Thermoplastic polyester foam forming device

Abstract

The utility model relates to the technical field of polyester foaming, in particular to a thermoplastic polyester foaming forming device. Thermoplastic polyester is easy to hydrolyze at high temperature, moisture in polyester chips needs to be removed by adopting a pre-drying technology before screw extrusion, and the pre-drying technology is long in time consumption, low in efficiency and high in energy consumption. In order to solve the problems, the utility model provides a thermoplastic polyester foam forming device which comprises a multi-screw extruder, a melt pump, a static mixer, a foaming machine head and a forming and shaping device which are connected in sequence, compared with the mode that only a double-screw extruder is adopted as the screw extrusion device, the arrangement of the planetary screw section in the multi-screw extruder has the advantages that the shearing and mixing effects in the radial direction and the transverse direction of the screws are better, materials are blended more uniformly in the radial direction and the axial direction, the mixing area is larger, and meanwhile, when vacuumizing is carried out, the working efficiency is greatly improved. And more moisture in the material escapes from the vacuum exhaust port at a higher speed in a short time, so that the removal efficiency of the moisture in the material is higher, and the removal effect is better.

Description

Technical Field

[0001] The utility model relates to the technical field of polyester foaming, in particular to a thermoplastic polyester foaming molding device. Background Art

[0002] Thermoplastic polyester foam has the advantages of good dimensional stability at high temperature, excellent mechanical properties and fatigue resistance, low smoke, flame retardancy, non-toxicity, low water absorption, good gas barrier properties and recyclability, and has broad application prospects in wind power generation, rail transportation, automotive industry and other fields. However, thermoplastic polyester has low melt viscosity, poor thermal stability, easy to absorb moisture and thermal degradation and hydrolysis, especially hydrolysis, which will cause a sharp drop in polyester molecular weight;

[0003] In order to overcome the disadvantage of thermoplastic polyester being easily hydrolyzed at high temperature, pre-drying technology is usually used to remove moisture from polyester chips. Pre-drying is commonly used in three forms: vacuum drum drying, rotary filling combined drying and fluidized bed. Continuous airflow drying is commonly used. The drying process is 140℃, 3-4h, and after drying, it must be kept warm at 100-110℃ or placed in a dry and sealed container for standby use. The feeding hopper must also be irradiated with infrared rays to maintain a dry state, or a N2-protected feeding device must be used. This pre-drying process has complex equipment, a long drying process, low efficiency and high energy consumption.

[0004] Chinese utility model patent CN203031914U discloses a PET twin-screw sheet extrusion device that does not require crystallization and drying, including a feeding device, a screw extruder and a sheet extrusion device, wherein the screw extruder is a co-directional parallel twin-screw extruder, on which a plurality of vacuum pumping devices are configured. In order to improve the dehydration efficiency, the vacuum absolute pressure provided by the vacuum pumping device of the patented technical solution is ≤0.5mbar, and the degassing capacity is greater than 1000l / s. This technical solution lacks adaptability for the need to add a variety of low-molecular additive components during the polyester reaction extrusion foaming process. Excessive vacuum and degassing will cause low-molecular additives (chain extenders, plasticizers, etc.) to be vacuum-extracted, thereby reducing the efficiency of the chain extension reaction, and the viscoelasticity of the polyester melt cannot meet the foaming requirements, and the integrated production of PET drying-free reaction extrusion foaming cannot be achieved.

[0005] US utility model patent US5958164 discloses a thermoplastic polyester foaming method, comprising: directly adding polyester and additives into a first-stage twin-screw extruder, removing moisture adsorbed by the polyester through a vacuum exhaust section on the twin-screw extruder, and then injecting a foaming agent, foaming in a downstream low-pressure zone to obtain a PET foamed product, in particular, adding fluoroplastics to the polyester, and the vacuum degassing pressure is lower than 20 Torr (2666 Pa). In this technical solution, the foaming agent (such as butane) is injected from a second-stage single-screw extruder, and the diameter of the single screw is equal to the diameter of the twin screw. In order to fully mix the foaming agent with the PET melt, the single screw has a high speed, and high shear heat is easily generated during processing. The temperature of the PET melt cannot be accurately controlled, resulting in an unstable extrusion process and low head pressure, and it is difficult to obtain a foaming density lower than 200 kg / m 3 And the thickness of PET foam board is greater than 30mm.

[0006] Chinese utility model patent CN 109435194 discloses a device for thermoplastic polyester foaming, comprising a twin-screw extruder, a melt pump, a single-screw extruder, a static mixer, a foaming die head and a forming and shaping device. The length-to-diameter ratio of the twin screws of the twin-screw extruder is between 35 and 45, and a natural exhaust port and at least one vacuum exhaust port are provided on the barrel of the twin-screw extruder. However, due to the limited blending shear force that the twin-screw extruder can provide, the radial or lateral blending effect of the thermoplastic material is not good in a short time. In a short time, the moisture in the thermoplastic material cannot be quickly and completely removed, and the drying level of the thermoplastic material does not meet the requirements, so it is difficult to obtain a foamed polyester material with performance that meets the standards. Utility Model Content

[0007] The existing problems in the prior art are: thermoplastic polyester is easily hydrolyzed at high temperature, and pre-drying technology is required to remove moisture from polyester chips before screw extrusion. The pre-drying process is time-consuming, inefficient and energy-intensive. Based on the above problems, the utility model provides a thermoplastic polyester foaming molding device, which includes a multi-screw extruder, a melt pump, a static mixer, a foaming head and a molding and shaping device connected in sequence.

[0008] The multi-screw extruder comprises a screw transmission device, a first single screw segment, a planetary screw segment and a second single screw segment which are connected in sequence.

[0009] The first extrusion screw, the central screw, and the second extrusion screw in the first single screw segment, the planetary screw segment, and the second single screw segment are coaxially fixedly connected in sequence to form a combined screw.

[0010] The combined screw is coaxial with the extruder barrel and is arranged in parallel in the extruder barrel. The combined screw is fixedly connected to the screw transmission device and rotates circumferentially under the rotation torque provided by the screw transmission device.

[0011] The thermoplastic material is heated in the combined screw and transported to the melt pump, static mixer, foaming head and molding device in sequence.

[0012] The thermoplastic material is fed in turn through the feeding port opened at the end of the first single screw section, exhausted through the vacuum exhaust port opened on the outer wall of the planetary screw section barrel, and volatile functional additives (such as chain extenders, plasticizers, etc.) are added through the side feeding port, and liquid foaming agents such as carbon dioxide, nitrogen, and alkanes are injected through the liquid injection port opened on the outer wall of the second single screw section barrel.

[0013] The planetary screw segment accounts for 20%-60% of the total length of the combined screw, and the first single screw segment accounts for 20%-40% of the total length of the combined screw;

[0014] The outer wall of the planetary screw segment barrel is provided with a side feeding port, which is used to add functional additives (such as small molecule chain extenders, plasticizers, etc.). The horizontal distance between the vacuum exhaust port and the side feeding port along the axis of the extruder barrel accounts for 30-80% of the total length of the planetary screw segment.

[0015] Compared with twin-screw extrusion, planetary screw extrusion has better blending and conveying capabilities. Thermoplastic materials are subjected to greater blending shear force in the planetary screw. In a short period of time, the water vaporizes and is discharged from the thermoplastic material faster and more fully.

[0016] The vacuum exhaust port is arranged in the planetary screw section, so that low molecular weight substances and moisture in the thermoplastic material can be vacuum removed.

[0017] There is a certain distance between the feeding port on the side of the planetary screw segment and the vacuum exhaust port, which can achieve the removal of moisture before adding reactive low-molecular additives. On the one hand, it ensures that the moisture in the thermoplastic material is fully removed, and at the same time avoids the low-molecular additives from being extracted at the vacuum exhaust port, affecting the reaction metering and the deterioration of the properties of the obtained foaming molding material.

[0018] Preferably, the vacuum exhaust port is located above the outer wall of the planetary screw section barrel, and the axis of the vacuum exhaust port is perpendicular to the axis of the extruder barrel.

[0019] Preferably, the side feed port is located at the lower side of the outer wall of the planetary screw section barrel, and the axis of the side feed port is perpendicular to the axis of the extruder barrel.

[0020] Preferably, the first single screw segment includes a first screw barrel and a first extrusion screw in the first screw barrel, the first extrusion screw is coaxial with the first screw barrel and is arranged in parallel in the first screw barrel, the first screw barrel is provided with a feeding port near the screw transmission device, the feeding port is connected to the first screw barrel, one end of the first extrusion screw is fixedly connected to the screw transmission device, and the other end is fixedly connected to the central screw of the planetary screw segment, and the aspect ratio of the first extrusion screw is 36-50.

[0021] Preferably, the planetary screw segment comprises a central screw, a plurality of small diameter screws and a planetary screw barrel, wherein the central screw is coaxial with the planetary screw barrel and is arranged in parallel in the planetary screw barrel.

[0022] The small diameter screws are distributed around the central screw. The outer wall of the small diameter screw, the outer wall of the central screw and the inner wall of the planetary screw barrel are all provided with spiral teeth.

[0023] The central screw is the active screw, and the circumferentially distributed small-diameter screws mesh with the central screw through spiral teeth to rotate.

[0024] One end of the central screw is fixedly connected to the adjacent end surface of the first extrusion screw, and the other end is fixedly connected to the adjacent end surface of the second extrusion screw in the second single screw segment.

[0025] The diameter of the central screw is the same as that of the first extrusion screw, and the aspect ratio of the central screw is 36-50.

[0026] The length of the small diameter screw is equal to that of the center screw, and the aspect ratio of the small diameter screw is 30-60.

[0027] A vacuum exhaust hole is provided on the outer wall of the end of the planetary screw barrel close to the first single screw segment, and the vacuum exhaust hole is connected to the planetary screw barrel of the planetary screw segment.

[0028] A side feed port is provided on the outer wall of the end of the planetary screw barrel away from the first single screw section, and the side feed port is communicated with the planetary screw barrel of the planetary screw section.

[0029] Preferably, the number of small diameter screws is 4-8.

[0030] Preferably, the second single screw section includes a second screw barrel and a second extrusion screw in the second screw barrel, the second extrusion screw is coaxial with the second screw barrel and is arranged in parallel in the second screw barrel, a liquid injection port is opened on the outer wall of the second screw barrel, the axis of the liquid injection port is perpendicular to the outer wall of the second screw barrel, the liquid injection port is located in the middle of the second extrusion screw and is interconnected with the second screw barrel, the second extrusion screw is fixedly connected to the adjacent end face of the center screw, the other end face of the second extrusion screw is connected to the melt pump, and the aspect ratio of the second extrusion screw is 36-50.

[0031] Preferably, the liquid injection port is located at the lower side of the second single-screw segment barrel, and the axis of the liquid injection port is perpendicular to the outer wall of the second single-screw segment barrel.

[0032] Preferably, the combined screw is integrally formed, which greatly simplifies the forming process of the extruder.

[0033] The utility model has the following beneficial effects:

[0034] The screw extruder in the thermoplastic polyester foaming molding device obtained by the utility model is a multi-screw extruder, which is composed of a screw transmission device, a first single screw segment, a planetary screw segment and a second single screw segment connected in sequence, wherein the first extrusion screw, the center screw and the second extrusion screw in the first single screw segment, the planetary screw segment and the second single screw segment are coaxially fixedly connected in sequence to form a combined screw, the combined screw is coaxial with the extruder barrel and is arranged in parallel in the extruder barrel, the combined screw is fixedly connected to the screw transmission device, and the screw The transmission device provides a circumferential rotation under the rotational torque. Compared with only using a twin-screw extruder as the screw extrusion device of the utility model, the arrangement of the planetary screw segment in the multi-screw extruder has better shear mixing effects in the radial and lateral directions of the screw. In particular, for the planetary screw segment, the radial shear mixing effect is better, the material is blended more evenly in the radial and axial directions, the mixing area is larger, and at the same time, when vacuuming, more water in the material escapes from the vacuum exhaust port at a faster speed in a short time, the material moisture removal efficiency is higher, and the removal effect is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 : A schematic structural diagram of a thermoplastic polyester foaming molding device provided by the utility model.

[0036] In the figure, 1. screw transmission device, 2-1. first extrusion screw, 2-2. feeding port, 3-1. central screw, 3-2. small diameter screw, 3-3. side feeding port, 4-1. second extrusion screw, 4-2. liquid injection port, 5. melt pump, 6. static mixer, 7. foaming head, 8. molding and shaping device. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with the examples. However, it should be understood that the following examples are merely illustrative of the implementation methods of the present invention, and are not intended to limit the scope of the present invention.

[0038] like Figure 1 As shown, a thermoplastic polyester foaming molding device provided by the utility model comprises a multi-screw extruder, a melt pump 5, a static mixer 6, a foaming head 7 and a molding and shaping device 8 connected in sequence.

[0039] The multi-screw extruder comprises a screw transmission device 1, a first single screw segment, a planetary screw segment and a second single screw segment which are connected in sequence.

[0040] The first extrusion screw 2-1, the central screw 3-1, and the second extrusion screw 4-1 in the first single screw segment, the planetary screw segment, and the second single screw segment are coaxially fixedly connected in sequence to form a combined screw.

[0041] The combined screw is coaxial with the extruder barrel and is arranged in parallel in the extruder barrel. The combined screw is fixedly connected to the screw transmission device 1 and rotates circumferentially under the rotation torque provided by the screw transmission device 1.

[0042] The thermoplastic material is heated in the combined screw and transported to the melt pump 5, static mixer 6, foaming head 7 and molding device 8 in sequence.

[0043] The thermoplastic material is fed in turn through the feeding port 2-2 opened at the end of the first single screw section, exhausted through the vacuum exhaust port opened on the outer wall of the planetary screw section barrel, and volatile low-molecular additives (such as chain extenders, plasticizers, etc.) are added through the side feeding port 3-3, and liquid foaming agents such as carbon dioxide, nitrogen, and alkanes are injected through the liquid injection port 4-2 opened on the outer wall of the second single screw section barrel.

[0044] The planetary screw segment accounts for 20%-60% of the total length of the combined screw, and the first single screw segment accounts for 20%-40% of the total length of the combined screw;

[0045] The horizontal distance between the vacuum exhaust port and the side feed port 3-3 along the axis of the extruder barrel accounts for 30-80% of the total length of the planetary screw segment.

[0046] Compared with twin-screw extrusion, planetary screw extrusion has better blending and conveying capabilities. Thermoplastic materials are subjected to greater blending shear force in the planetary screw. In a short period of time, the water vaporizes and is discharged from the thermoplastic material faster and more fully.

[0047] The vacuum exhaust port is arranged in the planetary screw section, so that low molecular weight substances and moisture in the thermoplastic material can be vacuum removed.

[0048] The side feeding port 3-3 of the planetary screw segment is spaced a certain distance from the vacuum exhaust port, so that the moisture can be removed first and then the reactive low-molecular additives can be added. On the one hand, it ensures that the moisture in the thermoplastic material is fully removed, while preventing the low-molecular additives from being drawn out at the vacuum exhaust port, affecting the reaction metering and deteriorating the properties of the obtained foaming molding material.

[0049] In a specific embodiment, the vacuum exhaust port is located on the upper side of the outer wall of the planetary screw section barrel, and the axis of the vacuum exhaust port is perpendicular to the axis of the extruder barrel, which is consistent with the direction of evaporation of water vapor in the thermoplastic material, which is conducive to more complete removal of moisture in the material in a short time.

[0050] In a specific embodiment, the side feed port 3-3 is located at the lower side of the outer wall of the planetary screw section barrel, and the axis of the side feed port 3-3 is perpendicular to the axis of the extruder barrel.

[0051] In a specific embodiment, the first single screw segment includes a first screw barrel and a first extrusion screw 2-1 in the first screw barrel, the first extrusion screw 2-1 is coaxial with the first screw barrel and is arranged parallel to the first screw barrel, the first screw barrel is provided with a feeding port 2-2 near the screw transmission device 1, the feeding port 2-2 is connected to the first screw barrel, one end of the first extrusion screw 2-1 is fixedly connected to the screw transmission device 1, and the other end is fixedly connected to the central screw 3-1 of the planetary screw segment, and the aspect ratio of the first extrusion screw 2-1 is 36-50.

[0052] In a specific embodiment, the planetary screw segment includes a central screw 3-1, a plurality of small diameter screws 3-2 and a planetary screw barrel, wherein the central screw 3-1 is coaxial with the planetary screw barrel and is arranged in parallel in the planetary screw barrel.

[0053] The small diameter screws 3-2 are distributed around the central screw 3-1. The outer wall of the small diameter screw 3-2, the outer wall of the central screw 3-1 and the inner wall of the planetary screw barrel are all provided with spiral teeth.

[0054] The central screw 3-1 is an active screw, and the circumferentially distributed small-diameter screws 3-2 mesh with the central screw 3-1 through spiral teeth and rotate.

[0055] One end of the central screw 3-1 is fixedly connected to the adjacent end surface of the first extrusion screw 2-1, and the other end is fixedly connected to the adjacent end surface of the second extrusion screw 4-1 in the second single screw section.

[0056] The diameter of the central screw 3-1 is the same as that of the first extrusion screw 2-1, and the aspect ratio of the central screw 3-1 is 36-50.

[0057] The length of the small diameter screw 3-2 is equal to that of the central screw 3-1, and the aspect ratio of the small diameter screw 3-2 is 30-60.

[0058] A vacuum exhaust hole is provided on the outer wall of the end of the planetary screw barrel close to the first single screw segment, and the vacuum exhaust hole is connected to the planetary screw barrel of the planetary screw segment.

[0059] A side feed port 3-3 is provided on the outer wall of the end of the planetary screw barrel away from the first single screw section, and the side feed port 3-3 is connected to the planetary screw barrel of the planetary screw section.

[0060] In a specific embodiment, the planetary screw segment can be assembled from a plurality of identical modules, each module accounting for 20-30% of the total length of the entire planetary screw segment.

[0061] In a specific embodiment, the number of small-diameter screws 3-2 is 4-8, so that the thermoplastic material is subjected to a greater blending shear force, ensuring that more moisture is removed from the vacuum exhaust hole more quickly in a short period of time.

[0062] In a specific embodiment, the second single screw section includes a second screw barrel and a second extrusion screw 4-1 in the second screw barrel, the second extrusion screw 4-1 is coaxial with the second screw barrel and is arranged in parallel in the second screw barrel, a liquid injection port 4-2 is opened on the outer wall of the second screw barrel, the axis of the liquid injection port 4-2 is perpendicular to the outer wall of the second screw barrel, the liquid injection port 4-2 is located in the middle of the second extrusion screw 4-1 and is interconnected with the second screw barrel, the second extrusion screw 4-1 is fixedly connected to the adjacent end face of the center screw 3-1, the other end face of the second extrusion screw 4-1 is connected to the melt pump 5, and the aspect ratio of the second extrusion screw 4-1 is 36-50.

[0063] In a specific embodiment, the liquid injection port 4-2 is located on the side of the second single-screw section barrel, and the axis of the liquid injection port 4-2 is perpendicular to the outer wall of the second single-screw section barrel.

[0064] In a specific embodiment, the combined screw is integrally formed, which greatly simplifies the molding process of the extruder.

[0065] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A thermoplastic polyester foaming molding device, characterized in that: The invention comprises a multi-screw extruder, a melt pump (5), a static mixer (6), a foaming head (7) and a molding and shaping device (8) which are connected in sequence. The multi-screw extruder comprises a screw transmission device (1), a first single screw segment, a planetary screw segment and a second single screw segment which are connected in sequence. The first single screw segment, the planetary screw segment, and the first extrusion screw (2-1), the central screw (3-1), and the second extrusion screw (4-1) in the second single screw segment are coaxially fixedly connected in sequence to form a combined screw. The combined screw is coaxial with and parallel to the extruder barrel and is fixedly connected to the screw transmission device (1) and rotates circumferentially under the rotational torque provided by the screw transmission device (1). The thermoplastic material is heated in the combined screw and transported in sequence to the melt pump (5), the static mixer (6), the foaming head (7) and the molding and shaping device (8). The thermoplastic material is sequentially fed through a feed port (2-2) opened at the end of the first single screw section, exhausted through a vacuum exhaust port opened on the outer wall of the barrel of the planetary screw section, and a liquid foaming agent is injected through a liquid injection port (4-2) opened on the outer wall of the barrel of the second single screw section; The planetary screw segment accounts for 20%-60% of the total length of the entire combined screw, and the first single screw segment accounts for 20%-40% of the total length of the entire combined screw.

2. A thermoplastic polyester foaming molding device according to claim 1, characterized in that: The outer wall of the planetary screw segment barrel is provided with a side feeding port (3-3), and the horizontal distance between the vacuum exhaust port and the side feeding port along the axis of the extruder barrel accounts for 30-80% of the total length of the planetary screw segment.

3. A thermoplastic polyester foaming molding device according to claim 1, characterized in that: The vacuum exhaust port is located on the upper side of the outer wall of the planetary screw section barrel, and the axis of the vacuum exhaust port is perpendicular to the axis of the extruder barrel.

4. A thermoplastic polyester foaming molding device according to claim 2, characterized in that: The side feeding port (3-3) is located at the lower side of the outer wall of the planetary screw section barrel, and the axis of the side feeding port (3-3) is perpendicular to the axis of the extruder barrel.

5. A thermoplastic polyester foaming molding device according to claim 1, characterized in that: The first single screw segment comprises a first screw barrel and a first extrusion screw (2-1) in the first screw barrel. The first extrusion screw (2-1) is coaxial with the first screw barrel and is arranged in parallel in the first screw barrel. A feeding port (2-2) is provided in the first screw barrel near the screw transmission device (1). The feeding port (2-2) is connected to the first screw barrel. One end of the first extrusion screw (2-1) is fixedly connected to the screw transmission device (1), and the other end is fixedly connected to the central screw (3-1) of the planetary screw segment. The aspect ratio of the first extrusion screw (2-1) is 36-50.

6. A thermoplastic polyester foaming molding device according to claim 1, characterized in that: The planetary screw segment comprises a central screw (3-1), a plurality of small-diameter screws (3-2) and a planetary screw barrel, wherein the central screw (3-1) is coaxial with the planetary screw barrel and is arranged in parallel in the planetary screw barrel. The small diameter screws (3-2) are distributed around the central screw (3-1), and the outer wall of the small diameter screw (3-2), the outer wall of the central screw (3-1) and the inner wall of the planetary screw barrel are all provided with spiral teeth. The central screw (3-1) is an active screw, and the small-diameter screws (3-2) distributed in the circumferential direction thereof mesh with the central screw (3-1) through spiral teeth to rotate. One end of the central screw (3-1) is fixedly connected to the adjacent end surface of the first extrusion screw (2-1), and the other end is fixedly connected to the adjacent end surface of the second extrusion screw (4-1) in the second single screw segment. The diameter of the central screw (3-1) is the same as that of the first extrusion screw (2-1), and the aspect ratio of the central screw (3-1) is 36-50. The small diameter screw (3-2) is equal in length to the central screw (3-1). A vacuum exhaust hole is provided on the outer wall of the end of the planetary screw barrel close to the first single screw segment, and the vacuum exhaust hole is connected to the planetary screw barrel of the planetary screw segment. A side feed port (3-3) is provided on the outer wall of the end of the planetary screw barrel away from the first single screw section, and the side feed port (3-3) is connected to the planetary screw barrel of the planetary screw section.

7. A thermoplastic polyester foaming molding device according to claim 6, characterized in that: The number of small diameter screws (3-2) is 4-8.

8. A thermoplastic polyester foaming molding device according to claim 1, characterized in that: The second single screw section comprises a second screw barrel and a second extrusion screw (4-1) in the second screw barrel. The second extrusion screw (4-1) is coaxial with the second screw barrel and is arranged in parallel in the second screw barrel. A liquid injection port (4-2) is provided on the outer wall of the second screw barrel. The axis of the liquid injection port (4-2) is perpendicular to the outer wall of the second screw barrel. The liquid injection port (4-2) is located in the middle of the second extrusion screw (4-1) and is connected to the second screw barrel. The second extrusion screw (4-1) is fixedly connected to the adjacent end face of the center screw (3-1). The other end face of the second extrusion screw (4-1) is connected to a melt pump (5). The aspect ratio of the second extrusion screw (4-1) is 36-50.

9. A thermoplastic polyester foaming molding device according to claim 8, characterized in that: The liquid injection port (4-2) is located at the lower side of the second single-screw segment barrel, and the axis of the liquid injection port (4-2) is perpendicular to the outer wall of the second single-screw segment barrel.

10. A thermoplastic polyester foaming molding device according to claim 1, characterized in that: The combined screw is integrally formed.

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