Method for recycling wood grain PVC material

Abstract

The application provides a wood grain PVC material recycling method, which comprises the following steps: a) crushing wood grain PVC material to be recycled to obtain crushed PVC small pieces; b) adding a pattern-eliminating master batch to the crushed PVC small pieces, uniformly mixing, and then performing extrusion molding to obtain a recycled product; the pattern-eliminating master batch is prepared from raw materials comprising the following components: 40-60 parts by weight of base resin; 20-30 parts by weight of polyvinyl chloride resin; 20-30 parts by weight of mineral filler; 5-15 parts by weight of plasticizer; 2-10 parts by weight of stabilizer; 1-5 parts by weight of antioxidant; 1-3 parts by weight of coupling agent; and 0-10 parts by weight of pigment. Compared with the prior art, the wood grain PVC material recycling method provided by the application uses a pattern-eliminating master batch with specific component content and specific steps to realize overall good interaction, eliminate color pattern phenomenon in the recycling and use of wood grain PVC material, improve the appearance quality of the product, and thus improve the recycling value of wood grain PVC material.

Description

Technical Field

[0001] This invention relates to the field of material recycling and reuse technology, and more specifically, to a method for recycling and reusing wood grain PVC material. Background Technology

[0002] With the trend of replacing steel with plastics and pursuing product lightweighting, end-user demand for personalized plastics is becoming increasingly prominent. Among these, PVC wood-grain composite materials that can be extruded to resemble wood grain patterns have seen widespread application. However, after a certain period of use or when replacing older products, the uneven color and texture issues during recycling of wood-grain PVC materials cause significant inconvenience, thus narrowing the material's application areas and reducing its value. Currently, there are many patents related to PVC wood-grain masterbatches, but no patents have been reported regarding the removal of wood grain patterns during recycling. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a method for recycling and reusing wood grain PVC material, which can eliminate the color and texture phenomenon in the recycling and reuse of wood grain PVC material, improve the appearance quality of the product, and thus increase the recycling and reuse value of wood grain PVC material.

[0004] This invention provides a method for recycling and reusing wood-grain PVC material, comprising the following steps:

[0005] a) Crush the wood-grain PVC material to be recycled to obtain crushed PVC pieces;

[0006] b) Add texture-reducing masterbatch to the crushed PVC pieces, mix evenly, and then extrude to obtain recycled products.

[0007] The anti-marking masterbatch is prepared from raw materials comprising the following components:

[0008] 40-60 parts by weight of matrix resin;

[0009] 20-30 parts by weight of polyvinyl chloride resin;

[0010] 20-30 parts by weight of mineral filler;

[0011] Plasticizer 5-15 parts by weight;

[0012] Stabilizer 2-10 parts by weight;

[0013] Antioxidant 1-5 parts by weight;

[0014] 1-3 parts by weight of coupling agent;

[0015] Pigment 0-10 parts by weight.

[0016] Preferably, the wood-grain PVC material to be recycled in step a) includes one or more of PVC profiles, PVC sheets, and PVC plates.

[0017] Preferably, the crushing requirement in step a) is as follows:

[0018] The content of blocks with a maximum size of less than 5 mm shall not be less than 90 wt% of the total, and the content of blocks with a maximum size of 5 mm to 8 mm shall not exceed 10 wt% of the total.

[0019] Preferably, the matrix resin in step b) is selected from one or more of POE resin, OBC resin, EVA resin, EEA resin and K resin.

[0020] Preferably, the mineral filler in step b) is selected from one or more of calcium carbonate, barium sulfate, clay, wollastonite, silica, diatomaceous earth, glass microspheres, talc, and mica;

[0021] The plasticizer is selected from one or more of the following: terephthalate plasticizers, phthalate plasticizers, citrate plasticizers, trimellitate plasticizers, cyclohexane dicarboxylate plasticizers, and phosphate plasticizers.

[0022] The stabilizer is selected from one or more of organotin stabilizers, calcium-zinc stabilizers, barium-zinc stabilizers, and organophosphite stabilizers;

[0023] The antioxidant is selected from one or more of hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants;

[0024] The coupling agent is selected from one or more of aluminate coupling agents, titanate coupling agents, and silane coupling agents.

[0025] Preferably, the preparation method of the anti-marking masterbatch in step b) is as follows:

[0026] First, polyvinyl chloride resin is mixed at high speed at 800r / min to 1200r / min to 65℃ to 75℃, plasticizer is added until completely absorbed, then stabilizer is added, and the mixture is mixed at high speed for 0.5min to 1.5min for pre-preparation. Then, mineral filler, pigment and coupling agent are mixed at high speed to 75℃ to 85℃ for 8min to 12min for pre-preparation. Finally, the matrix resin, antioxidant and the first two pre-prepared mixtures are mixed evenly and granulated by twin-screw extrusion to obtain texture-reducing masterbatch.

[0027] Preferably, the amount of the anti-texture masterbatch added in step b) is 3% to 6% of the mass of the crushed PVC pieces.

[0028] Preferably, the mixing speed in step b) is 80 r / min to 150 r / min, and the mixing time is 3 min to 5 min.

[0029] Preferably, the extrusion molding process described in step b) specifically includes:

[0030] It is directly extruded into granules, sheets or pipes at 170℃~200℃ using a conical twin-screw extruder.

[0031] This invention provides a method for recycling and reusing wood-grain PVC material, comprising the following steps: a) crushing the wood-grain PVC material to be recycled to obtain crushed PVC blocks; b) adding anti-marking masterbatch to the crushed PVC blocks, mixing evenly, and then extruding to obtain recycled products; the anti-marking masterbatch is prepared from raw materials comprising the following components: 40-60 parts by weight of matrix resin; 20-30 parts by weight of polyvinyl chloride resin; 20-30 parts by weight of mineral filler; 5-15 parts by weight of plasticizer; 2-10 parts by weight of stabilizer; 1-5 parts by weight of antioxidant; 1-3 parts by weight of coupling agent; and 0-10 parts by weight of pigment. Compared with the prior art, the method for recycling and reusing wood-grain PVC material provided by this invention selects anti-marking masterbatch with specific content and specific components, combined with specific processing steps, to achieve better overall interaction, which can eliminate the color mark phenomenon in the recycling and use of wood-grain PVC material, improve the appearance quality of the product, and thus increase the recycling value of wood-grain PVC material. Attached Figure Description

[0032] Figure 1 This is a rendering of the product obtained in Example 1 of the present invention;

[0033] Figure 2 This is a rendering of the product obtained in Comparative Example 1. Detailed Implementation

[0034] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] This invention provides a method for recycling and reusing wood-grain PVC material, comprising the following steps:

[0036] a) Crush the wood-grain PVC material to be recycled to obtain crushed PVC pieces;

[0037] b) Add texture-reducing masterbatch to the crushed PVC pieces, mix evenly, and then extrude to obtain recycled products.

[0038] The anti-marking masterbatch is prepared from raw materials comprising the following components:

[0039] 40-60 parts by weight of matrix resin;

[0040] 20-30 parts by weight of polyvinyl chloride resin;

[0041] 20-30 parts by weight of mineral filler;

[0042] Plasticizer 5-15 parts by weight;

[0043] Stabilizer 2-10 parts by weight;

[0044] Antioxidant 1-5 parts by weight;

[0045] 1-3 parts by weight of coupling agent;

[0046] Pigment 0-10 parts by weight.

[0047] The present invention first crushes the wood-grain PVC material to be recycled to obtain crushed PVC pieces.

[0048] In this invention, the wood grain PVC material to be recycled preferably includes one or more of PVC profiles (the surface may contain ASA coating), PVC sheets, and PVC plates, more preferably PVC profiles, PVC sheets, or PVC plates; this invention does not impose any special restrictions on the source of the wood grain PVC material to be recycled.

[0049] In this invention, the wood grain PVC material to be recycled must contain polyvinyl chloride (PVC) resin, and this invention does not impose any special restrictions on this.

[0050] In this invention, the crushing requirement is preferably:

[0051] The content of blocks with a maximum size of less than 5 mm shall not be less than 90 wt% of the total, and the content of blocks with a maximum size of 5 mm to 8 mm shall not exceed 10 wt% of the total.

[0052] After obtaining the crushed PVC pieces, the present invention adds texture-reducing masterbatch to the crushed PVC pieces, mixes them evenly, and then extrudes them to obtain recycled products.

[0053] In this invention, the anti-marking masterbatch is prepared from raw materials comprising the following components:

[0054] 40-60 parts by weight of matrix resin;

[0055] 20-30 parts by weight of polyvinyl chloride resin;

[0056] 20-30 parts by weight of mineral filler;

[0057] Plasticizer 5-15 parts by weight;

[0058] Stabilizer 2-10 parts by weight;

[0059] Antioxidant 1-5 parts by weight;

[0060] 1-3 parts by weight of coupling agent;

[0061] Pigment 0-10 parts by weight;

[0062] Preferably prepared from raw materials containing the following components:

[0063] 50 parts by weight of matrix resin;

[0064] 24-26 parts by weight of polyvinyl chloride resin;

[0065] 24-26 parts by weight of mineral filler;

[0066] Plasticizer 8-12 parts by weight;

[0067] Stabilizer 5-7 parts by weight;

[0068] Antioxidant 2-4 parts by weight;

[0069] 1-3 parts by weight of coupling agent;

[0070] 4 to 6 parts by weight of pigment.

[0071] In this invention, the matrix resin is preferably selected from one or more of POE resin, OBC resin, EVA resin, EEA resin, and K resin, and more preferably from POE resin, OBC resin, EVA resin, EEA resin, or K resin. This invention does not impose any special restrictions on the source of the matrix resin; commercially available products well known to those skilled in the art can be used.

[0072] The present invention does not impose any special restrictions on the source of the polyvinyl chloride resin, and commercially available products well known to those skilled in the art can be used.

[0073] In this invention, the mineral filler is preferably selected from one or more of calcium carbonate, barium sulfate, kaolin, wollastonite, silica, diatomaceous earth, glass microspheres, talc, and mica, and more preferably from calcium carbonate, barium sulfate, kaolin, wollastonite, silica, diatomaceous earth, glass microspheres, talc, or mica. This invention does not impose any special restrictions on the source of the mineral filler; commercially available products well-known to those skilled in the art can be used.

[0074] In this invention, the plasticizer is preferably selected from one or more of terephthalate plasticizers, phthalate plasticizers, citrate plasticizers, trimellitate plasticizers, cyclohexane dicarboxylate plasticizers, and phosphate plasticizers, and more preferably terephthalate plasticizers. This invention does not impose any special restrictions on the source of the plasticizer; commercially available products well known to those skilled in the art can be used.

[0075] In this invention, the stabilizer is preferably selected from one or more of organotin stabilizers, calcium-zinc stabilizers, barium-zinc stabilizers, and organophosphite stabilizers, more preferably organotin stabilizers, calcium-zinc stabilizers, barium-zinc stabilizers, or organophosphite stabilizers. This invention does not impose any special restrictions on the source of the stabilizer; commercially available products well-known to those skilled in the art can be used.

[0076] In this invention, the antioxidant is preferably selected from one or more of hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants, and more preferably hindered phenolic antioxidants. This invention does not impose any special restrictions on the source of the antioxidant; commercially available products well-known to those skilled in the art can be used.

[0077] In this invention, the coupling agent is preferably selected from one or more of aluminate coupling agents, titanate coupling agents, and silane coupling agents, more preferably aluminate coupling agents, titanate coupling agents, or silane coupling agents. This invention does not impose any special restrictions on the source of the coupling agent; commercially available products well known to those skilled in the art can be used.

[0078] The present invention does not impose any special restrictions on the source of the pigment; commercially available products well known to those skilled in the art can be used.

[0079] In this invention, the preferred method for preparing the anti-marking masterbatch is as follows:

[0080] First, polyvinyl chloride resin is mixed at high speed at 800 rpm to 1200 rpm until it reaches 65°C to 75°C. Plasticizer is added until it is completely absorbed, and then stabilizer is added. The mixture is then mixed at high speed for 0.5 min to 1.5 min for pre-preparation. Next, mineral filler, pigment, and coupling agent are mixed at high speed until it reaches 75°C to 85°C for 8 min to 12 min for pre-preparation. Finally, the matrix resin, antioxidant, and the two pre-prepared mixtures are mixed evenly and then granulated by twin-screw extrusion to obtain texture-reducing masterbatch.

[0081] More preferably:

[0082] First, polyvinyl chloride resin is mixed at high speed at 800 r / min, 900 r / min, 1000 r / min, or 1200 r / min to 70°C. Plasticizer is added until completely absorbed, and then stabilizer is added. The mixture is mixed at high speed for 1 min to prepare the premix. Next, mineral filler, pigment, and coupling agent are mixed at high speed to 80°C for 10 min to prepare the premix. Finally, the matrix resin, antioxidant, and the two premixes are mixed at 80 r / min to 150 r / min for 3 to 5 min until homogeneous. The mixture is then granulated by twin-screw extrusion (the screw speed of the twin-screw extruder is preferably 230 r / min to 280 r / min, more preferably 260 r / min, and the temperature is set from 100°C to 180°C) to obtain the texture-reducing masterbatch.

[0083] This invention is based on the preparation principle of wood grain masterbatch, which utilizes different colored masterbatches on resins with different melting points (mostly mixtures of PVC, PE, PC, ABS, etc.) to produce a wood grain effect. The specific content and composition of the aforementioned wood grain masterbatch are selected. This wood grain masterbatch first ensures its compatibility and processability with the wood grain PVC material, and secondly, it can solve the compatibility between different resins contained in the wood grain PVC material and the dispersion of different colors, ultimately achieving a uniform color and no color pattern in the extruded PVC products or granules.

[0084] In this invention, the amount of the anti-texture masterbatch added is preferably 3% to 6% of the mass of the crushed PVC pieces, more preferably 4% to 5%.

[0085] In this invention, the mixing speed is preferably 80 r / min to 150 r / min, more preferably 150 r / min, and the mixing time is preferably 3 min to 5 min, more preferably 5 min.

[0086] In a preferred embodiment of the present invention, the extrusion molding process is preferably as follows:

[0087] It is directly extruded into sheets or pipes at 170℃~200℃ using a conical twin-screw extruder;

[0088] More preferably:

[0089] The material is directly extruded into sheets or pipes at 180℃~190℃ using a conical twin-screw extruder, resulting in recyclable products.

[0090] In another preferred embodiment of the present invention, the extrusion molding process is preferably as follows:

[0091] The product is directly extruded into granules at 170℃~200℃ using a conical twin-screw extruder to obtain a recyclable product, which is then plasticized and pressed into tablets using a torque rheometer.

[0092] More preferably:

[0093] The product is directly extruded into granules at 180℃~190℃ using a conical twin-screw extruder to obtain recyclable products, which are then plasticized and pressed into tablets using a torque rheometer.

[0094] This invention first crushes the wood grain PVC material to be recycled, then adds anti-texture masterbatch to the crushed PVC material and directly extrudes it into products or extrudes it into PVC granules using a screw extruder, ultimately solving the color and texture problem in the recycling of wood grain PVC materials.

[0095] This invention provides a method for recycling and reusing wood-grain PVC material, comprising the following steps: a) crushing the wood-grain PVC material to be recycled to obtain crushed PVC blocks; b) adding anti-marking masterbatch to the crushed PVC blocks, mixing evenly, and then extruding to obtain recycled products; the anti-marking masterbatch is prepared from raw materials comprising the following components: 40-60 parts by weight of matrix resin; 20-30 parts by weight of polyvinyl chloride resin; 20-30 parts by weight of mineral filler; 5-15 parts by weight of plasticizer; 2-10 parts by weight of stabilizer; 1-5 parts by weight of antioxidant; 1-3 parts by weight of coupling agent; and 0-10 parts by weight of pigment. Compared with the prior art, the method for recycling and reusing wood-grain PVC material provided by this invention selects anti-marking masterbatch with specific content and specific components, combined with specific processing steps, to achieve better overall interaction, which can eliminate the color mark phenomenon in the recycling and use of wood-grain PVC material, improve the appearance quality of the product, and thus increase the recycling value of wood-grain PVC material.

[0096] To further illustrate the present invention, the following embodiments provide a detailed description. All raw materials used in the following embodiments of the present invention are commercially available, wherein the wood-grain PVC material to be recycled is a PVC sheet with a wood grain pattern.

[0097] The formula for the anti-texture masterbatch is as follows: 50 parts by weight of K resin, 25 parts by weight of polyvinyl chloride resin, 25 parts by weight of calcium carbonate mineral filler, 10 parts by weight of terephthalate plasticizer, 6 parts by weight of organotin stabilizer, 3 parts by weight of hindered phenolic antioxidant, 2 parts by weight of aluminate coupling agent, and 5 parts by weight of pigment.

[0098] The preparation method is as follows:

[0099] First, the polyvinyl chloride resin is mixed at high speed (900 r / min) to 70°C. Then, the plasticizer is added through a liquid pump until it is completely absorbed. The stabilizer is added, and the mixture is mixed at high speed for 1 min for pre-preparation. Next, the mineral filler, pigment, and coupling agent are added and mixed at high speed (1200 r / min) to 80°C for 10 min for pre-preparation. Finally, the K resin, antioxidant, and the first two pre-prepared mixtures are mixed evenly in a low-speed mixing tank (150 r / min for 5 min). The mixture is then extruded and granulated using a twin-screw extruder (temperature set at 100°C to 180°C, screw speed at 260 r / min) to obtain the texture-reducing masterbatch.

[0100] Example 1

[0101] (1) The wood grain PVC material to be recycled is crushed into small pieces, and the content of the pieces with the largest size less than 5mm is not less than 90wt% of the total, and the content of the pieces with the largest size between 5mm and 8mm is not more than 10wt% of the total.

[0102] (2) Add 5% by weight of the texture-reducing masterbatch to the crushed PVC pieces, mix evenly (mix at low speed of 150 r / min for 5 min), and then directly extrude into sheets using a conical twin-screw extruder at 185℃; the surface of the product has no obvious color marks, the color is uniform, and the total color difference at any point within a unit area is less than 2. See [reference needed] Figure 1 As shown.

[0103] Comparative Example 1

[0104] (1) The wood grain PVC material to be recycled is crushed into small pieces, and the content of the pieces with the largest size less than 5mm is not less than 90wt% of the total, and the content of the pieces with the largest size between 5mm and 8mm is not more than 10wt% of the total.

[0105] (2) The crushed PVC pieces are directly extruded into sheets using a conical twin-screw extruder at 185°C; the surface of the product has obvious color patterns, uneven color, and the total color difference at any point within a unit area exceeds 2. See [reference needed] Figure 2 As shown.

[0106] The gloss comparison of the boards is shown in Table 1 below.

[0107] Table 1 Comparison of gloss levels of sheet materials

[0108] 20-degree angle 50 65 60-degree angle 53 70

[0109] Example 2

[0110] (1) The wood grain PVC material to be recycled is crushed into small pieces, and the content of the pieces with the largest size less than 5mm is not less than 90wt% of the total, and the content of the pieces with the largest size between 5mm and 8mm is not more than 10wt% of the total.

[0111] (2) Add 5% of the mass of the anti-texture masterbatch to the crushed PVC pieces, mix evenly (mix at low speed of 150r / min for 5min), and then directly extrude into granules at 185℃ through a conical twin-screw extruder. Then, plasticize and press the granules through a torque rheometer to obtain the product. The surface of the product has no obvious color marks, the color is uniform, and the total color difference at any point within a unit area is less than 2.

[0112] The color difference values ​​for granule tablets are shown in Table 2 below.

[0113] Table 2 Color difference values ​​of granule tablets

[0114] Total color difference value 0.92 0.8 0.75 0.68

[0115] Example 3

[0116] (1) The wood grain PVC material to be recycled is crushed into small pieces, and the content of the pieces with the largest size less than 5mm is not less than 90wt% of the total, and the content of the pieces with the largest size between 5mm and 8mm is not more than 10wt% of the total.

[0117] (2) Add 5% of the mass of the anti-texture masterbatch to the crushed PVC pieces, mix evenly (mix at low speed of 150r / min for 5min), and then directly extrude the pipe at 185℃ through a conical twin-screw extruder; the surface of the product has no obvious color marks, the color is uniform, and the total color difference at any point within the unit area is less than 2.

[0118] Comparative Example 2

[0119] (1) The wood grain PVC material to be recycled is crushed into small pieces, and the content of the pieces with the largest size less than 5mm is not less than 90wt% of the total, and the content of the pieces with the largest size between 5mm and 8mm is not more than 10wt% of the total.

[0120] (2) The crushed PVC pieces are directly extruded into pipes at 185°C using a conical twin-screw extruder; the surface of the product has obvious color patterns, the color is uneven, and the total color difference at any point within a unit area exceeds 2.

[0121] The comparison of pipe impact breakage is shown in Table 3 below.

[0122] Table 3 Comparison of Pipe Impact Crushing

[0123] Impact test crack Unbreakable

[0124] In summary, this invention appropriately increases the viscosity of PVC scrap during the melting process by utilizing the low flowability and high viscosity of the elastomer resin component. This reduces the material's fluidity and improves the shear force transmission efficiency, promoting the compatibility of resins with different melting points that produce color streaks in the PVC scrap. This results in a stable and uniform appearance color in the re-extruded products made from the scrap. The excellent compatibility between the polyvinyl chloride component and the PVC scrap ensures smooth processing. The various additives enhance the gloss of the re-extruded products. This invention solves the problem of difficult wood grain removal in the recycling and reuse of PVC profiles with wood grain patterns, filling the product gap in this field due to the lack of functional masterbatches. It eliminates the color streaks in the recycling and reuse of wood grain PVC materials, improves the appearance quality of the products, and greatly increases the recycling value of wood grain PVC materials.

[0125] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for recycling and reusing wood-grain PVC material, characterized in that, Includes the following steps: a) The wood-grain PVC material to be recycled is crushed to obtain crushed PVC pieces; The requirements for the crushing are as follows: The content of blocks with a maximum size of less than 5mm shall not be less than 90wt% of the total, and the content of blocks with a maximum size of 5mm to 8mm shall not exceed 10wt% of the total. b) Add texture-reducing masterbatch to the crushed PVC pieces, mix evenly, and then extrude to obtain recycled products. The anti-marking masterbatch is prepared from raw materials containing the following components: 40-60 parts by weight of matrix resin; 20-30 parts by weight of polyvinyl chloride resin; 20-30 parts by weight of mineral filler; Plasticizer 5-15 parts by weight; Stabilizer 2-10 parts by weight; Antioxidant 1-5 parts by weight; 1-3 parts by weight of coupling agent; 0-10 parts by weight of pigment; The matrix resin is selected from K resin, which can increase the viscosity of PVC crushed material during the melting process; the mineral filler is selected from calcium carbonate; the plasticizer is selected from terephthalate plasticizers; the stabilizer is selected from organotin stabilizers; the antioxidant is selected from hindered phenolic antioxidants; and the coupling agent is selected from aluminate coupling agents. The amount of the texture-removing masterbatch added is 3% to 6% of the mass of the crushed PVC pieces; The specific method for preparing the anti-marking masterbatch is as follows: First, polyvinyl chloride resin is mixed at high speed at 800r / min~1200r / min to 65℃~75℃, plasticizer is added until completely absorbed, then stabilizer is added, and high-speed mixing is carried out for 0.5min~1.5min for pre-preparation. Then, mineral filler, pigment and coupling agent are mixed at high speed to 75℃~85℃ for 8min~12min for pre-preparation. Finally, the matrix resin, antioxidant and the first two pre-prepared mixtures are mixed evenly and granulated by twin-screw extrusion to obtain texture-reducing masterbatch.

2. The method for recycling and reusing wood-grain PVC material according to claim 1, characterized in that, The wood-grain PVC material to be recycled in step a) is a PVC profile.

3. The method for recycling and reusing wood-grain PVC material according to claim 2, characterized in that, The PVC profile is a PVC sheet or PVC plate.

4. The method for recycling and reusing wood-grain PVC material according to claim 1, characterized in that, The mixing speed in step b) is 80 r / min to 150 r / min, and the time is 3 min to 5 min.

5. The method for recycling and reusing wood-grain PVC material according to claim 1, characterized in that, The extrusion molding process described in step b) is specifically as follows: It is directly extruded into granules, sheets or pipes at 170℃~200℃ using a conical twin-screw extruder.

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