Preparation method of antibacterial enhanced wood shavings veneer plywood

Abstract

This invention discloses a method for preparing antibacterial enhanced wood-plywood veneer plywood. The plywood layer comprises, from top to bottom, a PET veneer film, a wood-plywood layer, a wood-plywood layer, a wood-plywood layer, and a PET veneer film. The PET veneer film and the wood-plywood layer are bonded together with a foam adhesive; the wood-plywood layer and the plywood layer are bonded together with a foam adhesive. This method applies acetylene black and carbon fiber to the surface wood-plywood layer to form an absorbing grid, and incorporates tetrapod-shaped zinc oxide whiskers into the core board, thereby increasing both the overall strength and the overall absorbing performance of the board.

Description

[0001] Related patents

[0002] This application is a divisional application of the Chinese invention patent application with application number 2022107269032, application date June 23, 2022, and invention name “An antibacterial enhanced particleboard veneer plywood and its preparation method”. Technical Field

[0003] The invention belongs to the technical field of building materials, and particularly relates to a method for preparing an antibacterial enhanced wood shavings veneer plywood. Background Art

[0004] Artificial boards are the materials we interact with most daily. With the improvement of living standards, the demand for both antimicrobial and electromagnetic wave absorption performance is increasing. However, current artificial boards cannot achieve both. Antimicrobial agents are typically added to the coating to enhance the antimicrobial properties, while absorbent materials are added to enhance the electromagnetic absorption properties. Commonly used antimicrobial agents are inorganic, but the limited coating thickness can lead to wear of the inorganic antimicrobial agents. Furthermore, the limited coating thickness prevents uniform dispersion of the inorganic antimicrobial agents, making it difficult to achieve a sustained antimicrobial effect. Furthermore, adding absorbent materials to a coating of limited thickness can cause the absorbent materials to aggregate. This agglomeration not only reduces the absorption capacity but also weakens the bonding strength of the artificial board. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide an antibacterial enhanced particle veneer plywood that can absorb electromagnetic waves.

[0006] In order to achieve the above object, the present invention adopts the following technical means:

[0007] A first aspect of the present invention is to provide an antibacterial enhanced wood particle veneer plywood capable of absorbing electromagnetic waves, comprising, from top to bottom, a PET facing film, a wood particle layer, a plywood layer, a wood particle layer, and a PET facing film; the PET facing film and the wood particle layer are bonded to each other using a foam adhesive; the wood particle layer and the plywood layer are bonded to each other using a foam adhesive; the wood particle layer is made of modified fine wood particles, acetylene black, activated carbon fiber, luminous material, and a foam adhesive; the plywood layer is made of plywood and wood particles; and the plywood is formed by roller-coating a modified resin adhesive along the longitudinal grain of each veneer and then pressing the resultant material.

[0008] Preferably, the foaming adhesive is a foaming urea-formaldehyde resin adhesive.

[0009] Preferably, the modified resin adhesive is formed by mixing tetrapod-shaped zinc oxide whiskers, flour, nanomaterial dispersant and melamine-modified urea-formaldehyde resin in a mass ratio of tetrapod-shaped zinc oxide whiskers: flour: nanomaterial dispersant: melamine-modified urea-formaldehyde resin = 7:8:0.5:84.5.

[0010] Preferably, the nanomaterial dispersant is a carbon black dispersant, which helps to evenly disperse the nanomaterial.

[0011] Preferably, the luminous material is a rare earth doped alkaline earth metal aluminate long afterglow luminescent material, and the rare earth doped alkaline earth metal aluminate long afterglow luminescent material is SrAl2O4:Eu 2+ ,Dy 3+ 、CaAl2O4:Eu 2+ ,Nd 3+ or Sr4Al 14 O 25 :Eu 2 + ,Dy 3+ ;

[0012] A second aspect of the present invention is to provide a method for preparing an antibacterial enhanced particle veneer plywood capable of absorbing electromagnetic waves, comprising the following steps:

[0013] S1, after laying the veneers flat, use modified resin adhesive to roll-coat along the longitudinal grain of each veneer, let it age for 30 minutes after the roller coating, and then assemble it longitudinally and transversely, first put it into a cold press for pre-pressing for 2 hours, and then put it into a hot press for hot pressing to obtain the plywood layer;

[0014] S2, subjecting the wood shavings to high-pressure steam heat treatment and drying to air dryness, then stirring the wood shavings with water, zinc nitrate and nano zinc oxide for 30 minutes, and vacuum drying at 80°C, washing them twice with water and drying them to a moisture content of 3%; sieving to select modified fine wood shavings of 20-60 mesh for later use;

[0015] S3, mixing the modified fine wood shavings with acetylene black, activated carbon fiber, and luminous material to obtain a mixture, adding a foaming adhesive, stirring for 10 minutes, and then paving the mixture into a slab of uniform thickness, hot pressing, cooling, trimming, and sanding to obtain a particleboard;

[0016] S4, using the plywood layer obtained in step S1 as the core board, applying a foaming adhesive on the two outer surfaces of the plywood layer respectively, and paving the mixture obtained in step S3 respectively for pressing, and finally finishing the surface with a modified PET film to obtain an antibacterial enhanced particle veneer plywood that can absorb electromagnetic waves.

[0017] Preferably, in step S1, the hot pressing temperature is 120° C. and the hot pressing time is 11 minutes.

[0018] Preferably, in step S2, the temperature of the high-pressure steam heat treatment is 160° C., and the treatment time is 5 minutes.

[0019] Preferably, in step S2, the mass ratio of the wood chips, water, zinc nitrate and nano-zinc oxide is wood chips: water: zinc nitrate: nano-zinc oxide = 1:2:0.5:0.05.

[0020] Preferably, in step S3, the mass ratio of the modified wood shavings, acetylene black, activated carbon fiber and luminous material is modified wood shavings: acetylene black: activated carbon fiber: luminous material = 90:4:3:3; the mass of the foaming adhesive is 10% of the mass of the mixture.

[0021] Preferably, in step S4, the modified PET film is prepared by mixing polyester resin (PET), silver chloride-titanium dioxide and graphene oxide in a mass ratio of polyester resin:silver chloride-titanium dioxide:graphene oxide=1000:2:1.

[0022] Beneficial effects of the present invention

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention applies acetylene black and carbon fiber to the surface wood shavings to form an absorbing grid, and adds tetrapod-shaped zinc oxide whiskers to the core board. This not only increases the overall strength of the board but also enhances its overall absorbing properties. The application of luminescent material to the wood shavings can also promote electron migration over a period of time, stimulating zinc nitrate and nano-zinc oxide to form antibacterial ions and enhancing their antibacterial effects. The addition of silver chloride-titanium dioxide and graphene oxide to the modified PET film dissolves the metal ions when exposed to water, achieving a long-lasting antibacterial effect. Furthermore, the antibacterial particles produced by the wood shavings can adhere to the film, enhancing its surface antibacterial properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It shows a structural diagram of embodiment 1 of the present invention;

[0026] Figure 2 A photograph of the antibacterial enhanced particle veneer plywood prepared in Example 1 of the present invention is shown;

[0027] Figure 3 A photograph of the antibacterial enhanced particle veneer plywood prepared in Example 1 of the present invention is shown;

[0028] In the figure, 1. Modified PET finishing film; 2. Wood particle layer; 3. Plywood layer. DETAILED DESCRIPTION

[0029] Unless otherwise indicated, implied from the context, or customary in the art, all parts and percentages in this application are based on weight, and the test and characterization methods used are current as of the filing date of this application. Where applicable, the contents of any patents, patent applications, or publications referred to in this application are incorporated herein by reference in their entirety, and their equivalent patent families are also incorporated by reference, especially with respect to definitions of synthetic techniques, product and processing designs, polymers, comonomers, initiators, or catalysts disclosed in these documents in the art. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in this application, the definition of the term provided in this application shall prevail.

[0030] The numerical ranges in this application are approximate, so unless otherwise stated, they may include values outside the range. Numerical ranges include all values from the lower limit to the upper limit in increments of 1 unit, provided that there is an interval of at least 2 units between any lower value and any higher value. For example, if a component, physical or other property (such as molecular weight, melt index, etc.) is recorded as 100 to 1000, it means that all individual values, such as 100, 101, 102, etc., and all subranges, such as 100 to 166, 155 to 170, 198 to 200, etc., are clearly listed. For ranges containing values less than 1 or containing fractions greater than 1 (such as 1.1, 1.5, etc.), 1 unit is appropriately regarded as 0.0001, 0.001, 0.01 or 0.1. For ranges containing single digits less than 10 (such as 1 to 5), 1 unit is usually regarded as 0.1. These are only specific examples of what is intended, and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application.

[0031] When used with respect to chemical compounds, unless expressly stated otherwise, the singular includes all isomeric forms, and vice versa (e.g., "hexane" includes all isomers of hexane, individually and collectively). In addition, nouns using "a," "an," or "the" include the plural unless expressly stated otherwise.

[0032] The terms "comprising", "including", "having" and their derivatives do not exclude the presence of any other components, steps or processes, and are irrelevant to whether these other components, steps or processes are disclosed in this application. To eliminate any doubt, all compositions using the terms "comprising", "including", or "having" in this application may include any additional additives, excipients or compounds unless expressly stated otherwise. In contrast, the term "essentially consisting of" excludes any other components, steps or processes from the scope of any subsequent description of the term, except those necessary for operational performance. The term "consisting of" does not include any components, steps or processes that are not specifically described or listed. Unless expressly stated otherwise, the term "or" refers to the listed members alone or in any combination.

[0033] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the embodiments.

[0034] Example

[0035] The following examples are provided to illustrate preferred embodiments of the present invention. Those skilled in the art will appreciate that the techniques disclosed in the following examples represent techniques discovered by the inventors that can be used to practice the present invention and, therefore, can be considered preferred embodiments of the present invention. However, those skilled in the art will appreciate from this disclosure that many modifications may be made to the specific embodiments disclosed herein while still achieving the same or similar results without departing from the spirit or scope of the present invention.

[0036] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and the disclosure and materials they cite are hereby incorporated by reference.

[0037] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many technical equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the claims.

[0038] Example 1

[0039] This embodiment provides an antibacterial enhanced particleboard veneer plywood that can absorb electromagnetic waves, combined with Figure 1 As shown, from the outside to the inside are a PET facing film, a wood particle layer as a surface layer, and a plywood layer as a core board; the PET facing film and the wood particle layer are bonded together by a foamed urea-formaldehyde resin adhesive; and the wood particle layer and the plywood layer are bonded together by a foamed urea-formaldehyde resin adhesive.

[0040] This embodiment also provides a method for preparing the above-mentioned antibacterial enhanced wood shavings veneer plywood, which comprises the following steps:

[0041] S1, after laying the veneers flat, use a modified resin adhesive to roll-coat them along the longitudinal grain of each veneer, let them stand for 30 minutes after the roll-coating, and then assemble them vertically and horizontally, first place them in a cold press for pre-pressing for 2 hours, and then place them in a hot press for hot pressing at 120° C. for 11 minutes to obtain a plywood with 7 layers; wherein the modified resin adhesive is mixed with tetrapod-shaped zinc oxide whiskers, flour, nanomaterial dispersant and melamine-modified urea-formaldehyde resin in a mass ratio of tetrapod-shaped zinc oxide whiskers: flour: nanomaterial dispersant: melamine-modified urea-formaldehyde resin = 7:8:0.5:84.5;

[0042] S2, subjecting the wood shavings to a high-pressure steam heat treatment at a temperature of 160° C. for 5 minutes, and then drying them to air dryness, and then mixing the wood shavings with water, zinc nitrate, and nano-zinc oxide in a mass ratio of wood shavings: water: zinc nitrate: nano-zinc oxide = 1:2:0.5:0.05 for 30 minutes, and vacuum drying at 80° C., washing them twice with water, and drying them to a moisture content of 3%; sieving to select modified fine wood shavings of 20-60 mesh for later use;

[0043] S3, modified fine wood shavings and acetylene black, activated carbon fiber, SrAl2O4:Eu 2+ ,Dy 3+ Modified fine wood shavings: acetylene black: activated carbon fiber: SrAl2O4:Eu 2+ ,Dy 3+ =90:4:3:3 by mass ratio, and add 10% of the mass of the mixture to a foamed urea-formaldehyde resin adhesive, and stir for 10 minutes to obtain a mixture;

[0044] S4, using the plywood layer obtained in step S1 as the core board, applying foamed urea-formaldehyde resin adhesive to the two outer surfaces of the plywood layer, and paving the mixture obtained in step S3 respectively for pressing, and finally finishing the surface with a modified PET film to obtain an antibacterial enhanced particle veneer plywood that can absorb electromagnetic waves. Figure 2 and Figure 3 The modified PET film is prepared by mixing PET, silver chloride-titanium dioxide and graphene oxide in a mass ratio of PET: silver chloride-titanium dioxide: graphene oxide = 1000:2:1.

[0045] Comparative Example 1

[0046] Comparative Example 1 is compared with Example 1, except that fibrous zinc oxide whiskers are used instead of tetrapod-shaped zinc oxide whiskers in Comparative Example 1.

[0047] Comparative Example 2

[0048] Comparative Example 2 is compared with Example 1, except that in step S3 of Comparative Example 2, modified fine wood particles are mixed with acetylene black, activated carbon fiber, SrAl2O4:Eu 2+ ,Dy 3+ Modified fine wood shavings: acetylene black: activated carbon fiber: SrAl2O4:Eu 2+ ,Dy 3+ =90:4:3:0.5 mass ratio for mixing.

[0049] Comparative Example 3

[0050] Compared with Example 1, Comparative Example 3 is different in that nano-activated carbon is used instead of acetylene black.

[0051] Comparative Example 4

[0052] Comparative Example 4 is compared with Example 1, except that corn flour is used instead of flour in Comparative Example 4.

[0053] Comparative Example 5

[0054] Compared with Example 1, Comparative Example 5 is different in that the fluorescent material rhodamine is used instead of the luminous material in Comparative Example 5.

[0055] Comparative Example 6

[0056] Compared with Example 1, Comparative Example 6 is different in that the modified PET film is replaced by a PET film.

[0057] The performance of the antibacterial enhanced wood shavings veneer plywood prepared in Example 1 and Comparative Examples 1-6 was tested.

[0058] The radar absorbing performance test was carried out according to the GJB2038A-2011 radar absorbing material reflectivity test method. The test results are shown in Table 1.

[0059] Mechanical properties tests were conducted according to GB / T 17657-2013 “Test methods for physical and chemical properties of wood-based panels and veneered wood-based panels”. The test results are shown in Table 1.

[0060] The oscillation method of GB / T 20944.3-2008 was used, and Escherichia coli, Staphylococcus aureus, and Candida albicans were selected as the test species. Five samples were tested in parallel for each example and comparative example, and the average value was taken. The results are shown in Table 1.

[0061] Evaluation of antibacterial effect: If the inhibition rate of Escherichia coli and Staphylococcus aureus is ≥70%, and the inhibition rate of Candida albicans is ≥60%, it has antibacterial effect;

[0062] Table 1, performance test results

[0063]

[0064] The minimum reflection frequency of Example 1 is -23.2 dB, the minimum reflection frequency of Comparative Example 1 is -15.0 dB, and the minimum reflection frequency of Comparative Example 3 is -14.7 dB. From the above data, it can be seen that when acetylene black or tetrapod-shaped zinc oxide whiskers are changed, the absorption performance of the prepared antibacterial enhanced particleboard veneer plywood decreases. This shows that the present invention can enhance the overall absorption performance of the board by applying acetylene black and carbon fiber to the surface particle layer to form an absorbing grid and adding tetrapod-shaped zinc oxide whiskers to the core board.

[0065] The above data show that the minimum reflection frequencies of Example 1 and Comparative Example 4 are similar. However, the bonding strength of Comparative Example 4 is only 0.89 MPa, which is much lower than 1.85 MPa. This indicates that the flour, tetrapod-shaped zinc oxide whiskers, and melamine-modified urea-formaldehyde resin form a three-dimensional cross-linked system that enhances the mechanical properties of the plywood.

[0066] It can be seen from the data of Example 1 and Comparative Example 2 that the antibacterial performance of the plywood prepared using the ratio of Example 1 of the present invention is significantly better than that of the plywood prepared in Comparative Example 2.

[0067] All documents mentioned in this application are incorporated herein by reference, just as if each document were incorporated herein by reference individually. It should also be understood that after reading the above teachings of the present invention, those skilled in the art may make various changes or modifications to the present invention, and that such equivalents also fall within the scope of the claims appended hereto.

Claims

1. A method for preparing an antibacterial enhanced wood shavings veneer plywood, characterized in that: From top to bottom, they are PET facing film, wood particle layer, plywood layer, wood particle layer and PET facing film. The preparation method comprises the following steps: S1, after laying the veneer flat, use a modified resin adhesive to roll-coat it along the longitudinal grain of each veneer, let it age for 30 minutes after the roller coating, and then assemble it vertically and horizontally, first place it in a cold press for pre-pressing for 2 hours, and then place it in a hot press for hot pressing to obtain a plywood layer; wherein the hot pressing temperature is 120° C. and the hot pressing time is 11 minutes. The modified resin adhesive is composed of tetrapod-shaped zinc oxide whiskers, flour, nanomaterial dispersant and melamine-modified urea-formaldehyde resin in a mass ratio of tetrapod-shaped zinc oxide whiskers: flour: nanomaterial dispersant: melamine-modified urea-formaldehyde resin = 7:8:0.5:84.5; S2, subjecting the wood shavings to a high-pressure steam heat treatment at a temperature of 160° C. for 5 minutes; drying the wood shavings to air dryness, and then mixing the wood shavings with water, zinc nitrate, and nano-zinc oxide in a mass ratio of wood shavings: water: zinc nitrate: nano-zinc oxide = 1:2:0.5:0.05 for 30 minutes, vacuum drying at 80° C., washing the wood shavings twice with water, and drying the wood shavings to a moisture content of 3%; sieving the wood shavings to obtain modified fine wood shavings of 20-60 mesh for later use; S3, mixing the modified wood shavings with acetylene black, activated carbon fiber, and luminous material in a mass ratio of modified wood shavings: acetylene black: activated carbon fiber: luminous material = 90:4:3:3, adding a foaming adhesive, and stirring for 10 minutes to obtain a mixture; S4, using the plywood layer obtained in step S1 as the core board, applying a foaming adhesive to the two outer surfaces of the plywood layer, and paving the mixture obtained in step S3 on the two outer surfaces for pressing, and finally finishing the surface with a modified PET film to obtain the antibacterial enhanced particle veneer plywood. The modified PET film is prepared by mixing polyester resin, silver chloride-titanium dioxide and graphene oxide in a mass ratio of polyester resin:silver chloride-titanium dioxide:graphene oxide=1000:2:

1.

2. The preparation method according to claim 1, characterized in that The luminous material is a rare earth doped alkaline earth metal aluminate long afterglow luminescent material.

3. The preparation method according to claim 1 or 2, characterized in that The luminous material is SrAl2O4:Eu 2+ ,Dy 3 + .

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