A double screw combined structure suitable for modified ASA plastic

Abstract

The application discloses a double-screw combined structure suitable for modified ASA plastic, and belongs to the technical field of polymer material processing, which comprises a barrel and a combined screw, the combined screw is sequentially provided with a feeding section, a plasticizing and shearing section, a venting section and an extruding section, a feeding port corresponds to the feeding section, a venting port corresponds to the plasticizing and shearing section, and a vacuum port corresponds to the venting section; the feeding section comprises a first conveying section, the plasticizing and shearing section comprises sequentially arranged first engaging sections, a second conveying section, second engaging sections, a third conveying section, third engaging sections and a fourth conveying section, the venting section comprises sequentially arranged fifth conveying sections, a reverse section and sixth conveying sections, and the extruding section comprises a seventh conveying section; each conveying section comprises one or more conveying blocks; each engaging section comprises one or more engaging blocks; and the reverse section comprises one or more reverse blocks. The application can modify the ASA plastic by repeatedly performing the engaging and conveying processes in the plasticizing and shearing section, and better product quality can be obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer material processing, in particular to a double screw combined structure suitable for modified ASA plastic. BACKGROUND

[0002] In the process of plastic modification, the properties of the plastic raw materials involved are different, and the modified plastics have different uses and product performance requirements, so the performance requirements of the screw are different. In actual use, the screw combination and operating parameters can be adjusted according to the product use, characteristics, etc. Reasonable screw combination is the basic condition for manufacturing high-quality plastic processing products. However, in industry, more attention is often paid to the adjustment of screw operation process, and less attention is paid to the adjustment of screw structure.

[0003] Since the double screw adopts a building block type combined structure, it is very convenient to replace it during use. In the extrusion process, the screw works under high temperature, strong friction and gas corrosion conditions, and the screw elements and barrel can withstand the above environmental tests. The material has certain requirements, and the screw element adopts high-strength wear-resistant material. The configuration principle of the material of the screw element and the barrel is rigid and flexible combination.

[0004] For the modification of ASA plastic, not only the form, performance and ratio of the ASA plastic to be mixed need to be correctly analyzed, but also the screw elements and the functions of each zone of the screw, the working principle and the screw configuration need to be understood. The thermal properties and flow processing properties of different polymers are different, and the heat resistance and dispersibility of various plastic processing aids are different. On the basis of fully analyzing the component physical properties and ratio of the blending system and the product performance requirements, the combination of the screw is determined, which is very important for the quality of ASA products.

[0005] There is little introduction of ASA plastic modification in the existing patent literature for modified ASA plastic for resin tile surface co-extrusion. For example, a screw for a meshing co-rotating twin screw extruder is disclosed in Chinese Patent Publication No. CN 102700109A, which does not introduce the specific material type. Chinese Patent Publication No. CN 102320117A discloses a method for preparing glass fiber reinforced AS resin, which is only applicable to AS resin. Chinese Patent No. CN 109130138B discloses a method for combining all single-threaded screw sleeves of a parallel double screw extruder, which is specifically used for waste plastics to avoid damage to threaded elements due to waste metals and impurities. Chinese Patent No. CN 209552413U discloses a double screw extruder for ASA production, which is used for ASA production, but does not improve the screw combination.

[0006] In summary, how to reasonably combine the screw to be able to modify the ASA plastic and obtain better product quality of the ASA plastic, the prior art has no mature technology. SUMMARY

[0007] The purpose of the present application is to provide a double screw combination structure suitable for modifying ASA plastic to solve the problems existing in the prior art, by dividing the combination screw into feeding section, plasticizing and shearing section, exhaust section and extrusion section, and repeatedly engaging and conveying in the plasticizing and shearing section, the ASA plastic can be modified to obtain better product quality.

[0008] To achieve the above purpose, the present application provides the following scheme:

[0009] The present application provides a double screw combination structure suitable for modifying ASA plastic, comprising a barrel, a combination screw arranged in the barrel, and a feeding port, an exhaust port and a vacuum port arranged on the barrel, the combination screw is sequentially provided with a feeding section, a plasticizing and shearing section, an exhaust section and an extrusion section from the feeding side to the discharging side, the feeding port corresponds to the feeding section, the exhaust port corresponds to the plasticizing and shearing section, and the vacuum port corresponds to the exhaust section; the feeding section comprises a first conveying section, the plasticizing and shearing section comprises a first engaging section, a second conveying section, a second engaging section, a third conveying section, a third engaging section and a fourth conveying section arranged in sequence, the exhaust section comprises a fifth conveying section, a reverse section and a sixth conveying section arranged in sequence, and the extrusion section comprises a seventh conveying section; the first conveying section, the second conveying section, the third conveying section, the fourth conveying section, the fifth conveying section, the sixth conveying section and the seventh conveying section respectively comprise one or more conveying blocks; the first engaging section, the second engaging section and the third engaging section respectively comprise one or more engaging blocks; and the reverse section comprises one or more reverse blocks.

[0010] Preferably, the feeding port corresponds to the first conveying section, the exhaust port corresponds to the third conveying section, and the vacuum port corresponds to the reverse section and the sixth conveying section.

[0011] Preferably, the combination screw comprises a core shaft and the conveying blocks, the engaging blocks and the reverse blocks sleeved and installed on the core shaft.

[0012] Preferably, the barrel comprises a plurality of axially connected barrel sections, the length of each barrel section is equal, the feeding section comprises two barrel sections, the plasticizing and shearing section comprises six barrel sections, the exhaust section comprises one barrel section, and the extrusion section comprises one barrel section.

[0013] Preferably, the ASA plastic comprises 15%-20% by weight of ASA, 85%-80% by weight of AS, 0.2%-0.4% by weight of antioxidant, and 0.5%-1.0% by weight of ultraviolet inhibitor.

[0014] Preferably, the conveying block adopts specifications of 56 / 56, 44 / 44, 72 / 72, 64 / 64 in terms of pitch / total length; the meshing block adopts specifications of 90° / 5 / 56, 45° / 5 / 56, 45° / 5 / 36, 45° / 5 / 44, 60° / 4 / 44, 30° / 7 / 72, 60° / 4 / 56 in terms of meshing disc rotation angle / meshing disc number / total length; and the reversing block adopts specifications of 44 / 22L in terms of pitch / total length L.

[0015] Preferably, the first conveying section comprises 56 / 56, 72 / 72*4 and 64 / 64*2 arranged in sequence.

[0016] Preferably, the first meshing section comprises 45° / 5 / 96, 60° / 4 / 56, 45° / 5 / 56 and 45° / 5 / 44 arranged in sequence; the second conveying section comprises 44 / 44 and 56 / 56*4 arranged in sequence; the second meshing section comprises 60° / 4 / 56, 45° / 5 / 56, 60° / 4 / 44 and 90° / 5 / 56 arranged in sequence; the third conveying section comprises 72 / 72*3 and 56 / 56 arranged in sequence; the third meshing section comprises 45° / 5 / 56, 45° / 5 / 36 and 90° / 5 / 56 arranged in sequence; and the fourth conveying section comprises 56 / 56*5 arranged in sequence.

[0017] Preferably, the fifth conveying section comprises 44 / 44; the reversing section comprises 44 / 22L; and the sixth conveying section comprises 72 / 72*2 arranged in sequence.

[0018] Preferably, the seventh conveying section comprises 56 / 56*3 and 44 / 44*2 arranged in sequence.

[0019] The present application has the following technical effects relative to the prior art:

[0020] (1) The present application can modify ASA plastic and obtain better product quality by dividing the combined screw into a feeding section, a plasticizing shearing section, a venting section and an extruding section, and repeatedly performing meshing and conveying processes in the plasticizing shearing section.

[0021] (2) the conveying block adopts specifications of 56 / 56, 44 / 44, 72 / 72, 64 / 64, the engaging block adopts specifications of 90° / 5 / 56, 45° / 5 / 56, 45° / 5 / 36, 45° / 5 / 44, 60° / 4 / 44, 30° / 7 / 72, 60° / 4 / 56, the reverse block adopts specifications of 44 / 22L, through reasonable combination and assembly, a specific combination mode is formed, the best combination mode is selected through experiments in the multiple combination modes, the combination mode not only greatly improves the compatibility of ASA mixed materials and the dispersibility of toner, but also is excellent in use, and has good prospects and economic benefits in the fields of automobiles, home decoration, outdoor sports and the like. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0023] Fig. 1 It is a schematic diagram of the structure of the present application;

[0024] Fig. 2 It is a schematic diagram of the structure of the present application;

[0025] Fig. 3 It is a schematic diagram of the structure of the present application;

[0026] Among them, 1, mandrel; 2, barrel section; 3, feeding port; 4, exhaust port; 5, vacuum port; 6, conveying block; 7, engaging block; 8, reverse block; 10, feeding section; 20, plasticizing and shearing section; 30, exhaust section; 40, extrusion section. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] The purpose of the present application is to provide a double-screw combination structure suitable for modified ASA plastic, to solve the problems in the prior art, by dividing the combination screw into a feeding section, a plasticizing and shearing section, an exhaust section and an extrusion section, and repeatedly engaging and conveying in the plasticizing and shearing section, the ASA plastic can be modified to obtain better product quality.

[0029] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0030] As shown in Figs. 1-3 The present application provides a double screw combined structure suitable for modified ASA plastic, which comprises a barrel, a combined screw arranged in the barrel, and a feeding port 3, an exhaust port 4 and a vacuum port 5 arranged on the barrel. The barrel can adopt an integral structure extending in the axial direction, or can be provided with multiple barrel segments 2 arranged in sections. The combined screw rotates in the barrel to transport, plasticize and shear the ASA plastic, so that the ASA plastic is discharged after being modified in the barrel. The combined screw adopts a building block type double screw combined structure. The combined screw is sequentially provided with a feeding segment 10, a plasticizing and shearing segment 20, an exhaust segment 30 and an extruding segment 40 from the feeding side to the discharging side. The feeding port 3 corresponds to the feeding segment 10, and the ASA plastic to be processed enters the barrel through the feeding port 3. The exhaust port 4 corresponds to the plasticizing and shearing segment, and the water vapor and the like generated in the process of plasticizing and shearing the ASA plastic is naturally discharged through the exhaust port 4. The vacuum port 5 corresponds to the exhaust segment 30, and the vacuum port 5 is connected with a vacuum device to further extract the gas in the barrel by negative pressure. The feeding segment 10 comprises a first conveying segment, the plasticizing and shearing segment 20 comprises sequentially arranged first meshing segments, second conveying segments, second meshing segments, third conveying segments, third meshing segments and fourth conveying segments, the exhaust segment 30 comprises sequentially arranged fifth conveying segments, reverse segments and sixth conveying segments, and the extruding segment 40 comprises a seventh conveying segment. The first conveying segment, the second conveying segment, the third conveying segment, the fourth conveying segment, the fifth conveying segment, the sixth conveying segment and the seventh conveying segment each comprise one or more conveying blocks 6, and the conveying blocks 6 are used for conveying materials and establishing pressure by changing the screw groove and the screw pitch. The first meshing segment, the second meshing segment and the third meshing segment each comprise one or more meshing blocks 7, and the meshing blocks 7 are used for shearing and melting the ASA plastic. The reverse segment comprises one or more reverse blocks 8, and the reverse blocks 8 are opposite to the conveying direction of the conveying blocks 6, and are used for prolonging the residence time of the ASA plastic in the barrel and preventing the vacuum port 5 from spouting. The conveying blocks 6, the meshing blocks 7 and the reverse blocks 8 are matched and arranged according to the length of the combined screw and the barrel. The present application can modify the ASA plastic by repeatedly performing the meshing and conveying process in the plasticizing and shearing segment 20, so as to obtain better product quality.

[0031] Further, the feeding port 3 can correspond to the first conveying segment, the exhaust port 4 can correspond to the third conveying segment, and the vacuum port 5 can correspond to the reverse segment and the sixth conveying segment. The material fed through the feeding port 3 can be continuously conveyed along the barrel through the first conveying segment, so as to avoid accumulation at the feeding port 3. Natural exhaust or vacuum exhaust is performed in the path segment of the extruding and conveying, so as to keep the ASA plastic moving in the barrel and prevent the ASA plastic from spouting from the exhaust port 4 and the vacuum port 5.

[0032] The combined screw comprises a core shaft 1, a conveying block 6, an engaging block 7 and a reverse block 8 which are sleeved and installed on the core shaft 1. The conveying block 6, the engaging block 7 and the reverse block 8 rotate synchronously with the rotation of the core shaft 1.

[0033] The barrel can comprise several axially connected barrel segments 2, each barrel segment 2 has equal length, and different barrel segments 2 are connected by flanges. For example, each barrel segment 2 has a length of 240 mm, and ten barrel segments 2 are used in total, with a total length of 2400 mm, and the total length of the combined screw is 2370 mm. The feeding section 10 comprises two barrel segments 2, one of which is provided with a feeding port 3. The plasticizing shearing section 20 comprises six barrel segments 2, one of which is provided with an exhaust port 4. The exhaust section 30 comprises one barrel segment 2, which is provided with a vacuum port 5. The extrusion section 40 comprises one barrel segment 2.

[0034] The ASA plastic comprises 15%-20% by weight of ASA, 85%-80% by weight of AS, 0.2%-0.4% by weight of antioxidant, and 0.5%-1.0% by weight of ultraviolet resistant agent.

[0035] Further, the conveying block 6, the engaging block 7 and the reverse block 8 can be selected from the following specifications. Specifically, the conveying block 6 adopts specifications, i.e. pitch / total length is 56 / 56, 44 / 44, 72 / 72, 64 / 64. For example, 44 / 44 means that the conveying block 6 has a pitch of 44 mm and a total length of 44 mm. The engaging block 7 adopts specifications, i.e. engaging disc rotation angle / number of engaging discs / total length is 90° / 5 / 56, 45° / 5 / 56, 45° / 5 / 36, 45° / 5 / 44, 60° / 4 / 44, 30° / 7 / 72, 60° / 4 / 56. For example, 45° / 5 / 36 means that the engaging block 7 has an engaging disc rotation angle of 45°, five engaging discs, and a total length of 36 mm. The reverse block 8 adopts specifications, i.e. pitch / total length L is 44 / 22L, which means that the reverse block 8 has a pitch of 44 mm and a total length of 22 mm, and L represents left. According to the structure shown in the figure, the conveying direction of the conveying block 6 is right, and the spiral direction of the reverse block 8 is opposite to that of the conveying block 6. Figs. 1-3

[0036] As shown in the figure, among the above-provided specifications of the conveying block 6, the engaging block 7 and the reverse block 8, the first conveying section is provided to comprise 56 / 56, 72 / 72*4 and 64 / 64*2 which are sequentially arranged. Fig. 2

[0037] As shown in the figure, among the above-provided specifications of the conveying block 6, the engaging block 7 and the reverse block 8, the first conveying section is provided to comprise 56 / 56, 72 / 72*4 and 64 / 64*2 which are sequentially arranged. Fig. 2 ​​As shown in the figure, the first meshing section includes 45° / 5 / 96, 60° / 4 / 56, 45° / 5 / 56 and 45° / 5 / 44 arranged in sequence. The second conveying section includes 44 / 44, 56 / 56*4 arranged in sequence. The second meshing section includes 60° / 4 / 56, 45° / 5 / 56, 60° / 4 / 44 and 90° / 5 / 56 arranged in sequence. The third conveying section includes 72 / 72*3 and 56 / 56 arranged in sequence. The third meshing section includes 45° / 5 / 56, 45° / 5 / 36 and 90° / 5 / 56 arranged in sequence. The fourth conveying section includes 56 / 56*5 arranged in sequence.

[0038] As shown in the figure, the fifth conveying section includes 44 / 44. The reverse section includes 44 / 22L. The sixth conveying section includes 72 / 72*2 arranged in sequence. Fig. 2

[0039] As shown in the figure, the seventh conveying section includes 56 / 56*3 and 44 / 44*2 arranged in sequence. Fig. 2

[0040] Through reasonable combination and assembly, the combined screw can form a specific combination mode. Among a plurality of combination modes, the best combination mode is selected through experiments. The combination mode not only greatly improves the compatibility of ASA mixed materials and the dispersibility of toner, but also has excellent use process, and has good prospects and economic benefits in the fields of automobiles, home decoration, outdoor sports and the like.

[0041] The three combined screw structures shown in the figure can realize modification treatment of ASA plastic, and can improve the quality of the obtained product compared with the prior art. On this basis, the optimal combined screw structure can be selected from the three combined screw structures, and the effectiveness thereof is verified through experiments, as follows: Figs. 1-3

[0042] The method includes the following steps:

[0043] (1) In the case of unchanged ASA plastic, three modes of structure combination of the combined screw are performed, and extrusion granulation is performed. The rationality of the screw structure is evaluated through physical properties of the extruded product;

[0044] (2) The combined screw is combined in three different structures, installed and extruded and granulated;

[0045] (3) The rationality of the screw structure is evaluated through physical property detection of the extruded product.

[0046] Table 1: Three screw structures

[0047]

[0048] ​​​Through the above three different combination structure, using the same material ratio of ASA plastic extrusion granulation; again on the granule drying injection molding into the national standard sample, and test sample physical data, to analyze the advantages and disadvantages of three different structure screw combination.

[0049] Table 2: three different screw structure in the process of extrusion draw granulation and and resin tile co-extrusion process

[0050]

[0051] Table 3: three different screw structure granulation injection detection physical

[0052]

[0053] Note: the project for the focus of the test project

[0054] Table 4: three different screw structure of granulation particles extrusion film detection process

[0055]

[0056] The experimental results of different screw structure

[0057] From table 2, three screw structure extrusion strip, can be seen: only structure two screw combination plastic strip is very stable, smooth, no outside strip fold bad phenomenon, meet the requirements; structure one and structure three combination does not meet the requirements.

[0058] From table 3, three screw structure of extruded particles injection detection, can be seen: structure two granulation detection results meet the requirements, structure two basically meet the requirements, structure three completely does not meet the requirements. It is proved that the structure two screw combination method plays a very good role in the dispersion of modified ASA.

[0059] From table 4, three screw structure of extruded granulation film, can be seen: structure three screw combination method of modified ASA is very poor, resulting in the process of film ASA particles have not been fully dispersed, film has white spots on the ASA is not completely dispersed small particles. Structure one appearance is slightly worse, structure two appearance is very good, which shows that the structure two screw combination method plays a very good effect on the shear dispersion of ASA modification.

[0060] From the above three detection results, it can be seen that the structure two screw combination method is the best, which can best meet the modified ASA, and has very good effect on the dispersion of ASA in the modified material.

[0061] The application modifies ASA by changing different thread blocks (conveying block 6, meshing block 7 and reverse block 8) of a double screw combination, realizes the dispersion degree of ASA in mixed materials by different thread block combination modes, and then determines the rationality of the screw combination structure by different detection modes. It can be seen from the above experimental results that the physical properties and appearance film forming of structure two have no problems, which shows that the screw combination mode of structure two of the application is effective for improving the physical properties of modified ASA, and the application has practical significance.

[0062] The principles and implementation manners of the application are described by using specific examples in the application, and the above examples are only used to help understand the method and core idea of the application; meanwhile, for the general skilled in the art, the specific implementation manners and application ranges will be changed according to the idea of the application. In conclusion, the content of the specification should not be understood as the limitation of the application.

Claims

1. A twin-screw assembly structure suitable for modifying ASA plastics, characterized by: The invention comprises a barrel, a combination screw arranged in the barrel, and a feeding port, an exhaust port and a vacuum port arranged on the barrel, wherein the combination screw is provided with a feeding section, a plasticizing and shearing section, an exhaust section and an extrusion section in sequence from the feeding side to the discharging side, the feeding port corresponds to the feeding section, the exhaust port corresponds to the plasticizing and shearing section, and the vacuum port corresponds to the exhaust section; the feeding section comprises a first conveying section, the plasticizing and shearing section comprises a first meshing section, a second conveying section, a second meshing section, a third conveying section, a third meshing section and a fourth conveying section in sequence, the exhaust section comprises a fifth conveying section, a reverse section and a sixth conveying section in sequence, and the extrusion section comprises a seventh conveying section; the first conveying section, the second conveying section, the third conveying section, the fourth conveying section, the fifth conveying section, the sixth conveying section and the seventh conveying section respectively comprise one or more conveying blocks; the first meshing section, the second meshing section and the third meshing section respectively comprise one or more meshing blocks; the reverse section comprises one or more reverse blocks; The feeding port corresponds to the first conveying section, the exhaust port corresponds to the third conveying section, and the vacuum port corresponds to the reverse section and the sixth conveying section; ASA plastic includes 15%-20% by weight of ASA, 85%-80% by weight of AS, 0.2%-0.4% by weight of antioxidant, and 0.5%-1.0% by weight of anti-ultraviolet agent; The conveying block adopts the specifications of pitch / total length of 56 / 56, 44 / 44, 72 / 72, and 64 / 64; the meshing block adopts the specifications of meshing disc angle / number of meshing discs / total length of 90° / 5 / 56, 45° / 5 / 56, 45° / 5 / 36, 45° / 5 / 44, 60° / 4 / 44, 30° / 7 / 72, and 60° / 4 / 56; the reverse block adopts the specifications of pitch / total length L of 44 / 22L; The first conveying section includes 56 / 56, 72 / 72*4 and 64 / 64*2 arranged in sequence; The first meshing section includes 45° / 5 / 96, 60° / 4 / 56, 45° / 5 / 56 and 45° / 5 / 44 arranged in sequence; the second conveying section includes 44 / 44, 56 / 56*4 arranged in sequence; the second meshing section includes 60° / 4 / 56, 45° / 5 / 56, 60° / 4 / 44 and 90° / 5 / 56 arranged in sequence; the third conveying section includes 72 / 72*3 and 56 / 56 arranged in sequence; the third meshing section includes 45° / 5 / 56, 45° / 5 / 36 and 90° / 5 / 56 arranged in sequence; the fourth conveying section includes 56 / 56*5 arranged in sequence; The fifth conveying section includes 44 / 44; the reverse section includes 44 / 22L; the sixth conveying section includes 72 / 72*2 arranged in sequence; The seventh conveying section includes 56 / 56*3 and 44 / 44*2 arranged in sequence.

2. The twin-screw assembly structure suitable for modifying ASA plastics according to claim 1, characterized in that: The combined screw comprises a core shaft and the conveying block, the engaging block and the reversing block sleeved on the core shaft.

3. The twin-screw assembly structure suitable for modifying ASA plastics according to claim 2, characterized in that: The cylinder includes several axially connected cylinder segments, each of which has the same length. The feeding segment includes two cylinder segments, the plasticizing and shearing segment includes six cylinder segments, the exhaust segment includes one cylinder segment, and the extrusion segment includes one cylinder segment.

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