Constant-temperature and speed-control crystallizing machine for forming PLA (polylactic acid) suction pipe for waste recovery

Abstract

The invention discloses a constant-temperature and speed-control crystallizer for forming a PLA suction tube for waste recovery, and relates to the technical field of suction tube production, particles of recovered raw materials are heated and sheared into PLA molten materials through a plastic plasticizing device, the PLA molten materials are extruded into a tubular structure through a plastic extrusion device, and the constant-temperature and speed-control crystallizer comprises a cooling crystallization mechanism, a sectional conveying mechanism and a sorting mechanism. The cooling crystallization mechanism comprises a water tank, the tail end of the water tank is high, the head end of the water tank is low, and the head end of the water tank is aligned with a die head outlet of the plastic extrusion device. The water temperature can be adjusted through the electric heater on the inner side of the water tank, the cooling water tank forms water circulation through the drainage pipe and the water supply pipe, the water pump adjusts the water supply amount to control the cooling speed, and the cooling fins keep the water temperature stable; the online infrared spectrometer detects the crystallization degree in real time, the constant temperature value and the cooling speed are adjusted in combination with the detection result, the arrangement of PLA molecular chains is accurately regulated and controlled, the situation that the suction pipe is too soft or too hard due to unbalance of the crystallization degree is avoided, and it is guaranteed that the forming quality is stable.

Description

Technical Field

[0001] This invention relates to the field of straw production technology, specifically to a temperature-controlled and speed-controlled crystallizer for forming PLA straws for waste recycling. Background Technology

[0002] PLA straw forming is the process of processing polylactic acid (PLA) material into straws. First, because PLA granules may vary in hardness and size, they need to be mixed in a mixing drum using a mixer. After uniform mixing, the raw material is poured into the feed inlet, and under the extrusion action of a screw, the PLA granules melt under high temperature and are extruded through a die head to form hollow strips. Next, the extruded PLA strips are guided into a water tank, where they are cooled and shaped using a sizing groove to obtain straw strips of standard diameter. Finally, the straw strips are cut to fixed lengths in a cutting machine, and after quality inspections of inner diameter, thickness, length, roundness, etc., qualified PLA straws are ready for shipment.

[0003] In straw production, the crystallization process is the core element determining product quality, and it is influenced by a combination of parameters. Among these, cooling temperature and crystallization rate directly affect the hardness of the formed straw. Straws that are too soft or too hard have obvious defects. Therefore, maintaining a constant crystallization temperature and precisely controlling the cooling rate are crucial.

[0004] If manufacturing defects in straws are caused by process issues, recycling can effectively reduce raw material costs. However, existing processes lack the design to use the recycling process to provide feedback and adjust crystallization process parameters. This makes it difficult to optimize problems in the crystallization process in a timely manner, thereby affecting the stable improvement of production efficiency and product quality. Summary of the Invention

[0005] The purpose of this invention is to provide a constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling, wherein the recycled raw material particles are heated and sheared into PLA molten material by a plasticizing device, and the PLA molten material is extruded into a tubular structure by a plastic extrusion device. The crystallizer includes a cooling crystallization mechanism, a segmented conveying mechanism, and a sorting mechanism. The cooling crystallization mechanism includes a water tank, the inner cavity of which is inclined from the tail end to the head end. The head end of the water tank is aligned with the die outlet of the plastic extrusion device. Several guide rollers are provided on the upper surface of the water tank, and a traction roller is provided at the tail end of the water tank. A servo motor is provided on the outer wall of the water tank, and the servo motor drives the traction roller to move the straw.

[0007] Electric heaters are installed on the two inner walls of the water tank, and a cooling water tank is installed on the outer side of the cooling crystallization mechanism. A drain pipe and a water supply pipe are connected to the surface of the cooling water tank. The drain pipe is connected to the bottom wall at the beginning of the water tank, and the opening of the water supply pipe is set above the end of the water tank. A water pump is installed at the other end of the water supply pipe, and a partition dike is installed inside the end of the water tank.

[0008] The sorting mechanism is installed at the tail end of the water tank. The segmented conveying mechanism is located between the cooling crystallization mechanism and the sorting mechanism. The segmented conveying mechanism is used to convey the cut-off suction tubes one by one to the sorting mechanism. The sorting mechanism includes two side seats, with a fixed shaft and a movable shaft rotatably connected between the two side seats. A movable groove is opened on the upper surface of the side seats. A positioning screw is movably connected to the outer side wall of the movable shaft. Conical rollers are installed on the outer side walls of both the fixed shaft and the movable shaft. The fixed shaft and the movable shaft always remain parallel, and the gap between the two conical rollers changes from narrow to wide.

[0009] Preferably, a recycling mechanism is provided below the sorting mechanism. The recycling mechanism includes a recycling bin, which has two partitions inside. A weighing device is provided at the bottom of the recycling bin, and movable windows are provided on the side walls of the recycling bin at three compartment positions.

[0010] Preferably, the segmented conveying mechanism includes a guide ramp and a guide trough, both of which are placed at an incline. The suction tube falls from the guide trough into the guide ramp and then rolls down the guide ramp.

[0011] Preferably, a second servo motor is provided below the bottom of the guide slope, a cam is installed at the output end of the second servo motor, and a rotating seat is rotatably connected to the outer wall of the guide slope, with the surface of the cam contacting the lower surface of the rotating seat.

[0012] Preferably, the rotating seat is a semi-enclosed structure with three sides closed, and a partition column one is installed at the top of the open side, and a partition column two is installed at the bottom of the open side. An avoidance groove is provided on the surface of the guide slope, and the top of the partition column two passes through the avoidance groove.

[0013] Preferably, one end of the side seat is externally connected to a servo motor three, and inside the side seat there are two gears one and two gears two. The positions of the two gears one are staggered, so that the output end of the servo motor three drives the gears two to rotate.

[0014] Preferably, gear two meshes with gear one, one of gear one is fixedly connected to a movable shaft that rotates around the center of gear two, and the other gear one is fixedly connected to a fixed shaft.

[0015] Preferably, an adjustment handle is provided on one side of the movable shaft, and a positioning shaft is installed between the two inner walls of the side seat, so that the position of the movable shaft can be controlled by adjusting the handle.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. In this invention, the water temperature can be adjusted by an electric heater inside the water tank, and the cooling water tank forms a water circulation through a drain pipe and a water supply pipe. The water pump adjusts the water supply to control the cooling speed. An online infrared spectrometer detects the degree of crystallization in real time, and the constant temperature value and cooling speed are adjusted in combination with the detection results to precisely control the PLA molecular chain arrangement, avoid the straw being too soft or too hard due to crystallization imbalance, and ensure stable molding quality.

[0018] 2. In this invention, the segmented conveying mechanism uses a guide slope, guide groove, and cam driven by a servo motor to convey the cut straws one by one to the sorting mechanism. The conical roller of the sorting mechanism sorts the straws according to their hardness. The recycling bin and weighing equipment in the compartment of the recycling mechanism count the mass percentage and feed the data back to the preceding process to achieve closed-loop regulation of "waste recycling - melting and reprocessing - quality inspection - finished product sorting", thereby improving production efficiency and resource utilization.

[0019] 3. In this invention, the sorting mechanism can flexibly adjust the gap between the conical rollers on the fixed shaft and the movable shaft by adjusting the handle, positioning shaft, gear one and gear two, to adapt to the sorting requirements of suction tubes of different diameters; the partition column one and partition column two of the segmented conveying mechanism ensure the orderly conveying of suction tubes and improve the adaptability of the equipment to different production scenarios. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of a temperature-controlled and speed-controlled crystallizer for forming PLA straws for waste recycling according to the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of a crystallizer for a constant temperature and speed controlled cooling crystallization mechanism for forming PLA straws for waste recycling according to the present invention.

[0022] Figure 3 This is a schematic diagram of the segmented conveying mechanism in a constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling according to the present invention.

[0023] Figure 4 This is a flowchart illustrating the segmented conveying process of a temperature-controlled and speed-regulated crystallizer for forming PLA straws for waste recycling, according to the present invention.

[0024] Figure 5 This is a schematic diagram of the sorting mechanism in a constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling according to the present invention.

[0025] Figure 6 This is a top view of the sorting mechanism in a constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling according to the present invention.

[0026] Figure 7 This is a schematic diagram of the planar structure of the recycling mechanism in a constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling according to the present invention.

[0027] Figure 8 This is a schematic diagram of the side wall planar structure of the side seat in a constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling according to the present invention.

[0028] Figure 9 This is a top view schematic diagram illustrating the principle of a temperature-controlled and speed-regulated crystallizer for forming PLA straws for waste recycling according to the present invention.

[0029] Figure 10 This is a simplified head-up view of the principle of a constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling according to the present invention.

[0030] Figure 11 This is a flowchart of a temperature-controlled and speed-regulated crystallizer sorting process for forming PLA straws for waste recycling, according to the present invention.

[0031] In the diagram: 1. Plasticizing device; 2. Plastic extrusion device; 3. Cooling and crystallizing mechanism; 31. Water tank; 32. Guide roller; 33. Divider; 34. Traction roller; 35. Servo motor one; 4. Cooling water tank; 41. Drainage pipe; 42. Water supply pipe; 5. Segmented conveying mechanism; 51. Guide slope; 52. Guide groove; 53. Rotating seat; 54. Clearance groove; 55. Divider column one; 56. Divider column two; 57. Cam; 58. Servo motor two; 6. Sorting mechanism; 61. Side seat; 611. Movable groove; 612. Positioning screw; 62. Servo motor three; 63. Conical roller; 64. Fixed shaft; 65. Movable shaft; 66. Positioning shaft; 67. Adjusting handle; 68. Gear one; 69. Gear two; 7. Recycling mechanism; 71. Recycling box; 72. Divider plate; 73. Movable window. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1: Refer to Figure 1-11As shown: Before the straw is formed, recycled raw material granules are heated and sheared into PLA molten material by plasticizing device 1. The PLA molten material is then extruded into a tubular structure by plastic extrusion device 2 and discharged from the die outlet of plastic extrusion device 2. The straw is not crystallized and shaped immediately after extrusion. In plasticizing device 1, PLA granules enter the barrel of the device through the feeding system; the heating device outside the barrel (such as an electric heating coil) raises the temperature inside the barrel through heat conduction. When the temperature reaches the melting point of PLA (about 150-170℃), the granules begin to soften and gradually melt; at the same time, the material... The high-speed rotation of the screw inside the barrel generates strong shearing and extrusion forces on the material, which not only accelerates the melting process of the particles but also further breaks down and mixes the incompletely melted particles, making the composition and temperature of the melt more uniform. Finally, the fully plasticized PLA melt is continuously and stably output in a fluid state under the push of the screw for use in subsequent molding processes. In the plastic extrusion device 2, the melt enters the mold cavity under pressure and flows in the annular gap between the inner and outer molds to form a tubular preform. Subsequently, the tubular preform is continuously pushed out of the mold and cooled and shaped by the crystallizer.

[0034] A temperature-controlled and speed-controlled crystallizer for forming PLA straws for waste recycling includes a cooling and crystallization mechanism 3, a segmented conveying mechanism 5, and a sorting mechanism 6. The cooling and crystallization mechanism 3 includes a water tank 31, with the tail end of the water tank 31 being higher than the head end. The head end of the water tank 31 is aligned with the die outlet of the plastic extrusion device 2. Several guide rollers 32 are provided on the upper surface of the water tank 31. The straws are continuously extruded from the die outlet. The guide rollers 32 are used to guide the continuous straws forward. A traction roller 34 is provided at the tail end of the water tank 31, and a corresponding servo motor 35 is provided on the outer side of the tail end. The servo motor 35 drives the traction roller 34 to actively pull the straws to move, thereby guiding the continuous straws. An instrument for measuring the degree of straw crystallization—an online infrared spectrometer—is also provided at the end of the tail end of the water tank 31. The online infrared spectrometer is used to provide feedback on the forming effect of the straws passing through the water tank 31.

[0035] Electric heaters are installed on the two inner walls of the water tank 31, and a cooling water tank 4 is installed on the outside of the cooling crystallization mechanism 3. The surface of the cooling water tank 4 is connected to a drain pipe 41 and a water supply pipe 42. The drain pipe 41 is connected to the bottom wall of the first end of the water tank 31, and the opening of the water supply pipe 42 is installed above the tail end of the water tank 31. A water pump is installed at the end of the water supply pipe 42 to provide water supply power. The output power of the water pump can be intelligently adjusted in different gears to control the water supply flow rate of the water supply pipe 42. Cooling fins are added to the outer surface of the cooling water tank 4 so that the water flowing back into the cooling water tank 4 can dissipate heat in time and maintain a relatively constant temperature. Water falls into the water tank 31 from the water supply pipe 42 and flows from the tail end to the first end of the water tank 31. A dike 33 is installed at the higher end of the water tank 31 to prevent water from overflowing. The suction pipe pulls water from the first end to the tail end of the water tank 31. See the attached diagram for details. Figure 8 and attached Figure 9 The diagram shows that solid corner markers indicate the direction of flow of the straw, while hollow corner markers indicate the direction of water flow.

[0036] After the straw is cooled and crystallized in the water tank 31, it forms a relatively stable solid form. A cutting device is connected to the end of the water tank 31 to cut the continuous straw into a length suitable for commercial use. A sorting mechanism 6 is installed at the end of the water tank 31 to sort the straws that meet the quality requirements. A segmented conveying mechanism 5 is set between the cooling and crystallization mechanism 3 and the sorting mechanism 6. The segmented conveying mechanism 5 is used to transport the cut straws to the sorting mechanism 6 one by one at fixed time intervals.

[0037] The sorting mechanism 6 includes two side seats 61, with a fixed shaft 64 and a movable shaft 65 rotatably connected between them. A movable groove 611 is formed on the upper surface of the side seat 61. A positioning screw 612 is movably connected to the outer wall of the movable shaft 65. The movable shaft 65 is positioned by tightening the positioning screw 612 on the movable groove 611. Conical rollers 63 are installed on the outer walls of both the fixed shaft 64 and the movable shaft 65. The conical rollers 63 have a conical structure that is thicker at one end and thinner at the other. The fixed shaft 64 and the movable shaft 65 always remain parallel, and the gap between the two conical rollers 63 changes from narrow to wide.

[0038] Below the sorting mechanism 6, a recycling mechanism 7 is set up. The recycling mechanism 7 includes a recycling box 71. The recycling box 71 has two partition plates 72 inside. When straws of different hardness pass through the conical roller 63, they fall from different gap widths. The straw's center of gravity falls into the corresponding compartment of the recycling box 71 depending on which side of the partition plate 72 it falls into. The recycling box 71 is divided into three compartments by the two partition plates 72. The middle compartment is for storing straws of moderate hardness. One side compartment stores straws that are too hard, and the other side compartment stores straws that are too soft. Weighing equipment is installed at the bottom of the compartment to count the proportion of qualified straws so as to provide feedback for adjusting various parameters in straw forming (cooling crystallization temperature, cooling crystallization rate, shear force during extrusion, and melting temperature during extrusion). The side wall of the recycling box 71 has movable windows 73 at the positions of the three compartments. After opening the movable windows 73, the straws inside can be taken out at will. Qualified straws are packaged and stored, and unqualified straws are recycled and processed.

[0039] Example 2: According to Figure 1 , Figure 3 and Figure 4 As shown, the segmented conveying mechanism 5 includes a guide slope 51 and a guide groove 52. Both the guide slope 51 and the guide groove 52 are placed at an incline, allowing the suction tube to fall from the guide groove 52 into the guide slope 51 and then roll down the guide slope 51. A servo motor 58 is installed below the bottom of the guide slope 51, and a cam 57 is installed at the output end of the servo motor 58. A rotating seat 53 is rotatably connected to the outer wall of the guide slope 51. The rotating seat 53 is a semi-enclosed structure with three sides closed. A partition column 55 is installed at the top of the open side, and a partition column 56 is installed at the bottom of the open side. An avoidance groove 54 is opened on the surface of the guide slope 51, and the partition column 56... The top of the cam 57 passes through the clearance groove 54 and its surface contacts the lower surface of the rotating seat 53. When the distal point of the cam 57 contacts the rotating seat 53, the cam 57 pushes the rotating seat 53 upward. The second partition post 56 protrudes from the surface of the guide slope 51 and prevents the suction tube from rolling down. When the proximal point of the cam 57 contacts the rotating seat 53, the rotating seat 53 presses down, and the first partition post 55 latches onto the upper surface of the guide slope 51 to prevent the suction tube from rolling down. Each time the second servo motor 58 drives the cam 57 to rotate one revolution, the first partition post 55 and the second partition post 56 oscillate up and down once, inserting a suction tube between the first partition post 55 and the second partition post 56, thus achieving the effect of the suction tube rolling down one by one.

[0040] Example 3: According to Figure 1 , Figure 5 , Figure 6 and Figure 11As shown, when the suction tube falls onto the sorting mechanism 6 for sorting, two conical rollers 63 need to rotate towards each other to squeeze the suction tube in the middle, causing the suction tube to deform under the pressure from both ends, thus facilitating the sorting function. A servo motor 62 is externally connected to one end of the side seat 61. Inside the side seat 61, there are two meshing gears 68 and 69. The output end of the servo motor 62 drives the gear 69 to rotate, causing the two gears 69 to rotate towards each other. The positions of the axes of the two gears 69 remain fixed. The two gears 69 drive the gears 68 to rotate towards each other. One gear 68 rotates around the outer periphery of the gear 69. The center of the gear 68 is fixedly connected to the movable shaft 65. The other gear 68 is in a fixed position. A fixed shaft 64 is fixedly connected to the center of the movable shaft 65, and it remains engaged during rotation to adjust the gap between the two gears 68. An adjustment handle 67 is provided on one side of the movable shaft 65. The adjustment handle 67 includes a threaded seat, a rotating seat, and a screw. The screw is threaded to the threaded seat and rotatably connected to the rotating seat. A positioning shaft 66 is installed between the two inner walls of the side seat 61. The outer wall of the positioning shaft 66 is rotatably connected to the threaded seat of the adjustment handle 67, and the outer wall of the movable shaft 65 is rotatably connected to the rotating seat of the adjustment handle 67. The position of the movable shaft 65 is controlled by adjusting the screw of the adjustment handle 67, so that it rotates around the axis of the meshing gear 69, thereby adjusting the gap between the two conical rollers 63 to adapt to the sorting operation of suction tubes of different diameters.

[0041] Example 4: The softness or hardness of a PLA straw is essentially a direct reflection of the material's crystallinity and molecular chain arrangement. An imbalance between the cooling temperature and crystallization rate in the water will directly cause the straw to be either too soft or too hard—too high a temperature will inhibit crystallization, making the straw softer due to the loose molecular chains; too low a temperature or too fast crystallization will result in excessive crystallization, leading to increased brittleness and a harder feel.

[0042] When the water temperature is too high, the molecular chains retain a certain degree of fluidity, making crystallization difficult and resulting in low crystallinity in the straw. In this case, the internal molecular arrangement is loose, and the structural support is insufficient, causing the straw to feel soft and even easily deformed and not heat-resistant. Furthermore, if the crystallization rate is too slow during cooling, the PLA molecular chains have enough time to arrange themselves disorderedly, resulting in low crystallinity. In this situation, although the straw has good toughness, it lacks rigidity, appearing "soft," and may bend or collapse under stress.

[0043] When the water temperature is below the crystallization temperature range of PLA, the molecular chains are suddenly "frozen," forcing the crystallization process to complete rapidly. This easily leads to the formation of small, dense crystals, resulting in excessive crystallinity. At this point, the material's rigidity increases, but its toughness decreases, causing the straw to become "harder" due to increased brittleness and even break easily. Furthermore, if the cooling rate is too rapid, the crystallization process lacks sufficient time for the molecular chains to align properly, potentially forming an uneven crystal structure with locally excessive crystallinity. This structural imbalance makes the straw feel stiff overall and prone to cracking when bent.

[0044] An online infrared spectrometer is installed at the tail end of the water tank 31 to detect the degree of crystallization of the suction tube pulled by the traction roller 34. If the degree of crystallization is higher than the crystallization value of the standard suction tube, the temperature during the cooling process is too low and the cooling rate is too fast. At this time, it is necessary to adjust the temperature of the electric heater installed on the inner wall of the water tank 31 to raise the temperature of the electric heater and maintain a constant cooling temperature. Since the speed of the plastic extrusion device 2 extruding the suction tube is a constant value, in order to avoid the suction tube being torn due to excessive tension, the extrusion speed of the suction tube is matched with the traction speed of the traction roller 34. One of the factors of the cooling speed of the suction tube is the relative flow velocity of the water flowing through the suction tube. The movement speed of the suction tube body remains unchanged. The water pump is adjusted to control the flow rate of the water supply pipe 42 to control its flow velocity in the water tank 31, thereby achieving the effect of increasing or delaying the crystallization speed. In summary, the molding quality of the suction tube can be controlled by adjusting the constant temperature value and the cooling speed.

[0045] Three compartments are set up inside the recycling bin 71, and weighing equipment is installed in each compartment to count the proportion of qualified and unqualified straws. The statistical data is used to adjust the parameters of the straw recycling process. If there are too many soft straws in the compartment, it indicates that the temperature of the recycled waste is too high during melting, even with constant temperature and speed control for straw cooling. This causes PLA molecular chains to degrade and break, reducing the molecular weight and decreasing the crystallization ability of low molecular weight materials during subsequent cooling. If there are too few soft straws in the compartment, the temperature of the recycled waste is too low during melting, resulting in insufficient melting, impurities, and uneven crystallization during cooling. Adjusting the straw quality can also adjust other parameters such as screw speed and particle size uniformity. This feedback adjustment of the preceding recycling process forms a closed-loop process of "waste recycling - melting and reprocessing - straw quality inspection - finished straw sorting".

[0046] The operating method and working principle of this device are as follows: The plasticizing device 1 heats and shears the recycled raw materials into PLA molten material, which is then extruded into a tubular structure by the plastic extrusion device 2 and enters the water tank 31 of the cooling crystallization mechanism 3. The first end of the water tank 31 is aligned with the die outlet, guided by the guide roller 32, and the servo motor 35 drives the traction roller 34 to move the suction tube. The electric heater inside the water tank 31 works in conjunction with the cooling water tank 4, and water circulation is achieved through the drain pipe 41 and the water supply pipe 42. The water pump adjusts the water supply to control the cooling speed, and the heat dissipation fins of the cooling water tank 4 maintain a stable water temperature. The degree of crystallization is detected by an online infrared spectrometer. The cut suction tube... The cam 57, driven by the second servo motor 58, drives the first partition column 55 and the second partition column 56 of the rotating seat 53 to transport the materials one by one to the sorting mechanism 6 via the guide slope 51 and guide groove 52 of the segmented conveying mechanism 5. In the sorting mechanism 6, the third servo motor 62 drives the first gear 68 and the second gear 69 to rotate the conical roller 63 of the fixed shaft 64 and the movable shaft 65. The adjustment handle 67 and the positioning shaft 66 adjust the gap, and different soft and hard suction tubes fall from the corresponding gap into the recycling box 71 of the recycling mechanism 7. They are then divided into three compartments by the separator 72, the weighing equipment counts the proportion, the movable window 73 picks up the materials, and the data feedback adjusts the parameters to form a closed loop of the process.

[0047] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A temperature-controlled and speed-regulated crystallizer for forming PLA straws for waste recycling, comprising a cooling crystallization mechanism (3), a segmented conveying mechanism (5), and a sorting mechanism (6), characterized in that: The cooling crystallization mechanism (3) includes a water tank (31). The inner cavity of the water tank (31) is inclined from the tail end to the head end. The head end of the water tank (31) is aligned with the die outlet of the plastic extrusion device (2). Several guide rollers (32) are provided on the upper surface of the water tank (31). A traction roller (34) is provided at the tail end of the water tank (31). A servo motor (35) is provided on the outer wall of the water tank (31). The servo motor (35) drives the traction roller (34) to pull the suction tube to move. Electric heaters are provided on the two inner walls of the water tank (31), and a cooling water tank (4) is provided on the outer side of the cooling crystallization mechanism (3). A drain pipe (41) and a water supply pipe (42) are connected to the surface of the cooling water tank (4). The drain pipe (41) is connected to the bottom wall at the head end of the water tank (31), and the opening of the water supply pipe (42) is set above the tail end of the water tank (31). A water pump is provided at the other end of the water supply pipe (42), and a partition dike (33) is provided inside the tail end of the water tank (31). The sorting mechanism (6) is installed at the tail end of the water tank (31). The segmented conveying mechanism (5) is located between the cooling crystallization mechanism (3) and the sorting mechanism (6). The segmented conveying mechanism (5) is used to convey the cut-off suction tubes one by one to the sorting mechanism (6). The sorting mechanism (6) includes two side seats (61). A fixed shaft (64) and a movable shaft (65) are rotatably connected between the two side seats (61). A movable groove (611) is provided on the upper surface of the side seat (61). A positioning screw (612) is movably connected to the outer side wall of the movable shaft (65). A conical roller (63) is installed on the outer side wall of both the fixed shaft (64) and the movable shaft (65). The fixed shaft (64) and the movable shaft (65) always remain parallel. The gap between the two conical rollers (63) changes from narrow to wide.

2. The constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling according to claim 1, characterized in that: Below the sorting mechanism (6) is a recycling mechanism (7), which includes a recycling box (71). The recycling box (71) has two partitions (72) inside. The bottom of the recycling box (71) is equipped with a weighing device. The side wall of the recycling box (71) has movable windows (73) at three compartment positions.

3. The constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling according to claim 1, characterized in that: The segmented conveying mechanism (5) includes a guide slope (51) and a guide groove (52). Both the guide slope (51) and the guide groove (52) are placed in an inclined state. The suction tube falls from the guide groove (52) into the guide slope (51) and then rolls down from the guide slope (51).

4. The constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling according to claim 3, characterized in that: A servo motor (58) is provided below the bottom of the guide slope (51). A cam (57) is installed at the output end of the servo motor (58). A rotating seat (53) is rotatably connected to the outer wall of the guide slope (51). The surface of the cam (57) is in contact with the lower surface of the rotating seat (53).

5. A temperature-controlled and speed-regulated crystallizer for forming PLA straws for waste recycling according to claim 4, characterized in that: The rotating seat (53) is a semi-enclosed structure with three sides closed, and a partition column one (55) is installed at the top of the open side, and a partition column two (56) is installed at the bottom of the open side. A clearance groove (54) is provided on the surface of the guide slope (51), and the top of the partition column two (56) passes through the clearance groove (54).

6. The constant temperature and speed controlled crystallizer for forming PLA straws for waste recycling according to claim 1, characterized in that: One end of the side seat (61) is connected to a servo motor three (62). Inside the side seat (61) are two gears one (68) and two gears two (69). The positions of the two gears one (68) are staggered, so that the output end of the servo motor three (62) drives the gears two (69) to rotate.

7. A temperature-controlled and speed-regulated crystallizer for forming PLA straws for waste recycling according to claim 6, characterized in that: The second gear (69) meshes with the first gear (68), one of the first gears (68) is fixedly connected to a movable shaft (65), the movable shaft (65) rotates around the center of the second gear (69), and the other gear (68) is fixedly connected to a fixed shaft (64).

8. A temperature-controlled and speed-regulated crystallizer for forming PLA straws for waste recycling according to claim 1, characterized in that: An adjustment handle (67) is provided on one side of the movable shaft (65), and a positioning shaft (66) is installed between the two inner walls of the side seat (61). The position of the movable shaft (65) is controlled by adjusting the handle (67).

Images