An online modification extrusion double-pelletizing device and a PP online modification extrusion double-pelletizing device

Abstract

The utility model provides an online modification extrusion double pelletizing device and PP online modification extrusion double pelletizing device, include: main extrusion line, including first extruder, melt pump, filter equipment and first pelletizing device, first extruder, melt pump, filter equipment and first pelletizing device are connected in proper order, modification extrusion line, including second extruder, at least one function material feeding scale and second pelletizing device, second extruder is connected with second pelletizing device, function material feeding scale is connected with second extruder, second extruder is double screw extruder, and it has at least one meshing block screw section or toothed disc screw section on its screw, the position of meshing block screw section or toothed disc screw section corresponds with the position of function material feeding scale, the shunt pipeline is used to melt in the main extrusion line before entering first pelletizing device and shunts part melt in the main machine out line to modification extrusion line.

Description

Technical Field

[0001] This utility model generally relates to the field of extrusion equipment, and more particularly to a modified extrusion equipment and process. Background Technology

[0002] Physical modification of polymer materials includes filler modification, blending modification, and reinforcement modification. Polymer materials are aggregates, and many polymers have extremely high molecular weights. This results in high viscosity, and they may even be solid at room temperature and pressure. With evolving human needs, the development of polymer materials tends towards composite modification, showcasing their superior properties and supplementing any missing properties. Polypropylene (PP) is a semi-crystalline thermoplastic polymer produced from propylene monomers through an addition polymerization reaction. Adding organic or inorganic additives to the PP matrix during mixing and compounding processes yields high-performance PP composite materials, mainly including filler modification, blending modification, and reinforcement modification.

[0003] (1) Filler modification

[0004] Filler modification involves adding fillers such as silicates, silica, cellulose, glass fibers, calcium carbonate, clay, talc, and mica to polypropylene (PP) to improve its heat resistance, reduce costs, increase rigidity, and reduce molding shrinkage. However, filler modification can lead to a decrease in the impact strength and elongation of PP. Different fillers have different characteristics and effects in filler modification. For example, glass fiber is a high-performance inorganic non-metallic whisker that is inexpensive, has good insulation, strong heat resistance, good corrosion resistance, and high mechanical strength, making it widely used. PP modified with glass fiber shows significant performance improvement, but a noticeable improvement in mechanical properties only occurs when the glass fiber content reaches approximately 30%. Excessive addition can lead to insufficient impregnation of some glass fibers, resulting in poor bonding between the polymer matrix and the glass fiber interface, causing a decrease in the mechanical strength of the composite material. Furthermore, as the amount of glass fiber increases, the flowability of the composite material decreases, affecting the PP molding and processing capabilities. Difficulties can be overcome; calcium carbonate can reduce product costs, improve product performance, and enhance its rigidity, hardness, heat resistance, and dimensional stability; kaolin, also known as clay, is a plastic filler with excellent electrical insulation properties and can be used to manufacture various wire sheaths. It can also be used as a crystallizing nucleating agent to improve the uniformity of material crystallization, increase product transparency, and has a certain flame-retardant effect, making it suitable for auxiliary flame-retardant modification; talc, as a filler, can improve the rigidity, hardness, flame-retardant properties, electrical insulation properties, and dimensional stability of products, and also has a lubricating effect; mica can improve the modulus and heat resistance of PP, reduce creep, prevent product warping, and decrease molding shrinkage.

[0005] (2) Blending modification

[0006] Blending modification refers to the process of mixing two or more polymer materials and additives at a certain temperature to change their properties. For example, to improve low-temperature impact resistance, it can be blended with ethylene propylene rubber (EPDM), POE (polyolefin elastomer), EVA (ethylene-vinyl acetate copolymer), and SBS (styrene-butadiene block copolymer). However, in blending modification, attention must be paid to the compatibility between polymers. Only when a partially incompatible multiphase system is formed, while maintaining uniform dispersion, can the desired modification effect be achieved. The blending modification process is easy to control, has a short production cycle, and low cost. It can improve various properties of PP, such as colorability, processability, antistatic properties, and impact resistance. Polymer blending can combine the outstanding properties of each component and compensate for their shortcomings, significantly improving the overall performance of the blend. However, the low-temperature resistance and aging resistance of blended modified PP are still not ideal. During blending modification, shear force may cause some macromolecular chains to be cut off to form free radicals and graft or block copolymers. These new copolymers can also effectively compatibilize PP.

[0007] (3) Enhancement and modification

[0008] Adding fibrous materials to plastics can significantly improve the strength of the plastic material, hence the term "reinforcement modification." Materials with a large diameter-to-thickness ratio can significantly improve the flexural modulus (rigidity) of plastic materials, which can also be referred to as "reinforcement modification."

[0009] The reinforcing materials used in the reinforcement and modification of PP (polypropylene) are mainly glass fibers and their products, in addition to carbon fibers, organic fibers, boron fibers, whiskers, etc. Among glass fiber reinforced PP, alkali-free glass fibers and medium-alkali glass fibers are most commonly used, with alkali-free glass fibers having the largest usage. The diameter of the glass fibers should be controlled within the range of 6–15 μm, and the length must be maintained between 0.25–0.76 mm to ensure both product performance and good fiber dispersion. It is generally believed that a glass fiber length greater than 0.2 mm in the product is needed for a modification effect. The glass fiber content (mass fraction) is optimal between 10% and 30%; performance deteriorates when it exceeds 40%. Furthermore, adding organosilane coupling agents can help form a good interface between the glass fibers and PP, improving the flexural modulus, hardness, load deformation temperature, and especially dimensional stability of the composite system.

[0010] Because glass fiber reinforced PP can improve mechanical strength and heat resistance, and has good resistance to water vapor, chemical corrosion and creep, it can be used as an engineering plastic in many applications, such as fan blades, heater grilles, impeller pumps, lamp covers, electric furnace and heater housings, etc.

[0011] While the production of polypropylene is developing rapidly, its performance is also constantly being improved, which makes its application breadth and depth constantly changing. In recent years, some new varieties of polypropylene with more unique properties have emerged, such as transparent polypropylene and high melt strength polypropylene, either by improving the polymerization reaction or by taking measures during granulation after polymerization.

[0012] The above-mentioned physical modification method generally involves melting the granulated polymer material in a screw extruder, adding a modifier for modification treatment, and then granulating it to form modified particles.

[0013] The background section contains only information about technologies known to the applicant and does not necessarily represent existing technologies in the field. Summary of the Invention

[0014] To address one or more of the problems existing in the prior art, this utility model provides an online modified extrusion dual granulation device, comprising:

[0015] The main extrusion line includes a first extruder, a melt pump, a filter device, and a first pelletizing device, which are connected in sequence.

[0016] A modified extrusion line includes a second extruder, at least one functional material feeder, and a second pelletizing device. The second extruder is connected to the second pelletizing device, and the functional material feeder is connected to the second extruder. The second extruder is a twin-screw extruder, and its screw has at least one meshing block screw section or toothed disc screw section. The position of the meshing block screw section or toothed disc screw section corresponds to the position of the functional material feeder.

[0017] The diversion pipeline is used to divert a portion of the melt from the main extrusion line to the modified extrusion line before it enters the first pelletizing unit.

[0018] Furthermore, as a preferred embodiment, the first pelletizing device is an underwater pelletizing device.

[0019] As another preferred embodiment, the second pelletizing device is a strip pelletizing device.

[0020] Furthermore, the main extrusion line also includes a drain valve, which is located between the melt pump and the filter device.

[0021] Furthermore, the first extruder includes a pressure build-up section.

[0022] Furthermore, the functional material feeder is connected to the second extruder via a side-feeding method.

[0023] Furthermore, the modified extrusion line is connected to two or more functional material feeders.

[0024] Furthermore, the diversion pipeline includes a melt pipe, a buffer hopper, and a gear pump, which are connected in sequence; wherein, the melt pipe is equipped with a control valve and a drain valve, and the gear pump is located between the buffer hopper and the second extruder.

[0025] Furthermore, both the melt tube and the buffer hopper are equipped with jacketed insulation devices.

[0026] This application also provides a PP online modified extrusion dual granulation device. Using the above-described device, the first extruder is a twin-screw extruder, and the upstream section of the screw is a meshing block screw used to complete the grinding and melting of PP powder. Preferably, the length of the meshing block screw is 5D.

[0027] Preferably, the functional material feeder is configured such that a polymer material feeder and an inorganic filler feeder are sequentially connected on the second extruder along the melt travel direction.

[0028] Furthermore, the length of the meshing block screw on the second extruder corresponding to the polymer material feed scale is 4D; the length of the meshing block screw on the second extruder corresponding to the inorganic filler feed scale is 6D.

[0029] Furthermore, the second extruder is also connected to an additive feeder.

[0030] Furthermore, the length of the engagement block screw on the second extruder corresponding to the additive feeder is 2D.

[0031] Furthermore, the first extruder is also equipped with a melt devolatilization section.

[0032] This application employs two extrusion lines operating simultaneously to complete the physical modification of polymer materials, ensuring the fulfillment of various modification needs during the extrusion granulation process. It simultaneously produces polymer particles and the desired physically modified particles, effectively streamlining the process, reducing production costs, and guaranteeing the quality of both the produced polymer particles and the modified particles. This application's solution is particularly effective in improving the efficiency of online modification of PP materials. PP material is in powder form at room temperature and pressure; besides the large demand for pure PP material, there is also a significant demand for its various physically modified products. Based on an online modified extrusion dual granulation device, this application designs a precise twin-screw combination structure for the main extrusion line and the modified extrusion line for PP materials, resulting in a significant improvement in efficiency during actual production. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0034] Figure 1 This is a schematic diagram of the structure of an online modified extrusion dual granulation device according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the structure of a PP online modified extrusion dual granulation device according to an embodiment of the present invention;

[0036] Among them, 1: main extrusion line, 2: modified extrusion line, 3: distribution pipeline, 11: first extruder, 12: melt pump, 13: filter device, 14: first pelletizing device, 111: melt plasticizing section, 10: meshing block screw, 112: melt devolatilization section, 113: pressure building section, 15: drain valve, 21: second extruder, 22: second pelletizing device, 201: first functional material feeder ( Figure 1 ) or polymer material feed ( Figure 2 ), 202: Second function material feeding scale ( Figure 1 ) or inorganic filler feed ( Figure 2 ), 203: Additive feeder, 211, 212, 213: Meshing block screw section, 31: Melt tube, 32: Buffer hopper, 33: Gear pump, 34: Control valve, 35: Drain valve. Detailed Implementation

[0037] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0038] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0039] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or connections that allow for communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0040] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0041] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0042] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0043] Example 1:

[0044] like Figure 1 As shown, the first embodiment of this utility model provides an online modified extrusion dual granulation device, including: a main extrusion line 1, a modified extrusion line 2, and a diversion pipeline 3. The main extrusion line 1 obtains initial polymer material particles through extrusion melting and granulation. The diversion pipeline 3 diverts a portion of the melt from the main extrusion line 1 to the modified extrusion line 2 for modification treatment. The modified extrusion line 2 also uses an extruder, where filler is added and mixed, extruded, and granulated to ultimately obtain modified polymer composite material particles.

[0045] The specific structures of the main extrusion line 1, the modified extrusion line 2, and the branch pipeline 3 are described in detail below.

[0046] Main extrusion line 1

[0047] The main extrusion line includes a first extruder 11, a melt pump 12, a filter device 13, and a first pelletizing device 14, which are connected sequentially. The first pelletizing device 14 is an underwater pelletizing device. The first extruder 11 is a twin-screw extruder. Generally, the first extruder 11 only needs to meet the necessary conditions for online modification if it has a pressure build-up section 113. However, for different materials, other extrusion sections can be added to the first extruder. For example, for the online modification of PP material that needs to be protected in this application, the first extruder 11 also needs to be equipped with a melt plasticizing section 111 and a melt devolatilization section 112 at the upstream end. The melting and plasticizing section 111 uses a combination of a conveying element and a meshing screw. The conveying element continuously supplies PP powder, while the meshing screw provides shear heat to melt it. The melt devolatilization section 112 uses a combination of a conveying element and a toothed disc screw. The toothed disc shears the molten PP, increasing its specific surface area and facilitating devolatilization. The pressure-building section 113 uses a conventional twin-screw compressor for conveying, moving the material downstream to the melt pump 12 and simultaneously increasing the material pressure, typically to 5-10 MPa. Under the action of the pressure-building section 112, the molten material moves from the mixing and dispersing section 111 to the pressure-building section 113 and then flows into the melt pump 12, where the pressure rapidly increases to 15-30 MPa. The filtration device 13 typically uses a filter screen. The mesh size of the filter screen can be selected based on the molecular size of the material after cross-linking or oxidation; mesh size selection is a conventional method used by those skilled in the art. The filter device 13 can filter out unqualified parts such as cross-linked materials or yellow materials (usually caused by oxidation), thereby improving the purity of the product. After the material passes through the high-resistance filter device 13, the pressure drops rapidly, generally to 5-10 MPa. The relatively clean polymer material after filtration is solidified and granulated by the underwater pelletizing device 14 (the first pelletizing device) to obtain polymer material particles.

[0048] As a preferred embodiment, a drain valve 15 is provided between the melt pump 12 and the filter device 13 for detecting and discharging waste materials such as aged yellow material from the equipment.

[0049] Modified extrusion line 2

[0050] The modified extrusion line includes a second extruder 21, a second pelletizing device 22, and at least one functional material feeder. For example... Figure 1As shown, this embodiment uses two types of fillers as examples: a first functional material feeder 201 and a second functional material feeder 202. A diversion pipeline 3 inputs a portion of the polymer melt from the main extrusion line to the second extruder 21. Research in this application has found that excessively large diversion flows are difficult to control. The diverted portion of melt generally accounts for less than 30% of the melt from the main extrusion line, ensuring balanced operation of the two extrusion lines. When the diverted portion of melt accounts for 8-13% of the melt from the main extrusion line, it is more beneficial for the balance of the two extrusion lines, with lower control difficulty and higher stability. The second extruder 21 is connected to the second pelletizing device 22, and the first functional material feeder 201 and the second functional material feeder 202 are respectively connected to the second extruder 21. The second extruder 21 is a twin-screw extruder. On the twin screw of the second extruder, corresponding positions of the first functional material feeder 201 and the second functional material feeder 202 are configured as interlocking screw sections, i.e., interlocking screw sections 211 and 212 are formed on the twin screw. The purpose of the interlocking screw segments 211 and 212 is to achieve sufficient dispersion and mixing of the polymer melt and the added functional filler. Those skilled in the art can determine the length of these segments based on the composite material to be dispersed. The polymer melt is mixed by the interlocking screw segments 211 and 212 and then fed into the second pelletizing device 22 under the drive of the twin screws. Alternatively, a toothed disc screw can be used instead of the interlocking screw, forming toothed disc screw segments 211 and 212 on the twin screw. Most functional materials are inorganic materials such as fibers and granules, while some are macromolecular organic materials. These fillers differ significantly in shape from the molten polymer, making mixing difficult and leading to a challenging filling process. Existing mixing processes for these fillers are mainly completed in mixing tanks with stirring or shearing functions, making it difficult to complete directly on an extrusion line. To overcome this difficulty, this application decomposes the functional materials into multiple functional material feeders based on the filler morphology and function, which are then fed to multiple interlocking screw segments using a side-feeding method. The second pelletizing device 22 is a strand pelletizing device, which is a commonly used pelletizing device in the field. The composite material after being modified by the second extruder 21 is extruded into the strand pelletizing device 22 for stretching, cooling, and pelletizing, and finally the composite material particles are obtained.

[0051] Diversion pipe 3

[0052] The diversion pipeline 3 is used to divert a portion of the melt from the main extrusion line 1 to the modified extrusion line 2 before it enters the first pelletizing device 14. The diversion pipeline 3 includes a melt pipe 31, a buffer hopper 32, and a gear pump 33, which are connected sequentially. The melt pipe is equipped with a control valve 34 and a drain valve 35. The gear pump 33 is located between the buffer hopper 32 and the second extruder 21. One end (feed end) of the melt pipe 31 is located upstream of and connected to the first pelletizing device 14. At this point, the melt pressure on the main extrusion line is lowest, which is more conducive to controlling the balanced operation of the main extrusion line 1 and the modified extrusion line 2. In this embodiment, the feed end of the melt pipe 31 is located between the filter device 13 and the first pelletizing device 14. The melt pipe 31 feeds the diverted melt into the buffer hopper 32, and then, after being pressurized by the gear pump 33, it is pumped into the second extruder 21. Both the melt pipe 31 and the buffer hopper 32 are equipped with jacketed insulation devices to ensure the fluidity of the melt. Before opening the control valve 34, the air in the modified extrusion line 2 is first purged with nitrogen or other inert gas. Before the second extruder 21 of the modified extrusion line 2, the control valve 34 is opened. The melt from the main extrusion line 1 enters the melt pipe 31 and is detected by the drain valve 35. If the melt does not meet the process requirements, the grounding terminal of the drain valve 35 is opened to discharge it. When the detected melt meets the process requirements, the grounding terminal is closed, and the melt enters the buffer hopper 32. The material storage amount in the buffer hopper 32 can be controlled by the control valve 34, and can be adjusted in real time according to the processing speed of the modified extrusion line 2.

[0053] Example 2:

[0054] like Figure 2 As shown, this embodiment demonstrates an online modified extrusion dual-granulation device for PP. Polypropylene (PP) is solid at room temperature and pressure. This embodiment enables online physical modification of solid PP. This embodiment makes precise improvements based on the device of Example 1. The main improvement is that the first extruder 11 adopts a twin-screw extruder, and the upstream section of the screw is a meshing block screw 10, which is used to complete the grinding and melting of PP powder. The length of the meshing block screw 10 is 5D, where D is in mm. The actual length of D is related to the model of the extruder. For example, if the model of the extruder is GP52, then D = 52 mm. The interpretation of "D" in the following examples is the same. Figure 1As shown, this embodiment describes an online modified extrusion dual-granulation device for PP materials. The first extruder 11 is configured to include an upstream melt plasticizing section 111, a midstream melt devolatilization section 112, and a downstream pressure-building section 113. The melt plasticizing section 111 uses a combination of a conveying element and a meshing screw 10. The conveying element continuously supplies PP powder, while the meshing screw provides shear heat and melts it. The melt devolatilization section 112 uses a combination of a conveying element and a toothed disc screw. The toothed disc shears the molten PP, increasing its specific surface area and facilitating devolatilization. For example... Figure 2 As shown, the functional material feeder is configured by sequentially connecting a polymer material feeder 201, an inorganic filler feeder 202, and an additive feeder 203 along the melt travel direction on the second extruder. The polymer material feeder 201 is used to precisely feed polymer modifiers, such as POE (polyolefin elastomer), to the second extruder 21. The inorganic filler feeder 202 is used to precisely feed inorganic fillers, such as mixtures of glass fiber, carbon fiber, calcium carbonate, clay, and talc, to the second extruder 21. The additive feeder 203 is used to precisely feed additives, such as commonly used antioxidants and flame retardants, to the second extruder 21. The polymer material feeder 201, inorganic filler feeder 202, and additive feeder 203 are all configured as meshing block screws on the twin screws within the second extruder 2. (See [reference]). Figure 2 The screw sections 211, 212, and 213 are respectively the meshing block screw sections; all other twin screws are conventional twin screws. The length of the meshing block screw 211 corresponding to the polymer material feed scale 201 is 4D; the length of the meshing block screw 212 corresponding to the inorganic filler feed scale 202 is 6D; and the length of the meshing block screw 213 corresponding to the additive feed scale 203 is 2D. The PP melt diverted from the main extrusion line 1 to the modified extrusion line 2 is first thoroughly mixed with the polymer modifier fed in by the polymer feed scale 201 under the action of the corresponding meshing block screw, then thoroughly mixed with the inorganic filler conveyed by the inorganic filler feed scale 202, and finally thoroughly mixed with the additives conveyed by the additive feed scale 203. Under the action of the twin screws, the PP melt mixed with the polymer modifier, inorganic filler, and additives is extruded to the pelletizing device 22, finally obtaining modified PP particles.

[0055] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An online modified extrusion dual granulation device, characterized in that, include: The main extrusion line includes a first extruder, a melt pump, a filter device, and a first pelletizing device, which are connected in sequence. A modified extrusion line includes a second extruder, at least one functional material feeder, and a second pelletizing device. The second extruder is connected to the second pelletizing device, and the functional material feeder is connected to the second extruder. The second extruder is a twin-screw extruder, and its screw has at least one meshing block screw section or toothed disc screw section. The position of the meshing block screw section or toothed disc screw section corresponds to the position of the functional material feeder. The diversion pipeline is used to divert a portion of the melt from the main extrusion line to the modified extrusion line before it enters the first pelletizing unit.

2. The online modified extrusion dual granulation device according to claim 1, characterized in that, The first pelletizing device is an underwater pelletizing device.

3. The online modified extrusion dual granulation device according to claim 1, characterized in that, The second pelletizing device is a strip pelletizing device.

4. The online modified extrusion dual granulation device according to claim 1, characterized in that, The main extrusion line also includes a drain valve, which is located between the melt pump and the filter device.

5. The online modified extrusion dual granulation device according to claim 1, characterized in that, The first extruder includes a pressure build-up section.

6. The online modified extrusion dual granulation device according to claim 1, characterized in that, The functional material feeder is connected to the second extruder via a side-feeding method.

7. The online modified extrusion dual granulation device according to claim 1, characterized in that, The modified extrusion line is connected to two or more functional material feeders.

8. The online modified extrusion dual granulation device according to claim 1, characterized in that, The diversion pipeline includes a melt pipe, a buffer hopper, and a gear pump, which are connected in sequence. The melt pipe is equipped with a control valve and a drain valve, and the gear pump is located between the buffer hopper and the second extruder.

9. The online modified extrusion dual granulation device according to claim 8, characterized in that, Both the melt tube and the buffer hopper are equipped with jacketed insulation devices.

10. A dual granulation device for online modified PP extrusion, characterized in that, The apparatus according to any one of claims 1-6 is used, wherein the first extruder is a twin-screw extruder, and the upstream section of the screw is a meshing block screw, for completing the grinding and melting of PP powder.

11. The PP online modified extrusion dual granulation device according to claim 10, characterized in that, The length of the meshing block screw is 5D.

12. The PP online modified extrusion dual granulation device according to claim 10, characterized in that, The functional material feeder is configured such that a polymer material feeder and an inorganic filler feeder are sequentially connected on the second extruder along the melt travel direction.

13. The PP online modified extrusion dual granulation device according to claim 12, characterized in that, The length of the meshing block screw on the second extruder corresponding to the polymer material feed scale is 4D.

14. The PP online modified extrusion dual granulation device according to claim 12, characterized in that, The length of the meshing block screw on the second extruder corresponding to the inorganic filler feed scale is 6D.

15. The PP online modified extrusion dual granulation device according to claim 12, characterized in that, The second extruder is also connected to an additive feeder.

16. The PP online modified extrusion dual granulation device according to claim 15, characterized in that, The length of the meshing block screw on the second extruder corresponding to position 203 of the additive feed scale is 2D.

17. The PP online modified extrusion dual granulation device according to claim 10, characterized in that, The first extruder is also equipped with a melt devolatilization section.

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