Deformation control device for non-polyvinyl chloride wood-plastic plate, production line, and use

Abstract

The present invention relates to the technical field of floor manufacturing, and in particular to a deformation control device for a non-polyvinyl chloride wood-plastic plate, a production line, and a use. The deformation control device comprises a mold fixedly connected to an extruder and used for outputting a semi-finished plate, and a traction roller assembly obtained by combining a plurality of traction rollers and used for pulling and shaping the semi-finished plate. The mold comprises an output port used for outputting the semi-finished plate, and an included angle is formed between the output port and the horizontal plane, such that the direction in which the semi-finished plate is pulled by the traction roller assembly along the output port does not coincide with the direction of the gravity borne by the semi-finished plate, and the included angle between the two directions is smaller than 90 degrees. The deformation control device provided by the present application changes the angle relationship between the output port of the mold and the horizontal plane, effectively overcoming the problems of shrinkage and warpage of traditional plates with polyvinyl chloride as a raw material during extrusion.

Description

A non-polyvinyl chloride wood-plastic board deformation control device, production line and application Technical Field

[0001] The present invention relates to the technical field of floor manufacturing, and in particular to a deformation control device, a production line and applications of a non-polyvinyl chloride wood-plastic board. Background Art

[0002] Flooring with three-dimensional wood grain has become a popular choice in the panel manufacturing industry. By utilizing advanced technologies and materials, these floors can create products that resemble the look and feel of natural wood. These three-dimensional wood grain floors offer improved performance and durability, meeting consumer demand for high-quality, low-maintenance, and low-cost products. Furthermore, the manufacturing process for these products reduces reliance on natural resources, thereby protecting the environment and promoting sustainable development.

[0003] Currently, three-dimensional wood-grain flooring typically uses polyvinyl chloride (PVC) sheets as a base material, onto which the three-dimensional wood grain is printed or stacked. PVC sheets offer advantages in the production of three-dimensional wood-grain flooring due to their wear resistance, waterproofness, and corrosion resistance.

[0004] For example, the patent with authorization announcement number CN112095967B discloses a multi-level synchronous patterned molded round-edge PVC panel, which includes a panel body. The panel body comprises, from top to bottom, a UV paint layer, a PVC wear-resistant layer, a PVC patterned film layer, a PVC substrate board, and a PVC base material layer. The panel surface contains a synchronous patterned simulated three-dimensional texture, and the panel body has arc edges and a locking structure around it. The panels can be locked and spliced ​​with each other through the locking structure.

[0005] Patent publication number CN114953665A discloses a process for preparing PVC flooring and the resulting product. The specific steps include sequentially laminating a PVC substrate layer, a PVC printing layer, and a PVC pre-coated film, and then laminating them in one go to obtain the finished PVC flooring.

[0006] However, the use of PVC wood-based panels presents several significant drawbacks, including recycling and environmental issues. First, due to the structural characteristics of PVC, its recycling and reuse are difficult, leading to resource waste. Second, PVC releases hazardous substances during production, use, and disposal, posing potential risks to the environment and human health. Therefore, for environmental reasons, certain restrictions are needed on the use of PVC in the flooring industry.

[0007] To address the shortcomings of PVC-based panels, researchers have begun exploring alternative materials. Polyolefins are considered a potential alternative. Polypropylene, a typical example of a non-PVC material, exhibits excellent physical properties and chemical stability. It can be used to produce panels that mimic the texture and feel of natural wood. Furthermore, polypropylene is recyclable, helping to reduce resource waste and environmental pollution.

[0008] For example, the patent application publication number CN 108659333 A provides a non-polyvinyl chloride surface covering, comprising: a base material layer; an intermediate layer located on the base material layer, wherein the intermediate layer includes a middle material layer; and a transparent wear-resistant layer located on the intermediate layer, wherein the transparent wear-resistant layer comprises: 40 to 94.95 weight percent of polyolefin, 5 to 50 weight percent of polyolefin elastomer or polyolefin plastomer, and 0.05 to 10 weight percent of a processing aid.

[0009] For example, patent application publication number CN 111267448 A discloses a NON-PVC substrate 3D printed floor, which includes a NON-PVC substrate layer, a balancing layer and a solid wood layer sequentially arranged on the NON-PVC substrate layer, a UV primer layer provided on the surface of the solid wood layer, a white UV paint layer provided on the UV primer layer, a printed pattern layer provided on the surface of the white UV paint layer, and a concave-convex effect layer provided on the surface of the printed pattern layer.

[0010] However, polyolefin materials (e.g., polypropylene) have a high thermal shrinkage, which means that when the temperature changes during the manufacturing process, polypropylene will shrink. This thermal shrinkage may cause the board to shrink unevenly during the cooling process, thereby causing warping, and ultimately leading to uneven and unstable floors. In addition, the wear resistance of polyolefin materials is also somewhat inferior to that of polyvinyl chloride. Therefore, in order to overcome these problems, it is necessary to improve the preparation method and production equipment of boards using polyolefin materials as raw materials, so as to help improve the quality, stability and environmental friendliness of floors with three-dimensional wood grain.

[0011] Summary of the Invention

[0012] The present invention aims to overcome the defects of the prior art non-PVC wood-plastic board in that the warping rate is high during the molding process, resulting in unevenness and instability of the final floor. Therefore, a non-PVC wood-plastic board deformation control device, production line and application are provided to overcome the above-mentioned shortcomings.

[0013] To achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions:

[0014] In a first aspect, the present invention provides a non-PVC wood-plastic board deformation control device.

[0015] It includes a mold fixedly connected to an extruder for outputting semi-finished plates, and a traction roller assembly composed of a plurality of traction rollers and used for pulling and shaping the semi-finished plates; the mold includes an output port for outputting the semi-finished plates, and there is an angle between the output port and the horizontal plane, so that the direction in which the semi-finished plates are pulled by the traction roller assembly along the output port does not coincide with the direction of the gravity exerted on the semi-finished plates themselves, and the angle between the two is less than 90 degrees.

[0016] In the prior art, sheet substrates made from polyvinyl chloride (e.g., SPC substrates, LVT substrates) typically use polyvinyl chloride as a polymer substrate during the preparation process, and stone powder is added thereto, and the desired sheet is finally obtained through extrusion. Since polyvinyl chloride is an amorphous polymer, its volume shrinkage before and after extrusion is relatively low, so that traditional polyvinyl chloride substrates do not need to be overly concerned about warping caused by its volume shrinkage during the preparation process. At the same time, due to the strong polarity of polyvinyl chloride, the viscosity of the melt obtained after it is mixed and melted with stone powder is relatively high, and the hardness of the semi-finished sheet obtained after the melt flows out of the mold and cools is relatively high, so that its shape-keeping ability is still relatively strong even under the action of external forces, and it is difficult for it to warp and deform under the action of external forces and internal stresses.

[0017] For the reasons described above, the current extrusion process for sheet materials made from polyvinyl chloride (PVC) typically involves the material entering an extruder, undergoing melt plasticization, and then being discharged through a horizontally disposed die to form a semi-finished sheet. The semi-finished sheet is then pulled horizontally and then fed into a cooling mechanism for cooling and shaping. However, with increasing environmental protection requirements, upgrading and replacing PVC materials is urgent. However, while using conventional extrusion equipment to extrude new polyolefin-based sheet materials, the applicant discovered an unexpected technical problem: the polyolefin semi-finished sheet produced using conventional extrusion equipment exhibited significant volume shrinkage and severe warping, making it difficult to use in the production of non-PVC wood-plastic sheet materials and non-PVC wood-plastic flooring.

[0018] In this regard, the applicant has conducted an in-depth study on the above phenomenon and found that the reasons for the serious warping and deformation of non-PVC wood-plastic panels include at least the following: (1) Since the molecular chain segments of polyolefin materials are more regular, their crystallization performance is significantly higher than that of traditional polyvinyl chloride, which causes their volume to shrink during the crystallization process. (2) At the same time, since the viscosity of the polyolefin melt extruded from the mold is lower, it is easily deformed by external forces (traction and gravity). (3) Due to the influence of traction and gravity, the degree of crystallization of the polyolefin material at different positions is uneven, further aggravating the formation of warping. With regard to the above-mentioned reasons for warping, the applicant proposes that improvements can be made from several angles, such as raw material formula, preparation and molding process, and molding equipment.

[0019] Among them, this application is aimed at modifying traditional PVC wood-plastic board forming equipment to adapt to the production of new non-PVC wood-plastic boards, thereby solving or alleviating the serious warping and deformation problem of non-PVC wood-plastic boards caused by the equipment.

[0020] During routine experiments, the applicant discovered that extrusion equipment significantly influences the crystallization behavior of polyolefin-based, non-PVC wood-plastic sheet materials. Based on this, the applicant unexpectedly discovered that after the raw materials are melted and plasticized in the extruder and then extruded from the mold, gravity pulls the melt, causing the center of the semi-finished sheet to sag. Furthermore, the semi-finished sheet is subjected to a horizontal pulling force during transportation. The combined effects of these two forces lead to inconsistent crystallization behavior at the center and edges of the semi-finished sheet, resulting in different crystallinity levels and crystal sizes at the center and edges, ultimately causing warping across the width of the sheet.

[0021] To address this issue, the present application creatively changes the angle between the die outlet and the horizontal plane, thereby changing the angle between the direction in which the semi-finished sheet is pulled by the traction roller assembly along the outlet and the direction of gravity acting on the semi-finished sheet to less than 90 degrees. This arrangement weakens the combined force between the traction force of the traction roller assembly and gravity across the thickness of the semi-finished sheet and makes it more evenly distributed across the width of the sheet, thereby reducing warping of the semi-finished sheet across its width.

[0022] In addition, through the above-mentioned settings, the resultant force of the semi-finished plate along its length direction is also improved, so that the macromolecules or microcrystals and other structures inside the semi-finished plate are significantly oriented along its length direction, further accelerating the induction effect of external force on the semi-finished plate along its length direction, and ultimately improving the crystallization speed and crystallinity of the semi-finished plate, thereby preventing shrinkage and warping caused by changes in its crystal form during subsequent cooling and storage processes.

[0023] Furthermore, since the macromolecules or microcrystals inside the semi-finished board are oriented under the induction of external force, their crystal structures are always evenly arranged along the length direction of the semi-finished board, so the mechanical strength, hardness and wear resistance of the semi-finished board can be greatly improved.

[0024] However, the direction in which the semi-finished plate is pulled by the traction roller assembly along the output port and the direction in which the semi-finished plate is subjected to gravity are not necessarily smaller than the direction in which the semi-finished plate is pulled. For example, in the extreme case where the two overlap, the resultant force on the semi-finished plate along its length direction is greatly increased, resulting in uneven thickness of the semi-finished plate, and the specific surface manifestations are flow lines and wave lines.

[0025] Therefore, in summary, by changing the angular relationship between the die's outlet and the horizontal plane, the present invention alters the angle between the direction in which the semi-finished sheet material is pulled by the traction roller assembly along the outlet and the direction of gravity acting on the semi-finished sheet material. This effectively overcomes the shrinkage and warping issues that occur during the extrusion process of conventional polyvinyl chloride sheet materials. Furthermore, the present invention unexpectedly improves the sheet material's mechanical strength, hardness, and wear resistance.

[0026] Preferably, the traction roller assembly comprises at least an input traction roller pair for traction of the semi-finished plate in an inclined direction of the output port, and an output traction roller pair for transporting the semi-finished plate in a horizontal direction.

[0027] The traction roller assembly in the present application includes multiple traction roller pairs, so the semi-finished plate can be extruded and shaped multiple times during the traction process, thereby micro-regulating the crystallization state inside the semi-finished plate, thereby ensuring that the crystal size structure inside the semi-finished plate can be maintained in a roughly the same state, thereby preventing problems such as warping caused by different crystallization conditions of different parts of the silver.

[0028] Preferably, the angle between a perpendicular line connecting the centers of the two traction rollers in the input traction roller pair and the horizontal plane is greater than the angle between the output port and the horizontal plane.

[0029] The above-mentioned limitations in the present application enable the traction rollers of the input traction roller pair to be closer to perpendicular to the horizontal plane, thereby being able to exert a greater traction force. This helps to more effectively pull the semi-finished sheet materials and provide a stronger pulling force, making the sheet materials more stable during transportation. At the same time, the tilted input traction roller pair can tilt and pull the semi-finished sheet materials in the direction of the output port. This traction method can improve the transmission of the sheet materials, allowing them to pass through the device more smoothly and reduce possible jams or blockages. And because the traction force exerted by the input traction roller pair is greater, it can effectively resist the gravity acting on the semi-finished sheet materials. This can reduce the risk of deformation of the sheet materials during transportation and maintain the stability of the sheet materials' shape. Finally, the tilted input traction roller pair can better control the movement trajectory and speed of the semi-finished sheet materials. This can improve the operating efficiency of the production line and ensure that the semi-finished sheet materials are transported and processed in the expected manner.

[0030] Preferably, the center connecting line of the input traction roller pair intersects with the center connecting line of the output traction roller pair and is not perpendicular.

[0031] In this application, the center connecting lines of the input traction roller pair and the output traction roller pair are intersected and not perpendicular, which can produce the following benefits: (1) The intersecting and non-perpendicular center connecting lines can guide the semi-finished plate to change direction during the traction process. This can improve the transmission path of the plate, allowing it to pass through the device more smoothly and reduce possible jamming or blockage. (2) The intersecting center connecting lines can help to evenly apply the traction force so that it is evenly distributed over the entire surface of the plate. This helps to reduce the risk of deformation of the plate and ensure that the plate remains stable during transportation. (3) Because the center connecting lines intersect and are not perpendicular, the input traction roller pair and the output traction roller pair can work better together to provide stronger tension and traction. This can improve the traction effect and better control the semi-finished plate. (4) The intersecting and non-perpendicular center connecting line design can provide more operational flexibility. The operator can adjust the angle between the input traction roller pair and the output traction roller pair as needed to meet the requirements of different plates.

[0032] Preferably, the input pulling roller pair comprises a pair of pulling rollers distributed in the vertical direction; wherein the height of the output port of the mold is greater than the height of the pulling roller located below the input pulling roller pair.

[0033] By setting the height of the delivery port higher than the traction rollers located below the input traction roller pair, the semi-finished sheets can be ensured to pass smoothly through the traction rollers. This prevents the semi-finished sheets from being stuck or obstructed by the traction rollers during transport, ensuring smooth sheet transport and reducing the possibility of jams or production stoppages. This improves production line capacity and efficiency, while also preventing damage or deformation of the semi-finished sheets during transport, reducing the frequency of maintenance and replacement of the traction rollers. This reduces maintenance costs and extends the service life of the traction rollers. It also prevents the semi-finished sheets from being subjected to excessive pressure and deformation when passing through the traction rollers. This helps maintain the sheet's shape and structural integrity, reducing the risk of damage.

[0034] Preferably, the semi-finished plate output from the output port is pulled and transported along a tangent direction to the input pulling roller.

[0035] Traction of semi-finished sheets along a tangential direction to the input pull rollers achieves smooth movement. This method of traction reduces shaking and jolting during conveyance, ensuring stable sheet transport. It also allows sheets to pass through the device at a higher speed and in a more stable manner, thereby improving production line capacity and efficiency. Furthermore, tangential traction allows for better control of sheet position and positioning. This helps improve sheet processing and positioning accuracy, ensuring that the final product meets quality and dimensional requirements. Furthermore, this method of traction provides uniform traction force, reducing the risk of bending and deformation during conveyance, preventing localized deformation and maintaining sheet flatness and shape stability.

[0036] Preferably, the angle between the output port and the horizontal plane is 30-60°.

[0037] Preferably, the temperature of the pulling roller assembly is lower than the temperature of the output port; and

[0038] The temperatures of the traction rollers in the traction roller assembly are increased sequentially along the conveying direction of the semi-finished plate.

[0039] The present application can control the crystallization behavior of polymers during the transportation of semi-finished sheet materials by setting a temperature gradient. During the process of the material melt being discharged along the output port of the mold, the temperature of the surface of the semi-finished sheet material will drop rapidly, while the middle part will still maintain a higher temperature. Therefore, due to the large temperature difference between the inside and outside of the semi-finished sheet material, the crystallinity inside and outside the semi-finished sheet material will change significantly, which is specifically manifested in that the particle size of the polymer crystals on the surface of the semi-finished sheet material is smaller, while the polymer crystals inside the semi-finished sheet material are relatively larger. At the same time, due to the sudden drop in temperature on the surface of the semi-finished sheet material, a part of the polymer chain segments will be fixed by cold before they have time to crystallize, resulting in changes in the crystallinity of the polymers inside and outside the semi-finished sheet material, which further affects the stability of the semi-finished sheet material.

[0040] In response to the above-mentioned problems, the present application affects the crystallization process of the polymer by setting the temperature of the pulling roller assembly. The applicant has found that by gradually increasing the temperature of the pulling roller assembly, the degree of crystallization inside and outside the semi-finished sheet can be increased, the crystallinity of the polymer can be improved, and precise control of the polymer crystallization process can be achieved, ensuring uniform crystallization during the conveying process, thereby improving the quality and consistency of the product and reducing the non-uniformity of the material. This helps to improve the strength and rigidity of the semi-finished sheet, making it more suitable for specific application requirements. In addition, by gradually increasing the temperature of the pulling rollers in the pulling roller assembly, the semi-finished sheet can be subjected to an annealing step, thereby reducing the residual stress in the semi-finished sheet. The principle is that the change in temperature can cause the polymer molecules to rearrange, reduce the residual stress in the sheet, and improve the stability and durability of the sheet.

[0041] In summary, setting the temperature of the pulling roller assembly lower than the temperature of the output port and gradually increasing the temperature of the pulling roller along the conveying direction of the semi-finished sheet can improve the strength of the semi-finished sheet, reduce residual stress, and improve the quality and consistency of the product by controlling the crystallization behavior of the polymer.

[0042] Preferably, the temperature difference between the traction roller for inputting the semi-finished plate and the temperature of the output port in the traction roller assembly is 10-15°C;

[0043] The difference between the temperature of the traction roller for outputting the semi-finished plate in the traction roller assembly and the temperature of the output port is ≤10°C.

[0044] In the present application, the temperature of the traction roller of the traction roller assembly is close to the temperature of the semi-finished plate output from the output port, which can effectively avoid the uneven crystallization caused by the rapid cooling of the semi-finished plate, thereby further improving the stability of the semi-finished plate and reducing its warping rate.

[0045] Preferably, the traction roller comprises a traction roller body and a first temperature-controlled jacket covering the outside of the traction roller body;

[0046] The first temperature-controlling jacket is filled with a temperature-controlling liquid capable of controlling the surface temperature of the first temperature-controlling jacket.

[0047] The present application designs a traction roller to include a traction roller body and a first temperature-controlled jacket on the outside, and fills it with a temperature-controlled liquid that can control the surface temperature of the jacket. The temperature of the traction roller can be precisely controlled and optimized through temperature control, temperature uniformity, heat regulation, and adhesion prevention.

[0048] Preferably, the mold is provided with a temperature control device located outside the output port for controlling the temperature of the semi-finished plate output from the output port.

[0049] Preferably, the temperature control device includes a second temperature control jacket, and the interior of the second temperature control jacket is filled with temperature control liquid.

[0050] Preferably, the deformation control device further comprises a bearing seat for bearing the traction roller assembly;

[0051] The bearing seat is also provided with a driving device for driving the traction roller in the traction roller assembly to move.

[0052] The bearing base provides the necessary support and stability for the pulling roller assembly. It bears the weight of the entire pulling roller assembly and ensures its balance and stability during operation. Furthermore, the drive mechanism precisely controls the movement of the pulling roller. This enables precise pulling and positioning of the semi-finished sheet material, ensuring the accuracy of the product's size and shape.

[0053] Preferably, a shaping template for shaping the semi-finished plate is further provided on the bearing seat behind the traction roller assembly.

[0054] Forming templates provide precise, standardized shapes and dimensions. By placing the semi-finished sheet material in contact with the forming template and applying appropriate pressure and heat, the semi-finished sheet material is ensured to conform to the desired shape and dimensions during the forming process, improving product precision. Furthermore, the use of forming templates reduces deviations in the final shape caused by inconsistent manual operation, improving product consistency and stability, and increasing production efficiency.

[0055] Preferably, the deformation control device further comprises a mold hanger for hoisting and fixing the mold.

[0056] Mold hangers provide a safe and reliable method for hoisting and securing molds. They ensure mold stability during hoisting and transportation, preventing accidental shaking or falling, and protecting the equipment and operators. They also simplify the mold hoisting and securing process, improving hoisting efficiency and accuracy.

[0057] In a second aspect, the present invention further provides a non-PVC wood-plastic board extrusion production line, which comprises the non-PVC wood-plastic board deformation control device as described in any one of the above.

[0058] Preferably, the non-PVC wood-plastic board extrusion production line is provided with an extruder, a deformation control device, a cooling mechanism, a traction mechanism and a cutting mechanism in sequence along the material transmission direction.

[0059] In this application, the extruder is the initial part of the production line, used to heat, melt, and extrude the non-PVC wood-plastic composite material into a board shape. A deformation control device is located after the extruder and is used to control the deformation of the extruded board, thereby reducing the problem of warping after extrusion. The cooling mechanism is used to quickly cool and solidify the extruded board to maintain the desired shape and size. The traction mechanism is located after the cooling mechanism and is used to pull and stretch the cooled board to increase its strength and stability. The cutting mechanism is located after the traction mechanism and is used to cut the cooled and pulled board into the desired length to obtain the final non-PVC wood-plastic board product.

[0060] Through the above production line configuration, the extrusion production of non-PVC wood-plastic boards can be realized, wherein the function of the deformation control device is to control the deformation of the extruded board to obtain the desired shape and size.

[0061] Preferably, the cooling device includes several groups of powered cooling rollers and several groups of driven cooling rollers.

[0062] A cooling system with powered and driven cooling rollers can improve production efficiency. Rapid cooling and deformation control accelerate the cooling of extruded sheet, shortening production cycles. Uniform cooling and shape control also reduce defective product rates caused by uneven temperature or deformation, improving product quality and production capacity.

[0063] Preferably, the cooling device further comprises a cooling bracket arranged behind the powered cooling roller and the driven cooling roller.

[0064] Preferably, the bottom of the deformation control device and the cooling mechanism is provided with a slide rail arranged along the extension direction of the extruder;

[0065] The bottom of the deformation control device and the cooling mechanism is also provided with a pulley which can drive the deformation control device and the cooling mechanism to move along the slide rail to control the distance between the deformation control device and the cooling mechanism and the mold.

[0066] The design of the slide rails and pulleys enables flexible adjustment of the deformation control device and cooling mechanism. By adjusting the pulley position, the operator can control the distance between the deformation control device and cooling mechanism and the mold to accommodate molds of varying sizes and shapes. Furthermore, by adjusting the pulley position, the gap between the deformation control device and cooling mechanism and the mold can be fine-tuned to achieve the desired deformation and cooling effects. Furthermore, the design of the slide rails and pulleys facilitates adjustment and maintenance of the deformation control device and cooling mechanism. Operators can easily move the deformation control device and cooling mechanism for cleaning, repair, or component replacement. This reduces downtime and improves production line stability and reliability. Finally, by quickly adjusting the distance between the deformation control device and cooling mechanism and the mold, mold change and adjustment time can be shortened, reducing production line downtime and improving production efficiency and capacity.

[0067] In a third aspect, the present invention also provides the use of the above-mentioned non-PVC wood-plastic board deformation control device or a non-PVC wood-plastic board extrusion production line comprising the deformation control device in the preparation of non-PVC wood-plastic boards or non-PVC floors.

[0068] The present invention has the following beneficial effects:

[0069] - The non-PVC wood-plastic board deformation control device in this application changes the angle between the output port of the mold and the horizontal plane, thereby changing the angle between the direction in which the semi-finished board is pulled by the traction roller assembly along the output port and the direction of the gravity exerted on the semi-finished board itself, effectively overcoming the shrinkage and warping problems that do not occur in the traditional board substrate made of PVC as raw material during the extrusion process;

[0070] -At the same time, the above arrangement also unexpectedly improves the mechanical strength, hardness and wear resistance of the plate;

[0071] - In this application, by adding the non-PVC wood-plastic board deformation control device to the non-PVC wood-plastic board extrusion production line, the unqualified flooring caused by the warping of the board is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] FIG1 is a schematic structural diagram of the non-PVC wood-plastic board extrusion production line described in the present invention.

[0073] FIG2 is an enlarged view of point a in FIG1 of the present invention.

[0074] FIG3 is a schematic diagram of the hoisting structure of the mold of the present invention.

[0075] FIG4 is a schematic structural diagram of the traction roller assembly of the present invention.

[0076] FIG5 is a schematic diagram of the cross-sectional structure of the traction roller of the present invention.

[0077] FIG6 is a schematic diagram of the cross-sectional structure of the mold of the present invention.

[0078] FIG7 is a schematic structural diagram of a mold temperature controller in the cooling mechanism of the present invention.

[0079] Wherein: extruder 100, barrel 101, feeding mechanism 102, semi-finished plate 200, mold 300, output port 301, temperature control device 302, second temperature control jacket 303, mold hanger 304, traction roller assembly 400, traction roller 401, No. 1 traction roller 401-1, No. 2 traction roller 401-2, No. 3 traction roller 401-3, input traction roller pair 402, output traction roller pair 403, traction roller body 404, first temperature control jacket 405, bearing seat 406, driving device 407, shaping template 408, cooling mechanism 500, mold temperature controller 501, powered cooling roller 502, driven cooling roller 503, cooling bracket 504, slide rail 505, pulley 506, traction mechanism 600, cutting mechanism 700. DETAILED DESCRIPTION

[0080] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below generally represent only a portion of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0081] As shown in Figure 1, this embodiment 1 provides a non-polyvinyl chloride wood-plastic board extrusion production line. In the material transmission direction (i.e., from left to right in Figure 1), the extrusion production line sequentially includes an extruder 100 for melting and plasticizing the non-polyvinyl chloride material and extruding the plasticized melt, and a mold 300 for outputting the plasticized melt to form a semi-finished board 200, a traction roller assembly 400 for pulling the semi-finished board 200 and controlling its deformation rate, a cooling mechanism 500 for cooling and shaping the semi-finished board 200 after deformation control, a traction mechanism 600 for traction of the semi-finished board 200, and a cutting mechanism 700 for cutting the semi-finished board 200 to obtain a finished non-polyvinyl chloride wood-plastic board.

[0082] The extruder 100 is a single-screw extruder or a twin-screw extruder, comprising a barrel 101 and a feed mechanism 102 for feeding material into the barrel 101. Taking the production of polypropylene wood-plastic board material as an example, polypropylene wood-plastic board material raw materials are first fed into the feed mechanism 102. These polypropylene wood-plastic board material raw materials are heated by the barrel 101 and plasticized by the screws inside, thereby melting to form a melt. Polypropylene wood-plastic board material raw materials typically include polypropylene resin and wood powder, and in some cases, a certain amount of plasticizer and lubricant. These raw materials are then mixed and crushed through an extrusion granulation device or a mixer to obtain the desired polypropylene wood-plastic board material.

[0083] As shown in Figures 2 and 3, the mold 300 is connected to the end of the barrel 101 and includes an outlet 301. The melt flowing out of the barrel 101 is extruded and shaped through the outlet 301 to obtain a semi-finished sheet material 200. Unlike conventional polyvinyl chloride sheet substrates, such as SPC substrates and LVT substrates, the mold 300 in this application is at a certain angle to the horizontal plane. This causes the semi-finished sheet material 200 to be discharged from the mold 300 in a non-horizontal direction, thereby reducing the increase in the warpage of the semi-finished sheet material 200 caused by gravity.

[0084] Due to the high mass of the mold 300, in some preferred embodiments, a mold hanger 304 is added to enhance the stability of the connection between the mold 300 and the barrel 101. This provides a safe and reliable method for hoisting and securing the mold 300. This ensures the stability of the mold 300 during hoisting and transportation, preventing accidental shaking or falling, and protecting the equipment and operators. It also simplifies the mold hoisting and securing process, improving hoisting efficiency and accuracy.

[0085] As shown in Figures 2 and 4 , in this embodiment, a pulling roller assembly 400 is provided behind the mold 300 to pull and shape the semi-finished sheet material 200. The pulling roller assembly 400 is composed of a plurality of pulling rollers 401. As shown in Figure 2 , there are three pulling rollers 401 in this embodiment. Along the conveying direction of the semi-finished sheet material, the three pulling rollers 401 can be divided into a pulling roller No. 1 401-1, a pulling roller No. 2 401-2, and a pulling roller No. 3 401-3. According to the position and function of the traction roller 401, the traction roller 401 in the traction roller assembly 400 can be divided into at least an input traction roller pair 402 composed of traction roller No. 1 401-1 and traction roller No. 2 401-2, which is used to pull the semi-finished plate 200 in an inclined direction along the output port 301, and an output traction roller pair 403 composed of traction roller No. 2 401-2 and traction roller No. 3 401-3, which is used to change the conveying direction of the semi-finished plate 200 so that it is conveyed in a horizontal direction.

[0086] In some preferred embodiments, the center connection line of the No. 1 traction roller 401-1 and the No. 2 traction roller 401-2 in the input traction roller pair 402 intersects and is not perpendicular to the center connection line of the No. 2 traction roller 401-2 and the No. 3 traction roller 401-3 in the output traction roller pair 403, so that the No. 2 traction roller 401-2 and the No. 3 traction roller 401-3 are flat in the horizontal direction, while the No. 1 traction roller 401-1 and the No. 2 traction roller 401-2 are obliquely distributed in the vertical direction, wherein the No. 1 traction roller 401-1 is closer to the output port 301 of the mold 300 than the No. 2 traction roller 401-2. In addition, the height of the output port 301 of the mold 300 is greater than the height of the No. 1 traction roller 401-1 and less than the height of the No. 2 traction roller 401-2, so that the semi-finished plate output from the output port 301 is pulled and transported in a direction tangent to both the No. 1 traction roller 401-1 and the No. 2 traction roller 401-2 along 200.

[0087] In some preferred embodiments, the angle between the perpendicular line of the center connection line of traction roller No. 1 401-1 and traction roller No. 2 401-2 in the input traction roller pair 402 and the horizontal plane is greater than the angle between the output port 301 and the horizontal plane. Such an arrangement can further reduce the warping of the prepared semi-finished plate 200.

[0088] In order to explore the relationship between the angle between the output port 301 and the horizontal plane and the warping degree of the semi-finished plate 200 finally obtained, in this embodiment, the semi-finished plate 200 prepared with different output port 301 angles and the pulling roller assembly 400 adapted to the different output port 301 angles were tested, and the test results are shown in Table 1 below.

[0089] Table 1

[0090] The test results above show that changing the angle of the outlet 301 effectively reduces the effect of gravity on the warpage of the semi-finished sheet material 200. When the outlet 301 is level with the horizontal plane (i.e., at an angle of 0°), the semi-finished sheet material exhibits the greatest warpage, reaching 0.62 mm / m. As the angle between the outlet 301 and the horizontal plane increases, the warpage gradually decreases. When the angle between the outlet 301 and the horizontal plane is ≥30°, the warpage of the semi-finished sheet material 200 can reach a level of less than 0.3 mm / m. However, a larger angle between the outlet 301 and the horizontal plane is not necessarily better. When the angle between the outlet 301 and the horizontal plane is 80°, flow lines appear on the surface of the semi-finished sheet material 200. When the outlet 301 is perpendicular to the horizontal plane (i.e., at an angle of 90°), significant flow lines are present. Therefore, considering the warping and flow pattern of the semi-finished plate 200, when the angle between the output port 301 and the horizontal plane is 30-60°, the prepared semi-finished plate 200 has the best performance.

[0091] In addition to the angle between the outlet 301 and the horizontal plane regulating the warping of the semi-finished sheet 200, the applicant has also discovered that the temperature of each pulling roller 401 in the pulling roller assembly plays an auxiliary role in controlling the deformation of the semi-finished sheet 200. The applicant has discovered that after the semi-finished sheet 200 is discharged from the outlet 301, its surface temperature drops rapidly, while the center portion remains at a higher temperature. Therefore, due to the large temperature difference between the inside and outside of the semi-finished sheet 200, the crystallization properties inside and outside the semi-finished sheet 200 will be significantly changed. Specifically, the particle size of the polymer crystals on the surface of the semi-finished sheet 200 is smaller, while the polymer crystals inside the semi-finished sheet are relatively larger. In addition, the sudden drop in temperature on the surface of the semi-finished sheet 200 causes some polymer chains to be cooled and fixed before they have time to crystallize, resulting in changes in the crystallinity of the polymer inside and outside the semi-finished sheet 200, further affecting the stability of the semi-finished sheet 200.

[0092] In this embodiment, the temperature of the pulling roller assembly 400 is adjusted to address the aforementioned issues, thereby altering the polymer crystallization process and reducing warping and deformation of the semi-finished sheet 200 after extrusion. Specifically, the temperature of the pulling roller assembly 400 is set lower than the temperature of the outlet 301, thereby promoting polymer crystallization within the semi-finished sheet 200. Simultaneously, the temperature of the pulling rollers 401 in the pulling roller assembly 400 increases sequentially along the conveying direction of the semi-finished sheet 200. The gradually increasing temperature of the pulling roller assembly 400 increases the degree of crystallization within and outside the semi-finished sheet 200, improving the polymer's crystallinity. This allows for precise control of the polymer crystallization process, ensuring uniform crystallization during conveyance, thereby improving the quality and consistency of the finished product and reducing material non-uniformity. This helps increase the strength and stiffness of the semi-finished sheet 200, making it more suitable for specific application requirements. Furthermore, by gradually increasing the temperature of the pulling rollers 401 in the pulling roller assembly 400, the semi-finished sheet 200 can be annealed, thereby reducing residual stress within the semi-finished sheet 200. The principle is that changes in temperature can cause polymer molecules to rearrange, reduce residual stress in the board, and improve the stability and durability of the board.

[0093] In some preferred conditions of this embodiment, the temperature difference between the pulling roller 401 in the pulling roller assembly 400 for inputting the semi-finished sheet material 200 and the temperature of the outlet 301 can be 10-15°C, while the temperature difference between the pulling roller 401 in the pulling roller assembly 400 for outputting the semi-finished sheet material 200 and the temperature of the outlet 301 can be ≤10°C. This setting can ensure that the temperature of the pulling roller 401 in the pulling roller assembly 400 is closer to the temperature of the semi-finished sheet material 200 output from the outlet 301, effectively avoiding the phenomenon of uneven crystallization caused by rapid cooling of the semi-finished sheet material 200, thereby further improving the stability of the semi-finished sheet material 200 and reducing its warpage.

[0094] In order to explore the relationship between the temperature of the pulling roller assembly 400 and the warpage of the final semi-finished plate 200, the semi-finished plate 200 prepared at different pulling roller assembly 400 temperatures were tested in this embodiment, and the test results are shown in Table 2 below.

[0095] Table 2

[0096] It can be seen from the above test results that as the temperature of each pulling roller 401 in the pulling roller assembly 400 changes, the warping of the semi-finished plate 200 obtained in the end will also be adjusted accordingly.

[0097] In order to precisely control the temperature of the pulling roller 401 and the output port 300 in the pulling roller assembly 400 , the present application specifically designs the pulling roller 401 and the mold 300 .

[0098] In some preferred embodiments, as shown in Figure 5, the traction roller 401 includes a traction roller body 404 and a first temperature-controlled jacket 405 covering the outside of the traction roller body 404, and the area between the first temperature-controlled jacket 405 and the traction roller body 404 is filled with a temperature-controlled liquid that can control the surface temperature of the first temperature-controlled jacket 405.

[0099] As shown in Figure 6, the mold 300 is provided with a temperature control device 302 located on the outside of the output port 301 for controlling the temperature of the semi-finished plate 200 output from the output port 301. The temperature control device 302 includes a second temperature control jacket 303, and the interior of the second temperature control jacket 303 is filled with temperature control liquid.

[0100] Continuing with Figures 1 and 2, in order to improve the support and stability required by the traction roller assembly 400, this embodiment also includes a bearing seat 406 for supporting the traction roller assembly 400, and the bearing seat 406 is also provided with a driving device 407 for driving the traction roller 401 in the traction roller assembly 400 to move. The driving device 407 can be a motor or other device for providing rotational power to the traction roller 401. Each traction roller 401 can be provided with a corresponding driving device 407, or a plurality of traction rollers 401 can be provided with a corresponding driving device 407, and the linkage of the plurality of traction rollers 401 can be achieved through a transmission device (such as a transmission belt or a transmission chain).

[0101] In addition, to further enhance the stability of the semi-finished sheet material 200, this embodiment further includes a shaping template 408 disposed on the support base 406 behind the traction roller assembly 400 for shaping the semi-finished sheet material 200. The shaping template 408 contacts the semi-finished sheet material 200 and applies a certain amount of pressure and heat, thereby exerting a certain amount of heat pressure on the semi-finished sheet material. This ensures that the semi-finished sheet material is formed into the desired shape and size according to design requirements during the shaping process, thereby improving the shaping accuracy of the product.

[0102] The cooling mechanism 500 includes a mold temperature controller 501 with rollers, and its structural schematic diagram is shown in Figure 7. The mold temperature controller 501 includes several groups of powered cooling rollers 502 and several groups of driven cooling rollers 503. When the semi-finished plate 200 comes out of the shaping template 408, it is transported forward along the powered cooling rollers 502 and the driven cooling rollers 503 in turn, so that the powered cooling rollers 502 and the driven cooling rollers 503 come into contact with the semi-finished plate 200, thereby quickly cooling and shaping it.

[0103] As shown in FIG1 , after the semi-finished plate 200 comes out of the mold temperature controller 501 , it enters a cooling bracket 504 . As the semi-finished plate 200 moves on the cooling bracket 504 , the semi-finished plate 200 comes into contact with the air, thereby being cooled.

[0104] In some preferred embodiments, to facilitate adjustment of the distance between the pulling roller assembly 400, the cooling mechanism 500, and the die 300, the applicant has provided a slide rail 505 at the bottom of the pulling roller assembly 400 and the cooling mechanism 500, extending along the direction of the extruder 100. Furthermore, in conjunction with the slide rail 505, a pulley 506 is provided at the bottom of the pulling roller assembly 400 and the cooling mechanism 500, which can drive the pulling roller assembly 400 and the cooling mechanism 500 along the slide rail 505 to control the distance between the pulling roller assembly 400 and the cooling mechanism 500 and the die 300. Thus, by adjusting the position of the pulley 506 on the slide rail 505, the operator can control the distance between the pulling roller assembly 400 and the cooling mechanism 500 and the die 300 to accommodate molds 300 of different sizes and shapes. Furthermore, by adjusting the position of the pulley 506, the gap between the pulling roller assembly 400 and the cooling mechanism 500 and the die can be fine-tuned to achieve the desired deformation and cooling effects.

[0105] In order to reliably pull the semi-finished board 200, a pulling mechanism 600 driven by a motor or other driving mechanism is further provided behind the cooling bracket 504, so that the semi-finished board 200 is input into the cutting mechanism 700 located behind the pulling mechanism 600, thereby realizing the cutting of the semi-finished board 200 and finally obtaining the finished non-PVC wood-plastic board.

[0106] By changing the angle between the die outlet 301 and the horizontal plane, the present invention alters the angle between the direction in which the semi-finished board 200 is pulled by the traction roller assembly 400 along the die outlet 301 and the direction of gravity acting on the semi-finished board 200. This effectively overcomes the shrinkage and warping issues that occur during the extrusion process of conventional PVC-based board substrates. This also unexpectedly improves the board's mechanical strength, hardness, and wear resistance. Furthermore, by adding the non-PVC WPC board deformation control device to the non-PVC WPC board extrusion line, the present invention avoids an increase in the flooring rejection rate due to board warping.

[0107] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A deformation control device for non-polyvinyl chloride wood-plastic board, characterized in that: It comprises a mould fixedly connected to an extruder for outputting a semi-finished plate, and a traction roller assembly composed of a plurality of traction rollers and used for traction and shaping the semi-finished plate; the mould comprises an output port for outputting the semi-finished plate, and there is an angle between the output port and a horizontal plane, so that the direction in which the semi-finished plate is pulled by the traction roller assembly along the output port does not coincide with the direction of the gravity exerted on the semi-finished plate itself, and the angle between the two is less than 90 degrees.

2. A non-PVC wood-plastic board deformation control device according to claim 1, characterized in that: The traction roller assembly at least comprises an input traction roller pair for traction of the semi-finished plate in an inclined direction of the output port, and an output traction roller pair for transporting the semi-finished plate in a horizontal direction.

3. A deformation control device for non-PVC wood-plastic board according to claim 2, characterized in that: The angle between a perpendicular line of a center connecting line of two traction rollers in the input traction roller pair and a horizontal plane is greater than the angle between the output port and the horizontal plane.

4. A non-PVC wood-plastic board deformation control device according to claim 2, characterized in that: The center connecting line of the input traction roller pair intersects with the center connecting line of the output traction roller pair and is not perpendicular.

5. A non-PVC wood-plastic board deformation control device according to claim 2, 3 or 4, characterized in that: The input traction roller pair comprises a pair of traction rollers distributed in the vertical direction; wherein, The height of the output port of the die is greater than the height of the pulling rollers located below the input pulling roller pair.

6. A non-PVC wood-plastic board deformation control device according to any one of claims 1 to 4, characterized in that: The semi-finished plate output from the output port is pulled and transported along a tangent direction to the input pulling roller.

7. The deformation control device for non-PVC wood-plastic board according to claim 1, characterized in that: The angle between the output port and the horizontal plane is 30-60°.

8. The deformation control device for non-PVC wood-plastic board according to claim 1, characterized in that: The temperature of the pulling roller assembly is lower than the temperature of the output port; and The temperatures of the traction rollers in the traction roller assembly are increased sequentially along the conveying direction of the semi-finished plate.

9. A deformation control device for non-PVC wood-plastic board according to claim 8, characterized in that: The temperature difference between the traction roller used to input the semi-finished plate in the traction roller assembly and the temperature of the output port is 10-15°C; the temperature difference between the traction roller used to output the semi-finished plate in the traction roller assembly and the temperature of the output port is ≤10°C.

10. A non-PVC wood-plastic board deformation control device according to claim 1, 8 or 9, characterized in that: The traction roller comprises a traction roller body and a first temperature-controlled jacket covering the outside of the traction roller body; The first temperature-controlling jacket is filled with a temperature-controlling liquid which can control the surface temperature of the first temperature-controlling jacket.

11. A non-PVC wood-plastic board deformation control device according to claim 1, 8 or 9, characterized in that: The mold is provided with a temperature control device located outside the output port for controlling the temperature of the semi-finished plate output from the output port.

12. A deformation control device for non-PVC wood-plastic board according to claim 11, characterized in that: The temperature control device comprises a second temperature control jacket, and the interior of the second temperature control jacket is filled with temperature control liquid.

13. The deformation control device for non-PVC wood-plastic board according to claim 1, characterized in that: The deformation control device also includes a bearing seat for bearing the traction roller assembly; The bearing seat is also provided with a driving device for driving the traction roller in the traction roller assembly to move.

14. A deformation control device for non-PVC wood-plastic board according to claim 13, characterized in that: A shaping template for shaping the semi-finished plate is also arranged on the bearing seat behind the traction roller assembly.

15. A deformation control device for non-PVC wood-plastic board according to claim 1 or 13, characterized in that: The deformation control device also includes a mold hanger for hanging and fixing the mold.

16. A non-polyvinyl chloride wood-plastic board extrusion production line, characterized in that: It comprises the deformation control device of the non-polyvinyl chloride wood-plastic board as described in any one of claims 1 to 15.

17. A non-PVC wood-plastic board extrusion production line according to claim 16, characterized in that: The invention comprises an extruder, a deformation control device, a cooling mechanism, a traction mechanism and a cutting mechanism which are sequentially arranged along the material transmission direction.

18. The non-PVC wood-plastic board extrusion production line according to claim 17, characterized in that: The cooling device comprises a plurality of groups of powered cooling rollers and a plurality of groups of driven cooling rollers.

19. The non-PVC wood-plastic board extrusion production line according to claim 18, characterized in that: The cooling device also includes a cooling bracket arranged behind the powered cooling roller and the driven cooling roller.

20. A non-PVC wood-plastic board extrusion production line according to claim 17, 18 or 19, characterized in that: The bottom of the deformation control device and the cooling mechanism is provided with a slide rail arranged along the extension direction of the extruder; The bottom of the deformation control device and the cooling mechanism is also provided with a pulley which can drive the deformation control device and the cooling mechanism to move along the slide rail to control the distance between the deformation control device and the cooling mechanism and the mold.

21. Use of the non-PVC wood-plastic board deformation control device according to any one of claims 1 to 15 or the non-PVC wood-plastic board extrusion production line comprising the deformation control device according to any one of claims 16 to 20 in the preparation of non-PVC wood-plastic boards or non-PVC floors.

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