the physical and chemical properties of various thermosetting resins are as follows:

Melamine-formaldehyde resin (English name melamine-formaldehyde resin), a polymer obtained by the reaction of melamine and formaldehyde. The cross-linking reaction occurs during processing and molding, and the product is an infusible thermosetting resin. The cured melamine formaldehyde resin is colorless and transparent, stable in boiling water, and can even be used at 150 ° C, and has self-extinguishing, arc resistance and good mechanical properties.

Furfuryl alcohol resin, English name furfuryl alcohol resin Definition Furan resin prepared from furfuryl alcohol as raw material. Adding a curing agent at room temperature can quickly cure into a thermoset material.

Acrylic resin, acrylic resin is a general term for acrylic acid, methacrylic acid and its derivative polymers. Acrylic resin coating is a thermoplastic or thermosetting resin coating, or acrylic radiation coating, which is made of (meth)acrylate and styrene as the main body, and acrylic resin obtained by copolymerization with other acrylates.

Thermosetting acrylic resin refers to a certain functional group in the structure, which forms a network structure by reacting with the functional groups in the amino resin, epoxy resin, polyurethane, etc. added during the paint making process. The relative molecular weight of thermosetting resin is generally low. Thermosetting acrylic coatings have excellent fullness, gloss, hardness, solvent resistance, weather resistance, no discoloration and no yellowing during high temperature baking.

Curing agent biuret, biuret is a long white crystal. Odorless. Hygroscopic. Those who crystallize in water contain 4 molecules of crystal water. It loses water at about 110 ° C, decomposes at 193 ° C, and becomes melamine when the temperature is higher. Soluble in ethanol, slightly soluble in ether.

As an aliphatic polyurethane curing agent, biuret has good weather resistance, good compatibility with solvents such as polyols or butyl acetate, and good high temperature solubility with polymers containing polyols after curing.

Silicone, silicone products are based on silicon-oxygen (Si-O) bond as the main chain structure, the bond energy of C-C bond is 82.6 kcal/mol, and the bond energy of Si-O bond in silicone is 82.6 kcal/mol. 121 kcal/mol, so the thermal stability of silicone products is high, and the chemical bonds of the molecules are not broken or decomposed under high temperature (or radiation exposure). Silicone is not only resistant to high temperatures, but also low temperatures, and can be used in a wide temperature range. Whether it is chemical properties or physical and mechanical properties, the change with temperature is very small. In the present invention, silane coupling agent, silicone oil (silicone grease, silicone emulsion, silicone surfactant), silicone resin, etc. can be selected; the unique structure of organic silicon combines the properties of inorganic materials and organic materials, and has low surface tension, viscosity and temperature It has the basic properties of small coefficient, high compressibility, high gas permeability, and has excellent characteristics such as high and low temperature resistance, electrical insulation, oxidation resistance stability, weather resistance, flame retardancy, hydrophobicity, corrosion resistance, non-toxic and tasteless, and physiological inertness.

The present invention has the following outstanding substantive features and remarkable progress:

1. With the improvement of people's living standards, the requirements for home decoration are also constantly improving. Due to its natural and beautiful texture and good texture, multi-layer boards have become the first choice for home furniture or floor decoration. The multi-layer composite board overcomes the shortcomings of solid wood board's wet expansion and dry shrinkage, has good dimensional stability, and at the same time retains the natural wood grain and comfortable foot feel of solid wood flooring, thus becoming an important variety in flooring. The solid wood composite board can be made by interlaced lamination of boards of different tree species, which overcomes the shortcoming of unidirectional homogeneity of solid wood boards, and has a small dry shrinkage and wet expansion rate. The solid wood composite board has both the stability of the reinforced board and the aesthetics of the solid wood board, and has the advantages of environmental protection, and the solid wood composite board not only has the advantages of the ordinary solid wood board, but also effectively adjusts the internal stress between the wood and improves the performance of the wood. Due to the large amount of deformation due to seasonal changes in dryness and humidity, it is favored by consumers.

2. In the prior art, if the multi-layer board is sometimes pressed evenly during the hot pressing process, the product is easily deformed, and sometimes the drying process is not uniform enough, there is a phenomenon of cracking, and some sizing is uneven, and the product formaldehyde cannot be guaranteed. Exceed the standard, use the present invention to spray a layer of cured film around and up and down the surface of the slab before the first hot pressing and the last hot pressing to protect the glue from drying too quickly during the hot pressing process, and maintain the internal stress of the multi-layer board. The urea-formaldehyde glue can be fully reacted, so that the formed multilayer board is not easy to crack, and the volatile formaldehyde is reduced during the user's use.

3. The multi-layer solid wood composite board of the present invention can be used in the production of bedrooms, living rooms, study rooms and offices, and can also be used as wooden floors. At present, the urea-formaldehyde and phenol-formaldehyde glues used in the solid wood composite board adhesives on the market release relatively large amounts of formaldehyde, while in the present invention, a layer of cured film is sprayed around and on the top and bottom of the surface of the slab before the first hot pressing and the last hot pressing. The increase, the formaldehyde emission concentration is greatly reduced.

Description of drawings

Fig. 1 is the process flow diagram of the production method of crack-resistant low-aldehyde multi-layer eucalyptus wood board of the present invention.

The production method of the multi-layer board embodying the present invention in the figure includes veneer sheet sorting, sheet gluing, three cold pressing, three hot pressing, secondary standing and curing and scraping, sanding, repairing, trimming and veneer. It is characterized in that: before the first cold pressing, repair trimming, the first hot pressing and the third hot pressing, a layer of cured film is sprayed around the surface of the slab and up and down to protect the glue from being hot-pressed. The drying process is too fast, and the internal stress of the multi-layer board is maintained, and the urea-formaldehyde glue can be fully reacted, so that the formed multi-layer board is not easy to crack, and the volatile formaldehyde is reduced during the user's use process. After standing, sanding and veneering, the board can be sawed and packaged to obtain crack-resistant low-aldehyde multi-layer eucalyptus board products.

Detailed ways

Example 1

A method for producing crack-resistant and low-aldehyde multi-layer eucalyptus boards, the production method of the multi-layer board comprises veneer sheet sorting, sheet gluing, three times of cold pressing, three times of hot pressing, two times of standing and curing and scraping ash and sand. The steps of lightening, repairing, trimming and veneering are characterized in that: before the first cold pressing, repairing trimming, the first hot pressing and the last hot pressing, a layer of cured film is sprayed around and up and down the surface of the slab , to protect the glue from drying too quickly during the hot pressing process, and to maintain the internal stress of the multi-layer board. It can also make the urea-formaldehyde glue fully react, so that the formed multi-layer board is not easy to crack, and the user process reduces volatile formaldehyde. , After the third hot pressing, the board can be left to stand, sanded and veneered, and then sawed and packaged to obtain crack-resistant low-aldehyde multi-layer eucalyptus board products.

The construction method of the cured film is to make the thermosetting resin, curing agent and auxiliary agent into powder, and after mixing, spray it around and above and below the surface of the slab. The cured film is firmly attached to the outer surface of the slab by the high temperature of the hot pressing process.

The above-mentioned cold pressing temperature is room temperature, the pressure is 0.8-1.0MPa, and the hot-pressing pressure is 1.5-2.0MPa; the temperature of the first hot-pressing is 120-125°C; the temperature of the second hot-pressing is 115-120 ℃, the temperature of the third hot-pressing is 125-130 ℃; the temperature of the static curing is 80-90 ℃, and the time is 4-6h.

The adhesive used for coating the thin plate is urea-formaldehyde resin.

The veneer board is a paint-free board or a board with flatness and smoothness, including poplar board, fir board and beech board, on the top or the upper and lower sides of the multi-layer eucalyptus board.

The above-mentioned cured film is composed of thermosetting resin, curing agent and auxiliary agent. The thermosetting resin adopts melamine formaldehyde resin, the curing agent is biuret, and the auxiliary agent or filler includes glass fiber. , Silicone, Titanium Dioxide, Calcium Carbonate. Among them, the parts by weight of thermosetting resin are 40-50; curing agent 5; auxiliary and filler glass fiber, silicone, titanium dioxide, calcium carbonate balance, wherein glass fiber 10-15; silicone 5, titanium dioxide 9, Calcium carbonate balance.

Example 2

A method for producing crack-resistant and low-aldehyde multi-layer eucalyptus boards, the production method of the multi-layer board comprises veneer sheet sorting, sheet gluing, primary cold pressing, secondary hot pressing, secondary standing and curing and scraping ash, The steps of sanding, repairing, trimming and veneering are characterized in that: before the first cold pressing, repairing trimming, the first hot pressing and the second hot pressing, a layer is sprayed around and above and below the surface of the slab The cured film protects and prevents the glue from drying too quickly during the hot pressing process, and maintains the internal stress of the multi-layer board. It can also make the urea-formaldehyde glue fully react, so that the formed multi-layer board is not easy to crack, and the user's use process reduces volatilization After the third hot pressing, the board can be left to stand, sanded and veneered, and then sawed and packaged to obtain crack-resistant low-formaldehyde multi-layer eucalyptus board products.

The construction method of the cured film is to make the thermosetting resin, curing agent and auxiliary agent into powder, and after mixing, spray it around and above and below the surface of the slab. The cured film is firmly attached to the outer surface of the slab by the high temperature of the hot pressing process.

The above-mentioned cold pressing temperature is room temperature, the pressure is 0.8 to 1.0 MPa, and the hot pressing pressure is 1.5 to 2.0 MPa; the temperature of the first hot pressing is 120 to 125 ° C; the temperature of the second hot pressing is 120 to 130 ℃; the temperature of the static curing is 80-90 ℃, and the time is 4-6h.

The adhesive used for coating the thin plate is modified phenolic resin.

The veneer board is a paint-free board or a board with flatness and smoothness, including poplar board, fir board and beech board, on the top or the upper and lower sides of the multi-layer eucalyptus board.

The above-mentioned cured film is composed of thermosetting resin, curing agent and auxiliary agent. The thermosetting resin adopts acrylic resin, the curing agent is biuret, and the auxiliary agent or filler includes glass fiber, Silicone, titanium dioxide, calcium carbonate. Wherein the parts by weight of acrylic resin are 50-60; curing agent 5; auxiliary and filler glass fiber, organosilicon, titanium dioxide, calcium carbonate balance, wherein glass fiber 10-15; organosilicon 8, titanium dioxide 5, calcium carbonate Add enough 100%.

The present invention adds the cured film product and does not add the cured layer product characteristic contrast:

Claims (5)

1. the production method of the anti-cracking low-formaldehyde multi-layer eucalyptus board comprises the steps of single board sheet separation, sheet gluing, cold pressing, hot pressing, standing, health preserving, dust scraping, sanding, repairing, trimming and panel pasting, and is characterized in that: spraying a layer of curing film on the periphery, the upper surface and the lower surface of the plate blank before the first hot pressing and the last hot pressing, protecting and preventing the glue from being dried too fast in the hot pressing process, keeping the stress in the multilayer board, fully reacting the urea-formaldehyde glue, and preventing the formed multilayer board from cracking easily, wherein the volatile formaldehyde is reduced in the using process;

the curing film is composed of thermosetting resin, curing agent and auxiliary agent, wherein the thermosetting resin is melamine formaldehyde resin, furfuryl alcohol resin or acrylic resin, the curing agent is biuret, and the auxiliary agent comprises glass fiber, organic silicon, titanium dioxide and calcium carbonate; wherein the weight portion of the thermosetting resin is 40-60; 3-8 parts of a curing agent; the balance of auxiliary agents or fillers.

2. The production method of the anti-cracking low-aldehyde multi-layer eucalyptus board as claimed in claim 1, wherein the production method comprises the following steps: the construction mode of the cured film is that the thermosetting resin, the curing agent and the auxiliary agent are made into powder, and the powder is sprayed on the periphery and the upper and lower surface of the plate blank after being mixed.

3. The production method of the anti-cracking low-aldehyde multi-layer eucalyptus board as claimed in claim 1, wherein the production method comprises the following steps: the cold pressing and the hot pressing are carried out for 2 times or 3 times, the cold pressing temperature is room temperature, the pressure is 0.8-1.0 MPa, and the hot pressing pressure is 1.5-2.0 MPa; the temperature of the first hot pressing is 120-125 ℃; the temperature of the second hot pressing is 115-120 ℃, and the temperature of the third hot pressing is 125-130 ℃; the standing and curing temperature is 80-90 ℃, and the time is 4-6 h.

4. The production method of the anti-cracking low-aldehyde multi-layer eucalyptus board as claimed in claim 1, wherein the production method comprises the following steps: the adhesive for gluing the thin plate is urea-formaldehyde resin or phenolic resin.

5. The method for producing anti-cracking low-formaldehyde multi-layer eucalyptus board according to claim 1, wherein the veneer is made by sticking paint-free boards or boards with flatness and smoothness on the upper surface or the upper and lower surfaces of the multi-layer eucalyptus board, including poplar boards, fir boards and beech boards.

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