Waterproof reinforced floor and preparation method thereof

Abstract

The application belongs to the field of floor production, and particularly relates to a waterproof reinforced floor and a preparation method. The steps include slicing, hot grinding, drying, paving, hot pressing, board turning cooling, stacking and sanding in sequence. In the hot grinding, solid paraffin is first melted to obtain liquid paraffin, and the temperature is controlled at 55-65 DEG C. The liquid paraffin is directly added into a discharging screw and sent into a grinding chamber body. The liquid paraffin is dispersed into tiny droplets by means of high-speed rotating grinding discs. Meanwhile, the grinding chamber body is connected with an anhydrous ethanol pipe to add anhydrous ethanol into the grinding chamber body, and the anhydrous ethanol is uniformly mixed with separated fibers and adhered to the surface of the fibers. The liquid paraffin is dispersed into tiny droplets by means of the grinding discs in cooperation with the addition of anhydrous ethanol during the hot grinding, which helps the paraffin to better penetrate into the pores of the wood fibers, forms stronger mechanical interlocking and chemical bonding effects, and finally forms a continuous and uniform waterproof layer on the surface of the wood fibers, thereby improving the waterproof effect.

Description

Technical Field

[0001] This invention belongs to the field of flooring production, specifically a waterproof reinforced flooring and its preparation method. Background Technology

[0002] High-density fiberboard (HDF) is a type of wood-based panel, classified by density into low-density, medium-density, and high-density. It can also be classified by raw materials, such as fiberboard, plywood, and particleboard. Fiberboard, in particular, is made by soaking and crushing wood and branches in water, then pressing them together. It is a engineered wood product made from wood fibers or other plant fibers bonded together with urea-formaldehyde resin or other suitable adhesives. Fiberboard is characterized by its fine texture, smooth and attractive surface, and suitability for various finishing processes.

[0003] Existing high-density fiberboard generally lacks waterproofing properties, making it unsuitable for damp areas such as kitchens and bathrooms. Research on waterproofing for MDF has revealed the following:

[0004] CN1235728A discloses a medium-density fiberboard (MDF) and its production method. The MDF is composed of mulberry branch fibers, which contain a waterproofing agent and an adhesive. The production method includes: shaving mulberry branch raw materials; steaming and softening the mulberry branch slices; adding a waterproofing agent to the softened mulberry branch slices; thermally grinding the mulberry branch raw materials into fibers; adding an adhesive at the fiber outlet of the thermal grinding mill; drying the fibers; then assembling the fibers into a pre-pressed form, pre-pressing, and trimming the edges of the board; hot-pressing the board to finally produce the MDF.

[0005] The inventors discovered that when the above-mentioned technical solution is used to produce high-density fiberboard, although the addition of paraffin wax during hot grinding can facilitate the distribution of paraffin wax, the high moisture content in the fiber during hot grinding affects the bonding between the paraffin wax and the fiber. This results in the waterproof layer on the outside of the fiber not being continuous and uniform, and also affects the uniform distribution inside the high-density fiberboard, affecting the mechanical strength, so that the final high-density fiberboard does not have waterproof performance. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the inventors, through practice and summarization, derived the technical solution of this invention, which adopts the following technical solution:

[0007] A method for preparing waterproof reinforced flooring, comprising the following steps:

[0008] S100 slices:

[0009] Plant fiber raw materials are placed on a conveyor belt to remove impurities such as rubber, metal, and stones. The raw materials are then transported to a drum chipper, where they are chipped to obtain wood chips. These chips are then transported to a silo for storage and future use.

[0010] S200 hot milling:

[0011] Fiber separation: Wood chips are preheated to 80-90°C in a preheating chamber and continuously compressed into wood plugs by a feeding screw. The wood plugs are then softened in a cooking tank and fed into a hot mill by a discharge screw for fiber separation to obtain qualified fibers. The pressure in both the cooking tank and the mill chamber is 8-9 Bar.

[0012] First, solid paraffin is melted to obtain liquid paraffin, and the temperature is controlled at 55-65℃. The liquid paraffin is directly added to the unloading screw and sent into the grinding chamber. The high-speed rotating grinding disc disperses it into extremely small droplets. At the same time, an anhydrous ethanol tube is connected to the outside of the grinding chamber to add anhydrous ethanol into the grinding chamber, which is uniformly mixed with the separated fibers and adheres to their surface.

[0013] Sizing: The fibers are transported out of the thermoforming mill and an adhesive is sprayed onto them;

[0014] Paraffin wax addition amount is 7-9 kg / m³ 3 The amount of anhydrous ethanol added is 7-10 L / m³. 3 The adhesive is urea-formaldehyde resin, with an application rate of 220–280 kg / m². 3 ;

[0015] S300 drying:

[0016] After sizing, the moisture content of the fibers is controlled within a certain range by a dryer, maintaining it at 8-12%.

[0017] S400 paving:

[0018] The dried fibers are conveyed to the laying machine by a feeding blower, where the fibers are coarsely formed by vacuum airflow, and then the slab is formed by sweeping rollers and a pre-press.

[0019] S500 hot pressing:

[0020] Under certain temperature and pressure conditions, the slab is pressed and shaped into a rough slab;

[0021] S600, flip-plate cooling:

[0022] After hot pressing, the rough board enters a flipping machine for cooling.

[0023] S700, stacking:

[0024] After molding, the raw boards are stored in the stacking area to cool. The raw boards are stacked separately for 48 hours to allow the moisture inside the board to be evenly distributed and to reach equilibrium with the atmospheric humidity, thus completing the conditioning treatment.

[0025] S800, Sanding:

[0026] The surface of the board is sanded using a sander, which makes the surface smooth and increases its strength, while ensuring uniform thickness.

[0027] A method for preparing waterproof reinforced flooring, comprising the following steps:

[0028] S100 slices:

[0029] Plant fiber raw materials are placed on a conveyor belt to remove impurities such as rubber, metal, and stones. The raw materials are then transported to a drum chipper, where they are chipped to obtain wood chips. These chips are then transported to a silo for storage and future use.

[0030] S200 hot milling:

[0031] Fiber separation: Wood chips are preheated to 80-90°C in a preheating chamber and continuously compressed into wood plugs by a feeding screw. The wood plugs are then softened in a cooking tank and fed into a hot mill by a discharge screw for fiber separation to obtain qualified fibers. The pressure in both the cooking tank and the mill chamber is 8-9 Bar.

[0032] S300, Modified

[0033] Under closed conditions, a high-temperature and high-pressure vapor-liquid two-phase system is used to treat the fiber once, filtering out the liquid phase components. The temperature is 110-130℃ and the pressure is 8-10 Bar.

[0034] The fibers are treated with microwaves at a power of 3-5kW, a frequency of 2450MHz, and a treatment time of 1-2s to obtain activated fibers.

[0035] The activated fibers are spread evenly with a thickness of 3-5 mm, and then subjected to plasma modification treatment in a closed space under a nitrogen and fluorine atmosphere to obtain modified fibers.

[0036] Next, the modified fiber was placed in an ethanol aqueous solution, and KH-550 was added at a rate of 5-10% of the modified fiber amount. The mixture was stirred for 2-3 hours at a reaction temperature of 50-60℃, and then filtered to obtain a solid product.

[0037] S400, application of adhesive:

[0038] The fiber is sprayed with an adhesive, which is urea-formaldehyde resin, at a rate of 220–280 kg / m². 3 The reaction is carried out at a constant temperature for 2-4 hours, with the reaction temperature being 60-80℃.

[0039] S500 drying:

[0040] After sizing, the moisture content of the fibers is controlled within a certain range by a dryer, maintaining it at 8-12%.

[0041] S600 Paving:

[0042] The dried fibers are conveyed to the laying machine by a feeding blower, where the fibers are coarsely formed by vacuum airflow, and then the slab is formed by sweeping rollers and a pre-press.

[0043] S700 hot pressing:

[0044] Under certain temperature and pressure conditions, the slab is pressed and shaped into a rough slab;

[0045] S800, flip-plate cooling:

[0046] After hot pressing, the rough board enters a flipping machine for cooling.

[0047] S900, stacking:

[0048] After molding, the raw boards are stored in the stacking area to cool. The raw boards are stacked separately for 48 hours to allow the moisture inside the board to be evenly distributed and to reach equilibrium with the atmospheric humidity, thus completing the conditioning treatment.

[0049] S1000, Sanding:

[0050] The surface of the board is sanded using a sander, which makes the surface smooth and increases its strength, while ensuring uniform thickness.

[0051] Preferably, in the enclosed space, nitrogen gas is introduced into the interior to fully replace the internal air at least twice. Then, a 1:(1-3) mixture of nitrogen and fluorine gas is introduced to replace the internal nitrogen gas. After reacting for 1.5-2 hours, nitrogen gas is introduced again to fully replace the gas after the reaction.

[0052] Preferably, when the nitrogen gas fully replaces the gas after the internal reaction, the internal temperature is raised to 120-140°C and maintained at this temperature for 0.5-1 hour, and gas replacement is maintained throughout the heating stage, ultimately obtaining modified fibers.

[0053] Preferably, the plant fiber raw materials include pine, poplar, miscellaneous wood, small-diameter logs, branches, logging and processing residues, and non-woody plant fiber raw materials;

[0054] The slices are then filtered, and the filtering process is as follows:

[0055] The chips produced by the chipper are of varying sizes and still contain various impurities. After being screened by a vibrating screen, the large wood chips and impurities are removed, and suitable chips are obtained and fed to the hot mill via a feeding screw.

[0056] The wood chips are 15-35mm long, 15-25mm wide, and 3-5mm thick, with a moisture content of 35-50%.

[0057] Preferably, the adhesive spraying employs a protective variable-diameter sprayer, comprising:

[0058] The glue spray nozzle has an external hose connected to the glue storage tank via its glue inlet.

[0059] The variable diameter protection assembly includes a micro motor fixedly installed on the outside of the spray nozzle and an adjusting sleeve threaded onto the outlet of the spray nozzle, with a rotating ring installed on the adjusting sleeve.

[0060] The isolation plate is located on top of the fiber, and a conveyor belt for conveying the fiber is set below the isolation plate. A holding trough is set on the conveyor belt, and an air vent is set at the bottom of the holding trough.

[0061] Among them, the output end of the micro motor is equipped with a cross shaft, a gear disk is mounted on the cross shaft, a support tray is provided on the top of the gear disk, a toothed ring that meshes with the gear disk is provided on the top side of the adjusting sleeve, and the support tray supports the top of the adjusting sleeve.

[0062] The rotating ring and the spray nozzle are circumferentially equipped with multiple high-pressure air pipes, all of which are deflected. The high-pressure air pipes are connected to a high-pressure air source and a negative pressure generator through a three-way solenoid valve. The projection of the multiple high-pressure air pipes on the horizontal plane is distributed in a vortex shape.

[0063] Preferably, a connecting rod is rotatably mounted on the side of the rotating ring, and one end of the connecting rod is rotatably mounted on the high-pressure air pipe.

[0064] Preferably, the dryer employs a two-stage drying system;

[0065] The diameter of the primary drying pipe is 2m, the length of the drying pipe is 40-45m, and the temperature of the primary drying medium is 150-160℃.

[0066] The diameter of the secondary drying pipe is 1m, the length of the drying pipe is 75-85m, and the end of the pipe is connected to a cyclone separator to separate the dry fiber from the air. The temperature of the secondary drying medium is 85-100 degrees Celsius.

[0067] The entire drying time is 4-5 seconds, and the airflow speed is 20-30 m / s.

[0068] Preferably, the double-sided sanding allowance of the rough board is 0.5-1.2mm;

[0069] The sanding equipment selected is a double-sided wide-band sander;

[0070] Coarse sand: Use 30-50 mesh sanding belts for sanding rollers 1 and 2, 60-100 mesh sanding belts for sanding rollers 3 and 4, and 100-120 mesh sanding belts for sanding rollers 5 and 6;

[0071] Fine sand: Use 120-180 mesh sanding belts for sanding rollers 7 and 8, and 180-220 mesh sanding belts for sanding rollers 9 and 10;

[0072] Fine sand: Polished by polishing rollers;

[0073] The proportion of each abrasive roller's cutting amount to the total abrasive cutting amount is as follows: 60-70% for coarse sand, 20% for fine sand, <10% for refined sand, and the remainder is less than or equal to 5%.

[0074] Compared with the prior art, the present invention has the following beneficial effects:

[0075] 1. One method of the present invention: by adding anhydrous ethanol during hot grinding to disperse liquid paraffin into extremely small droplets with the grinding disc, it helps the paraffin to better penetrate into the pores of wood fibers, forming stronger mechanical interlocking and chemical bonding, and finally forming a continuous and uniform waterproof layer on the surface of wood fibers, thereby improving the waterproof effect.

[0076] 2. Another method of this invention: After thermal grinding, the fibers undergo high-pressure, high-temperature gas-liquid two-phase treatment, introducing a large number of hydroxyl groups onto the wood surface, providing more reaction sites for subsequent microwave treatment. Traditional microwave treatment heats the fibers, serving a drying function. When applied to this method, research has shown that it also generates pressure within the fibers. This pressure change helps disrupt the wood's cellular structure. Simultaneously, microwave treatment alters the electric field distribution and molecular motion within the fibers, exposing more functional groups such as hydroxyl groups that were originally encased within the cell walls. Subsequently, plasma technology is used to treat the wood fiber surface, introducing a large number of active groups and defects. These active groups and defects facilitate the adsorption and reaction of subsequent fluorinating agents. The introduction of fluorinating agents onto the plasma-treated fiber surface leads to the formation of carbon-fluorine bonds through a plasma-induced chemical reaction. The introduction of these carbon-fluorine bonds significantly improves the hydrophobic properties of the fibers and significantly enhances the interfacial bonding strength of the wood. This enhanced interfacial bonding helps resist external stress and prevents the wood from cracking or breaking. Then, through the KH-550 reaction, combined with the subsequent spraying of urea-formaldehyde resin adhesive, the two are effectively combined, which can achieve an absolute moisture-proof effect on the fiber itself and also ensure the waterproof performance of the MDF.

[0077] 3. This invention employs a double-sided sanding process, which involves sequentially applying coarse sanding, fine sanding, and polishing sanding to reduce the thickness tolerance of the board, eliminate surface defects, and make the board uniform in thickness and smooth and flat on the surface, facilitating its use and surface decoration.

[0078] 4. This invention employs a novel adhesive spraying method, utilizing a protective spraying technique. High-pressure air pipes are arranged in a vortex pattern on the outside of the spraying path to form an airflow isolation shield. Inside this shield, a relatively stable air pressure field is created. Spraying adhesive within this air pressure field ensures high quality, high adhesive utilization, and uniform spraying. During spraying, a negative pressure generator generates a vortex airflow through the high-pressure air pipes, creating a negative pressure field that keeps the fibers within the coverage area loose / floating, facilitating uniform adhesive coverage. After spraying, a three-way solenoid valve switches to connect the high-pressure air source to the high-pressure air pipes. Simultaneously, a micro-motor adjusts the position of the bottom of the high-pressure air pipes, reducing the coverage area at the bottom and changing the direction of the negative pressure field. This causes the sprayed fibers to fall back to their original position. It is important to note that the fibers must remain stationary throughout the spraying process; otherwise, they will float. This addresses the issue of mis-spraying caused by direct spraying, which often results in fiber deviation.

[0079] 5. This invention employs a two-stage drying method:

[0080] 1) Staged drying improves drying efficiency.

[0081] The two-stage drying system achieves a gradual reduction in the moisture content of wet fibers through primary and secondary drying stages. The primary drying pipe has a large diameter and moderate length, and a relatively high medium temperature (150-160℃), enabling it to quickly remove a large amount of moisture from the fiber surface. Subsequently, the secondary drying pipe, with a lower medium temperature (85-100℃) and a longer path (75-85 meters), further removes moisture from the inside of the fibers, ensuring that the final moisture content meets the requirements before hot pressing (8%-12%). This staged drying method improves drying efficiency and shortens the overall drying time (4-5 seconds).

[0082] 2) Precise control improves drying effect

[0083] The two-stage drying system allows for more precise control of parameters such as temperature, humidity, and airflow velocity during the drying process. The rapid heating in the first-stage drying helps to quickly evaporate moisture from the fiber surface, while the lower temperature and longer duration in the second-stage drying facilitate the slow release of moisture from within the fiber, avoiding fiber damage or internal stress concentration caused by high-temperature rapid drying. Furthermore, by adjusting the airflow velocity (20-30 m / s), uniform heating and cooling of the wet fibers during the drying process can be ensured, further improving the drying effect.

[0084] 3) Reduce energy consumption and improve energy efficiency.

[0085] The secondary drying system can utilize the waste heat from the primary drying as a preheating source, reducing the amount of fresh hot air used, which can improve energy efficiency and reduce production costs.

[0086] 4) Prevent clumping and improve conveying and paving efficiency.

[0087] During the drying process, wet fibers are prone to clumping due to moisture evaporation, affecting subsequent conveying and laying results. The two-stage drying system effectively avoids fiber clumping by precisely controlling drying conditions and employing a phased drying method. The rapid heating in the first stage of drying helps break down moisture bridges between fibers, while the lower temperature and longer duration in the second stage promote further loosening and dispersion of the fibers. Furthermore, the use of a cyclone separator effectively separates dry fibers from air, further improving fiber looseness and uniformity.

[0088] 5) Improve product quality

[0089] The moisture content of wet fibers treated with secondary drying is more uniform and stable, which is beneficial for the smooth progress of subsequent hot pressing and laying processes. At the same time, the improved drying effect and reduced fiber clumping also improve the quality and stability of the final product. Attached Figure Description

[0090] Figure 1 One embodiment of the preparation method;

[0091] Figure 2 Another preparation method is described;

[0092] Figure 3 This is a front view of the structure of a protective variable diameter adhesive sprayer;

[0093] Figure 4 This is the front view of the glue spray nozzle;

[0094] Figure 5 for Figure 4 A magnified view of a section at point A in the middle;

[0095] Figure 6 This is a bottom view of the high-pressure air pipe;

[0096] Figure 7 This is a top view of the isolation panel. Detailed Implementation

[0097] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0098] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0099] Example 1

[0100] like Figure 1 As shown, a method for preparing waterproof reinforced flooring includes the following steps:

[0101] S100 slices:

[0102] Plant fiber raw materials are placed on a conveyor belt to remove impurities such as rubber, metal, and stones. The raw materials are then transported to a drum chipper, where they are chipped to obtain wood chips. These chips are then transported to a silo for storage and future use.

[0103] S200 hot milling:

[0104] Fiber separation: Wood chips are preheated to 80-90°C in a preheating chamber and continuously compressed into wood plugs by a feeding screw. The wood plugs are then softened in a cooking tank and fed into a hot mill by a discharge screw for fiber separation to obtain qualified fibers. The pressure in both the cooking tank and the mill chamber is 8-9 Bar.

[0105] First, solid paraffin is melted to obtain liquid paraffin, and the temperature is controlled at 55-65℃. The liquid paraffin is directly added to the unloading screw and sent into the grinding chamber. The high-speed rotating grinding disc disperses it into extremely small droplets. At the same time, an anhydrous ethanol tube is connected to the outside of the grinding chamber to add anhydrous ethanol into the grinding chamber, which is uniformly mixed with the separated fibers and adheres to their surface.

[0106] Sizing: The fibers are transported out of the thermoforming mill and an adhesive is sprayed onto them;

[0107] Paraffin wax addition amount is 7-9 kg / m³ 3 The amount of anhydrous ethanol added is 7-10 L / m³. 3 The adhesive is urea-formaldehyde resin, with an application rate of 220–280 kg / m². 3 ;

[0108] S300 drying:

[0109] After sizing, the moisture content of the fibers is controlled within a certain range by a dryer, maintaining it at 8-12%.

[0110] S400 paving:

[0111] The dried fibers are conveyed to the laying machine by a feeding blower, where the fibers are coarsely formed by vacuum airflow, and then the slab is formed by sweeping rollers and a pre-press.

[0112] S500 hot pressing:

[0113] Under certain temperature and pressure conditions, the slab is pressed and shaped into a rough slab;

[0114] Hot pressing is one of the most important processes in the manufacturing of flooring substrates. It uses high temperature and high pressure to evaporate the moisture in the board blank, cure the adhesive, and compact the board blank, causing a series of physicochemical changes in the components of the raw materials to form a raw board that meets the quality requirements.

[0115] Temperatures in the high-pressure and medium-pressure zones are generally set at 220–250℃, while temperatures in the low-pressure zone are generally set at 190℃. The maximum pressure in the high-pressure zone can typically reach 5.0 MPa. The pressure in the medium-pressure zone is generally between 2.5 and 4.0 MPa, and the pressure in the low-pressure zone is typically below 2.0 MPa.

[0116] S600, flip-plate cooling:

[0117] After hot pressing, the rough boards enter the flipping machine for cooling. The purpose of cooling is to prevent the adhesive from hydrolyzing under continuous high temperature after the rough boards are removed from the hot pressing, thereby maintaining the board's high strength.

[0118] S700, stacking:

[0119] After molding, the raw boards are stored in the stacking area to cool. The raw boards are stacked separately for 48 hours to allow the moisture inside the board to be evenly distributed and to reach equilibrium with the atmospheric humidity, thus completing the conditioning treatment.

[0120] S800, Sanding:

[0121] The surface of the board is sanded using a sander, which makes the surface smooth and increases its strength, while ensuring uniform thickness.

[0122] It also includes hot-pressed decorative paper, which has wear-resistant and waterproof properties and uses traditional materials and processes, so it will not be elaborated further here.

[0123] It also includes the steps of trimming the longitudinal and transverse edges:

[0124] Trim off any uneven, loose, or inferior board edges according to the specified dimensions to make it a board of the designated size.

[0125] Edge trimming requirements: The four sides of the trimmed board should be straight and neat, with smooth cut edges. The length and width deviations should not be negative, and the straightness of the edges should not exceed the national standard.

[0126] Edge trimming equipment – ​​horizontal edge trimming machine and vertical edge trimming machine.

[0127] It also includes seam cutting, where a grooving machine is used to cut seams at the edges. This process is also a traditional process, so it will not be elaborated on here.

[0128] Inspection: The raw boards are inspected and graded according to the relevant standards for flooring substrates.

[0129] Product inspection is divided into:

[0130] Specification and dimensional inspection, including: thickness tolerance, width tolerance, diagonal tolerance, and warpage.

[0131] Appearance quality inspection includes: localized softness, edge and corner defects, oil stains, water spots, and delamination and bubbling.

[0132] Physical and mechanical property testing includes: static bending strength, internal bond strength, and surface bond strength.

[0133] Other indicators include density, moisture content, 24-hour water absorption thickness expansion rate, and formaldehyde release.

[0134] Example 2

[0135] like Figure 2 As shown, a method for preparing waterproof reinforced flooring includes the following steps:

[0136] S100 slices:

[0137] Plant fiber raw materials are placed on a conveyor belt to remove impurities such as rubber, metal, and stones. The raw materials are then transported to a drum chipper, where they are chipped to obtain wood chips. These chips are then transported to a silo for storage and future use.

[0138] S200 hot milling:

[0139] Fiber separation: Wood chips are preheated to 80-90°C in a preheating chamber and continuously compressed into wood plugs by a feeding screw. The wood plugs are then softened in a cooking tank and fed into a hot mill by a discharge screw for fiber separation to obtain qualified fibers. The pressure in both the cooking tank and the mill chamber is 8-9 Bar.

[0140] S300, Modified

[0141] Under closed conditions, a high-temperature and high-pressure vapor-liquid two-phase system is used to process the fiber once, filtering out the liquid phase components to obtain fibers with a moisture content of 15-20%, at a temperature of 110-130℃ and a pressure of 8-10 Bar.

[0142] The fibers are treated with microwaves at a power of 3-5kW, a frequency of 2450MHz, and a treatment time of 1-2s to obtain activated fibers.

[0143] Excessive power can cause a sharp rise in the internal temperature of the material, leading to problems such as cracking, deformation, or even coking; while insufficient power will fail to achieve the desired processing effect.

[0144] The activated fibers are spread evenly with a thickness of 3-5 mm, and then subjected to plasma modification treatment in a closed space under a nitrogen and fluorine atmosphere to obtain modified fibers.

[0145] In a closed space, nitrogen gas is introduced into the interior to fully replace the internal air at least twice. Then, a 1:(1-3) mixture of nitrogen and fluorine gas is introduced to replace the nitrogen gas inside. After reacting for 1.5-2 hours, nitrogen gas is introduced again to fully replace the gas inside after the reaction. Our company uses a 1:2.5 mixture.

[0146] When nitrogen fully replaces the gas after the internal reaction, the internal temperature is raised to 120-140℃ and maintained at this temperature for 0.5-1h. The preferred temperature is 135℃, and gas replacement is maintained throughout the heating stage to finally obtain modified fibers.

[0147] Next, the modified fiber is placed in an ethanol aqueous solution, and KH-550 is added. The amount added is 5-10% of the modified fiber, preferably 6.5%. The mixture is stirred and reacted for 2-3 hours at a temperature of 50-60℃, preferably 55℃. The solid product is then obtained by filtration.

[0148] S400, application of adhesive:

[0149] The fiber is sprayed with an adhesive, which is urea-formaldehyde resin, at a rate of 220–280 kg / m². 3 The reaction is carried out at a constant temperature for 2-4 hours, with the reaction temperature being 60-80℃, preferably 70℃.

[0150] S500 drying:

[0151] After sizing, the moisture content of the fibers is controlled within a certain range by a dryer, maintaining it at 8-12%.

[0152] S600 Paving:

[0153] The dried fibers are conveyed to the laying machine by a feeding blower, where the fibers are coarsely formed by vacuum airflow, and then the slab is formed by sweeping rollers and a pre-press.

[0154] S700 hot pressing:

[0155] Under certain temperature and pressure conditions, the slab is pressed and shaped into a rough slab;

[0156] S800, flip-plate cooling:

[0157] After hot pressing, the rough board enters a flipping machine for cooling.

[0158] S900, stacking:

[0159] After molding, the raw boards are stored in the stacking area to cool. The raw boards are stacked separately for 48 hours to allow the moisture inside the board to be evenly distributed and to reach equilibrium with the atmospheric humidity, thus completing the conditioning treatment.

[0160] S1000, Sanding:

[0161] The surface of the board is sanded using a sander, which makes the surface smooth and increases its strength, while ensuring uniform thickness.

[0162] It also includes hot-pressed decorative paper, which has wear-resistant and waterproof properties and uses traditional materials and processes, so it will not be elaborated further here.

[0163] It also includes hot-pressed decorative paper, which has wear-resistant and waterproof properties and uses traditional materials and processes, so it will not be elaborated further here.

[0164] It also includes the steps of trimming the longitudinal and transverse edges:

[0165] Trim off any uneven, loose, or inferior board edges according to the specified dimensions to make it a board of the designated size.

[0166] Edge trimming requirements: The four sides of the trimmed board should be straight and neat, with smooth cut edges. The length and width deviations should not be negative, and the straightness of the edges should not exceed the national standard.

[0167] Edge trimming equipment – ​​horizontal edge trimming machine and vertical edge trimming machine.

[0168] It also includes seam cutting, where a grooving machine is used to cut seams at the edges. This process is also a traditional process, so it will not be elaborated on here.

[0169] Inspection: The raw boards are inspected and graded according to the relevant standards for flooring substrates.

[0170] Product inspection is divided into:

[0171] Specification and dimensional inspection, including: thickness tolerance, width tolerance, diagonal tolerance, and warpage.

[0172] Appearance quality inspection includes: localized softness, edge and corner defects, oil stains, water spots, and delamination and bubbling.

[0173] Physical and mechanical property testing includes: static bending strength, internal bond strength, and surface bond strength.

[0174] Other indicators include density, moisture content, 24-hour water absorption thickness expansion rate, and formaldehyde release.

[0175] Example 3

[0176] The plant fiber raw materials include pine, poplar, miscellaneous wood, small-diameter logs, branches, logging and processing residues, and non-woody plant fiber raw materials.

[0177] The slices are then filtered, and the filtering process is as follows:

[0178] The chips produced by the chipper are of varying sizes and still contain various impurities. After being screened by a vibrating screen, the large wood chips and impurities are removed, and suitable chips are obtained and fed to the hot mill via a feeding screw.

[0179] The wood chips are 15-35mm long, 15-25mm wide, and 3-5mm thick, with a moisture content of 35-50%.

[0180] Example 4

[0181] The dryer employs a two-stage drying system.

[0182] The diameter of the primary drying pipe is 2m, the length of the drying pipe is 40-45m, preferably 45m, and the temperature of the primary drying medium is 150-160℃.

[0183] The diameter of the secondary drying pipe is 1m, and the length of the drying pipe is 75-85 meters, preferably 80 meters. The end of the pipe is connected to a cyclone separator to separate the dry fiber from the air. The temperature of the secondary drying medium is 85-100 degrees Celsius.

[0184] The entire drying time is 4-5 seconds, and the airflow speed is 20-30 m / s.

[0185] For a primary drying duct, when the diameter is less than 2m, the reduced diameter leads to a narrower airflow channel, increasing airflow resistance within the duct. This not only increases fan energy consumption but also affects airflow uniformity and stability, ultimately impacting drying efficiency. Increased airflow resistance may also slow down airflow velocity, reducing the contact time between fibers and hot air, thus affecting moisture evaporation rate and drying efficiency.

[0186] When the diameter exceeds 2 meters, the increased diameter means more hot air is needed to fill the pipe, thus increasing energy consumption. A larger pipe area also means more heat loss, further reducing energy efficiency. Increasing the diameter directly leads to higher pipe material and manufacturing costs, while also increasing the difficulty and cost of installation and maintenance. Although a larger diameter provides a larger airflow channel, it also results in uneven airflow distribution within the pipe, affecting the uniformity of the drying effect.

[0187] When the pipe is too long, the increased residence time of the fibers within it prolongs the drying process, making fibers more susceptible to damage or internal stress concentration. This leads to reduced production line speed and decreased capacity. A prolonged drying process consumes more hot air and energy, increasing production costs. Furthermore, excessively long pipes occupy more production space, increasing equipment footprint and investment costs.

[0188] If the pipe is too short, it may not provide enough drying time, causing the fiber moisture content to fail to meet the requirements before hot pressing. To complete the drying process in a short time, the airflow velocity needs to be increased. However, excessively high airflow velocities can lead to uneven fiber distribution within the pipe or static electricity.

[0189] When the medium temperature is below 150-160℃, the heat transfer efficiency of the hot air decreases, thus prolonging the drying time and reducing drying efficiency. To compensate for the reduced drying efficiency caused by insufficient temperature, it is necessary to increase the hot air flow rate or raise the heating temperature, thereby increasing energy consumption. Excessively low temperatures prevent the complete evaporation of moisture from the fibers, affecting the quality and stability of the product.

[0190] When the medium temperature exceeds 150-160℃, excessively high temperatures may cause chemical reactions such as pyrolysis and oxidation on the fiber surface, leading to fiber damage and performance degradation. Although high temperatures can improve drying efficiency, they also increase the energy consumption and operating costs of heating equipment. Furthermore, they can easily lead to the risk of premature curing of the adhesive.

[0191] Similarly, for the second stage of the drying pipeline, this parameter setting can ensure the final moisture content and avoid excessive drying efficiency leading to fiber damage and internal stress concentration, which would affect the mechanical properties of the raw board.

[0192] Example 5

[0193] The sanding equipment selected is a double-sided wide-band sander;

[0194] Coarse sand: Use 30-50 mesh sanding belts for sanding rollers 1 and 2, 60-100 mesh sanding belts for sanding rollers 3 and 4, and 100-120 mesh sanding belts for sanding rollers 5 and 6;

[0195] Fine sand: Use 120-180 mesh sanding belts for sanding rollers 7 and 8, and 180-220 mesh sanding belts for sanding rollers 9 and 10;

[0196] Fine sand: Polished by polishing rollers;

[0197] The proportion of each abrasive roller's cutting amount to the total abrasive cutting amount is as follows: 60-70% for coarse sand, 20% for fine sand, <10% for refined sand, and the remainder is less than or equal to 5%.

[0198] Example 6

[0199] Among them, such as Figures 3 to 7 As shown, the adhesive spraying uses a protective variable diameter sprayer, including:

[0200] Spray nozzle 1, the glue inlet of spray nozzle 1 is connected to the glue storage tank via an external hose;

[0201] The variable diameter protection assembly includes a micro motor 2 fixedly installed on the outside of the spray head 1 and an adjusting sleeve 3 threadedly installed at the outlet of the spray head 1, with a rotating ring 4 installed on the adjusting sleeve 3.

[0202] The isolation plate 5 is located at the top of the conveying fiber. The isolation plate 5 is provided with a channel for spraying glue. The fiber thickness is 4-8mm, preferably 5mm. A conveyor belt for conveying fiber is provided below the isolation plate 5. A holding trough is provided on the conveyor belt, and a ventilation port is provided at the bottom of the holding trough. The isolation plate 5 and the conveyor belt can be in contact or have a certain gap, and the gap is generally selected to be 1-2mm. The holding trough is used to cooperate with the channel for spraying glue on the fiber in the trough.

[0203] Among them, the output end of the micro motor 2 is equipped with a cross shaft 21, a gear disk 22 is mounted on the cross shaft 21, a support tray 23 is provided on the top of the gear disk 22, and a toothed ring 31 that meshes with the gear disk 22 is provided on the top side of the adjusting sleeve 3. The support tray 23 supports the top of the adjusting sleeve 3.

[0204] Multiple high-pressure air pipes 8, all of which are deflected, are arranged circumferentially on the side of the rotating ring 4 and the spray nozzle 1. The high-pressure air pipes 8 are connected to a high-pressure air source 6 and a negative pressure generator 7 through a three-way solenoid valve. The projection of the multiple high-pressure air pipes 8 on the horizontal plane is distributed in a vortex shape.

[0205] A connecting rod 7 is rotatably mounted on the side of the rotating ring 4, and one end of the connecting rod 7 is rotatably mounted on the high-pressure air pipe 5. The bottom position of the high-pressure air pipe 5 is adjusted by adjusting the distance between the adjusting sleeve 3 and the glue outlet at the bottom of the spray head 1, thereby achieving outward or inward extension and adjustment of the coverage area.

[0206] A novel adhesive spraying method is employed, utilizing high-pressure air pipes 8 arranged in a vortex pattern on the outside of the spraying path to form an airflow isolation hood. Inside this hood, a relatively stable air pressure field is created. Spraying adhesive within this air pressure field ensures spraying quality, high adhesive utilization, and uniform application. During spraying, the air inlets of the high-pressure air pipes are distributed outwards, and the negative pressure generator generates a vortex airflow through the high-pressure air pipes. The air pressure field is an upward negative pressure state, which keeps the fibers within the coverage area loose / floating (high looseness approaching floating). The adhesive is homogenized within the air pressure field. The fiber is dispersed, unlike traditional spraying which cannot achieve uniform coverage. This method helps the adhesive to evenly cover the fibers. After spraying, the three-way solenoid valve switches to connect the high-pressure air source and the high-pressure air pipe. At the same time, the micro motor adjusts the position of the bottom of the high-pressure air pipe, making the bottom coverage area smaller. This causes the negative pressure direction of the air pressure field to change, resulting in a downward negative pressure state. This causes the sprayed fibers to fall back to their original position. It is important to note that the fibers must remain stationary throughout the entire spraying process; otherwise, the fibers will float and scatter. This method solves the problem of fiber deviation and false spraying that can easily occur with traditional direct spraying.

[0207] Waterproof performance and durability tests:

[0208] Waterproof performance and durability tests:

[0209] 1. Simulate real-life scenarios:

[0210] Four floorboards were spliced ​​together. A 500*300mm bottomless transparent box frame was placed on the upper surface of the spliced ​​area, and the box was sealed with water around the edges. Room temperature water (20±5℃) was then poured into the box frame to a depth of 50±5mm. The box was left to stand for 72±1 hours. After draining the water and wiping the surface dry, the edges of the spliced ​​area were observed for swelling or bulging. The comparative example showed bulging / swelling in some areas.

[0211] 2. Experimental Standard Testing

[0212] According to Method 2 of 4.5 Water Absorption Thickness Swelling Rate in GB / T17657-2013, the flooring obtained by Examples 1 to 3 has a groove water absorption thickness swelling rate of ≤4%, which is significantly better than the ≤8% required by GB / T18102-2021. The comparative example under the same method has a groove water absorption thickness swelling rate of ≤8%.

[0213] Based on the above, the water absorption thickness swelling rate is an important evaluation criterion for the waterproofness of laminate flooring. The highest requirement for this index in the Chinese national standard for laminate flooring products, GB / T18102-2021, is ≤8%, which is basically equivalent to the requirement in the European standard for laminate flooring products, EN 13329:2016+A2:2021. Method 2 in section 4.5 of GB / T17657-2013 regarding water absorption thickness swelling rate is also basically equivalent to that in ES ISO 24336:2005.

[0214] Therefore, the waterproof performance of the waterproof engineered flooring obtained in the above embodiments is significantly better than that of the Chinese national standard and European standard for engineered flooring.

[0215] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. The substitutions may be replacements of some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made to the technical solutions and inventive concepts of the present invention should all be covered within the scope of protection of the present invention.

Claims

1. A preparation method of waterproof reinforced floor, comprising the following steps in sequence: slicing, hot grinding, drying, paving, hot pressing, turning board cooling, stacking and sanding; characterized in that The hot grinding step is as follows: Fiber separation: the wood chips are preheated to 80-90 DEG C in a preheating bin, continuously compressed into wood plugs by a feeding screw, and then softened in a cooking cylinder, and the wood plugs are sent into a hot grinder by a discharging screw after being softened, so that qualified fibers are obtained, and the pressure of the cooking cylinder and the grinding chamber is 8-9 Bar; First, solid paraffin is melted to obtain liquid paraffin, and the temperature is controlled at 55-65 DEG C, then the liquid paraffin is directly added into the discharging screw and sent into the grinding chamber, and the paraffin is dispersed into tiny droplets by high-speed rotating grinding disc, and at the same time, the grinding chamber is connected with an anhydrous ethanol pipe to add anhydrous ethanol into the grinding chamber, so that the separated fibers are uniformly mixed and adhered to the surface thereof; Gluing: the fibers are transported out of the hot grinder, and the fibers are sprayed with adhesive; The paraffin addition amount is 7-9 kg / m³, the anhydrous ethanol addition amount is 7-10 L / m³, the adhesive is urea-formaldehyde resin glue, and the gluing amount is 220-280 kg / m³; The adhesive spraying adopts a protective variable-diameter glue sprayer, which comprises: A glue spraying head, a hose connected with the glue inlet of the glue spraying head and a glue storage tank in communication; A variable-diameter protective assembly, comprising a micro motor fixedly installed on the outside of the glue spraying head and an adjusting sleeve threadedly installed at the glue outlet of the glue spraying head, and a rotating ring installed on the adjusting sleeve; An isolation plate, which is located on the top of the fibers, and a conveying belt below the isolation plate for conveying the fibers, and a holding groove provided on the conveying belt, and an air exchange opening provided at the bottom of the holding groove; Wherein, the output end of the micro motor is provided with a cross shaft, the cross shaft is provided with a gear disc, the top of the gear disc is provided with a supporting disc, the top of the adjusting sleeve is provided with a gear ring engaged with the gear disc, and the supporting disc is supported on the top of the adjusting sleeve; The side of the rotating ring and the glue spraying head is circumferentially provided with a plurality of deflected high-pressure air pipes, the high-pressure air pipes are connected with a high-pressure gas source and a negative pressure generator through a three-way electromagnetic valve, and the projections of the plurality of high-pressure air pipes on the horizontal plane are distributed in a vortex shape.

2. The method of claim 1, wherein the waterproofing layer is formed by applying a waterproofing agent to the surface of the core layer. The sliced wood chips are screened, and the screening process is as follows: The wood chips cut by the chipper are of different sizes and still contain various impurities, the large wood chips and impurities are removed through the screening of a shaking screen, and the obtained wood chips are suitable for use and are sent to the hot grinder through a feeding screw; The wood chip specifications are 15-35 mm in length, 15-25 mm in width and 3-5 mm in thickness, and the wood chip moisture content is 35-50%.

3. The method of claim 1, wherein the waterproofing layer is formed by applying a waterproofing agent to the surface of the core layer. The dryers adopt a two-stage drying system; 4. The method of claim 1, wherein the waterproofing layer is formed by applying a waterproofing agent to the surface of the core layer. The first-stage drying pipeline has a diameter of 2 m and a length of 40-45 m, and the first-stage drying medium temperature is 150-160 DEG C; The second-stage drying pipeline has a diameter of 1 m and a length of 75-85 m, and the pipeline end is connected with a cyclone separator to separate the dry fibers from the air, and the second-stage drying medium temperature is 85-100 DEG C; The whole drying time is 4-5 s, and the airflow speed is 20-30 m / s. The double-sided sanding allowance of the rough board is 0.5-1.2 mm.

5. The method of claim 1, wherein the waterproofing layer is formed by applying a waterproofing agent to the surface of the core layer. ​ The sanding equipment is selected as a double-sided wide-band sanding machine; Coarse sand: sand rollers 1 and 2 use 30-50 mesh sand belts, sand rollers 3 and 4 use 60-100 mesh sand belts, and sand rollers 5 and 6 use 100-120 mesh sand belts; Fine sand: sand rollers 7 and 8 use 120-180 mesh sand belts, and sand rollers 9 and 10 use 180-220 mesh sand belts; Fine sand: sand rollers 7 and 8 use 120-180 mesh sand belts, and sand rollers 9 and 10 use 180-220 mesh sand belts; Fine sand: sand rollers 7 and 8 use 120-180 mesh sand belts, and sand rollers 9 and 10 use 180-220 mesh sand belts; The proportion of the sanding amount of each sand roller in the total sanding amount is: coarse sand is 60-70%, fine sand is 20%, fine sand is <10%, and the balance is less than or equal to 5%.

6. A waterproof strengthened floor prepared by the preparation method in any one of claims 1 to 5.

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