Pure PLA fabric, production equipment and process

Abstract

The invention provides a pure PLA fabric, production equipment and a process, and relates to the technical field of chemical fiber production. The pure PLA fabric production equipment comprises polymerization equipment, a discharge pump, a granulator, spinning equipment, fiber processing equipment, negative pressure equipment, protective gas supply equipment and weaving equipment. According to the invention, the organic guanidine catalyst, the D-lactide and the L-lactide are stirred and uniformly mixed by the stirrer and then form a continuous fluid on the reaction tank through the nozzle in the spray head, the continuous fluid flows through the dead weight of the fluid and then forms a film shape, and the film-shaped fluid can accelerate the separation of internal water vapor in the reaction process, so that the reaction efficiency is improved. The dip angle of the reaction tank can be controlled by driving the cam to rotate through the first motor, so that the flowing speed of fluid on the reaction tank can be conveniently controlled, the reaction time can be accurately controlled, and when a mixture is sprayed out through the spray head, multiple cutting and mixing actions are formed through the metal net, so that the dispersion degree of a catalyst is further improved; and the condition of catalyst agglomeration is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical fiber production, and in particular to pure PLA fabric, production equipment and process. Background Art

[0002] PLA is a polymer material with good development prospects. It is not only biodegradable and biocompatible, but can also be produced and processed using most general processing equipment. The preparation methods of polylactic acid include: polycondensation, chain extension, and lactide ring-opening polymerization.

[0003] The preparation method currently used in industrial production is in contact with air during the production process, and the contact time is long, which causes oxidation of the raw materials, resulting in a low yield of the final polymerization product. The larger polymerization reactor makes the raw materials react unevenly, affecting the low-consumption and high-output industrial production. For this reason, there is a public technology on the market that proposes a continuous polymerization process for producing polylactic acid chips from lactide, comprising the following steps: lactide in the lactide workshop and the devolatilization reactor enters the lactide buffer tank through a lactide pipeline; a part of the lactide is circulated to the lactide buffer tank, and the other part of the lactide enters the lactide preheater; the lactide and three catalysts enter the static mixer for thorough mixing; after the mixing is completed, the mixture enters the lactide prepolymerization reactor for ring-opening polymerization; the mixture is transported to the lactide polymerization system for polymerization reaction to generate a melt; a part of the melt output from the polymerization system is circulated to the tubular reactor, and the other part is transported to the devolatilization reactor for devolatilization; after the devolatilization is completed, the melt is mixed with the modifying additive and transported to the granulation system by the devolatilization discharge pump, and the polymerization process is completed. In this technology, multiple devices are in a closed system and protected by high-purity nitrogen. The entire production process will not come into contact with air, and polylactic acid will not be oxidized or degraded. However, the above-mentioned improved technology still uses the common kettle reactor on the market, which makes it difficult to remove water molecules from the high-viscosity polymer mixture. The PLA polymer obtained by this method has only a low molecular weight, which still causes the subsequent PLA fibers and fabrics to be hard and brittle, lacking elasticity and toughness. These characteristics limit the application scope of PLA fibers in the textile field, and further improvements are necessary. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a pure PLA fabric, production equipment and process, which solves the problem of mixture accumulation during the polymerization process in the existing pure PLA fabric, production equipment and process, which makes it difficult to remove water and leads to a low molecular weight of the final product.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A production device for pure PLA fabric, including a polymerization device, a discharge pump, a granulator, a spinning device, a fiber processing device, a negative pressure device, a protective gas supply device, and a weaving device. The polymerization device includes a reaction tank and a control system. The reaction tank is supported by a support frame. Two groups of raw material storage tanks are fixedly connected to the top of the reaction tank. A catalyst storage tank is fixedly connected to the upper wall of the reaction tank on one side of the two groups of raw material storage tanks. A receiving hopper is fixedly connected to the lower wall of the reaction tank inside the support frame. The lower end of the receiving hopper is provided with a discharge port. A partition is fixedly connected to the inner side wall of the reaction tank. The interior of the reaction tank is divided into a feed chamber and a reaction chamber that are distributed vertically by the partition. Three groups of screw extruders are fixedly connected to the upper wall of the partition in a front-back distribution. The inlet ends of the three groups of screw extruders are respectively connected to the catalyst storage tank and the two groups of raw material storage tanks. The outlet ends of the three groups of screw extruders are all fixedly connected to conveying pipes. The ends of the three conveying pipes away from the screw extruders are jointly fixedly connected to a stirrer through a joint. The outlet end of the stirrer is fixedly connected to a connecting pipe. The end of the connecting pipe away from the stirrer penetrates the inner wall of the partition and extends to the lower side of the partition. Inside the reaction tank and below the partition, a reaction tank for raw material reaction is rotatably connected through a first rotating shaft.

[0006] Preferably, filters are fixedly connected to the outer walls of the three groups of conveying pipes. A stirring structure for stirring and mixing is provided inside the stirrer. A U-shaped frame is provided on the side of the reaction tank away from the first rotating shaft. On the side of the U-shaped frame away from the reaction tank and near the upper end, sliding rods are fixedly connected through two groups of first fixing seats. A sliding block is slidably connected to the outer wall of the sliding rod. A translation driving structure for driving the sliding block to move back and forth is provided on the first fixing seat. A spraying structure for spraying the mixed raw materials onto the left wall of the reaction tank to form a continuous film is provided on the sliding block. The end of the connecting pipe extending to the lower side of the partition is connected to the spraying structure through a hose. An inclination adjustment structure for adjusting the angle between the reaction tank and the horizontal plane is provided inside the reaction tank. A temperature increase structure for heating to dehydrate is provided on the reaction tank. A temperature detection structure for detecting the reaction temperature is provided on the side of the U-shaped frame away from the reaction tank and below the first fixing seat. A negative pressure pipe and a protective gas inlet pipe are fixedly connected to the left wall of the reaction tank in a vertical distribution. Both the negative pressure pipe and the protective gas inlet pipe are connected to the reaction chamber. The ends of the negative pressure pipe and the protective gas inlet pipe away from the reaction tank are respectively connected to the negative pressure device and the protective gas supply device. Heat dissipation windows for facilitating heat dissipation are provided on the front wall and the rear wall of the feed chamber.

[0007] Preferably, the stirring structure includes a second motor, a stirring shaft, and a screw blade. The second motor is fixedly connected to the left end of the stirrer. The extending shaft of the second motor penetrates through the left wall of the stirrer and extends into the interior of the stirrer. The stirring shaft is fixedly connected to the end of the extending shaft of the second motor. The screw blade is fixedly connected to the outer wall of the stirring shaft.

[0008] Preferably, the translation driving structure includes a third motor and a threaded rod. The third motor is fixedly connected to the front wall of the front set of the two first fixing seats. The extending shaft of the third motor penetrates through the inner wall of the first fixing seat and extends between the two first fixing seats. The threaded rod is fixedly connected to the end of the extending shaft of the third motor. The outer wall of the threaded rod penetrates through the inner wall of the sliding block and is threadedly connected thereto. The end of the threaded rod away from the third motor is rotatably connected to the front wall of the rear set of the two first fixing seats.

[0009] Preferably, the spraying structure includes a spray head and a metal mesh. The spray head is fixedly connected to the left wall of the sliding block. A spray nozzle is provided at one end of the spray head facing the reaction tank. The spray nozzle is strip-shaped. The metal mesh is fixedly connected to the inner side wall of the spray head.

[0010] Preferably, the inclination angle adjusting structure includes a first motor, a second rotating shaft, and a cam. The first motor is fixedly connected to the front wall of the reaction tank. The end of the extending shaft of the first motor penetrates through the front wall of the reaction tank and extends into the interior of the reaction chamber. The second rotating shaft is fixedly connected to the end of the extending shaft of the first motor. The end of the second rotating shaft away from the first motor is rotatably connected to the inner rear wall of the reaction chamber. The cam is fixedly connected to the outer wall of the second rotating shaft. The outer circumferential wall of the cam is in sliding contact with the right wall of the reaction tank.

[0011] Preferably, the heating-up structure includes multiple groups of heat conducting plates and electric heating rods. The multiple groups of heat conducting plates are all vertically distributed and fixedly connected to one side of the reaction tank away from the first rotating shaft in sequence. The distance between any two adjacent groups of the multiple groups of heat conducting plates is equal. The left walls of the multiple groups of heat conducting plates are flush with the left wall of the reaction tank. The multiple groups of electric heating rods are respectively fixedly connected to the inner side wall of one group of heat conducting plates.

[0012] Preferably, the temperature detection structure includes multiple groups of temperature sensors. Multiple groups of second fixing seats are fixedly connected in sequence in a vertical distribution on the side of the U-shaped frame away from the reaction tank and below the first fixing seat. A fixing rod is fixedly connected between two sets of the multiple groups of second fixing seats that are corresponding front and rear. The multiple groups of temperature sensors are respectively fixedly connected to the outer wall of one group of fixing rods. The detection ends of the temperature sensors face the left wall of the reaction tank.

[0013] A production process of a pure PLA fabric is carried out using any one of the above-mentioned pure PLA fabric production equipment. The production process includes the following steps: S1. Prepare materials: prepare a catalyst, a first raw material, and a second raw material, add the catalyst to a catalyst storage tank, and add the first raw material and the second raw material to a set of raw material storage tanks respectively, wherein the catalyst is an organic guanidine catalyst, the first raw material is D-lactide, and the second raw material is L-lactide; S2, polymerization, the catalyst, the first raw material and the second raw material are extruded and fed respectively through a set of screw extruders, and are conveyed into the interior of the stirrer together. During the conveying, they are fully filtered through a filter. The second motor on the stirrer drives the stirring shaft to rotate, which in turn drives the auger blades to rotate, and the catalyst, the first raw material and the second raw material entering the stirrer are fully stirred to form a mixture and conveyed to the rear end; S3, open-loop reaction, the mixture enters the nozzle through the connecting pipe and the hose, and is sprayed toward the left wall of the reaction tank through the nozzle on the nozzle. During the spraying process, the third motor drives the threaded rod to rotate, and the threaded rod drives the sliding block to move axially along the sliding rod through the threaded connection relationship between the threaded rod and the sliding block. By changing the rotation direction of the third motor, the sliding block moves back and forth, and then a continuous mixture is sprayed on the left wall of the reaction tank through the nozzle. During the spraying process, the mixture is mixed again when passing through the metal mesh. Before spraying, the cam is driven to rotate by the first motor to adjust the angle between the left wall of the reaction tank and the horizontal plane. A large angle can increase the downward movement of the mixture sprayed on the reaction tank. On the contrary, a small angle can slow down the downward flow speed of the mixture. Due to the characteristic that the mixture flows downward along the left wall of the reaction tank, the mixture forms a thin film on the left wall of the reaction tank. In this process, the polymer film is heated in a step-by-step temperature control manner through multiple sets of temperature sensors, heat conducting plates and multiple sets of electric heating rods, which is convenient for degassing and dehydration of the mixture. At the same time, the gas and water vapor in the reaction chamber are extracted through the negative pressure pipe by the negative pressure equipment, and the protective gas is fed into the protective gas inlet pipe. The mixture after the reaction forms a polylactic acid fluid, which flows into the receiving hopper by its own weight, and is extracted by the discharge pump through the discharge port and then fed into the granulation equipment for cooling and granulation to form PLA particles. S4. The PLA pellets are melt-spun through a spinning device to form PLA fiber filaments, the PLA fiber filaments are heat-set through a fiber processing device, and then woven into pure PLA fabrics through a weaving device.

[0014] According to the above-mentioned pure PLA fabric, the pure PLA fabric is produced by adopting the above-mentioned production process of pure PLA fabric.

[0015] The present invention provides a pure PLA fabric, production equipment and process. It has the following beneficial effects: 1. Compared with existing technologies, this pure PLA fabric, production equipment, and process utilize an organic guanidine catalyst, D-lactide, and L-lactide to mix thoroughly in a stirrer before flowing through a nozzle in a nozzle to form a continuous fluid on a reaction tank. The fluid flows under its own gravity to form a thin film. During the reaction process, the thin film fluid can accelerate the separation of internal water vapor, achieving the purpose of purification, thereby obtaining high-molecular-weight PLA and greatly improving the mechanical properties of the PLA fabric.

[0016] 2. Compared with the existing technology, this pure PLA fabric, production equipment and process can control the inclination angle of the reaction tank by rotating the cam driven by the first motor, so as to facilitate the control of the flow speed of the fluid in the reaction tank, and thus accurately control the reaction time.

[0017] 3. Compared with the existing technology, the pure PLA fabric, production equipment and process, when the mixture is sprayed out through the nozzle, it forms multiple cutting and mixing actions through the metal mesh, which further improves the dispersion of the catalyst and avoids the agglomeration of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 This is a top cross-sectional view of the internal structure of the feed chamber in the reaction box of the present invention; Figure 3 A partial cross-sectional view of the connection structure of the agitator, the second motor, the agitator shaft, and the auger blades of the present invention; Figure 4 It is a partial cross-sectional view of the internal structure of the reaction box of the present invention; Figure 5 For the present invention Figure 4 A partial enlarged view of point A in the middle; Figure 6 This is a schematic diagram of the connection structure of the reaction tank and the heat conducting plate of the present invention; Figure 7 It is a partial cross-sectional view of the reaction tank, the first fixing seat, the sliding rod, the threaded rod, the sliding block and the third motor connection structure of the present invention; Figure 8 This is a schematic diagram of the connection structure of the second fixing base, the fixing rod and the temperature sensor of the present invention; Figure 9 Schematic diagram of the cross section of the nozzle of the present invention; Figure 10 It is a schematic diagram of the nozzle structure of the present invention.

[0019] Among them, 1. reaction box; 101. partition; 2. support frame; 3. hopper; 4. discharge port; 5. protective gas inlet pipe; 6. negative pressure pipe; 7. heat dissipation window; 8. catalyst storage tank; 9. raw material storage tank; 10. first motor; 11. screw extruder; 12. conveying pipeline; 13. filter; 14. joint; 15. agitator; 16. second motor; 17. agitator shaft; 18. auger blade; 19. connecting pipe; 20. first rotating shaft; 21. reaction tank; 22. first fixed seat; 23. third motor; 24. second rotating shaft; 25. cam; 26. electric heating rod; 27. second fixed seat; 28. fixed rod; 29. ​​temperature sensor; 30. heat conduction plate; 31. threaded rod; 32. sliding rod; 33. sliding block; 34. nozzle; 3401. nozzle; 35. metal mesh. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] Example: like Figures 1 to 10As shown, an embodiment of the present invention provides a production equipment for pure PLA fabrics, including polymerization equipment, a discharge pump, a granulator, a spinning equipment, a fiber processing equipment, a negative pressure equipment, a protective gas providing equipment and a weaving equipment. The polymerization equipment includes a reaction box 1 and a control system. The reaction box 1 is supported by a support frame 2. Two groups of raw material storage tanks 9 are fixedly connected to the top of the reaction box 1. A catalyst storage tank 8 is fixedly connected to the upper wall of the reaction box 1 and located on one side of the two groups of raw material storage tanks 9. A hopper 3 is fixedly connected to the lower wall of the reaction box 1 and located inside the support frame 2. A discharge port 4 is provided at the lower end of the hopper 3. A partition 101 is fixedly connected to the inner side wall of the reaction box 1. The interior of the reaction box 1 is divided into a feed chamber and a reaction chamber distributed in an upper and lower manner by the partition 101. Three groups of screw extruders 11 are fixedly connected to the upper wall of the partition 101 in a front-to-back distribution. The inlet ends of the three groups of screw extruders 11 are respectively connected to the catalyst storage tank 8 and the two groups of raw material storage tanks 9. , the outlet ends of the three groups of screw extruders 11 are fixedly connected to the conveying pipes 12, and the ends of the three groups of conveying pipes 12 away from the screw extruders 11 are fixedly connected to the agitator 15 through a group of joints 14, and the outlet end of the agitator 15 is fixedly connected to the connecting pipe 19, and the end of the connecting pipe 19 away from the agitator 15 passes through the inner wall of the partition 101 and extends to the lower side of the partition 101. Inside the reaction box 1 and below the partition 101, it is rotatably connected to the reaction tank 21 for raw material reaction through the first rotating shaft 20. The outer walls of the three groups of conveying pipes 12 are fixedly connected to the filters 13. The left wall of the reaction box 1 is distributed up and down and fixedly connected with the negative pressure pipe 6 and the protective gas inlet pipe 5 in sequence. The negative pressure pipe 6 and the protective gas inlet pipe 5 are both connected to the reaction chamber. The ends of the negative pressure pipe 6 and the protective gas inlet pipe 5 away from the reaction box 1 are respectively connected to the negative pressure equipment and the protective gas supply equipment. The front wall and the rear wall of the feed chamber are provided with heat dissipation windows 7 for convenient heat dissipation. In order to fully blend the raw materials and the catalyst, a stirring structure for stirring and mixing is provided inside the agitator 15, and the stirring structure includes a second motor 16, a stirring shaft 17 and an auger blade 18. The second motor 16 is fixedly connected to the left end of the agitator 15, and the second motor 16 extends a shaft that penetrates the left wall of the agitator 15 and extends into the interior of the agitator 15. The stirring shaft 17 is fixedly connected to the end of the shaft extending from the second motor 16, and the auger blade 18 is fixedly connected to the outer wall of the stirring shaft 17. After the raw materials and the catalyst are fed into the agitator 15, the second motor 16 drives the stirring shaft 17 and the auger blade 18 to rotate, driving the mixture to form a spiral flow in the agitator 15. During the spiral flow, the raw materials and the catalyst are fully blended. In order to spray the mixture onto the side wall of the reaction tank 21, a U-shaped frame is provided on the side of the reaction tank 21 away from the first rotating shaft 20. On the side of the U-shaped frame away from the reaction tank 21 and near the upper end, two groups of first fixing seats 22 are fixedly connected to a sliding rod 32. The outer wall of the sliding rod 32 is slidably connected to a sliding block 33. A spraying structure is provided on the sliding block 33 for spraying the mixed raw materials onto the left wall of the reaction tank 21 to form a continuous film. The end of the connecting pipe 19 extending under the partition 101 is connected to the spraying structure through a hose. The spraying structure includes a spray head 34 and a metal mesh 35. The spray head 34 is fixedly connected to the left wall of the sliding block 33. One end of the spray head 34 facing the reaction tank 21 is provided with a spray port 3401. The spray port 3401 is strip-shaped. The metal mesh 35 is fixedly connected to the inner side wall of the spray head 34. The mixture is sent into the spray head 34 through the pumping pressure of the previous process and is sprayed onto the reaction tank 21 through the spray port 3401. The mixture completes the ring-opening polymerization reaction on the reaction tank 21. During the spraying process, when the mixed fluid passes through the metal mesh 35, it is cut and mixed multiple times, further improving the mixing uniformity of the catalyst and the raw materials; In order to complete continuous spraying, a translation driving structure for driving the sliding block 33 to move back and forth is provided on the first fixing seat 22. The translation driving structure includes a third motor 23 and a threaded rod 31. The third motor 23 is fixedly connected to the front wall of the frontmost group of the two groups of first fixing seats 22. The extending shaft of the third motor 23 penetrates through the inner wall of the first fixing seat 22 and extends between the two groups of first fixing seats 22. The threaded rod 31 is fixedly connected to the end of the extending shaft of the third motor 23. The outer wall of the threaded rod 31 penetrates through the inner wall of the sliding block 33 and is threadedly connected thereto. The end of the threaded rod 31 away from the third motor 23 is rotatably connected to the front wall of the rearmost group of the two groups of first fixing seats 22. The third motor 23 drives the threaded rod 31 to rotate. Through the threaded connection relationship between the threaded rod 31 and the sliding block 33, the sliding block 33 can be driven to move. By the continuous forward and reverse rotation actions of the third motor 23, the back-and-forth spraying action of the spray head 34 can be realized. Since the reaction tank 21 is inclined, the sprayed mixture flows downward along the side wall of the reaction tank 21 by its own weight, and then a mixture film is formed on the side wall of the reaction tank 21. The film-like structure is conducive to the rapid removal of gas and moisture in the mixture, greatly improving the dehydration and degassing effect and effectively improving the product quality; In order to adjust the flow rate of the mixed fluid on the reaction tank 21, an inclination angle adjusting structure for adjusting the angle between the reaction tank 21 and the horizontal plane is provided inside the reaction tank 1. The inclination angle adjusting structure includes a first motor 10, a second rotating shaft 24 and a cam 25. The first motor 10 is fixedly connected to the front wall of the reaction tank 1. The end of the extending shaft of the first motor 10 penetrates through the front wall of the reaction tank 1 and extends into the reaction chamber. The second rotating shaft 24 is fixedly connected to the end of the extending shaft of the first motor 10. The end of the second rotating shaft 24 away from the first motor 10 is rotatably connected to the inner rear wall of the reaction chamber. The cam 25 is fixedly connected to the outer wall of the second rotating shaft 24. The outer wall of the circumference of the cam 25 is in sliding contact with the right wall of the reaction tank 21. When the first motor 10 drives the cam 25 to rotate, the inclination angle of the reaction tank 21 can be adjusted. When the reaction tank 21 is close to the vertical horizontal plane, the fluid flow rate is fast, the film thickness is small, and the degassing and dehydration effects are good. When the angle between the reaction tank 21 and the horizontal plane is small, the fluid flow rate is slow, the residence time of the fluid on the reaction tank 21 is long, and the reaction is more sufficient. By combining the different water contents in the raw materials with simple test actions, the optimal inclination angle state of the reaction tank 21 can be easily obtained; [[ID=^]]In order to accurately control the ring-opening polymerization reaction, a temperature-rising structure for heating to dehydrate is provided on the reaction tank 21. A temperature detection structure for detecting the reaction temperature is provided on the side of the C-shaped frame away from the reaction tank 21 and below the first fixing seat 22. The temperature-rising structure includes multiple groups of heat conduction plates 30 and electric heating rods 26. Multiple groups of heat conduction plates 30 are all arranged vertically and fixedly connected to the side of the reaction tank 21 away from the first rotating shaft 20 in sequence. The distance between any two adjacent groups of multiple groups of heat conduction plates 30 is equal. The left walls of multiple groups of heat conduction plates 30 are flush with the left wall of the reaction tank 21. Multiple groups of electric heating rods 26 are respectively fixedly connected to the inner side walls of a group of heat conduction plates 30. The temperature detection structure includes multiple groups of temperature sensors 29. Multiple groups of second fixing seats 27 are fixedly connected in sequence vertically on the side of the C-shaped frame away from the reaction tank 21 and below the first fixing seat 22. A fixing rod 28 is fixedly connected between two groups of the front and rear corresponding groups of multiple groups of second fixing seats 27. Multiple groups of temperature sensors 29 are respectively fixedly connected to the outer walls of a group of fixing rods 28. The detection ends of the temperature sensors 29 face the left wall of the reaction tank 21. The control system collects the temperature information detected by multiple groups of temperature sensors 29 to control the different heating temperatures of multiple groups of electric heating rods 26 according to the actual temperature information, so as to achieve the purpose of gradient temperature control and greatly improve the reaction effect.

[0022] A production process of a pure PLA fabric, which is produced by using the above pure PLA fabric production equipment, is characterized in that the production process includes the following steps: S1. Prepare materials, prepare a catalyst, a first raw material and a second raw material, add the catalyst to the catalyst storage tank 8, and add the first raw material and the second raw material to a group of raw material storage tanks 9 respectively. Among them, the catalyst is an organic guanidine catalyst, the first raw material is D-lactide, and the second raw material is L-lactide; S2, polymerization, the catalyst, the first raw material and the second raw material are extruded and fed respectively through a set of screw extruders 11, and are conveyed together into the interior of the stirrer 15. During the conveying, they are fully filtered through the filter 13. The second motor 16 on the stirrer 15 drives the stirring shaft 17 to rotate, thereby driving the auger blades 18 to rotate, and the catalyst, the first raw material and the second raw material entering the stirrer 15 are fully stirred to form a mixture and conveyed to the rear end; S3, open-loop reaction, the mixture enters the nozzle 34 through the connecting pipe 19 and the hose, and is sprayed toward the left wall of the reaction tank 21 through the nozzle 3401 on the nozzle 34. During the spraying process, the third motor 23 drives the threaded rod 31 to rotate. The threaded rod 31 drives the sliding block 33 to move axially along the sliding rod 32 through the threaded connection relationship between the threaded rod 31 and the sliding block 33. By changing the rotation direction of the third motor 23, the sliding block 33 moves back and forth, and then the continuous mixture is sprayed on the left wall of the reaction tank 21 through the nozzle 34. During the spraying process, the mixture is mixed again when passing through the metal mesh 35. Before spraying, the cam 25 is driven to rotate by the first motor 10 to adjust the angle between the left wall of the reaction tank 21 and the horizontal plane. A large angle can improve the spraying The downward flow speed of the mixture coated on the reaction tank 21 is reduced. Conversely, a small angle can slow down the downward flow speed of the mixture. Due to the characteristic that the mixture flows downward along the left wall of the reaction tank 21, the mixture forms a thin film on the left wall of the reaction tank 21. In this process, the polymer film is heated in a step-by-step temperature control manner by multiple sets of temperature sensors 29, heat conducting plates 30 and multiple sets of electric heating rods 26, which facilitates degassing and dehydration of the mixture. At the same time, the gas and water vapor inside the reaction chamber are extracted through the negative pressure pipe 6 by the negative pressure device, and the protective gas is fed into the protective gas inlet pipe 5. The mixture after the reaction forms a polylactic acid fluid, which flows into the receiving hopper 3 by its own weight, and is extracted by the discharge pump through the discharge port 4 and then fed into the granulation equipment for cooling and granulation to form PLA particles. S4. The PLA pellets are melt-spun through a spinning device to form PLA fiber filaments, the PLA fiber filaments are heat-set through a fiber processing device, and then woven into pure PLA fabrics through a weaving device.

[0023] According to the above-mentioned pure PLA fabric, the pure PLA fabric is produced by adopting the above-mentioned production process of pure PLA fabric.

[0024] Working principle: After the raw materials and catalyst are fed into the agitator 15, the second motor 16 drives the agitator shaft 17 and the auger blade 18 to rotate, driving the mixture to form a spiral flow in the agitator 15. During the spiral flow, the raw materials and the catalyst are fully integrated. The mixture is fed into the nozzle 34 through the pumping pressure of the previous process and sprayed onto the reaction tank 21 through the nozzle 3401. The mixture completes the ring-opening polymerization reaction in the reaction tank 21. During the spraying process, the mixture fluid is cut and mixed many times when passing through the metal mesh 35, which further improves the mixing uniformity of the catalyst and the raw materials. The third motor 23 drives the threaded rod 31 to rotate. The threaded connection between the threaded rod 31 and the sliding block 33 can drive the sliding block 33 to move. The continuous forward and reverse rotation of the third motor 23 can realize the back and forth spraying action of the nozzle 34. Since the reaction tank 21 is set at an angle, the sprayed mixture It flows downward along the side wall of the reaction tank 21 by its own weight, and then forms a mixture film on the side wall of the reaction tank 21. The film-like structure is conducive to the rapid removal of gas and water in the mixture, greatly improving the dehydration and degassing effect, and effectively improving product quality. When the first motor 10 drives the cam 25 to rotate, the inclination angle of the reaction tank 21 can be adjusted. When the reaction tank 21 is close to the vertical horizontal plane, the fluid flow speed is fast, the film thickness is small, and the degassing and dehydration effect is good. When the angle between the reaction tank 21 and the horizontal plane is small, the fluid flow speed is slow, the fluid stays in the reaction tank 21 for a long time, and the reaction is more complete. Through the different water content in the raw materials combined with simple test actions, the optimal inclination state of the reaction tank 21 can be easily obtained. The control system collects temperature information detected by multiple groups of temperature sensors 29 to control the different heating temperatures of multiple groups of electric heating rods 26 according to the actual temperature information to achieve the purpose of gradient temperature control, which greatly improves the reaction effect.

[0025] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A pure PLA fabric production equipment, characterized by: It includes an aggregation device, a discharging pump, a granulator, a spinning device, a fiber processing device, a negative pressure device, a protective gas supply device, and a weaving device. The aggregation device includes a reaction tank (1) and a control system. The reaction tank (1) is supported by a support frame (2). Two groups of raw material storage tanks (9) are fixedly connected to the top of the reaction tank (1). A catalyst storage tank (8) is fixedly connected to the upper wall of the reaction tank (1) and on one side of the two groups of raw material storage tanks (9). A receiving hopper (3) is fixedly connected to the lower wall of the reaction tank (1) and inside the support frame (2). The lower end of the receiving hopper (3) is provided with a discharge port (4). A partition (101) is fixedly connected to the inner side wall of the reaction tank (1). The inside of the reaction tank (1) is separated into a feed cavity and a reaction cavity that are distributed vertically by the partition (101). Inside the reaction tank (1) and below the partition (101), a reaction tank (21) for raw material reaction is rotatably connected by a first rotating shaft (20). A U-shaped frame is provided on one side of the reaction tank (21) away from the first rotating shaft (20). On one side of the U-shaped frame away from the reaction tank (21) and near the upper end, a sliding rod (32) is fixedly connected by two groups of first fixing seats (22). A sliding block (33) is slidably connected to the outer wall of the sliding rod (32). A spraying structure is provided on the sliding block (33) for spraying the mixed raw materials onto the left wall of the reaction tank (21) to form a continuous film. The spraying structure includes a spray head (34) and a metal mesh (35). The spray head (34) is fixedly connected to the left wall of the sliding block (33). One end of the spray head (34) facing the reaction tank (21) is provided with a spray nozzle (3401). The spray nozzle (3401) is strip-shaped. The metal mesh (35) is fixedly connected to the inner side wall of the spray head (34).

2. The pure PLA fabric production equipment according to claim 1, characterized in that: On the upper wall of the partition plate (101), three screw extruders (11) are fixedly connected in sequence from front to back. The inlet ends of the three screw extruders (11) are respectively connected to the catalyst storage tank (8) and two raw material storage tanks (9). The outlet ends of the three screw extruders (11) are all fixedly connected with conveying pipes (12). One end of the three conveying pipes (12) far from the screw extruders (11) is fixedly connected with a stirrer (15) through a joint (14). The outlet end of the stirrer (15) is fixedly connected with a connecting pipe (19). One end of the connecting pipe (19) far from the stirrer (15) penetrates through the inner wall of the partition plate (101) and extends to the lower side of the partition plate (101). Filters (13) are fixedly connected to the outer walls of the three conveying pipes (12). A stirring structure for stirring and mixing is arranged inside the stirrer (15). A translation driving structure for driving the sliding block (33) to move back and forth is arranged on the first fixed seat (22). One end of the connecting pipe (19) extending to the lower side of the partition plate (101) is connected to a spraying structure through a hose. An inclination adjusting structure for adjusting the angle between the reaction tank (21) and the horizontal plane is arranged inside the reaction tank (1). A temperature increasing structure for heating to dehydrate is arranged on the reaction tank (21). A temperature detection structure for detecting the reaction temperature is arranged on the side of the U-shaped frame far from the reaction tank (21) and below the first fixed seat (22). The left wall of the reaction tank (1) is fixedly connected with a negative pressure pipe (6) and a protective gas inlet pipe (5) in sequence from top to bottom. The negative pressure pipe (and the protective gas inlet pipe (5) are both communicated with the reaction chamber. One ends of the negative pressure pipe (6) and the protective gas inlet pipe (5) far from the reaction tank (1) are respectively connected to a negative pressure device and a protective gas providing device. Heat dissipation windows (7) for facilitating heat dissipation are arranged on the front wall and the rear wall of the feed chamber.

3. The pure PLA fabric production equipment according to claim 2, characterized in that: The stirring structure includes a second motor (16), a stirring shaft (17), and spiral blades (18). The second motor (16) is fixedly connected to the left end of the stirrer (15). The extending shaft of the second motor (16) penetrates through the left wall of the stirrer (15) and extends into the stirrer (15). The stirring shaft (17) is fixedly connected to the end of the extending shaft of the second motor (16). The spiral blades (18) are fixedly connected to the outer wall of the stirring shaft (17).

4. The pure PLA fabric production equipment according to claim 3, characterized in that: The translation driving structure includes a third motor (23) and a threaded rod (31). The third motor (23) is fixedly connected to the front wall of the frontmost one of the two first fixed seats (22). The extending shaft of the third motor (23) penetrates through the inner wall of the first fixed seat (22) and extends between the two first fixed seats (22). The threaded rod (31) is fixedly connected to the end of the extending shaft of the third motor (23). The outer wall of the threaded rod (31) penetrates through the inner wall of the sliding block (33) and is threadedly connected thereto. One end of the threaded rod (31) far from the third motor (23) is rotatably connected to the front wall of the rearmost one of the two first fixed seats (22).

5. The pure PLA fabric production equipment according to claim 4, characterized in that: The inclination angle adjustment structure includes a first motor (10), a second rotating shaft (24), and a cam (25). The first motor (10) is fixedly connected to the front wall of the reaction tank (1). The end of the extending shaft of the first motor (10) penetrates through the front wall of the reaction tank (1) and extends into the reaction chamber. The second rotating shaft (24) is fixedly connected to the end of the extending shaft of the first motor (10). The end of the second rotating shaft (24) far from the first motor (10) is rotatably connected to the inner rear wall of the reaction chamber. The cam (25) is fixedly connected to the outer wall of the second rotating shaft (24). The outer circumferential wall of the cam (25) is in sliding contact with the right wall of the reaction groove (21).

6. The pure PLA fabric production equipment according to claim 5, characterized in that: The temperature-raising structure includes multiple groups of heat conduction plates (30) and electric heating rods (26). Multiple groups of the heat conduction plates (30) are vertically distributed and fixedly connected to one side of the reaction groove (21) far from the first rotating shaft (20) in sequence. The distance between any two adjacent groups of the multiple groups of heat conduction plates (30) is equal. The left walls of the multiple groups of heat conduction plates (30) are flush with the left wall of the reaction groove (21). Multiple groups of the electric heating rods (26) are respectively fixedly connected to the inner side walls of a group of heat conduction plates (30).

7. The pure PLA fabric production equipment according to claim 6, characterized in that: The temperature detection structure includes multiple groups of temperature sensors (29). Multiple groups of second fixing seats (27) are vertically distributed and fixedly connected to the side of the U-shaped frame far from the reaction groove (21) and below the first fixing seat (22) in sequence. A fixing rod (28) is fixedly connected between two groups of the multiple groups of second fixing seats (27) corresponding to each other in the front and back. Multiple groups of the temperature sensors (29) are respectively fixedly connected to the outer walls of a group of fixing rods (28). The detection ends of the temperature sensors (29) face the left wall of the reaction groove (21).

8. A production process for pure PLA fabric, using the pure PLA fabric production equipment according to any one of claims 1 to 7, characterized in that: The production process includes the following steps: S1. Prepare materials. Prepare a catalyst, a first raw material, and a second raw material. Add the catalyst to the catalyst storage tank (8), and add the first raw material and the second raw material to a group of raw material storage tanks (9) respectively. Among them, the catalyst is an organic guanidine catalyst, the first raw material is D-lactide, and the second raw material is L-lactide; S2. Polymerize. The catalyst, the first raw material, and the second raw material are respectively extruded and fed through a group of screw extruders (11), and are jointly conveyed into the mixer (15). During the conveying process, they are fully filtered through the filter (13). The second motor (16) on the mixer (15) drives the stirring shaft (17) to rotate, and then drives the auger blades (18) to rotate, so as to fully stir the catalyst, the first raw material, and the second raw material entering the mixer (15) to form a mixture and convey it to the rear end; S3, open-loop reaction, the mixture enters the nozzle (34) through the connecting pipe (19) and the hose, and is sprayed toward the left wall of the reaction tank (21) through the nozzle (3401) on the nozzle (34). During the spraying process, the third motor (23) drives the threaded rod (31) to rotate. The threaded rod (31) drives the sliding block (33) to move axially along the sliding rod (32) through the threaded connection relationship between the threaded rod (31) and the sliding block (33). By changing the rotation direction of the third motor (23), the sliding block (33) moves back and forth, and then a continuous mixture is sprayed on the left wall of the reaction tank (21) through the nozzle (34). During the spraying process, the mixture is mixed again when passing through the metal mesh (35). Before spraying, the cam (25) is driven to rotate by the first motor (10) to adjust the angle between the left wall of the reaction tank (21) and the horizontal plane. A large angle can increase the downward flow rate of the mixture sprayed on the reaction tank (21), and conversely, a small angle can slow down the downward flow rate of the mixture. Due to the characteristic that the mixture flows downward along the left wall of the reaction tank (21), the mixture forms a thin film on the left wall of the reaction tank (21). In this process, the polymer film is subjected to step-by-step temperature control and heating by multiple sets of temperature sensors (29), heat conducting plates (30) and multiple sets of electric heating rods (26), which facilitates degassing and dehydration of the mixture. At the same time, the gas and water vapor inside the reaction chamber are extracted through the negative pressure pipe 6 by the negative pressure device, and the protective gas is fed into the protective gas inlet pipe (5). The mixture after the reaction forms a polylactic acid fluid, which flows into the receiving hopper (3) by its own weight, and is extracted by the discharge pump through the discharge port (4) and then fed into the granulation equipment for cooling and granulation to form PLA particles. S4. The PLA pellets are melt-spun through a spinning device to form PLA fiber filaments, the PLA fiber filaments are heat-set through a fiber processing device, and then woven into pure PLA fabrics through a weaving device.

9. The pure PLA fabric according to claim 8, characterized in that: The pure PLA fabric is produced using the production process of the pure PLA fabric according to claim 8.

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