A two-stage extruder

Abstract

The utility model discloses a double-stage extruder, belonging to the technical field of extruders. It includes a first-stage barrel and a second-stage barrel arranged in parallel, the input end of the second-stage barrel is connected to the output end of the first-stage barrel; a first-stage screw group arranged in the first-stage barrel and a second-stage screw group arranged in the second-stage barrel, the first-stage screw group and the second-stage screw group are respectively mutually meshed co-rotating twin screws, the first-stage screw group is controlled by a first driving device, and the second-stage screw group is controlled by a second driving device; the first-stage barrel is provided with a material conveying section, a melting section, a natural exhaust section, and a mixing section in sequence; the second-stage barrel is provided with a glass fiber mixing section, a vacuum exhaust section, and a compaction conveying section in sequence. The utility model solves the problem that the existing twin-screw extruder cannot be used for the production of toughened or glass-fiber-filled modified nylon 12 at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of extruders, in particular to a double-stage extruder for producing toughened modified nylon 12 and glass fiber filled modified nylon 12. Background Art

[0002] Compared with aliphatic nylon, nylon 12 has a series of excellent properties such as low water absorption, low processing temperature, good heat and cold resistance, and high mechanical properties. It is widely used in the fields of automobiles, pipelines, and electronic appliances. In order to meet different application fields and application scenarios, nylon 12 needs to be modified. Among them, toughening modification and glass fiber filling modification are one of the commonly used modification methods. The toughness and impact performance of nylon 12 can be improved by adding toughening agents, and the rigidity and tensile properties of nylon 12 can be improved by adding glass fibers, which broadens the application range of nylon 12.

[0003] The intermeshing co-rotating twin-screw extruder is one of the most important equipment for plastic extrusion blending and modification. It uses external power transmission and heat transfer of external heating elements to carry out solid conveying, compaction, melting, shearing, mixing and extrusion molding of plastics. The intermeshing co-rotating twin-screw extruder is equipped with two parallel and mutually meshing screws, and the screws include a series of threaded elements arranged in a certain order. The screw combination, that is, the arrangement of the threaded elements, is the key to the twin-screw blending and modification. For toughened modified nylon 12, in order to make the toughening agent evenly distributed in the nylon 12 matrix according to a certain size and obtain the best performance, a strong screw shear strength is required; and for glass fiber filled modified nylon 12, in order to make the glass fiber evenly distributed in the nylon 12 matrix while retaining the length of the glass fiber to the greatest extent and obtain the best performance, a weaker screw shear strength and a stronger glass fiber distribution ability are required. Therefore, for the same extruder, in order to produce toughened or glass fiber filled modified nylon 12 and achieve optimal product performance, it is often necessary to adjust the screw combination, change the screw shear strength and reinstall it, which results in low production efficiency and high labor intensity. Utility Model Content

[0004] The technical problem to be solved by the utility model is that the existing twin-screw extruder cannot be used for producing toughened or glass fiber filled modified nylon 12 at the same time.

[0005] In view of the above technical problems, the utility model provides the following technical solutions:

[0006] A two-stage extruder comprises: a first-stage barrel and a second-stage barrel arranged in parallel, the input end of the second-stage barrel is connected to the output end of the first-stage barrel; a first-stage screw group arranged in the first-stage barrel and a second-stage screw group arranged in the second-stage barrel, the first-stage screw group and the second-stage screw group are respectively mutually meshing co-rotating twin screws, the first-stage screw group is controlled by a first driving device, and the second-stage screw group is controlled by a second driving device; a material conveying section, a melting section, a natural exhaust section, and a mixing section are sequentially arranged in the first-stage barrel; a glass fiber mixing section, a vacuum exhaust section, and a compaction conveying section are sequentially arranged in the second-stage barrel.

[0007] In some embodiments of the utility model, the material conveying section includes a conveying element, the melting section includes a shearing element, the natural exhaust section includes a conveying element, the mixing section includes a shearing element, the glass fiber mixing section includes a shearing element and a toothed disk element, the vacuum exhaust section includes a conveying element, and the compaction conveying section includes a conveying element.

[0008] In some embodiments of the present invention, the gap between the first-stage barrel and the first-stage screw assembly is smaller than the gap between the second-stage barrel and the second-stage screw assembly.

[0009] In some embodiments of the present invention, the rotation speed of the first-stage screw group is greater than that of the second-stage screw group.

[0010] In some embodiments of the utility model, the first-stage barrel is provided with a feed discharge port in the material conveying section, the first-stage barrel is provided with a natural exhaust port in the natural exhaust section, the second-stage barrel is provided with a glass fiber adding port in the glass fiber mixing section, and the second-stage barrel is provided with a vacuum exhaust port in the vacuum exhaust section.

[0011] In some embodiments of the present invention, two mutually meshing co-directional screws in the first-stage screw assembly and the second-stage screw assembly are installed at a staggered angle of 90°.

[0012] In some implementation modes of the present invention, the conveying element, the shearing element and the toothed disc element are respectively fixedly connected to the core shaft.

[0013] In some implementations of the utility model, the shearing element comprises at least two shearing blocks, the shearing blocks are respectively fixedly connected to the same core shaft, and the end faces of adjacent shearing blocks are connected and staggered with each other.

[0014] In some implementation modes of the present invention, the toothed disc element comprises a sleeve body sleeved on a core shaft, and the sleeve body is provided with at least two meshing teeth.

[0015] The technical solution of the utility model has the following technical effects compared with the prior art:

[0016] The double-stage extruder provided by the utility model is divided into a first-stage barrel and a second-stage barrel which are parallel and connected to each other. The first-stage screw group in the first-stage barrel is controlled by a first driving device, and the second-stage screw group in the second-stage barrel is controlled by a second driving device. The two processes of plasticization and mixing of the nylon 12 matrix and mixing of the glass fiber can be distinguished. The rotation speed and barrel screw gap of the two extruders can be adjusted independently, so that toughened modified nylon 12 and glass fiber filled modified nylon 12 can be produced on the same extruder without adjusting the screw combination, thereby improving production efficiency and reducing labor intensity. At the same time, the toughened and glass fiber filled modified nylon 12 prepared by the double-stage extruder can obtain the best performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, which will help to understand the purpose and advantages of the present invention, wherein:

[0018] Figure 1 A schematic structural diagram of a specific implementation of the double-stage extruder provided by the utility model;

[0019] Figure 2 A schematic structural diagram of a specific implementation of a conveying element in a two-stage extruder provided by the utility model;

[0020] Figure 3 A schematic structural diagram of a specific implementation of a shearing element in a double-stage extruder provided by the utility model;

[0021] Figure 4 The present invention is a schematic structural diagram of a specific implementation of a toothed disc element in a two-stage extruder provided by the present invention. DETAILED DESCRIPTION

[0022] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] like Figure 1 The figure shows a specific embodiment of the double-stage extruder provided by the utility model, which comprises a first-stage barrel 1 and a second-stage barrel 2 arranged in parallel, the input end of the second-stage barrel 2 is connected to the output end of the first-stage barrel 1 through a transition barrel; a first-stage screw group 3 arranged in the first-stage barrel 1 and a second-stage screw group 4 arranged in the second-stage barrel 2, the first-stage screw group 3 and the second-stage screw group 4 are respectively mutually meshing co-rotating twin screws, the first-stage screw group 3 is controlled by a first driving device 16, and the second-stage screw group 4 is controlled by a second driving device 17; the first-stage barrel 1 is provided with a material conveying section 5, a melting section 6, a natural exhaust section 7, and a mixing section 8 in sequence; the second-stage barrel 2 is provided with a glass fiber mixing section 9, a vacuum exhaust section 10, and a compaction conveying section 11 in sequence. The toughened modified nylon 12 and the glass fiber filled modified nylon 12 can be produced on the same extruder without adjusting the screw combination, thereby improving production efficiency, reducing labor intensity, and obtaining good product performance. The two-stage extruder can separate the two processes of plasticizing and mixing the nylon 12 matrix and mixing with the glass fiber. The rotation speed and barrel screw gap of the two extruders can be adjusted independently. The prepared toughened and glass fiber filled modified nylon 12 can obtain the best performance.

[0027] Specifically, in an optional embodiment, the material conveying section 5 includes a conveying element A, the melting section 6 includes a shearing element B, the natural exhaust section 7 includes a conveying element A, the mixing section 8 includes a shearing element B, the glass fiber mixing section 9 includes a shearing element B and a toothed disc element C, the vacuum exhaust section 10 includes a conveying element A, and the compacting conveying section 11 includes a conveying element A. The shearing element B with strong mixing ability is selected in the melting section 6 and the mixing section 8 of the first-stage barrel 1, and the toughening agent is evenly distributed in the nylon 12 matrix according to a certain size through distribution and dispersion mixing. The shearing element B and the toothed disc element C are used together in the glass fiber mixing section 9 of the second-stage barrel 2. After the glass fiber is fed from the glass fiber addition port 14, the glass fiber bundle is opened under the action of the shearing element B, and the glass fiber and other materials are fully mixed and uniformly under the strong distribution mixing of the toothed disc element C, while the length of the glass fiber is retained to the maximum extent.

[0028] Specifically, in an optional embodiment, the gap between the first-stage barrel 1 and the first-stage screw group 3 is smaller than the gap between the second-stage barrel 2 and the second-stage screw group 4. The rotation speed of the first-stage screw group 3 is greater than that of the second-stage screw group 4. While ensuring that the nylon 12 matrix in the first-stage barrel 1 is completely plasticized, the shear strength of the second-stage barrel 2 is reduced, and the length of the glass fiber is increased, so that the prepared toughened modified nylon 12 and glass fiber filled modified nylon 12 can both obtain optimal performance.

[0029] Specifically, in an optional embodiment, the first-stage barrel 1 is provided with a discharge port 12 in the material conveying section 5, through which material is added to the extruder and the fed air is discharged, wherein the discharge port 12 is preferably located near the feed end of the material conveying section 5; the first-stage barrel 1 is provided with a natural exhaust port 13 in the natural exhaust section 7, through which water, residual monomers, solvents and other volatiles in the extruder are removed, wherein the natural exhaust port 13 is located in the natural exhaust section 7 near the melting section 6; the second-stage barrel 2 is provided with a glass fiber addition port 14 in the glass fiber mixing section 9, and the glass fiber addition port 14 is located in the glass fiber mixing section 9 near the mixing section 8; the second-stage barrel 2 is provided with a vacuum exhaust port 15 in the vacuum exhaust section 10, through which water, residual monomers, solvents and other volatiles in the extruder are removed, and the vacuum exhaust port 15 is located in the vacuum exhaust section 10 near the glass fiber mixing section 9.

[0030] The first stage barrel 1 and the second stage barrel 2 can be an integral body, with a feed opening 12, a natural exhaust port 13, a glass fiber feeding port 14, and a vacuum exhaust port 15 provided at different locations. Figure 1The building block structure shown is, for example, divided into 7 sections and 5 sections of barrels, the first-stage barrel 1 is divided into B1, B2, B3, B4, B5, B6, B7 in sequence, and the second-stage barrel 2 is divided into B8, B9, B10, B11, B12 in sequence. In some preferred embodiments of the utility model, the feed port 12 is located at the B1 section, the natural exhaust port 13 is located at the B5 section, the glass fiber addition port 14 is located at the B8 section, and the vacuum exhaust port 15 is located at the B11 section.

[0031] Specifically, in an optional implementation manner, Figure 1 As shown, in the first-stage screw assembly 3 and the second-stage screw assembly 4, two mutually meshing co-rotating screws are installed at a staggered angle of 90°.

[0032] Specifically, in an optional embodiment, the conveying element A, the shearing element B and the toothed disc element C are respectively fixedly connected to the core shaft. Specifically, the conveying element A, the shearing element B and the toothed disc element C are respectively sleeved on the core shaft and connected to the core shaft through a spline engagement therebetween.

[0033] Specifically, in an optional embodiment, the shear element B includes at least two shear blocks, and the shear blocks are respectively fixedly connected to the same core shaft, and the end faces of adjacent shear blocks are connected and staggered.

[0034] Specifically, in an optional embodiment, the toothed disc element C includes a sleeve body sleeved on the core shaft, and the sleeve body is provided with at least two meshing teeth.

[0035] The technical effect of the double-stage extruder of the utility model is further explained below through more specific examples. The raw material information used in the following examples is as follows:

[0036] Nylon 12 resin: Wanamid L3000, produced by Wanhua Chemical Group Co., Ltd.

[0037] Antioxidant: 1010, produced by Tianjin Lianlong New Materials Co., Ltd.

[0038] Toughening agent: TSIN4013, produced by BYK Chemical, Germany.

[0039] Glass fiber: T438R, produced by Taishan Glass Fiber Co., Ltd.

[0040] The tensile strength in the embodiment is tested according to standard ISO 527, with a bar size of 170 mm×10 mm×4 mm and a tensile rate of 50 mm / min; the impact strength is tested according to standard ISO 180, cantilever beam, bar size of 80 mm×10 mm×4 mm, and A-notch.

[0041] The structure of the two-stage extruder is as follows: Figure 1 As shown, specifically, in an optional embodiment, the threaded elements on the first screw group and the second screw group are arranged in sequence as follows:

[0042] Material conveying section 5: 32 / 32A, 48 / 48, 48 / 48, 48 / 48, 48 / 48, 32 / 32, 32 / 32, 32 / 32;

[0043] Melting section 6: KB45 / 5 / 48, KB45 / 5 / 32, KB45 / 5 / 32, 32 / 32, KB45 / 5 / 32, KB45 / 5 / 32, KB45 / 5 / 32, 32 / 16L;

[0044] Natural exhaust section 7: 48 / 48, 48 / 48, 48 / 48, 48 / 48, 32 / 32, 32 / 32;

[0045] Mixing section 8: KB45 / 5 / 48, KB45 / 5 / 32, 32 / 32, KB45 / 5 / 32, KB45 / 5 / 32, 48 / 48;

[0046] Glass fiber mixing section 9: 48 / 48, 48 / 48, 48 / 48, 48 / 48, 32 / 32, KB45 / 5 / 32, 48 / 48, KB45 / 5 / 24, 48 / 48, SME8 / 16, SME8 / 16, ZME8 / 16;

[0047] Vacuum exhaust section 10: 32 / 32, 32 / 32, 48 / 48, 48 / 48;

[0048] Compacting conveying section 11: 48 / 48, 32 / 32, 32 / 32, 32 / 32;

[0049] The meaning of the thread element representation method described in the utility model is as follows:

[0050] 48 / 48 means a forward conveying element A with a lead of 48 mm and a length of 48 mm;

[0051] The A in 32 / 32A indicates that the forward thread element is the starting element of the screw;

[0052] KB45 / 5 / 48 indicates a forward shear element B with 5 teeth at a staggered angle of 45° and a lead of 32mm;

[0053] 32 / 16L means reverse conveying element A with a lead of 32 mm and a length of 16 mm;

[0054] SME8 / 16 means SME type toothed disc element C with a lead of 8 mm and a length of 16 mm;

[0055] ZME8 / 16 means a ZME toothed disc element C with a lead of 8 mm and a length of 16 mm;

[0056] Specifically, in an optional embodiment, the gap between the first-stage barrel 1 and the first-stage screw is 0.2 mm, and the gap between the second-stage barrel 2 and the second-stage screw is 0.5 mm.

[0057] Example 1

[0058] Prepare the materials according to the following formula, and the content of each component is as follows:

[0059] Nylon 12 resin Wanamid L3000, 90%;

[0060] Antioxidant 1010, 0.5%;

[0061] Toughening agent TSIN4013, 9.5%;

[0062] The above-mentioned nylon 12 resin, antioxidant and toughening agent are mixed in a high mixer at a mixing temperature of 25°C and a rotation speed of 100 rpm for 5 minutes. The evenly mixed material is added through the discharge port 12 of the first-stage barrel 1 of the two-stage extruder; the screw temperature is set to 30°C, 200°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C from the feed end of the first-stage barrel 1 to the discharge end of the second-stage barrel 2, with a production capacity of 50kg / h, a first-stage screw speed of 450rpm, and a second-stage screw speed of 300rpm.

[0063] Example 2

[0064] Prepare the materials according to the following formula, and the content of each component is as follows:

[0065] Nylon 12 resin Wanamid L3000, 69.5%

[0066] Antioxidant 1010, 0.5%;

[0067] Glass fiber T438R, 30%;

[0068] The above-mentioned nylon 12 resin and antioxidant are mixed in a high mixer at a mixing temperature of 25°C and a rotation speed of 100 rpm for 5 minutes. The evenly mixed materials are added through the discharge port 12 of the first-stage barrel 1 of the two-stage extruder, and the glass fiber is added from the glass fiber adding port 14 of the second-stage barrel 2; the screw temperature is set to 30°C, 200°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C from the feeding end of the first-stage barrel 1 to the discharging end of the second-stage barrel 2, with a production capacity of 100 kg / h, a first-stage screw speed of 400 rpm, and a second-stage screw speed of 250 rpm.

[0069] Comparative Example 1

[0070] Prepare the materials according to the following formula, and the content of each component is as follows:

[0071] Nylon 12 resin Wanamid L3000, 90%;

[0072] Antioxidant 1010, 0.5%;

[0073] Toughening agent TSIN4013, 9.5%;

[0074] The above-mentioned nylon 12 resin, antioxidant and toughening agent are mixed in a high mixer at a mixing temperature of 25°C and a rotation speed of 100 rpm for 5 minutes. The evenly mixed materials are added through the discharge port 12 of the first-stage barrel 1 of the two-stage extruder; the screw temperature is set to 30°C, 200°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C from the feed end of the first-stage barrel 1 to the discharge end of the second-stage barrel 2, with a production capacity of 50 kg / h and a first-stage and second-stage screw speed of 300 rpm.

[0075] Comparative Example 2

[0076] Prepare the materials according to the following formula, and the content of each component is as follows:

[0077] Nylon 12 resin Wanamid L3000, 69.5%

[0078] Antioxidant 1010, 0.5%;

[0079] Glass fiber T438R, 30%;

[0080] The above-mentioned nylon 12 resin and antioxidant are mixed in a high mixer at a mixing temperature of 25°C and a rotation speed of 100 rpm for 5 minutes. The evenly mixed materials are added through the discharge port 12 of the first-stage barrel 1 of the two-stage extruder, and the glass fiber is added from the glass fiber adding port 14 of the second-stage barrel 2; the screw temperature is set to 30°C, 200°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C, 230°C from the feeding end of the first-stage barrel 1 to the discharging end of the second-stage barrel 2, with a production capacity of 100 kg / h and a first-stage and second-stage screw speed of 400 rpm.

[0081] The properties of the toughened and glass fiber filled modified nylon 12 prepared in Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1.

[0082] Table 1 Performance table of modified nylon 12 in the examples and comparative examples

[0083] performance Tensile strength(MPa) Tensile modulus (MPa) <![CDATA[Izod impact strength (kJ / m 2 )]]> Example 1 52 817 105 Example 2 133 8500 36 Comparative Example 1 36 639 81 Comparative Example 2 89 6673 26

[0084] It can be seen that the tensile strength, tensile modulus, and Izod notch impact of Example 1 are better than those of Comparative Example 1, and the tensile strength, tensile modulus, and Izod notch impact of Example 2 are better than those of Comparative Example 2, indicating that for toughened modified nylon 12, increasing the speed of the first-stage screw is beneficial to the dispersion of the toughening agent, and for glass fiber-filled modified nylon 12, reducing the speed of the second-stage screw is beneficial to retaining the glass fiber length, thereby improving the mechanical properties. Using the two-stage extruder provided by the utility model, both toughened and glass fiber-filled modified nylon 12 products can obtain better performance.

[0085] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present utility model.

Claims

1. A two-stage extruder, characterized in that: include: A first-stage barrel and a second-stage barrel are arranged in parallel, and the input end of the second-stage barrel is connected to the output end of the first-stage barrel; A first-stage screw group disposed in the first-stage barrel and a second-stage screw group disposed in the second-stage barrel, wherein the first-stage screw group and the second-stage screw group are respectively mutually meshing co-rotating twin screws, the first-stage screw group is controlled by a first driving device, and the second-stage screw group is controlled by a second driving device; The first-stage barrel is provided with a material conveying section, a melting section, a natural exhaust section, and a mixing section in sequence; the second-stage barrel is provided with a glass fiber mixing section, a vacuum exhaust section, and a compacting and conveying section in sequence.

2. A two-stage extruder according to claim 1, characterized in that: The material conveying section includes a conveying element, the melting section includes a shearing element, the natural exhaust section includes a conveying element, the mixing section includes a shearing element, the glass fiber mixing section includes a shearing element and a toothed disk element, the vacuum exhaust section includes a conveying element, and the compaction conveying section includes a conveying element.

3. A two-stage extruder according to claim 1, characterized in that: The gap between the first-stage barrel and the first-stage screw group is smaller than the gap between the second-stage barrel and the second-stage screw group.

4. A two-stage extruder according to claim 1, characterized in that: The rotation speed of the first-stage screw group is greater than that of the second-stage screw group.

5. A two-stage extruder according to claim 1, characterized in that: The first-stage barrel is provided with a material discharge port in the material conveying section, the first-stage barrel is provided with a natural exhaust port in the natural exhaust section, the second-stage barrel is provided with a glass fiber adding port in the glass fiber mixing section, and the second-stage barrel is provided with a vacuum exhaust port in the vacuum exhaust section.

6. A two-stage extruder according to claim 1, characterized in that: In the first-stage screw assembly and the second-stage screw assembly, two mutually meshing co-rotating screws are installed at a staggered angle of 90°.

7. A two-stage extruder according to claim 2, characterized in that: The conveying element, the shearing element and the toothed disc element are respectively fixedly connected to the core shaft.

8. A two-stage extruder according to claim 7, characterized in that: The shearing element comprises at least two shearing blocks, which are respectively fixedly connected to the same core shaft, and the end faces of adjacent shearing blocks are connected and arranged in staggered rows.

9. A two-stage extruder according to claim 7, characterized in that: The toothed disc element comprises a sleeve body sleeved on a core shaft, and the sleeve body is provided with at least two meshing teeth.

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