阅读说明：本技术 一种络合刨花、络合刨花板及其制造方法 (Complexing wood shavings, complexing shaving board and manufacturing method thereof ) 是由 余养伦 于文吉 吕斌 张耀明 于 2019-09-20 设计创作，主要内容包括：本发明涉及一种络合刨花、络合刨花板及其制造方法,属于人造板加工技术领域。所述络合刨花板由络合刨花和胶黏剂组成,在所述络合刨花引入了植物多酚金属盐络合物,将金属离子通过植物多酚固定在刨花表面、细胞壁、细胞腔和/或细胞间隙中,不仅有效地改变了刨花板的色泽,而且增加了刨花板的防水、反腐、防霉等性能。(The invention relates to a complex wood shavings, a complex shaving board and a manufacturing method thereof, belonging to the technical field of artificial board processing. The complex shaving board is composed of complex shavings and an adhesive, wherein a plant polyphenol metal salt complex is introduced into the complex shavings, and metal ions are fixed on the surfaces, cell walls, cell cavities and/or cell gaps of the shavings through plant polyphenol, so that the color of the shaving board is effectively changed, and the performances of the shaving board, such as water resistance, corrosion resistance, mildew resistance and the like, are improved.)

1. A complex wood shaving comprising wood shavings, a plant polyphenol and a metal salt; the plant polyphenol and metal salt are present in the strands in a complex form and distributed on the surface, cell walls, cell cavities and/or interstitial spaces of the strands.

2. The complex wood shavings of claim 1 wherein the plant polyphenol is a polygallate and/or a polyflavanoid plant polyphenol; the gallate polyphenol comprises at least one polyalcohol and a plurality of phenolic carboxylic acids, wherein the polyalcohol is connected with the phenolic carboxylic acids through ester bonds; the molecular weight of the polyflavan polyphenol is 500-3000, the polymer is 2-10, the units are connected by C-C bonds, and the molecular skeleton is C₆·C₃·C₆The structure is that two phenol rings (ring A and ring B) are connected by a three-carbon chain (C-2, C-3 and C-4), wherein one carbon atom is connected with an oxygen atom at the position of ring A8 a to form a pyran ring (ring C).

3. The complexed wood shavings of claim 1 wherein the plant polyphenol is one or more of tannin extract, tannin, tannic acid, terminal carnivorous acid, pyrogenous terminal carnivorous acid;

the metal salt is one or a mixture of iron salt, copper salt and borate metal salt.

4. A method of making a complex wood chip comprising:

step 1: preparing a proper amount of wood shavings;

step 2: introducing plant polyphenol into wood shavings to obtain polyphenol wood shavings;

and step 3: introducing metal salt into the polyphenol wood shavings to obtain polyphenol metal salt wood shavings;

and 4, step 4: and drying the wood shavings to obtain the complex wood shavings.

5. The method of making a complexed shaving according to claim 4, wherein step 2 is:

21) dissolving plant polyphenol in water, and stirring uniformly to form a plant polyphenol water solution;

22) soaking the wood shavings in plant polyphenol water solution;

23) drying the wood shavings impregnated with the aqueous solution of plant polyphenols.

6. The method for preparing the complex wood shavings according to claim 5 wherein the aqueous solution of the plant polyphenol has a concentration of 1g/L to 25.0g/L, an average molecular weight of 170 to 50000, and is a 1 to 40 polymer; soaking the wood shavings in plant polyphenol water solution for 10min-48h at 0-80 deg.C under normal pressure or under pressure;

the plant polyphenol is one or more of tannin extract, tannin, tannic acid, terminal food acid, and charred terminal food acid.

7. The method of making a complexed shaving according to claim 4, wherein step 3 is:

31) dissolving metal salt in water, and stirring uniformly to form a metal salt water solution;

32) immersing the polyphenol wood shavings into a metal salt aqueous solution.

8. The method of making a complex shaving according to claim 7, wherein the concentration of the aqueous metal salt solution is 0.3g/L to 30.0 g/L; soaking the wood shavings in a metal salt aqueous solution for 10min-24h at the temperature of 0-80 ℃, wherein the soaking method is normal pressure or pressurization;

the metal salt is one or a mixture of iron salt, copper salt and borate metal salt.

9. A composite particle board comprising the composition of any of claims 1-3The complexing wood shavings are formed by random or directional overlapping and stacking, a phenolic adhesive or a urea-formaldehyde adhesive is arranged at the overlapping position, and the density of the shaving board is 0.65-1.10g/cm³。

10. A method of making a composite particle board from the composite strands of any of claims 1-3, comprising:

101) drying

Drying the complex wood shavings by adopting an airflow method until the moisture content is 2-5%, wherein the temperature of the airflow at the inlet is 370-400 ℃, the temperature of the drying medium is 160-190 ℃, and the oxygen content of the drying medium is 13-18%;

102) sizing

Uniformly spraying phenolic resin or urea-formaldehyde resin on the surface of the complex wood shavings by adopting a spray sizing method, wherein the sizing amount of the phenolic resin is 5-10%; if the urea resin is used, the glue application amount is 8-12%;

103) paving and forming

Spreading the dried wood shavings by air flow spreading to obtain a surface density of 0.15-0.45g/cm²The slab of (1);

104) hot pressing

Feeding the plate blank into a multi-layer hot press or a continuous hot press, and hot-pressing to obtain the plate blank with the density of 0.65-1.10g/cm³The particle board.

Technical Field

The invention relates to the technical field of artificial board processing, in particular to a complex wood shavings, a complex shaving board and a manufacturing method thereof.

Background

Particle board, also called particle board, is a wood composite material made by wood or other wood materials after being made into wood shavings, applying adhesive and then gluing under the action of heat and pressure. Because of the characteristics of good physical and mechanical properties, easy processing and the like, the material has wide application in the fields of plate furniture, building structural materials and decorative materials. With the continuous development of shaving boards in the field of home decoration and the continuous pursuit of people for beautiful life. During decoration, the pursuit of wooden products is greatly changed from practicability to individuation, functionalization and the like, the existing shaving board processing technology is difficult to realize the unification of the individuation and the functionalization, for example, the shaving board needs to be dyed when the color of the shaving board is increased; the water resistance of the shaving board is improved by mainly adding water-proofing agents such as paraffin and the like; increasing preservative performance requires the addition of preservatives; a mildew preventive is required for increasing the mildew resistance; and it is difficult to superimpose the above functions simultaneously in the same product or in the same process.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a complex wood shaving, a complex shaving board and a manufacturing method thereof. The complex shaving board prepared by the method not only effectively changes the color of the shaving board, but also has the advantages of improving the performances of water resistance, corrosion resistance, mildew resistance and the like of the shaving board, and can effectively prevent the shaving board from cracking.

In order to solve the technical problems, the invention provides the following technical scheme:

in one aspect, the invention provides a complex wood shaving, prepared from wood shavings, a plant polyphenol and a metal salt; the plant polyphenol and metal salt are present in the strands in a complex form and distributed on the strand surface, cell walls, cell cavities and/or intercellular spaces.

Further, the plant polyphenol is polygallate and/or polyflavane plantA polyphenol; the gallate polyphenol comprises at least one polyalcohol and a plurality of phenolic carboxylic acids, wherein the polyalcohol is connected with the phenolic carboxylic acids through ester bonds; the molecular weight of the polyflavan polyphenol is 500-3000, the polymer is 2-10, the units are connected by C-C bonds, and the molecular skeleton is C₆·C₃·C₆The structure is that two phenol rings (ring A and ring B) are connected by a three-carbon chain (C-2, C-3 and C-4), wherein one carbon atom is connected with an oxygen atom at the position of ring A8 a to form a pyran ring (ring C).

In another aspect, the invention also provides a preparation method of the complex wood shavings, which comprises the steps of

Step 1: preparing a proper amount of wood shavings;

step 2: introducing plant polyphenol into wood shavings to obtain polyphenol wood shavings;

and step 3: introducing metal salt into the polyphenol wood shavings to obtain polyphenol metal salt wood shavings;

and 4, step 4: and drying the wood shavings to obtain the complex wood shavings.

Further, the step 2 is as follows:

21) dissolving plant polyphenol in water, and stirring uniformly to form a plant polyphenol water solution;

22) soaking the wood shavings in plant polyphenol water solution;

23) drying the wood shavings impregnated with the aqueous solution of plant polyphenols.

Preferably, the concentration of the plant polyphenol water solution is 1-25.0 g/L, the average molecular weight is 170-50000, and the plant polyphenol water solution is 1-40 polymers; soaking the wood shavings in plant polyphenol water solution for 10min-48h at 0-80 deg.C under normal pressure or under pressure;

the plant polyphenol is one or more of tannin extract, tannin, tannic acid, terminal food acid, and charred terminal food acid.

Soaking the wood shavings in a polyphenol solution, wherein the wood shavings gradually swell by the action of water, and the plant polyphenol is gradually introduced to the surfaces, cell walls, cell cavities and/or cell gaps of the wood shavings until a preset impregnation amount is reached; and taking out the wood shavings, placing the wood shavings in a drying kiln or air to gradually evaporate water in the wood shavings, increasing the concentration of the plant polyphenol in the cells, beginning to precipitate when the concentration of the plant polyphenol reaches an isoelectric point, and solidifying the plant polyphenol in the wood shavings under the action of hydrogen bonds and/or hydrophobic bonds to form the polyphenol wood shavings.

Further, the step 3 is:

31) dissolving metal salt in water, and stirring uniformly to form a metal salt water solution;

32) immersing the polyphenol wood shavings into a metal salt aqueous solution.

Preferably, the concentration of the metal salt aqueous solution is 0.3 g/L-30.0 g/L; soaking the wood shavings in a metal salt aqueous solution for 10min-24h at the temperature of 0-80 ℃, wherein the soaking method is normal pressure or pressurization;

the metal salt is one or a mixture of iron salt, copper salt and borate metal salt.

Soaking polyphenol wood shavings in metal salt, gradually swelling wood shavings cell walls under the action of water, and gradually introducing the metal salt to the surfaces, cell walls, cell cavities and/or cell gaps of the wood shavings until a preset impregnation amount is reached; the plant polyphenol and the metal salt are complexed in the wood shavings, the wood shavings and the plant polyphenol metal salt complex are combined through hydrogen bonds, defibering bonds and covalent bonds, and the polyphenol metal salt complex is chelated by five-membered rings formed by ortho-diphenol hydroxyl of the plant polyphenol and ions.

On the other hand, the invention also provides a complex shaving board which comprises 1-95% of the complex shaving boards.

Plant polyphenol metal salt is arranged on the surfaces of the wood shavings and/or cell cavities, cell walls and/or cell gaps in the wood shavings, and the wood shavings are directionally arranged along the grains and/or randomly arranged and are glued into a whole through an adhesive.

In another aspect, the present invention also provides a method for preparing a complex particle board, comprising the above complex particle board, comprising:

101) drying

Drying the complex wood shavings by adopting an airflow method until the moisture content is 2-5%, wherein the temperature of the airflow at the inlet is 370-400 ℃, the temperature of the drying medium is 160-190 ℃, and the oxygen content of the drying medium is 13-18%;

102) sizing

Uniformly spraying phenolic resin or urea-formaldehyde resin on the surface of the complex wood shavings by adopting a spray sizing method, wherein the sizing amount of the phenolic resin is 5-10%; if the urea-formaldehyde resin is adopted, the glue application amount is 8-12%

103) Paving and forming

Spreading the dried wood shavings by air flow spreading to obtain a surface density of 0.15-0.45g/cm²The slab of (1);

104) hot pressing

Feeding the plate blank into a multi-layer hot press or a continuous hot press, and hot-pressing to obtain the plate blank with the density of 0.65-1.10g/cm³The particle board.

The existing research considers that the particleboard cracks for a plurality of reasons, wherein the main factor is that polysaccharides (cellulose, hemicellulose and the like) in the particleboards absorb or release water in the processes of moisture absorption and desorption to cause the particleboards to expand or contract, thereby causing the size instability of the particleboards.

Compared with the prior art, the invention has the following beneficial effects:

the method comprises the steps of firstly, introducing plant polyphenol into wood shavings, wherein the phenolic hydroxyl group of the plant polyphenol is combined with the alcoholic hydroxyl groups in cellulose and hemicellulose in the wood shavings through hydrogen bonds, untwining bonds and covalent bonds, so that hydrophilic groups in the wood shavings are reduced, and the phenolic hydroxyl group and benzene ring of the plant polyphenol enable the wood shavings to have hydrophilicity and hydrophobicity;

meanwhile, the introduction of the metal salt can effectively increase the properties of the shaving board such as corrosion resistance and mildew resistance, and the color of the shaving board is changed to a certain extent, so that the shaving board has the color of the metal salt, and the metal salt ions and the plant polyphenol are complexed in wood, so that the metal salt ion complex wood is stable and is not easy to fade.

According to the invention, plant polyphenol and metal salt are introduced into the cell wall of the wood shavings, the plant polyphenol and the metal salt are complexed in the wood shavings, the wood shavings and the plant polyphenol metal salt complex are mainly combined through hydrogen bonds, defibering bonds and covalent bonds, and the polyphenol metal salt complex is chelated by five-membered rings formed by ortho-position diphenol hydroxyl of the plant polyphenol and ions. The molecular chains of adjacent cellulose/hemicellulose are crosslinked into a net structure, just as a plurality of supports are supported on the molecular chain branches of the cellulose/hemicellulose, so that the molecular chains of the cellulose/hemicellulose are reduced or even do not expand or contract when absorbing or desorbing moisture; on the basis, a large number of multiple sacrificial bond networks consisting of hydrogen bonds (the plant polyphenol phenolic hydroxyl groups are combined with the hydroxyl groups in the wood shavings to form multi-point hydrogen bonds) and coordination bonds (the ortho hydroxyl groups on the plant polyphenol phenolic rings are complexed with metal salts to form coordination bonds) are formed in the cellulose skeleton. Because the sacrificial bond energy is less than the covalent bonds (a network of covalent bonds is formed between the cellulose, hemicellulose, lignin, and phenolic resin), when the strands are subjected to internal or external stresses, the sacrificial bonds break in preference to the covalent bonds. The dynamic action of the continuous breakage and reconstruction of the sacrificial bonds dissipates a large amount of energy in a wood shaving system, eliminates or weakens internal stress, and protects the integrity of a cellulose skeleton covalent bond network. This provides a new approach to solving the problem of wood chip cracking.

Firstly, plant polyphenol is introduced into wood shavings to ensure that the wood shavings are swollen; then introducing metal salt into the wood shavings, combining the plant polyphenol with cellulose and hemicellulose in the wood shavings to form a multi-point hydrogen bond, complexing the plant polyphenol with the metal salt, and combining the cellulose-plant polyphenol-metal salt into a whole just like forming a plurality of support supports in cellulose skeleton molecules; then, accompanied by evaporation and oxidation reaction of water, the "cellulose-plant polyphenol-metal salt" is further cross-linked and oxidized, finally forming a complex wood wool. The dynamic multi-sacrifice bond network structure of the invention 'cellulose-plant polyphenol-metal salt' supports cellulose and/or hemicellulose, so that the dynamic effect of the repeated breakage and reconstruction of sacrifice bonds is reduced or even avoided when the cellulose and/or hemicellulose absorbs moisture or desorbs moisture, a large amount of energy in a wood recombination material system is dissipated, the internal stress is eliminated or weakened, the integrity of a cellulose skeleton covalent bond network is protected, and the problem of easy cracking of wood shavings at the molecular level is solved.

Drawings

FIG. 1 shows the condition of wood shavings before and after treatment in example 1 of the present invention;

FIG. 2 is a graph showing the contact angles of water on the surface of radiata pine wood shavings before and after treatment in example 1 of the present invention;

FIG. 3 shows the condition of wood shavings before and after treatment in example 2 of the present invention;

FIG. 4 shows the contact angles of water on the surface of eucalyptus strands before and after the treatment in example 2 of the present invention;

FIG. 5 is an oriented strand board made according to example 4 of the present invention;

figure 6 shows a particle board made according to example 5 of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following detailed description is given with reference to specific embodiments.

In the present invention, the materials and reagents used are not specifically described, and are commercially available.