Waterproof laminate flooring and preparation method thereof

Abstract

The invention belongs to the field of floor production, and particularly relates to a waterproof laminate floor and a preparation method. The method sequentially comprises the steps of slicing, hot grinding, drying, paving, hot pressing, plate turning and cooling, stacking and sanding. In the hot grinding process, solid paraffin is melted to obtain liquid paraffin, the temperature is controlled to be 55-65 DEG C, the liquid paraffin is directly added into a discharging screw and fed into a grinding chamber body, a grinding disc rotating at a high speed is used for dispersing the liquid paraffin into tiny liquid drops, meanwhile, an absolute ethyl alcohol pipe is connected to the outside of the grinding chamber body, and absolute ethyl alcohol is added into the grinding chamber body; uniformly mixing with the separated fibers and adhering to the surface; the liquid paraffin is dispersed into tiny liquid drops by adding absolute ethyl alcohol in the hot grinding process in cooperation with a grinding disc, the paraffin can better permeate into pores of wood fibers, stronger mechanical interlocking and chemical bonding effects are formed, finally, the paraffin forms a continuous and uniform waterproof layer on the surfaces of the wood fibers, and therefore the waterproof effect is improved.

Description

Technical Field

[0001] The invention belongs to the field of floor production, and in particular relates to a waterproof laminate floor and a preparation method thereof. Background Art

[0002] High-density board (English: High Density Board (wood)) is a kind of board, which is divided into low-density, medium-density and high-density according to density. According to the raw materials, it can be divided into fiber density board, glued density board, particle density board, etc. Among them, fiber density board is made by soaking wood, branches and other objects in water, crushing and pressing them. It is an artificial board made of wood fiber or other plant fiber as raw materials, and applying urea-formaldehyde resin or other suitable adhesives. Fiber density board has the characteristics of fine material, flat surface, smooth and beautiful appearance, and can be processed with various coatings.

[0003] Existing high-density boards generally do not have a waterproof effect and cannot be used in some wet areas, such as kitchens, bathrooms and other special areas. After searching for waterproof density fiberboards, it was found that:

[0004] CN1235728A discloses a medium density fiberboard and its production method. The medium density fiberboard is composed of mulberry branch fibers, and the mulberry branch fibers contain waterproofing agent and adhesive. The production method of the medium density fiberboard comprises: chipping mulberry branch raw materials; steaming and softening the mulberry branch slices; adding waterproofing agent to the steamed and softened mulberry branch slices; hot grinding and decomposing into fibers, adding adhesive at the fiber outlet of the hot grinding machine; drying the fibers, and then forming the fiber auxiliary assembly, pre-pressing, and sawing the edge of the slab; hot pressing the slab to finally make the medium density fiberboard.

[0005] The inventors discovered that the above technical solution, when making high-density fiberboard, is beneficial to the distribution of paraffin because it is added during hot grinding. However, since the moisture content in the fibers is still relatively high during hot grinding, it affects the combination of paraffin and fibers, resulting in the inability to achieve a continuous and uniform waterproof layer on the outside of the fibers. It also affects the uniform distribution inside the density fiberboard and affects the mechanical strength, making the final density fiberboard not waterproof. Summary of the invention

[0006] In order to solve the above technical problems, the inventors have obtained the technical solution of the present invention through practice and summary. The present invention adopts the following technical solution:

[0007] A method for preparing a waterproof laminate floor, the preparation steps are as follows:

[0008] S100 slices:

[0009] Put the plant fiber raw materials on the conveyor belt, remove the impurities such as rubber, metal, stone, etc., and transport them to the drum chipper. After being chipped by the drum chipper, wood chips are obtained and transported to the silo for storage and standby;

[0010] S200 hot grinding:

[0011] Fiber separation: The wood chips are preheated to 80-90℃ in the preheating bin, and are continuously compressed into wood plugs by the feeding screw, and then enter the cooking cylinder for softening. After the wood plugs are cooked and softened, they are sent to the hot mill by the unloading screw for fiber separation to obtain qualified fibers. The pressure of the cooking cylinder and the grinding chamber is 8-9 Bar;

[0012] First, melt the solid paraffin to get liquid paraffin, and control the temperature at 55-65℃. Then add the liquid paraffin directly into the unloading screw and send it into the grinding chamber. Use the high-speed rotating grinding disc to disperse 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 evenly mixed with the separated fibers and attached to their surface.

[0013] Gluing: The fibers are transported out of the hot mill and the fibers are sprayed with adhesive;

[0014] The amount of paraffin added is 7-9 kg / m 3 , the amount of anhydrous ethanol added is 7~10L / m 3 , the adhesive is urea-formaldehyde resin glue, the glue application amount is 220~280kg / m 3 ;

[0015] S300 Dry:

[0016] After sizing, the fiber passes through a dryer to control its moisture content within a certain range, maintaining it at 8-12%;

[0017] S400 Paving:

[0018] The dried fiber is transported to the paving machine through the feeding fan, and the fiber is roughly formed by vacuum airflow, and then the slab is formed by the sweeping roller and pre-pressing machine;

[0019] S500 heat press:

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

[0021] S600, flap cooling:

[0022] The rough board after hot pressing enters the board turning machine for cooling;

[0023] S700, stacking:

[0024] The rough boards after forming are stored in the stacking area for cooling. The rough boards are stacked in piles for 48 hours to make the moisture in the boards evenly distributed and balanced with the atmospheric humidity, and to complete the quenching and tempering treatment;

[0025] S800, Sanding:

[0026] Use a sanding machine to sand the surface of the rough board to make the surface smooth, increase the surface strength and make the thickness uniform.

[0027] A method for preparing a waterproof laminate floor, the preparation steps are as follows:

[0028] S100 slices:

[0029] Put the plant fiber raw materials on the conveyor belt, remove the impurities such as rubber, metal, stone, etc., and transport them to the drum chipper. After being chipped by the drum chipper, wood chips are obtained and transported to the silo for storage and standby;

[0030] S200 hot grinding:

[0031] Fiber separation: The wood chips are preheated to 80-90℃ in the preheating bin, and are continuously compressed into wood plugs by the feeding screw, and then enter the cooking cylinder for softening. After the wood plugs are cooked and softened, they are sent to the hot mill by the unloading screw for fiber separation to obtain qualified fibers. The pressure of the cooking cylinder and the grinding chamber is 8-9 Bar;

[0032] S300, modified

[0033] Under closed conditions, the fiber is treated once in a high-temperature and high-pressure vapor-liquid two-phase system to remove the liquid components by filtration. The temperature is 110-130°C and the pressure is 8-10 Bar.

[0034] The fiber is treated twice by microwave with a power of 3-5 kW, a frequency of 2450 MHz, and a treatment time of 1-2 s to obtain activated fiber;

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

[0036] Then, the modified fiber is placed in an ethanol aqueous solution, KH-550 is added in an amount of 5-10% of the modified fiber, and the reaction is stirred for 2-3 hours at a reaction temperature of 50-60°C, and a solid product is obtained by filtration;

[0037] S400, Gluing:

[0038] Spray the fiber with adhesive, the adhesive is urea-formaldehyde resin glue, the amount of glue applied is 220-280kg / m 3 , constant temperature reaction for 2-4h, the reaction temperature is 60-80℃;

[0039] S500 Dry:

[0040] After sizing, the fiber passes through a dryer to control its moisture content within a certain range, maintaining it at 8-12%;

[0041] S600 Paving:

[0042] The dried fiber is transported to the paving machine through the feeding fan, and the fiber is roughly formed by vacuum airflow, and then the slab is formed by the sweeping roller and pre-pressing machine;

[0043] S700 Heat Press:

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

[0045] S800, flap cooling:

[0046] The rough board after hot pressing enters the board turning machine for cooling;

[0047] S900, stacking:

[0048] The rough boards after forming are stored in the stacking area for cooling. The rough boards are stacked in piles for 48 hours to make the moisture in the boards evenly distributed and balanced with the atmospheric humidity, and to complete the quenching and tempering treatment;

[0049] S1000, Sanding:

[0050] Use a sanding machine to sand the surface of the rough board to make the surface smooth, increase the surface strength and make the thickness uniform.

[0051] Preferably, in the closed space, nitrogen is introduced into the interior to fully replace the internal air at least twice, and then a 1: (1-3) mixed gas of nitrogen and fluorine is used to replace the internal nitrogen. After reacting for 1.5-2 hours, nitrogen is introduced to fully replace the internal reacted gas.

[0052] Preferably, when the nitrogen fully replaces the internal reaction gas, the internal temperature is raised to 120-140° C. and maintained at this temperature for 0.5-1 h, and the gas replacement is always maintained during the temperature increase stage to finally obtain modified fibers.

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

[0054] After the slicing, screening is performed, and the screening process is as follows:

[0055] The flakes cut by the chipper are of different sizes and still contain various impurities. After screening by shaking screen, the large wood chips and impurities are removed to obtain suitable flakes, which are then sent to the hot grinder through the feed screw.

[0056] The specifications of the wood chips are 15-35mm in length, 15-25mm in width, 3-5mm in thickness, and the moisture content of the wood chips is 35-50%.

[0057] Preferably, the adhesive is sprayed using a protective variable-diameter glue sprayer, comprising:

[0058] A glue spray head, the glue inlet of the glue spray head is connected to the glue storage tank through an external hose;

[0059] The variable diameter protection assembly includes a micro motor fixedly mounted on the outside of the glue spray head and an adjusting ring threadedly mounted at the glue outlet of the glue spray head, and a rotating ring is mounted on the adjusting ring;

[0060] An isolation plate, the isolation plate is located on the top of the fiber, a conveyor belt for conveying the fiber is arranged below the isolation plate, a containing groove is arranged on the conveyor belt, and a ventilation port is arranged at the bottom of the containing groove;

[0061] The output end of the micro motor is provided with a cross shaft, a gear plate is mounted on the cross shaft, a bearing tray is provided on the top of the gear plate, a gear ring meshing with the gear plate is provided on the top side of the adjusting ring, and the bearing tray is supported on the top of the adjusting ring;

[0062] A plurality of deflected high-pressure air pipes are arranged circumferentially on the sides of the rotating ring and the glue spraying head. 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 projections of the plurality of high-pressure air pipes on the horizontal plane are distributed in a vortex shape.

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

[0064] Preferably, the dryer adopts 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 pipeline is 1m, the length of the drying pipeline is 75-85 meters, and the end of the pipeline 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.

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

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

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

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

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

[0072] Fine sand: polished by polishing roller;

[0073] The proportion of the sanding volume of each sand roller to the total sanding volume is: coarse sand is 60-70%, fine sand is 20%, concentrated sand is <10%, 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 and a grinding disc during hot grinding to disperse liquid paraffin into extremely small droplets, it is helpful for 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 of paraffin on the surface of wood fibers, thereby improving the waterproof effect.

[0076] 2. Another method of the present invention: Through the heat-milled fibers, high-pressure and high-temperature gas-liquid two-phase treatment is carried out to introduce a large number of hydroxyl groups on the wood surface, providing more reaction sites for subsequent microwave treatment. Traditional microwave treatment can heat the fibers and play a drying role. When applied to this scheme, it has been found through research that pressure is also generated inside the fibers, and the pressure change helps to destroy the cell structure of the wood. At the same time, microwave treatment also changes the electric field distribution and molecular motion state inside the fibers, so that functional groups such as hydroxyl groups that were originally wrapped inside the cell wall are more exposed. Subsequently, the surface of the wood fiber is treated with plasma technology, and a large number of active groups and defects can be introduced on its surface. These active groups and defects are conducive to the adsorption and reaction of subsequent fluorinating agents. Fluorinating agents are introduced on the fiber surface after plasma treatment, and carbon-fluorine bonds are formed on the wood fiber surface through chemical reactions triggered by plasma. The introduction of carbon-fluorine bonds can significantly improve the hydrophobic properties of the fibers and can significantly improve the interfacial bonding strength of the wood. This enhanced interfacial bonding helps to resist external stress and prevent wood from cracking or breaking. Then, through the reaction of KH-550 and the subsequent spraying of urea-formaldehyde resin glue, an effective combination of the two is achieved. This can make the fiber essence absolutely moisture-proof and ensure the waterproof performance of the density board.

[0077] 3. The present invention adopts a double-sided sanding process, which sequentially goes through the steps of coarse sanding, fine sanding, and fine sanding to reduce the thickness tolerance of the board, eliminate board surface defects, make the board thickness uniform, and make the surface smooth and flat, which is easy to use and carry out surface decoration.

[0078] 4. The present invention adopts a new type of glue spraying method, a protective spraying method, and utilizes high-pressure air pipes to be distributed in a vortex shape on the outside of the glue spraying path to form an airflow isolation cover, and a relatively stable air pressure field is formed inside the isolation cover. Spraying glue in its air pressure field can ensure the quality of glue spraying and high glue utilization rate and uniform spraying. When spraying, the negative pressure generator forms a vortex airflow through the high-pressure air pipe, and the air pressure field is in a negative pressure state, which can keep the fibers within the coverage range in a loose / floating state, which is conducive to the glue liquid uniformly covering the fibers; when the spraying is completed, the three-way solenoid valve is switched to the high-pressure air source and connected to the high-pressure air pipe, and at the same time, the micro-motor adjusts the position of the bottom of the high-pressure air pipe, so that the bottom coverage range becomes smaller, resulting in a change in the negative pressure direction of the air pressure field, so that the sprayed fibers fall back to their original positions. It should be noted that the fibers need to stop moving during the entire spraying process, otherwise the fibers will float, which solves the problem of direct spraying easily causing fiber deviation and false spraying.

[0079] 5. The present invention adopts a two-stage drying method:

[0080] 1) Drying in stages to improve drying efficiency

[0081] The two-stage drying system achieves a gradual reduction in the moisture content of wet fibers through two stages of drying: primary and secondary. The primary drying pipeline has a large diameter, moderate length, and a high medium temperature (150-160°C), which can quickly remove a large amount of moisture from the fiber surface. Subsequently, the secondary drying pipeline further removes moisture from the inside of the fiber at a lower medium temperature (85-100°C) and a longer path (75-85 meters), 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 to improve drying effect

[0083] The two-stage drying system can more accurately control parameters such as temperature, humidity and airflow speed during the drying process. The rapid heating of the first-stage drying helps to quickly evaporate the moisture on the fiber surface, while the low temperature and long time of the second-stage drying is conducive to the slow release of moisture inside the fiber, avoiding fiber damage or internal stress concentration caused by high-temperature rapid drying. In addition, by adjusting the airflow speed (20-30m / s), it can ensure that the wet fiber is evenly heated and cooled during the drying process, further improving the drying effect.

[0084] 3) Reduce energy consumption and improve energy utilization

[0085] The secondary drying system can choose to use the waste heat discharged from the primary drying as a preheating source, reducing the use of fresh hot air, improving energy utilization and reducing production costs.

[0086] 4) Prevent agglomeration and improve conveying and paving effects

[0087] Wet fibers are prone to agglomeration due to water evaporation during the drying process, which affects the subsequent transportation and laying effects. The two-stage drying system effectively avoids the agglomeration of fibers by precisely controlling the drying conditions and drying in stages. The rapid heating of the first-stage drying helps to break the moisture bridges between fibers, while the low temperature and long time of the second-stage drying helps to further loosen and disperse the fibers. In addition, the use of a cyclone separator can effectively separate the dry fibers from the air, further improving the looseness and uniformity of the fibers.

[0088] 5) Improve product quality

[0089] After the secondary drying process, the moisture content of wet fibers is more uniform and stable, which is conducive to the smooth progress of the subsequent hot pressing and laying processes. At the same time, due to the improvement of drying effect and the reduction of fiber agglomeration, the quality and stability of the final product are also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 A preparation method according to an embodiment;

[0091] Figure 2 A preparation method according to another embodiment;

[0092] Figure 3 This is the structural front view of the protective variable diameter glue sprayer;

[0093] Figure 4 This is the main view of the glue spray head;

[0094] Figure 5 for Figure 4 A partial enlarged view of the middle A;

[0095] Figure 6 It is a bottom view of the high pressure gas pipe;

[0096] Figure 7 A top view of the isolation plate. DETAILED DESCRIPTION

[0097] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0098] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0099] Example 1

[0100] like Figure 1 As shown, a method for preparing a waterproof laminate floor, the preparation steps are as follows:

[0101] S100 slices:

[0102] Put the plant fiber raw materials on the conveyor belt, remove the impurities such as rubber, metal, stone, etc., and transport them to the drum chipper. After being chipped by the drum chipper, wood chips are obtained and transported to the silo for storage and standby;

[0103] S200 hot grinding:

[0104] Fiber separation: The wood chips are preheated to 80-90℃ in the preheating bin, and are continuously compressed into wood plugs by the feeding screw, and then enter the cooking cylinder for softening. After the wood plugs are cooked and softened, they are sent to the hot mill by the unloading screw for fiber separation to obtain qualified fibers. The pressure of the cooking cylinder and the grinding chamber is 8-9 Bar;

[0105] First, melt the solid paraffin to get liquid paraffin, and control the temperature at 55-65℃. Then add the liquid paraffin directly into the unloading screw and send it into the grinding chamber. Use the high-speed rotating grinding disc to disperse 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 evenly mixed with the separated fibers and attached to their surface.

[0106] Gluing: The fibers are transported out of the hot mill and the fibers are sprayed with adhesive;

[0107] The amount of paraffin added is 7-9 kg / m 3 , the amount of anhydrous ethanol added is 7~10L / m 3 , the adhesive is urea-formaldehyde resin glue, the glue application amount is 220~280kg / m 3 ;

[0108] S300 Dry:

[0109] After sizing, the fiber passes through a dryer to control its moisture content within a certain range, maintaining it at 8-12%;

[0110] S400 Paving:

[0111] The dried fiber is transported to the paving machine through the feeding fan, and the fiber is roughly formed by vacuum airflow, and then the slab is formed by the sweeping roller and pre-pressing machine;

[0112] S500 heat press:

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

[0114] Hot pressing is one of the most important processes in the manufacture of floor substrates. It uses high temperature and high pressure to evaporate the moisture in the slab, solidify the adhesive, and compact the slab, causing a series of physical and chemical changes in the various components of the raw materials to form a plain board that meets quality requirements.

[0115] The temperature of the high-pressure zone and the medium-pressure zone is generally set at 220-250°C, and the temperature of the low-pressure zone is generally set at 190°C. The maximum pressure in the high-pressure zone can usually reach 5.0MPa. The pressure in the medium-pressure zone is generally 2.5-4.0MPa, and the pressure in the low-pressure zone is usually below 2.0MPa.

[0116] S600, flap cooling:

[0117] The rough board after hot pressing enters the board turning machine for cooling; the purpose of cooling: after the rough board discharged from hot pressing is cooled by the board turning machine, it can prevent the adhesive from hydrolyzing under continuous high temperature, so that the board maintains a high strength.

[0118] S700, stacking:

[0119] The rough boards after forming are stored in the stacking area for cooling. The rough boards are stacked in piles for 48 hours to make the moisture in the boards evenly distributed and balanced with the atmospheric humidity, and to complete the quenching and tempering treatment;

[0120] S800, Sanding:

[0121] Use a sanding machine to sand the surface of the rough board to make the surface smooth, increase the surface strength and make the thickness uniform.

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

[0123] It also includes vertical and horizontal trimming steps:

[0124] Cut off the uneven, loose and inferior edges of the boards according to the required specifications to make them into specified sizes.

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

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

[0127] It also includes seam cutting processing, in which a seam is cut at the edge position by a groove cutting machine. This process is also a traditional process, so it will not be further elaborated here.

[0128] Inspection: Inspect and grade the plain boards according to relevant standards for floor substrates.

[0129] Product inspection is divided into:

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

[0131] Appearance quality inspection, including: local softness, corner defects, oil stains, water spots, and stratification and bubbling.

[0132] Physical and mechanical properties testing, including: static bending strength, internal bonding strength, surface bonding strength, etc.

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

[0134] Example 2

[0135] like Figure 2 As shown, a method for preparing a waterproof laminate floor, the preparation steps are as follows:

[0136] S100 slices:

[0137] Put the plant fiber raw materials on the conveyor belt, remove the impurities such as rubber, metal, stone, etc., and transport them to the drum chipper. After being chipped by the drum chipper, wood chips are obtained and transported to the silo for storage and standby;

[0138] S200 hot grinding:

[0139] Fiber separation: The wood chips are preheated to 80-90℃ in the preheating bin, and are continuously compressed into wood plugs by the feeding screw, and then enter the cooking cylinder for softening. After the wood plugs are cooked and softened, they are sent to the hot mill by the unloading screw for fiber separation to obtain qualified fibers. The pressure of the cooking cylinder and the grinding chamber is 8-9 Bar;

[0140] S300, modified

[0141] Under closed conditions, the fiber is treated once in a high-temperature and high-pressure vapor-liquid two-phase system, and the liquid phase components are filtered to remove the fiber with a moisture content of 15-20%. The temperature is 110-130°C and the pressure is 8-10Bar.

[0142] The fiber is treated twice by microwave with a power of 3-5 kW, a frequency of 2450 MHz, and a treatment time of 1-2 s to obtain activated fiber;

[0143] Too high a power will cause the internal temperature of the material to rise sharply, causing problems such as cracking, deformation, and even coking; while too low a power will not achieve the expected processing effect.

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

[0145] In a closed space, introduce nitrogen to fully replace the internal air at least twice, then replace the internal nitrogen with a 1: (1-3) mixture of nitrogen and fluorine. After reacting for 1.5-2 hours, introduce nitrogen to fully replace the internal reacted gas. The ratio used by our company is 1:2.5;

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

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

[0148] S400, Gluing:

[0149] Spray the fiber with adhesive, the adhesive is urea-formaldehyde resin glue, the amount of glue applied is 220-280kg / m 3 , react at a constant temperature for 2-4 hours, the reaction temperature is 60-80°C, preferably 70°C.

[0150] S500 Dry:

[0151] After sizing, the fiber passes through a dryer to control its moisture content within a certain range, maintaining it at 8-12%;

[0152] S600 Paving:

[0153] The dried fiber is transported to the paving machine through the feeding fan, and the fiber is roughly formed by vacuum airflow, and then the slab is formed by the sweeping roller and pre-pressing machine;

[0154] S700 Heat Press:

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

[0156] S800, flap cooling:

[0157] The rough board after hot pressing enters the board turning machine for cooling;

[0158] S900, stacking:

[0159] The rough boards after forming are stored in the stacking area for cooling. The rough boards are stacked in piles for 48 hours to make the moisture in the boards evenly distributed and balanced with the atmospheric humidity, and to complete the quenching and tempering treatment;

[0160] S1000, Sanding:

[0161] Use a sanding machine to sand the surface of the rough board to make the surface smooth, increase the surface strength and make the thickness uniform.

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

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

[0164] It also includes vertical and horizontal trimming steps:

[0165] Cut off the uneven, loose and inferior edges of the boards according to the required specifications to make them into specified sizes.

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

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

[0168] It also includes seam cutting processing, in which a seam is cut at the edge position by a groove cutting machine. This process is also a traditional process, so it will not be further elaborated here.

[0169] Inspection: Inspect and grade the plain boards according to relevant standards for floor substrates.

[0170] Product inspection is divided into:

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

[0172] Appearance quality inspection, including: local softness, corner defects, oil stains, water spots, and stratification and bubbling.

[0173] Physical and mechanical properties testing, including: static bending strength, internal bonding strength, surface bonding strength, etc.

[0174] Other indicators include density, moisture content, 24h 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 residues, and non-wood plant fiber raw materials;

[0177] After the slicing, screening is performed, and the screening process is as follows:

[0178] The chips cut by the chipper are of different sizes and still contain various impurities. After screening by shaking screen, the large wood chips and impurities are removed to obtain suitable chips, which are then sent to the hot grinder through the feeding screw.

[0179] The specifications of the wood chips are 15-35mm in length, 15-25mm in width, 3-5mm in thickness, and the moisture content of the wood chips is 35-50%.

[0180] Example 4

[0181] Wherein, the dryer adopts a two-stage drying system;

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

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

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

[0185] For the first-level drying duct, when the diameter is less than 2m, the reduced diameter will cause the airflow channel to become narrower, thereby increasing the resistance of the airflow in the duct, which will not only increase the energy consumption of the fan, but also affect the uniformity and stability of the airflow, thereby affecting the drying effect. Due to the increase in airflow resistance, the airflow speed may slow down, resulting in a decrease in the contact time between the fiber and the hot air, thus affecting the evaporation rate of water and the drying efficiency.

[0186] When the diameter is higher than 2m, the increase in diameter means that more hot air is needed to fill the pipe, thereby increasing energy consumption. A larger pipe area also means more heat loss, further reducing energy efficiency. The increase in diameter will directly lead to an increase in pipe material and manufacturing costs, and will also increase the difficulty and cost of installation and maintenance. Although the increase in diameter can provide a larger airflow channel, it also causes uneven distribution of airflow in the pipe, affecting the uniformity of the drying effect.

[0187] When the length is too long, the long pipe will increase the residence time of the fiber in the pipe, thereby prolonging the drying process, which is prone to fiber damage or internal stress concentration. It will lead to a decrease in production line speed and production capacity. The long drying process will consume more hot air and energy, increasing production costs. Too long pipes will take up more production space, increasing the floor space and investment cost of the equipment.

[0188] When the length is too short, the short pipe may not provide enough drying time, resulting in the fiber moisture content failing to meet the requirements before hot pressing. In order to complete the drying process in a short time, the air flow speed needs to be increased. Too high an air flow speed will cause problems such as uneven distribution of fibers in the pipe or static electricity.

[0189] When the medium temperature is lower than 150-160℃, the medium temperature is too low, which will reduce the heat transfer efficiency of the hot air, thereby extending the drying time and reducing the drying efficiency. In order to compensate for the problem of reduced drying efficiency caused by insufficient temperature, it is necessary to increase the flow rate of hot air or increase the heating temperature, thereby increasing energy consumption. Too low a temperature will prevent the moisture inside the fiber from completely evaporating, affecting the quality and stability of the product.

[0190] When the medium temperature is higher than 150-160℃, the excessively high temperature may cause chemical reactions such as pyrolysis and oxidation on the fiber surface, resulting in fiber damage and performance degradation. Although high temperature can improve drying efficiency, it will also increase the energy consumption and operating costs of the heating equipment. At the same time, it is easy to cause the risk of premature curing of the adhesive.

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

[0192] Example 5

[0193] Among them, the sanding equipment is a double-sided wide-band sanding machine;

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

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

[0196] Fine sand: polished by polishing roller;

[0197] The proportion of the sanding volume of each sand roller to the total sanding volume is: coarse sand is 60-70%, fine sand is 20%, concentrated sand is <10%, and the remainder is less than or equal to 5%.

[0198] Example 6

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

[0200] The glue spray head 1 has a glue inlet externally connected to a hose connected to a glue storage tank;

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

[0202] Isolation plate 5, which is located at the top of the conveying fiber, is provided with a through slot for spraying glue on the isolation plate 5, the fiber thickness is 4-8mm, preferably 5mm, a conveyor belt for conveying fibers is provided below the isolation plate 5, a containing slot is provided on the conveyor belt, and a ventilation port is provided at the bottom of the containing slot, the isolation plate 5 and the conveyor belt may be in contact, or a certain gap may be left, and the gap is generally selected to be 1-2mm, and the containing slot is used to cooperate with the through slot to spray glue on the fibers in the slot;

[0203] The output end of the micro motor 2 is provided with a cross shaft 21, a gear plate 22 is mounted on the cross shaft 21, a bearing tray 23 is provided on the top of the gear plate 22, a gear ring 31 meshing with the gear plate 22 is provided on the top side of the adjusting ring 3, and the bearing tray 23 is supported on the top of the adjusting ring 3;

[0204] A plurality of deflected high-pressure air pipes 8 are circumferentially arranged on the sides of the rotating ring 4 and the glue spray head 1. The high-pressure air pipes 8 are externally connected to a high-pressure air source 6 and a negative pressure generator 7 through a three-way solenoid valve. The projections of the plurality of high-pressure air pipes 8 on the horizontal plane are distributed in a vortex shape.

[0205] A connecting short rod 7 is rotatably mounted on the side of the rotating ring 4, and one end of the connecting short 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 adjustment sleeve 3 and the glue outlet at the bottom of the glue spray head 1, thereby achieving outward extension or inward retraction, and achieving adjustment of the coverage area.

[0206] A new glue spraying method is adopted, and a high-pressure air pipe 8 is distributed in a vortex shape on the outside of the glue spraying path to form an airflow isolation cover, and a relatively stable air pressure field is formed inside the isolation cover. Spraying glue in the air pressure field can ensure the quality of glue spraying, ensure high utilization rate of glue liquid and uniform spraying. When spraying, the air inlet of the high-pressure air pipe is distributed in the form of outward diffusion, and the negative pressure generator forms a vortex airflow through the high-pressure air pipe. The air pressure field is in an upward negative pressure state, which can keep the fibers within the coverage range loose / floating (high looseness approaches floating) state, and the glue liquid is in a uniform and diffuse state in the air pressure field. Scattered state, while traditional spraying cannot achieve uniform coverage, which is conducive to the glue to evenly cover the fiber; when the spraying is completed, the three-way solenoid valve switches to the high-pressure air source and connects with the high-pressure air pipe. At the same time, the micro motor adjusts the position of the bottom of the high-pressure air pipe, so that the bottom coverage range becomes smaller, resulting in a change in the negative pressure direction of the air pressure field. The air pressure field is in a downward negative pressure state, so that the sprayed fiber falls back to its original position. It should be noted that the fiber needs to stop moving during the entire spraying process, otherwise the fiber will float and scatter, which solves the problem of false spraying caused by direct spraying in the past.

[0207] Waterproof performance and durability test:

[0208] Waterproof performance and durability test:

[0209] 1. Simulate real life scenarios:

[0210] Four pieces of flooring are spliced ​​together, and a 500*300 bottomless transparent box frame is placed on the upper surface of the splicing position of the four pieces of flooring, and water is sealed around it. Normal temperature water of 20±5℃ and a water depth of 50±5mm are injected into the box frame. It is left for 72±1h, and after draining the water and wiping it until the surface is dry, observe whether there is expansion or bulging at the edge of the splicing. It is observed that the comparative example has bulging / expansion phenomenon relative to the embodiment.

[0211] 2. Experimental standard testing

[0212] According to method 2 of 4.5 Water absorption thickness expansion rate in GB / T17657-2013, the floors obtained in Examples 1 to 3 have a groove water absorption thickness expansion rate of ≤4%, which is significantly better than the ≤8% required by the GB / T18102-2021 standard. Under the same method, the groove water absorption thickness expansion rate of the control example is ≤8%.

[0213] Based on the above situation, the water absorption thickness expansion rate is an important evaluation basis for the waterproofness of laminate flooring. The highest index requirement of China's laminate flooring product national standard "GB / T18102-2021" is ≤8%, which is basically the same as the requirements of the European laminate flooring product standard "EN 13329:2016+A2:2021". Method 2 in 4.5 Water absorption thickness expansion rate in "GB / T17657-2013" is also basically the same as "ES ISO 24336:2005".

[0214] Therefore, the waterproof performance of the waterproof laminate floor obtained in the above embodiment is obviously better than the Chinese national standard and European standard of laminate floor.

[0215] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. The replacement may be a replacement of a part of the structure, device, method step, or a complete technical solution. Any equivalent replacement or change according to the technical solution and the inventive concept of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A method for preparing a waterproof laminate floor, the steps comprising slicing, hot grinding, drying, paving, hot pressing, panel cooling, stacking, and sanding; It is characterized in that The hot grinding steps are as follows: Fiber separation: The wood chips are preheated to 80-90℃ in the preheating bin, and are continuously compressed into wood plugs by the feeding screw, and then enter the cooking cylinder for softening. After the wood plugs are cooked and softened, they are sent to the hot mill by the unloading screw for fiber separation to obtain qualified fibers. The pressure of the cooking cylinder and the grinding chamber is 8-9 Bar; First, melt the solid paraffin to get the liquid paraffin, and control the temperature at 55-65℃. Then add the liquid paraffin directly into the unloading screw and send it into the grinding chamber. Then, use the high-speed rotating grinding disc to disperse it into very 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, and the anhydrous ethanol is evenly mixed with the separated fibers and attached to their surface. Gluing: The fibers are transported out of the hot mill and the fibers are sprayed with adhesive; The amount of paraffin added is 7-9 kg / m 3 , the amount of anhydrous ethanol added is 7~10L / m 3 , the adhesive is urea-formaldehyde resin glue, the glue application amount is 220~280kg / m 3 .

2. A method for preparing a waterproof laminate floor, the steps of which sequentially include slicing, hot grinding, drying, paving, hot pressing, panel cooling, stacking, and sanding; characterized in that: It also includes modification and sizing steps between hot grinding and drying; The modification steps are as follows: Under closed conditions, the fiber is treated once in a high-temperature and high-pressure vapor-liquid two-phase system to remove the liquid components by filtration. The temperature is 110-130°C and the pressure is 8-10 Bar. The fiber is treated twice by microwave with a power of 3-5 kW, a frequency of 2450 MHz and a treatment time of 1-2 s to obtain activated fiber; The activated fibers are spread evenly to a thickness of 3 to 5 mm, and are subjected to plasma modification treatment in a closed space in a nitrogen and fluorine atmosphere to obtain modified fibers; Then, the modified fiber is placed in an ethanol aqueous solution, KH-550 is added in an amount of 5-10% of the modified fiber, and the reaction is stirred for 2-3 hours at a reaction temperature of 50-60° C., and a solid product is obtained by filtering; The sizing steps are as follows: Spray the fiber with adhesive, the adhesive is urea-formaldehyde resin glue, the amount of glue applied is 220-280kg / m 3 , react at constant temperature for 2 to 4 hours, the reaction temperature is 60 to 80°C.

3. The method for preparing a waterproof laminate floor according to claim 2, characterized in that: In the closed space, nitrogen is introduced to fully replace the internal air at least twice, and then a 1: (1-3) mixed gas of nitrogen and fluorine is used to replace the internal nitrogen. After reacting for 1.5-2 hours, nitrogen is introduced to fully replace the internal reacted gas.

4. The method for preparing a waterproof laminate floor according to claim 3, characterized in that: When the nitrogen 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 the gas replacement is always maintained during the temperature increase stage to finally obtain modified fibers.

5. The method for preparing a waterproof laminate floor according to claim 1 or 2, characterized in that: The plant fiber raw materials include pine, poplar, miscellaneous wood, small-diameter logs, branches, logging residues, and non-wood plant fiber raw materials; After the slicing, screening is performed, and the screening process is as follows: The chips cut by the chipper are of different sizes and still contain various impurities. After screening by shaking screen, the large wood chips and impurities are removed to obtain suitable chips, which are then sent to the hot grinder through the feeding screw. The specifications of the wood chips are 15-35mm in length, 15-25mm in width, 3-5mm in thickness, and the moisture content of the wood chips is 35-50%.

6. The method for preparing a waterproof laminate floor according to claim 1, characterized in that: The adhesive spraying adopts a protective variable diameter glue sprayer, including: A glue spray head, the glue inlet of the glue spray head is connected to the glue storage tank through an external hose; The variable diameter protection assembly includes a micro motor fixedly mounted on the outside of the glue spray head and an adjusting ring threadedly mounted at the glue outlet of the glue spray head, and a rotating ring is mounted on the adjusting ring; An isolation plate, the isolation plate is located on the top of the fiber, a conveyor belt for conveying the fiber is arranged below the isolation plate, a containing groove is arranged on the conveyor belt, and a ventilation port is arranged at the bottom of the containing groove; Among them, a cross shaft is installed at the output end of the micro motor, a gear plate is mounted on the cross shaft, a bearing tray is arranged on the top of the gear plate, a gear ring meshing with the gear plate is arranged on the top side of the adjusting ring, and the bearing tray is supported on the top of the adjusting ring; A plurality of deflected high-pressure air pipes are arranged circumferentially on the sides of the rotating ring and the glue spraying head. 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 projections of the plurality of high-pressure air pipes on the horizontal plane are distributed in a vortex shape.

7. The method for preparing a waterproof laminate floor according to claim 6, characterized in that: A connecting short rod is rotatably mounted on the side of the rotating ring, and one end of the connecting short rod is rotatably mounted on the high-pressure air pipe.

8. The method for preparing a waterproof laminate floor according to claim 1 or 2, characterized in that: The dryer adopts a two-stage drying system; 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℃; The diameter of the secondary drying pipeline is 1m, the length of the drying pipeline is 75-85m, the end of the pipeline is connected to the cyclone separator to separate the dry fiber from the air, and the temperature of the secondary drying medium is 85-100 degrees; The entire drying time is 4 to 5 seconds, and the air flow speed is 20 to 30 m / s.

9. The method for preparing a waterproof laminate floor according to claim 1 or 2, characterized in that: The double-sided sanding allowance of the rough board is 0.5 to 1.2 mm; The sanding equipment selected is a double-sided wide belt sander; Coarse sand: Use 30-50 mesh sand belt for sand rollers 1 and 2, 60-100 mesh sand belt for sand rollers 3 and 4, and 100-120 mesh sand belt for sand rollers 5 and 6; Fine sand: Use 120-180 mesh sand belts for sand rollers 7 and 8, and 180-220 mesh sand belts for sand rollers 9 and 10; Fine sand: polished by polishing roller; The proportion of the sanding volume of each sand roller to the total sanding volume is: coarse sand is 60-70%, fine sand is 20%, refined sand is <10%, and the remainder is less than or equal to 5%.

10. A waterproof laminate floor, prepared by the preparation method according to any one of claims 1 to 9.

Images