Equipment and method for producing ABS resin

Abstract

This invention relates to the field of ABS resin material production technology, and provides equipment and method for producing ABS resin, including a twin-screw extruder and at least one side-venting screw extruder. The twin-screw extruder internally houses a mandrel and a screw composed of modular threaded elements mounted on the mandrel. The twin-screw extruder includes at least one venting section. Each venting section is connected to a side-venting screw extruder, which internally houses a screw and is connected to an external suction device. The screw in the side-venting screw extruder rotates towards one side of the twin-screw extruder to apply pressure to the material. By directly connecting the side-venting screw extruder to the twin-screw extruder, the moisture generated during material heating and vaporization can be directly discharged while preventing material from being discharged, effectively preventing material blockage and shutdown.

Description

Technical Field

[0001] This invention relates to the field of ABS resin production technology, and in particular to an equipment and method for producing ABS resin. Background Technology

[0002] ABS plastic is a terpolymer of acrylonitrile (A), butadiene (B), and styrene (S). Its molecular formula can be written as (C8H8·C4H6·C3H3N)x. The relative contents of the three monomers can be varied arbitrarily to make various resins.

[0003] There are currently a few methods for preparing SAN using melt extrusion. The method involves first pumping melt SAN to the inlet of a twin-screw extruder. Then, a side screw feeds in ABS rubber powder for blending and toughening. Because the melt enters the twin-screw extruder first, the ABS rubber powder, containing a certain amount of moisture, rapidly and continuously vaporizes upon encountering the high-temperature melt SAN already present in the extruder, generating a large amount of water vapor. Production verification has shown that this water vapor can block the side screw and backflow along its gaps, severely affecting feeding stability, frequently causing material blockages and shutdowns, greatly hindering production, easily reducing product yield, and failing to achieve the required production quality. Summary of the Invention

[0004] This invention aims to solve at least one of the technical problems existing in related technologies. To this end, this invention proposes an apparatus and method for producing ABS resin, which installs a side-venting screw extruder on a twin-screw extruder, enabling timely steam discharge, preventing material blockage and shutdown, and increasing product output.

[0005] An apparatus for producing ABS resin according to an embodiment of the present invention includes: a twin-screw extruder and at least one side-venting screw extruder;

[0006] The twin-screw extruder is internally equipped with a mandrel and a screw consisting of modular threaded elements mounted on the mandrel. The twin-screw extruder includes at least one venting section.

[0007] The at least one exhaust section is respectively connected to a side exhaust screw compressor, and the side exhaust screw compressor is provided with a screw inside;

[0008] The screw in the side-venting screw extruder rotates toward one side of the twin-screw extruder to apply pressure to the material toward one side of the twin-screw extruder.

[0009] According to an embodiment of the present invention, in the equipment for producing ABS resin, the exhaust section is provided with an exhaust port, and the side-exhaust screw extruder is connected to the twin-screw extruder through the exhaust port.

[0010] According to an embodiment of the present invention, the twin-screw extruder for producing ABS resin further includes: a feeding conveying zone, a plasticizing and mixing zone, and a pressure building zone;

[0011] The feeding and conveying zone, the plasticizing and mixing zone, the at least one exhaust section, and the pressure building section are connected in sequence.

[0012] According to an embodiment of the present invention, the equipment for producing ABS resin includes a feeding and conveying zone composed of a first cylinder, a second cylinder, and a third cylinder connected in sequence.

[0013] The first cylinder is provided with a first feeding port, which is used to feed ABS rubber powder and other materials to be processed.

[0014] The third cylinder is provided with a second feeding port, which is used to feed molten SAN.

[0015] According to an embodiment of the ABS resin production apparatus, the length of the second cylinder is: Where D is the diameter of the threaded element of the twin-screw extruder.

[0016] According to an embodiment of the present invention, in the equipment for producing ABS resin, the lead of the thread of the corresponding mandrel in the second cylinder gradually decreases, and the ratio of the maximum lead to the minimum lead, i.e., the compression ratio, is not less than 1.5.

[0017] According to an embodiment of the present invention, in the equipment for producing ABS resin, the plasticizing and mixing zone is composed of a plurality of cylinders connected in sequence.

[0018] According to an embodiment of the present invention, in an apparatus for producing ABS resin, the exhaust section is composed of a front section and a rear section connected in sequence;

[0019] The front section is provided with an injection port, which can be used to add materials that aid in the devolution process;

[0020] The exhaust port is located on the rear section.

[0021] According to an embodiment of the present invention, the equipment for producing ABS resin includes, but is not limited to, a devolition aid water, wherein the amount of the devolition aid water is 0.4 wt% to 0.6 wt% of the ABS resin production and the water temperature does not exceed 60°C.

[0022] In the ABS resin production apparatus according to an embodiment of the present invention, the length of the exhaust section is: Where D is the diameter of the threaded element of the twin-screw extruder.

[0023] According to an embodiment of the ABS resin production equipment, the length of the pressure-building section is: Where D is the diameter of the threaded element of the twin-screw extruder.

[0024] According to an embodiment of the present invention, in an apparatus for producing ABS resin, the threaded element includes a feed thread and a shearing thread;

[0025] The conveying thread is provided in the feeding conveying area, the rear section of the venting section, and the pressure building section;

[0026] The shearing thread is located in the plasticizing and mixing zone and the front section of the exhaust section. The shearing thread is used to shear and mix the materials.

[0027] According to an embodiment of the present invention, the equipment for producing ABS resin includes, but is not limited to, ABS rubber powder, melt SAN, production aids, recycled ABS particles, or recycled SAN.

[0028] According to an embodiment of the present invention, in the equipment for producing ABS resin, the moisture content of the ABS rubber powder particles does not exceed 20 wt%.

[0029] In the ABS resin production equipment according to an embodiment of the present invention, the amount of recycled ABS particles and recycled SAN re-mixed does not exceed 20%.

[0030] A method for producing ABS resin according to an embodiment of the present invention, based on any one of the apparatuses for producing ABS resin, includes:

[0031] S1: Add ABS rubber granules with a moisture content of no more than 20wt% and other materials to be processed into a twin-screw extruder, and after advancing at least a first distance, mix with the melt SAN added to the screw extruder to obtain a first mixed material;

[0032] The propulsion process mixes and compacts the materials; the first distance Where D is the diameter of the threaded element of the twin-screw extruder;

[0033] S2: The first mixed material is heated and vented to obtain ABS resin.

[0034] According to an embodiment of the present invention, a method for producing ABS resin, and a method for preparing the first mixed material, step S1 includes:

[0035] S11: ABS rubber granules with a moisture content not exceeding 20wt% and other materials to be processed are fed into the first cylinder of the feeding and conveying area through the first feeding port;

[0036] S12: ABS rubber granules with a moisture content not exceeding 20wt% and other materials to be processed are conveyed from the second cylinder to the third cylinder;

[0037] S13: The melt SAN is fed into the third cylinder through the second feed port, and is transported to the plasticizing and mixing zone along with the ABS rubber granules and other materials to be processed. The mixture is then uniformly mixed by shearing to obtain the first mixed material.

[0038] The method for producing ABS resin according to an embodiment of the present invention, wherein step S2 further includes:

[0039] The first mixture is connected to a vacuum system in the exhaust section. External heating and shear heat generation are used to evaporate the moisture in the first mixture and discharge the steam through the side exhaust screw to obtain ABS resin. At the same time, the screw of the side exhaust screw sends the first mixture carried out in the steam back to the exhaust section.

[0040] According to an embodiment of the present invention, in the method for producing ABS resin, the vacuum system pressure is 0 kPaA - 100 kPaA.

[0041] According to the method for producing ABS resin according to an embodiment of the present invention, the devolatilization aid material includes, but is not limited to, devolatilization aid water, wherein the amount of devolatilization aid water is 0.4 wt% to 0.6 wt% of the ABS resin production and the water temperature does not exceed 60°C.

[0042] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0043] One embodiment of the present invention provides an apparatus and method for producing ABS resin, comprising a twin-screw extruder and at least one side-venting screw extruder; the twin-screw extruder internally comprises a mandrel and a screw consisting of modular threaded elements mounted on the mandrel, and includes at least one venting section; each of the at least one venting section is connected to a side-venting screw extruder, the side-venting screw extruder internally comprising a screw, and the side-venting screw extruder is connected to an external suction device for discharging moisture from the processed material within the twin-screw extruder through the venting section and the side-venting screw extruder; the screw in the side-venting screw extruder rotates toward one side of the twin-screw extruder to apply pressure to the material toward one side of the twin-screw extruder. By directly connecting the side-venting screw extruder to the twin-screw extruder, the moisture in the material heated and vaporized into steam can be directly discharged while preventing the material from being discharged, effectively preventing material blockage and shutdown;

[0044] Another embodiment of the present invention provides a method for producing ABS resin, comprising: S1: adding ABS rubber granules with a water content not exceeding 20 wt% and other materials to be processed into a screw extruder, and advancing them at least a first distance before mixing them with molten SAN added to the screw extruder to obtain a first mixed material; S2: heating and venting the first mixed material to obtain ABS resin. Using molten SAN directly as a raw material to produce ABS resin reduces the process of SAN granulation and remelting, thereby reducing power consumption and the process of molten SAN granulation and remelting, thus reducing equipment investment and operational control processes.

[0045] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 These are the front view and partial sectional view of the equipment for producing ABS resin provided in the embodiments of the present invention;

[0048] Figure 2 These are top views and partial sectional views of the equipment for producing ABS resin provided in the embodiments of the present invention;

[0049] Figure 3 This is a comparison chart of different numerical proportions of the ABS resin production method provided in the embodiments of the present invention;

[0050] Figure 4 yes Figure 1 A schematic diagram of the lead of the screw in the first to third screw sections.

[0051] Figure label:

[0052] 100. Twin-screw extruder; 110. Feeding and conveying zone; 111. First barrel; 111-1. First screw section; 111-2. First feed port; 112. Second barrel; 112-1. Second screw section; 113. Third barrel; 113-1. Third screw section; 113-2. Second feed port; 120. Plasticizing and mixing zone; 121. Fourth barrel; 121-1. Fourth screw section; 122. Fifth barrel; 122-1. Fifth screw section; 130. First venting section; 131. Front section of the first venting section; 131-1. Sixth screw section; 131-2. First vent port; 132. Rear section of the first venting section; 132-1. Seventh screw section; 140. Second venting section; 141. The front section of the second exhaust section; 141-1, the eighth screw section; 141-2, the first injection port; 142, the rear section of the second exhaust section; 142-1, the ninth screw section; 142-2, the second exhaust port; 150, the third exhaust section; 151, the front section of the third exhaust section; 151-1, the tenth screw section; 151-2, the second injection port; 152, the rear section of the third exhaust section; 152-1, the eleventh screw section; 152-2, the third exhaust port; 160, the pressure build-up section; 160-1, the twelfth screw section; 170, the motor; 180, the coupling; 190, the gearbox; 200, the side exhaust screw compressor; 201, the first side exhaust screw compressor; 202, the second side exhaust screw compressor; 203, the third side exhaust screw compressor. Detailed Implementation

[0053] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0054] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention 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. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0055] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0056] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is 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 can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0057] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0058] This invention provides an apparatus for producing ABS resin. The design and application of this equipment primarily focus on the field of ABS resin production technology, aiming to optimize the production process and improve production efficiency. In the traditional ABS resin production process, moisture control has always been a critical step, as moisture can not only affect resin quality but also lead to a decrease in production efficiency. To effectively solve this problem, this invention creatively employs a linkage mechanism between a side-venting screw extruder and a twin-screw extruder. This mechanism can directly vaporize the moisture generated during production into water vapor through heating, and then directly discharge it through a specific exhaust system, thereby effectively avoiding the potential impact of moisture on resin quality and significantly improving the continuity and stability of the production line. This invention also provides a method for producing ABS resin, directly adding molten ABS as raw material to the twin-screw extruder, instead of the traditional step of first preparing SAN granules and then performing melt processing. This change not only simplifies the entire production process, reduces intermediate steps and energy consumption, but also makes the equipment more efficient and flexible in its use. Since molten ABS enters the extruder directly without any additional pretreatment steps, the production cycle can be significantly shortened and production efficiency improved. The design of the side-venting screw compressor is determined by the number of venting sections designed for the twin-screw extruder. When the moisture content of the feed to the twin-screw extruder is too high, multiple side-venting screw compressors can be installed to vent the ABS resin and achieve the desired ABS resin production.

[0059] One embodiment of the present invention, in conjunction with Figure 1 and Figure 2 As shown in the embodiment of the present invention, an apparatus for producing ABS resin is provided, including a twin-screw extruder 100 and at least one side-venting screw extruder 200. The twin-screw extruder 100 internally comprises a mandrel and a screw consisting of modular threaded elements mounted on the mandrel. The twin-screw extruder 100 includes at least one venting section, with vent ports externally located. Each vent port is connected to the side-venting screw extruder 200, which is connected to a motor capable of driving the side-venting screw extruder 200. A screw is internally located within the side-venting screw extruder 200. The side-venting screw extruder 200 can be connected to an external extraction device to remove moisture from the processed material within the twin-screw extruder 100. The screw in the side-venting screw extruder 200 rotates towards one side of the twin-screw extruder 100 to apply pressure to the material towards that side, preventing the extraction device from carrying away both steam and material simultaneously.

[0060] In this embodiment, the twin-screw extruder 100 includes: a feeding and conveying zone 110, a plasticizing and mixing zone 120, a first venting section 130, a second venting section 140, a third venting section 150, and a pressure building section 160, and the feeding and conveying zone 110, the plasticizing and mixing zone 120, the first venting section 130, the second venting section 140, the third venting section 150, and the pressure building section 160 are connected in sequence. The side-exhaust screw compressor 200 includes: a first side-exhaust screw compressor 201, a second side-exhaust screw compressor 202, and a third side-exhaust screw compressor 203. The first side-exhaust screw compressor 201 is connected to the first exhaust section 130, the second side-exhaust screw compressor 202 is connected to the second exhaust section 140, and the third side-exhaust screw compressor 203 is connected to the third exhaust section 150. The first side-exhaust screw compressor 201, the second side-exhaust screw compressor 202, and the third side-exhaust screw compressor 203 are respectively used to discharge the water that has been heated, vaporized, and evaporated into steam in the first exhaust section 130, the second exhaust section 140, and the third exhaust section 150.

[0061] It is understood that the twin-screw extruder 100 is a co-rotating twin-screw extruder with two screws meshing to form a figure-eight shape. In this embodiment, the twin screws can transport, melt, plasticize, and shear compounded materials.

[0062] In this embodiment, the feeding and conveying zone 110 is composed of a first cylinder 111, a second cylinder 112, and a third cylinder 113 connected in sequence. The first cylinder 111 has a first feeding port 111-2, which is used to feed the material to be processed. The third cylinder 113 has a second feeding port 113-2, which is used to feed the melt SAN. A first screw section 111-1, a second screw section 112-1, and a third screw section 113-1 are arranged outside the mandrel of the feeding and conveying zone 110. The first screw section 111-1, the second screw section 112-1, and the third screw section 113-1 correspond to the first cylinder 111, the second cylinder 112, and the third cylinder 113, respectively.

[0063] The plasticizing and mixing zone 120 is composed of a fourth cylinder 121 and a fifth cylinder 122 connected in sequence. A fourth screw section 121-1 and a fifth screw section 122-1 are provided outside the mandrel of the plasticizing and mixing zone 120. The fourth screw section 121-1 and the fifth screw section 122-1 correspond to the fourth cylinder 121 and the fifth cylinder 122, respectively.

[0064] The first exhaust section 130 is composed of a front section 131 and a rear section 132 connected in sequence. The front section 131 of the first exhaust section has a first exhaust port 131-2, and the first exhaust port 131-2 is connected to the first side exhaust screw machine 201. A sixth screw section 131-1 and a seventh screw section 132-1 are provided outside the spindle of the first exhaust section 130. The sixth screw section 131-1 and the seventh screw section 132-1 correspond to the front section 131 and the rear section 132 of the first exhaust section, respectively.

[0065] The second exhaust section 140 is composed of a front section 141 and a rear section 142 connected in sequence. The front section 141 of the second exhaust section has a first injection port 141-2 for adding adsorption material. The rear section 142 of the second exhaust section has a second exhaust port 142-2 connected to the second side exhaust screw compressor 202. An eighth screw section 141-1 and a ninth screw section 142-1 are provided outside the spindle of the second exhaust section 140. The eighth screw section 141-1 and the ninth screw section 142-1 correspond to the front section 141 of the second exhaust section and the rear section 142 of the second exhaust section, respectively.

[0066] The third exhaust section 150 is composed of a front section 151 and a rear section 152 connected in sequence. The front section 151 of the third exhaust section has two injection ports 151-2, which are used to add materials to aid in the devolvation process. The rear section 152 of the third exhaust section has a third exhaust port 152-2, which is connected to the third side exhaust screw compressor 203. A tenth screw section 151-1 and an eleventh screw section 152-1 are provided outside the spindle of the third exhaust section 150. The tenth screw section 151-1 and the eleventh screw section 152-1 correspond to the front section 151 and the rear section 152 of the third exhaust section, respectively.

[0067] The mandrel of the pressure building section 160 is provided with an eleventh screw section 160-1.

[0068] The screw section outside the mandrel is equipped with conveying threads and shearing threads. The first screw section 111-1, the second screw section 112-1, and the third screw section 113-1 in the feeding conveying zone 110 are conveying threads, used to mix and convey materials to the plasticizing mixing zone 120. The fourth screw section 121-1 and the fifth screw section 122-1 in the plasticizing mixing zone 120 are shearing threads, used to chop the materials for easier blending and to obtain the first mixed material. The sixth screw section 131-1 and the seventh screw section 132-1 in the first venting section 130 are conveying threads, used to convey the first mixed material to the second venting section 140 to obtain the second mixed material. The second venting section 140... The eighth screw section 141-1 of the 40 is a shearing thread, which is used to shear and mix the second mixture and the adjuvant material added to the second exhaust section 140 to obtain the third mixture; the ninth screw section 142-1 of the second exhaust section 140 is a conveying thread, which is used to convey the third mixture to the third exhaust section 150; the tenth screw section 151-1 of the third exhaust section 150 is a shearing thread, which is used to shear and mix the third mixture and the adjuvant material added to the third exhaust section 150 to obtain the fourth mixture; the eleventh screw section 152-1 of the third exhaust section 150 is a conveying thread, which is used to convey the fourth mixture to the pressure building section 160.

[0069] In this embodiment, the length of the second cylinder 112 is: Where D is the thread diameter of the twin-screw extruder, preferably (4~6)*D; the length of the first venting section 130 is: The preferred value is (6~8)*D; the length of the second exhaust section 140 is: The preferred value is (6~8)*D; the length of the third exhaust section 150 is: The preferred value is (6~8)*D; the length of the pressure-building section 160 is: The preferred value is (4~8)*D. Preferably, the added materials include, but are not limited to, ABS rubber powder, production aids, recycled ABS particles, or recycled SAN. The production aids are powder-based additives; recycled ABS particles or recycled SAN are added as needed, and are not required if no remixing is needed.

[0070] Please see Figure 4As shown, the lead of the screw element gradually decreases from the first screw section 111-1 to the second screw section 112-1. The second screw section 112-1 generates extrusion force on the material to compact it and prevent water vapor from flowing back to the first feed port through the loose material, thus hindering feeding. The lead of the screw thread element is at its minimum at the connection between the second screw section 112-1 and the third screw section 113-1. This setting can prevent ABS powder from splashing and can compact the powder material to fully mix with the molten SAN.

[0071] In this embodiment, the twin-screw extruder 100 is provided with several side openings. When the twin-screw extruder 100 is working, the side-venting screw 200 can directly discharge the water vapor generated by heating and vaporizing during the production process according to the processing sequence, thereby avoiding water vapor clogging the air passage and causing the machine to stop, and improving production output.

[0072] The first exhaust port 131-2 is connected to the first side exhaust screw compressor 201, the first injection port 141-2 is used to add the devolvation aid material, the second exhaust port 142-2 is connected to the second side exhaust screw compressor 202, the second injection port 151-2 is used to add the devolvation aid material, and the third exhaust port 152-2 is connected to the third side exhaust screw compressor 203.

[0073] More preferably, the side-venting screw compressor 200 is connected to a motor, which drives the side-venting screw compressor 200 to rotate in the direction of the twin-screw extruder 100. When material enters the side-venting screw compressor 200, the screw inside the side-venting screw compressor 200 exerts pressure on the material in the direction of the twin-screw extruder 100. At this time, steam is discharged from the side-venting screw compressor 200, and the material can return to the twin-screw extruder 100 along the screw movement direction of the side-venting screw compressor 200, preventing material overflow, ensuring production stability, and improving output and product quality.

[0074] Another embodiment of the present invention provides a method for producing ABS resin, comprising:

[0075] S1: Add ABS rubber granules with a moisture content of no more than 20wt% and other materials to be processed into a twin-screw extruder 100, and after advancing at least a first distance, mix with the melt SAN added to the screw extruder to obtain a first mixed material;

[0076] The propulsion process mixes and compacts the materials; the first distance Where D is the thread diameter of the twin-screw extruder 100;

[0077] S2: The first mixed material is heated and vented to obtain ABS resin.

[0078] Specifically, step S1 also includes:

[0079] S11: ABS rubber granules with a moisture content not exceeding 20wt% and other materials to be processed are fed into the first cylinder 111 of the feeding and conveying area 110 through the first feeding port 111-2;

[0080] S12: ABS rubber granules with a moisture content not exceeding 20wt% and other materials to be processed are conveyed through the second cylinder 112 to the third cylinder 113;

[0081] S13: The melt SAN is fed into the third cylinder 113 through the second feed port 113-2, and is transported to the plasticizing and mixing zone 120 with the ABS rubber powder and other materials to be processed to obtain the first mixed material.

[0082] Specifically, step S2 also includes:

[0083] The first mixture is heated in the exhaust section to evaporate the moisture in the first mixture and the steam is discharged through the side exhaust screw 200 to obtain ABS resin. At the same time, the screw of the side exhaust screw 200 sends the first mixture carried out in the steam back to the exhaust section.

[0084] The materials to be processed include, but are not limited to, production aids, recycled ABS particles, or recycled SAN; the devolvation aid material includes, but is not limited to, devolvation aid water, wherein the amount of water injected is 0.4 wt% to 0.6 wt% of the ABS resin production and the water temperature does not exceed 60°C.

[0085] In this embodiment, the steam discharge in step S2 includes: the first exhaust section 130 discharges steam through the first side exhaust screw compressor 201 to obtain the second mixed material;

[0086] The second exhaust section 140 adds the devolatilization aid material through the first injection port 141-2. The second mixed material and the devolatilization aid material are mixed through the shearing thread of the front section 141 of the second exhaust section. The second side exhaust screw compressor 202 discharges steam to obtain the third mixed material.

[0087] The third exhaust section 150 adds the devolatilization aid material through the second injection port 151-2. The third mixed material and the devolatilization aid material are mixed through the shearing thread of the front section 151 of the third exhaust section. The third side exhaust screw compressor 203 discharges steam to obtain ABS resin and conveys the ABS resin to the pressure building section 160 through the conveying thread.

[0088] In this embodiment, ABS rubber powder is added to the twin-screw extruder 100 through the first feed port 111-2. After being compressed by the second screw section 112-1, it is conveyed to the third barrel 113. Molten SAN is fed into the second feed port 113-2. Through the conveying and plasticizing mixing zone 120 of the third screw section 113-1, ABS rubber powder with a moisture content of up to 20 wt% can be used.

[0089] More preferably, when re-blending is required, recycled SAN or recycled ABS particles can be added, with a maximum re-blending amount of up to 20% of the total production.

[0090] In this embodiment, the devolatilization aid material includes, but is not limited to, devolatilization aid water. The weight ratio and temperature of the devolatilization aid water both affect the residual monomer content of the final ABS resin. The best effect is achieved when the water injection amount is 0.4wt%~0.6wt% of the total ABS resin production and the water temperature is 50℃~60℃.

[0091] Those skilled in the art will understand that when molten SAN is added, the contact between the ABS rubber powder and the molten SAN will generate a large amount of steam that flows back to the feed port. This steam can cause powder agglomeration, pipe blockage, condensation, and other feeding problems at the feed port. However, the method for producing ABS resin provided in this invention utilizes ABS rubber powder first, followed by molten SAN, and employs a screw with a high lead and compression ratio to compact the ABS rubber powder. In this method, the feeding of ABS rubber powder prevents steam from returning to the feed port and causing blockage and shutdown, thus keeping the first feed port 111-2 dry and cooled. The length requirement for the second cylinder 112 in this method is... Where D is the thread diameter of the twin-screw extruder, and considering both economic efficiency and process requirements, the optimal choice is... This method also avoids further processing of the molten SAN, simplifying the process steps.

[0092] The moisture content of the ABS rubber powder fed from the first feeding port 113-2 can be between 0 wt% and 20 wt%.

[0093] In this embodiment, the plasticizing and mixing zone 120 completely plasticizes and mixes the ABS rubber powder with the molten SAN. At this time, there must be no unmelted solid matter at the outlet of the plasticizing and mixing zone 120. When the first feed port 113-2 simultaneously feeds recycled SAN or production additives, a maximum of 20wt% of the total ABS resin production can be recycled.

[0094] In this embodiment, the first exhaust section 130 is mainly used to discharge the steam generated by the vaporization of water contained in the raw material, and to keep the raw material inside the twin-screw extruder 100 without it being ejected. A first exhaust port 131-2 with a side opening is designed at the front section 131 of the first exhaust section 130, and works in conjunction with the first side screw exhauster 201 to discharge the steam and prevent the material from being carried out. The pipeline connected to the first side screw exhauster 201 uses an extraction device to continuously remove the steam. The extraction device includes, but is not limited to, a vacuum system, and the extraction method includes, but is not limited to, vacuum suction or blower suction. Depending on the exhaust volume, the first vacuum can be freely adjusted between 0 kPaA and 100 kPaA. At the rear section 132 of the first exhaust section 130, the material is continuously refreshed, and the water in the raw material continues to vaporize and be discharged. The specific location and number of the first side screw exhausters 201 connected to the first exhaust section 130 are not limited; in some cases, non-exhaust methods can be used for venting. At this point, the length of the first exhaust section 130 is: Where D is the thread diameter of the twin-screw extruder, and more preferably, .

[0095] In this embodiment, the second exhaust section 140 is mainly used to discharge the remaining water vapor and residual small molecule monomers in the raw materials after passing through the first exhaust section 130. Utilizing the principle of foaming devolatilization, a devolatilization aid water is injected into the front section 141 of the second exhaust section 140. The best effect is achieved when the water injection volume is 0.4~0.6 wt% of the total ABS resin production and the water temperature is 50~60℃. The devolatilization aid can also be small molecule substances such as nitrogen and carbon dioxide that do not participate in the reaction and are easily vaporized. After water injection, it is fully mixed with the molten ABS resin. The second exhaust port 142 of the second exhaust section 140 is designed with a side opening and works in conjunction with the second side screw exhaust fan 202 to discharge the steam and prevent the material from being carried out. The pipeline connecting the second-side screw exhaust fan 202 uses vacuum suction to continuously remove steam. The second vacuum can be freely adjusted between 0 kPaA and 50 kPaA depending on the exhaust volume. The specific location and number of the second-side screw exhaust fans 202 in the second exhaust section 140 are not limited; in some cases, non-exhaust fans can also be used for exhaust. The length of the second exhaust section is: Where D is the thread diameter of the twin-screw extruder, and more preferably, .

[0096] In this embodiment, the third exhaust section 150 is mainly used to discharge the water remaining after passing through the second exhaust section 140 and the residual small molecule monomers in the raw materials. Utilizing the principle of foaming devolatilization, a devolatilization aid water is injected into the front section 151 of the third exhaust section of the second exhaust section 140. The best effect is achieved when the water injection volume is 0.4wt%~0.6wt% of the total ABS resin production and the water temperature is 50~60℃. The devolatilization aid can also be small molecule substances such as nitrogen and carbon dioxide that do not participate in the reaction and are easily vaporized. After water injection, it is fully mixed with the molten ABS resin. The third exhaust port 152 of the third exhaust section 150 is designed with a side opening and works in conjunction with the third side screw exhaust fan 203 to discharge steam and prevent material from being carried out. The pipeline connecting the third-side screw exhaust fan 203 uses vacuum suction to continuously remove steam. The third vacuum can be freely adjusted between 0 kPaA and 20 kPaA depending on the exhaust volume. The specific location and number of the third-side screw exhaust fans 203 in the third exhaust section 150 are not limited; in some cases, non-exhaust fans can also be used for exhaust. The length of the third exhaust section 150 is: Where D is the screw diameter of the twin-screw extruder, and more preferably, .

[0097] In this embodiment, the pressure-building section 160 pushes the mixed and degassed ABS resin melt to the downstream pressurization, filtration, and granulation equipment. The length of the pressure-building section is: Where D is the thread diameter of the twin-screw extruder, more preferably, .

[0098] Among them, the front section 131 of the first exhaust section, the rear section 142 of the second exhaust section, and the rear section 152 of the third exhaust section are heated to increase the temperature. The temperature of the front section 131 of the first exhaust section can reach 220-300℃, and the temperature of the rear section 142 of the second exhaust section and the rear section 152 of the third exhaust section increases by 20-30℃ respectively.

[0099] Please see Figure 3 As shown, other embodiments of the present invention produce ABS resin by adding different proportions of re-doped SAN particles, including:

[0100] Step 1: Using a weighing metering device, SAN particles are continuously and stably fed into the second feed port 113-2 of the twin-screw extruder 100 after being completely melted by a melting device, according to the total formula ratio of 74%, 64%, and 54% (corresponding to 0%, 10%, and 20% of recycled SAN particles).

[0101] Step 2: Using a weighing meter, ABS wet powder containing 18% moisture, production aids, and re-blended SAN particles are continuously and stably fed into the first feed port 111-2 of the twin-screw extruder 100 at a total formula ratio of 25% (dry weight): 1%: 0%, 10%, and 20%. The material is conveyed and compressed through the first screw section 111-1 and the second screw section 112-1 in the first barrel 111 and the second barrel 112, and then enters the third barrel 113 to begin mixing with the SAN melt 2.

[0102] Step 3: SAN melt, ABS wet powder with 18% moisture, production aids, and SAN particles are introduced into the plasticizing and mixing zone 120. The components are initially mixed in the fourth cylinder 121 and the fifth cylinder 122 and the fourth screw section 121-1 and the fifth screw section 122-1 inside to obtain a preliminary ABS melt containing more moisture.

[0103] Step 4: The ABS melt containing a large amount of moisture continues to be fed into the first exhaust section 130, passing through the front section 131 and the rear section 132 of the first exhaust section. The ABS melt is efficiently refurbished by the sixth screw section 131-1 and the seventh screw section 132-1, which refurbishes the internal moisture and residual monomers to the surface of the melt and then vaporizes them into steam. The steam enters the first side exhaust screw compressor 201 through the first exhaust port 131-2 located on the front section 131 of the first exhaust section, and is then removed by the vacuum equipment at a vacuum pressure of 100 kPaA. At this point, most of the moisture is separated.

[0104] Step 5: The ABS melt continues to be fed from the seventh screw section 132-1 to the second exhaust section 140. In the front section 141 of the second exhaust section 140, the eighth screw section 141-1 continues to mix the ABS melt. At the same time, water as a de-volatile agent can be injected at the first injection port 141-2 of the front section 141 of the second exhaust section. The water temperature is 55℃ and the injection flow rate is 0.5% of the total output. The water is injected into the eighth screw section 141-1 and fully mixed with the ABS melt. In the rear section 142 of the second exhaust section 140, the ninth screw section 142-1 efficiently renovates the ABS melt, bringing the internal moisture and residual monomers to the surface of the melt and vaporizing them into steam. The steam enters the second side exhaust screw compressor 202 through the second exhaust port 142-2 located in the rear section 142 of the second exhaust section and is removed by a vacuum device at a vacuum pressure of 10 kPaA. The remaining moisture and residual monomers are separated here.

[0105] Step 6: The ABS melt continues to be fed from the ninth screw section 142-1 to the third exhaust section 150. In the front section 151 of the third exhaust section 150, the tenth screw section 151-1 continues to mix the ABS melt. At the same time, water as a de-volatile agent can be injected at the second injection port 151-2 of the front section 151 of the third exhaust section. The water temperature is 55℃ and the injection flow rate is 0.5% of the total output. The water is injected into the tenth screw section 151-1 and fully mixed with the ABS melt. In the rear section 152 of the third exhaust section, the eleventh screw section 152-1 efficiently renews the ABS melt, bringing the internal moisture and residual monomers to the surface of the melt and vaporizing them into steam. The steam enters the second side exhaust screw compressor 202 through the third exhaust port 152-2 on the rear section 152 of the third exhaust section and is removed by a vacuum device at a vacuum pressure of 10 kPaA. At this point, all moisture and residual monomers are separated.

[0106] Step 7: The pure ABS melt is pushed from the eleventh screw section 152-1 to the pressure building section 160. Through the pressure building section 160 and the internal twelfth screw section 160-1, the pure ABS melt is conveyed and pressurized, so that the material can smoothly enter the downstream pelletizing device and finally produce ABS resin with excellent comprehensive performance.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of this application.

Claims

1. A method for producing ABS resin, characterized in that, Based on the equipment for producing ABS resin, the equipment for producing ABS resin includes: a twin-screw extruder and at least one side-venting screw extruder; The twin-screw extruder is internally equipped with a mandrel and a screw consisting of modular threaded elements mounted on the mandrel. The twin-screw extruder includes at least one venting section. The at least one exhaust section is respectively connected to a side exhaust screw compressor, and the side exhaust screw compressor is provided with a screw inside; The screw in the side-venting screw extruder rotates toward one side of the twin-screw extruder, and the screw is used to apply pressure to the material toward one side of the twin-screw extruder; The twin-screw extruder also includes: a feeding conveying zone, a plasticizing and mixing zone, and a pressure building zone; The feeding conveying zone, the plasticizing and mixing zone, the at least one exhaust section, and the pressure building section are connected in sequence; The feeding and conveying area is composed of a first cylinder, a second cylinder, and a third cylinder connected in sequence; The first cylinder is provided with a first feeding port, which is used to feed ABS rubber powder and other materials to be processed. The third cylinder is provided with a second feeding port, which is used to feed molten SAN. The length of the second cylinder is: Where D is the diameter of the threaded element of the twin-screw extruder; The lead of the thread of the corresponding mandrel in the second cylinder gradually decreases, and the ratio of the maximum lead to the minimum lead, i.e., the compression ratio, is not less than 1.

5. The method includes: S1: Add ABS rubber granules with a moisture content of no more than 20wt% and other materials to be processed into a twin-screw extruder, and after advancing at least a first distance, mix with the melt SAN added to the screw extruder to obtain a first mixed material; S11: ABS rubber granules with a moisture content not exceeding 20wt% and other materials to be processed are fed into the first cylinder of the feeding and conveying area through the first feeding port; S12: ABS rubber granules with a moisture content not exceeding 20wt% and other materials to be processed are conveyed from the second cylinder to the third cylinder; S13: The melt SAN is fed into the third cylinder through the second feed port, and is transported to the plasticizing and mixing zone along with the ABS rubber granules and other materials to be processed. The mixture is then uniformly mixed by shearing to obtain the first mixed material. The propulsion process mixes and compacts the materials; the first distance Where D is the diameter of the threaded element of the twin-screw extruder; S2: The first mixed material is heated and vented to obtain ABS resin; the first mixed material is connected to a vacuum system in the venting section, and the water in the first mixed material is evaporated by external heating and shear heat generation and the steam is discharged through the side venting screw to obtain ABS resin. At the same time, the screw of the side venting screw sends the first mixed material carried out in the steam back to the venting section.

2. The method for producing ABS resin according to claim 1, characterized in that, The exhaust section is provided with an exhaust port, and the side-exhaust screw extruder is connected to the twin-screw extruder through the exhaust port.

3. The method for producing ABS resin according to claim 1, characterized in that, The plasticizing and mixing zone is composed of several cylinders connected in sequence.

4. The method for producing ABS resin according to claim 2, characterized in that, The exhaust section is composed of a front section and a rear section connected in sequence; The front section is provided with an injection port, which can be used to add materials that aid in the devolution process; The exhaust port is located on the rear section.

5. The method for producing ABS resin according to claim 4, characterized in that, The devolatilization aid material includes, but is not limited to, devolatilization aid water. The amount of the devolatilization aid water is 0.4 wt% to 0.6 wt% of the ABS resin production and the water temperature does not exceed 60°C.

6. The method for producing ABS resin according to claim 1, characterized in that, The length of the exhaust section is: Where D is the diameter of the threaded element of the twin-screw extruder.

7. The method for producing ABS resin according to claim 1, characterized in that, The length of the pressure-building section is: Where D is the diameter of the threaded element of the twin-screw extruder.

8. The method for producing ABS resin according to claim 1, characterized in that, The threaded element includes a feed thread and a shearing thread; The conveying thread is provided in the feeding conveying area, the rear section of the venting section, and the pressure building section; The shearing thread is located in the plasticizing and mixing zone and the front section of the exhaust section. The shearing thread is used to shear and mix the materials.

9. The method for producing ABS resin according to claim 1, characterized in that, The materials include, but are not limited to, ABS rubber powder, melt SAN, production aids, recycled ABS particles, or recycled SAN.

10. The method for producing ABS resin according to claim 9, characterized in that, The moisture content of the ABS rubber powder does not exceed 20 wt%.

11. The method for producing ABS resin according to claim 9, characterized in that, The amount of recycled ABS particles and recycled SAN remixed shall not exceed 20%.

12. The method for producing ABS resin according to claim 1, characterized in that, The vacuum system pressure is 0 kPaA - 100 kPaA.

13. The method for producing ABS resin according to claim 4, characterized in that, The devolatilization aid material includes, but is not limited to, devolatilization aid water. The amount of the devolatilization aid water is 0.4 wt% to 0.6 wt% of the ABS resin production and the water temperature does not exceed 60°C.

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