Preparation method of multi-layer solid wood composite floor with softwood layer pasted on poplar surface

Abstract

The present application relates to the technical field of composite floor manufacturing, and particularly relates to a method for manufacturing a multi-layer solid wood composite floor capable of simultaneously improving the strength, dimensional stability and surface passive protection function of fast-growing poplar, in particular a method for manufacturing a multi-layer solid wood composite floor with a softwood layer attached to the surface of poplar, comprising the following steps: 1) preparing an acrylic resin solution; 2) filling and reinforcing poplar veneer by resin impregnation; 3) laminating and compounding modified poplar veneer and unmodified poplar plywood; and 4) laminating and pressing the modified poplar veneer laminated material and the softwood adhesive layer to obtain the multi-layer solid wood composite floor with the softwood layer attached to the surface of the modified poplar plywood. The present application fills the cell cavities of poplar with acrylic resin to reinforce the poplar veneer, and through hot pressing and gluing, the modified poplar veneer, the unmodified poplar plywood substrate and the softwood layer are compounded into the multi-layer solid wood composite floor, which can effectively simultaneously improve the strength, dimensional stability and surface passive protection function of fast-growing poplar.

Description

Technical Field

[0001] This invention relates to the field of composite flooring manufacturing technology, and particularly to a method for preparing multi-layer solid wood composite flooring that can simultaneously improve the strength, dimensional stability and passive surface protection of fast-growing poplar, especially a method for preparing multi-layer solid wood composite flooring with a cork layer on the poplar surface. Background Technology

[0002] Poplar wood is abundant and inexpensive, making it widely used in non-load-bearing furniture components. However, its low density, light weight, low strength, and susceptibility to deformation limit its application in flooring, wooden doors and windows, and furniture structural components. In wood filling, commonly used wood filler resins are mostly water-soluble aldehyde resins, such as phenolic resin, urea-formaldehyde resin, and melamine resins, which have the drawback of formaldehyde release.

[0003] Therefore, using non-formaldehyde water-based resin to modify poplar wood will give it the advantages of being green and environmentally friendly, and is expected to solve the disadvantages of low strength and easy deformation of poplar wood, thereby expanding the application of poplar wood to flooring, furniture structural components, wooden doors and windows and other fields.

[0004] As people's living standards continue to improve, health-oriented homes with features such as safety, health, and passive protection have become a strong demand for people's living environment. Ordinary wooden home environments have the advantages of being green and healthy, but they cannot provide passive protection functions; especially in spaces where the elderly and children play, the surface hardness of wood panels (especially reinforced and modified wood) is relatively high, lacking cushioning and shock absorption functions, making it difficult to provide passive protection for these groups.

[0005] Cork is a natural polymer material derived from the outer periderm of the cork oak. The tree does not die after the bark is peeled off, and it can be recycled. It has functions such as heat insulation, shock absorption, and sound insulation, and has the potential to be applied in the field of passive protection.

[0006] Currently, there are also some cork-related patents. For example, in patent application number CN201420841706.6, there is a reinforced cork flooring. Its main structure includes a body, which is a layered structure. From top to bottom, it includes a surface layer, a wear-resistant layer, a waterproof layer, a cork decorative layer, a cork composite layer, and a reinforced installation base layer. The surface layer is a PU layer. The lower surface of the surface layer is bonded to the upper surface of the wear-resistant layer, the lower surface of the wear-resistant layer is bonded to the upper surface of the waterproof layer, the lower surface of the waterproof layer is bonded to the upper surface of the cork decorative layer, the lower surface of the cork decorative layer is bonded to the upper surface of the cork composite layer, and the lower surface of the cork composite layer is bonded to the upper surface of the reinforced installation base layer. The reinforced installation base layer is made of a hard material.

[0007] In summary, the aforementioned cork flooring primarily utilizes cork as a decorative layer, combined with a waterproof layer, a wear-resistant layer, and a surface layer to form a composite wood board structure. Its overall function is mainly to improve the wood board's resistance to deformation, but its passive protection effect is relatively poor.

[0008] Therefore, in today's increasingly popular trend of health and wellness home furnishings, this invention provides a flooring material that modifies poplar wood, combines it with cork, and uses a new process to create a flooring material that combines high structural stability, high strength, and passive protection functions, in order to significantly increase the added value of poplar wood and better solve the problems existing in the prior art. Summary of the Invention

[0009] To solve one of the above-mentioned technical problems, the present invention provides a method for preparing a multi-layer solid wood composite floor with a softwood layer laminated onto a poplar surface, comprising the following steps:

[0010] 1) Preparation of acrylic resin solution:

[0011] First, prepare a sodium hydroxide aqueous solution with pH=10, and add acrylic resin particles of a certain molecular weight to the alkaline sodium hydroxide aqueous solution. Heat and stir at 70°C to dissolve. Then, cool the liquid to room temperature and add a curing agent with a mass ratio of 10% to it. Stir evenly to obtain an acrylic resin solution.

[0012] 2) Resin-impregnated and filled reinforced poplar veneer:

[0013] The acrylic resin liquid obtained in step 1 above is used to impregnate poplar veneer and ensure that it is fully impregnated into the cell cavity of poplar veneer. Then, the poplar veneer is heat-cured and flattened by heat curing in a heat curing linkage system until the moisture content of the poplar veneer sample reaches below 10%, thus obtaining modified poplar veneer reinforced with acrylic resin.

[0014] 3) Laminated composite of modified poplar veneer and unmodified poplar plywood:

[0015] Using the modified poplar veneer from step 2 above as the surface layer and the unmodified poplar plywood as the base layer, the modified poplar veneer laminated lumber is obtained by hot pressing.

[0016] 4) Modified poplar veneer laminated with cork is laminated to obtain multi-layer solid wood composite flooring with a cork layer on the surface of modified poplar plywood.

[0017] In any of the above embodiments, it is preferred that the acrylic resin particles mentioned in step 1 are styrene-acrylic acid copolymer resins with a molecular weight of less than 10,000 and an acrylic resin solid content of less than 30% when dissolved in sodium hydroxide solution.

[0018] In any of the above embodiments, it is preferred that the curing agent is a aziridine crosslinking agent.

[0019] In any of the above schemes, it is preferred that the process of impregnating poplar veneer with acrylic resin in step 2 is to vacuum at 0.01-0.09MPa for 0.1-10h, and then pressurize at 0.1-1.5MPa for 0.1-10h.

[0020] In any of the above schemes, the specific requirements of the heating and curing process are as follows: the hot pressing pressure is 5-10 MPa, the temperature is first 50℃-70℃ for 0.1-10h, then 70℃-90℃ for 0.1-10h, and finally 90℃-120℃ until the moisture content of the poplar veneer sample is less than 10%.

[0021] In any of the above embodiments, it is preferred that the thickness of the poplar veneer is 1-3 mm.

[0022] In any of the above schemes, it is preferred that the overall thickness of the modified poplar veneer laminated lumber in step 3 is 6-15mm, the upper and lower surfaces are single layers of modified poplar veneer, and the middle substrate is 3-12mm of unmodified poplar plywood.

[0023] In any of the above solutions, it is preferred that the cork layer in step 4 is a cork pad bonded with polyurethane flexible adhesive, with a thickness of 2-4 mm.

[0024] The adhesives required for bonding the interlayers in steps 3 and 4 are cottonseed or soybean modified protein adhesives, or non-formaldehyde adhesives such as polyurethane adhesives; the adhesive is applied to both sides, with an application rate of 200-500 g / m2, a hot-pressing temperature of 135°C, a hot-pressing time of 6 min, and a hot-pressing pressure of 1.0 MPa; a layer of cork is applied to both the top and bottom sides of the modified poplar veneer laminated lumber; the surface of the cork layer is further coated with paint.

[0025] In any of the above embodiments, it is preferred that the multi-layer solid wood composite flooring includes modified poplar veneer and unmodified poplar plywood arranged sequentially from top to bottom. The modified poplar veneer A and the unmodified poplar plywood B are hot-pressed together to obtain a surface-modified poplar veneer laminated material C. Both the upper and lower surfaces of the poplar veneer laminated material C are laminated with cork, so that the cork layer D is respectively attached to the upper and lower surfaces of the poplar veneer laminated material.

[0026] In any of the above embodiments, it is preferred that the heating and curing linkage system includes a fixedly suspended positioning beam, a hot pressing mechanism installed at the bottom of the positioning beam, a conveyor unit arranged below the hot pressing mechanism, and a glue spraying mechanism installed at the bottom of the positioning beam on the left side of the hot pressing mechanism. The glue spraying mechanism is used to spray glue onto the board material conveyed by the conveyor unit below it and evenly roll it onto the upper surface of the board material.

[0027] In any of the above embodiments, it is preferred that the conveyor unit includes a main belt conveyor and an auxiliary belt conveyor is arranged at intervals on the right side of the main belt conveyor. The auxiliary belt conveyor works in conjunction with the main belt conveyor to realize the reciprocating conveying of the sheet material on it in the horizontal direction.

[0028] In any of the above embodiments, preferably, the glue spraying mechanism includes a plurality of glue storage tanks fixedly installed below the positioning beam on the left side of the hot pressing mechanism, spaced apart along the width of the sheet below. Each glue storage tank has a glue spraying nozzle with a flow pump installed at the glue outlet at its bottom. The outlet of each glue spraying nozzle is oriented towards the sheet below. A roller pressing flexible roller is spaced apart on the left side of each glue storage tank. The front and rear ends of the roller pressing flexible roller are respectively hinged to end seats at corresponding positions via a central shaft. A synchronous lifting cylinder is fixedly connected to the top of each end seat. The top of the cylinder of each of the two synchronous lifting cylinders is fixedly installed at the bottom of the positioning beam. When working, the two synchronous lifting cylinders move synchronously and in the same direction. The coordinated movement of the two synchronous lifting cylinders drives the roller pressing flexible roller to move up and down.

[0029] In any of the above embodiments, it is preferred that a sheet metal flipping mechanism is provided on the right side of the auxiliary belt conveyor, the sheet metal flipping mechanism being used to control the 180-degree flipping of the sheet metal transported above it.

[0030] In any of the above embodiments, it is preferred that two sheet material descent buffers are installed in the gap between the main belt conveyor and the auxiliary belt conveyor, spaced apart and fixedly arranged along the sheet material conveying direction. The sheet material descent buffer includes a lifting and stopping cylinder assembly fixedly installed on the ground. The lifting and stopping cylinder assembly has two stopping cylinders spaced apart along the width direction of the sheet material. A horizontal long seat is fixedly installed on the top of the two piston rods of the lifting and stopping cylinder assembly. A flexible rubber buffer friction airbag is fixed on the top of the horizontal long seat along the width direction of the sheet material. The top of the flexible rubber buffer friction airbag is used to support and buffer the sheet material falling towards it.

[0031] In any of the above embodiments, preferably, the sheet metal turning mechanism includes a vertical mounting base fixedly installed on the right side of the auxiliary belt conveyor. A friction pusher seat is movably hinged to the top of the vertical mounting base. The surface of the friction pusher seat is provided with an anti-slip layer. A multi-stage telescopic cylinder for turning and pushing is provided below the middle of the friction pusher seat. A horizontal welded fixed seat is provided below the multi-stage telescopic cylinder for turning and pushing. The bottom of the cylinder of the multi-stage telescopic cylinder for turning and pushing is movably hinged to the top of the horizontal welded fixed seat. The piston rod of the multi-stage telescopic cylinder for turning and pushing is connected to the bottom of the friction pusher seat. The multi-stage telescopic cylinder for turning and pushing drives the friction pusher seat to tilt and turn to the upper left by telescopic movement, thereby turning the sheet metal on it 180 degrees. The sheet metal in the turned state will be cushioned by the flexible rubber buffer friction airbag during the process of falling to the left, and will be turned back to the horizontal state under the slow descent action of the lifting and stopping cylinder group.

[0032] In any of the above embodiments, it is preferred that the hot pressing mechanism includes a horizontally arranged electric heating hot pressing plate, and a hot pressing lifting cylinder is installed at each of the four top corners of the electric heating hot pressing plate. The top of the cylinder of each hot pressing lifting cylinder is fixedly installed at the bottom of the positioning crossbeam, and the bottom of the piston rod of each hot pressing lifting cylinder is connected to the electric heating hot pressing plate. Each hot pressing lifting cylinder moves synchronously and in the same direction when it moves.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1. This preparation method utilizes acrylic resin to fill the cell cavities of poplar wood to enhance the poplar veneer. Through hot pressing and gluing, the modified poplar veneer is combined with the unmodified poplar plywood substrate and the cork layer to form a multi-layer solid wood composite floor. This method can effectively improve the strength, dimensional stability and passive surface protection function of fast-growing poplar wood simultaneously.

[0035] 2. In this preparation process, the acrylic resin, with the help of its carboxylic acid groups, dissolves in alkaline solution and achieves its own curing and cross-linking through aziridine functional groups. When introduced into the veneer, it can further cross-link and combine with the hydroxyl groups of the wood during curing to form a whole, thereby producing modified poplar veneer reinforced with acrylic resin. Combined with a compaction treatment of 5-10 MPa, the poplar veneer is endowed with high hardness, high wear resistance, high bending strength and high dimensional stability.

[0036] 3. By bonding modified poplar veneer with unmodified ordinary poplar plywood, the modified veneer as the surface layer can effectively solve the bottleneck problems of low strength and poor dimensional stability of the substrate used for flooring, and can also save the cost of overall modified veneer laminated lumber.

[0037] 4. The cork layer designed in this invention is soft in texture and has compression resilience, energy absorption and shock absorption properties; a cork layer is covered on the upper and lower surfaces of the modified poplar laminated wood, which respectively endows the multi-layer solid wood composite floor with impact resistance and sound insulation functions.

[0038] 5. The multi-layer solid wood composite flooring of the present invention organically combines the filling, reinforcement, and dimensional stabilization properties of poplar with the filling and reinforcement properties of acrylic resin, and also leverages the rebound and shock absorption advantages of cork. Ultimately, poplar is applied to the flooring field, exhibiting excellent performance and added functionality, and has the potential for high added value utilization.

[0039] 6. This preparation method solves the bottleneck problems of low mechanical strength, large deformation and poor surface protection function of poplar wood flooring. Attached Figure Description

[0040] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or components are generally identified by similar reference numerals. In the drawings, the elements or components are not necessarily drawn to scale.

[0041] Figure 1 This is a schematic diagram of the heating and curing linkage system of the present invention.

[0042] Figure 2 This is a schematic diagram of the sheet material flipping mechanism in the heating and curing linkage system of the present invention during operation.

[0043] Figure 3 This is a structural schematic diagram of the multi-layer solid wood composite flooring of the present invention.

[0044] In the diagram: 1. Positioning beam; 2. Sheet material; 3. Main belt conveyor; 4. Auxiliary belt conveyor; 5. Glue storage tank; 6. Glue spray nozzle; 7. Roller-pressed flexible roller; 8. Central shaft; 9. End support; 10. Synchronous lifting cylinder; 11. Material blocking cylinder; 12. Horizontal long seat; 13. Flexible rubber buffer friction airbag; 14. Vertical mounting base; 15. Friction pushing seat; 16. Anti-slip layer; 17. Tilting and pushing multi-stage telescopic cylinder; 18. Horizontal welded fixed seat; 19. Electric heating hot press plate; 20. Hot press lifting cylinder; A. Modified poplar veneer; B. Unmodified poplar plywood; C. Poplar veneer laminated lumber; D. Softwood layer. Detailed Implementation

[0045] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore merely examples and should not be used to limit the scope of protection of the present invention. The specific structure of the present invention is as follows: Figure 1-3 As shown in the image.

[0046] Example 1:

[0047] A method for preparing a multi-layer solid wood composite floor with a poplar wood surface covered with a cork layer includes the following steps:

[0048] 1) Preparation of acrylic resin solution: First, prepare a sodium hydroxide aqueous solution with pH=10. Then, add styrene-acrylic acid copolymer resin (referred to as acrylic resin) with a molecular weight of 1700 to the alkaline solution and heat and stir at 70°C to dissolve it, obtaining an acrylic resin alkaline solution with a solid content of 25%. Then, after cooling the liquid to room temperature, add aziridine curing agent with a mass ratio of 10% of the resin and stir evenly to obtain the acrylic resin solution.

[0049] 2) Resin-filled reinforced poplar veneer: The mixture obtained in step one was impregnated into the cell cavities of 2 mm thick poplar veneer using a process of vacuum impregnation (0.08 MPa, 40 min) followed by pressure impregnation (0.5 MPa, 60 min). The mixture was then heated at 5 MPa, 50 °C, and 70 °C for 1 h each. Finally, the sample was dried at 103 °C until the moisture content was less than 10%, resulting in modified poplar veneer reinforced with acrylic resin.

[0050] 3) Laminate modified veneer with unmodified poplar plywood: Cottonseed protein glue is applied to one side of the surface of two modified poplar veneers from step two, with a glue application amount of 350g / m2; then laminated with 9mm thick unmodified poplar plywood, and hot-pressed for 6min at a hot-pressing temperature of 135°C and a hot-pressing pressure of 1.0MPa to obtain surface-modified poplar veneer laminated lumber;

[0051] 4) Modified poplar veneer laminated with cork: The modified poplar veneer laminated with cork (2mm thick bottom and 3mm thick top) obtained in step 3 is hot-pressed with cottonseed protein glue at 135°C, 1.0MPa, and 6min. Then, two layers of water-based UV polyurethane varnish (total coating amount of 80 g / m3) are applied to the surface of the top cork layer to obtain a multi-layer solid wood composite floor with a cork layer on the modified poplar plywood surface. Tests showed that the modified poplar plywood had a surface hardness of 4600N, an abrasion value of only 57 mg / 100r, a water absorption rate of 51%, a water absorption thickness swelling rate of 4.7%, and a water absorption width swelling rate of 3.9%. The multi-layer engineered wood flooring had an elastic modulus of 7800MPa, a static bending strength of up to 67MPa, a surface abrasion value of only 80 mg / 100r, a surface stain resistance rating of 5, an adhesion rating of 2, a gloss level of 6.5, a formaldehyde emission level of 0.8mg / l, and a light fastness rating of 4. Overall performance met the physical and chemical performance requirements of the national standard GB / T 18103-2013 for flooring substrates.

[0052] Example 2:

[0053] A method for preparing a multi-layer solid wood composite floor with a poplar wood surface covered with a cork layer includes the following steps:

[0054] 1) Preparation of acrylic resin solution: First, prepare a sodium hydroxide aqueous solution with pH=10. Then, add styrene-acrylic acid copolymer resin (referred to as acrylic resin) with a molecular weight of 8600 to the alkaline liquid. Heat and stir at 70°C to dissolve, and obtain an acrylic resin alkaline solution with a solid content of 25%. Then, after cooling the liquid to room temperature, add aziridine curing agent with a mass ratio of 10% of the resin and stir evenly to obtain the acrylic resin solution.

[0055] 2) Resin-filled reinforced poplar veneer: The mixture obtained in step one was impregnated into the cell cavities of 3 mm thick poplar veneer using a process of vacuum impregnation (0.08 MPa, 40 min) followed by pressure impregnation (0.5 MPa, 60 min). The mixture was then heated at 5 MPa, 50 °C, and 70 °C for 1 h each. Finally, the sample was dried at 103 °C until the moisture content was less than 10%, resulting in modified poplar veneer reinforced with acrylic resin.

[0056] 3) Laminate modified veneer with unmodified poplar plywood: Cottonseed protein glue is applied to one side of the surface of two modified poplar veneers from step two, with a glue application amount of 350g / m2; then laminated with 9mm thick unmodified poplar plywood, and hot-pressed for 8min at a hot-pressing temperature of 135℃ and a hot-pressing pressure of 1.5MPa to obtain surface-modified poplar veneer laminated lumber;

[0057] 4) Modified poplar veneer laminated with cork: The modified poplar veneer laminated with the modified poplar veneer laminated with the modified poplar veneer laminated with the modified poplar veneer laminated with the modified poplar veneer laminated with the modified poplar veneer laminated with the modified poplar veneer laminated with the modified poplar veneer laminated with the modified poplar veneer laminated with the cork layer is hot-pressed together with cottonseed protein glue. The hot-pressing temperature is 135℃, the hot-pressing pressure is 1.5MPa, and the hot-pressing time is 10min. Then, two layers of water-based UV polyurethane paint (total paint amount is 80 g / m3) are applied to the surface of the cork layer to obtain the multi-layer solid wood composite flooring with the modified poplar plywood surface covered with cork layer.

[0058] Tests showed that the modified poplar plywood had a surface hardness of 4300N, an abrasion value of only 59 mg / 100r, a water absorption rate of 50%, a water absorption thickness swelling rate of 4.8%, and a water absorption width swelling rate of 3.7%. The multi-layer engineered wood flooring had an elastic modulus of 7200MPa, a static bending strength of up to 65MPa, a surface abrasion value of only 80 mg / 100r, a surface stain resistance rating of 5, an adhesion rating of 2, a gloss level of 6.5, a formaldehyde emission level of 0.8mg / l, and a light fastness rating of 4. Overall performance met the physical and chemical performance requirements of the national standard GB / T 18103-2013 for flooring substrates.

[0059] Example 3:

[0060] The difference from Embodiment 2 is that this embodiment also includes a heating and curing linkage system. The heating and curing linkage system includes a fixedly suspended positioning beam 1, a hot pressing mechanism installed at the bottom of the positioning beam 1, a conveyor unit arranged below the hot pressing mechanism, and a glue spraying mechanism installed at the bottom of the positioning beam 1 on the left side of the hot pressing mechanism. The glue spraying mechanism is used to spray glue onto the board material 2 conveyed by the conveyor unit below it and evenly roll it onto the upper surface of the board material 2.

[0061] The heating and curing linkage system is mainly used in the heating and curing process in step 2 above to convey, apply glue, and hot-press the various boards. The conveyor unit in this system can realize the horizontal reciprocating conveying of the boards it conveys. When the board is conveyed to the position, it can be located directly below the hot-pressing mechanism. By starting the hot-pressing mechanism, the board below can be hot-pressed. In addition, when the board needs to be glued before hot-pressing, it can be conveyed to the area below the glue spraying and gluing mechanism to complete the glue spraying and roller gluing. After the glue is applied, the glued board is conveyed to the right to the area directly below the hot-pressing mechanism for hot-pressing.

[0062] In any of the above embodiments, it is preferred that the conveyor unit includes a main belt conveyor 3, and an auxiliary belt conveyor 4 is arranged at intervals on the right side of the main belt conveyor 3. The auxiliary belt conveyor 4 cooperates with the main belt conveyor 3 to realize the reciprocating conveying of the plate material 2 on it in the horizontal direction.

[0063] Both the main belt conveyor 3 and the auxiliary belt conveyor 4 can have their lifting height controlled as needed. The lifting function is existing technology and will not be described in detail here.

[0064] In any of the above embodiments, it is preferred that the glue spraying mechanism includes a plurality of glue storage tanks 5 fixedly installed below the positioning beam 1 on the left side of the hot pressing mechanism, spaced apart along the width direction of the sheet 2 below it. Each glue storage tank 5 has a glue spraying nozzle 6 with a flow pump installed at the glue outlet at its bottom. The outlet of each glue spraying nozzle 6 is set towards the sheet below. A roller pressing flexible roller 7 is spaced apart on the left side of each glue storage tank 5. The front and rear ends of the roller pressing flexible roller 7 are respectively hinged to the end seats 9 at corresponding positions through a central shaft 8. A synchronous lifting cylinder 10 is fixedly connected to the top of each end seat 9. The top of the cylinder of each of the two synchronous lifting cylinders 10 is fixedly installed at the bottom of the positioning beam 1. When working, the two synchronous lifting cylinders 10 move synchronously and in the same direction. The two synchronous lifting cylinders 10 cooperate to drive the roller pressing flexible roller 7 to rise and fall.

[0065] When the glue spraying nozzles 6 on the glue spraying mechanism are started, they can spray an appropriate amount of glue onto the surface of the board material conveyed below. After the glue spraying is completed, the board material continues to be conveyed forward. By controlling the two synchronous lifting cylinders 10, the corresponding roller pressure flexible rollers 7 below are driven to contact the board material in motion, thereby achieving uniform roller pressure on the surface of the board material while it is in motion, and finally achieving the purpose of controlling the uniformity of the surface material. During the glue spraying process, the spraying amount can be controlled by controlling the opening degree of the flow pump. The glue application amount is 350g / m2.

[0066] In any of the above embodiments, it is preferred that a sheet metal turning mechanism is provided on the right side of the auxiliary belt conveyor 4, the sheet metal turning mechanism being used to control the 180-degree turning of the sheet metal transported above it.

[0067] In any of the above embodiments, it is preferred that two sheet material descent buffers are installed in the gap between the main belt conveyor 3 and the auxiliary belt conveyor 4, which are spaced apart and fixedly arranged along the conveying direction of the sheet material 2. The sheet material descent buffer includes a lifting and blocking cylinder assembly fixedly installed on the ground. The lifting and blocking cylinder assembly has two blocking cylinders 11 spaced apart along the width direction of the sheet material. A horizontal long seat 12 is fixedly installed on the top of the two piston rods of the lifting and blocking cylinder assembly. A flexible rubber buffer friction airbag 13 is fixed on the top of the horizontal long seat 12 along the width direction of the sheet material 2. The top of the flexible rubber buffer friction airbag 13 is used to support and buffer the sheet material 2 falling towards it.

[0068] The two spaced-apart sheet material descent buffers have two functions. First, during the conveying of the sheet material to the right, when the left end of the sheet material just moves to the right side of the right sheet material descent buffer, the buffer can be raised above the top of the auxiliary belt conveyor 4. At this time, the sheet material flipping mechanism can be activated, pushing the right end of the sheet material up. This causes the left end of the sheet material to tend to move to the left. The right sheet material descent buffer can then prevent the sheet material from moving to the left. Second, when the right side of the sheet material is pushed up and flips to the left, the left sheet material descent buffer can be raised to a suitable height, thus buffering the sheet material as it falls to the left. Finally, as the left sheet material descent buffer continues to descend, the sheet material smoothly changes position to a horizontal state after flipping.

[0069] In any of the above embodiments, preferably, the sheet metal turning mechanism includes a vertical mounting base 14 fixedly installed on the right side of the auxiliary belt conveyor 4. A friction pusher 15 is movably hinged to the top of the vertical mounting base 14. The surface of the friction pusher 15 is provided with an anti-slip layer 16. A multi-stage telescopic cylinder 17 for turning and pushing is provided below the middle of the friction pusher 15. A horizontal welded fixed base 18 is provided below the multi-stage telescopic cylinder 17. The bottom of the cylinder of the multi-stage telescopic cylinder 17 is movably hinged to the top of the horizontal welded fixed base 18. The piston rod of the multi-stage telescopic cylinder 17 is connected to the bottom of the friction pusher 15. The multi-stage telescopic cylinder 17 drives the friction pusher 15 to tilt and turn to the upper left by telescopic movement, thereby turning the sheet metal on it 180 degrees. The sheet metal in the turned state will be cushioned by the flexible rubber buffer friction airbag 13 during the process of falling to the left, and will be turned back to the horizontal state under the slow descent action of the lifting and blocking cylinder group.

[0070] When the sheet metal flipping mechanism is working, it mainly relies on the extension of the multi-stage telescopic cylinder 17 to drive the friction push seat 15 at the top of the piston rod of the sheet metal to push the bottom right side of the sheet metal, thereby making the right side of the sheet metal tilt upwards, eventually making it exceed the vertical state and continue to flip to the left. During the flipping to the left, the flexible rubber buffer friction airbag 13 of the sheet metal descent buffer can be used to support and buffer, eventually driving the sheet metal to a stable horizontal state.

[0071] In any of the above embodiments, it is preferred that the hot pressing mechanism includes a horizontally arranged electric heating hot pressing plate 19, and a hot pressing lifting cylinder 20 is respectively installed at the top four corners of the electric heating hot pressing plate 19. The top of the cylinder of each hot pressing lifting cylinder 20 is fixedly installed at the bottom of the positioning crossbeam 1, and the bottom of the piston rod of each hot pressing lifting cylinder 20 is connected to the electric heating hot pressing plate 19. Each hot pressing lifting cylinder 20 moves synchronously and in the same direction when it moves.

[0072] When hot pressing is required on the sheet material, each hot pressing lifting cylinder 20 can be controlled to descend synchronously to drive the electrically heated hot pressing plate 19 to descend, and finally the sheet material is pressure hot pressed into shape.

[0073] This preparation method utilizes acrylic resin to fill the cell cavities of poplar veneer, reinforcing it. Through hot-press bonding, the modified poplar veneer is combined with an unmodified poplar plywood substrate and a softwood layer to form a multi-layer solid wood composite flooring. This effectively and simultaneously improves the strength, dimensional stability, and passive surface protection of fast-growing poplar. In this process, the acrylic resin, with its carboxylic acid groups, dissolves in alkaline solutions and achieves self-curing and cross-linking through aziridine functional groups. When introduced into the veneer, it further cross-links and integrates with the hydroxyl groups of the wood during curing, thus producing acrylic resin-filled and reinforced modified poplar veneer. Combined with a 5-10 MPa compaction treatment, this imparts high surface hardness, high wear resistance, high bending strength, and high dimensional stability to the poplar veneer. Laminating the modified poplar veneer with unmodified ordinary poplar plywood, using the modified veneer as the surface layer, effectively solves the bottleneck problems of low strength and poor dimensional stability inherent in flooring made with the substrate, while also saving on the overall cost of modified veneer laminated lumber. The cork layer designed in this invention is soft in texture and possesses compression resilience and energy absorption / shock-damping properties. A cork layer is applied to both the upper and lower surfaces of the modified poplar laminated lumber, respectively endowing the multi-layer solid wood composite flooring with impact resistance and sound insulation functions. This multi-layer solid wood composite flooring organically combines the filling and reinforcement properties of acrylic resin with the dimensional stabilizing properties of poplar, while also leveraging the resilience and shock-damping advantages of cork. Ultimately, this allows poplar to be used in the flooring industry, exhibiting excellent performance and added functionality, with the potential for high added value. This preparation method solves the bottleneck problems of low mechanical strength, large deformation, and poor surface protection in poplar flooring.

[0074] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. For those skilled in the art, any alternative improvements or modifications made to the embodiments of the present invention fall within the protection scope of the present invention.

[0075] Any aspects of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A heating and curing linkage system used in the preparation method of multi-layer solid wood composite flooring with a cork layer laminated on the surface of poplar wood, characterized in that, The system is specifically applied to the heating and curing process of the preparation method to achieve hot-pressing and flattening of poplar veneer. The system includes a fixedly suspended positioning beam, a hot-pressing mechanism installed at the bottom of the positioning beam, a conveyor unit set below the hot-pressing mechanism, and a glue spraying mechanism installed at the bottom of the positioning beam on the left side of the hot-pressing mechanism. The glue spraying mechanism is used to spray glue onto the board material conveyed by the conveyor unit below and to evenly roll the glue onto the upper surface of the board material. The conveyor unit reciprocates horizontally to transport the sheet material it is conveying. When the sheet material is transported to a position directly below the hot pressing mechanism, the hot pressing mechanism is activated to perform hot pressing treatment on the sheet material below it. When the sheet material needs to be glued before hot pressing, the sheet material is conveyed to the bottom of the glue spraying and gluing mechanism to complete the glue spraying and roller gluing. After the glue is applied, the glued sheet material is conveyed to the right to the bottom of the hot pressing mechanism for hot pressing. The conveyor unit includes a main belt conveyor, and auxiliary belt conveyors are arranged at intervals on the right side of the main belt conveyor; Two sheet material deceleration buffers are installed in the gap between the main belt conveyor and the auxiliary belt conveyor, spaced apart and fixedly arranged along the sheet material conveying direction. The sheet material deceleration buffer includes a lifting and blocking cylinder assembly fixedly installed on the ground. The lifting and blocking cylinder assembly has two blocking cylinders spaced apart along the width direction of the sheet material. A horizontal long seat is fixedly installed on the top of the two piston rods of the lifting and blocking cylinder assembly. A flexible rubber buffer friction airbag is fixed on the top of the horizontal long seat along the width direction of the sheet material. The top of the flexible rubber buffer friction airbag is used to support and buffer the sheet material falling towards it. A sheet metal turning mechanism is provided on the right side of the auxiliary belt conveyor. The sheet metal turning mechanism includes a vertical mounting base fixed to the right side of the auxiliary belt conveyor. A friction push seat is movably hinged to the top of the vertical mounting base. The surface of the friction push seat is provided with an anti-slip layer. A multi-stage telescopic cylinder for turning and pushing is provided below the middle of the friction push seat. A horizontal welded fixed seat is provided below the multi-stage telescopic cylinder for turning and pushing. The bottom of the cylinder of the multi-stage telescopic cylinder for turning and pushing is movably hinged to the top of the horizontal welded fixed seat. The piston rod of the multi-stage telescopic cylinder for turning and pushing is hinged to the bottom of the friction push seat. The multi-stage telescopic cylinder for turning and pushing drives the friction push seat to tilt and turn to the upper left by telescopic movement, and turns the sheet metal on it by 180 degrees. During the process of conveying the sheet to the right, when the left end of the sheet just moves to the right side of the sheet deceleration buffer on the right, the sheet deceleration buffer on the right is raised and raised above the top of the auxiliary belt conveyor. At this time, the sheet flipping mechanism is activated to push the right end of the sheet up, so that the left end of the sheet tends to move to the left. The sheet deceleration buffer on the right prevents the sheet from moving to the left. When the right side of the sheet is pushed up and flips to the left, the sheet deceleration buffer on the left rises to a suitable height and buffers the sheet as it falls to the left. As the sheet deceleration buffer on the left continues to descend, the sheet is smoothly repositioned to a horizontal state after flipping.

2. The heating and curing linkage system according to claim 1, characterized in that, The hot pressing mechanism includes an electrically heated hot pressing plate. A hot pressing lifting cylinder is installed at each of the four top corners of the electrically heated hot pressing plate. The top of the cylinder of each hot pressing lifting cylinder is fixed to the bottom of the positioning crossbeam. The bottom of the piston rod of each hot pressing lifting cylinder is connected to the electrically heated hot pressing plate. Each hot pressing lifting cylinder moves synchronously and in the same direction during movement.

3. The heating and curing linkage system according to claim 2, characterized in that, The glue spraying mechanism includes several glue storage tanks fixedly installed below the positioning beam on the left side of the hot pressing mechanism, spaced apart along the width of the sheet below. Each glue storage tank has a glue spraying nozzle with a flow pump installed at its bottom outlet. The outlet of each glue spraying nozzle faces the sheet below. A flexible roller is spaced apart on the left side of each glue storage tank. The front and rear ends of the flexible roller are respectively hinged to end seats at corresponding positions via a central shaft. A synchronous lifting cylinder is fixedly connected to the top of each end seat. The top of the cylinders of two synchronous lifting cylinders are fixedly installed at the bottom of the positioning beam. When working, the two synchronous lifting cylinders move synchronously and in the same direction. The coordinated movement of the two synchronous lifting cylinders drives the lifting of the flexible roller.

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