Preparation process of steel-plastic co-extrusion type composite outdoor floor

Abstract

The invention discloses a preparation process of a steel-plastic co-extrusion type composite outdoor floor, and belongs to the field of composite floor production. A cold bending process and a coating co-extrusion process of a polymer composite material are combined, and compared with an existing aluminum-plastic co-extrusion aluminum lining extrusion molding process, different continuous cold bending processes are adopted for molding a lining, so that the production efficiency is greatly improved. Therefore, a thinner base material can be adopted, the energy consumption in the production process is lower, and the comprehensive cost is lower; compared with a plastic-wood co-extrusion process popularized in the market, the product has higher mechanical property, cannot be broken like the product of the plastic-wood co-extrusion process even if the product is bent and deformed under high-pressure impact, and is safer and more reliable; and after co-extrusion molding, anti-warping cooling shaping is carried out, so that product warping deformation caused by shrinkage of a high polymer material is effectively avoided, and the flatness of the product is kept.

Description

Technical Field

[0001] This invention relates to the field of composite flooring production, and in particular to a preparation process for steel-plastic co-extruded composite outdoor flooring. Background Technology

[0002] The existing production process for wood-plastic co-extruded composite outdoor flooring is as follows: Using recycled polyolefin resin as a carrier and wood fiber as a filler, the mixture is mixed and dehumidified before being produced using a conical twin-screw plastic extruder with an extrusion die (the die consists of two parts: a rear section for extruding the wood-plastic composite material and a front section for co-extrusion). Simultaneously, a single-screw plastic extruder extrudes molten polyolefin modified material into the co-extrusion section of the die, and co-extrudes it onto the wood-plastic composite material that passes through the co-extrusion die. After the co-extrusion process is completed, the product undergoes online hot pressing, natural cooling, and length cutting to become the finished product. The natural wood fibers in wood-plastic composites readily absorb moisture from the natural environment, leading to expansion, cracking, deformation, and mold growth in the wood-plastic substrate. Currently, due to limitations in technology, this is difficult to completely avoid. In addition, wood-plastic composites contain more than 60% natural wood fibers. The high content of wood fiber filler reduces production costs but also reduces the bending strength of wood-plastic composites. Currently, the bending strength of wood-plastic composites is generally maintained at around 20 MPa (according to GB / T24508-2020). In public places with dense crowds and high mobility, this bending strength standard poses a significant safety hazard. There are also aluminum plates used as the base material for processing aluminum-plastic composite outdoor flooring on the market, but aluminum is expensive, more than four times the cost of conventional steel. The high cost not only consumes a lot of resources, but also keeps the product price high, making it difficult to become a mass consumer product. In addition, when co-extruded with polyolefin modified resin, in order to maintain the bending strength of the product, ensure the flatness of the product, and prevent the shrinkage and deformation of the plastic after co-extrusion from affecting the overall appearance of the product, the cross-sectional thickness of the rectangular aluminum substrate needs to reach more than 1.2mm. The amount of material used is far greater than that of the high-strength substrate, which is the main reason for its high cost. Summary of the Invention

[0003] This invention provides a manufacturing process for steel-plastic co-extruded composite outdoor flooring, which can at least solve one of the problems mentioned in the background art.

[0004] A manufacturing process for a steel-plastic co-extruded composite outdoor flooring includes the following steps: The process includes the following steps: cooling and shaping the co-extruded steel-plastic profile. During the cooling process, pressure is applied to different positions of the profile from above and below to complete the shaping.

[0005] In co-extrusion molding, the substrate is fed into the co-extrusion die, and at the same time, molten thermoplastic raw material is extruded into the co-extrusion die and completely or partially covers the substrate that passes through the co-extrusion die simultaneously.

[0006] The substrate before co-extrusion molding is treated as follows: Sheet / roll / plate / strip substrates are cold-bent multiple times to form plate-like or frame-like structures, with the upper and lower sides of the frame-like structure having at least one contact surface.

[0007] After the substrate is cold-bent, it is welded and shaped.

[0008] At least one of the upper and lower sides of the frame structure is a continuous surface; preferably, one is a continuous surface and the other is a discontinuous surface.

[0009] The cross-section of the frame structure is M-shaped or Great Wall-shaped.

[0010] The length of the contact surface in the width direction of the frame structure is not less than the thickness of the sheet substrate.

[0011] During the welding shaping process, multiple points on the substrate are welded, including at least the substrate joint and any point on the upper side area of ​​the substrate corresponding to the contact surface.

[0012] During the welding and shaping process, five points on the substrate are welded. These five points include the substrate joint and two points on each of the two upper side areas that correspond one-to-one with the two contact surfaces of the substrate.

[0013] During the cooling process of the profile, pressure is applied to the sides and middle of the plate from the top and bottom of the profile to complete the shaping.

[0014] The substrate is made of galvanized steel sheet or zinc-aluminum-magnesium steel sheet.

[0015] The thermoplastic raw material includes at least one of the following: modified polyolefin resin, ABS, saline resin, and TPE, or a combination of multiple of the above materials.

[0016] During co-extrusion molding, one or more of the following are added to the thermoplastic raw materials: wear-resistant and aging-resistant additives, flame retardants, antioxidants, ultraviolet absorbers, and fluorescent powders.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention combines the cold bending process with the co-extrusion process of polymer composite materials. Compared with the existing aluminum-plastic co-extrusion aluminum liner extrusion molding process, the liner is formed by a different continuous cold bending process. Therefore, a thinner substrate can be used, the energy consumption in the production process is lower, and the overall cost is also lower. Compared with the wood-plastic co-extrusion process that is popular in the market, its products have higher mechanical properties. Even if bending deformation occurs under high pressure impact, it will not break like the products of wood-plastic co-extrusion process, making it safer and more reliable. In addition, after co-extrusion molding, anti-warping cooling and shaping are carried out to effectively avoid product warping and deformation caused by the shrinkage of polymer materials and maintain the flatness of the product. Attached Figure Description

[0018] Figure 1 This is a process flow diagram for the preparation of the steel-plastic co-extruded composite outdoor flooring in Example 2; Figure 2 This is a schematic diagram of the welding points of the cold-bent substrate. Figure 3 This is a schematic diagram of various frame-like structures after cold bending. Figure 4 This is a process flow diagram for the preparation of the steel-plastic co-extruded composite outdoor flooring in Example 3.

[0019] Explanation of reference numerals in the attached figures: 1-Welding point one, 2-Welding point two. Detailed Implementation

[0020] The following detailed description of a specific embodiment of the present invention is provided in conjunction with the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.

[0021] After aluminum-plastic co-extrusion and steel-plastic co-extrusion, due to the different cooling rates of the substrate and the plastic, the shrinkage and deformation of the plastic will cause the sides of the co-extruded profile to warp, making the product unable to be installed and used normally. Based on this, this application proposes the following embodiment to solve this problem.

[0022] Example 1 The manufacturing process of a steel-plastic co-extruded composite outdoor flooring provided in this embodiment of the invention shall include at least the following steps: The co-extruded steel-plastic profile is cooled and shaped. During the cooling process, pressure is applied to different positions of the steel-plastic profile from the top and bottom to complete the shaping. The specific locations of the board material here are: the two sides where the board material warps and the apex of the arc formed by the warping; During the conveying of the sheet material, applying pressure to the top of the arc from above or below can cause the warped sides of the sheet material to be suspended in the air. At the same time, applying pressure to the sides that may warp later can achieve anti-warping. Meanwhile, the sheet material is cooled by a cooling device to shorten the difference between the cooling rate of the substrate and the cooling rate of the plastic, further reducing warping. In some other embodiments, the cross-section of the selected pressure-applying structural member can be circular, which allows for continuous pressure application during sheet material transport and reduces damage to the sheet material. Multiple cooling devices and devices for applying anti-warping pressure should be arranged along the conveying direction of the sheet material to improve the anti-warping effect; By combining the aforementioned physical application of anti-warping force with accelerated cooling, the degree of warping can be suppressed within an acceptable range, effectively improving the yield rate.

[0023] Example 2 Because the aluminum substrate used in existing aluminum-based outdoor flooring is quite thick, the material cost and manufacturing energy consumption cost are too high. Therefore, this embodiment aims to reduce production costs and improve safety. The present invention provides a manufacturing process for a steel-plastic co-extruded composite outdoor flooring. Based on the above-described embodiment one, the substrate before co-extrusion molding is treated as follows: The substrate is cold-bent multiple times to form a plate-like or frame-like structure. This embodiment takes a frame-like structure as an example, and its shape is as follows: Figure 2 and Figure 3 In this embodiment, the substrate is selected as sheet / roll / plate / strip substrate, which is thinner than the existing aluminum substrate. The overall thickness of the frame structure formed can be similar to or thicker than the existing aluminum substrate. Those skilled in the art can make adaptive adjustments according to the required compressive strength. Using sheet-like substrates to form a frame structure as the substrate can reduce the overall weight compared to directly using sheet metal as the substrate. Compared to aluminum of the same size, it has higher strength. Compared to aluminum of the same strength, it is cheaper and thinner. Compared to wood substrates, it has better strength and fire resistance. In some other embodiments, the substrate is cold-bent and spliced ​​(e.g., welded, riveted, stamped) to form a frame structure; To increase strength, in some other embodiments, the upper and lower sides of the frame structure have at least one contact surface, and the length of the contact surface in the width direction of the frame structure is not less than the thickness of the sheet substrate. The cross-section of the frame structure can be M-shaped or Great Wall-shaped, as shown in Figure 2. This embodiment takes the Great Wall-shaped structure as an example. Those skilled in the art can also adapt the shape according to actual needs. Since the upper and lower sides have at least one contact surface, one of the upper and lower sides of the sheet formed after co-extrusion is a continuous surface and the other is a discontinuous surface. After co-extrusion, the continuous surface warps due to the shrinkage of the plastic, while the discontinuous surface is not affected. Based on this, the process of the above-mentioned Example 1 is used to further solve the warping problem. In some other embodiments, such as Figure 3 As shown, the two sides of the upper and lower sides of the sheet formed after co-extrusion are continuous surfaces. This means that the shrinkage forces of the two continuous surfaces are similar or the same, which can also reduce the degree of warping. The substrate material in this embodiment is selected from zinc-aluminum-magnesium steel or galvanized steel sheet. The preferred substrate thickness is 0.4mm. It can be in sheet / roll / plate / strip form. Of course, those skilled in the art can choose according to requirements. In co-extrusion molding, the thermoplastic raw material is mainly modified polyolefin resin, or ABS, saline resin, TPE, or a composite of the above materials can be used. It is supplemented with necessary wear-resistant and aging-resistant additives, flame retardants, antioxidants, ultraviolet absorbers, and fluorescent powders. Then, the substrate is conveyed by a power roller to pass through the co-extrusion die at a uniform speed. At the same time, a single screw plastic extruder is used to extrude the molten modified polyolefin resin material into the co-extrusion die and co-extrude it onto the substrate that passes through the co-extrusion die simultaneously to form a floor. In some other embodiments, the floor can be further hot-pressed with patterns, but this embodiment will not be described in detail here.

[0024] Example 3 When the cold-bent substrate is subjected to a certain impact, the joint may open. In order to make the structure of the cold-bent substrate more stable, this embodiment proposes a preparation process of steel-plastic co-extrusion composite outdoor flooring based on the above embodiment 2. After the substrate is cold-bent, the substrate is welded and shaped. The welding points must include at least the substrate joints; the joints are where the two sides of the sheet substrate meet when it is bent and closed, and this position is the welding point 1. In addition, the upper and lower sides of the formed cold-bent substrate have at least one contact surface. The length of the contact surface in its own width direction is not less than the thickness of the sheet substrate. Since the sheet substrate used is thin, connecting the two can improve the strength. With higher strength, the tensile performance will be better, which can also reduce warping to a certain extent. Of course, the main purpose is to improve the fracture resistance. Therefore, any point on the upper side of the cold-bent substrate corresponding to the contact surface can be used as welding point 2. There is at least one welding point 2 on the contact surface. In this embodiment, four welding points 2 are used as an example. There is a contact surface on each side of welding point 1, and two welding points 2 on each contact surface. This can achieve the stability of the substrate structure. In addition, during welding, the substrate is conveyed along its length, and the length of the weld formed after welding can be the same as the substrate or at least one-third of the length of the final floor product. In some other embodiments, to reduce the continuous operation length of the production line, the substrate can be cut into the required size or finished size by a cutting device after cold bending or welding, and then the substrate can be fed into the co-extrusion die.

[0025] Furthermore, the invention can be implemented in other specific forms without departing from its spirit and essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0026] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A manufacturing process for steel-plastic co-extruded composite outdoor flooring, characterized in that, The process includes at least the following steps: cooling and shaping the co-extruded steel-plastic profile; during the cooling process, applying pressure to different positions of the steel-plastic profile from above and below to complete the shaping.

2. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 1, characterized in that, In co-extrusion molding, the substrate is fed into the co-extrusion die, and at the same time, molten thermoplastic raw material is extruded into the co-extrusion die and completely or partially covers the substrate that passes through the co-extrusion die simultaneously.

3. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 1, characterized in that, The substrate before co-extrusion molding is treated as follows: Sheet / roll / plate / strip substrates are cold-bent multiple times to form plate-like or frame-like structures, with the upper and lower sides of the frame-like structure having at least one contact surface.

4. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 3, characterized in that, After the substrate is cold-bent, it is welded and shaped.

5. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 3, characterized in that, At least one of the upper and lower sides of the frame structure is a continuous surface, and the other is a discontinuous surface.

6. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 5, characterized in that, One of the upper and lower sides of the frame structure is a continuous surface, and the other is a discontinuous surface.

7. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 3, characterized in that, The cross-section of the frame structure is M-shaped or Great Wall-shaped.

8. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 3, characterized in that, The length of the contact surface in the width direction of the frame structure is not less than the thickness of the sheet substrate.

9. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 4, characterized in that, During the welding shaping process, multiple points on the substrate are welded, including at least the substrate joint and any point on the upper side area of ​​the substrate corresponding to the contact surface.

10. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 9, characterized in that, During the welding and shaping process, five points on the substrate are welded. These five points include the substrate joint and two points on each of the two upper side areas that correspond one-to-one with the two contact surfaces of the substrate.

11. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 1, characterized in that, During the cooling process of the profile, pressure is applied to the sides and middle of the plate from the top and bottom of the profile to complete the shaping.

12. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 1, characterized in that, The substrate is made of galvanized steel sheet or zinc-aluminum-magnesium steel sheet.

13. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 2, characterized in that, The thermoplastic raw material includes one of the following: modified polyolefin resin, ABS, sarin resin, and TPE, or a combination of multiple materials.

14. The manufacturing process of the steel-plastic co-extruded composite outdoor flooring as described in claim 2, characterized in that, During co-extrusion molding, one or more of the following are added to the thermoplastic raw materials: wear-resistant and aging-resistant additives, flame retardants, antioxidants, ultraviolet absorbers, and fluorescent powders.

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