Alkylamine dry-wet alternating fumigation wood floor and preparation process thereof

Abstract

The application discloses alkyl amine dry-wet alternating fumigation wood floor and a preparation process thereof, and belongs to the technical field of veneer processing and application. In view of the problems of poor stability of the veneer product, difficulty in taking into account the coloring effect and the substrate adhesion, and uneven penetration of fumigation gas in the traditional ammonia fumigation process for processing wood floor, the application takes oak, hickory, birch and eucalyptus veneer as the processing object, and sequentially carries out alkyl fumigation dry fumigation, ammonia fumigation dry fumigation, balance treatment, alkyl fumigation wet fumigation and ammonia fumigation wet fumigation, and applies activators such as tannin and hydrogen peroxide to the color difference area of the veneer. The application can dredge wood fibers through alkyl fumigation, catalyze ammonia gas and internal tannin and polyphenol of the wood to fully complex and develop color in the dry-wet alternating environment, release internal stress of the veneer in the balance process, and stabilize the complex. Compared with the traditional ammonia fumigation process, the wood floor prepared by the application has uniform color, is not easy to fade in long-term storage, and is not easy to warp and deform.

Description

Technical Field

[0001] This invention belongs to the field of raw board processing and application technology, specifically relating to an alkanesamine alternating wet and dry fumigation process for wood flooring and its preparation process. Background Technology

[0002] Currently, most solid wood flooring and engineered wood flooring use economical raw boards such as oak, hickory, birch, and eucalyptus as raw materials. However, raw boards on the market generally have natural color differences, and there are very few defect-free trees. Most raw boards have natural board surface characteristics such as knots, holes, decay, and large color differences. It is difficult to completely unify the texture and color of the board surface by simply relying on conventional sanding and surface coating.

[0003] Currently, the mainstream process in the industry is single ammonia fumigation modification technology for wood flooring. This technology involves placing the raw wood flooring in a closed space and using pure ammonia or high-concentration ammonia water to naturally evaporate and fumigate the surface. While ammonia fumigation is a conventional modification method and simple to operate, it has unavoidable technical drawbacks in actual production and product application. Traditional ammonia fumigation relies solely on a single concentration of gas on the surface of the raw board for an instantaneous reaction. The reaction rate is uncontrollable, and gas penetration is uneven. This results in significant differences in color intensity across the board's grain and different areas, making it impossible to achieve a uniform color across the entire board. Furthermore, ammonia fumigation is a surface chemical reaction; the internal wood structure and tannin components of the raw board are not stabilized. The internal stress and color development system of the raw board are unstable, leading to poor color stability in the finished wood flooring. Product consistency and durability cannot be guaranteed, and wood flooring modified with single ammonia fumigation typically has a dull surface color and insufficient translucency.

[0004] Patent CN119614022A discloses a method for preparing a colorant based on waste ammonia water generated during the smoking process of wood panels, as well as the colorant itself. This patent uses starch adsorption for coloring and acrylic acid-acrylamide for thickening, solving the problem of dull color development in traditional systems. However, this method still suffers from issues such as the colorant floating on the surface and system instability.

[0005] In summary, to address the problem that traditional ammonia fumigation processes for wood flooring often result in a difficulty in achieving both effective coloring and good adhesion to the substrate, this invention proposes a method for fumigating wood flooring using alternating wet and dry ammonia fumigation and its preparation process. Summary of the Invention

[0006] The purpose of this invention is to provide a process for fumigating wood flooring with alternating wet and dry alkylammonia, and to solve the problems mentioned in the background art.

[0007] The above-mentioned objective of this invention is achieved through the following technical solution: a method for preparing wood flooring that undergoes alternating wet and dry fumigation with alkylamine, comprising the following steps: S1: Stack the bare wood flooring boards using an exposed board stacking method, with a stacking height of 2m; S2: The stacked raw boards are subjected to alkane fumigation for 8-10 hours, ammonia fumigation for 8-10 hours, balancing treatment for 12 hours, alkane fumigation for 8-10 hours, ammonia fumigation for 8-10 hours, and balancing treatment for 12-14 hours in sequence. S3: Apply an activator to areas with color differences on the surface of the raw board; S4: After coating, the raw board is subjected to ammonia fumigation for 8-10 hours and equilibration treatment for 12-14 hours.

[0008] Furthermore, the process conditions for alkane fumigation and ammonia fumigation are: relative humidity 40%-50% and temperature 20℃-30℃.

[0009] The core of achieving a stable smoked color in raw wood veneer lies in the complexation reaction between ammonia and the lignin and tannins within the veneer. During the dry smoking stage, a humidity level of 40%-50% allows alkane gases to open the pores of the veneer, breaking down the closed fiber structure and providing a channel for the subsequent deep penetration of ammonia. Ammonia can also quickly diffuse into the depths of the veneer, initially combining with the internal tannins to form a basic brown complex.

[0010] Furthermore, the process conditions for the alkane fumigation and ammonia fumigation are: relative humidity 70%-80% and temperature 30℃-40℃.

[0011] During the wet smoking stage, at 70%-80% humidity, alkane gases further penetrate, opening up the fiber channels blocked by knots and dense textures, reducing the difference in color and natural color from the base; ammonia combines with lignin tannins and lignin phenolic hydroxyl groups to form stable brown complexes, and the color development reaction is fully carried out under high humidity catalysis, forming a uniform smoked texture and color.

[0012] Furthermore, the process conditions for the balancing treatment are: relative humidity 40%-50% and temperature 20℃-30℃.

[0013] The balancing stage allows the ammonia molecules that have not fully reacted after dry and wet fumigation to slowly complete the complexation and cross-linking, solidifying the internal color structure of the raw board and stabilizing the color; it also balances the dry and wet stress generated by the repeated expansion and contraction of the raw board due to alternating dry fumigation (low humidity) and wet fumigation (high humidity), preventing the raw board from deforming.

[0014] Furthermore, the fumigating gas used in the alkyl fumigation is methane or biogas.

[0015] Furthermore, the fumigation gas used in the ammonia fumigation is ammonia, which is obtained by volatilizing liquid ammonia or an aqueous ammonia solution.

[0016] Furthermore, the ammonia solution has a mass concentration of 25%.

[0017] The activator is any one of tannin solution, hydrogen peroxide solution, gallic acid solution, and ammonium persulfate solution. Furthermore, dry fumigation with alkane, dry fumigation with ammonia, wet fumigation with alkane, wet fumigation with ammonia, and balancing treatment are all completed in a closed space.

[0018] The alkanesamine-ammonia alternating dry and wet fumigation wood flooring prepared by the aforementioned method is characterized in that the wood flooring is a solid wood flooring or a solid wood composite flooring series surface board; the surface board material is any one of oak, hickory, birch, and eucalyptus.

[0019] The beneficial effects of this invention are: 1. This invention opens the pores of the raw wood board through alkyl fumigation, breaks the closed fiber structure of the raw wood board, and ammonia fumigation complexes with the lignin and tannins inside the raw wood board to develop color, and evens out the color depth of the raw wood board knots, uneven colors, and natural color difference areas; dry fumigation is responsible for opening the pores and penetrating, while wet fumigation relies on water vapor to catalyze deep color development. Stable colored complexes are formed inside the raw wood board, making the finished wood flooring less prone to oxidation, fading, color migration and other problems.

[0020] 2. In this invention, a balancing process is set between dry and wet fumigation to release the fiber stress caused by repeated expansion and contraction of the raw board due to the alternation of dry and wet treatment, unify the overall moisture content of the raw board, reduce the risk of warping, shrinkage, and cracking of the finished wood flooring, and balance the concentration of residual alkane and ammonia gas in the raw board during the balancing process, further reducing the color difference of the raw board.

[0021] 3. In this invention, tannin, hydrogen peroxide and other solutions are applied to areas of local color difference in the raw board, and then wet ammonia fumigation is used for secondary modification to specifically deepen the light-colored areas of the raw board, soften the dark knots of the raw board, and improve the modification effect on various raw boards with natural texture differences.

[0022] Appendix Explanation Table 1 is a comparison table of the core performance parameters of the embodiments and comparative examples of the present invention. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the appendix.

[0024] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0025] Example 1 S1: Oak flooring boards are stacked with the surface exposed, and the stacking height is set to 2m.

[0026] S2: After stacking, the raw boards are placed at a relative humidity of 40% and a temperature of 20℃ for 100m. 3The fumigation chamber was filled with methane gas for 8 hours, then transferred to an ammonia fumigation chamber, where it was fumigated at a relative humidity of 40% and a temperature of 20°C for 100 m³. 3 Ammonia gas was released through vaporization in a sealed chamber for 8 hours; relative humidity was controlled at 40% and temperature at 20℃, and equilibration was carried out for 12 hours. Finally, at a relative humidity of 70% and temperature of 30℃, the mixture was fumigated at a depth of 100m². 3 The chamber was filled with methane gas and fumigated for 8 hours at a relative humidity of 70% and a temperature of 30°C. The chamber was 100m² 3 The ammonia gas was released by vaporizing liquid ammonia in a sealed room and fumigated for 8 hours.

[0027] S3: Inspect the raw board and apply tannin solution to areas with color differences on the surface of the raw board.

[0028] S4: The coated raw board is subjected to 100m [temperature conditions] at a relative humidity of 70% and a temperature of 30℃. 3 The wood flooring is fumigated for 8 hours in a sealed room by vaporizing liquid ammonia to release ammonia gas; the relative humidity is controlled at 40% and the temperature at 20℃, and the process is balanced for 12 hours. After the process is completed, the wood flooring is removed and air-dried to obtain the finished wood flooring.

[0029] Example 2 S1: The raw walnut wood flooring boards, whose specifications and dimensions have been determined through mortise and tenoning and sanding, are stacked in an exposed-surface stacking manner, with a stacking height of 2m.

[0030] S2: After stacking, the raw boards are placed at a relative humidity of 50% and a temperature of 30℃ for 100m. 3 The fumigation process involved filling a sealed chamber with commercial biogas for 10 hours, followed by transfer to an ammonia fumigation chamber where, under conditions of 50% relative humidity and 30°C, a 100m³ fumigation process was carried out. 3 20 kg of 25% ammonia solution was placed in an evenly spaced open container inside a sealed room. A fan circulated the volatilized ammonia gas back into the space, and the ammonia was fumigated for 10 hours. The relative humidity was controlled at 40% and the temperature at 20℃, and the room was allowed to equilibrate for 12 hours. Finally, at a relative humidity of 70% and a temperature of 30℃, the solution was applied to a 100m² container. 3 The chamber was filled with methane gas and fumigated for 8 hours at a relative humidity of 70% and a temperature of 30°C. The chamber was 100m² 3 The ammonia gas was released by vaporizing liquid ammonia in a sealed room and fumigated for 8 hours.

[0031] S3: Inspect the raw board and apply hydrogen peroxide solution to areas with color differences on the surface of the raw board.

[0032] S4: The coated raw board is subjected to 100m [temperature] under conditions of 80% relative humidity and 40℃. 3 The wood flooring is fumigated for 8 hours in a sealed room by vaporizing liquid ammonia to release ammonia gas, while maintaining a relative humidity of 50% and a temperature of 30℃. After equilibration for 12 hours, the wood flooring is removed and allowed to air dry naturally to obtain the finished product.

[0033] Example 3 S1: Birch flooring boards with surface grinding, engraving, planing, and embossing styles are stacked using an exposed board stacking method, with a stacking height of 2m.

[0034] S2: The stacked raw boards are fumigated for 8 hours in a 100m³ sealed room filled with methane gas at a relative humidity of 40% and a temperature of 20℃. Then, they are transferred to an ammonia fumigation room and fumigated for 100m³ at a relative humidity of 50% and a temperature of 30℃. 3 20 kg of 25% ammonia solution was placed in an evenly spaced open container inside a sealed room. A fan circulated the volatilized ammonia gas back into the space, and the ammonia was fumigated for 10 hours. The relative humidity was controlled at 40% and the temperature at 20℃, and the room was allowed to equilibrate for 12 hours. Finally, at a relative humidity of 70% and a temperature of 30℃, the solution was applied to a 100m² container. 3 The chamber was filled with methane gas and fumigated for 8 hours at a relative humidity of 70% and a temperature of 30°C. The chamber was 100m² 3 A 20 kg 25% ammonia solution was placed in an evenly spaced open barrel inside a sealed room. A fan circulated the volatilized ammonia gas back into the space, and the ammonia gas was used for fumigation for 10 hours.

[0035] S3: Inspect the raw board and apply gallic acid solution to areas with color differences on the surface of the raw board.

[0036] S4: The coated raw board is subjected to 100m [temperature] under conditions of 80% relative humidity and 40℃. 3 20 kg of 25% ammonia solution is placed in an evenly spaced open barrel inside a sealed room. A fan circulates the volatilized ammonia gas back into the space, and the ammonia gas is used for fumigation for 10 hours. The relative humidity is controlled at 50% and the temperature at 30℃, and the process is balanced for 12 hours. After the process is completed, the wood flooring is directly removed and air-dried to obtain the finished wood flooring.

[0037] Example 4 Eucalyptus wood flooring was used, and ammonium persulfate solution was used as the activator. Other processes and parameters were the same as in Example 1. Comparative Example 1 Oak planks were selected, with relative humidity controlled at 45% and temperature at 25℃. The oak planks were stacked using an exposed-surface stacking method, with stacking heights set at 2m and 100m. 3 A 20 kg 25% ammonia solution is placed in an evenly spaced open barrel inside a sealed room. A fan circulates the volatilized ammonia gas back into the space. The ammonia gas is used for fumigation for 24 hours. After the process is completed, the ammonia gas is removed and the wood flooring is air-dried to obtain the finished wood flooring.

[0038] Comparative Example 2 Oak flooring boards are stacked with the surface exposed, and the stacking height is set to 2m.

[0039] Under a constant relative humidity of 40% and a temperature of 20℃, stacked raw boards are arranged in 100m³ sections. 3The chamber was filled with methane gas and fumigated for 9 hours; then it was transferred to an ammonia fumigation chamber, 100m². 3 Fumigation with ammonia gas released by liquid ammonia vaporization in a sealed room for 9 hours; equilibration treatment for 12 hours; 100m 3 The room was filled with methane gas and fumigated for 9 hours; 100m 3 The ammonia gas was released by vaporizing liquid ammonia in a sealed room and fumigated for 8 hours.

[0040] Explanation of testing indicators: Initial color difference: The smaller the value, the higher the color uniformity of the raw board surface; The aging color difference is the color difference change value after being placed at room temperature and away from light for 6 months. The smaller the value, the better the color stability. The maximum warping deformation is the maximum warping value of the long side of the finished wood flooring; The ammonia residue was determined by gas chromatography to detect the free ammonia content inside the board. Table 1 As shown in Table 1, the initial color difference in Examples 1-4 was 1.6-1.9, and the aging color difference was 0.31-0.38, which was much lower than the initial color difference of 7.3 and the aging color difference of 2.96 in Comparative Example 1, and the initial color difference of 4.9 and the aging color difference of 1.47 in Comparative Example 2. In Comparative Example 1, the traditional ammonia fumigation method alone could not completely eliminate the original color difference of the raw board. In Comparative Example 2, the alkyl fumigation and ammonia fumigation steps were missing, resulting in incomplete color development. Although the aging color difference was improved, problems such as discoloration and fading after prolonged storage still existed.

[0041] In Examples 1-4, the maximum warping deformation was 0.1-0.14 mm, and the residual ammonia was 12.3-13.1 mg / kg; in Comparative Example 1, the maximum warping deformation was 0.5 mm, and the residual ammonia was 42.8 mg / kg; in Comparative Example 2, the maximum warping deformation was 0.16 mm, and the residual ammonia was 18.9 mg / kg. The balancing treatment can not only release the fiber stress inside the raw board, but also slowly release the free ammonia in the pores of the raw board.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing wood flooring by alternating wet and dry fumigation with alkylamine, characterized in that, Includes the following steps: S1: Stack the bare wood flooring boards using an exposed board stacking method, with a stacking height of 2m; S2: The stacked raw boards are subjected to alkane fumigation for 8-10 hours, ammonia fumigation for 8-10 hours, balancing treatment for 12 hours, alkane fumigation for 8-10 hours, ammonia fumigation for 8-10 hours, and balancing treatment for 12-14 hours in sequence. S3: Apply an activator to areas with color differences on the surface of the raw board; S4: After coating, the raw board is subjected to ammonia fumigation for 8-10 hours and equilibration treatment for 12-14 hours.

2. The method for preparing wood flooring by alternating wet and dry fumigation with alkylamine according to claim 1, characterized in that, The process conditions for alkyl fumigation and ammonia fumigation are: relative humidity 40%-50% and temperature 20℃-30℃.

3. The method for preparing wood flooring by alternating wet and dry fumigation with alkylamine according to claim 1, characterized in that, The process conditions for alkane fumigation and ammonia fumigation are: relative humidity 70%-80% and temperature 30℃-40℃.

4. The method for preparing wood flooring by alternating wet and dry fumigation with alkylamine according to claim 1, characterized in that, The process conditions for the balancing process are: relative humidity 40%-50% and temperature 20℃-30℃.

5. The method for preparing wood flooring by alternating wet and dry fumigation with alkylamine according to claim 1, characterized in that, The fumigation gas used in the alkyl fumigation is methane or biogas.

6. The method for preparing wood flooring by alternating wet and dry fumigation with alkylamine according to claim 1, characterized in that, The fumigation gas used in the ammonia fumigation is ammonia, which is obtained by volatilizing liquid ammonia or an aqueous ammonia solution.

7. The method for preparing wood flooring by alternating wet and dry fumigation with alkylamine according to claim 6, characterized in that, The ammonia solution has a mass concentration of 25%.

8. The method for preparing wood flooring by alternating wet and dry fumigation with alkylamine according to claim 1, characterized in that, The activator is any one of tannin, hydrogen peroxide, gallic acid, and ammonium persulfate.

9. The method for preparing wood flooring by alternating wet and dry fumigation with alkylamine according to claim 1, characterized in that, Alkane fumigation (dry), ammonia fumigation (dry), alkane fumigation (wet), ammonia fumigation (wet), and balancing treatment are all completed in a closed space.

10. A wood flooring prepared by the method for preparing wood flooring with alternating dry and wet fumigation according to any one of claims 1-9, characterized in that, The wood flooring is a solid wood flooring or a solid wood composite flooring series surface board; the surface board material is any one of oak, hickory, birch, and eucalyptus.

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