A physical foaming device for polymer particles

Abstract

The present invention relates to a physical foaming device for polymer particles, comprising a foaming reaction cylinder; a rotating and swinging primary foaming mechanism; and an up-and-down vibrating secondary foaming mechanism, wherein the up-and-down vibrating secondary foaming mechanism is placed at the lower side of the rotating and swinging primary foaming mechanism, and the up-and-down vibrating secondary foaming mechanism comprises an upper vibrating mesh screen and a lower vibrating mesh screen arranged in the foaming reaction cylinder, and also comprises a second foaming agent nozzle arranged on the lower end surface of a rotating and swinging disk, wherein the second foaming agent nozzle injects a supercritical fluid foaming agent into the polymer particles falling on the upper vibrating mesh screen and the lower vibrating mesh screen, and at the same time, under the vibration of the upper vibrating mesh screen and the lower vibrating mesh screen, the polymer particles are in an up-and-down circulating motion state, and the supercritical fluid foaming agent is continuously infiltrated into the polymer solid particles again to realize the secondary foaming of the polymer particles. The present invention has the following advantages: solving the technical defects of poor thermal stability of the above-mentioned polymer, uneven size of foaming beads and pore morphology, and poor comprehensive mechanical properties.

Description

Technical Field

[0001] The invention belongs to the field of foaming, and in particular relates to a physical foaming device for polymer particles. Background Art

[0002] The commonly used biodegradable material, polylactic acid resin, is made from starch extracted from renewable plant resources (such as corn). The starch raw material is saccharified to obtain glucose, which is then fermented with glucose and certain bacteria to obtain high-purity lactic acid, and then polymerized to produce polylactic acid of a certain molecular weight. After use, it can be completely decomposed by microorganisms in nature, truly achieving zero pollution. However, polylactic acid resin has the defects of slow crystallization speed and poor thermal stability during processing, and is brittle and breakable. At the same time, it has the defect of foaming behavior due to its easy degradation.

[0003] Therefore, the modification of polylactic acid is a research hotspot for many scholars. Polybutylene terephthalate adipate is a copolymer with good ductility and elongation at break. The blending of polylactic acid and polybutylene terephthalate adipate is a physical modification technique. However, polylactic acid and polybutylene terephthalate have large solubility differences, poor compatibility, and are difficult to mix evenly, which relatively affects the thermal stability of the polymer and causes particles to stick together. At the same time, the foamability is poor, resulting in a small number of pores in the polymer foam material, uneven size and pore morphology of the foamed beads, and poor comprehensive mechanical properties of the foamed beads. Summary of the invention

[0004] The purpose of the present invention is to overcome the above shortcomings and provide a physical foaming device for polymer particles to solve the technical defects of poor thermal stability of the above polymers, uneven size and pore morphology of foamed beads, and poor comprehensive mechanical properties.

[0005] The purpose of the present invention is achieved through the following technical solutions: a physical foaming device for polymer particles, comprising:

[0006] A foaming reaction tube, wherein the inner wall of the foaming reaction tube is provided with a heating wire, and the side wall of the foaming reaction tube is provided with a raw material inlet pipe and a foaming agent inlet pipe;

[0007] The rotating and swinging primary foaming mechanism comprises a limit support frame arranged at the upper side position inside the foaming reaction cylinder, a rotating swinging disk is embedded in the limit support frame, the discharge end of the raw material inlet pipe is arranged corresponding to the rotating swinging disk, the rotating swinging disk comprises a rotating sphere that is mutually embedded with the limit support frame and a disk body that horizontally passes through the center of the rotating sphere, the limit support frame is provided with a driving component for driving the rotating swinging disk to rotate and swing, the driving component comprises a reduction motor 1 arranged on the limit support frame and a connecting column vertically arranged at the upper end of the rotating sphere, the connecting column and the driving end of the reduction motor 1 are connected with a driving shaft, the driving shaft is arranged perpendicular to the connecting column, the reduction motor 1 is coaxially arranged with the rotating sphere, the outer circumference of the connecting column is provided with a plurality of rotating baffles, and the side wall of the rotating baffle has A plurality of foaming agent nozzles are provided, and a material blocking opening and closing assembly is provided around the disc body; when polymer particles are fed into the rotating swing disc from the raw material inlet pipe, the material blocking opening and closing assembly is in a closed state, and a reduction motor is started, driving the rotating swing disc to rotate and swing and the rotating baffle to rotate in a circle, thereby driving the polymer particles in the rotating swing disc to mix and stir, and promoting the recrystallization of the polymer particles through mutual collision and friction, and at the same time, a foaming agent nozzle injects a supercritical fluid foaming agent into the polymer particles in the rotating swing disc, and the supercritical fluid foaming agent continuously penetrates into the polymer particles to realize the initial foaming; when the polymer particles are mixed and stirred in the rotating swing disc for a certain period of time, the material blocking opening and closing assembly is in an open state, and the polymer particles are fed downward through the material blocking opening and closing assembly under the tilting action of the rotating swing disc;

[0008] The up-and-down vibrating re-foaming mechanism is arranged at the lower side of the rotating and swinging primary foaming mechanism, and comprises an upper vibrating mesh screen and a lower vibrating mesh screen arranged in the foaming reaction cylinder, and also comprises a second foaming agent nozzle arranged on the lower end surface of the rotating and swinging disk, and the second foaming agent nozzle injects a supercritical fluid foaming agent into the polymer particles falling on the upper vibrating mesh screen and the lower vibrating mesh screen, and at the same time, under the vibration action of the upper vibrating mesh screen and the lower vibrating mesh screen, the polymer particles are in an up-and-down circulating motion state, and the supercritical fluid foaming agent is continuously infiltrated into the polymer solid particles again to realize the re-foaming of the polymer particles.

[0009] A further improvement of the present invention is that the material blocking opening and closing assembly includes an outer ring fixedly arranged on the outer circumference of the disk body and an inner ring rotatably arranged on the inner wall of the outer ring, the upper end surface of the disk body has a ring groove embedded in the bottom of the inner ring, the bottom inner wall of the inner ring has a gear ring part, and the disk body is provided with a reduction motor 2, the driving shaft of the reduction motor 2 is provided with a gear 1, and a gear 2 is provided between the gear 1 and the gear ring part, the gear 2 is connected to the disk body through a rotating shaft, the gear 2 and the gear 1 and the gear ring part are meshed with each other, and the outer ring and the inner ring are provided with a plurality of evenly distributed material feeding through holes, when the reduction motor 2 is started forward, the inner ring rotates, so that the material feeding through holes on the outer ring and the inner ring are connected in sequence, at this time, the material blocking opening and closing assembly is in an open state, and when the reduction motor 2 is started reversely, the inner ring rotates, so that the material feeding through holes on the outer ring and the inner ring are staggered and closed in sequence, and at this time, the material blocking opening and closing assembly is in a closed state.

[0010] A further improvement of the present invention is that the driving assembly also includes a plurality of telescopic rods vertically penetrating the limit support frame, the upper ends of the telescopic rods are fixedly connected to the foaming reaction cylinder, and the lower ends of the telescopic rods have spherical parts, which contact the lower end surface of the disk.

[0011] A further improvement of the present invention is that the telescopic rod includes an upper rod body fixedly connected to the foaming reaction cylinder and a lower rod body fixedly passing through the limit support frame, the lower rod body is provided with a through groove for accommodating the upper rod body to vertically pass through, a spring is provided in the through groove, the upper end of the spring is fixedly connected to the upper rod body, and the lower end of the spring is fixedly connected to the bottom of the through groove, when the disk body rotates and swings, the spring in the corresponding telescopic rod in contact with the disk body is driven to expand and contract, thereby realizing the vertical limitation of the periphery of the disk body during the rotation and swinging process.

[0012] A further improvement of the present invention is that the upper and lower vibration re-foaming mechanism also includes fixed blocks arranged on both sides of the inner wall of the foaming reaction cylinder and connected to the upper vibrating mesh screen, a material guide cylinder is provided between the fixed blocks on both sides, the fixed blocks on both sides are movably connected to the two sides of the upper vibrating mesh screen through a vertically arranged spring piece 1, the side end of the upper vibrating mesh screen is movably connected to the side end of the lower vibrating mesh screen through a spring piece 2, one end of the upper vibrating mesh screen is tilted downward toward the position of the other end, one end of the lower vibrating mesh screen close to the lower side position of the upper vibrating mesh screen is tilted downward toward the position of the other end of the lower vibrating mesh screen, the inclination angle of the upper vibrating mesh screen and the lower vibrating mesh screen is 10°-15°, and any fixed block is connected to a vibration component for synchronously driving the upper vibrating mesh screen and the lower vibrating mesh screen to vibrate.

[0013] A further improvement of the present invention is that the vibration assembly includes a dual-axis motor placed in any fixed block, the two driving shafts of the dual-axis motor are distributed along the radial direction of the upper vibrating screen, the outer end of the driving shaft is placed outside the fixed block and is eccentrically connected to a crank, and also includes a shaft rod arranged at one end of the lower vibrating screen away from the dual-axis motor, the side part of one end of the lower vibrating screen has a shaft rod seat for accommodating the shaft rod to pass through, and the two side ends of the shaft rod are respectively movably connected to the two cranks through connecting rods.

[0014] A further improvement of the present invention is that the foaming agent inlet pipe is connected with the foaming agent nozzle 1 and the foaming agent nozzle 2.

[0015] A further improvement of the present invention is that a plurality of rotating baffles are sequentially staggered and arranged on the outer circumference of the connecting column, and the rotating baffles are arranged obliquely to the axis of the connecting column.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] In the present invention, when the polymer particles are foamed, the rotating and swinging of the primary foaming mechanism is first performed, and the polymer particles originally obtained by alcohol-water separation are mixed and de-alcoholized again, which provides a basic guarantee for the subsequent foaming quality. The polymer particles after de-alcoholization collide and rub against each other in the circumferential direction, and the supercritical fluid foaming agent sprayed by the foaming agent nozzle continuously penetrates into the polymer particles in the process of mutual collision movement, so as to realize the initial foaming of the initial polymer particles. The polymer particles after the initial foaming pass through the material blocking opening and closing component to the upper and lower vibrating secondary foaming mechanism, and at this time, the polymer particles are under the action of the upper and lower vibrating mesh screens. It is in an up and down circulating motion state, and the foaming agent of the supercritical fluid continuously penetrates into the polymer solid particles. The foamed beads obtained after saturation and pressure relief have a high expansion ratio and a good pore structure. The high-temperature saturation process and vibration promote the recrystallization of the semi-crystalline polymer, increase the crystallization rate between polymer molecules, and ensure the heat resistance and foaming performance of the foamed beads. Secondly, the polymer solid particles are depressurized and cooled after foaming for a certain period of time. The physical vibration foaming unit vibrates the solid particles up and down, accelerates the cooling rate, and quickly cools and solidifies to maintain the phase morphology, heat resistance and comprehensive mechanical properties of the foamed beads. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of a physical foaming device for polymer particles of the present invention.

[0019] Figure 2 for Figure 1 Schematic diagram of the structure of the medium rotating and swinging primary foaming mechanism.

[0020] Figure 3 for Figure 2 middle Figure 2 Schematic diagram of the structure of the middle stop opening and closing assembly.

[0021] Figure 4 for Figure 1 Schematic diagram of the structure of the up and down vibration re-foaming mechanism.

[0022] Figure 5 for Figure 4 Top view of the .

[0023] Figure 6 for Figure 4 Schematic diagram of the structure of the middle and lower vibrating mesh screen.

[0024] Numbers in the figure:

[0025] 1- foaming reaction cylinder, 2- rotating and swinging initial foaming mechanism, 3- up and down vibration secondary foaming mechanism;

[0026] 11-raw material inlet pipe, 12-foaming agent inlet pipe;

[0027] 21-limiting support frame, 22-rotating swing plate, 23-driving assembly, 24-blocking opening and closing assembly; 221-rotating ball, 222-plate; 231-reduction motor 1, 232-connecting column, 233-driving shaft, 234-rotating baffle, 235-foaming agent nozzle 1, 236-telescopic rod, 237-ball part; 241-outer ring, 242-inner ring, 243-ring groove, 244-gear ring part, 245-gear 1, 246-reduction motor 2, 247-gear 2, 248-feeding through hole, 249-rotating shaft; 2361-upper rod, 2362-lower rod, 2363-through groove, 2364-spring;

[0028] 31-upper vibrating mesh screen, 32-lower vibrating mesh screen, 33-foaming agent nozzle 2; 311-fixed block, 312-material guide cylinder, 313-spring piece 1, 314-spring piece 2, 315-double-axis motor, 316-crank, 317-shaft rod, 318-shaft rod seat, 319-connecting rod, 3110-driving shaft. DETAILED DESCRIPTION

[0029] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0030] In the description of the present invention, it is necessary to understand that terms indicating orientation or positional relationships, such as orientation or positional relationships based on the drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the structure or unit referred to must have a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0031] In the present invention, unless otherwise clearly stipulated and limited, terms such as "connected", "provided with", "having" and the like 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 said to be a mechanical connection, or it can be directly connected, or it can be connected through an intermediate medium. For those skilled in the art, the basic meaning of the above terms in the present invention can be understood according to the specific circumstances.

[0032] A physical foaming device for polymer particles, such as Figure 1 Shown, including

[0033] A foaming reaction tube 1, wherein the inner wall of the foaming reaction tube 1 is provided with a heating wire, and the side wall of the foaming reaction tube 1 is provided with a raw material inlet pipe 11 and a foaming agent inlet pipe 12;

[0034] Rotating and swinging primary foaming mechanism 2, refer to Figure 2 The rotating and swinging primary foaming mechanism 2 includes a limiting support frame 21 arranged at the upper side position inside the foaming reaction cylinder 1, a rotating swinging disk 22 is embedded in the limiting support frame 21, and the discharge end of the raw material inlet pipe 11 is arranged corresponding to the rotating swinging disk 22, the rotating swinging disk 22 includes a rotating sphere 221 that is mutually embedded with the limiting support frame 21 and a disk body 222 that horizontally passes through the center of the rotating sphere 221, and the limiting support frame 21 is provided with a driving component 23 for driving the rotating swinging disk 22 to rotate and swing, the driving component 23 includes a reduction motor 231 arranged on the limiting support frame 21 and a connecting column 232 vertically arranged at the upper end of the rotating sphere 221, the connecting column 232 and the driving end of the reduction motor 231 are connected with a driving shaft 233, the driving shaft 233 is arranged perpendicular to the connecting column 232, the reduction motor 231 is coaxially arranged with the rotating sphere 221, and the outer circumference of the connecting column 232 has a plurality of rotating baffles 23 4. The side wall of the rotating baffle 234 is provided with a plurality of foaming agent nozzles 235, and the disc body 222 is provided with a material blocking opening and closing assembly 24 around it; when the polymer particles are fed into the rotating swing disc 22 from the raw material inlet pipe 11, the material blocking opening and closing assembly 24 is in a closed state, and the reduction motor 231 is started to drive the rotating swing disc 22 to rotate and swing and the rotating baffle 234 to rotate in a circle, thereby driving the polymer particles in the rotating swing disc 22 to mix and stir, and promoting the recrystallization of the polymer particles through mutual collision and friction, and at the same time, the foaming agent nozzle 235 injects a supercritical fluid foaming agent into the polymer particles in the rotating swing disc 22, and the supercritical fluid foaming agent continuously penetrates into the polymer particles to realize the initial foaming; when the polymer particles are mixed and stirred in the rotating swing disc 22 for a certain period of time, the material blocking opening and closing assembly 24 is in an open state, and the polymer particles are fed downward through the material blocking opening and closing assembly 24 under the tilting action of the rotating swing disc 22;

[0035] The up-and-down vibrating re-foaming mechanism 3 is placed at the lower side of the rotating and swinging primary foaming mechanism 2. The up-and-down vibrating re-foaming mechanism 3 includes an upper vibrating mesh screen 31 and a lower vibrating mesh screen 32 arranged in the foaming reaction tube 1, and also includes a foaming agent nozzle 2 33 arranged on the lower end surface of the rotating and swinging disk 22. The foaming agent nozzle 2 33 injects a supercritical fluid foaming agent into the polymer particles falling on the upper vibrating mesh screen 31 and the lower vibrating mesh screen 32. At the same time, under the vibration action of the upper vibrating mesh screen 31 and the lower vibrating mesh screen 32, the polymer particles are in an up-and-down circulating motion state, and the supercritical fluid foaming agent continuously penetrates into the polymer solid particles again to realize the re-foaming of the polymer particles.

[0036] It should be noted that the physical particles are obtained by polymerizing the raw materials through nitrogen, alcohol water and solvent and then separating the alcohol water. The polymer particles need to be foamed subsequently, and the physical foaming equipment in this application is used for the physical foaming of the polymer particles.

[0037] In the present invention, when the polymer particles are foamed, the polymer particles originally obtained by alcohol-water separation are mixed and de-alcoholized again through the rotation and swing of the primary foaming mechanism 2, which provides a basic guarantee for the subsequent foaming quality. The polymer particles after de-alcoholization collide and rub against each other in the circumferential direction, and the supercritical fluid foaming agent sprayed by the foaming agent nozzle 235 continuously penetrates into the polymer particles in the process of mutual collision movement, thereby realizing the preliminary foaming of the preliminary polymer particles. The polymer particles after the preliminary foaming pass through the material blocking opening and closing component 24 to the upper and lower vibration secondary foaming mechanism 3. At this time, the polymer particles are in the upper and lower vibration nets. Under the action of the sieve, it is in an up and down circulating motion state, and the foaming agent of the supercritical fluid continuously penetrates into the polymer solid particles. The foamed beads obtained after saturation and pressure relief have a high expansion ratio and a good pore structure. The high-temperature saturation process and vibration promote the recrystallization of the semi-crystalline polymer, increase the crystallization rate between polymer molecules, and ensure the heat resistance and foaming performance of the foamed beads; secondly, after the polymer solid particles are foamed for a certain period of time, the pressure is relieved and cooled, and the up and down vibration of the mesh screen on the foaming of the solid particles accelerates the cooling rate, and the rapid cooling and solidification maintains the phase morphology, heat resistance and comprehensive mechanical properties of the foamed beads.

[0038] Based on this embodiment, refer to Figure 3The material blocking opening and closing assembly 24 includes an outer ring 241 fixedly arranged on the outer circumference of the disk body 222 and an inner ring 242 rotatably arranged on the inner wall of the outer ring 241. The upper end surface of the disk body 222 has an annular groove 243 for accommodating the bottom of the inner ring 242. The bottom inner wall of the inner ring 242 has a gear ring portion 244. The disk body 222 has a reduction motor 246. The drive shaft of the reduction motor 246 has a gear 1 245. There is a gear 247 between the gear 1 245 and the gear ring portion 244. The gear 247 is connected to the disk body 222 through a rotating shaft 249. The second gear 247 is meshed with the gear one 245 and the gear ring part 244. The outer ring 241 and the inner ring 242 are provided with a plurality of evenly distributed feed holes 248. When the reduction motor 246 is started in the forward direction, the inner ring 242 rotates, so that the feed holes 248 on the outer ring 241 and the inner ring 242 are connected in sequence. At this time, the material blocking opening and closing component 24 is in an open state. When the reduction motor 246 is started in the reverse direction, the inner ring 242 rotates, so that the feed holes 248 on the outer ring 241 and the inner ring 242 are staggered and closed in sequence. At this time, the material blocking opening and closing component 24 is in a closed state.

[0039] In the present application, when the material blocking opening and closing component 24 is in a closed state, that is, the material discharge hole 248 on the inner ring 242 is not connected to the material discharge hole 248 on the outer ring 241, at this time, the polymer particles are fully mixed in the rotating swing disk 22 as it rotates and swings; and when the material blocking opening and closing component 24 is in an open state, that is, the material discharge hole 248 on the inner ring 242 and the material discharge hole 248 on the outer ring 241 correspond to each other in sequence, at this time, the polymer particles are discharged into the foaming mechanism again by the upward and downward vibration under the rotation and swing of the rotating swing disk 22.

[0040] Based on this embodiment, the driving assembly 23 also includes a plurality of telescopic rods 236 vertically penetrating the limiting support frame 21, the upper end of the telescopic rod 236 is fixedly connected to the foaming reaction cylinder 1, and the lower end of the telescopic rod 236 has a spherical portion 237, and the spherical portion 237 contacts the lower end surface of the disk body 222.

[0041] Specifically, the telescopic rod 236 includes an upper rod body 2361 fixedly connected to the foaming reaction cylinder 1 and a lower rod body 2362 fixedly passing through the limit support frame 21. The lower rod body 2362 has a through groove 2363 for vertically passing the upper rod body 2361. The through groove 2363 has a spring 2364. The upper end of the spring 2364 is fixedly connected to the upper rod body 2361, and the lower end of the spring 2364 is fixedly connected to the bottom of the through groove 2363. When the disk body 222 rotates and swings, the spring 2364 in the corresponding telescopic rod 236 in contact with the disk body 222 is driven to expand and contract, thereby realizing the peripheral vertical limitation of the disk body 222 during the rotation and swinging process.

[0042] Based on this embodiment, refer to Figure 4 The upper and lower vibration re-foaming mechanism 3 also includes fixed blocks 311 arranged on both sides of the inner wall of the foaming reaction cylinder 1 and connected to the upper vibrating mesh screen 31, and a material guide cylinder 312 is provided between the fixed blocks 311 on both sides. The fixed blocks 311 on both sides are movably connected to the two sides of the upper vibrating mesh screen 31 through vertically arranged spring pieces 1 313 respectively, and the side ends of the upper vibrating mesh screen 31 and the side ends of the lower vibrating mesh screen 32 are movably connected through spring pieces 2 314. One end of the upper vibrating mesh screen 31 is tilted downward toward the position of the other end, and one end of the lower vibrating mesh screen 32 close to the lower side position of the upper vibrating mesh screen 31 is tilted downward toward the position of the other end of the lower vibrating mesh screen 32. The inclination angle of the upper vibrating mesh screen 31 and the lower vibrating mesh screen 32 is 10°-15°. Any fixed block 311 is connected to a vibration component for synchronously driving the upper vibrating mesh screen 31 and the lower vibrating mesh screen 32 to vibrate.

[0043] Based on this embodiment, refer to Figure 5 , Figure 6 The vibration assembly includes a dual-axis motor 315 placed in any fixed block 311, and the two driving shafts of the dual-axis motor 315 are distributed along the radial direction of the upper vibration screen 31. The outer end of the driving shaft is placed outside the fixed block 311 and is eccentrically connected to a crank 316. It also includes a shaft rod 317 arranged at one end of the lower vibration screen 32 away from the dual-axis motor 315. The side portion of one end of the lower vibration screen 32 has a shaft rod seat 318 for accommodating the shaft rod 317 to pass through. The two side ends of the shaft rod 317 are respectively connected to the two cranks 316 through connecting rods 319 to achieve active connection.

[0044] Regarding the upper vibrating mesh screen 31 and the lower vibrating mesh screen 32:

[0045] The polymer particles are placed on the upper vibrating screen 31 through the guide barrel 312, and the double-axis motor 315 is started to drive the cranks 316 on the two drive shafts 3110 to rotate. The connecting rod 319 jumps up and down slightly under the action of the crank 316, and the lower vibrating screen 32 connected to the connecting rod 319 vibrates up and down slightly. Since the upper vibrating screen 31 and the lower vibrating screen 32 are movably connected through the spring piece 2 314, and the upper vibrating screen 31 and the fixed block 311 are movably connected through the spring piece 1 313, the upper vibrating screen 31 and the lower vibrating screen 32 can be vibrated up and down.

[0046] The inclination angle of the upper vibrating mesh screen 31 and the lower vibrating mesh screen 32 is 10°-15°, and the polymer particles on the upper vibrating mesh screen 31 gradually move to the lower vibrating mesh screen 32 as the upper vibrating mesh screen 31 vibrates; especially during physical foaming, the polymer particles vibrate on the upper vibrating mesh screen 31, and since the foaming agent nozzle 2 33 vibrates up and down and injects the supercritical fluid foaming agent into the polymer particles on the foaming mechanism 3 again, a certain resistance is generated for the polymer particles to move to the lower vibrating mesh screen 32, avoiding falling too fast and affecting the foaming efficiency. Secondly, the foaming agent injected into the supercritical fluid is evenly diffused around the polymer particles through the upper vibrating mesh screen 31 and the lower vibrating mesh screen 32, effectively realizing the uniform diffusion and rapid saturation of the foaming agent, and ensuring the uniformity of the size of the foamed beads and the regularity of the pore morphology.

[0047] It should be noted that the foaming agent nozzle 2 33 is arranged on the lower end surface of the rotating swing disk 22. Therefore, the foaming agent of the supercritical fluid is sprayed toward the upward and downward vibrating mesh screen as the rotating swing disk 22 rotates and swings, thereby changing the traditional foaming method with a single spray direction, further realizing the uniform diffusion and rapid saturation of the foaming agent, and ensuring the uniformity of the size of the foaming beads and the regularity of the pore morphology.

[0048] The design of the rotating swinging disk 22 has the following three advantages: 1. It rotates and swings at a uniform speed to mix and remove alcohol from the polymer particles before foaming; 2. During the rotating and swinging process, the foaming agent nozzle 235 on the rotating baffle 234 performs preliminary foaming on the polymer particles, which prolongs the foaming time of the polymer particles and ensures the adequacy of the foaming; 3. The foaming agent nozzle 233 is set on the lower end surface of the rotating swinging disk to facilitate the uniform diffusion of the foaming agent during the second foaming.

[0049] On the basis of this embodiment, the foaming agent inlet pipe 12 is connected with the foaming agent nozzle 1 235 and the foaming agent nozzle 2 33 .

[0050] On the basis of this embodiment, a plurality of rotating baffles 234 are staggered in sequence up and down on the outer circumference of the connecting column 232 , and the rotating baffles 234 are arranged to be inclined to the axis of the connecting column 232 .

[0051] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A physical foaming device for polymer particles, characterized in that: include A foaming reaction cylinder (1), wherein the inner wall of the foaming reaction cylinder (1) is provided with a heating wire, and the side wall of the foaming reaction cylinder (1) is provided with a raw material inlet pipe (11) and a foaming agent inlet pipe (12); A rotating and swinging primary foaming mechanism (2), the rotating and swinging primary foaming mechanism (2) comprising a limit support frame (21) arranged at an upper position inside a foaming reaction cylinder (1), a rotating and swinging disc (22) being embedded in the limit support frame (21), a discharge end of the raw material inlet pipe (11) being arranged corresponding to the rotating and swinging disc (22), the rotating and swinging disc (22) comprising a rotating sphere (221) interlocked with the limit support frame (21) and a disc (222) horizontally penetrating the center of the rotating sphere (221), the limit support frame (2 1) has a driving assembly (23) for driving the rotating swing plate (22) to rotate and swing, the driving assembly (23) comprising a reduction motor (231) arranged on the limit support frame (21) and a connecting column (232) vertically arranged on the upper end of the rotating sphere (221), the connecting column (232) and the driving end of the reduction motor (231) are connected to a driving shaft (233), the driving shaft (233) is arranged perpendicular to the connecting column (232), the reduction motor (231) and the rotating sphere (221) are coaxially arranged, The outer circumference of the connecting column (232) is provided with a plurality of rotating baffles (234), the side wall of the rotating baffle (234) is provided with a plurality of foaming agent nozzles (235), and the periphery of the disk body (222) is provided with a material baffle opening and closing assembly (24); when polymer particles are discharged from the raw material inlet pipe (11) into the rotating swing disk (22), the material baffle opening and closing assembly (24) is in a closed state, and the reduction motor (231) is started, driving the rotating swing disk (22) to rotate and swing and the rotating baffle (234) to rotate in a circle, thereby driving the rotating swing disk ( The polymer particles in the rotating swing disk (22) are mixed and stirred, and the recrystallization of the polymer particles is promoted by mutual collision and friction. At the same time, the foaming agent nozzle (235) injects a supercritical fluid foaming agent into the polymer particles in the rotating swing disk (22), and the supercritical fluid foaming agent continuously penetrates into the polymer particles to achieve initial foaming; after the polymer particles are mixed and stirred in the rotating swing disk (22) for a certain period of time, the material blocking opening and closing component (24) is in an open state, and the polymer particles are fed downward through the material blocking opening and closing component (24) under the tilting action of the rotating swing disk (22);The material blocking opening and closing assembly (24) comprises an outer ring (241) fixedly arranged on the outer circumference of a disk body (222) and an inner ring (242) rotatably arranged on the inner wall of the outer ring (241); the upper end surface of the disk body (222) comprises an annular groove (243) for accommodating the bottom of the inner ring (242); the bottom inner wall of the inner ring (242) comprises a gear ring portion (244); a reduction motor 2 (246) is arranged in the disk body (222); a gear 1 (245) is arranged on the driving shaft of the reduction motor 2 (246); a gear 2 (247) is arranged between the gear 1 (245) and the gear ring portion (244); the gear 2 (247) is connected to the disk body (222) via a rotating shaft (249). ), the gear 2 (247) meshes with the gear 1 (245) and the gear ring (244), and the outer ring (241) and the inner ring (242) are provided with a plurality of evenly distributed feed holes (248). When the reduction motor 2 (246) is started in the forward direction, the inner ring (242) rotates, so that the feed holes (248) on the outer ring (241) and the inner ring (242) are connected in sequence, and the material blocking opening and closing component (24) is in an open state. When the reduction motor 2 (246) is started in the reverse direction, the inner ring (242) rotates, so that the feed holes (248) on the outer ring (241) and the inner ring (242) are staggered and closed in sequence, and the material blocking opening and closing component (24) is in a closed state. An up-and-down vibrating re-foaming mechanism (3) is disposed at a lower side of the rotating and swinging primary foaming mechanism (2). The up-and-down vibrating re-foaming mechanism (3) comprises an upper vibrating mesh screen (31) and a lower vibrating mesh screen (32) disposed in a foaming reaction cylinder (1), and further comprises a second foaming agent nozzle (33) disposed on the lower end surface of the rotating and swinging disk (22). The second foaming agent nozzle (33) injects a supercritical fluid foaming agent into polymer particles falling onto the upper vibrating mesh screen (31) and the lower vibrating mesh screen (32). At the same time, under the vibration action of the upper vibrating mesh screen (31) and the lower vibrating mesh screen (32), the polymer particles are placed in an up-and-down circulating motion state, and the supercritical fluid foaming agent is continuously infiltrated into the polymer solid particles again to achieve re-foaming of the polymer particles.

2. A physical foaming device for polymer particles according to claim 1, characterized in that: The driving assembly (23) further comprises a plurality of telescopic rods (236) vertically penetrating the position-limiting support frame (21); the upper ends of the telescopic rods (236) are fixedly connected to the foaming reaction cylinder (1); the lower ends of the telescopic rods (236) have spherical portions (237); and the spherical portions (237) are in contact with the lower end surface of the disk body (222).

3. A physical foaming device for polymer particles according to claim 2, characterized in that: The telescopic rod (236) comprises an upper rod body (2361) fixedly connected to the foaming reaction cylinder (1) and a lower rod body (2362) fixedly penetrating the limit support frame (21); the lower rod body (2362) is provided with a through slot (2363) for accommodating the upper rod body (2361) to vertically penetrate; a spring (2364) is provided in the through slot (2363); the upper end of the spring (2364) is fixedly connected to the upper rod body (2361); the lower end of the spring (2364) is fixedly connected to the bottom of the through slot (2363); when the disc body (222) rotates and swings, the spring (2364) in the corresponding telescopic rod (236) in contact with the disc body (222) is driven to expand and contract, thereby realizing the vertical limit of the periphery of the disc body (222) during the rotation and swinging process.

4. A physical foaming device for polymer particles according to claim 3, characterized in that: The up-and-down vibration re-foaming mechanism (3) further comprises fixed blocks (311) arranged on both sides of the inner wall of the foaming reaction cylinder (1) and connected to the upper vibrating mesh screen (31), a material guide cylinder (312) is provided between the fixed blocks (311) on both sides, the fixed blocks (311) on both sides are movably connected to both sides of the upper vibrating mesh screen (31) via spring pieces 1 (313) arranged vertically, and the side ends of the upper vibrating mesh screen (31) and the side ends of the lower vibrating mesh screen (32) are connected via spring pieces 2 (314). The upper vibrating mesh screen (31) is movably connected, one end of the upper vibrating mesh screen (31) is tilted downward toward the position of the other end, one end of the lower vibrating mesh screen (32) close to the lower side of the upper vibrating mesh screen (31) is tilted downward toward the position of the other end of the lower vibrating mesh screen (32), the inclination angle of the upper vibrating mesh screen (31) and the lower vibrating mesh screen (32) is 10°-15°, and any fixed block (311) is connected to a vibration component for synchronously driving the upper vibrating mesh screen (31) and the lower vibrating mesh screen (32) to vibrate.

5. A physical foaming device for polymer particles according to claim 4, characterized in that: The vibration assembly comprises a dual-axis motor (315) disposed in any one of the fixed blocks (311), the two driving shafts of the dual-axis motor (315) being distributed along the radial direction of the upper vibration screen (31), the outer ends of the driving shafts being disposed outside the fixed block (311) and eccentrically connected to a crank (316), and further comprising a shaft (317) disposed at one end of the lower vibration screen (32) away from the dual-axis motor (315), the side portion of one end of the lower vibration screen (32) comprising a shaft seat (318) for accommodating the shaft (317) to pass through, and the two side ends of the shaft (317) being movably connected to the two cranks (316) via connecting rods (319).

6. A physical foaming device for polymer particles according to claim 5, characterized in that: The foaming agent inlet pipe (12) is in communication with the foaming agent nozzle 1 (235) and the foaming agent nozzle 2 (33).

7. A physical foaming device for polymer particles according to claim 6, characterized in that: The plurality of rotating baffles (234) are sequentially arranged in an up-and-down manner and staggered on the outer circumference of the connecting column (232); the rotating baffles (234) are arranged obliquely to the axis of the connecting column (232).

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