A phb resin particle and a method for producing the same

Abstract

The application provides a PHA resin particle and a preparation method thereof, and the preparation method of the PHA resin comprises the following steps: S100, master batch preparation: after a PHA matrix is mixed with an additive, the mixture is subjected to melt extrusion and cooling granulation to obtain a master batch; S200, spinning: after the master batch is melted, the master batch is spun by centrifugal force under the action of a supergravity field, and then cooled and solidified into a PHA fiber; S300, crushing: the PHA fiber is cut and ground to obtain a PHA resin particle. The PHA fiber is prepared by using a centrifugal spinning method, the spinning efficiency is improved, and the shape of a spinning hole can be selected according to needs, so that the product can adapt to different needs.

Description

Technical Field

[0001] This invention relates to the field of resins, and more specifically, to a PHA resin particle and its preparation method. Background Technology

[0002] PHA resin is widely used due to its similar physicochemical properties to chemically synthesized plastics, as well as its excellent characteristics such as complete biodegradability and biocompatibility. Currently, PHA resin is typically prepared by melt spinning followed by cutting and pulverizing. However, the limited operating temperature range for melt spinning of PHA resin leads to low spinning efficiency, which in turn limits the preparation efficiency of PHA resin particles. Therefore, improving the preparation efficiency of PHA resin particles has been a long-standing goal for researchers. Summary of the Invention

[0003] The present invention aims to solve at least one of the above-mentioned technical problems.

[0004] Therefore, the first objective of this invention is to provide a method for preparing PHA resin particles.

[0005] A second objective of this invention is to provide a PHA resin particle.

[0006] To achieve the first objective of this invention, embodiments of this invention provide a method for preparing PHA resin particles, comprising: S100, masterbatch preparation: mixing a PHA matrix with an additive, followed by melt extrusion, cooling and granulation to obtain a masterbatch; S200, spinning: melting the masterbatch, spinning it under centrifugal force in a hypergravity field, and then cooling and solidifying it into PHA fiber filaments; S300, pulverizing: cutting and grinding the PHA fiber filaments to obtain PHA resin particles.

[0007] This invention primarily prepares PHA resin granules through three steps: masterbatch preparation, spinning, and pulverization. First, PHA resin is mixed with additives and melt-extruded to obtain masterbatch. The presence of additives improves the properties of the PHA resin, resulting in better performance of the prepared PHA resin granules. The obtained masterbatch is then centrifugally spun into PHA fiber filaments. Centrifugal spinning offers advantages such as high fiber production efficiency, simple equipment, and wide material adaptability. Therefore, using centrifugal spinning to prepare PHA fiber filaments not only improves spinning efficiency but also produces PHA fiber filaments with suitable size and shape for subsequent operations. The PHA fiber filaments are then cut and pulverized to obtain PHA resin granules. This process for preparing PHA resin granules is not only simple and efficient but also allows for the improvement of properties such as thermal stability of the PHA resin through additives, resulting in PHA resin with superior performance.

[0008] In addition, the technical solutions provided by the above embodiments of the present invention may also have the following technical features:

[0009] In the above technical solution, S200 includes: S210, preparation of spinning melt: the masterbatch is introduced into the extruder and melted to form spinning melt; S220, the spinning melt is transferred to a centrifugal spinning machine, and under the action of centrifugal force, it is spun through the spinning hole and then quickly condensed and solidified into PHA fiber filaments.

[0010] The masterbatch is melt-extruded to obtain a spinning melt, which is then thrown out of the spinning orifice of the centrifugal spinning machine by centrifugal force. The centrifugal force can not only produce a certain compaction effect on the spinning melt, causing the spinning melt to be pressed out of the spinning orifice, but also exert a certain stretching effect on the spinning melt pressed out of the spinning orifice, ultimately obtaining PHA fiber filaments. The hypergravity field accelerates the driving force of the relative motion between different substances, thereby reducing the spinning time and improving the spinning efficiency.

[0011] In any of the above technical solutions, the melting temperature is 200℃-300℃; and / or the acceleration of the hypergravity field is 10g-100g; and / or the rotational speed of the centrifugal spinning machine is 5000rpm-15000rpm; and / or the length of the PHA fiber is 5mm-300mm; where g is the gravitational acceleration of the Earth.

[0012] After the masterbatch is melted, it is extruded through a screw extruder. PHA fibers can achieve a better melting effect by using the above-mentioned melting temperature. A supergravity field refers to an environment where the acceleration is greater than the acceleration caused by Earth's gravity. The effect produced by the above-mentioned acceleration is better. The centrifugal force generated by the centrifugal spinning machine at the above-mentioned speed can achieve a better spinning effect. The length of the PHA fiber filaments within the above-mentioned range is beneficial to subsequent processing steps.

[0013] In any of the above technical solutions, in S220, the spinning melt is thrown out of the spinning hole by centrifugal force in the rotating drum of the centrifugal spinning machine, and after rapid cooling and solidification, it is wrapped and collected on the collector; the rotation speed of the collector is 10 rpm-350 rpm.

[0014] The spinning melt is subjected to centrifugal force in the rotating drum of the centrifugal spinning machine. Under the action of centrifugal force, it is thrown onto the inner wall of the rotating drum and compacted by centrifugal force to create spinning holes. Then, under the action of centrifugal force, it is stretched into PHA fiber filaments. The PHA fiber filaments are collected by a collector outside the rotating drum. The collector winds the PHA fiber filaments onto itself by rotating. The collector adopts the above-mentioned rotation speed to collect the PHA fiber filaments better.

[0015] In any of the above technical solutions, there is an air field between the rotating drum and the collector; the air field is used to cool and solidify the PHA fiber filaments that are thrown out of the spinning holes; the air field is generated by the temperature control system at the bottom of the centrifugal spinning machine; the pressure of the air field is 100Pa-300Pa.

[0016] The airflow is generated by the temperature control system. The condensing air generated by the temperature control system forms an airflow between the rotating drum and the collector. The function of the condensing air is to cool the PHA fiber filaments that are thrown out of the spinning holes by centrifugal force. In addition, the presence of the airflow can further refine the fiber stretching and orientation. The fiber stretching and orientation refinement effect is better when the airflow intensity is 100Pa-300Pa.

[0017] In any of the above technical solutions, the temperature control system includes: a temperature control box, which is used to generate the wind required for the wind field; an air nozzle, which is used to spray the wind generated by the temperature control box to form a wind field; the angle between the air nozzle and the bottom surface of the centrifugal spinning machine is 0°-180°.

[0018] The temperature control system consists of a temperature control box and air nozzles. The condensing air is generated by the temperature control system and sprayed out by the air nozzles. The air nozzles are located at the bottom of the centrifugal spinning machine. The air nozzles can spray the condensing air at any angle. After the PHA fiber filaments are sprayed out of the spinning orifice, they continue to be stretched, oriented and refined by the condensing air. The condensing air also has a certain traction effect.

[0019] In any of the above technical solutions, an electrostatic field is also applied between the rotating cylinder and the collector; the electrostatic field is used to draw the cooled and solidified PHA fibers to the collector.

[0020] Air nozzles are installed at the bottom of the centrifugal spinning machine, causing the PHA fibers to be pulled upward by the condensing air. Since there is a certain distance between the rotating drum and the collector, an electrostatic field is applied between the collector and the rotating drum to improve the collection efficiency of the collector. The electrostatic force generated by the electrostatic field can pull the PHA fibers to the collector. The collector winds the PHA fibers onto it by rotating.

[0021] In any of the above technical solutions, the shape of the spinning hole includes any one or more of the following: circular, semi-circular, elliptical, triangular, square, and irregular shapes; wherein, when the spinning hole is circular, the diameter is 10μm-35μm.

[0022] The shape of the spinning hole can be selected according to the needs. The shape of the spinning hole can be any one or more of the following: circular, semi-circular, elliptical, triangular, square, or irregular, so that the PHA fiber filaments produced can meet different requirements. When the spinning hole is circular, the diameter should be in the range of 10μm-35μm to produce PHA fiber filaments suitable for subsequent processing steps.

[0023] In any of the above technical solutions, in S100, the mass ratio of PHA matrix additives is (80-120):(10-30); and / or the PHA matrix includes at least one of P3HB, PHV and PHBV; and / or the additives include at least one of heat stabilizer, antioxidant, anti-blocking agent and coupling agent; and / or the melt extrusion temperature is 220℃-350℃.

[0024] The PHA resin particles prepared using the above-mentioned proportions and types of PHA matrix and additives have good performance; at 220℃-350℃, the mixed PHA matrix and additives can be completely melted and the effect is good.

[0025] To achieve the second objective of this invention, an embodiment of this invention provides a PHA resin particle, which is prepared by the preparation method of any of the above-described technical solutions.

[0026] The PHA resin particles of the present invention can be prepared from the preparation method of PHA resin particles as described in any embodiment of the present invention. The PHA resin particles of the present invention have all the beneficial effects of the preparation method of PHA resin particles as described in any embodiment of the present invention, which will not be repeated here.

[0027] By adopting the technical solution of the present invention, the following technical effects can be achieved:

[0028] 1. PHA fiber filaments are prepared by centrifugal spinning, which improves spinning efficiency and allows for selection of the shape of the spinning holes as needed, enabling the product to meet different requirements;

[0029] 2. Being in a hypergravity field during centrifugal spinning accelerates the process and improves its efficiency.

[0030] 3. The air nozzles are located at the bottom of the centrifugal spinning machine, which can fully cool the PHA fiber filaments and further stretch, orient, and refine the PHA fiber filaments;

[0031] 4. An electrostatic field is applied between the rotating drum and the collector, and the PHA fibers are drawn to the collector by electrostatic force and are wound and collected, which improves the collection efficiency of the PHA fibers. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a centrifugal spinning machine according to an embodiment of the present invention;

[0033] Figure 2 This is a flowchart illustrating the preparation process of PHA resin particles according to an embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 100-Screw extruder; 110-Raw material tank; 111-PHA matrix tank; 112-Auxiliary agent tank; 120-Masterbatch preparer; 130-Filter; 200-Centrifugal spinning machine; 210-Rotating drum; 211-Spinning orifice; 220-Collector; 230-Air nozzle; 240-PHA fiber; 300-Ball mill. Detailed Implementation

[0036] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0037] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the following description is provided in conjunction with... Figures 1 to 2 Specific embodiments of the present invention will be described in detail below.

[0039] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a method for preparing PHA resin particles, comprising: S100, masterbatch preparation: mixing PHA matrix with additives, followed by melt extrusion, cooling and granulation to obtain masterbatch; S200, spinning: melting the masterbatch, spinning it under centrifugal force in a hypergravity field, and then cooling and solidifying it into PHA fiber filaments 240; S300, pulverizing: cutting and grinding the PHA fiber filaments 240 to obtain PHA resin particles.

[0040] In related technologies, PHA resin particles are produced by melt spinning followed by cutting and grinding. However, the operable temperature range during PHA resin melt spinning is limited, resulting in low production efficiency.

[0041] In view of this, the present invention provides a method for preparing PHA resin particles, wherein PHA fiber filaments 240 are prepared by centrifugal spinning, and the process is carried out in a gravitational field to improve the preparation efficiency of PHA fiber filaments 240, thereby improving the preparation efficiency of PHA resin particles.

[0042] Specifically, this invention mainly prepares PHA resin particles through three steps: masterbatch preparation, spinning, and pulverization. The PHA matrix in the PHA matrix tank 111 and the additives in the additive tank 112 are mixed evenly in the raw material tank 110. The additives improve the performance of the PHA resin, resulting in better performance of the prepared PHA resin particles. The mixed PHA matrix and additives are melted in the masterbatch preparer 120 to obtain a masterbatch. The obtained masterbatch is melted again and then centrifugally spun into PHA fiber filaments 240 in a hypergravity field. Centrifugal spinning has advantages such as high fiber preparation efficiency, simple equipment, and wide material adaptability. Using centrifugal spinning to prepare PHA fiber filaments 240 not only improves spinning efficiency but also produces PHA fiber filaments 240 with suitable size and shape for subsequent operations. The hypergravity field accelerates the movement of PHA, improving spinning efficiency. After the PHA fiber filaments 240 are cut and pulverized, PHA resin particles are obtained. The process of preparing PHA resin particles using this method is not only simple and efficient, but also allows for the improvement of properties such as thermal stability of PHA resin through the use of additives, resulting in PHA resin with better performance.

[0043] Preferably, PHA fiber filament 240 is cut at the feed inlet of ball mill 300 and then pulverized by ball milling to obtain PHA resin particles. The mass ratio of grinding media to PHA fiber in ball mill 300 is (3-7):1. The grinding media includes large balls and small balls, and the ratio of large balls to small balls is 1:2.

[0044] In some embodiments of the present invention, S200 includes: S210, preparation of spinning melt: introducing masterbatch into an extruder and melting it to form spinning melt; S220, transferring the spinning melt to a centrifugal spinning machine 200, and rapidly cooling and solidifying it into PHA fiber filament 240 under the action of centrifugal force through the spinning hole 211 under the action of centrifugal force in a hypergravity field.

[0045] Preferably, before centrifugal spinning, the masterbatch is first melt-extruded to obtain a spinning melt, and then the spinning melt is transferred to a centrifugal spinning machine 200. The spinning melt is thrown out of the spinning hole 211 of the centrifugal spinning machine 200 by centrifugal force. The centrifugal force can not only produce a certain compaction effect on the spinning melt, so that the spinning melt is pressed out of the spinning hole 211, but also play a certain stretching effect on the spinning melt pressed out of the spinning hole 211, and finally obtain PHA fiber filament 240.

[0046] Preferably, the hypergravity field has a driving force on the spinning melt, which accelerates the extrusion of the spinning melt into the spinning orifice 211, thereby reducing the time required for spinning and improving the spinning efficiency. Furthermore, the hypergravity field is also beneficial for improving the defects of PHA resin.

[0047] Preferably, after the spinning melt is extruded through the screw extruder, it is filtered by the filter 130 and then enters the centrifugal spinning machine 200. The filter 130 can filter out impurities, making the PHA resin particles of the vegetation perform better.

[0048] In some embodiments of the present invention, the melting temperature is 200°C-300°C; and / or the acceleration of the hypergravity field is 10g-100g; and / or the rotational speed of the centrifugal spinning machine 200 is 5000rpm-15000rpm; and / or the length of the PHA fiber filament 240 is 5mm-300mm; wherein, g is the gravitational acceleration of the Earth.

[0049] Preferably, the prepared masterbatch can be completely melted at a temperature of 200℃-300℃ with good results, and is then extruded through a screw extruder 100 after melting; a hypergravity field refers to an environment where the acceleration is greater than the acceleration of Earth's gravity, and a hypergravity field with an acceleration of 10g-100g produces good results; the centrifugal force generated when the speed of the centrifugal spinning machine 200 is 5000rpm-15000rpm can achieve a good spinning effect; the length of the obtained PHA fiber filament 240 is 5mm-300mm, and this length of PHA fiber filament 240 is more suitable for subsequent processing steps.

[0050] In some embodiments of the present invention, in S220, the spinning melt is thrown out of the spinning hole 211 by centrifugal force in the rotating drum 210 of the centrifugal spinning machine 200, and after rapid cooling and solidification, it is wound and collected on the collector 220; the rotation speed of the collector 220 is 10 rpm-350 rpm.

[0051] Preferably, the rotating drum 210 rotates at a certain speed to generate centrifugal force. During this process, the spinning melt is thrown onto the inner wall of the rotating drum 210 due to the centrifugal force and is compacted by the centrifugal force, thus squeezing out the spinning holes 211. At the same time, the centrifugal force also has a certain stretching effect on the spinning melt that has been squeezed out of the spinning holes 211. Under the action of centrifugal force, the spinning melt is stretched into PHA fiber filaments 240. The PHA fiber filaments 240 are collected by the collector 220 outside the rotating drum 210. The collector 220 winds the PHA fiber filaments 240 around itself by rotating. When the rotation speed of the collector 220 is 10-350 rpm, the collection effect of the PHA fiber filaments 240 is better.

[0052] In some embodiments of the present invention, there is an airflow between the rotating drum 210 and the collector 220; the airflow is used to cool and solidify the PHA fiber filaments 240 that are thrown out of the spinning holes 211; the airflow is generated by a temperature control system at the bottom of the centrifugal spinning machine 200; the pressure of the airflow is 100Pa-300Pa.

[0053] Preferably, the presence of the airflow can cool and solidify the PHA fiber filaments 240 extruded from the spinning holes 211. The airflow is formed by the condensing air generated by the temperature control system in the centrifugal spinning machine 200. The condensing air forms an airflow between the rotating drum 210 and the collector 220. Furthermore, the presence of the airflow can further refine the fiber stretching and orientation. The fiber stretching and orientation refinement effect is better when the airflow intensity is 100Pa-300Pa.

[0054] In some embodiments of the present invention, the temperature control system includes: a temperature control box for generating the wind required for the wind field; an air nozzle 230 for spraying the wind generated by the temperature control box to form the wind field; and the angle between the air nozzle 230 and the bottom surface of the centrifugal spinning machine 200 is 0°-180°.

[0055] Preferably, the temperature control system consists of a temperature control box and an air nozzle 230. The condensing air is generated by the temperature control box located inside the base of the centrifugal spinning machine 200 and ejected by the air nozzle 230 extending from the bottom surface of the centrifugal spinning machine 200. The air nozzle 230 is located between the rotating cylinder 210 and the collector 220. The air nozzle 230 can eject the condensing air at any angle. While cooling the PHA fiber 240, the condensing air ejected by the air nozzle 230 can also further stretch the PHA fiber 240, making the PHA fiber 240 stretch and finer.

[0056] Preferably, the condensed air ejected by the air nozzle 230 can also apply a traction force to the PHA fiber 240, which can pull the PHA fiber 240 closer to the collector 220 and be collected by the collector 220 through rotation.

[0057] In some embodiments of the present invention, an electrostatic field is also applied between the rotating cylinder 210 and the collector 220; the electrostatic field is used to draw the cooled and solidified PHA fiber filaments 240 to the collector 220.

[0058] Preferably, the air nozzle 230 is installed at the bottom of the centrifugal spinning machine 200, so that the PHA fiber 240 is pulled upward by the condensing air. Since there is a certain distance between the rotating drum 210 and the collector 220, in order to improve the collection efficiency of the collector 220, an electrostatic field is applied between the collector 220 and the rotating drum 210. The electrostatic force generated by the electrostatic field and the traction force of the condensing air generated by the air nozzle 230 jointly pull the PHA fiber 240 to the collector 220. The collector 220 winds the PHA fiber 240 around itself by rotating.

[0059] Preferably, in some embodiments of the present invention, the shape of the spinning hole 211 includes any one or more of the following: circular, semi-circular, elliptical, triangular, square, and irregular shapes; wherein, when the spinning hole 211 is circular, the diameter is 10μm-35μm.

[0060] The shape of the spinning hole 211 can be selected as needed. The shape of the spinning hole 211 can be any one or more of the following: circular, semi-circular, elliptical, triangular, square, or irregular, so that the PHA fiber filament 240 produced can meet different requirements. When the spinning hole 211 is circular, the diameter should be in the range of 10μm-35μm, and the PHA fiber filament 240 produced is suitable for subsequent processing steps.

[0061] In some embodiments of the present invention, in S100, the mass ratio of PHA matrix additives is (80-120):(10-30); and / or the PHA matrix includes at least one of P3HB, PHV and PHBV; and / or the additives include at least one of heat stabilizer, antioxidant, anti-blocking agent and coupling agent; and / or the melt extrusion temperature is 220°C-350°C.

[0062] Preferably, the PHA resin particles prepared using the above-mentioned proportions and types of PHA matrix and additives have better performance; at 220℃-350℃, the mixed PHA matrix and additives can be completely melted and the effect is good.

[0063] Preferably, the PHA matrix can be selected from one or a mixture of P3HB, PHV and PHBV, wherein PHBV is a mixture of P3HB and PHV, and P3HB, PHV and PHBV all have good properties.

[0064] Preferably, the antioxidant includes at least one of antioxidant CA, LOWINOX 44B25, antioxidant RIANOX 1098, antioxidant RIANOX 1790, antioxidant RIANOX 168, and antioxidant RIANOX 626; the heat stabilizer includes at least one of magnesium 2-ethylhexanoate, zinc 2-ethylhexanoate, zinc stearate, calcium stearate, calcium laurate, and magnesium laurate; the anti-blocking agent includes at least one of oleamide, stearamide, BYK3700 silicone leveling agent, silica opening agent AB-MB-09, and antistatic agent MOA3-PK; and the coupling agent includes at least one of silane coupling agent Z-6020, silane coupling agent KH-550, silane coupling agent KBM-602, TTS, and KR-38S.

[0065]

Example 1

[0066] S100, Masterbatch Preparation: PHA matrix and additives are mixed at a mass ratio of 80:10, then melt-extruded at 220℃, cooled and granulated to obtain masterbatch;

[0067] S210, Preparation of spinning melt: The masterbatch is introduced into the extruder and melted at 200℃ to form a spinning melt;

[0068] S220. The spinning melt is transferred to a centrifugal spinning machine. Under the action of a hypergravity field with an acceleration of 10g, the centrifugal spinning machine rotates at 5000 rpm. After being spun through the spinning hole by centrifugal force, it is quickly condensed and solidified into PHA fiber filaments. The air field used for condensation and solidification is sprayed out by an air nozzle with an angle of 0° and an air field intensity of 100Pa. The obtained PHA fiber filaments are wound and collected by a collector with a rotation speed of 10 rpm.

[0069] S300, Crushing: PHA fiber filaments are cut and then ball-milled to obtain PHA resin particles; the mass ratio of the ball milling media to PHA fiber is 3:1, and the ratio of large balls to small balls in the ball milling media is 1:2.

[0070]

Example 2

[0071] S100, Masterbatch preparation: PHA matrix and additives are mixed at a mass ratio of 120:30, then melt-extruded at 350℃, cooled and granulated to obtain masterbatch;

[0072] S210, Preparation of spinning melt: The masterbatch is introduced into the extruder and melted at 300℃ to form a spinning melt;

[0073] S220. The spinning melt is transferred to a centrifugal spinning machine. Under the action of a hypergravity field with an acceleration of 100g, the centrifugal spinning machine rotates at 15000 rpm. After being spun through the spinning hole by centrifugal force, it is quickly condensed and solidified into PHA fiber filaments. The air field used for condensation and solidification is sprayed out by an air nozzle with an angle of 180° and an air field intensity of 300Pa. The obtained PHA fiber filaments are wound and collected by a collector with a rotation speed of 350 rpm.

[0074] S300, Crushing: PHA fiber filaments are cut and then ball-milled to obtain PHA resin particles; the mass ratio of ball milling media to PHA fiber is 7:1, and the ratio of large balls to small balls in the ball milling media is 1:2.

[0075]

Example 3

[0076] S100, Masterbatch Preparation: PHA matrix and additives are mixed at a mass ratio of 100:20, then melt-extruded at 220℃, cooled and granulated to obtain masterbatch;

[0077] S210, Preparation of spinning melt: The masterbatch is introduced into the extruder and melted at 250°C to form a spinning melt;

[0078] S220. The spinning melt is transferred to a centrifugal spinning machine. Under the action of a hypergravity field with an acceleration of 50g, the centrifugal spinning machine rotates at 8000 rpm. After being spun through the spinning hole by centrifugal force, it is quickly condensed and solidified into PHA fiber filaments. The air field used for condensation and solidification is sprayed out by an air nozzle with an angle of 90° and an air field intensity of 200Pa. The obtained PHA fiber filaments are wound and collected by a collector with a rotation speed of 150 rpm.

[0079] S300, Crushing: PHA fiber filaments are cut and then ball-milled to obtain PHA resin particles; the mass ratio of ball milling media to PHA fiber is 5:1, and the ratio of large balls to small balls in the ball milling media is 1:2.

[0080]

Example 4

[0081] S100, Masterbatch Preparation: PHA matrix and additives are mixed at a mass ratio of 100:20, then melt-extruded at 220℃, cooled and granulated to obtain masterbatch;

[0082] S210, Preparation of spinning melt: The masterbatch is introduced into the extruder and melted at 235°C to form a spinning melt;

[0083] S220. The spinning melt is transferred to a centrifugal spinning machine. Under the action of a hypergravity field with an acceleration of 45g, the centrifugal spinning machine rotates at 7500 rpm. After being spun through the spinning hole by centrifugal force, it is quickly condensed and solidified into PHA fiber filaments. The air field used for condensation and solidification is sprayed out by an air nozzle with an angle of 70° and an air field intensity of 200Pa. The obtained PHA fiber filaments are wound and collected by a collector with a rotation speed of 80 rpm.

[0084] S300, Crushing: PHA fiber filaments are cut and then ball-milled to obtain PHA resin particles; the mass ratio of ball milling media to PHA fiber is 4:1, and the ratio of large balls to small balls in the ball milling media is 1:2.

[0085] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0086] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for preparing PHA resin particles, characterized in that, include: S100, Masterbatch preparation: The PHA matrix and additives are mixed and then melt-extruded, cooled and granulated to obtain the masterbatch; S200, spinning: The masterbatch is melted and then spun under centrifugal force in a super gravity field and then cooled and solidified into PHA fiber filaments (240); S300, Crushing: The PHA fiber filaments (240) are cut and ground into powder to obtain the PHA resin particles; S200 includes: S210, preparation of spinning melt: the masterbatch is introduced into an extruder and melted to form the spinning melt; S220. The spinning melt is transferred to a centrifugal spinning machine (200). Under the action of centrifugal force, it is spun through the spinning hole (211) and then rapidly cooled and solidified into the PHA fiber filament (240). The spinning melt is spun out of the spinning hole (211) in the rotating drum (210) of the centrifugal spinning machine (200) by centrifugal force, and after rapid cooling and solidification, it is wound and collected on the collector (220). There is an airflow between the rotating drum (210) and the collector (220); the airflow is used to cool and solidify the PHA fiber filaments (240) that are thrown out of the spinning orifice (211); the airflow is generated by a temperature control system at the bottom of the centrifugal spinning machine (200); The temperature control system includes: a temperature control box, which is used to generate the wind required for the wind field; an air nozzle (230), which is used to spray the wind generated by the temperature control box to form the wind field; the air nozzle is set at the bottom of the centrifugal spinning machine, and the angle between the air nozzle (230) and the bottom surface of the centrifugal spinning machine (200) is 0°-180°; An electrostatic field is also applied between the rotating cylinder (210) and the collector (220); the electrostatic field is used to draw the cooled and solidified PHA fiber filaments (240) to the collector (220); Wherein, the melting temperature is 235℃-300℃; the acceleration of the hypergravity field is 45g-100g; the rotational speed of the centrifugal spinning machine (200) is 7500rpm-15000rpm; where g is the gravitational acceleration of the Earth.

2. The preparation method according to claim 1, characterized in that, The length of the PHA fiber filament (240) is 5mm-300mm.

3. The preparation method according to claim 1, characterized in that, In S220, The collector (220) has a rotation speed of 10 rpm to 350 rpm.

4. The preparation method according to claim 1, characterized in that... ； The pressure of the wind field is 100Pa-300Pa.

5. The preparation method according to claim 1, characterized in that, The shape of the spinning hole (211) includes any one or more of the following: circular, semi-circular, elliptical, triangular, square, and irregular shapes; When the spinning hole (211) is circular, its diameter is 10μm-35μm.

6. The preparation method according to claim 1, characterized in that, In the S100, The mass ratio of the PHA matrix to the auxiliary agent is (80-120):(10-30); and / or The PHA matrix includes at least one of P3HB, PHV, and PHBV; and / or The additives include at least one of heat stabilizers, antioxidants, anti-blocking agents, and coupling agents; and / or The temperature of the melt extrusion is 220℃-350℃.

7. A PHA resin particle, characterized in that, Prepared by the method according to any one of claims 1-6.

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