Online modified combined extrusion equipment and extrusion method thereof

Abstract

The present application provides an online modified co-extrusion device and an extrusion method thereof, and relates to the field of modified extrusion equipment and process technology. The online modified co-extrusion device includes: a first extrusion system, a second extrusion system, a melt transfer device, and a rolling system; the melt transfer device has a liquid inlet end and a liquid outlet end, the liquid inlet end is connected to the underwater pelletizing device of the first extrusion system, and the liquid outlet end is connected to the second extrusion system, for transferring part of the melt of the first extrusion system to the second extrusion system; the second extrusion system includes a twin-screw extruder, a die head installed at the injection end of the twin-screw extruder, and at least one modifier injection device connected to the twin-screw extruder; the twin-screw extruder has at least one set of modifier receiving and mixing sections, the modifier receiving and mixing sections include an injection barrel and a toothed disc twin-screw, and the toothed disc twin-screw is located in the accommodating space of the injection barrel.

Description

Technical Field

[0001] The present application generally relates to the field of extruder equipment, and more particularly to a modified extrusion equipment and process. Background Art

[0002] After synthesis, polymer materials contain large amounts of solvents and impurities, requiring devolatilization and impurity removal before pelletization and storage as solids for future use. Extrusion granulation is a common method in the polymer materials industry. After thorough mixing, the polymer material is added to the extruder hopper. A heater on the outside of the extruder barrel heats the material inside to melting temperature through heat conduction. As the machine operates, the screw inside the barrel propels the material forward. During this movement, the material rubs and shears against the barrel, screw, and each other, generating significant heat. This heat, combined with heat conduction, causes the added material to continuously melt. The molten material is continuously and stably conveyed to a precisely shaped die. After passing through the die, the fluidized material assumes an approximate die shape and then enters a cooling and setting device, where it solidifies while maintaining its defined shape. The extruded material is then fed into a pelletizer, which cuts the round plastic strips into pellets. Finally, the pellets are weighed and bagged for injection molding.

[0003] With the increasing demand for multiple composite polymer materials, various modification treatments are required for the actual production of final products. However, due to equipment limitations, it is difficult to complete the modification treatment before pelletizing. In addition, the final product also needs to be made into the corresponding shape of the product. For example, the modified EVA film used in solar panels has a film-like final product. In the prior art, the pelletized polymer material is melted in a screw extruder, and a modifier is added to modify it and then granulated to form modified particles. The modified particles are then formed into films through a melting device or a coating and / or laminating device. In some actual industrial production practices, EVA and a peroxide modifier are also mixed onto a hard carrier such as a glass sheet, and then placed in a hot pressing device for modification and cross-linking reaction and pressed into a film. These methods are difficult to complete continuously, resulting in loss of materials and time. Summary of the Invention

[0004] In view of one or more problems existing in the prior art, the present application provides an online modification combined extrusion device, comprising: a first extrusion system, a second extrusion system, a melt transfer device and a rolling system;

[0005] The melt transfer device has a liquid inlet end and a liquid outlet end, the liquid inlet end is connected to the first extrusion system, and the liquid outlet end is connected to the second extrusion system, and is used to transfer part of the melt of the first extrusion system to the second extrusion system;

[0006] The second extrusion system includes a twin-screw extruder, a die head installed at the injection end of the twin-screw extruder, and at least one modifier injection device connected to the twin-screw extruder; the twin-screw extruder has at least one set of modifier receiving and mixing sections, the modifier receiving and mixing sections including a liquid injection barrel and a toothed disc twin screw, the toothed disc twin screw being located in the accommodating space of the liquid injection barrel; wherein the liquid injection barrel has at least one liquid injection pipe, the modifier injection device being connected to the liquid injection pipe; the modifier receiving and mixing sections being located downstream along the direction of melt travel;

[0007] The roller pressing system includes at least one set of roller cross-linking components and a winding device;

[0008] The die head is adapted to the pressure roller cross-linking assembly and is used for ejecting film / sheet material onto the pressure roller cross-linking assembly.

[0009] The synthesized polymer melt enters the first extrusion system and undergoes conventional processing (such as devolatilization, cooling, and pressure buildup). A portion of the melt is then transferred to the second extrusion system via a melt transfer device. After entering the second extrusion system, the melt enters the twin-screw extruder. The rotation of the twin screws propels the melt toward the die. Passing through the modifier receiving and mixing section, it mixes with the modifier from the modifier injection device and undergoes intense shear dispersion. The modifier from the modifier injection device is delivered via an injection pipe to the toothed disc twin-screw, which performs the shear dispersion function.

[0010] The melt mixed with the modifier enters the die, where it undergoes an incomplete crosslinking reaction and is extruded into a film (film / sheet material). The film first passes through the pressure roller crosslinking assembly to complete the crosslinking reaction and form the film product of the desired thickness and width before entering the winding mechanism for rewinding.

[0011] Furthermore, the first extrusion system includes a screw pressure building section, a first gear pump and an underwater pelletizing device, the screw pressure building section, the first gear pump, and the underwater pelletizing device are connected in sequence, and the liquid inlet end of the melt transfer device is connected to the pipeline between the first gear pump and the underwater pelletizing device.

[0012] Furthermore, the first extrusion system further comprises a first discharge valve, which is arranged between the first gear valve and the underwater pelletizing device, and is used to discharge the detected unqualified melt out of the first extrusion system; and / or,

[0013] The first extrusion system further includes a screen changer, which is arranged between the first gear and the underwater pelletizing device and is used to filter cross-linked material blocks or carbonized material blocks in the melt;

[0014] The liquid inlet end of the melt transfer device is arranged upstream of the underwater pelletizing device along the direction of travel of the melt and close to the underwater pelletizing device.

[0015] Furthermore, a first discharge valve and a screen changer are sequentially provided between the first gear pump and the underwater pelletizing device along the direction of melt travel, wherein the liquid inlet end of the melt transfer device is connected to the pipeline between the screen changer and the underwater pelletizing device.

[0016] Furthermore, the melt transfer device includes a melt pipe, a buffer hopper, and a second gear pump, which are connected in sequence; wherein, a control valve and a second discharge valve are provided on the melt pipe, and the gear pump is arranged between the buffer hopper and the twin-screw extruder device.

[0017] When the control valve is opened, a portion of the melt from the first extrusion system enters the melt pipe and flows into the buffer hopper. Pressurized by the second gear pump, it then enters the second extrusion system. The second discharge valve, similar to the first, detects and discharges unqualified material in the melt pipe due to oxidation and other factors (such as degradation and yellowing). The buffer hopper maintains a stable melt supply. The control valve regulates melt flow and is linked to the buffer hopper's liquid level. At low levels, the valve opening increases, while at high levels, the valve opening decreases to prevent the melt from remaining in the buffer hopper for extended periods.

[0018] Furthermore, the melt pipe and buffer hopper are both provided with a jacket insulation device for maintaining the fluidity of the melt.

[0019] Furthermore, the modifier receiving and mixing section is arranged near the die head.

[0020] Furthermore, the injection barrel section includes a barrel and a connecting flange structural component, the barrel is configured to have a cylindrical barrel head adapted to the connecting flange, at least one injection tube is provided on the side wall of the cylindrical barrel head, and the connecting flange is configured to have a channel adapted to the injection tube, for the injection tube to extend through the connecting flange to the outside of the twin-screw extruder device.

[0021] Furthermore, four liquid injection pipes are provided on the side wall of the cylindrical barrel head, and four corresponding holes are opened on the side wall of the connecting flange assembly.

[0022] Furthermore, the pressure roller cross-linking assembly includes a front section pressure roller assembly and a rear section pressure roller assembly;

[0023] The front-end roller assembly is used to receive the film / sheet material ejected from the die head and heat and roll the film / sheet material to complete the cross-linking reaction; the rear-end roller assembly is used to cool the film / sheet material that has completed the cross-linking reaction.

[0024] Furthermore, the front-stage pressing roller assembly includes three groups of pressing rollers, and the three groups of pressing rollers are arranged in sequence along the moving direction of the film / sheet material.

[0025] The present application also provides an online modification and combined extrusion method, which uses the above-mentioned equipment, including:

[0026] S1, the melt enters the first extrusion system, after the pressure is increased and before granulation, part of the melt is transferred to the second extrusion system through the melt transfer device, and the melt not transferred in the first extrusion system is extruded and granulated;

[0027] S2, mixing the melt of the second extrusion system with the modifier from the modifier injection device in the modifier receiving and mixing section of the twin-screw extruder, and spraying the film / sheet material through the die head onto the pressure roller cross-linking assembly after mixing and dispersing by the toothed disc twin-screw;

[0028] S3, the film / sheet material is subjected to roller-pressing and heating treatment by the roller cross-linking assembly to complete the cross-linking reaction, and then subjected to roller-pressing and cooling treatment to finally form a modified film and then be rolled up.

[0029] In S1, the pressure-raising treatment method is: the melt pressure is raised to 10-15 MPa by the screw pressure-building section, and then raised to above 20 MPa by the first gear pump. The pressure is reduced to 5-10 MPa before the melt enters the underwater pelletizing device.

[0030] The S2 includes:

[0031] S2-1: The melt is extruded by a twin-screw extruder while maintaining the melt temperature below the cross-linking temperature, and the modifier and the melt are evenly dispersed by the toothed disc twin-screw extruder;

[0032] S2-2: The melt evenly mixed with the modifier enters the die to complete a partial cross-linking reaction, and is extruded through the die to form a film / sheet material.

[0033] Preferably, in S3, the heating temperature of the roller-pressing heating treatment is within the cross-linking reaction temperature range of the film / sheet material, and the film / sheet material ejected from the die head completes all cross-linking reactions during the heating roller-pressing process to obtain a modified adhesive film.

[0034] This application cleverly achieves the simultaneous preparation of granules and modified films through the design of a melt transfer device and a second extrusion system on traditional extrusion granulation equipment, effectively saving process flow and production costs, and ensuring the product quality of the polymer granules and modified films prepared simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings:

[0036] Figure 1 1 is a schematic structural diagram of an online modification and co-extrusion device according to an embodiment of the present application;

[0037] Figure 2 1 is a schematic structural diagram of an online modification and co-extrusion device according to an embodiment of the present application;

[0038] Figure 3 This is a schematic structural diagram of a portion (second extrusion system and rolling system) of an online modified combined extrusion device according to an embodiment of the present application;

[0039] Figure 4 yes Figure 3 A partial enlarged view of middle A;

[0040] Figure 5 This is a schematic exploded perspective view of a liquid injection barrel section in an online modification and combined extrusion device according to one embodiment of the present application;

[0041] Figure 6 This is a schematic cross-sectional view of a liquid injection barrel section located at the installation location of the liquid injection pipe in an online modification combined extrusion device according to one embodiment of the present application;

[0042] Among them, 1: first extrusion system, 2: second extrusion system, 3: melt transfer device, 4: roller pressing system, 11: screw pressure building section, 12: first gear pump, 13: underwater pelletizing device, 14: first discharge valve, 15: screen changer, 21: twin-screw extruder, 22: die head, 23: modifier injection device, 21-1: barrel, 21-2: twin screw, 210: modifier receiving and mixing section, 210-1: injection barrel, 210-2: toothed disc twin screw, 210- 11: Barrel, 210-12: Connecting flange, 210-110: Cylindrical barrel head, 213: Accommodating space, 214: Liquid injection pipe, 215: Channel, 31: Liquid inlet end, 32: Liquid outlet end, 33: Melt pipe, 34: Buffer hopper, 35: Second gear pump, 331: Control valve, 332: Second discharge valve, 41: Pressure roller cross-linking assembly, 42: Winding device, 43: Thickness measuring device, 44: Cutting device, 411: Front section pressure roller assembly, 412: Rear section pressure roller assembly. DETAILED DESCRIPTION

[0043] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0044] In the description of this application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting this application. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly indicate the number of the technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections, or interconnected connections; direct connections or indirect connections through an intermediary; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0046] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact via another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or diagonally above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or diagonally above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0047] The disclosure below provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0048] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application and are not used to limit the present application.

[0049] Example 1:

[0050] like Figure 1-2 As shown, the first embodiment of the present application provides an online modification and extrusion device, which can realize the process of online modification of part of the polymer material and extrusion molding into a film while granulating the polymer material, and obtain different products in granular and film forms at the same time.

[0051] The equipment consists of four major components: a first extrusion system 1, a second extrusion system 2, a melt transfer device 3, and a rolling system 4. The first extrusion system 1 performs the traditional extrusion granulation process to produce granular polymer materials. The melt transfer device 3 in the rolling system 4 transfers a portion of the melt from the first extrusion system 1 to the second extrusion system 2. The second extrusion system 2 is used to chemically modify the polymer material, thereby extruding a cross-linked film / sheet material, which is then further rolled by the rolling system 4 to produce a film product.

[0052] The specific structure of each part is described in detail below.

[0053] First extrusion system 1

[0054] like Figure 1As shown, the first extrusion system 1 includes a screw pressure building section 11, a first gear pump 12 and an underwater pelletizing device 13, and the screw pressure building section 11, the first gear pump 12, and the underwater pelletizing device 13 are connected in sequence. Taking ethylene vinyl acetate (EVA) as an example, the EVA material after the reaction synthesis is sent to the screw pressure building section 11 of the first extrusion system 1 through a feeding device. The structure of the screw pressure building section 11 is a traditional extrusion device with a barrel and a screw, and functional devices such as devolatilization can be added according to the process purpose of the processed material. However, in the present application, the main function of the screw pressure building section 11 is to build pressure, that is, to increase the pressure in the barrel to a preset pressure, in preparation for the online modification of the present application. In order to achieve the purpose of the online modification of the present application, the screw pressure building section 1 can increase the melt pressure to 10-15 Mpa. Driven by such a purpose, those skilled in the art can achieve it by adjusting parameters such as the length of the screw pressure building section 11. The screw pressure building section 11 can adopt a single screw or a twin screw. For the pressure building of EVA, a single screw is generally sufficient. The first gear pump 12 can instantly increase the pressure of the melt to a higher level. The cooperation of the screw pressure building section 11 and the first gear pump 12 lays the foundation for subsequent melt transfer and online modification. The EVA melt that has not been transferred enters the underwater pelletizing device 13 for pelletizing. The underwater pelletizing device is already available in this field and will not be described in detail here.

[0055] like Figure 2 The figure shows a preferred embodiment. A first discharge valve 14 and a screen changer 15 can be optionally installed in the first extrusion system 1, located between the first gear valve 12 and the underwater pelletizing device 13. The first discharge valve 14 is a three-way valve structure, one end connected to the first gear pump 12, one end connected to the underwater pelletizing device 13 (if the screen changer 15 is not present) or the screen changer 15, and the other end, also called the ground terminal, is used to discharge unqualified molten material. In actual production, some degraded or yellowed material may occasionally form. In this case, to ensure product quality, the first discharge valve 14 can be installed or activated. The screen changer 15, located between the first gear 12 (if the first discharge valve 14 is not present) or the first discharge valve 14 and the underwater pelletizing device 13, is used to filter macromolecular materials such as cross-linked or carbonized materials from the melt.

[0056] Second extrusion system 2

[0057] like Figure 1-4 As shown, the second extrusion system 2 includes a twin-screw extruder 21, a die head 22 mounted at the injection end of the twin-screw extruder, and at least one modifier injection device 23 connected to the twin-screw extruder 21. The twin-screw extruder 21 includes a barrel 21-1 and twin screws 21-2, which can rotate within the barrel. The twin-screw extruder 21 has at least one modifier receiving and mixing section 210.

[0058] See also Figure 1 、 5 As shown in Figures 6 and 7, the modifier receiving and mixing section 210 is located downstream along the direction of melt flow and includes an injection barrel 210-1 and a toothed disc twin screw 210-2. The toothed disc twin screw 210-2 is located within the accommodation space 213 of the injection barrel 210-1. The injection barrel 210-1 has at least one injection pipe 214. The modifier injection device 23 is connected to the injection pipe 214. The toothed disc structure of the toothed disc twin screw 210-2 provides a strong shear dispersion effect. The modifier in the modifier injection device 23 enters the injection barrel 210-1 through the injection pipe 214. At this time, the toothed disc twin screw 210-2 rapidly disperses and mixes the melt from the modified extrusion line (i.e., the second extrusion system 2) with the injected modifier in the modifier receiving and mixing section 210. This mixture enters the die 22 to complete a partial cross-linking reaction, and is then extruded from the die into a film / sheet-like adhesive film. The modifier receiving and mixing section 210 is located near the die head. The addition of a modifier to a melt (such as EVA) can easily initiate a crosslinking reaction, increasing viscosity or causing adhesion to the screw or barrel walls, hindering the operation of the twin-screw extruder 21. Placing the modifier receiving and mixing section 210 near the die head 22 ensures that the mixed and dispersed material quickly enters the die head 22.

[0059] like Figure 5 、 6 As shown, the injection barrel section 210-1 includes a barrel 210-11 and a connecting flange 210-12. The barrel 210-11 is configured to have a cylindrical barrel head 210-110 that is compatible with the connecting flange 210-12. Four injection tubes 214 are provided on the sidewall of the cylindrical barrel head 210-110. As a preferred embodiment of the present application, the connecting flange assembly 210-12 is configured to have four channels 215 that are compatible with the injection tubes 214, allowing the injection tubes 214 to extend through the connecting flange 210-12 and out of the twin-screw extruder 21. The four injection pipes 214 are evenly distributed around the barrel 210-11, and the modifier can be injected into the toothed disk screw segment 210-2 at the same time from four directions. One direction is conducive to rapid dispersion, increasing the mixing speed of the modifier and the melt, and reducing the residence time of the modifier and melt mixture on the twin-screw extruder 21. The other direction reduces the possibility of local cross-linking of the modifier and the melt before uniform dispersion.

[0060] Melt transfer device 3

[0061] The melt transfer device 3 has a liquid inlet 31 and a liquid outlet 32. The liquid inlet 31 is connected to the first extrusion system 1, and the liquid outlet 32 ​​is connected to the second extrusion system 2, for transferring part of the melt from the first extrusion system 1 to the second extrusion system 2.

[0062] The liquid inlet 31 is connected to the pipeline between the first gear pump 12 and the underwater pelletizer 13. If the first extrusion system also includes a first discharge valve 14 and / or a screen changer 15, the liquid inlet 31 is located after the first discharge valve 14 and / or the screen changer 15 and before the underwater pelletizer 13. The melt reaches its highest pressure after the action of the first gear pump 12. The process from the first gear pump 12 to the underwater pelletizer 13 is a depressurization process, with the pressure dropping to 5-10 MPa before reaching the underwater pelletizer 13. During this depressurization process, the original extrusion line (first extrusion system 1) diverts some of the melt. This ensures the fluidity and speed of the diverted melt while minimizing interference with the melt flow of the original extrusion line (first extrusion system 1), resulting in smoother and more stable extrusion pelletization.

[0063] The melt transfer device 3 includes a melt pipe 33, a buffer hopper 34, and a second gear pump 35, which are sequentially connected. The liquid inlet 31 is located on the melt pipe 33 and is connected to the first extrusion system 1. The liquid outlet 32 ​​is the outlet of the second gear pump 35 and is connected upstream to the twin-screw extruder 21 of the modified extrusion line (second extrusion system 2).

[0064] The melt pipe 33 is equipped with a control valve 331 and a second discharge valve 332. When the control valve 331 is opened, a portion of the melt from the first extrusion system enters the melt pipe 33 and flows into the buffer hopper 34. The second gear pump 35 then pressurizes the melt and injects it into the second extrusion system 2. The second gear pump 35 also controls the melt flow rate. The second discharge valve 332 functions similarly to the first discharge valve 14, detecting and discharging unqualified material (such as degraded or yellowed material) in the melt pipe 33 due to oxidation and other factors. The buffer hopper 34 is used to maintain a stable melt supply. The control valve 331 controls the melt flow rate and is linked to the liquid level in the buffer hopper 34. When the liquid level is low, the valve opening increases, and when the liquid level is high, the valve opening decreases to prevent the melt from remaining in the buffer hopper 34 for an extended period of time.

[0065] As a more preferred embodiment, the melt pipe 33 and the buffer hopper 34 are both provided with a jacket insulation device for maintaining the fluidity of the melt.

[0066] Roller pressing system 4

[0067] like Figure 3 、 4 As shown, the roller pressing system 4 includes at least one set of roller cross-linking components 41 and a winding device 42. The die head 22 is adapted to the roller cross-linking component 41 and is used to eject film / sheet material onto the roller cross-linking component 41.

[0068] The roller crosslinking assembly 41 comprises a front roller assembly 411 and a rear roller assembly 412. The front roller assembly 411 receives the film / sheet material ejected from the die head and heats and rolls it to complete the crosslinking reaction. The rear roller assembly 412 cools the crosslinked film / sheet material. In a preferred embodiment of this application, the front roller assembly 411 comprises three sets of rollers, arranged sequentially along the direction of travel of the film / sheet material (adhesive film). This allows for more complete crosslinking of the film and allows for precise control of film thickness. The rear roller assembly 412 may also be equipped with a thickness gauge 43. After cooling in the rear roller assembly 412, the film enters the reel 42. To achieve a more uniform product, a cutting device 44 may be provided before reeling to provide a more uniform cut on the film's sides.

[0069] The synthesized polymer material melt enters the first extrusion system 1 and undergoes conventional processing (such as devolatilization, cooling, and pressure buildup). A portion of the melt is then transferred to the second extrusion system 2 via the melt transfer device 3. After entering the second extrusion system 2, the melt enters the twin-screw extruder 21. The rotation of the twin screws propels the melt toward the die. Passing through the modifier receiving and mixing section 210, it mixes with the modifier from the modifier injection device 23 and undergoes intense shear dispersion. The modifier in the modifier injection device 23 is delivered via the injection pipe 214 to the toothed disc twin-screw section, which provides shear dispersion. The modifier-mixed melt enters the die, where it undergoes a partial cross-linking reaction and is extruded into a film (film / sheet material). The film first passes through the roller cross-linking assembly 41, completing the cross-linking reaction and forming a film product of the desired thickness and width before entering the winding mechanism for rewinding.

[0070] Example 2:

[0071] This embodiment proposes an online modification method, which is suitable for online chemical modification during extrusion granulation. The details are as follows:

[0072] A combined granulation and film-forming extrusion method based on online chemical modification, using the above-mentioned equipment, comprising:

[0073] S1, after the melt enters the first extrusion system and is pressurized and before granulation, part of the melt is transferred to the second extrusion system through a melt transfer device, and part of the melt is extruded and granulated;

[0074] S2, mixing and dispersing the partial melt of the second extrusion system and the modifier from the modifier injection device in the modifier receiving and mixing section of the twin-screw extruder through the toothed disc twin-screw, and then ejecting the film / sheet material through the die head onto the pressure roller cross-linking assembly;

[0075] S3, the film / sheet material is subjected to roller-pressing and heating treatment by the roller cross-linking assembly to complete the cross-linking reaction, and then subjected to roller-pressing and cooling treatment to finally form a modified film and then be rolled up.

[0076] The portion of the melt transferred to the second extrusion system accounts for 5wt%-10wt% of the melt entering the first system.

[0077] In S1, the pressure is first increased to 10-15 MPa by the screw pressure building section, and then to above 20 MPa by the gear pump. Before the melt enters the underwater pelletizing device, the pressure is reduced to 5-10 MPa.

[0078] The S2 includes:

[0079] S2-1: The melt is extruded by a twin-screw extruder while maintaining the melt temperature at the cross-linking temperature, and the modifier and the melt are evenly dispersed by the toothed disc twin-screw extruder;

[0080] S2-2: The melt evenly mixed with the modifier enters the die to complete a partial cross-linking reaction, and is extruded through the die to form a film / sheet material.

[0081] In S3, the heating temperature of the roller-pressing heating treatment is within the cross-linking reaction temperature range of the film / sheet material. The film / sheet material ejected from the die head completes all cross-linking reactions during the heating roller-pressing process to obtain a modified adhesive film.

[0082] Finally, it should be noted that the above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An online modified combined extrusion device, characterized in that: include: A first extrusion system, a second extrusion system, a melt transfer device and a roller pressing system; The first extrusion system is used to prepare polymer material particles; the second extrusion system is used to complete the chemical modification of the polymer material by the first extrusion system and extrude a film / sheet material with an incomplete cross-linking reaction; the rolling system is used to complete the complete cross-linking reaction of the film / sheet material formed by the second extrusion system and form a film product of the required thickness and width before winding; The first extrusion system includes a screw pressure building section, a first gear pump, and an underwater pelletizing device, wherein the screw pressure building section, the first gear pump, and the underwater pelletizing device are connected in sequence, and the liquid inlet end of the melt transfer device is connected to the pipeline between the first gear pump and the underwater pelletizing device; The melt transfer device has a liquid inlet end and a liquid outlet end, the liquid inlet end is connected to the underwater pelletizing device of the first extrusion system, and the liquid outlet end is connected to the second extrusion system, and is used to transfer part of the melt of the first extrusion system to the second extrusion system; The second extrusion system includes a twin-screw extruder, a die head installed at the injection end of the twin-screw extruder, and at least one modifier injection device connected to the twin-screw extruder; the twin-screw extruder has at least one set of modifier receiving and mixing sections, the modifier receiving and mixing sections including a liquid injection barrel and a toothed disc twin screw, the toothed disc twin screw being located in the accommodating space of the liquid injection barrel; wherein the liquid injection barrel has at least one liquid injection pipe, the modifier injection device is connected to the liquid injection pipe; the modifier receiving and mixing section is arranged downstream along the direction of melt travel; The roller pressing system includes at least one set of roller cross-linking components and a winding device; Wherein, the die head is adapted to the pressure roller cross-linking assembly and is used for ejecting film / sheet material onto the pressure roller cross-linking assembly; The melt transfer device includes a melt pipe, a buffer hopper, and a second gear pump, which are connected in sequence; wherein the melt pipe is provided with a control valve and a second discharge valve, and the second gear pump is arranged between the buffer hopper and the twin-screw extruder.

2. The online modification combined extrusion equipment according to claim 1, characterized in that: The first extrusion system further includes a first discharge valve, which is arranged between the first gear pump and the underwater pelletizing device, and is used to discharge the detected unqualified melt from the first extrusion system; and / or, The first extrusion system further includes a screen changer, which is arranged between the first gear pump and the underwater pelletizing device and is used to filter cross-linked material blocks or carbonized material blocks in the melt; The liquid inlet end of the melt transfer device is arranged upstream of the underwater pelletizing device along the direction of travel of the melt and close to the underwater pelletizing device.

3. The online modification combined extrusion equipment according to claim 2, characterized in that: A first discharge valve and a screen changer are sequentially provided between the first gear pump and the underwater pelletizing device along the direction of melt travel, wherein the liquid inlet end of the melt transfer device is provided between the screen changer and the underwater pelletizing device.

4. The online modification combined extrusion equipment according to claim 1, characterized in that: The melt pipe and buffer hopper are both provided with jacket insulation devices.

5. The online modification combined extrusion equipment according to claim 1, characterized in that: The modifier receiving and mixing section is arranged near the die head.

6. The online modification combined extrusion equipment according to claim 1, characterized in that: The injection barrel includes a barrel and a connecting flange. The barrel is configured to have a cylindrical barrel head that is compatible with the connecting flange. At least one injection tube is provided on the side wall of the cylindrical barrel head. The connecting flange is configured to have a channel that is compatible with the injection tube, so that the injection tube extends through the connecting flange to the outside of the twin-screw extruder device.

7. The online modification combined extrusion equipment according to claim 6, characterized in that: Four liquid injection pipes are arranged on the side wall of the cylindrical barrel head, and four corresponding holes are opened on the side wall of the connecting flange.

8. The online modification combined extrusion equipment according to claim 1, characterized in that: The pressure roller cross-linking assembly includes a front-section pressure roller assembly and a rear-section pressure roller assembly; The front-end roller assembly is used to receive the film / sheet material ejected from the die head and heat and roll the film / sheet material to complete the cross-linking reaction; the rear-end roller assembly is used to cool the film / sheet material that has completed the cross-linking reaction.

9. The online modification combined extrusion equipment according to claim 8, characterized in that: The front-stage pressing roller assembly includes three groups of pressing rollers, and the three groups of pressing rollers are arranged in sequence along the moving direction of the film / sheet material.

10. A method based on online modification and combined extrusion, characterized in that: The device according to any one of claims 1 to 9 comprises: S1, the melt enters the first extrusion system, after the pressure is increased and before granulation, part of the melt is transferred to the second extrusion system through the melt transfer device, and the melt not transferred in the first extrusion system is extruded and granulated; S2, mixing the melt of the second extrusion system with the modifier from the modifier injection device in the modifier receiving and mixing section of the twin-screw extruder, and spraying the film / sheet material through the die head onto the pressure roller cross-linking assembly after mixing and dispersing by the toothed disc twin-screw; S3, the film / sheet material is subjected to roller-pressing and heating treatment by the roller cross-linking assembly to complete the cross-linking reaction, and then subjected to roller-pressing and cooling treatment to finally form a modified film and then be rolled up.

11. The method according to claim 10, characterized in that The portion of the melt transferred to the second extrusion system accounts for 5wt%-10wt% of the total amount of the melt entering the first system.

12. The method according to claim 10, characterized in that In S1, the method of the pressure-increasing treatment is: increasing the melt pressure to 10-15 MPa through the screw pressure-building section, and then increasing it to above 20 MPa through the first gear pump.

13. The method according to claim 10, characterized in that The pressure of the melt drops to 5-10 MPa before entering the underwater pelletizing device.

14. The method according to claim 10, characterized in that The S2 includes: S2-1: The melt is extruded by a twin-screw extruder while maintaining the melt temperature below the cross-linking temperature, and the modifier and the melt are evenly dispersed by the toothed disc twin-screw extruder; S2-2: The melt evenly mixed with the modifier enters the die to complete a partial cross-linking reaction, and is extruded through the die to form a film / sheet material.

15. The method according to claim 10, characterized in that In S3, the heating temperature of the roller-pressing heating treatment is within the cross-linking reaction temperature range of the film / sheet material. The film / sheet material ejected from the die head completes all cross-linking reactions during the heating roller-pressing process to obtain a modified adhesive film.

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