Biobased degradable printing materials and methods of making the same

Abstract

This invention relates to the field of bio-based polymer materials technology, specifically a bio-based biodegradable printing material and its preparation method. The method includes: establishing a production system; conveying bio-based raw materials to the reaction end; introducing nitrogen to adjust the flow rate; heating the raw materials to induce an esterification reaction; monitoring the amount of water generated; stopping the reaction when a threshold is reached to obtain the esterified product; conveying the esterified product to a melt polycondensation device; vacuum heating; monitoring the vacuum level to ensure it reaches the target level; stirring to induce a polycondensation reaction; monitoring the stirring torque; stopping the reaction when a threshold is reached to obtain a molten copolyester; cooling and solidifying the molten copolyester; cutting it into granules; vacuum drying; hot pressing to obtain a cooled preform; and then treating with low-temperature plasma to obtain the target printing material. This invention enables the efficient and stable preparation of bio-based biodegradable printing materials, significantly improving the printability and surface hydrophilicity of the material while maintaining excellent biodegradability and mechanical strength.

Description

Technical Field

[0001] This invention relates to the field of bio-based polymer materials technology, and in particular to a bio-based biodegradable printing material and its preparation method. Background Technology

[0002] With the rapid growth in demand for green printing, bio-based biodegradable printing materials have become a key technology for replacing traditional petroleum-based printing films and achieving sustainable development in the printing industry. Against this backdrop, bio-based printing materials face severe technical bottlenecks in large-scale preparation, including insufficient surface hydrophilicity and printability. Significantly improving the wettability and adhesion to water-based inks while ensuring complete biodegradability is crucial for promoting the industrial application of environmentally friendly printing materials.

[0003] Traditional printing materials often use polyester or polyolefin films as substrates, which have low surface polarity and strong hydrophobicity. Untreated films typically have a contact angle of over 90° with water-based inks, leading to uneven ink spread, blurred printing patterns, or flaking. Existing improvement methods often employ offline corona treatment, but this approach suffers from drawbacks such as fluctuating treatment intensity with film distance, unstable output due to electrode temperature drift, and difficulty in integrating with continuous production lines. This results in significant differences in printing quality across different areas of the same roll of material, and the treatment effect degrades over time, severely restricting the quality and batch stability of bio-based printing materials for industrial application. Summary of the Invention

[0004] This invention provides a bio-based biodegradable printing material and its preparation method, as well as a computer-readable storage medium. Its main purpose is to achieve efficient and stable preparation of bio-based biodegradable printing materials, significantly improve the printability and surface hydrophilicity of the materials, while maintaining excellent biodegradability and mechanical strength.

[0005] To achieve the above objectives, the present invention provides a bio-based biodegradable printing material and its preparation method, comprising:

[0006] The system receives a printing material preparation instruction and confirms the printing material production system according to the instruction. The printing material production system includes: a material conveying device, an esterification reaction device, a gas conduction device, a melt polycondensation device, a particle cutting device, a vacuum drying device, a hot pressing device, and a plasma treatment device. The esterification reaction device consists of an inlet end, a reaction end, and an exhaust end.

[0007] Obtain bio-based raw materials and use the material conveying device to transport the bio-based raw materials to the reaction end;

[0008] A water volume threshold is set, and nitrogen is introduced into the gas inlet using the gas conduction device. The flow rate of nitrogen is adjusted in real time by monitoring the exhaust end. The bio-based raw material at the reaction end is heated and esterification reaction is carried out. The water volume generated by the esterification reaction device is monitored in real time. When the water volume generated reaches the set water volume threshold, the esterification reaction is stopped to obtain the esterification product.

[0009] The esterified product is transported to the melt polycondensation device. The target vacuum level and target torque value are set. The esterified product in the melt polycondensation device is heated and vacuum treatment is performed. The vacuum level in the melt polycondensation device is monitored in real time. When the vacuum level reaches the set target vacuum level, the esterified product is stirred and melt polycondensation reaction is carried out. At the same time, the stirring torque during the stirring process is monitored. When the stirring torque reaches the set target torque value, the heating, stirring and melt polycondensation reaction are stopped to obtain molten copolyester.

[0010] The molten copolyester is cooled and solidified, and the solidified molten copolyester is cut into copolyester particles using the particle cutting device. The copolyester particles are then vacuum dried using the vacuum drying device to obtain dried copolyester particles.

[0011] The dried copolyester particles are preheated, pressure-held, and cooled sequentially using the hot pressing molding device to obtain a cooled blank. The cooled blank is then subjected to low-temperature plasma treatment using the plasma treatment device to obtain the target bio-based biodegradable printing material.

[0012] Optionally, the step of introducing nitrogen gas into the inlet using the gas conduction device and adjusting the nitrogen flow rate in real time by monitoring the exhaust end includes:

[0013] The gas conduction device is confirmed to include an oxygen sensor, a coarse adjustment flow meter, a fine adjustment flow meter, and a nitrogen inlet pipeline, and the gas conduction device is connected to the esterification reaction device.

[0014] Initialize the oxygen sensor and use the oxygen sensor to collect the oxygen content monitoring value at the exhaust end of the esterification reaction device in real time;

[0015] Set a replacement completion threshold and a target oxygen content threshold, wherein the replacement completion threshold is lower than the target oxygen content threshold;

[0016] The gas phase space volume of the esterification reaction apparatus and the required reaction temperature of the esterification reaction are obtained. The first nitrogen flow rate is calculated based on the gas phase space volume and the required reaction temperature. The coarse adjustment target flow rate is set based on the first nitrogen flow rate, wherein the coarse adjustment target flow rate is less than the first nitrogen flow rate.

[0017] The coarse adjustment flow meter and the fine adjustment flow meter are integrated in series in the nitrogen inlet pipeline. The coarse adjustment flow meter is turned on to adjust the nitrogen flow rate to the coarse adjustment target flow rate. Then, the flow rate is compensated by the fine adjustment flow meter to compensate the nitrogen flow rate to the first nitrogen flow rate. The first nitrogen flow rate is used to replace the air in the esterification reaction device.

[0018] Set a second nitrogen flow rate, wherein the second nitrogen flow rate is less than the first nitrogen flow rate. Compare the oxygen content monitoring value with the set replacement completion threshold in real time. When the oxygen content monitoring value is continuously lower than the replacement completion threshold, turn off the coarse adjustment flow meter and use the fine adjustment flow meter to switch the nitrogen flow rate to be maintained at the second nitrogen flow rate.

[0019] Nitrogen gas is continuously introduced into the inlet at the second nitrogen flow rate until the esterification reaction experiment is completed.

[0020] Optionally, initializing the oxygen sensor and using the oxygen sensor to collect real-time oxygen content monitoring values ​​at the exhaust end of the esterification reaction device includes:

[0021] To verify the oxygen sensor, introduce oxygen-free calibration nitrogen gas with a purity ≥99.99% into the oxygen sensor. Once the output value of the oxygen sensor stabilizes, read the output value of the oxygen sensor at this time as the zero-point output value.

[0022] Standard air is switched to the oxygen sensor, wherein the oxygen content of the standard air is known. When the output value of the oxygen sensor stabilizes, the output value of the oxygen sensor at this time is read as the range output value.

[0023] Based on the zero-point output value, the range output value, and the known oxygen content of the standard air, a linear correspondence between the output value of the oxygen sensor and the oxygen content is established through a linear fitting algorithm.

[0024] set up For each set of temperature values, the fitted relationship between the output value of the oxygen sensor and the oxygen content is obtained. Based on the fitted relationship, a temperature compensation function is further fitted to obtain the temperature compensation function.

[0025] During the esterification reaction, the output value of the oxygen sensor is continuously collected, and the real-time gas temperature at the exhaust end of the esterification reaction device is obtained. The real-time gas temperature is substituted into the temperature compensation function to calculate the temperature compensation coefficient.

[0026] The output value of the oxygen sensor is multiplied by the temperature compensation coefficient to obtain the real-time compensation output value. The real-time compensation output value is then substituted into the linear correspondence to convert the oxygen content monitoring value, thus completing the real-time oxygen content detection.

[0027] Optionally, the setting For each set of temperature values, the fitted relationship between the oxygen sensor output value and the oxygen content is obtained. Based on the fitted relationship, a temperature compensation function is further fitted, including:

[0028] Record the output value of the oxygen sensor for each set of temperature values, and take the natural logarithm of the output value of the oxygen sensor for each set of temperature values;

[0029] The temperature value and the output value after taking the natural logarithm were linearly fitted using the least squares method, and the fitting coefficient was calculated according to the following formula:

[0030] ;

[0031] in, The number of temperature value groups. For each group of temperature values, The output value of the oxygen sensor for each set of temperature values. and These are the fitting coefficients;

[0032] According to the fitting coefficients and The temperature compensation function is constructed. ,in, This is the temperature compensation coefficient.

[0033] Optionally, the flow compensation process performed by the fine-tuning flow meter to compensate the nitrogen flow rate to the first nitrogen flow rate includes:

[0034] Multiple instantaneous flow rates of nitrogen in the nitrogen inlet pipeline are continuously collected, and the instantaneous flow rates are processed by moving average filtering to obtain a unique actual flow rate value after filtering.

[0035] Set the deviation dead zone threshold and adjustment step size, and calculate the difference between the actual flow rate and the first nitrogen flow rate to obtain the flow deviation;

[0036] The absolute value of the flow deviation is compared with the deviation dead zone threshold: if the absolute value of the flow deviation is less than or equal to the deviation dead zone threshold, no adjustment is required; if the absolute value of the flow deviation is greater than the deviation dead zone threshold and the flow deviation is positive, the set flow of the fine-tuning flow meter is reduced by one adjustment step; if the absolute value of the flow deviation is greater than the deviation dead zone threshold and the flow deviation is negative, the set flow of the fine-tuning flow meter is increased by one adjustment step.

[0037] After each fine-tuning of the flow meter's set flow rate is completed, the flow sampling, filtering, flow deviation calculation, and comparison adjustment process is automatically repeated until the absolute value of the flow deviation is always less than or equal to the deviation dead zone threshold. At this point, the flow compensation is considered complete, and the fine-tuning flow meter is kept at the current set flow rate.

[0038] Optionally, the step of performing low-temperature plasma treatment on the cooled blank using the plasma processing device to obtain the target bio-based biodegradable printing material includes:

[0039] The cooled billet is completely immersed in anhydrous ethanol for ultrasonic cleaning to obtain a cleaned billet. After cleaning, the cleaned billet is removed and dried until there is no liquid residue on the surface of the billet to obtain a dried billet.

[0040] The plasma processing device is confirmed to have a built-in high-voltage pulse power supply, a stainless steel electrode and a lower grounding electrode, wherein the stainless steel electrode is positioned above the lower grounding electrode.

[0041] The dried blank is laid flat on the surface of the lower grounding electrode, and the discharge voltage, processing time and oxygen flow rate of the plasma treatment device are preset.

[0042] Oxygen is introduced into the plasma processing device at the stated oxygen flow rate until the plasma processing device is filled with oxygen.

[0043] The high-voltage pulse power supply is started with the discharge voltage value to cause the oxygen between the stainless steel electrode and the lower ground electrode to break down and discharge. The duration of the breakdown discharge is then timed, and the dried billet is subjected to low-temperature plasma treatment.

[0044] When the duration of the breakdown discharge reaches the set processing time value, the high-voltage pulse power supply is turned off, the discharge is stopped, and the dried blank material after low-temperature plasma treatment is taken out to obtain the target bio-based biodegradable printing material.

[0045] Optionally, the step of completely immersing the cooled billet in anhydrous ethanol for ultrasonic cleaning to obtain a cleaned billet includes:

[0046] Place the cooled billets in a single layer, without stacking or sticking together, into the cleaning container, and add anhydrous ethanol to the cleaning container to completely immerse the cooled billets in the anhydrous ethanol.

[0047] The ultrasonic frequency, cleaning temperature, and cleaning time of the ultrasonic cleaning device are set according to the cooled blank material.

[0048] Start the ultrasonic cleaning device and perform ultrasonic cleaning on the cooled billet according to the set cleaning temperature and ultrasonic frequency values. Continue cleaning according to the cleaning time value. After cleaning is completed, a cleaned billet is obtained.

[0049] Remove the preform that was cleaned once, pour out the anhydrous ethanol from the cleaning container, clean the cleaning container, refill with anhydrous ethanol, completely immerse the preform that was cleaned once again, and repeat the ultrasonic cleaning process to obtain the preform that was cleaned twice.

[0050] Take out the secondary cleaned billet and rinse it with anhydrous ethanol. After rinsing, the cleaned billet is obtained.

[0051] Optionally, the step of activating the high-voltage pulse power supply with the discharge voltage value to cause oxygen breakdown discharge between the stainless steel electrode and the lower grounding electrode includes:

[0052] Confirm the high-voltage pulse power supply, and set the discharge voltage threshold and target discharge current of the high-voltage pulse power supply;

[0053] Start the high-voltage pulse power supply, measure the power output voltage of the high-voltage pulse power supply, and boost the power output voltage. At the same time, collect the real-time gap voltage between the stainless steel electrode and the lower grounding electrode.

[0054] When the real-time gap voltage reaches the discharge voltage threshold, the oxygen between the stainless steel electrode and the lower ground electrode undergoes initial ionization and breakdown, generating a discharge current, and the real-time current value of the discharge current is read.

[0055] The difference between the real-time current value and the target discharge current is calculated to obtain the current deviation value;

[0056] Determine the sign of the current deviation value. If the current deviation value is negative, continue to increase the output voltage of the high-voltage pulse power supply to increase the real-time current value.

[0057] If the current deviation value is positive, then the output voltage of the high-voltage pulse power supply is reduced to decrease the real-time current value.

[0058] After each voltage adjustment is completed, the above-mentioned real-time current value reading, current deviation value calculation and output voltage adjustment actions are repeated until the absolute value of the current deviation value is less than the preset current deviation threshold.

[0059] Optionally, starting the high-voltage pulse power supply, measuring the power output voltage of the high-voltage pulse power supply, and boosting the power output voltage includes:

[0060] Set the boost step size and maximum number of iterations, read the current output voltage of the high-voltage pulse power supply, and record the current output voltage as the initial voltage;

[0061] Starting from the initial voltage, the voltage boosting action is performed sequentially, increasing the power supply output voltage by one boosting step each time. After a single boost is completed, the real-time voltage value of the power supply output voltage is re-acquired, and the number of boosts is accumulated.

[0062] Determine whether the real-time voltage value has reached the discharge voltage threshold. If the real-time voltage value reaches or exceeds the discharge voltage threshold, stop the voltage boosting operation, accumulate the number of voltage boosting times, and complete the increase of the power supply output voltage.

[0063] If the cumulative number of voltage boosts reaches the maximum number of iterations and the real-time voltage value still does not reach the discharge voltage threshold, the voltage boosting operation will be stopped and an alarm will be issued.

[0064] If the real-time voltage value reaches or exceeds the discharge voltage threshold, the boost operation is stopped, and the power supply output voltage is raised.

[0065] To achieve the above objectives, the present invention also provides a bio-based biodegradable printing material and its preparation system, comprising:

[0066] The system confirms the material preparation module, which is used to receive printing material preparation instructions and confirm the printing material production system according to the printing material preparation instructions. The printing material production system includes: a material conveying device, an esterification reaction device, a gas conduction device, a melt polycondensation device, a particle cutting device, a vacuum drying device, a hot pressing device, and a plasma treatment device. The esterification reaction device consists of an inlet end, a reaction end, and an exhaust end. It obtains bio-based raw materials and uses the material conveying device to transport the bio-based raw materials to the reaction end.

[0067] An esterification reaction control module is used to set a water volume threshold, introduce nitrogen into the gas inlet using the gas conduction device, adjust the nitrogen flow rate in real time by monitoring the exhaust end, heat the bio-based raw material at the reaction end and carry out the esterification reaction, monitor the water volume generated by the esterification reaction device in real time, and stop the esterification reaction when the water volume generated reaches the set water volume threshold to obtain the esterification product.

[0068] The polycondensation reaction management module is used to transport the esterification product to the melt polycondensation device, set the target vacuum degree and target torque value, continue to heat the esterification product in the melt polycondensation device and perform vacuum treatment, monitor the vacuum degree in the melt polycondensation device in real time, when the vacuum degree reaches the set target vacuum degree, stir the esterification product and carry out the melt polycondensation reaction, and monitor the stirring torque during the stirring process. When the stirring torque reaches the set target torque value, stop heating, stirring and melt polycondensation reaction to obtain molten copolyester;

[0069] The molding and drying module is used to cool and solidify molten copolyester. The cooled and solidified molten copolyester is cut into copolyester particles using the particle cutting device. The copolyester particles are then vacuum dried using the vacuum drying device to obtain dried copolyester particles. The dried copolyester particles are then preheated, pressure-held, and cooled using the hot pressing molding device to obtain a cooled blank. The cooled blank is then subjected to low-temperature plasma treatment using the plasma treatment device to obtain the target bio-based biodegradable printing material.

[0070] To address the above problems, the present invention also provides an electronic device, the electronic device comprising:

[0071] Memory, storing at least one instruction;

[0072] The processor executes the instructions stored in the memory to realize the bio-based biodegradable printing material and its preparation method described above.

[0073] To address the aforementioned problems, the present invention also provides a computer-readable storage medium storing at least one instruction, which is executed by a processor in an electronic device to implement the bio-based biodegradable printing material and its preparation method described above.

[0074] To address the problems described in the background art, this invention first receives a printing material preparation instruction and confirms a printing material production system based on this instruction. This system includes a material conveying device, an esterification reaction device, a gas conduction device, a melt polycondensation device, a particle cutting device, a vacuum drying device, a hot pressing device, and a plasma treatment device. The esterification reaction device consists of an inlet, a reaction end, and an exhaust end. Bio-based raw materials are obtained, and the material conveying device transports these materials to the reaction end. This invention addresses the issue that traditional bio-based printing material preparation relies on manual, step-by-step operations with a lack of unified start-up timing between devices. Therefore, it uses a unified instruction to confirm an integrated production system, enabling automatic delivery of raw materials to the reaction end. Next, a water volume threshold is set. Nitrogen gas is introduced into the inlet using the gas conduction device. The nitrogen flow rate is adjusted in real-time by monitoring the exhaust end. This heats the bio-based raw materials at the reaction end and initiates an esterification reaction. The amount of water generated in the esterification reaction device is monitored in real-time. When the generated water volume reaches the set threshold, the esterification reaction is stopped, yielding the esterified product. As can be seen, this invention addresses the problem that traditional esterification reaction endpoints often rely on empirical time or acid value detection, which can easily lead to incomplete reactions or increased side reactions. Therefore, by real-time monitoring of the generated water volume and comparing it with a preset threshold, the endpoint of the esterification reaction can be accurately and automatically determined. Simultaneously, a gas conduction device dynamically adjusts the nitrogen flow rate to create an oxygen-free environment and prevent raw material oxidation. The esterified product is then transported to a melt polycondensation device, where a target vacuum level and target torque value are set. The esterified product in the melt polycondensation device is continuously heated while undergoing vacuum treatment. The vacuum level in the melt polycondensation device is monitored in real time. When the vacuum level reaches the set target vacuum level, the esterified product is stirred and undergoes a melt polycondensation reaction, while the stirring torque is monitored. When the stirring torque reaches the set target torque value, heating, stirring, and the melt polycondensation reaction are stopped, resulting in a molten copolyester. As can be seen, this invention addresses the problems of traditional polycondensation reaction endpoint control relying heavily on offline viscosity sampling and measurement, which is cumbersome, has a slow response, and suffers from wide molecular weight distribution due to vacuum fluctuations. Therefore, it first uses achieving the target vacuum level as the trigger condition for initiating stirring and reaction, and then uses reaching the target stirring torque as the criterion for determining the reaction endpoint. This achieves closed-loop precise control of the polycondensation reaction endpoint, thereby obtaining molten copolyester with stable molecular weight and high batch consistency. Finally, the molten copolyester is cooled and solidified. The solidified molten copolyester is then cut into copolyester particles using the particle cutting device. The particles are then vacuum dried using the vacuum drying device to obtain dried copolyester particles. The dried copolyester particles are then preheated, pressure-held, and cooled sequentially using the hot pressing device to obtain a cooled blank. Finally, the cooled blank is subjected to low-temperature plasma treatment using the plasma treatment device to obtain the target bio-based biodegradable printing material.As can be seen, this invention takes into account that molten copolyester, after cooling, forms irregular lumps, and direct hot pressing easily produces bubbles and uneven thickness. Traditional bio-based printing materials have low surface polarity and poor hydrophilicity, and conventional corona treatment suffers from uneven strength and rapid effect decay. Therefore, this invention first cuts the material into uniform particles and vacuum-dries them, then hot-presses them to obtain a flat and dense blank. Finally, a plasma treatment device is used to generate uniform and stable low-temperature plasma in an oxygen atmosphere to chemically modify and microscopically roughen the surface of the blank, significantly improving surface wettability and ink adhesion without affecting the material's biodegradability and mechanical strength, thus achieving synergistic optimization of the overall performance of the printing material. Therefore, this invention can achieve efficient and stable preparation of bio-based biodegradable printing materials, significantly improving the material's printability and surface hydrophilicity while maintaining excellent biodegradability and mechanical strength. Attached Figure Description

[0075] Figure 1 A schematic flowchart illustrating a bio-based biodegradable printing material and its preparation method according to an embodiment of the present invention;

[0076] Figure 2 A functional block diagram of a bio-based biodegradable printing material and its preparation system provided in an embodiment of the present invention;

[0077] Figure 3 This is a schematic diagram of the structure of an electronic device that implements the bio-based biodegradable printing material and its preparation method, according to an embodiment of the present invention.

[0078] Explanation of reference numerals in the attached figures:

[0079] 10. Electronic device; 11. Processor; 12. Memory; 13. Bus.

[0080] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0081] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0082] This application provides a bio-based biodegradable printing material and its preparation method. The execution entity of the bio-based biodegradable printing material and its preparation method includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the bio-based biodegradable printing material and its preparation method can be executed by software or hardware installed on a terminal device or a server device, and the software can be a blockchain platform. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster.

[0083] Reference Figure 1 The diagram shown is a schematic flowchart of a bio-based biodegradable printing material and its preparation method according to an embodiment of the present invention. In this embodiment, the bio-based biodegradable printing material and its preparation method include:

[0084] S1. Receive printing material preparation instructions, and confirm the printing material production system according to the printing material preparation instructions. The printing material production system includes: a material conveying device, an esterification reaction device, a gas conduction device, a melt polycondensation device, a particle cutting device, a vacuum drying device, a hot pressing device, and a plasma treatment device. The esterification reaction device consists of an inlet end, a reaction end, and an exhaust end.

[0085] It is understood that the bio-based biodegradable printing material comprises: a bio-based biodegradable copolyester as the core matrix component, accounting for 85% to 95%, and processing and printing functional aids accounting for 5% to 15%, wherein the processing and printing functional aids are composed of nucleating agents, bio-based plasticizers, opening anti-blocking agents, heat-stabilizing antioxidants, and compatibilizers.

[0086] It should be explained that the preparation instructions are digital control signals issued by operators at the printing materials production plant through the human-machine interface of the central control console. The printing materials production system is a collection of hardware equipment that executes the entire preparation process, including material conveying devices, esterification reaction devices, gas conduction devices, melt polycondensation devices, particle cutting devices, vacuum drying devices, hot pressing devices, and plasma treatment devices. The system includes a material conveying device for automatically transporting materials between various process units, which can work with the system to achieve quantitative feeding; an esterification reaction unit for causing esterification of bio-based raw materials and generating esterification products; a gas conduction device for introducing nitrogen into the esterification reaction unit to remove oxygen, and for precisely controlling the flow rate of nitrogen during the introduction process; a melt polycondensation unit, which is the next step after the esterification reaction, with a built-in automatic stirring mechanism and torque monitoring module, for further polycondensing the esterification products into molten copolyester; a particle cutting device for cutting the cooled and solidified copolyester into copolyester particles; a vacuum drying device for removing residual moisture adsorbed on the surface and inside of the particles; a hot pressing forming device for preheating, pressurizing, and cooling the dried copolyester particles to obtain sheet-like cooled blanks; and a plasma treatment device for performing low-temperature plasma composite modification and optimization on the surface of the blanks to improve their printability.

[0087] Furthermore, the esterification reaction device consists of an inlet end, a reaction end, and an exhaust end. The inlet end is located on one side of the esterification reaction device cavity and is the only channel for nitrogen to enter the esterification reaction device. The reaction end receives the bio-based raw materials transferred by the material conveying device and is the main chamber containing the bio-based raw materials and carrying out the esterification reaction. It is equipped with a stirrer, a heating jacket, and a temperature sensor. The exhaust end is located at a higher position on the opposite side of the esterification reaction device cavity, away from the inlet end. It discharges the original air, the nitrogen-air mixture, and the water vapor generated during the reaction process from the cavity. An oxygen sensor is fixedly installed on the outside of the exhaust end to monitor the oxygen content in the discharged gas in real time.

[0088] S2. Obtain bio-based raw materials and use the material conveying device to transport the bio-based raw materials to the reaction end.

[0089] It should be explained that bio-based raw materials are organic compounds derived from renewable biomass resources. They are mainly composed of bio-based dicarboxylic acids containing carboxyl groups and bio-based diols containing hydroxyl groups. Typical raw materials include succinic acid and 1,4-butanediol. The bio-based raw materials undergo esterification and melt polycondensation reactions sequentially to prepare aliphatic polyester substrates. These aliphatic polyesters possess good biodegradability due to the presence of easily hydrolyzed ester bonds in their molecular chains.

[0090] Understandably, the material conveying device adopts a closed conveying structure, which can prevent the raw materials from being oxidized, absorbing moisture, or mixed with impurities when exposed to the outside air during the transfer process. It is also necessary to ensure that the reaction end is clean and dry in advance, and that the internal temperature is stable within the preset initial reaction temperature range, so as to avoid the bio-based raw materials from clumping or local overheating due to temperature fluctuations after entering the reaction end. Then, the bio-based raw materials are quantitatively fed into the reaction end cavity of the esterification reaction device. After the feeding is completed, the material stays in the reaction end, waiting for subsequent processes such as nitrogen gas introduction and heating to start the esterification reaction.

[0091] S3. Set a water volume threshold, introduce nitrogen into the gas inlet using the gas conduction device, adjust the nitrogen flow rate in real time by monitoring the exhaust end, heat the bio-based raw material at the reaction end and carry out the esterification reaction, monitor the water volume generated by the esterification reaction device in real time, and stop the esterification reaction when the water volume generated reaches the set water volume threshold to obtain the esterification product.

[0092] It should be explained that the water volume threshold is a manually set criterion for terminating the esterification reaction. It refers to the target value of the theoretically generated water volume at the end of the esterification reaction, used to determine whether the esterification reaction has reached the expected conversion degree. The flow rate is the volumetric flow rate of nitrogen passing through the nitrogen inlet pipe per unit time, used to quantify the nitrogen inlet rate and volume. Under heating and catalysis, the carboxyl and hydroxyl groups in the bio-based raw materials undergo a classic esterification chemical reaction, forming ester bonds and releasing water molecules. The raw materials are gradually converted into low molecular weight esterified oligomers. The generated water volume can intuitively characterize the progress of the esterification reaction. When the cumulative generated water volume reaches the preset water volume threshold, it is determined that the esterification reaction has reached the preset conversion rate. The heating component at the reaction end is immediately shut off, terminating the esterification chemical reaction. At this time, the esterification product is obtained, which is a low molecular weight esterified oligomer containing unreacted terminal hydroxyl and terminal carboxyl groups, used as a raw material for subsequent melt polycondensation reactions.

[0093] Furthermore, the step of introducing nitrogen gas into the inlet using the gas conduction device and adjusting the nitrogen flow rate in real time by monitoring the exhaust end includes:

[0094] The gas conduction device is confirmed to include an oxygen sensor, a coarse adjustment flow meter, a fine adjustment flow meter, and a nitrogen inlet pipeline, and the gas conduction device is connected to the esterification reaction device.

[0095] Initialize the oxygen sensor and use the oxygen sensor to collect the oxygen content monitoring value at the exhaust end of the esterification reaction device in real time;

[0096] Set a replacement completion threshold and a target oxygen content threshold, wherein the replacement completion threshold is lower than the target oxygen content threshold;

[0097] The gas phase space volume of the esterification reaction apparatus and the required reaction temperature of the esterification reaction are obtained. The first nitrogen flow rate is calculated based on the gas phase space volume and the required reaction temperature. The coarse adjustment target flow rate is set based on the first nitrogen flow rate, wherein the coarse adjustment target flow rate is less than the first nitrogen flow rate.

[0098] The coarse adjustment flow meter and the fine adjustment flow meter are integrated in series in the nitrogen inlet pipeline. The coarse adjustment flow meter is turned on to adjust the nitrogen flow rate to the coarse adjustment target flow rate. Then, the flow rate is compensated by the fine adjustment flow meter to compensate the nitrogen flow rate to the first nitrogen flow rate. The first nitrogen flow rate is used to replace the air in the esterification reaction device.

[0099] Set a second nitrogen flow rate, wherein the second nitrogen flow rate is less than the first nitrogen flow rate. Compare the oxygen content monitoring value with the set replacement completion threshold in real time. When the oxygen content monitoring value is continuously lower than the replacement completion threshold, turn off the coarse adjustment flow meter and use the fine adjustment flow meter to switch the nitrogen flow rate to be maintained at the second nitrogen flow rate.

[0100] Nitrogen gas is continuously introduced into the inlet at the second nitrogen flow rate until the esterification reaction experiment is completed.

[0101] It should be explained that the oxygen sensor is an electrochemical gas detection element, assembled at the exhaust end of the esterification reaction device, used to measure the oxygen content in the exhaust gas in real time, determining whether the oxygen in the esterification reaction device has been sufficiently replaced by nitrogen. A coarse-adjustment flow meter and a fine-adjustment flow meter are connected in series in the same nitrogen pipeline. The coarse-adjustment flow meter is an electromagnetic flow regulating valve with a large adjustment range, used to quickly adjust the nitrogen flow rate to near the coarse-adjustment target flow rate; its response speed is fast, but its adjustment accuracy is low. The fine-adjustment flow meter is connected in series after the coarse-adjustment flow meter, used to finely compensate the nitrogen flow rate after coarse adjustment, ensuring the flow rate accurately reaches the first nitrogen flow rate. The nitrogen inlet pipeline refers to the sealed pipe connecting the nitrogen source, flow meter, and inlet end, connected to the inlet end of the esterification reaction device, responsible for supplying nitrogen into the device.

[0102] Understandably, the replacement completion threshold is a preset oxygen content percentage value. When the oxygen content monitoring value at the exhaust end is lower than this threshold, it indicates that the air in the esterification reaction device has been basically replaced. The target oxygen content threshold is a preset upper limit value of oxygen content, which is the maximum oxygen content allowed for the entire esterification reaction. As long as the internal oxygen content does not exceed this value, it can be ensured that the material is not oxidized, and the replacement completion threshold is lower than the target oxygen content threshold. The first nitrogen flow rate refers to the target nitrogen flow rate required in the high-flow-rate replacement stage. Its function is to quickly flush and expel the original air in the device, shortening the replacement time. In addition, the first nitrogen flow rate is obtained by converting the gas phase space volume into temperature and replacement ratio using the ideal gas law and Charles's law. This is existing technology and will not be elaborated here. The coarse adjustment target flow rate is a manually set transition flow rate, which is less than the first nitrogen flow rate. It is also the initial adjustment target of the coarse adjustment flow meter to prevent the coarse adjustment flow meter from overshooting due to excessive opening at one time. This invention employs a coarse-adjustment flow meter to initially adjust the nitrogen flow rate in the pipeline to the coarse-adjustment target flow rate. Then, a fine-adjustment flow meter is activated to precisely compensate for the flow rate difference, continuously entraining air from the device and expelling it from the exhaust end, gradually reducing the internal oxygen content. The goal is to stabilize the actual pipeline flow rate at the first nitrogen flow rate. The flow compensation process involves the fine-adjustment flow meter dynamically increasing or decreasing its opening based on the deviation between the actual flow rate and the first nitrogen flow rate using a closed-loop adjustment algorithm, ensuring the total flow rate is precisely stabilized at the first nitrogen flow rate. The second nitrogen flow rate is a maintenance flow rate lower than the first nitrogen flow rate, used to continuously supply nitrogen after the purging process to maintain a slight positive pressure inside the device and prevent backflow of external air. When the oxygen content monitoring value at the exhaust end meets the standard, the air purging process is considered complete. At this point, the coarse-adjustment flow meter is turned off, leaving only the fine-adjustment flow meter operational, and the pipeline flow rate is switched and stabilized at the second nitrogen flow rate.

[0103] Furthermore, the initialization of the oxygen sensor, and the real-time acquisition of oxygen content monitoring values ​​at the exhaust end of the esterification reaction device using the oxygen sensor, includes:

[0104] To verify the oxygen sensor, introduce oxygen-free calibration nitrogen gas with a purity ≥99.99% into the oxygen sensor. Once the output value of the oxygen sensor stabilizes, read the output value of the oxygen sensor at this time as the zero-point output value.

[0105] Standard air is switched to the oxygen sensor, wherein the oxygen content of the standard air is known. When the output value of the oxygen sensor stabilizes, the output value of the oxygen sensor at this time is read as the range output value.

[0106] Based on the zero-point output value, the range output value, and the known oxygen content of the standard air, a linear correspondence between the output value of the oxygen sensor and the oxygen content is established through a linear fitting algorithm.

[0107] set up For each set of temperature values, the fitted relationship between the output value of the oxygen sensor and the oxygen content is obtained. Based on the fitted relationship, a temperature compensation function is further fitted to obtain the temperature compensation function.

[0108] During the esterification reaction, the output value of the oxygen sensor is continuously collected, and the real-time gas temperature at the exhaust end of the esterification reaction device is obtained. The real-time gas temperature is substituted into the temperature compensation function to calculate the temperature compensation coefficient.

[0109] The output value of the oxygen sensor is multiplied by the temperature compensation coefficient to obtain the real-time compensation output value. The real-time compensation output value is then substituted into the linear correspondence to convert the oxygen content monitoring value, thus completing the real-time oxygen content detection.

[0110] Understandably, the zero-point output value refers to the output electrical signal value of the oxygen sensor under oxygen-free calibration nitrogen conditions, serving as the reference point for subsequent linear correlation. The standard air refers to dry air with a known oxygen content, typically ordinary atmospheric air with an oxygen content of 20.9% or a prepared standard gas, used to calibrate the range output value of the oxygen sensor. The range output value refers to the output electrical signal value of the oxygen sensor under standard air conditions, serving as another reference point for linear correlation.

[0111] It should be explained that, using the two sets of data—0% oxygen content corresponding to the zero-point output value and standard air oxygen content corresponding to the range output value—as samples, a linear fitting algorithm is employed to construct a linear mathematical model between the output electrical signal of the oxygen sensor and the actual oxygen content of the gas. This yields a linear mapping relationship between the oxygen sensor output value and the oxygen content, used to convert any oxygen sensor output value in subsequent measurements into the corresponding oxygen content percentage. Multiple temperature gradients are then manually set, and at each constant temperature, the oxygen content and corresponding output value tests are repeated. Based on the temperature sample data obtained from all tests, a temperature compensation function is fitted. Since esterification is a high-temperature reaction, the exhaust gas temperature changes significantly. Therefore, the temperature compensation function describes the pattern of oxygen sensor output value change with temperature, used to calculate the temperature compensation coefficient based on the current real-time gas temperature, and corrects the oxygen sensor output value to correct temperature-induced errors, thereby improving the accuracy of oxygen content monitoring values ​​at different temperatures.

[0112] Furthermore, the aforementioned settings For each set of temperature values, the fitted relationship between the oxygen sensor output value and the oxygen content is obtained. Based on the fitted relationship, a temperature compensation function is further fitted, including:

[0113] Record the output value of the oxygen sensor for each set of temperature values, and take the natural logarithm of the output value of the oxygen sensor for each set of temperature values;

[0114] The temperature value and the output value after taking the natural logarithm were linearly fitted using the least squares method, and the fitting coefficient was calculated according to the following formula:

[0115] ;

[0116] in, The number of temperature value groups. For each group of temperature values, The output value of the oxygen sensor for each set of temperature values. and These are the fitting coefficients;

[0117] According to the fitting coefficients and The temperature compensation function is constructed. ,in, This is the temperature compensation coefficient.

[0118] It should be explained that the fitting coefficients and These are two parameters that describe the mathematical relationship between the temperature value and the oxygen sensor output value, where This represents the intercept of the fitted line on the ordinate. The slope of the fitted straight line and the slope together determine the specific form of the temperature compensation function. The temperature compensation function... It is composed of the fitting coefficients and The constructed exponential function takes temperature values ​​as input. The output is a compensation output value, which is used to calculate the corresponding temperature compensation value based on the current real-time gas temperature, thereby correcting the drift of the oxygen sensor output caused by temperature changes.

[0119] Furthermore, the flow compensation process performed by the fine-tuning flow meter to compensate the nitrogen flow rate to the first nitrogen flow rate includes:

[0120] Multiple instantaneous flow rates of nitrogen in the nitrogen inlet pipeline are continuously collected, and the instantaneous flow rates are processed by moving average filtering to obtain a unique actual flow rate value after filtering.

[0121] Set the deviation dead zone threshold and adjustment step size, and calculate the difference between the actual flow rate and the first nitrogen flow rate to obtain the flow deviation;

[0122] The absolute value of the flow deviation is compared with the deviation dead zone threshold: if the absolute value of the flow deviation is less than or equal to the deviation dead zone threshold, no adjustment is required; if the absolute value of the flow deviation is greater than the deviation dead zone threshold and the flow deviation is positive, the set flow of the fine-tuning flow meter is reduced by one adjustment step; if the absolute value of the flow deviation is greater than the deviation dead zone threshold and the flow deviation is negative, the set flow of the fine-tuning flow meter is increased by one adjustment step.

[0123] After each fine-tuning of the flow meter's set flow rate is completed, the flow sampling, filtering, flow deviation calculation, and comparison adjustment process is automatically repeated until the absolute value of the flow deviation is always less than or equal to the deviation dead zone threshold. At this point, the flow compensation is considered complete, and the fine-tuning flow meter is kept at the current set flow rate.

[0124] It should be explained that the nitrogen gas in the pipeline may be affected by airflow pulsations, pressure fluctuations, and equipment vibrations, resulting in high-frequency random fluctuations in the collected instantaneous flow rate values. These values ​​cannot be directly used as a basis for adjustment. Therefore, a moving average filter is used to eliminate random noise and instantaneous fluctuations, outputting a single, stable actual flow rate value that represents the current true operating condition of the pipeline. This actual flow rate value reflects the true level of the current nitrogen flow and is used as a feedback quantity for flow compensation.

[0125] Understandably, the deviation dead zone threshold is a preset positive number used to define an allowable flow error range. When the absolute value of the deviation between the actual flow rate and the first nitrogen flow rate is less than or equal to this threshold, the flow rate is considered to meet the requirements and no adjustment is needed. The adjustment step size is a preset flow adjustment amount, referring to the fixed flow rate value that is increased or decreased each time the fine-tuning flow meter is adjusted, used to control the fineness of the adjustment and the response speed. It should be explained that after each set flow rate adjustment is completed, the flow sampling, filtering, flow deviation calculation, and comparison adjustment process are repeatedly executed to continuously reduce the flow deviation, allowing the actual flow rate to gradually approach the target first nitrogen flow rate. After several adjustments, the absolute value of the flow deviation is continuously less than or equal to the deviation dead zone threshold. At this time, the set flow rate of the fine-tuning flow meter no longer changes, the nitrogen flow rate has been accurately stabilized near the first nitrogen flow rate, and the pipeline continues to carry out the air replacement process with a stable first nitrogen flow rate. At this time, the flow compensation is completed.

[0126] S4. The esterification product is transported to the melt polycondensation device. The target vacuum degree and target torque value are set. The esterification product in the melt polycondensation device is heated and vacuum treatment is performed. The vacuum degree in the melt polycondensation device is monitored in real time. When the vacuum degree reaches the set target vacuum degree, the esterification product is stirred and melt polycondensation reaction is carried out. At the same time, the stirring torque during the stirring process is monitored. When the stirring torque reaches the set target torque value, the heating, stirring and melt polycondensation reaction are stopped to obtain molten copolyester.

[0127] It should be explained that the esterification product at this stage is a low-molecular-weight esterified oligomer, formed through dehydration in the esterification reaction. It is then conveyed in a closed system to the melt polycondensation unit via a material conveying device, awaiting further melt polycondensation. The target vacuum level is a preset pressure value, referring to the absolute pressure value required within the melt polycondensation unit. It characterizes the vacuum level inside the unit, providing a low-pressure environment to promote the removal of small-molecule byproducts. The target torque value is a preset torque value, referring to the target stirring torque value required by the stirrer during the melt polycondensation reaction. It characterizes the viscosity of the molten copolyester at the reaction endpoint. The vacuum level is a real-time measured pressure data point, referring to the current absolute pressure value inside the melt polycondensation unit, used to determine whether the target vacuum level has been reached. The melt polycondensation reaction refers to the process of processing the esterification product into a high-molecular-weight polyester to obtain a molten copolyester under high temperature, high vacuum, and stirring conditions. During this process, the hydroxyl and carboxyl groups at both ends of the esterified oligomer molecular chains undergo intermolecular dehydration condensation again, and a large number of oligomers connect to each other, gradually forming a long-chain high-molecular-weight copolyester. If stirring is started before the vacuum level is reached, residual air will be introduced, disrupting the vacuum environment. This will not only fail to effectively remove small molecules but will also exacerbate the oxidation of the material. Therefore, this invention stipulates that stirring can only be started when the vacuum level is reached.

[0128] It should be explained that the stirring torque is the torque required for the stirrer to overcome the viscous resistance of the molten material during rotation. As the melt polycondensation reaction proceeds, the molecular weight of the polymer gradually increases, the melt viscosity rises, and the stirring torque also increases accordingly. When the stirring torque reaches the preset target torque value, it indicates that the molecular weight of the molten copolyester has reached the expected requirement, and the reaction can be terminated. The molten copolyester refers to a high-molecular-weight bio-based copolyester obtained after the melt polycondensation reaction, which is in a high-temperature molten state and has biodegradable properties, providing raw materials for subsequent granulation and hot pressing.

[0129] S5. Cool and solidify the molten copolyester, cut the cooled and solidified molten copolyester into copolyester particles using the particle cutting device, and then perform vacuum drying treatment on the copolyester particles using the vacuum drying device to obtain dried copolyester particles.

[0130] It should be explained that the cooling and solidification process involves cooling the copolyester from a high-temperature molten state below its melting point, transforming it from a liquid to a solid state. This process yields solid block materials with a certain degree of hardness and brittleness, facilitating subsequent cutting operations. The copolyester particles refer to solid granular copolyester particles with a specific particle size range obtained after being cut by a particle cutting device. The vacuum drying process involves placing the copolyester particles in a vacuum drying device and maintaining them at a preset drying temperature and vacuum level for a certain period of time. This process removes moisture from the copolyester particles due to water absorption or residual reaction byproducts. The dried copolyester particles refer to copolyester particles that have undergone vacuum drying, exhibiting good thermal stability and processing fluidity, and are used as raw materials for subsequent hot pressing to prepare blanks.

[0131] S6. The dried copolyester particles are preheated, pressure-held and cooled sequentially using the hot pressing molding device to obtain a cooled blank. The cooled blank is then subjected to low-temperature plasma treatment using the plasma treatment device to obtain the target bio-based biodegradable printing material.

[0132] It should be explained that the preheating and pressure holding operation includes two consecutive stages: the preheating stage is to heat the mold and the internal copolyester particles to a preset molding temperature so that the copolyester particles melt and fill the entire cavity; the pressure holding stage is to apply a preset pressure to the mold after preheating and continue for a certain period of time to make the molten copolyester flow evenly in the cavity, remove air bubbles and form a dense structure.

[0133] Understandably, the cooling operation is the process of lowering the mold temperature below the glass transition temperature of the copolyester by circulating cooling water or natural cooling after the pressure holding period, used to solidify and shape the molten copolyester, maintaining the shape and dimensional stability imparted by the mold. The low-temperature plasma treatment is a process of generating low-temperature plasma in an oxygen or air atmosphere using a plasma treatment device to bombard and modify the surface of the cooled blank. The target bio-based biodegradable printing material refers to the final product whose surface properties meet printing requirements after low-temperature plasma treatment. It can be completely degraded into carbon dioxide and water under the action of microorganisms in the natural environment, while possessing good print clarity, abrasion resistance, and water resistance, making it suitable for environmentally friendly packaging, labels, and green printing.

[0134] Furthermore, the process of performing low-temperature plasma treatment on the cooled blank using the plasma processing device to obtain the target bio-based biodegradable printing material includes:

[0135] The cooled billet is completely immersed in anhydrous ethanol for ultrasonic cleaning to obtain a cleaned billet. After cleaning, the cleaned billet is removed and dried until there is no liquid residue on the surface of the billet to obtain a dried billet.

[0136] The plasma processing device is confirmed to have a built-in high-voltage pulse power supply, a stainless steel electrode and a lower grounding electrode, wherein the stainless steel electrode is positioned above the lower grounding electrode.

[0137] The dried blank is laid flat on the surface of the lower grounding electrode, and the discharge voltage, processing time and oxygen flow rate of the plasma treatment device are preset.

[0138] Oxygen is introduced into the plasma processing device at the stated oxygen flow rate until the plasma processing device is filled with oxygen.

[0139] The high-voltage pulse power supply is started with the discharge voltage value to cause the oxygen between the stainless steel electrode and the lower ground electrode to break down and discharge. The duration of the breakdown discharge is then timed, and the dried billet is subjected to low-temperature plasma treatment.

[0140] When the duration of the breakdown discharge reaches the set processing time value, the high-voltage pulse power supply is turned off, the discharge is stopped, and the dried blank material after low-temperature plasma treatment is taken out to obtain the target bio-based biodegradable printing material.

[0141] It should be explained that the high-voltage pulse power supply is a power electronic device capable of outputting high-frequency, high-voltage pulse signals. It is used to generate a strong electric field between the stainless steel electrode and the lower grounding electrode, thereby stimulating gas breakdown discharge. The stainless steel electrode is the high-voltage end in the plasma processing device, used to form a strong electric field in the tip region, reducing the gas breakdown voltage and promoting corona discharge. The lower grounding electrode is the grounding end in the plasma processing device, used to support the dried blank and form a non-uniform electric field with the stainless steel electrode, while also serving as a counter electrode to form a discharge circuit.

[0142] Understandably, the discharge voltage value is a preset high-voltage pulse power supply output voltage value, which must be higher than the breakdown voltage threshold of the gas between the stainless steel electrode and the lower grounding electrode to ensure gas breakdown and the formation of a stable corona discharge. The processing time value refers to the duration of the low-temperature plasma treatment, used to control the degree of surface modification. After oxygen is excited by plasma, it generates active particles such as oxygen free radicals and excited-state oxygen molecules. Active oxygen generates polar oxygen-containing functional groups such as hydroxyl and carboxyl groups on the surface of the polyester preform, significantly improving the surface properties of the material and strengthening ink adhesion. Therefore, oxygen is selected as the working gas in this invention. The oxygen flow rate value is a preset volume of oxygen introduced into the ion treatment device per unit time, used to ensure that there is a sufficient concentration of oxygen in the reaction chamber of the device to generate a sufficient amount of active particles.

[0143] Furthermore, the breakdown discharge refers to the phenomenon where, when the voltage between the stainless steel electrode and the lower grounding electrode exceeds the breakdown threshold of the gas medium, the gas is ionized to form a conductive channel and generate current, which is used to generate low-temperature plasma. The low-temperature plasma treatment refers to the process of bombarding and chemically modifying the surface of the dried blank using plasma generated by the breakdown discharge. The dried blank after low-temperature plasma treatment is a blank with completed surface modification; this blank is the target bio-based biodegradable printing material, and its surface properties have met printing requirements, making it directly usable in subsequent printing processes.

[0144] Furthermore, the step of completely immersing the cooled billet in anhydrous ethanol for ultrasonic cleaning to obtain a cleaned billet includes:

[0145] Place the cooled billets in a single layer, without stacking or sticking together, into the cleaning container, and add anhydrous ethanol to the cleaning container to completely immerse the cooled billets in the anhydrous ethanol.

[0146] The ultrasonic frequency, cleaning temperature, and cleaning time of the ultrasonic cleaning device are set according to the cooled blank material.

[0147] Start the ultrasonic cleaning device and perform ultrasonic cleaning on the cooled billet according to the set cleaning temperature and ultrasonic frequency values. Continue cleaning according to the cleaning time value. After cleaning is completed, a cleaned billet is obtained.

[0148] Remove the preform that was cleaned once, pour out the anhydrous ethanol from the cleaning container, clean the cleaning container, refill with anhydrous ethanol, completely immerse the preform that was cleaned once again, and repeat the ultrasonic cleaning process to obtain the preform that was cleaned twice.

[0149] Take out the secondary cleaned billet and rinse it with anhydrous ethanol. After rinsing, the cleaned billet is obtained.

[0150] Understandably, this invention employs a combined process of two-stage immersion ultrasonic cleaning and anhydrous ethanol spray rinsing. This process can remove impurities adhering to the surface of the preform after hot pressing layer by layer, avoiding the problems of incomplete cleaning and secondary contamination caused by solvent contamination by impurities in a single cleaning. Only when the cleaned preform meets the required cleanliness standards can the subsequent low-temperature plasma discharge be stable, the surface modification uniform, and ultimately the adhesion of the printed material be guaranteed.

[0151] Furthermore, the step of activating the high-voltage pulse power supply with the discharge voltage value to cause oxygen breakdown discharge between the stainless steel electrode and the lower grounding electrode includes:

[0152] Confirm the high-voltage pulse power supply, and set the discharge voltage threshold and target discharge current of the high-voltage pulse power supply;

[0153] Start the high-voltage pulse power supply, measure the power output voltage of the high-voltage pulse power supply, and boost the power output voltage. At the same time, collect the real-time gap voltage between the stainless steel electrode and the lower grounding electrode.

[0154] When the real-time gap voltage reaches the discharge voltage threshold, the oxygen between the stainless steel electrode and the lower ground electrode undergoes initial ionization and breakdown, generating a discharge current, and the real-time current value of the discharge current is read.

[0155] The difference between the real-time current value and the target discharge current is calculated to obtain the current deviation value;

[0156] Determine the sign of the current deviation value. If the current deviation value is negative, continue to increase the output voltage of the high-voltage pulse power supply to increase the real-time current value.

[0157] If the current deviation value is positive, then the output voltage of the high-voltage pulse power supply is reduced to decrease the real-time current value.

[0158] After each voltage adjustment is completed, the above-mentioned real-time current value reading, current deviation value calculation and output voltage adjustment actions are repeated until the absolute value of the current deviation value is less than the preset current deviation threshold.

[0159] It should be explained that the discharge voltage threshold is the minimum voltage value required for initial breakdown of the gas between the stainless steel electrode and the lower grounding electrode, serving as the target voltage for the high-voltage pulse power supply's boost phase. The target discharge current is the desired current value required to maintain stable corona discharge, serving as the target value for the current closed-loop regulation phase. The real-time gap voltage refers to the measured voltage between the stainless steel electrode and the lower grounding electrode at the current moment during the high-voltage pulse power supply's boost process, used to determine whether the discharge voltage threshold, i.e., the critical condition for gas breakdown, has been reached. Applying high voltage instantaneously can easily cause a sudden change in the electric field, damaging not only the stainless steel electrode and the pulse power supply but also causing high-temperature burns to the heat-sensitive bio-based substrate. This invention employs a gradual voltage increase to smoothly establish the electric field, achieving safe ignition.

[0160] Understandably, oxygen dissociates under the influence of a high-voltage electric field, forming a plasma conductive channel. This is the initial glow discharge stage, where the discharge state is not yet stable, and the current fluctuation is large, requiring further adjustment. The discharge current refers to the measured current value in the discharge circuit at the current moment after the initial breakdown of the gas, used for comparison with the target discharge current. Under low-temperature glow discharge conditions, the higher the voltage between the electrodes, the greater the electric field strength, the higher the degree of gas ionization, and the larger the discharge current. Therefore, current negative feedback regulation is adopted. The current deviation value is the difference between the real-time current value and the target discharge current, used to quantify the direction and magnitude of the deviation between the current discharge current and the target value. The current deviation threshold is the upper limit of the allowable absolute value of the current deviation. When the absolute value of the difference between the real-time current value and the target discharge current is less than this threshold, the discharge current is considered to have stabilized near the target value, and the breakdown discharge state can be determined to be stable. Finally, a continuous and stable low-temperature glow discharge is formed between the electrodes, and the high-voltage pulse power supply startup process ends.

[0161] Furthermore, the step of activating the high-voltage pulse power supply, measuring the power output voltage of the high-voltage pulse power supply, and boosting the power output voltage includes:

[0162] Set the boost step size and maximum number of iterations, read the current output voltage of the high-voltage pulse power supply, and record the current output voltage as the initial voltage;

[0163] Starting from the initial voltage, the voltage boosting action is performed sequentially, increasing the power supply output voltage by one boosting step each time. After a single boost is completed, the real-time voltage value of the power supply output voltage is re-acquired, and the number of boosts is accumulated.

[0164] Determine whether the real-time voltage value has reached the discharge voltage threshold. If the real-time voltage value reaches or exceeds the discharge voltage threshold, stop the voltage boosting operation, accumulate the number of voltage boosting times, and complete the increase of the power supply output voltage.

[0165] If the cumulative number of voltage boosts reaches the maximum number of iterations and the real-time voltage value still does not reach the discharge voltage threshold, the voltage boosting operation will be stopped and an alarm will be issued.

[0166] If the real-time voltage value reaches or exceeds the discharge voltage threshold, the boost operation is stopped, and the power supply output voltage is raised.

[0167] It should be explained that the voltage boosting of the high-voltage pulse power supply is a pre-control step in the cryogenic plasma discharge system. A soft-start mode with a fixed voltage step size is used instead of direct high-voltage start. The purpose is to smoothly establish the electric field between the electrodes, protecting the high-voltage pulse power supply, electrodes, and the thermosensitive bio-based substrate. The boost step size refers to the fixed amplitude of the increase or decrease in output voltage during each adjustment of the high-voltage pulse power supply, used to control the precision and response speed of the boosting process. The maximum number of iterations refers to the upper limit of the allowed number of boosting adjustments, used to prevent infinite looping of the boosting process due to hardware failure or improper parameter settings. If the discharge voltage threshold is not reached when the maximum number of boosting iterations is reached, the system is considered abnormal and operation is stopped. The current output voltage refers to the output voltage value of the high-voltage pulse power supply before the start of the boosting operation, before any adjustment, serving as the starting reference value for the boosting process. The initial voltage is the same value as the current output voltage; it is named the initial voltage and used for calculating the subsequent boosting amplitude, referring to the starting voltage value of the boosting process. The boost count refers to the number of times the output voltage has been increased since the initial voltage. Each time the boost step is increased, the boost count is incremented by one. This count is used to compare with the maximum number of iterations to prevent infinite boosting.

[0168] Furthermore, when the voltage boosting count reaches the maximum iteration count, and the real-time voltage value still has not reached the discharge voltage threshold, it is determined that the system may have faults such as abnormal electrode spacing, insufficient oxygen concentration, power supply failure, or damaged line insulation. At this time, the voltage boosting is forcibly stopped and an alarm signal is output to remind manual inspection for timely repair.

[0169] To address the problems described in the background art, this invention first receives a printing material preparation instruction and confirms a printing material production system based on this instruction. This system includes a material conveying device, an esterification reaction device, a gas conduction device, a melt polycondensation device, a particle cutting device, a vacuum drying device, a hot pressing device, and a plasma treatment device. The esterification reaction device consists of an inlet, a reaction end, and an exhaust end. Bio-based raw materials are obtained, and the material conveying device transports these materials to the reaction end. This invention addresses the issue that traditional bio-based printing material preparation relies on manual, step-by-step operations with a lack of unified start-up timing between devices. Therefore, it uses a unified instruction to confirm an integrated production system, enabling automatic delivery of raw materials to the reaction end. Next, a water volume threshold is set. Nitrogen gas is introduced into the inlet using the gas conduction device. The nitrogen flow rate is adjusted in real-time by monitoring the exhaust end. This heats the bio-based raw materials at the reaction end and initiates an esterification reaction. The amount of water generated in the esterification reaction device is monitored in real-time. When the generated water volume reaches the set threshold, the esterification reaction is stopped, yielding the esterified product. As can be seen, this invention addresses the problem that traditional esterification reaction endpoints often rely on empirical time or acid value detection, which can easily lead to incomplete reactions or increased side reactions. Therefore, by real-time monitoring of the generated water volume and comparing it with a preset threshold, the endpoint of the esterification reaction can be accurately and automatically determined. Simultaneously, a gas conduction device dynamically adjusts the nitrogen flow rate to create an oxygen-free environment and prevent raw material oxidation. The esterified product is then transported to a melt polycondensation device, where a target vacuum level and target torque value are set. The esterified product in the melt polycondensation device is continuously heated while undergoing vacuum treatment. The vacuum level in the melt polycondensation device is monitored in real time. When the vacuum level reaches the set target vacuum level, the esterified product is stirred and undergoes a melt polycondensation reaction, while the stirring torque is monitored. When the stirring torque reaches the set target torque value, heating, stirring, and the melt polycondensation reaction are stopped, resulting in a molten copolyester. As can be seen, this invention addresses the problems of traditional polycondensation reaction endpoint control relying heavily on offline viscosity sampling and measurement, which is cumbersome, has a slow response, and suffers from wide molecular weight distribution due to vacuum fluctuations. Therefore, it first uses achieving the target vacuum level as the trigger condition for initiating stirring and reaction, and then uses reaching the target stirring torque as the criterion for determining the reaction endpoint. This achieves closed-loop precise control of the polycondensation reaction endpoint, thereby obtaining molten copolyester with stable molecular weight and high batch consistency. Finally, the molten copolyester is cooled and solidified. The solidified molten copolyester is then cut into copolyester particles using the particle cutting device. The particles are then vacuum dried using the vacuum drying device to obtain dried copolyester particles. The dried copolyester particles are then preheated, pressure-held, and cooled sequentially using the hot pressing device to obtain a cooled blank. Finally, the cooled blank is subjected to low-temperature plasma treatment using the plasma treatment device to obtain the target bio-based biodegradable printing material.As can be seen, this invention takes into account that molten copolyester, after cooling, forms irregular lumps, and direct hot pressing easily produces bubbles and uneven thickness. Traditional bio-based printing materials have low surface polarity and poor hydrophilicity, and conventional corona treatment suffers from uneven strength and rapid effect decay. Therefore, this invention first cuts the material into uniform particles and vacuum-dries them, then hot-presses them to obtain a flat and dense blank. Finally, a plasma treatment device is used to generate uniform and stable low-temperature plasma in an oxygen atmosphere to chemically modify and microscopically roughen the surface of the blank, significantly improving surface wettability and ink adhesion without affecting the material's biodegradability and mechanical strength, thus achieving synergistic optimization of the overall performance of the printing material. Therefore, this invention can achieve efficient and stable preparation of bio-based biodegradable printing materials, significantly improving the material's printability and surface hydrophilicity while maintaining excellent biodegradability and mechanical strength.

[0170] like Figure 2 The diagram shown is a functional block diagram of a bio-based biodegradable printing material and its preparation system provided in an embodiment of the present invention.

[0171] The bio-based biodegradable printing material and its preparation system 100 described in this invention can be installed in an electronic device. Depending on the functions implemented, the bio-based biodegradable printing material and its preparation system 100 may include a system confirmation and material preparation module 101, an esterification reaction control module 102, a polycondensation reaction management module 103, and a molding and drying treatment module 104. The module described in this invention can also be referred to as a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, and which are stored in the memory of the electronic device.

[0172] The system confirms the material preparation module 101, which is used to receive printing material preparation instructions and confirm the printing material production system according to the printing material preparation instructions. The printing material production system includes: a material conveying device, an esterification reaction device, a gas conduction device, a melt polycondensation device, a particle cutting device, a vacuum drying device, a hot pressing device, and a plasma treatment device. The esterification reaction device consists of an inlet end, a reaction end, and an exhaust end. It obtains bio-based raw materials and uses the material conveying device to transport the bio-based raw materials to the reaction end.

[0173] The esterification reaction control module 102 is used to set a water volume threshold, introduce nitrogen into the gas inlet using the gas conduction device, adjust the nitrogen flow rate in real time by monitoring the exhaust end, heat the bio-based raw material at the reaction end and carry out the esterification reaction, monitor the water volume generated by the esterification reaction device in real time, and stop the esterification reaction when the water volume generated reaches the set water volume threshold to obtain the esterification product.

[0174] The polycondensation reaction management module 103 is used to transport the esterification product to the melt polycondensation device, set the target vacuum degree and target torque value, continue to heat the esterification product in the melt polycondensation device and perform vacuum treatment, monitor the vacuum degree in the melt polycondensation device in real time, and when the vacuum degree reaches the set target vacuum degree, stir the esterification product and carry out the melt polycondensation reaction, while monitoring the stirring torque during the stirring process. When the stirring torque reaches the set target torque value, stop heating, stirring and melt polycondensation reaction to obtain molten copolyester.

[0175] The molding and drying module 104 is used to cool and solidify the molten copolyester. The granulation device is used to cut the cooled and solidified molten copolyester into copolyester granules. The vacuum drying device is then used to perform vacuum drying on the copolyester granules to obtain dried copolyester granules. The hot pressing molding device is used to perform preheating, pressure holding and cooling treatment on the dried copolyester granules to obtain a cooled blank. The plasma treatment device is used to perform low-temperature plasma treatment on the cooled blank to obtain the target bio-based biodegradable printing material.

[0176] In detail, the modules in the bio-based biodegradable printing material and its preparation system 100 described in this embodiment of the invention employ the same methods as described above during use. Figure 1 The bio-based biodegradable printing materials and their preparation methods described herein use the same technical means and can produce the same technical effects, so they will not be repeated here.

[0177] like Figure 3 The diagram shown is a schematic representation of an electronic device that realizes a bio-based biodegradable printing material and its preparation method according to an embodiment of the present invention.

[0178] The electronic device 1 may include a processor 10, a memory 11 and a bus 12, and may also include a computer program stored in the memory 11 and executable on the processor 10, such as a program for bio-based biodegradable printing materials and their preparation methods.

[0179] The memory 11 includes at least one type of readable storage medium, such as flash memory, portable hard drive, multimedia card, card-type memory (e.g., SD or DX memory), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 11 can be an internal storage unit of the electronic device 1, such as a portable hard drive. In other embodiments, the memory 11 can be an external storage device of the electronic device 1, such as a plug-in portable hard drive, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the electronic device 1. Furthermore, the memory 11 includes both internal storage units and external storage devices of the electronic device 1. The memory 11 can be used not only to store application software and various types of data installed on the electronic device 1, such as the code of bio-based biodegradable printing materials and their preparation methods, but also to temporarily store data that has been output or will be output.

[0180] In some embodiments, the processor 10 may be composed of integrated circuits, such as a single packaged integrated circuit or multiple integrated circuits with the same or different functions, including combinations of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The processor 10 is the control unit of the electronic device, connecting various components of the entire electronic device through various interfaces and lines. It executes programs or modules stored in the memory 11 (e.g., programs for bio-based biodegradable printing materials and their preparation methods), and calls data stored in the memory 11 to perform various functions of the electronic device 1 and process data.

[0181] The bus 12 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus 12 can be divided into an address bus, a data bus, a control bus, etc. The bus 12 is configured to realize the connection and communication between the memory 11 and at least one processor 10, etc.

[0182] Figure 3 Only electronic devices with components are shown; it will be understood by those skilled in the art that... Figure 3The structure shown does not constitute a limitation on the electronic device 1, and may include fewer or more components than shown, or combine certain components, or have different component arrangements.

[0183] For example, although not shown, the electronic device 1 may also include a power supply (such as a battery) to power the various components. Preferably, the power supply can be logically connected to the at least one processor 10 through a power management device, thereby enabling functions such as charging management, discharging management, and power consumption management. The power supply may also include one or more DC or AC power supplies, recharging devices, power fault detection circuits, power converters or inverters, power status indicators, and other arbitrary components. The electronic device 1 may also include various sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be described in detail here.

[0184] Furthermore, the electronic device 1 may also include a network interface. Optionally, the network interface may include a wired interface and / or a wireless interface (such as a Wi-Fi interface, a Bluetooth interface, etc.), which is typically used to establish communication connections between the electronic device 1 and other electronic devices.

[0185] Optionally, the electronic device 1 may further include a user interface, which may be a display, an input unit (such as a keyboard), and optionally, a standard wired interface or a wireless interface. Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen, etc. The display may also be appropriately referred to as a screen or display unit, used to display information processed in the electronic device 1 and to display a visual user interface.

[0186] The program for bio-based biodegradable printing materials and their preparation method stored in the memory 11 of the electronic device 1 is a combination of multiple instructions. When run in the processor 10, it can achieve the following:

[0187] The system receives a printing material preparation instruction and confirms the printing material production system according to the instruction. The printing material production system includes: a material conveying device, an esterification reaction device, a gas conduction device, a melt polycondensation device, a particle cutting device, a vacuum drying device, a hot pressing device, and a plasma treatment device. The esterification reaction device consists of an inlet end, a reaction end, and an exhaust end.

[0188] Obtain bio-based raw materials and use the material conveying device to transport the bio-based raw materials to the reaction end;

[0189] A water volume threshold is set, and nitrogen is introduced into the gas inlet using the gas conduction device. The flow rate of nitrogen is adjusted in real time by monitoring the exhaust end. The bio-based raw material at the reaction end is heated and esterification reaction is carried out. The water volume generated by the esterification reaction device is monitored in real time. When the water volume generated reaches the set water volume threshold, the esterification reaction is stopped to obtain the esterification product.

[0190] The esterified product is transported to the melt polycondensation device. The target vacuum level and target torque value are set. The esterified product in the melt polycondensation device is heated and vacuum treatment is performed. The vacuum level in the melt polycondensation device is monitored in real time. When the vacuum level reaches the set target vacuum level, the esterified product is stirred and melt polycondensation reaction is carried out. At the same time, the stirring torque during the stirring process is monitored. When the stirring torque reaches the set target torque value, the heating, stirring and melt polycondensation reaction are stopped to obtain molten copolyester.

[0191] The molten copolyester is cooled and solidified, and the solidified molten copolyester is cut into copolyester particles using the particle cutting device. The copolyester particles are then vacuum dried using the vacuum drying device to obtain dried copolyester particles.

[0192] The dried copolyester particles are preheated, pressure-held, and cooled sequentially using the hot pressing molding device to obtain a cooled blank. The cooled blank is then subjected to low-temperature plasma treatment using the plasma treatment device to obtain the target bio-based biodegradable printing material.

[0193] Specifically, the processor 10's implementation method for the above instructions can be found in [reference needed]. Figures 1 to 3 The descriptions of the relevant steps in the corresponding embodiments are not repeated here.

[0194] Furthermore, if the modules / units integrated in the electronic device 1 are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. The computer-readable storage medium can be volatile or non-volatile. For example, the computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, or a read-only memory (ROM).

[0195] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor of an electronic device, can perform the following:

[0196] The system receives a printing material preparation instruction and confirms the printing material production system according to the instruction. The printing material production system includes: a material conveying device, an esterification reaction device, a gas conduction device, a melt polycondensation device, a particle cutting device, a vacuum drying device, a hot pressing device, and a plasma treatment device. The esterification reaction device consists of an inlet end, a reaction end, and an exhaust end.

[0197] Obtain bio-based raw materials and use the material conveying device to transport the bio-based raw materials to the reaction end;

[0198] A water volume threshold is set, and nitrogen is introduced into the gas inlet using the gas conduction device. The flow rate of nitrogen is adjusted in real time by monitoring the exhaust end. The bio-based raw material at the reaction end is heated and esterification reaction is carried out. The water volume generated by the esterification reaction device is monitored in real time. When the water volume generated reaches the set water volume threshold, the esterification reaction is stopped to obtain the esterification product.

[0199] The esterified product is transported to the melt polycondensation device. The target vacuum level and target torque value are set. The esterified product in the melt polycondensation device is heated and vacuum treatment is performed. The vacuum level in the melt polycondensation device is monitored in real time. When the vacuum level reaches the set target vacuum level, the esterified product is stirred and melt polycondensation reaction is carried out. At the same time, the stirring torque during the stirring process is monitored. When the stirring torque reaches the set target torque value, the heating, stirring and melt polycondensation reaction are stopped to obtain molten copolyester.

[0200] The molten copolyester is cooled and solidified, and the solidified molten copolyester is cut into copolyester particles using the particle cutting device. The copolyester particles are then vacuum dried using the vacuum drying device to obtain dried copolyester particles.

[0201] The dried copolyester particles are preheated, pressure-held, and cooled sequentially using the hot pressing molding device to obtain a cooled blank. The cooled blank is then subjected to low-temperature plasma treatment using the plasma treatment device to obtain the target bio-based biodegradable printing material.

[0202] In the embodiments provided by this invention, it should be understood that the disclosed devices, systems, and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative, and actual implementations may have other classification methods.

[0203] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0204] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional modules.

[0205] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0206] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A bio-based biodegradable printing material and its preparation method, characterized in that, The method includes: The system receives a printing material preparation instruction and confirms the printing material production system according to the instruction. The printing material production system includes: a material conveying device, an esterification reaction device, a gas conduction device, a melt polycondensation device, a particle cutting device, a vacuum drying device, a hot pressing device, and a plasma treatment device. The esterification reaction device consists of an inlet end, a reaction end, and an exhaust end. Obtain bio-based raw materials and use the material conveying device to transport the bio-based raw materials to the reaction end; A water volume threshold is set, and nitrogen is introduced into the gas inlet using the gas conduction device. The flow rate of nitrogen is adjusted in real time by monitoring the exhaust end. The bio-based raw material at the reaction end is heated and esterification reaction is carried out. The water volume generated by the esterification reaction device is monitored in real time. When the water volume generated reaches the set water volume threshold, the esterification reaction is stopped to obtain the esterification product. The esterified product is transported to the melt polycondensation device. The target vacuum level and target torque value are set. The esterified product in the melt polycondensation device is heated and vacuum treatment is performed. The vacuum level in the melt polycondensation device is monitored in real time. When the vacuum level reaches the set target vacuum level, the esterified product is stirred and melt polycondensation reaction is carried out. At the same time, the stirring torque during the stirring process is monitored. When the stirring torque reaches the set target torque value, the heating, stirring and melt polycondensation reaction are stopped to obtain molten copolyester. The molten copolyester is cooled and solidified, and the solidified molten copolyester is cut into copolyester particles using the particle cutting device. The copolyester particles are then vacuum dried using the vacuum drying device to obtain dried copolyester particles. The dried copolyester particles are preheated, pressure-held, and cooled sequentially using the hot pressing molding device to obtain a cooled blank. The cooled blank is then subjected to low-temperature plasma treatment using the plasma treatment device to obtain the target bio-based biodegradable printing material.

2. The bio-based biodegradable printing material and its preparation method as described in claim 1, characterized in that, The process of introducing nitrogen gas into the inlet using the gas conduction device and adjusting the nitrogen flow rate in real time by monitoring the exhaust end includes: The gas conduction device is confirmed to include an oxygen sensor, a coarse adjustment flow meter, a fine adjustment flow meter, and a nitrogen inlet pipeline, and the gas conduction device is connected to the esterification reaction device. Initialize the oxygen sensor and use the oxygen sensor to collect the oxygen content monitoring value at the exhaust end of the esterification reaction device in real time; Set a replacement completion threshold and a target oxygen content threshold, wherein the replacement completion threshold is lower than the target oxygen content threshold; The gas phase space volume of the esterification reaction apparatus and the required reaction temperature of the esterification reaction are obtained. The first nitrogen flow rate is calculated based on the gas phase space volume and the required reaction temperature. The coarse adjustment target flow rate is set based on the first nitrogen flow rate, wherein the coarse adjustment target flow rate is less than the first nitrogen flow rate. The coarse adjustment flow meter and the fine adjustment flow meter are integrated in series in the nitrogen inlet pipeline. The coarse adjustment flow meter is turned on to adjust the nitrogen flow rate to the coarse adjustment target flow rate. Then, the flow rate is compensated by the fine adjustment flow meter to compensate the nitrogen flow rate to the first nitrogen flow rate. The first nitrogen flow rate is used to replace the air in the esterification reaction device. Set a second nitrogen flow rate, wherein the second nitrogen flow rate is less than the first nitrogen flow rate. Compare the oxygen content monitoring value with the set replacement completion threshold in real time. When the oxygen content monitoring value is continuously lower than the replacement completion threshold, turn off the coarse adjustment flow meter and use the fine adjustment flow meter to switch the nitrogen flow rate to be maintained at the second nitrogen flow rate. Nitrogen gas is continuously introduced into the inlet at the second nitrogen flow rate until the esterification reaction experiment is completed.

3. The bio-based biodegradable printing material and its preparation method as described in claim 2, characterized in that, The initialization of the oxygen sensor, and the real-time acquisition of oxygen content monitoring values ​​at the exhaust end of the esterification reaction device using the oxygen sensor, includes: To verify the oxygen sensor, introduce oxygen-free calibration nitrogen gas with a purity ≥99.99% into the oxygen sensor. Once the output value of the oxygen sensor stabilizes, read the output value of the oxygen sensor at this time as the zero-point output value. Standard air is switched to the oxygen sensor, wherein the oxygen content of the standard air is known. When the output value of the oxygen sensor stabilizes, the output value of the oxygen sensor at this time is read as the range output value. Based on the zero-point output value, the range output value, and the known oxygen content of the standard air, a linear correspondence between the output value of the oxygen sensor and the oxygen content is established through a linear fitting algorithm. set up For each set of temperature values, the fitted relationship between the output value of the oxygen sensor and the oxygen content is obtained. Based on the fitted relationship, a temperature compensation function is further fitted to obtain the temperature compensation function. During the esterification reaction, the output value of the oxygen sensor is continuously collected, and the real-time gas temperature at the exhaust end of the esterification reaction device is obtained. The real-time gas temperature is substituted into the temperature compensation function to calculate the temperature compensation coefficient. The output value of the oxygen sensor is multiplied by the temperature compensation coefficient to obtain the real-time compensation output value. The real-time compensation output value is then substituted into the linear correspondence to convert the oxygen content monitoring value, thus completing the real-time oxygen content detection.

4. The bio-based biodegradable printing material and its preparation method as described in claim 3, characterized in that, The settings For each set of temperature values, the fitted relationship between the oxygen sensor output value and the oxygen content is obtained. Based on the fitted relationship, a temperature compensation function is further fitted, including: Record the output value of the oxygen sensor for each set of temperature values, and take the natural logarithm of the output value of the oxygen sensor for each set of temperature values; The temperature value and the output value after taking the natural logarithm were linearly fitted using the least squares method, and the fitting coefficient was calculated according to the following formula: ； in, The number of temperature value groups. For each group of temperature values, The output value of the oxygen sensor for each set of temperature values. and These are the fitting coefficients; According to the fitting coefficients and The temperature compensation function is constructed. ,in, This is the temperature compensation coefficient.

5. The bio-based biodegradable printing material and its preparation method as described in claim 2, characterized in that, The process of compensating the flow rate of nitrogen to the first nitrogen flow rate by performing flow compensation through the fine-tuning flow meter includes: Multiple instantaneous flow rates of nitrogen in the nitrogen inlet pipeline are continuously collected, and the instantaneous flow rates are processed by moving average filtering to obtain a unique actual flow rate value after filtering. Set the deviation dead zone threshold and adjustment step size, and calculate the difference between the actual flow rate and the first nitrogen flow rate to obtain the flow deviation; The absolute value of the flow deviation is compared with the deviation dead zone threshold: if the absolute value of the flow deviation is less than or equal to the deviation dead zone threshold, no adjustment is required; if the absolute value of the flow deviation is greater than the deviation dead zone threshold and the flow deviation is positive, the set flow of the fine-tuning flow meter is reduced by one adjustment step; if the absolute value of the flow deviation is greater than the deviation dead zone threshold and the flow deviation is negative, the set flow of the fine-tuning flow meter is increased by one adjustment step. After each fine-tuning of the flow meter's set flow rate is completed, the flow sampling, filtering, flow deviation calculation, and comparison adjustment process is automatically repeated until the absolute value of the flow deviation is always less than or equal to the deviation dead zone threshold. At this point, the flow compensation is considered complete, and the fine-tuning flow meter is kept at the current set flow rate.

6. The bio-based biodegradable printing material and its preparation method as described in claim 1, characterized in that, The process of performing low-temperature plasma treatment on the cooled blank using the plasma processing device to obtain the target bio-based biodegradable printing material includes: The cooled billet is completely immersed in anhydrous ethanol for ultrasonic cleaning to obtain a cleaned billet. After cleaning, the cleaned billet is removed and dried until there is no liquid residue on the surface of the billet to obtain a dried billet. The plasma processing device is confirmed to have a built-in high-voltage pulse power supply, a stainless steel electrode and a lower grounding electrode, wherein the stainless steel electrode is positioned above the lower grounding electrode. The dried blank is laid flat on the surface of the lower grounding electrode, and the discharge voltage, processing time and oxygen flow rate of the plasma treatment device are preset. Oxygen is introduced into the plasma processing device at the stated oxygen flow rate until the plasma processing device is filled with oxygen. The high-voltage pulse power supply is started with the discharge voltage value to cause the oxygen between the stainless steel electrode and the lower ground electrode to break down and discharge. The duration of the breakdown discharge is then timed, and the dried billet is subjected to low-temperature plasma treatment. When the duration of the breakdown discharge reaches the set processing time value, the high-voltage pulse power supply is turned off, the discharge is stopped, and the dried blank material after low-temperature plasma treatment is taken out to obtain the target bio-based biodegradable printing material.

7. The bio-based biodegradable printing material and its preparation method as described in claim 6, characterized in that, The process of completely immersing the cooled billet in anhydrous ethanol for ultrasonic cleaning to obtain a cleaned billet includes: Place the cooled billets in a single layer, without stacking or sticking together, into the cleaning container, and add anhydrous ethanol to the cleaning container to completely immerse the cooled billets in the anhydrous ethanol. The ultrasonic frequency, cleaning temperature, and cleaning time of the ultrasonic cleaning device are set according to the cooled blank material. Start the ultrasonic cleaning device and perform ultrasonic cleaning on the cooled billet according to the set cleaning temperature and ultrasonic frequency values. Continue cleaning according to the cleaning time value. After cleaning is completed, a cleaned billet is obtained. Remove the preform that was cleaned once, pour out the anhydrous ethanol from the cleaning container, clean the cleaning container, refill with anhydrous ethanol, completely immerse the preform that was cleaned once again, and repeat the ultrasonic cleaning process to obtain the preform that was cleaned twice. Take out the secondary cleaned billet and rinse it with anhydrous ethanol. After rinsing, the cleaned billet is obtained.

8. The bio-based biodegradable printing material and its preparation method as described in claim 6, characterized in that, The step of activating the high-voltage pulse power supply with the discharge voltage value to cause oxygen breakdown discharge between the stainless steel electrode and the lower grounding electrode includes: Confirm the high-voltage pulse power supply, and set the discharge voltage threshold and target discharge current of the high-voltage pulse power supply; Start the high-voltage pulse power supply, measure the power output voltage of the high-voltage pulse power supply, and boost the power output voltage. At the same time, collect the real-time gap voltage between the stainless steel electrode and the lower grounding electrode. When the real-time gap voltage reaches the discharge voltage threshold, the oxygen between the stainless steel electrode and the lower ground electrode undergoes initial ionization and breakdown, generating a discharge current, and the real-time current value of the discharge current is read. The difference between the real-time current value and the target discharge current is calculated to obtain the current deviation value; Determine the sign of the current deviation value. If the current deviation value is negative, continue to increase the output voltage of the high-voltage pulse power supply to increase the real-time current value. If the current deviation value is positive, then the output voltage of the high-voltage pulse power supply is reduced to decrease the real-time current value. After each voltage adjustment is completed, the above-mentioned real-time current value reading, current deviation value calculation and output voltage adjustment actions are repeated until the absolute value of the current deviation value is less than the preset current deviation threshold.

9. The bio-based biodegradable printing material and its preparation method as described in claim 8, characterized in that, The steps of activating the high-voltage pulse power supply, measuring the power output voltage of the high-voltage pulse power supply, and boosting the power output voltage include: Set the boost step size and maximum number of iterations, read the current output voltage of the high-voltage pulse power supply, and record the current output voltage as the initial voltage; Starting from the initial voltage, the voltage boosting action is performed sequentially, increasing the power supply output voltage by one boosting step each time. After a single boost is completed, the real-time voltage value of the power supply output voltage is re-acquired, and the number of boosts is accumulated. Determine whether the real-time voltage value has reached the discharge voltage threshold. If the real-time voltage value reaches or exceeds the discharge voltage threshold, stop the voltage boosting operation, accumulate the number of voltage boosting times, and complete the increase of the power supply output voltage. If the cumulative number of voltage boosts reaches the maximum number of iterations and the real-time voltage value still does not reach the discharge voltage threshold, the voltage boosting operation will be stopped and an alarm will be issued. If the real-time voltage value reaches or exceeds the discharge voltage threshold, the boost operation is stopped, and the power supply output voltage is raised.

10. A bio-based biodegradable printing material preparation system, characterized in that, The system includes: The system confirms the material preparation module, which is used to receive printing material preparation instructions and confirm the printing material production system according to the printing material preparation instructions. The printing material production system includes: a material conveying device, an esterification reaction device, a gas conduction device, a melt polycondensation device, a particle cutting device, a vacuum drying device, a hot pressing device, and a plasma treatment device. The esterification reaction device consists of an inlet end, a reaction end, and an exhaust end. It obtains bio-based raw materials and uses the material conveying device to transport the bio-based raw materials to the reaction end. An esterification reaction control module is used to set a water volume threshold, introduce nitrogen into the gas inlet using the gas conduction device, adjust the nitrogen flow rate in real time by monitoring the exhaust end, heat the bio-based raw material at the reaction end and carry out the esterification reaction, monitor the water volume generated by the esterification reaction device in real time, and stop the esterification reaction when the water volume generated reaches the set water volume threshold to obtain the esterification product. The polycondensation reaction management module is used to transport the esterification product to the melt polycondensation device, set the target vacuum degree and target torque value, continue to heat the esterification product in the melt polycondensation device and perform vacuum treatment, monitor the vacuum degree in the melt polycondensation device in real time, when the vacuum degree reaches the set target vacuum degree, stir the esterification product and carry out the melt polycondensation reaction, and monitor the stirring torque during the stirring process. When the stirring torque reaches the set target torque value, stop heating, stirring and melt polycondensation reaction to obtain molten copolyester; The molding and drying module is used to cool and solidify molten copolyester. The cooled and solidified molten copolyester is cut into copolyester particles using the particle cutting device. The copolyester particles are then vacuum dried using the vacuum drying device to obtain dried copolyester particles. The dried copolyester particles are then preheated, pressure-held, and cooled using the hot pressing molding device to obtain a cooled blank. The cooled blank is then subjected to low-temperature plasma treatment using the plasma treatment device to obtain the target bio-based biodegradable printing material.

Images