Corrosion-resistant mildew-proof wood-plastic floor and processing method thereof

Abstract

The invention discloses a corrosion-resistant and mildew-proof wood-plastic floor and a processing method thereof, and relates to the technical field of wood-plastic floors, the processing method comprises the following steps: carrying out refined pretreatment on wood powder to obtain fine wood powder meeting the requirements of particle size and dryness; the method comprises the following steps: pretreating a plastic base material through recycled polyethylene plastic particles, removing impurities and adjusting the particle size of the particles; an epoxy functional mildew preventive is synthesized in situ and is used for forming covalent bonding with a wood-plastic matrix subsequently; mixing the pretreated plastic base material, the wood flour and the epoxy functional mildew preventive in sequence to obtain a uniform material; bonding and plasticizing of the materials are achieved through a reactive extrusion process, and a molten profile is formed; carrying out on-line shaping and gradient cooling on a molten profile obtained by reactive extrusion, eliminating internal stress, and carrying out curing molding; and fixed-length cutting and finish machining are conducted on the sectional material subjected to gradient cooling and curing, and the finished corrosion-resistant and mildew-proof wood-plastic floor is obtained.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wood-plastic floor, in particular relates to a kind of rot-resistant mildew-proof wood-plastic floor and processing method thereof. BACKGROUND

[0002] In the technical field of wood-plastic floor, the traditional product generally exists the technical bottleneck of insufficient corrosion resistance and mildew resistance; Because wood-plastic composite material contains natural wood fiber component, when being used in long-term humid environment or high humidity condition, it is easily eroded by mold, rot fungus and other microorganisms, leading to biological degradation of material, not only affecting the appearance, but also causing mechanical property decline and service life significantly shorten. In the prior art, physical blending method is usually used to add mildew-proof agent, however, such simple blending process makes the mildew-proof agent and the matrix material only combined by van der waals force, the interface bonding force is weak, the mildew-proof agent is easy to migrate and lose from the matrix during use, so that the mildew-proof effect is difficult to maintain, therefore we propose a kind of rot-resistant mildew-proof wood-plastic floor and processing method thereof. SUMMARY

[0003] To solve the above technical problems, the present application is realized by the following technical scheme:

[0004] The present application is a kind of rot-resistant mildew-proof wood-plastic floor and processing method thereof, comprising the following steps:

[0005] Step S1: finely pretreating wood powder to obtain fine wood powder meeting particle size and dryness requirements;

[0006] Step S2: pretreating plastic base material by recycled polyethylene plastic particles to remove impurities and adjust particle size;

[0007] Step S3: in-situ synthesis of epoxy functionalized mildew-proof agent for subsequent covalent bonding with wood-plastic matrix;

[0008] Step S4: mixing pretreated plastic base material, wood powder and epoxy functionalized mildew-proof agent in sequence to obtain uniform material;

[0009] Step S5: realizing bonding and plasticization of material by reactive extrusion process to form melt profile;

[0010] Step S6: online sizing and gradient cooling of melt profile obtained by reactive extrusion to eliminate internal stress and solidify;

[0011] Step S7: length cutting and finishing of profile after gradient cooling and solidification to obtain finished rot-resistant mildew-proof wood-plastic floor.

[0012] Further, the step S1 comprises the following steps:

[0013] Step S11, wood waste from pine or fir is put into a coarse crusher for initial crushing, and the size of the crushed material is not greater than 10 mm;

[0014] Step S12, the wood crushed material is sent into a fine grinder for grinding, and the fine wood powder passing through a 100 mesh standard sieve is collected by an air flow sorting system;

[0015] Step S13, the fine wood powder is evenly spread on a tray, the spreading thickness is not more than 5 cm, and then it is transferred to a forced air drying box;

[0016] Step S14, start the forced air drying box, and raise the temperature from room temperature to 105℃ at a rate of 10℃ per hour, keep drying at this temperature for 4 hours, and start the built-in turning device every 1 hour during the drying process to turn the wood powder;

[0017] Step S15, after the drying is completed, the wood powder is transferred to a sealed cooling tank, dry nitrogen is filled to cool it to below 35℃, and then the wood powder is input into a sealed storage bin with desiccant for standby.

[0018] Further, the step S2 includes the following steps:

[0019] Step S21, recycled high-density polyethylene plastic particles with a melt index of 0.8-1.0 g / 10 min are selected;

[0020] Step S22, the high-density polyethylene particles are put into a vortex cleaning machine, deionized water at 60℃ is used, and 1% of non-ionic surfactant is added, and the cleaning time is 15 minutes to remove surface grease and dirt;

[0021] Step S23, after the high-density polyethylene particles after cleaning are dehydrated by a centrifugal dehydrator, they are sent into a fluidized bed dryer for dynamic drying in 80℃ hot air for 2 hours;

[0022] Step S24, the dried high-density polyethylene particles are sent into a temperature-controlled crusher, the crushing cavity is kept at 15℃ by circulating water cooling, and the plastic is crushed into irregular particles with a particle size distribution of 80-120 mesh.

[0023] Further, the step S3 includes the following steps:

[0024] Step S31, a measured amount of epoxy silane (3-glycidyl ether oxypropyl trimethoxysilane) is added to a reaction kettle equipped with an anchor type stirrer and a condensation reflux device;

[0025] Step S32, start the stirring device, control the rotating speed to be 150 rpm, and slowly and uniformly add a measured amount of iodopropargyl carbamate mildew inhibitor through a constant pressure dropping funnel, and the dropping time lasts for 20 minutes;

[0026] Step S33, after the dropwise addition is completed, the jacket temperature of the reaction kettle is raised to 60℃, and the stirring speed is increased to 300 rpm. The reaction is continued under this condition for 40-50 minutes;

[0027] Step S34, after the reaction is completed, the heating is stopped, the stirring is maintained, the reaction product is discharged through the bottom valve of the reaction kettle, and the product is transferred to a nitrogen-filled storage tank for temporary storage.

[0028] Further, the step S4 includes the following steps:

[0029] Step S41, start the high-speed thermal mixer, and sequentially add 30 parts of pretreated high-density polyethylene plastic particles, 2 parts of zinc stearate lubricant, and 1 part of 1010 type antioxidant according to weight;

[0030] Step S42, mix at a speed of 800 rpm for 3 minutes to preliminarily bond the plastic components with low melt viscosity and the additives;

[0031] Step S43, under the condition of continuous stirring, slowly add 60 parts of pretreated wood powder through the side feeding port. After the wood powder is completely added, the speed is increased to 1200 rpm, and mixed for 4-7 minutes to make the wood powder be fully wrapped by the plastic-additive mixture;

[0032] Step S44, 5 parts of epoxy functionalized mildewcide are sprayed into the mixer in the form of atomization through a precision liquid feeding pump. The speed is reduced to 600 rpm, and the mixing is continued for 5-8 minutes until the overall color of the material is uniform and no visible clusters are observed.

[0033] Further, the step S5 includes the following steps:

[0034] Step S51, the uniformly mixed material is fed into the forced feeder, and is stably fed into the co-rotating twin-screw extruder from the forced feeder. The screw configuration of the twin-screw extruder is arranged in sequence from the feeding section to the die head as a conveying section, a kneading block group for high-strength shearing and mixing, a reverse thread element for establishing back pressure and prolonging residence time, and a homogenizing section;

[0035] Step S52, set the temperature of each zone of the extruder: zone 1 (feeding zone) 120℃, zone 2 (compression zone) 140℃, zone 3 (metering zone) 160℃, zone 4 (reaction zone) 170℃, and the die head temperature is 180℃;

[0036] Step S53, control the screw speed to be 200 rpm, so that the total residence time of the material in the extruder is about 2 minutes. When the melt of the material flows through the reaction zone at 170℃, the epoxy groups in the epoxy functionalized mildewcide react with the hydroxyl groups on the surface of the wood powder particles and the high-density polyethylene molecular chain under the action of shearing and heat to realize covalent bonding.

[0037] Furthermore, step S6 includes the following steps:

[0038] Step S61: Immediately feed the molten profile that has been reactively bonded from the extruder head into a vacuum shaping mold that matches the cross-sectional shape of the floor.

[0039] Step S62: Start the vacuum pump to maintain a vacuum of -0.07MPa inside the vacuum forming mold, so that the profile surface is tightly adsorbed to the cooling wall of the forming mold. At the same time, start the cooling water circulation system of the forming mold and control the cooling water temperature to 12℃.

[0040] Step S63: After initial vacuum shaping, the profile is sent into the first-stage cooling water tank, the water temperature of the tank is controlled at 20°C, and cooled for 1 minute to complete the rapid curing of the profile surface.

[0041] Step S64: Send the surface-cured profile into the second-stage cooling water tank, control the water temperature in the tank to 15°C, and cool for 2 minutes to reduce the core temperature of the profile to below 40°C and eliminate internal stress.

[0042] Furthermore, step S7 includes the following steps:

[0043] Step S71: Using a tracked traction machine, the cooled profile is pulled out of the cooling water tank at a constant rate synchronized with the extrusion speed;

[0044] Step S72: The pulled-out profile is fed into the worktable of the automatic cutting machine. The measuring roller of the cutting machine monitors the length of the profile in real time. When the length reaches the preset 2000mm, the servo motor drives the alloy saw blade to complete the transverse cutting.

[0045] Step S73: The cut single floorboard is conveyed to the double-end milling machine, and the two ends of the board are milled simultaneously by the forming milling cutter on the machine to process the connection structure.

[0046] Step S74: Feed the processed board material with the connection structure into an automatic polishing machine equipped with 800-grit sandpaper to brush the floor surface and remove micro-burrs.

[0047] The present invention has the following beneficial effects:

[0048] 1. This invention synthesizes an epoxy-functionalized antifungal agent in situ. During reactive extrusion, the agent undergoes a ring-opening reaction with the hydroxyl groups on the surface of wood flour and the molecular chains of high-density polyethylene to form covalent bonds. This firmly anchors the antifungal agent in the wood-plastic composite matrix, avoiding the problem of easy migration and loss of the antifungal agent due to weak van der Waals forces in traditional physical blending methods. This allows the antifungal agent to continue to function during long-term use, improving the antifungal durability and corrosion resistance of wood-plastic composite flooring, extending its service life. Even in humid or high-humidity environments, it can effectively inhibit the erosion of mold and decay fungi, ensuring the long-term stability and reliability of the product.

[0049] 2. The processing method of this invention includes refined pretreatment of wood flour and plastic base material, ensuring the uniformity and purity of the raw materials, providing a good foundation for subsequent bonding reactions; through reactive extrusion process, covalent bonding of the antifungal agent and the matrix is ​​achieved under precisely controlled temperature and shear force, while the gradient cooling process effectively eliminates the internal stress of the profile, avoiding product deformation and cracking, thereby improving the dimensional stability and mechanical strength of wood-plastic flooring, enabling the flooring to maintain excellent performance in long-term use, and overcoming the problem of decreased mechanical properties caused by internal stress in traditional products.

[0050] 3. The precision machining steps of this invention, such as fixed-length cutting, double-end milling of the connection structure, and surface polishing, ensure accurate floor dimensions, reliable connections, and a smooth, burr-free surface, improving the product's appearance quality and ease of installation. Simultaneously, due to the long-lasting effect of the anti-mildew agent and the stable bonding of the polymer chains, the flooring exhibits excellent weather resistance and resistance to biodegradation, maintaining long-term mechanical properties and aesthetics under various environmental conditions, thus meeting the demands of modern architecture for high-performance wood-plastic composite flooring.

[0051] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0052] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a schematic flowchart illustrating the corrosion-resistant and mildew-resistant wood-plastic flooring and its processing method according to the present invention. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Please see Figure 1 As shown, the present invention relates to a corrosion-resistant and mildew-resistant wood-plastic flooring and its processing method, comprising the following steps:

[0056] Step S1: The wood flour is pre-treated to obtain fine wood flour that meets the requirements for particle size and dryness;

[0057] Step S2: The plastic base material is pretreated using recycled polyethylene plastic granules to remove impurities and adjust the particle size.

[0058] Step S3: In-situ synthesis of epoxy functionalized antifungal agent, used to form covalent bonds with wood-plastic matrix in the subsequent process;

[0059] Step S4: Mix the pretreated plastic base material, wood powder and epoxy functionalized mildew inhibitor in sequence to obtain a homogeneous material;

[0060] Step S5: Bonding and plasticizing of materials are achieved through reactive extrusion process to form molten profiles;

[0061] Step S6: The molten profile obtained from reactive extrusion is subjected to online shaping and gradient cooling to eliminate internal stress and solidify into shape;

[0062] Step S7: Cut and finish the profile after gradient cooling and curing to a fixed length to obtain the finished corrosion-resistant and mildew-resistant wood-plastic flooring.

[0063] Step S1 includes the following steps:

[0064] Step S11: Put the wood waste from pine or fir into a coarse crusher for preliminary crushing to obtain fragments with a size no larger than 10mm;

[0065] Step S12: Feed the wood chips into a fine grinding mill for grinding, and collect the fine wood powder that can pass through a 100-mesh standard sieve through an airflow separation system;

[0066] Step S13: Spread the fine wood powder evenly on the tray, with a thickness not exceeding 5cm, and then transfer it to the forced-air drying oven;

[0067] Step S14: Start the forced-air drying oven and heat it from room temperature to 105°C at a rate of 10°C per hour. Maintain this temperature for 4 hours. During the drying process, activate the built-in turning device to turn the wood powder once every 1 hour.

[0068] Step S15: After drying, transfer the wood powder to a sealed cooling tank, fill it with dry nitrogen and cool it to below 35°C, then transfer the wood powder to a sealed storage silo containing desiccant for later use.

[0069] Step S2 includes the following steps:

[0070] Step S21: Select recycled high-density polyethylene plastic granules with a melt index of 0.8-1.0 g / 10 min;

[0071] Step S22: Put high-density polyethylene granules into a vortex cleaner, use 60°C deionized water and add 1% nonionic surfactant, and clean for 15 minutes to remove surface grease and dirt.

[0072] Step S23: After the cleaned high-density polyethylene particles are dehydrated by a centrifugal dewatering machine, they are sent to a fluidized bed dryer and dynamically dried in hot air at 80°C for 2 hours.

[0073] Step S24: The dried high-density polyethylene granules are fed into a temperature-controlled crusher. The crushing chamber is kept at 15°C by circulating water cooling, and the plastic is crushed into irregular granules with a particle size distribution between 80-120 mesh.

[0074] Step S3 includes the following steps:

[0075] Step S31: Add metered epoxy silane (3-glycidyl etheroxypropyltrimethoxysilane) to a reactor equipped with an anchor stirrer and a reflux condenser.

[0076] Step S32: Start the stirring device and control the speed to 150 rpm. At the same time, slowly and evenly add the metered iodopropynyl carbamate antifungal agent through a constant pressure dropping funnel for 20 minutes.

[0077] Step S33: After the addition is complete, raise the temperature of the reactor jacket to 60°C and increase the stirring speed to 300 rpm. Continue the reaction under these conditions for 40-50 minutes.

[0078] Step S34: After the reaction is complete, stop heating, keep stirring, discharge the reaction product through the bottom valve of the reactor, and transfer the product to a light-proof, nitrogen-filled storage tank for temporary storage.

[0079] Step S4 includes the following steps:

[0080] Step S41: Start the high-speed hot mixer and add 30 parts by weight of pretreated high-density polyethylene plastic granules, 2 parts of zinc stearate lubricant and 1 part of type 1010 antioxidant in sequence.

[0081] Step S42: Mix at 800 rpm for 3 minutes to allow the plastic component with lower melt viscosity to initially bond with the additives;

[0082] Step S43: While continuously stirring, slowly add 60 parts of pretreated wood powder through the side feed port. After all the wood powder has been added, increase the speed to 1200 rpm and mix for 4-7 minutes to ensure that the wood powder is fully coated by the plastic-additive mixture.

[0083] Step S44: Using a precision liquid feed pump, spray 5 parts of epoxy functionalized antifungal agent into the mixer in atomized form, reduce the speed to 600 rpm, and continue mixing for 5-8 minutes until the material has a uniform color and no visible clumps.

[0084] Step S5 includes the following steps:

[0085] Step S51: The uniformly mixed material is fed into the forced feeder and stably fed into the co-rotating twin-screw extruder by the forced feeder; the screw configuration of the twin-screw extruder is arranged from the feeding section to the die head as follows: conveying section, kneading block group for high-intensity shearing and mixing, reverse screw element for establishing back pressure and extending residence time, and homogenization section.

[0086] Step S52: Set the temperature of each zone of the extruder: Zone 1 (feeding zone) 120℃, Zone 2 (compression zone) 140℃, Zone 3 (metering zone) 160℃, Zone 4 (reaction zone) 170℃, and the die head temperature 180℃.

[0087] Step S53: Control the screw speed to 200 rpm so that the total residence time of the material in the extruder is about 2 minutes; when the material melt flows through the reaction zone at 170°C, under the action of shear and heat, the epoxy groups in the epoxy functionalized mildew inhibitor undergo a ring-opening reaction with the hydroxyl groups on the surface of the wood flour particles and the molecular chains of high-density polyethylene, thus achieving covalent bonding.

[0088] Step S6 includes the following steps:

[0089] Step S61: Immediately feed the molten profile that has been reactively bonded from the extruder head into a vacuum shaping mold that matches the cross-sectional shape of the floor.

[0090] Step S62: Start the vacuum pump to maintain a vacuum of -0.07MPa inside the vacuum forming mold, so that the profile surface is tightly adsorbed to the cooling wall of the forming mold. At the same time, start the cooling water circulation system of the forming mold and control the cooling water temperature to 12℃.

[0091] Step S63: After initial vacuum shaping, the profile is sent into the first-stage cooling water tank, the water temperature of the tank is controlled at 20°C, and cooled for 1 minute to complete the rapid curing of the profile surface.

[0092] Step S64: Send the surface-cured profile into the second-stage cooling water tank, control the water temperature in the tank to 15°C, and cool for 2 minutes to reduce the core temperature of the profile to below 40°C and eliminate internal stress.

[0093] Step S7 includes the following steps:

[0094] Step S71: Using a tracked traction machine, the cooled profile is pulled out of the cooling water tank at a constant rate synchronized with the extrusion speed;

[0095] Step S72: The pulled-out profile is fed into the worktable of the automatic cutting machine. The measuring roller of the cutting machine monitors the length of the profile in real time. When the length reaches the preset 2000mm, the servo motor drives the alloy saw blade to complete the transverse cutting.

[0096] Step S73: The cut single floorboard is conveyed to the double-end milling machine, and the two ends of the board are milled simultaneously by the forming milling cutter on the machine to process the connection structure.

[0097] Step S74: Feed the processed board material with the connection structure into an automatic polishing machine equipped with 800-grit sandpaper to brush the floor surface and remove micro-burrs.

[0098] One specific application of this embodiment is:

[0099] Implementation Background:

[0100] This embodiment is applied to a production line of a building materials company with an annual output of 500 tons of corrosion-resistant and mildew-resistant wood-plastic flooring. Designed for use in humid environments (such as underground garages and outdoor terraces), it utilizes the patented process to produce the product. The core raw materials and specifications used are as follows:

[0101] Wood waste: Selected pine scraps from furniture factories, with an initial moisture content of 18%;

[0102] Plastic base material: recycled high-density polyethylene (HDPE) granules, melt flow index test value of 0.9 g / 10 min (230℃, 2.16 kg load);

[0103] Ingredients for the antifungal agent: epoxy silane (3-glycidyl etheroxypropyltrimethoxysilane, purity 98%), iodopropynyl carbamate (IPBC, content 99%);

[0104] Additives: Zinc stearate (industrial grade, particle size 5μm), 1010 type antioxidant (hindered phenol, purity 99%).

[0105] Implementation steps:

[0106] Step 1:

[0107] 1. Preliminary crushing: Pine waste is fed into the XCJ600 coarse crusher, the screen mesh size is adjusted to 10mm, and the crushed material is obtained with a maximum size of 9.5mm. The hourly processing capacity is controlled at 80kg.

[0108] 2. Fine grinding and sorting: The crushed material is fed into the JM800 fine grinding mill, the grinding gap is set to 0.1mm, and a QLF100 airflow sorting system is used to collect the fine wood powder that passes through a 100-mesh standard sieve. The undersize yield is 92%.

[0109] 3. Spreading and drying: Spread the fine wood powder evenly on a stainless steel tray to a thickness of 3cm, and transfer it to a GZX400 type forced-air drying oven; heat from 25℃ to 105℃ at a rate of 10℃ / h, and keep it at that temperature for 4 hours. During this period, start the built-in flipping device once every 1 hour to ensure uniform drying.

[0110] 4. Cooling and storage: After drying, when the moisture content of the wood flour drops to 2.1%, it is immediately transferred to an MN500 type sealed cooling tank, filled with 99.9% pure dry nitrogen, and cooled to 32°C within 30 minutes. Then it is sent to a sealed storage silo with silica gel desiccant. When ready for use, the relative humidity in the silo is controlled below 35%.

[0111] Step Two:

[0112] 1. Raw material screening: HDPE granules are screened using a melt indexer, and granules with a melt index <0.8g / 10min or >1.0g / 10min are removed to ensure raw material consistency;

[0113] 2. Cleaning and impurity removal: Put the screened HDPE granules into a WL1200 vortex cleaner, add 60℃ deionized water (water to granule mass ratio 3:1), and add 1% (relative to granule mass) of nonionic surfactant (fatty alcohol polyoxyethylene ether), stir and clean for 15 minutes to remove surface oil and dust.

[0114] 3. Dehydration and drying: After washing, the particles are sent to an LX800 centrifugal dehydrator and dehydrated at 1500 rpm for 2 minutes until the surface moisture content is reduced to below 5%; then they are sent to an LB1000 fluidized bed dryer and dynamically dried with hot air at 80℃ for 2 hours until the final moisture content is controlled at 0.3%.

[0115] 4. Crushing and size control: The dried HDPE granules are fed into the PSJ600 temperature-controlled crusher. The temperature of the crushing chamber is stabilized at 15℃ by circulating water. The gap between the crushing blades is adjusted to obtain irregular granules with a particle size distribution of 90-110 mesh, and the particle size qualification rate reaches 95%.

[0116] Step 3:

[0117] 1. Preparation of the reactor: Select a 500L stainless steel reactor, equipped with an anchor stirrer (30cm diameter blade) and a reflux condenser, and add 100kg of epoxy silane (3-glycidyl ether oxypropyltrimethoxysilane).

[0118] 2. Adding the antifungal agent: Start the stirrer and control the speed at 150 rpm. Slowly add 25 kg of IPBC antifungal agent through a constant pressure dropping funnel. The dropping rate should be kept stable at 1.25 kg / min. The whole process should take 20 minutes to avoid excessively high local concentrations.

[0119] 3. Heating reaction: After the addition is complete, raise the temperature of the hot water in the jacket of the reactor to 60°C, increase the stirring speed to 300 rpm, and continue the reaction for 45 minutes. During this period, the conversion rate of epoxy groups is detected through the sampling port. Stop the reaction when it reaches 90%.

[0120] 4. Product storage: After stopping heating, stir at 300 rpm for 10 minutes, and introduce the epoxy functionalized antifungal agent into a brown light-proof storage tank through the bottom valve. The storage tank is filled with nitrogen and pressurized (0.1 MPa) to prevent oxidation.

[0121] Step Four:

[0122] 1. Initial feeding: Start the SHR2000 high-speed hot mixer and add 300kg of pretreated HDPE granules, 20kg of zinc stearate, and 10kg of 1010 type antioxidant by weight.

[0123] 2. Preliminary mixing: Set the speed to 800 rpm and mix for 3 minutes. During this time, 50°C warm water is introduced through the jacket of the hot mixer to slightly soften the plastic particles and form a uniform mixture with the additives.

[0124] 3. Adding wood flour: While stirring, add 600 kg of pretreated wood flour at a rate of 10 kg / min through the side feed port. After all the wood flour has been added, increase the speed to 1200 rpm and mix for 6 minutes until the wood flour is completely coated with the plastic additive mixture and there are no obvious white wood flour particles.

[0125] 4. Adding the antifungal agent: Start the precision liquid feed pump and spray 50kg of epoxy functionalized antifungal agent into the mixer in the form of atomization (atomization pressure 0.3MPa). Reduce the speed to 600rpm and continue mixing for 7min. Finally, a mixture with uniform color and no clumps is obtained. The discharge temperature is controlled at 65℃.

[0126] Step 5:

[0127] 1. Equipment preparation: Select a TSE65 co-rotating twin-screw extruder with a screw diameter of 65mm and a length-to-diameter ratio of 40:1; the screw configuration from the feeding section to the die head is as follows: 10D length conveying section, 8D length kneading block group (kneading block angle 45°), 5D length reverse thread element, and 7D length homogenization section.

[0128] 2. Temperature setting: Set the temperature of each zone through the extruder temperature control system: feeding zone (zone 1) 120℃, compression zone (zone 2) 140℃, metering zone (zone 3) 160℃, reaction zone (zone 4) 170℃, and die head 180℃. After heating to the set temperature, hold for 30 minutes to ensure temperature stability.

[0129] 3. Extrusion control: The mixture is fed into the forced feeder, the feeding rate is set to 50 kg / h, the screw speed is controlled at 200 rpm, and the total residence time of the material in the extruder is about 2 minutes. In the 170℃ reaction zone, the epoxy groups of the epoxy functionalized mildew inhibitor undergo a ring-opening reaction with the hydroxyl groups on the surface of the wood flour and the HDPE molecular chain to form covalent bonds. Finally, a molten profile with a cross section of 120 mm × 15 mm is extruded from the die head.

[0130] Step Six:

[0131] 1. Vacuum shaping: The molten profile is immediately fed into a vacuum shaping mold (made of 304 stainless steel) that matches the cross-section of the floor. The vacuum pump is started to stabilize the vacuum level inside the mold at 0.07MPa. The surface of the profile is tightly adsorbed onto the cooling wall of the mold. At the same time, the cooling water circulation system is turned on, and the cooling water temperature is controlled at 12℃. The heat is carried away through the mold wall. The initial shaping time is 15s.

[0132] 2. Gradient Cooling: After initial shaping, the profile enters the first-stage cooling water tank (5m³ / s). 3 The water temperature is controlled at 20℃, and the material is cooled for 1 minute until the surface temperature drops below 50℃, completing the surface curing process. It is then transferred to a second-stage cooling water tank (8m³). 3 The water temperature is controlled at 15℃, and after cooling for 2 minutes, the core temperature of the profile drops to 38℃, effectively eliminating internal stress. After cooling, the straightness error of the profile is ≤0.5mm / m.

[0133] Step Seven:

[0134] 1. Traction and Conveying: Using a DL1000 tracked traction machine, the traction speed is set to 1.5m / min (synchronized with the extrusion speed) to pull the cooled profile out from the second-stage water tank. The track pressure is adjusted to 0.2MPa to avoid profile deformation.

[0135] 2. Fixed-length cutting: The profile is fed into the QG2000 automatic cutting machine. The measuring roller monitors the length in real time. When the length reaches 2000mm, the servo motor drives the alloy saw blade (120 teeth) to cut at high speed. The flatness error of the cut surface is ≤0.1mm.

[0136] 3. Connection structure processing: After cutting, the single plate is fed into the SM800 double-end milling machine. The two ends of the plate are milled simultaneously by the forming milling cutter (made of high-speed steel) to process the tenon and mortise connection structure. The tenon size error is controlled within ±0.05mm.

[0137] 4. Surface polishing: The board with the connecting structure is fed into the PG1200 automatic polishing machine. The surface is brushed with 800-grit sandpaper at a polishing rate of 2m / min to remove micro-burrs. The final surface roughness of the floor is Ra≤0.8μm.

[0138] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0139] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A kind of rot-proof mildew-proof wood plastic floor and its processing method, it is characterized by: The method comprises the following steps: Step S1: fine pretreatment of wood powder to obtain fine wood powder meeting the requirements of particle size and dryness; Step S2: pretreatment of plastic base material by recycled polyethylene plastic particles to remove impurities and adjust particle size; Step S3: in-situ synthesis of epoxy functional antifungal agent for subsequent covalent bonding with wood-plastic matrix; Step S4: mixing the pretreated plastic base material, wood powder and epoxy functional antifungal agent in sequence to obtain uniform material; Step S5: bonding and plasticizing of the material by reactive extrusion process to form a melt profile; Step S6: online sizing and gradient cooling of the melt profile obtained by reactive extrusion to eliminate internal stress and solidify the profile; Step S7: cutting and finishing the profile after gradient cooling and solidification to obtain finished anti-corrosion and anti-mildew wood-plastic floor.

2. The rot-proof and mildew-proof wood plastic floor and its processing method according to claim 1, characterized in that, The step S1 comprises the following steps: Step S11: wood waste from pine or fir is fed into a coarse crusher for preliminary crushing to obtain crushed material with a size not greater than 10 mm; Step S12: the wood crushed material is fed into a fine grinder for grinding, and the fine wood powder passing through a 100 mesh standard sieve is collected by an air flow sorting system; Step S13: the fine wood powder is evenly spread on a tray with a spreading thickness not greater than 5 cm, and then transferred to a blast drying oven; Step S14: the blast drying oven is started, and the temperature is raised from room temperature to 105℃ at a rate of 10℃ per hour, and the temperature is maintained for 4 hours, and the built-in stirring device is started every 1 hour during the drying process; Step S15: after the drying is completed, the wood powder is transferred to a sealed cooling tank, dry nitrogen is filled, and the temperature is cooled to below 35℃, and then the wood powder is input into a sealed storage bin with desiccant for standby.

3. The rot-proof and mildew-proof wood plastic floor and the processing method thereof according to claim 1, characterized in that, The step S2 comprises the following steps: Step S21: recycled high-density polyethylene plastic particles with a melt index of 0.8-1.0 g / 10 min are selected; Step S22: the high-density polyethylene particles are fed into a vortex cleaning machine, deionized water at 60℃ is used, and 1% non-ionic surfactant is added, and the cleaning is performed for 15 minutes to remove surface grease and dirt; Step S23: after the high-density polyethylene particles are cleaned, the surface moisture is removed by a centrifugal dewatering machine, and then the particles are sent to a fluidized bed dryer for dynamic drying at 80℃ for 2 hours; Step S24: the dried high-density polyethylene particles are sent to a temperature-controlled crusher, the crushing cavity is cooled by circulating water to maintain 15℃, and the plastic is crushed into irregular particles with a particle size distribution of 80-120 mesh.

4. The rot-proof and mildew-proof wood plastic floor and the processing method thereof according to claim 1, characterized in that, The step S3 comprises the following steps: Step S31: a reaction kettle equipped with an anchor type stirrer and a condensation reflux device is used, and a metered amount of epoxy silane is added; Step S32: the stirring device is started, the rotating speed is controlled at 150 rpm, and a metered amount of iodopropargyl carbamate antifungal agent is added through a constant pressure dropping funnel, and the dropping time lasts for 20 minutes; Step S33: after the dropping is completed, the jacket temperature of the reaction kettle is raised to 60℃, the stirring speed is increased to 300 rpm, and the reaction is continued for 40-50 minutes under the above conditions; Step S34, after the reaction is completed, stop heating, keep stirring, discharge the reaction product through the bottom valve of the reactor, and transfer the product to a nitrogen-filled storage tank for temporary storage.

5. The rot-proof and mildew-proof wood plastic floor and the processing method thereof according to claim 1, characterized in that, The step S4 includes the following steps: Step S41, start the high-speed thermal mixer, and sequentially add 30 parts of pretreated high-density polyethylene plastic particles, 2 parts of zinc stearate lubricant, and 1 part of 1010 type antioxidant according to weight; Step S42, mix at a speed of 800 rpm for 3 minutes to preliminarily bond the plastic components with low melt viscosity and the additives; Step S43, under continuous stirring, slowly add 60 parts of pretreated wood powder through the side feeding port, and after the wood powder is completely added, increase the speed to 1200 rpm and mix for 4-7 minutes to make the wood powder be fully wrapped by the plastic-additive mixture; Step S44, spray 5 parts of epoxy functional antifungal agent into the mixer in atomized form through a precision liquid feeding pump, reduce the speed to 600 rpm, and continue mixing for 5-8 minutes.

6. The rot-proof and mildew-proof wood plastic floor and the processing method thereof according to claim 1, characterized in that, The step S5 includes the following steps: Step S51, send the uniformly mixed material into the forced feeder, and stably feed it into the co-rotating twin-screw extruder through the forced feeder; the screw configuration of the twin-screw extruder is arranged in sequence from the feeding section to the die head as a conveying section, a kneading block group for high-strength shearing and mixing, a reverse thread element for establishing back pressure and prolonging residence time, and a homogenizing section; Step S52, set the temperature of each zone of the extruder; Step S53, control the screw speed to be 200 rpm, so that the total residence time of the material in the extruder is about 2 minutes; when the melt flows through the reaction zone at 170°C, the epoxy groups in the epoxy functional antifungal agent react with the hydroxyl groups on the surface of the wood powder particles and the high-density polyethylene molecular chain under the action of shearing and heat to realize covalent bonding.

7. The rot-proof and mildew-proof wood plastic floor and the processing method thereof according to claim 1, characterized in that, The step S6 includes the following steps: Step S61, immediately send the molten profile that has completed the reactive bonding out of the die head of the extruder into a vacuum shaping mold matched with the cross-sectional shape of the floor; Step S62, start the vacuum pump to maintain a vacuum degree of-0.07 MPa in the vacuum shaping mold, tightly adsorb the profile surface to the cooling wall surface of the shaping mold, and simultaneously start the cooling water circulation system of the shaping mold to control the cooling water temperature to be 12°C; Step S63, after the initial shaping by vacuum, send the profile into the first-stage cooling water tank, control the water temperature of the tank to be 20°C, cool for 1 minute, and complete the rapid solidification of the surface layer of the profile; Step S64, send the profile after the surface layer is solidified into the second-stage cooling water tank, control the water temperature of the tank to be 15°C, cool for 2 minutes, so that the temperature of the core of the profile is reduced to below 40°C, and the internal stress is eliminated.

8. The rot-proof and mildew-proof wood plastic floor and the processing method thereof according to claim 1, characterized in that, The step S7 includes the following steps: Step S71, use a crawler tractor to pull out the cooled profile from the cooling water tank at a constant speed synchronized with the extrusion speed; Step S72, guide the pulled-out profile into the workbench of the automatic cutting machine, and the measuring roller of the cutting machine monitors the length of the profile in real time; when the length reaches the preset 2000 mm, the servo motor drives the alloy saw blade to complete the transverse cutting; Step S73, the cut single floor board is transported to the double-end milling equipment, and the two ends of the board are simultaneously milled by the forming milling cutter on the equipment to process the connecting structure; Step S74, the board with the processed connecting structure is sent to the automatic polishing machine equipped with 800-mesh fine sandpaper to perform wire drawing treatment on the floor surface and remove micro burrs.

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